[v8,1/3] dmaengine: Add support for APM X-Gene SoC DMA engine driver

Commit Message

Rameshwar Prasad Sahu March 18, 2015, 1:47 p.m. UTC

This patch implements the APM X-Gene SoC DMA engine driver. The APM X-Gene
SoC DMA engine consists of 4 DMA channels for performing DMA operations.
These DMA operations include memory copy, scatter-gather memory copy,
raid5 xor, and raid6 p+q offloading.

Signed-off-by: Rameshwar Prasad Sahu <[e-mail]>
Signed-off-by: Loc Ho <[e-mail]>
---
 drivers/dma/Kconfig     |    8 +
 drivers/dma/Makefile    |    1 +
 drivers/dma/xgene-dma.c | 2090 +++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 2099 insertions(+)
 create mode 100755 drivers/dma/xgene-dma.c

--
1.8.2.1

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Comments

Rameshwar Prasad Sahu March 19, 2015, 8:17 a.m. UTC | #1

Hi Vinod,

On Wed, Mar 18, 2015 at 7:17 PM, Rameshwar Prasad Sahu <[e-mail]> wrote:
> This patch implements the APM X-Gene SoC DMA engine driver. The APM X-Gene
> SoC DMA engine consists of 4 DMA channels for performing DMA operations.
> These DMA operations include memory copy, scatter-gather memory copy,
> raid5 xor, and raid6 p+q offloading.
>
> Signed-off-by: Rameshwar Prasad Sahu <[e-mail]>
> Signed-off-by: Loc Ho <[e-mail]>
> ---
>  drivers/dma/Kconfig     |    8 +
>  drivers/dma/Makefile    |    1 +
>  drivers/dma/xgene-dma.c | 2090 +++++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 2099 insertions(+)
>  create mode 100755 drivers/dma/xgene-dma.c
>
> diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
> index a874b6e..a271346 100644
> --- a/drivers/dma/Kconfig
> +++ b/drivers/dma/Kconfig
> @@ -425,6 +425,14 @@ config IMG_MDC_DMA
>         help
>           Enable support for the IMG multi-threaded DMA controller (MDC).
>
> +config XGENE_DMA
> +       tristate "APM X-Gene DMA support"
> +       select DMA_ENGINE
> +       select DMA_ENGINE_RAID
> +       select ASYNC_TX_ENABLE_CHANNEL_SWITCH
> +       help
> +         Enable support for the APM X-Gene SoC DMA engine.
> +
>  config DMA_ENGINE
>         bool
>
> diff --git a/drivers/dma/Makefile b/drivers/dma/Makefile
> index f915f61..06c1576 100644
> --- a/drivers/dma/Makefile
> +++ b/drivers/dma/Makefile
> @@ -51,3 +51,4 @@ obj-$(CONFIG_INTEL_MIC_X100_DMA) += mic_x100_dma.o
>  obj-$(CONFIG_NBPFAXI_DMA) += nbpfaxi.o
>  obj-$(CONFIG_DMA_SUN6I) += sun6i-dma.o
>  obj-$(CONFIG_IMG_MDC_DMA) += img-mdc-dma.o
> +obj-$(CONFIG_XGENE_DMA) += xgene-dma.o
> diff --git a/drivers/dma/xgene-dma.c b/drivers/dma/xgene-dma.c
> new file mode 100755
> index 0000000..2383528
> --- /dev/null
> +++ b/drivers/dma/xgene-dma.c
> @@ -0,0 +1,2090 @@
> +/*
> + * Applied Micro X-Gene SoC DMA engine Driver
> + *
> + * Copyright (c) 2015, Applied Micro Circuits Corporation
> + * Authors: Rameshwar Prasad Sahu <[e-mail]>
> + *         Loc Ho <[e-mail]>
> + *
> + * This program is free software; you can redistribute  it and/or modify it
> + * under  the terms of  the GNU General  Public License as published by the
> + * Free Software Foundation;  either version 2 of the  License, or (at your
> + * option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program.  If not, see <http://www.gnu.org/licenses/>.
> + *
> + * NOTE: PM support is currently not available.
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/delay.h>
> +#include <linux/dma-mapping.h>
> +#include <linux/dmaengine.h>
> +#include <linux/dmapool.h>
> +#include <linux/interrupt.h>
> +#include <linux/io.h>
> +#include <linux/module.h>
> +#include <linux/of_device.h>
> +
> +#include "dmaengine.h"
> +
> +/* X-Gene DMA ring csr registers and bit definations */
> +#define XGENE_DMA_RING_CONFIG                  0x04
> +#define XGENE_DMA_RING_ENABLE                  BIT(31)
> +#define XGENE_DMA_RING_ID                      0x08
> +#define XGENE_DMA_RING_ID_SETUP(v)             ((v) | BIT(31))
> +#define XGENE_DMA_RING_ID_BUF                  0x0C
> +#define XGENE_DMA_RING_ID_BUF_SETUP(v)         (((v) << 9) | BIT(21))
> +#define XGENE_DMA_RING_THRESLD0_SET1           0x30
> +#define XGENE_DMA_RING_THRESLD0_SET1_VAL       0X64
> +#define XGENE_DMA_RING_THRESLD1_SET1           0x34
> +#define XGENE_DMA_RING_THRESLD1_SET1_VAL       0xC8
> +#define XGENE_DMA_RING_HYSTERESIS              0x68
> +#define XGENE_DMA_RING_HYSTERESIS_VAL          0xFFFFFFFF
> +#define XGENE_DMA_RING_STATE                   0x6C
> +#define XGENE_DMA_RING_STATE_WR_BASE           0x70
> +#define XGENE_DMA_RING_NE_INT_MODE             0x017C
> +#define XGENE_DMA_RING_NE_INT_MODE_SET(m, v)   \
> +       ((m) = ((m) & ~BIT(31 - (v))) | BIT(31 - (v)))
> +#define XGENE_DMA_RING_NE_INT_MODE_RESET(m, v) \
> +       ((m) &= (~BIT(31 - (v))))
> +#define XGENE_DMA_RING_CLKEN                   0xC208
> +#define XGENE_DMA_RING_SRST                    0xC200
> +#define XGENE_DMA_RING_MEM_RAM_SHUTDOWN                0xD070
> +#define XGENE_DMA_RING_BLK_MEM_RDY             0xD074
> +#define XGENE_DMA_RING_BLK_MEM_RDY_VAL         0xFFFFFFFF
> +#define XGENE_DMA_RING_DESC_CNT(v)             (((v) & 0x0001FFFE) >> 1)
> +#define XGENE_DMA_RING_ID_GET(owner, num)      (((owner) << 6) | (num))
> +#define XGENE_DMA_RING_DST_ID(v)               ((1 << 10) | (v))
> +#define XGENE_DMA_RING_CMD_OFFSET              0x2C
> +#define XGENE_DMA_RING_CMD_BASE_OFFSET(v)      ((v) << 6)
> +#define XGENE_DMA_RING_COHERENT_SET(m)         \
> +       (((u32 *)(m))[2] |= BIT(4))
> +#define XGENE_DMA_RING_ADDRL_SET(m, v)         \
> +       (((u32 *)(m))[2] |= (((v) >> 8) << 5))
> +#define XGENE_DMA_RING_ADDRH_SET(m, v)         \
> +       (((u32 *)(m))[3] |= ((v) >> 35))
> +#define XGENE_DMA_RING_ACCEPTLERR_SET(m)       \
> +       (((u32 *)(m))[3] |= BIT(19))
> +#define XGENE_DMA_RING_SIZE_SET(m, v)          \
> +       (((u32 *)(m))[3] |= ((v) << 23))
> +#define XGENE_DMA_RING_RECOMBBUF_SET(m)                \
> +       (((u32 *)(m))[3] |= BIT(27))
> +#define XGENE_DMA_RING_RECOMTIMEOUTL_SET(m)    \
> +       (((u32 *)(m))[3] |= (0x7 << 28))
> +#define XGENE_DMA_RING_RECOMTIMEOUTH_SET(m)    \
> +       (((u32 *)(m))[4] |= 0x3)
> +#define XGENE_DMA_RING_SELTHRSH_SET(m)         \
> +       (((u32 *)(m))[4] |= BIT(3))
> +#define XGENE_DMA_RING_TYPE_SET(m, v)          \
> +       (((u32 *)(m))[4] |= ((v) << 19))
> +
> +/* X-Gene DMA device csr registers and bit definitions */
> +#define XGENE_DMA_IPBRR                                0x0
> +#define XGENE_DMA_DEV_ID_RD(v)                 ((v) & 0x00000FFF)
> +#define XGENE_DMA_BUS_ID_RD(v)                 (((v) >> 12) & 3)
> +#define XGENE_DMA_REV_NO_RD(v)                 (((v) >> 14) & 3)
> +#define XGENE_DMA_GCR                          0x10
> +#define XGENE_DMA_CH_SETUP(v)                  \
> +       ((v) = ((v) & ~0x000FFFFF) | 0x000AAFFF)
> +#define XGENE_DMA_ENABLE(v)                    ((v) |= BIT(31))
> +#define XGENE_DMA_DISABLE(v)                   ((v) &= ~BIT(31))
> +#define XGENE_DMA_RAID6_CONT                   0x14
> +#define XGENE_DMA_RAID6_MULTI_CTRL(v)          ((v) << 24)
> +#define XGENE_DMA_INT                          0x70
> +#define XGENE_DMA_INT_MASK                     0x74
> +#define XGENE_DMA_INT_ALL_MASK                 0xFFFFFFFF
> +#define XGENE_DMA_INT_ALL_UNMASK               0x0
> +#define XGENE_DMA_INT_MASK_SHIFT               0x14
> +#define XGENE_DMA_RING_INT0_MASK               0x90A0
> +#define XGENE_DMA_RING_INT1_MASK               0x90A8
> +#define XGENE_DMA_RING_INT2_MASK               0x90B0
> +#define XGENE_DMA_RING_INT3_MASK               0x90B8
> +#define XGENE_DMA_RING_INT4_MASK               0x90C0
> +#define XGENE_DMA_CFG_RING_WQ_ASSOC            0x90E0
> +#define XGENE_DMA_ASSOC_RING_MNGR1             0xFFFFFFFF
> +#define XGENE_DMA_MEM_RAM_SHUTDOWN             0xD070
> +#define XGENE_DMA_BLK_MEM_RDY                  0xD074
> +#define XGENE_DMA_BLK_MEM_RDY_VAL              0xFFFFFFFF
> +
> +/* X-Gene SoC EFUSE csr register and bit defination */
> +#define XGENE_SOC_JTAG1_SHADOW                 0x18
> +#define XGENE_DMA_PQ_DISABLE_MASK              BIT(13)
> +
> +/* X-Gene DMA Descriptor format */
> +#define XGENE_DMA_DESC_NV_BIT                  BIT_ULL(50)
> +#define XGENE_DMA_DESC_IN_BIT                  BIT_ULL(55)
> +#define XGENE_DMA_DESC_C_BIT                   BIT_ULL(63)
> +#define XGENE_DMA_DESC_DR_BIT                  BIT_ULL(61)
> +#define XGENE_DMA_DESC_ELERR_POS               46
> +#define XGENE_DMA_DESC_RTYPE_POS               56
> +#define XGENE_DMA_DESC_LERR_POS                        60
> +#define XGENE_DMA_DESC_FLYBY_POS               4
> +#define XGENE_DMA_DESC_BUFLEN_POS              48
> +#define XGENE_DMA_DESC_HOENQ_NUM_POS           48
> +
> +#define XGENE_DMA_DESC_NV_SET(m)               \
> +       (((u64 *)(m))[0] |= XGENE_DMA_DESC_NV_BIT)
> +#define XGENE_DMA_DESC_IN_SET(m)               \
> +       (((u64 *)(m))[0] |= XGENE_DMA_DESC_IN_BIT)
> +#define XGENE_DMA_DESC_RTYPE_SET(m, v)         \
> +       (((u64 *)(m))[0] |= ((u64)(v) << XGENE_DMA_DESC_RTYPE_POS))
> +#define XGENE_DMA_DESC_BUFADDR_SET(m, v)       \
> +       (((u64 *)(m))[0] |= (v))
> +#define XGENE_DMA_DESC_BUFLEN_SET(m, v)                \
> +       (((u64 *)(m))[0] |= ((u64)(v) << XGENE_DMA_DESC_BUFLEN_POS))
> +#define XGENE_DMA_DESC_C_SET(m)                        \
> +       (((u64 *)(m))[1] |= XGENE_DMA_DESC_C_BIT)
> +#define XGENE_DMA_DESC_FLYBY_SET(m, v)         \
> +       (((u64 *)(m))[2] |= ((v) << XGENE_DMA_DESC_FLYBY_POS))
> +#define XGENE_DMA_DESC_MULTI_SET(m, v, i)      \
> +       (((u64 *)(m))[2] |= ((u64)(v) << (((i) + 1) * 8)))
> +#define XGENE_DMA_DESC_DR_SET(m)               \
> +       (((u64 *)(m))[2] |= XGENE_DMA_DESC_DR_BIT)
> +#define XGENE_DMA_DESC_DST_ADDR_SET(m, v)      \
> +       (((u64 *)(m))[3] |= (v))
> +#define XGENE_DMA_DESC_H0ENQ_NUM_SET(m, v)     \
> +       (((u64 *)(m))[3] |= ((u64)(v) << XGENE_DMA_DESC_HOENQ_NUM_POS))
> +#define XGENE_DMA_DESC_ELERR_RD(m)             \
> +       (((m) >> XGENE_DMA_DESC_ELERR_POS) & 0x3)
> +#define XGENE_DMA_DESC_LERR_RD(m)              \
> +       (((m) >> XGENE_DMA_DESC_LERR_POS) & 0x7)
> +#define XGENE_DMA_DESC_STATUS(elerr, lerr)     \
> +       (((elerr) << 4) | (lerr))
> +
> +/* X-Gene DMA descriptor empty s/w signature */
> +#define XGENE_DMA_DESC_EMPTY_INDEX             0
> +#define XGENE_DMA_DESC_EMPTY_SIGNATURE         ~0ULL
> +#define XGENE_DMA_DESC_SET_EMPTY(m)            \
> +       (((u64 *)(m))[XGENE_DMA_DESC_EMPTY_INDEX] =     \
> +        XGENE_DMA_DESC_EMPTY_SIGNATURE)
> +#define XGENE_DMA_DESC_IS_EMPTY(m)             \
> +       (((u64 *)(m))[XGENE_DMA_DESC_EMPTY_INDEX] ==    \
> +        XGENE_DMA_DESC_EMPTY_SIGNATURE)
> +
> +/* X-Gene DMA configurable parameters defines */
> +#define XGENE_DMA_RING_NUM             512
> +#define XGENE_DMA_BUFNUM               0x0
> +#define XGENE_DMA_CPU_BUFNUM           0x18
> +#define XGENE_DMA_RING_OWNER_DMA       0x03
> +#define XGENE_DMA_RING_OWNER_CPU       0x0F
> +#define XGENE_DMA_RING_TYPE_REGULAR    0x01
> +#define XGENE_DMA_RING_WQ_DESC_SIZE    32      /* 32 Bytes */
> +#define XGENE_DMA_RING_NUM_CONFIG      5
> +#define XGENE_DMA_MAX_CHANNEL          4
> +#define XGENE_DMA_XOR_CHANNEL          0
> +#define XGENE_DMA_PQ_CHANNEL           1
> +#define XGENE_DMA_MAX_BYTE_CNT         0x4000  /* 16 KB */
> +#define XGENE_DMA_MAX_64B_DESC_BYTE_CNT        0x14000 /* 80 KB */
> +#define XGENE_DMA_XOR_ALIGNMENT                6       /* 64 Bytes */
> +#define XGENE_DMA_MAX_XOR_SRC          5
> +#define XGENE_DMA_16K_BUFFER_LEN_CODE  0x0
> +#define XGENE_DMA_INVALID_LEN_CODE     0x7800
> +
> +/* X-Gene DMA descriptor error codes */
> +#define ERR_DESC_AXI                   0x01
> +#define ERR_BAD_DESC                   0x02
> +#define ERR_READ_DATA_AXI              0x03
> +#define ERR_WRITE_DATA_AXI             0x04
> +#define ERR_FBP_TIMEOUT                        0x05
> +#define ERR_ECC                                0x06
> +#define ERR_DIFF_SIZE                  0x08
> +#define ERR_SCT_GAT_LEN                        0x09
> +#define ERR_CRC_ERR                    0x11
> +#define ERR_CHKSUM                     0x12
> +#define ERR_DIF                                0x13
> +
> +/* X-Gene DMA error interrupt codes */
> +#define ERR_DIF_SIZE_INT               0x0
> +#define ERR_GS_ERR_INT                 0x1
> +#define ERR_FPB_TIMEO_INT              0x2
> +#define ERR_WFIFO_OVF_INT              0x3
> +#define ERR_RFIFO_OVF_INT              0x4
> +#define ERR_WR_TIMEO_INT               0x5
> +#define ERR_RD_TIMEO_INT               0x6
> +#define ERR_WR_ERR_INT                 0x7
> +#define ERR_RD_ERR_INT                 0x8
> +#define ERR_BAD_DESC_INT               0x9
> +#define ERR_DESC_DST_INT               0xA
> +#define ERR_DESC_SRC_INT               0xB
> +
> +/* X-Gene DMA flyby operation code */
> +#define FLYBY_2SRC_XOR                 0x8
> +#define FLYBY_3SRC_XOR                 0x9
> +#define FLYBY_4SRC_XOR                 0xA
> +#define FLYBY_5SRC_XOR                 0xB
> +
> +/* X-Gene DMA SW descriptor flags */
> +#define XGENE_DMA_FLAG_64B_DESC                BIT(0)
> +
> +/* Define to dump X-Gene DMA descriptor */
> +#define XGENE_DMA_DESC_DUMP(desc, m)   \
> +       print_hex_dump(KERN_ERR, (m),   \
> +                       DUMP_PREFIX_ADDRESS, 16, 8, (desc), 32, 0)
> +
> +#define to_dma_desc_sw(tx)             \
> +       container_of(tx, struct xgene_dma_desc_sw, tx)
> +#define to_dma_chan(dchan)             \
> +       container_of(dchan, struct xgene_dma_chan, dma_chan)
> +
> +#define chan_dbg(chan, fmt, arg...)    \
> +       dev_dbg(chan->dev, "%s: " fmt, chan->name, ##arg)
> +#define chan_err(chan, fmt, arg...)    \
> +       dev_err(chan->dev, "%s: " fmt, chan->name, ##arg)
> +
> +struct xgene_dma_desc_hw {
> +       u64 m0;
> +       u64 m1;
> +       u64 m2;
> +       u64 m3;
> +};
> +
> +enum xgene_dma_ring_cfgsize {
> +       XGENE_DMA_RING_CFG_SIZE_512B,
> +       XGENE_DMA_RING_CFG_SIZE_2KB,
> +       XGENE_DMA_RING_CFG_SIZE_16KB,
> +       XGENE_DMA_RING_CFG_SIZE_64KB,
> +       XGENE_DMA_RING_CFG_SIZE_512KB,
> +       XGENE_DMA_RING_CFG_SIZE_INVALID
> +};
> +
> +struct xgene_dma_ring {
> +       struct xgene_dma *pdma;
> +       u8 buf_num;
> +       u16 id;
> +       u16 num;
> +       u16 head;
> +       u16 owner;
> +       u16 slots;
> +       u16 dst_ring_num;
> +       u32 size;
> +       void __iomem *cmd;
> +       void __iomem *cmd_base;
> +       dma_addr_t desc_paddr;
> +       u32 state[XGENE_DMA_RING_NUM_CONFIG];
> +       enum xgene_dma_ring_cfgsize cfgsize;
> +       union {
> +               void *desc_vaddr;
> +               struct xgene_dma_desc_hw *desc_hw;
> +       };
> +};
> +
> +struct xgene_dma_desc_sw {
> +       struct xgene_dma_desc_hw desc1;
> +       struct xgene_dma_desc_hw desc2;
> +       u32 flags;
> +       struct list_head node;
> +       struct list_head tx_list;
> +       struct dma_async_tx_descriptor tx;
> +};
> +
> +/**
> + * struct xgene_dma_chan - internal representation of an X-Gene DMA channel
> + * @dma_chan: dmaengine channel object member
> + * @pdma: X-Gene DMA device structure reference
> + * @dev: struct device reference for dma mapping api
> + * @id: raw id of this channel
> + * @rx_irq: channel IRQ
> + * @name: name of X-Gene DMA channel
> + * @lock: serializes enqueue/dequeue operations to the descriptor pool
> + * @pending: number of transaction request pushed to DMA controller for
> + *     execution, but still waiting for completion,
> + * @max_outstanding: max number of outstanding request we can push to channel
> + * @ld_pending: descriptors which are queued to run, but have not yet been
> + *     submitted to the hardware for execution
> + * @ld_running: descriptors which are currently being executing by the hardware
> + * @ld_completed: descriptors which have finished execution by the hardware.
> + *     These descriptors have already had their cleanup actions run. They
> + *     are waiting for the ACK bit to be set by the async tx API.
> + * @desc_pool: descriptor pool for DMA operations
> + * @tasklet: bottom half where all completed descriptors cleans
> + * @tx_ring: transmit ring descriptor that we use to prepare actual
> + *     descriptors for further executions
> + * @rx_ring: receive ring descriptor that we use to get completed DMA
> + *     descriptors during cleanup time
> + */
> +struct xgene_dma_chan {
> +       struct dma_chan dma_chan;
> +       struct xgene_dma *pdma;
> +       struct device *dev;
> +       int id;
> +       int rx_irq;
> +       char name[8];
> +       spinlock_t lock;
> +       int pending;
> +       int max_outstanding;
> +       struct list_head ld_pending;
> +       struct list_head ld_running;
> +       struct list_head ld_completed;
> +       struct dma_pool *desc_pool;
> +       struct tasklet_struct tasklet;
> +       struct xgene_dma_ring tx_ring;
> +       struct xgene_dma_ring rx_ring;
> +};
> +
> +/**
> + * struct xgene_dma - internal representation of an X-Gene DMA device
> + * @err_irq: DMA error irq number
> + * @ring_num: start id number for DMA ring
> + * @csr_dma: base for DMA register access
> + * @csr_ring: base for DMA ring register access
> + * @csr_ring_cmd: base for DMA ring command register access
> + * @csr_efuse: base for efuse register access
> + * @dma_dev: embedded struct dma_device
> + * @chan: reference to X-Gene DMA channels
> + */
> +struct xgene_dma {
> +       struct device *dev;
> +       struct clk *clk;
> +       int err_irq;
> +       int ring_num;
> +       void __iomem *csr_dma;
> +       void __iomem *csr_ring;
> +       void __iomem *csr_ring_cmd;
> +       void __iomem *csr_efuse;
> +       struct dma_device dma_dev[XGENE_DMA_MAX_CHANNEL];
> +       struct xgene_dma_chan chan[XGENE_DMA_MAX_CHANNEL];
> +};
> +
> +static const char * const xgene_dma_desc_err[] = {
> +       [ERR_DESC_AXI] = "AXI error when reading src/dst link list",
> +       [ERR_BAD_DESC] = "ERR or El_ERR fields not set to zero in desc",
> +       [ERR_READ_DATA_AXI] = "AXI error when reading data",
> +       [ERR_WRITE_DATA_AXI] = "AXI error when writing data",
> +       [ERR_FBP_TIMEOUT] = "Timeout on bufpool fetch",
> +       [ERR_ECC] = "ECC double bit error",
> +       [ERR_DIFF_SIZE] = "Bufpool too small to hold all the DIF result",
> +       [ERR_SCT_GAT_LEN] = "Gather and scatter data length not same",
> +       [ERR_CRC_ERR] = "CRC error",
> +       [ERR_CHKSUM] = "Checksum error",
> +       [ERR_DIF] = "DIF error",
> +};
> +
> +static const char * const xgene_dma_err[] = {
> +       [ERR_DIF_SIZE_INT] = "DIF size error",
> +       [ERR_GS_ERR_INT] = "Gather scatter not same size error",
> +       [ERR_FPB_TIMEO_INT] = "Free pool time out error",
> +       [ERR_WFIFO_OVF_INT] = "Write FIFO over flow error",
> +       [ERR_RFIFO_OVF_INT] = "Read FIFO over flow error",
> +       [ERR_WR_TIMEO_INT] = "Write time out error",
> +       [ERR_RD_TIMEO_INT] = "Read time out error",
> +       [ERR_WR_ERR_INT] = "HBF bus write error",
> +       [ERR_RD_ERR_INT] = "HBF bus read error",
> +       [ERR_BAD_DESC_INT] = "Ring descriptor HE0 not set error",
> +       [ERR_DESC_DST_INT] = "HFB reading dst link address error",
> +       [ERR_DESC_SRC_INT] = "HFB reading src link address error",
> +};
> +
> +static bool is_pq_enabled(struct xgene_dma *pdma)
> +{
> +       u32 val;
> +
> +       val = ioread32(pdma->csr_efuse + XGENE_SOC_JTAG1_SHADOW);
> +       return !(val & XGENE_DMA_PQ_DISABLE_MASK);
> +}
> +
> +static void xgene_dma_cpu_to_le64(u64 *desc, int count)
> +{
> +       int i;
> +
> +       for (i = 0; i < count; i++)
> +               desc[i] = cpu_to_le64(desc[i]);
> +}
> +
> +static u16 xgene_dma_encode_len(u32 len)
> +{
> +       return (len < XGENE_DMA_MAX_BYTE_CNT) ?
> +               len : XGENE_DMA_16K_BUFFER_LEN_CODE;
> +}
> +
> +static u8 xgene_dma_encode_xor_flyby(u32 src_cnt)
> +{
> +       static u8 flyby_type[] = {
> +               FLYBY_2SRC_XOR, /* Dummy */
> +               FLYBY_2SRC_XOR, /* Dummy */
> +               FLYBY_2SRC_XOR,
> +               FLYBY_3SRC_XOR,
> +               FLYBY_4SRC_XOR,
> +               FLYBY_5SRC_XOR
> +       };
> +
> +       return flyby_type[src_cnt];
> +}
> +
> +static u32 xgene_dma_ring_desc_cnt(struct xgene_dma_ring *ring)
> +{
> +       u32 __iomem *cmd_base = ring->cmd_base;
> +       u32 ring_state = ioread32(&cmd_base[1]);
> +
> +       return XGENE_DMA_RING_DESC_CNT(ring_state);
> +}
> +
> +static void xgene_dma_set_src_buffer(void *ext8, size_t *len,
> +                                    dma_addr_t *paddr)
> +{
> +       size_t nbytes = (*len < XGENE_DMA_MAX_BYTE_CNT) ?
> +                       *len : XGENE_DMA_MAX_BYTE_CNT;
> +
> +       XGENE_DMA_DESC_BUFADDR_SET(ext8, *paddr);
> +       XGENE_DMA_DESC_BUFLEN_SET(ext8, xgene_dma_encode_len(nbytes));
> +       *len -= nbytes;
> +       *paddr += nbytes;
> +}
> +
> +static void xgene_dma_invalidate_buffer(void *ext8)
> +{
> +       XGENE_DMA_DESC_BUFLEN_SET(ext8, XGENE_DMA_INVALID_LEN_CODE);
> +}
> +
> +static void *xgene_dma_lookup_ext8(u64 *desc, int idx)
> +{
> +       return (idx % 2) ? (desc + idx - 1) : (desc + idx + 1);
> +}
> +
> +static void xgene_dma_init_desc(void *desc, u16 dst_ring_num)
> +{
> +       XGENE_DMA_DESC_C_SET(desc); /* Coherent IO */
> +       XGENE_DMA_DESC_IN_SET(desc);
> +       XGENE_DMA_DESC_H0ENQ_NUM_SET(desc, dst_ring_num);
> +       XGENE_DMA_DESC_RTYPE_SET(desc, XGENE_DMA_RING_OWNER_DMA);
> +}
> +
> +static void xgene_dma_prep_cpy_desc(struct xgene_dma_chan *chan,
> +                                   struct xgene_dma_desc_sw *desc_sw,
> +                                   dma_addr_t dst, dma_addr_t src,
> +                                   size_t len)
> +{
> +       void *desc1, *desc2;
> +       int i;
> +
> +       /* Get 1st descriptor */
> +       desc1 = &desc_sw->desc1;
> +       xgene_dma_init_desc(desc1, chan->tx_ring.dst_ring_num);
> +
> +       /* Set destination address */
> +       XGENE_DMA_DESC_DR_SET(desc1);
> +       XGENE_DMA_DESC_DST_ADDR_SET(desc1, dst);
> +
> +       /* Set 1st source address */
> +       xgene_dma_set_src_buffer(desc1 + 8, &len, &src);
> +
> +       if (len <= 0) {
> +               desc2 = NULL;
> +               goto skip_additional_src;
> +       }
> +
> +       /*
> +        * We need to split this source buffer,
> +        * and need to use 2nd descriptor
> +        */
> +       desc2 = &desc_sw->desc2;
> +       XGENE_DMA_DESC_NV_SET(desc1);
> +
> +       /* Set 2nd to 5th source address */
> +       for (i = 0; i < 4 && len; i++)
> +               xgene_dma_set_src_buffer(xgene_dma_lookup_ext8(desc2, i),
> +                                        &len, &src);
> +
> +       /* Invalidate unused source address field */
> +       for (; i < 4; i++)
> +               xgene_dma_invalidate_buffer(xgene_dma_lookup_ext8(desc2, i));
> +
> +       /* Updated flag that we have prepared 64B descriptor */
> +       desc_sw->flags |= XGENE_DMA_FLAG_64B_DESC;
> +
> +skip_additional_src:
> +       /* Hardware stores descriptor in little endian format */
> +       xgene_dma_cpu_to_le64(desc1, 4);
> +       if (desc2)
> +               xgene_dma_cpu_to_le64(desc2, 4);
> +}
> +
> +static void xgene_dma_prep_xor_desc(struct xgene_dma_chan *chan,
> +                                   struct xgene_dma_desc_sw *desc_sw,
> +                                   dma_addr_t *dst, dma_addr_t *src,
> +                                   u32 src_cnt, size_t *nbytes,
> +                                   const u8 *scf)
> +{
> +       void *desc1, *desc2;
> +       size_t len = *nbytes;
> +       int i;
> +
> +       desc1 = &desc_sw->desc1;
> +       desc2 = &desc_sw->desc2;
> +
> +       /* Initialize DMA descriptor */
> +       xgene_dma_init_desc(desc1, chan->tx_ring.dst_ring_num);
> +
> +       /* Set destination address */
> +       XGENE_DMA_DESC_DR_SET(desc1);
> +       XGENE_DMA_DESC_DST_ADDR_SET(desc1, *dst);
> +
> +       /* We have multiple source addresses, so need to set NV bit*/
> +       XGENE_DMA_DESC_NV_SET(desc1);
> +
> +       /* Set flyby opcode */
> +       XGENE_DMA_DESC_FLYBY_SET(desc1, xgene_dma_encode_xor_flyby(src_cnt));
> +
> +       /* Set 1st to 5th source addresses */
> +       for (i = 0; i < src_cnt; i++) {
> +               len = *nbytes;
> +               xgene_dma_set_src_buffer((i == 0) ? (desc1 + 8) :
> +                                        xgene_dma_lookup_ext8(desc2, i - 1),
> +                                        &len, &src[i]);
> +               XGENE_DMA_DESC_MULTI_SET(desc1, scf[i], i);
> +       }
> +
> +       /* Hardware stores descriptor in little endian format */
> +       xgene_dma_cpu_to_le64(desc1, 4);
> +       xgene_dma_cpu_to_le64(desc2, 4);
> +
> +       /* Update meta data */
> +       *nbytes = len;
> +       *dst += XGENE_DMA_MAX_BYTE_CNT;
> +
> +       /* We need always 64B descriptor to perform xor or pq operations */
> +       desc_sw->flags |= XGENE_DMA_FLAG_64B_DESC;
> +}
> +
> +static dma_cookie_t xgene_dma_tx_submit(struct dma_async_tx_descriptor *tx)
> +{
> +       struct xgene_dma_desc_sw *desc;
> +       struct xgene_dma_chan *chan;
> +       dma_cookie_t cookie;
> +
> +       if (unlikely(!tx))
> +               return -EINVAL;
> +
> +       chan = to_dma_chan(tx->chan);
> +       desc = to_dma_desc_sw(tx);
> +
> +       spin_lock_bh(&chan->lock);
> +
> +       cookie = dma_cookie_assign(tx);
> +
> +       /* Add this transaction list onto the tail of the pending queue */
> +       list_splice_tail_init(&desc->tx_list, &chan->ld_pending);
> +
> +       spin_unlock_bh(&chan->lock);
> +
> +       return cookie;
> +}
> +
> +static void xgene_dma_clean_descriptor(struct xgene_dma_chan *chan,
> +                                      struct xgene_dma_desc_sw *desc)
> +{
> +       list_del(&desc->node);
> +       chan_dbg(chan, "LD %p free\n", desc);
> +       dma_pool_free(chan->desc_pool, desc, desc->tx.phys);
> +}
> +
> +static struct xgene_dma_desc_sw *xgene_dma_alloc_descriptor(
> +                                struct xgene_dma_chan *chan)
> +{
> +       struct xgene_dma_desc_sw *desc;
> +       dma_addr_t phys;
> +
> +       desc = dma_pool_alloc(chan->desc_pool, GFP_NOWAIT, &phys);
> +       if (!desc) {
> +               chan_err(chan, "Failed to allocate LDs\n");
> +               return NULL;
> +       }
> +
> +       memset(desc, 0, sizeof(*desc));
> +
> +       INIT_LIST_HEAD(&desc->tx_list);
> +       desc->tx.phys = phys;
> +       desc->tx.tx_submit = xgene_dma_tx_submit;
> +       dma_async_tx_descriptor_init(&desc->tx, &chan->dma_chan);
> +
> +       chan_dbg(chan, "LD %p allocated\n", desc);
> +
> +       return desc;
> +}
> +
> +/**
> + * xgene_dma_clean_completed_descriptor - free all descriptors which
> + * has been completed and acked
> + * @chan: X-Gene DMA channel
> + *
> + * This function is used on all completed and acked descriptors.
> + */
> +static void xgene_dma_clean_completed_descriptor(struct xgene_dma_chan *chan)
> +{
> +       struct xgene_dma_desc_sw *desc, *_desc;
> +
> +       /* Run the callback for each descriptor, in order */
> +       list_for_each_entry_safe(desc, _desc, &chan->ld_completed, node) {
> +               if (async_tx_test_ack(&desc->tx))
> +                       xgene_dma_clean_descriptor(chan, desc);
> +       }
> +}
> +
> +/**
> + * xgene_dma_run_tx_complete_actions - cleanup a single link descriptor
> + * @chan: X-Gene DMA channel
> + * @desc: descriptor to cleanup and free
> + *
> + * This function is used on a descriptor which has been executed by the DMA
> + * controller. It will run any callbacks, submit any dependencies.
> + */
> +static void xgene_dma_run_tx_complete_actions(struct xgene_dma_chan *chan,
> +                                             struct xgene_dma_desc_sw *desc)
> +{
> +       struct dma_async_tx_descriptor *tx = &desc->tx;
> +
> +       /*
> +        * If this is not the last transaction in the group,
> +        * then no need to complete cookie and run any callback as
> +        * this is not the tx_descriptor which had been sent to caller
> +        * of this DMA request
> +        */
> +
> +       if (tx->cookie == 0)
> +               return;
> +
> +       dma_cookie_complete(tx);
> +
> +       /* Run the link descriptor callback function */
> +       if (tx->callback)
> +               tx->callback(tx->callback_param);
> +
> +       dma_descriptor_unmap(tx);
> +
> +       /* Run any dependencies */
> +       dma_run_dependencies(tx);
> +}
> +
> +/**
> + * xgene_dma_clean_running_descriptor - move the completed descriptor from
> + * ld_running to ld_completed
> + * @chan: X-Gene DMA channel
> + * @desc: the descriptor which is completed
> + *
> + * Free the descriptor directly if acked by async_tx api,
> + * else move it to queue ld_completed.
> + */
> +static void xgene_dma_clean_running_descriptor(struct xgene_dma_chan *chan,
> +                                              struct xgene_dma_desc_sw *desc)
> +{
> +       /* Remove from the list of running transactions */
> +       list_del(&desc->node);
> +
> +       /*
> +        * the client is allowed to attach dependent operations
> +        * until 'ack' is set
> +        */
> +       if (!async_tx_test_ack(&desc->tx)) {
> +               /*
> +                * Move this descriptor to the list of descriptors which is
> +                * completed, but still awaiting the 'ack' bit to be set.
> +                */
> +               list_add_tail(&desc->node, &chan->ld_completed);
> +               return;
> +       }
> +
> +       chan_dbg(chan, "LD %p free\n", desc);
> +       dma_pool_free(chan->desc_pool, desc, desc->tx.phys);
> +}
> +
> +static int xgene_chan_xfer_request(struct xgene_dma_ring *ring,
> +                                  struct xgene_dma_desc_sw *desc_sw)
> +{
> +       struct xgene_dma_desc_hw *desc_hw;
> +
> +       /* Check if can push more descriptor to hw for execution */
> +       if (xgene_dma_ring_desc_cnt(ring) > (ring->slots - 2))
> +               return -EBUSY;
> +
> +       /* Get hw descriptor from DMA tx ring */
> +       desc_hw = &ring->desc_hw[ring->head];
> +
> +       /*
> +        * Increment the head count to point next
> +        * descriptor for next time
> +        */
> +       if (++ring->head == ring->slots)
> +               ring->head = 0;
> +
> +       /* Copy prepared sw descriptor data to hw descriptor */
> +       memcpy(desc_hw, &desc_sw->desc1, sizeof(*desc_hw));
> +
> +       /*
> +        * Check if we have prepared 64B descriptor,
> +        * in this case we need one more hw descriptor
> +        */
> +       if (desc_sw->flags & XGENE_DMA_FLAG_64B_DESC) {
> +               desc_hw = &ring->desc_hw[ring->head];
> +
> +               if (++ring->head == ring->slots)
> +                       ring->head = 0;
> +
> +               memcpy(desc_hw, &desc_sw->desc2, sizeof(*desc_hw));
> +       }
> +
> +       /* Notify the hw that we have descriptor ready for execution */
> +       iowrite32((desc_sw->flags & XGENE_DMA_FLAG_64B_DESC) ?
> +                 2 : 1, ring->cmd);
> +
> +       return 0;
> +}
> +
> +/**
> + * xgene_chan_xfer_ld_pending - push any pending transactions to hw
> + * @chan : X-Gene DMA channel
> + *
> + * LOCKING: must hold chan->desc_lock
> + */
> +static void xgene_chan_xfer_ld_pending(struct xgene_dma_chan *chan)
> +{
> +       struct xgene_dma_desc_sw *desc_sw, *_desc_sw;
> +       int ret;
> +
> +       /*
> +        * If the list of pending descriptors is empty, then we
> +        * don't need to do any work at all
> +        */
> +       if (list_empty(&chan->ld_pending)) {
> +               chan_dbg(chan, "No pending LDs\n");
> +               return;
> +       }
> +
> +       /*
> +        * Move elements from the queue of pending transactions onto the list
> +        * of running transactions and push it to hw for further executions
> +        */
> +       list_for_each_entry_safe(desc_sw, _desc_sw, &chan->ld_pending, node) {
> +               /*
> +                * Check if have pushed max number of transactions to hw
> +                * as capable, so let's stop here and will push remaining
> +                * elements from pening ld queue after completing some
> +                * descriptors that we have already pushed
> +                */
> +               if (chan->pending >= chan->max_outstanding)
> +                       return;
> +
> +               ret = xgene_chan_xfer_request(&chan->tx_ring, desc_sw);
> +               if (ret)
> +                       return;
> +
> +               /*
> +                * Delete this element from ld pending queue and append it to
> +                * ld running queue
> +                */
> +               list_move_tail(&desc_sw->node, &chan->ld_running);
> +
> +               /* Increment the pending transaction count */
> +               chan->pending++;
> +       }
> +}
> +
> +/**
> + * xgene_dma_cleanup_descriptors - cleanup link descriptors which are completed
> + * and move them to ld_completed to free until flag 'ack' is set
> + * @chan: X-Gene DMA channel
> + *
> + * This function is used on descriptors which have been executed by the DMA
> + * controller. It will run any callbacks, submit any dependencies, then
> + * free these descriptors if flag 'ack' is set.
> + */
> +static void xgene_dma_cleanup_descriptors(struct xgene_dma_chan *chan)
> +{
> +       struct xgene_dma_ring *ring = &chan->rx_ring;
> +       struct xgene_dma_desc_sw *desc_sw, *_desc_sw;
> +       struct xgene_dma_desc_hw *desc_hw;
> +       u8 status;
> +
> +       /* Clean already completed and acked descriptors */
> +       xgene_dma_clean_completed_descriptor(chan);
> +
> +       /* Run the callback for each descriptor, in order */
> +       list_for_each_entry_safe(desc_sw, _desc_sw, &chan->ld_running, node) {
> +               /* Get subsequent hw descriptor from DMA rx ring */
> +               desc_hw = &ring->desc_hw[ring->head];
> +
> +               /* Check if this descriptor has been completed */
> +               if (unlikely(XGENE_DMA_DESC_IS_EMPTY(desc_hw)))
> +                       break;
> +
> +               if (++ring->head == ring->slots)
> +                       ring->head = 0;
> +
> +               /* Check if we have any error with DMA transactions */
> +               status = XGENE_DMA_DESC_STATUS(
> +                               XGENE_DMA_DESC_ELERR_RD(le64_to_cpu(
> +                                                       desc_hw->m0)),
> +                               XGENE_DMA_DESC_LERR_RD(le64_to_cpu(
> +                                                      desc_hw->m0)));
> +               if (status) {
> +                       /* Print the DMA error type */
> +                       chan_err(chan, "%s\n", xgene_dma_desc_err[status]);
> +
> +                       /*
> +                        * We have DMA transactions error here. Dump DMA Tx
> +                        * and Rx descriptors for this request */
> +                       XGENE_DMA_DESC_DUMP(&desc_sw->desc1,
> +                                           "X-Gene DMA TX DESC1: ");
> +
> +                       if (desc_sw->flags & XGENE_DMA_FLAG_64B_DESC)
> +                               XGENE_DMA_DESC_DUMP(&desc_sw->desc2,
> +                                                   "X-Gene DMA TX DESC2: ");
> +
> +                       XGENE_DMA_DESC_DUMP(desc_hw,
> +                                           "X-Gene DMA RX ERR DESC: ");
> +               }
> +
> +               /* Notify the hw about this completed descriptor */
> +               iowrite32(-1, ring->cmd);
> +
> +               /* Mark this hw descriptor as processed */
> +               XGENE_DMA_DESC_SET_EMPTY(desc_hw);
> +
> +               xgene_dma_run_tx_complete_actions(chan, desc_sw);
> +
> +               xgene_dma_clean_running_descriptor(chan, desc_sw);
> +
> +               /*
> +                * Decrement the pending transaction count
> +                * as we have processed one
> +                */
> +               chan->pending--;
> +       }
> +
> +       /*
> +        * Start any pending transactions automatically
> +        * In the ideal case, we keep the DMA controller busy while we go
> +        * ahead and free the descriptors below.
> +        */
> +       xgene_chan_xfer_ld_pending(chan);
> +}
> +
> +static int xgene_dma_alloc_chan_resources(struct dma_chan *dchan)
> +{
> +       struct xgene_dma_chan *chan = to_dma_chan(dchan);
> +
> +       /* Has this channel already been allocated? */
> +       if (chan->desc_pool)
> +               return 1;
> +
> +       chan->desc_pool = dma_pool_create(chan->name, chan->dev,
> +                                         sizeof(struct xgene_dma_desc_sw),
> +                                         0, 0);
> +       if (!chan->desc_pool) {
> +               chan_err(chan, "Failed to allocate descriptor pool\n");
> +               return -ENOMEM;
> +       }
> +
> +       chan_dbg(chan, "Allocate descripto pool\n");
> +
> +       return 1;
> +}
> +
> +/**
> + * xgene_dma_free_desc_list - Free all descriptors in a queue
> + * @chan: X-Gene DMA channel
> + * @list: the list to free
> + *
> + * LOCKING: must hold chan->desc_lock
> + */
> +static void xgene_dma_free_desc_list(struct xgene_dma_chan *chan,
> +                                    struct list_head *list)
> +{
> +       struct xgene_dma_desc_sw *desc, *_desc;
> +
> +       list_for_each_entry_safe(desc, _desc, list, node)
> +               xgene_dma_clean_descriptor(chan, desc);
> +}
> +
> +static void xgene_dma_free_tx_desc_list(struct xgene_dma_chan *chan,
> +                                       struct list_head *list)
> +{
> +       struct xgene_dma_desc_sw *desc, *_desc;
> +
> +       list_for_each_entry_safe(desc, _desc, list, node)
> +               xgene_dma_clean_descriptor(chan, desc);
> +}
> +
> +static void xgene_dma_free_chan_resources(struct dma_chan *dchan)
> +{
> +       struct xgene_dma_chan *chan = to_dma_chan(dchan);
> +
> +       chan_dbg(chan, "Free all resources\n");
> +
> +       if (!chan->desc_pool)
> +               return;
> +
> +       spin_lock_bh(&chan->lock);
> +
> +       /* Process all running descriptor */
> +       xgene_dma_cleanup_descriptors(chan);
> +
> +       /* Clean all link descriptor queues */
> +       xgene_dma_free_desc_list(chan, &chan->ld_pending);
> +       xgene_dma_free_desc_list(chan, &chan->ld_running);
> +       xgene_dma_free_desc_list(chan, &chan->ld_completed);
> +
> +       spin_unlock_bh(&chan->lock);
> +
> +       /* Delete this channel DMA pool */
> +       dma_pool_destroy(chan->desc_pool);
> +       chan->desc_pool = NULL;
> +}
> +
> +static struct dma_async_tx_descriptor *xgene_dma_prep_memcpy(
> +       struct dma_chan *dchan, dma_addr_t dst, dma_addr_t src,
> +       size_t len, unsigned long flags)
> +{
> +       struct xgene_dma_desc_sw *first = NULL, *new;
> +       struct xgene_dma_chan *chan;
> +       size_t copy;
> +
> +       if (unlikely(!dchan || !len))
> +               return NULL;
> +
> +       chan = to_dma_chan(dchan);
> +
> +       do {
> +               /* Allocate the link descriptor from DMA pool */
> +               new = xgene_dma_alloc_descriptor(chan);
> +               if (!new)
> +                       goto fail;
> +
> +               /* Create the largest transaction possible */
> +               copy = min_t(size_t, len, XGENE_DMA_MAX_64B_DESC_BYTE_CNT);
> +
> +               /* Prepare DMA descriptor */
> +               xgene_dma_prep_cpy_desc(chan, new, dst, src, copy);
> +
> +               if (!first)
> +                       first = new;
> +
> +               new->tx.cookie = 0;
> +               async_tx_ack(&new->tx);
> +
> +               /* Update metadata */
> +               len -= copy;
> +               dst += copy;
> +               src += copy;
> +
> +               /* Insert the link descriptor to the LD ring */
> +               list_add_tail(&new->node, &first->tx_list);
> +       } while (len);
> +
> +       new->tx.flags = flags; /* client is in control of this ack */
> +       new->tx.cookie = -EBUSY;
> +       list_splice(&first->tx_list, &new->tx_list);
> +
> +       return &new->tx;
> +
> +fail:
> +       if (!first)
> +               return NULL;
> +
> +       xgene_dma_free_tx_desc_list(chan, &first->tx_list);
> +       return NULL;
> +}
> +
> +static struct dma_async_tx_descriptor *xgene_dma_prep_sg(
> +       struct dma_chan *dchan, struct scatterlist *dst_sg,
> +       u32 dst_nents, struct scatterlist *src_sg,
> +       u32 src_nents, unsigned long flags)
> +{
> +       struct xgene_dma_desc_sw *first = NULL, *new = NULL;
> +       struct xgene_dma_chan *chan;
> +       size_t dst_avail, src_avail;
> +       dma_addr_t dst, src;
> +       size_t len;
> +
> +       if (unlikely(!dchan))
> +               return NULL;
> +
> +       if (unlikely(!dst_nents || !src_nents))
> +               return NULL;
> +
> +       if (unlikely(!dst_sg || !src_sg))
> +               return NULL;
> +
> +       chan = to_dma_chan(dchan);
> +
> +       /* Get prepared for the loop */
> +       dst_avail = sg_dma_len(dst_sg);
> +       src_avail = sg_dma_len(src_sg);
> +       dst_nents--;
> +       src_nents--;
> +
> +       /* Run until we are out of scatterlist entries */
> +       while (true) {
> +               /* Create the largest transaction possible */
> +               len = min_t(size_t, src_avail, dst_avail);
> +               len = min_t(size_t, len, XGENE_DMA_MAX_64B_DESC_BYTE_CNT);
> +               if (len == 0)
> +                       goto fetch;
> +
> +               dst = sg_dma_address(dst_sg) + sg_dma_len(dst_sg) - dst_avail;
> +               src = sg_dma_address(src_sg) + sg_dma_len(src_sg) - src_avail;
> +
> +               /* Allocate the link descriptor from DMA pool */
> +               new = xgene_dma_alloc_descriptor(chan);
> +               if (!new)
> +                       goto fail;
> +
> +               /* Prepare DMA descriptor */
> +               xgene_dma_prep_cpy_desc(chan, new, dst, src, len);
> +
> +               if (!first)
> +                       first = new;
> +
> +               new->tx.cookie = 0;
> +               async_tx_ack(&new->tx);
> +
> +               /* update metadata */
> +               dst_avail -= len;
> +               src_avail -= len;
> +
> +               /* Insert the link descriptor to the LD ring */
> +               list_add_tail(&new->node, &first->tx_list);
> +
> +fetch:
> +               /* fetch the next dst scatterlist entry */
> +               if (dst_avail == 0) {
> +                       /* no more entries: we're done */
> +                       if (dst_nents == 0)
> +                               break;
> +
> +                       /* fetch the next entry: if there are no more: done */
> +                       dst_sg = sg_next(dst_sg);
> +                       if (!dst_sg)
> +                               break;
> +
> +                       dst_nents--;
> +                       dst_avail = sg_dma_len(dst_sg);
> +               }
> +
> +               /* fetch the next src scatterlist entry */
> +               if (src_avail == 0) {
> +                       /* no more entries: we're done */
> +                       if (src_nents == 0)
> +                               break;
> +
> +                       /* fetch the next entry: if there are no more: done */
> +                       src_sg = sg_next(src_sg);
> +                       if (!src_sg)
> +                               break;
> +
> +                       src_nents--;
> +                       src_avail = sg_dma_len(src_sg);
> +               }
> +       }
> +
> +       if (!new)
> +               return NULL;
> +
> +       new->tx.flags = flags; /* client is in control of this ack */
> +       new->tx.cookie = -EBUSY;
> +       list_splice(&first->tx_list, &new->tx_list);
> +
> +       return &new->tx;
> +fail:
> +       if (!first)
> +               return NULL;
> +
> +       xgene_dma_free_tx_desc_list(chan, &first->tx_list);
> +       return NULL;
> +}
> +
> +static struct dma_async_tx_descriptor *xgene_dma_prep_xor(
> +       struct dma_chan *dchan, dma_addr_t dst, dma_addr_t *src,
> +       u32 src_cnt, size_t len, unsigned long flags)
> +{
> +       struct xgene_dma_desc_sw *first = NULL, *new;
> +       struct xgene_dma_chan *chan;
> +       static u8 multi[XGENE_DMA_MAX_XOR_SRC] = {
> +                               0x01, 0x01, 0x01, 0x01, 0x01};
> +
> +       if (unlikely(!dchan || !len))
> +               return NULL;
> +
> +       chan = to_dma_chan(dchan);
> +
> +       do {
> +               /* Allocate the link descriptor from DMA pool */
> +               new = xgene_dma_alloc_descriptor(chan);
> +               if (!new)
> +                       goto fail;
> +
> +               /* Prepare xor DMA descriptor */
> +               xgene_dma_prep_xor_desc(chan, new, &dst, src,
> +                                       src_cnt, &len, multi);
> +
> +               if (!first)
> +                       first = new;
> +
> +               new->tx.cookie = 0;
> +               async_tx_ack(&new->tx);
> +
> +               /* Insert the link descriptor to the LD ring */
> +               list_add_tail(&new->node, &first->tx_list);
> +       } while (len);
> +
> +       new->tx.flags = flags; /* client is in control of this ack */
> +       new->tx.cookie = -EBUSY;
> +       list_splice(&first->tx_list, &new->tx_list);
> +
> +       return &new->tx;
> +
> +fail:
> +       if (!first)
> +               return NULL;
> +
> +       xgene_dma_free_tx_desc_list(chan, &first->tx_list);
> +       return NULL;
> +}
> +
> +static struct dma_async_tx_descriptor *xgene_dma_prep_pq(
> +       struct dma_chan *dchan, dma_addr_t *dst, dma_addr_t *src,
> +       u32 src_cnt, const u8 *scf, size_t len, unsigned long flags)
> +{
> +       struct xgene_dma_desc_sw *first = NULL, *new;
> +       struct xgene_dma_chan *chan;
> +       size_t _len = len;
> +       dma_addr_t _src[XGENE_DMA_MAX_XOR_SRC];
> +       static u8 multi[XGENE_DMA_MAX_XOR_SRC] = {0x01, 0x01, 0x01, 0x01, 0x01};
> +
> +       if (unlikely(!dchan || !len))
> +               return NULL;
> +
> +       chan = to_dma_chan(dchan);
> +
> +       /*
> +        * Save source addresses on local variable, may be we have to
> +        * prepare two descriptor to generate P and Q if both enabled
> +        * in the flags by client
> +        */
> +       memcpy(_src, src, sizeof(*src) * src_cnt);
> +
> +       if (flags & DMA_PREP_PQ_DISABLE_P)
> +               len = 0;
> +
> +       if (flags & DMA_PREP_PQ_DISABLE_Q)
> +               _len = 0;
> +
> +       do {
> +               /* Allocate the link descriptor from DMA pool */
> +               new = xgene_dma_alloc_descriptor(chan);
> +               if (!new)
> +                       goto fail;
> +
> +               if (!first)
> +                       first = new;
> +
> +               new->tx.cookie = 0;
> +               async_tx_ack(&new->tx);
> +
> +               /* Insert the link descriptor to the LD ring */
> +               list_add_tail(&new->node, &first->tx_list);
> +
> +               /*
> +                * Prepare DMA descriptor to generate P,
> +                * if DMA_PREP_PQ_DISABLE_P flag is not set
> +                */
> +               if (len) {
> +                       xgene_dma_prep_xor_desc(chan, new, &dst[0], src,
> +                                               src_cnt, &len, multi);
> +                       continue;
> +               }
> +
> +               /*
> +                * Prepare DMA descriptor to generate Q,
> +                * if DMA_PREP_PQ_DISABLE_Q flag is not set
> +                */
> +               if (_len) {
> +                       xgene_dma_prep_xor_desc(chan, new, &dst[1], _src,
> +                                               src_cnt, &_len, scf);
> +               }
> +       } while (len || _len);
> +
> +       new->tx.flags = flags; /* client is in control of this ack */
> +       new->tx.cookie = -EBUSY;
> +       list_splice(&first->tx_list, &new->tx_list);
> +
> +       return &new->tx;
> +
> +fail:
> +       if (!first)
> +               return NULL;
> +
> +       xgene_dma_free_tx_desc_list(chan, &first->tx_list);
> +       return NULL;
> +}
> +
> +static void xgene_dma_issue_pending(struct dma_chan *dchan)
> +{
> +       struct xgene_dma_chan *chan = to_dma_chan(dchan);
> +
> +       spin_lock_bh(&chan->lock);
> +       xgene_chan_xfer_ld_pending(chan);
> +       spin_unlock_bh(&chan->lock);
> +}
> +
> +static enum dma_status xgene_dma_tx_status(struct dma_chan *dchan,
> +                                          dma_cookie_t cookie,
> +                                          struct dma_tx_state *txstate)
> +{
> +       return dma_cookie_status(dchan, cookie, txstate);
> +}
> +
> +static void xgene_dma_tasklet_cb(unsigned long data)
> +{
> +       struct xgene_dma_chan *chan = (struct xgene_dma_chan *)data;
> +
> +       spin_lock_bh(&chan->lock);
> +
> +       /* Run all cleanup for descriptors which have been completed */
> +       xgene_dma_cleanup_descriptors(chan);
> +
> +       /* Re-enable DMA channel IRQ */
> +       enable_irq(chan->rx_irq);
> +
> +       spin_unlock_bh(&chan->lock);
> +}
> +
> +static irqreturn_t xgene_dma_chan_ring_isr(int irq, void *id)
> +{
> +       struct xgene_dma_chan *chan = (struct xgene_dma_chan *)id;
> +
> +       BUG_ON(!chan);
> +
> +       /*
> +        * Disable DMA channel IRQ until we process completed
> +        * descriptors
> +        */
> +       disable_irq_nosync(chan->rx_irq);
> +
> +       /*
> +        * Schedule the tasklet to handle all cleanup of the current
> +        * transaction. It will start a new transaction if there is
> +        * one pending.
> +        */
> +       tasklet_schedule(&chan->tasklet);
> +
> +       return IRQ_HANDLED;
> +}
> +
> +static irqreturn_t xgene_dma_err_isr(int irq, void *id)
> +{
> +       struct xgene_dma *pdma = (struct xgene_dma *)id;
> +       unsigned long int_mask;
> +       u32 val, i;
> +
> +       val = ioread32(pdma->csr_dma + XGENE_DMA_INT);
> +
> +       /* Clear DMA interrupts */
> +       iowrite32(val, pdma->csr_dma + XGENE_DMA_INT);
> +
> +       /* Print DMA error info */
> +       int_mask = val >> XGENE_DMA_INT_MASK_SHIFT;
> +       for_each_set_bit(i, &int_mask, ARRAY_SIZE(xgene_dma_err))
> +               dev_err(pdma->dev,
> +                       "Interrupt status 0x%08X %s\n", val, xgene_dma_err[i]);
> +
> +       return IRQ_HANDLED;
> +}
> +
> +static void xgene_dma_wr_ring_state(struct xgene_dma_ring *ring)
> +{
> +       int i;
> +
> +       iowrite32(ring->num, ring->pdma->csr_ring + XGENE_DMA_RING_STATE);
> +
> +       for (i = 0; i < XGENE_DMA_RING_NUM_CONFIG; i++)
> +               iowrite32(ring->state[i], ring->pdma->csr_ring +
> +                         XGENE_DMA_RING_STATE_WR_BASE + (i * 4));
> +}
> +
> +static void xgene_dma_clr_ring_state(struct xgene_dma_ring *ring)
> +{
> +       memset(ring->state, 0, sizeof(u32) * XGENE_DMA_RING_NUM_CONFIG);
> +       xgene_dma_wr_ring_state(ring);
> +}
> +
> +static void xgene_dma_setup_ring(struct xgene_dma_ring *ring)
> +{
> +       void *ring_cfg = ring->state;
> +       u64 addr = ring->desc_paddr;
> +       void *desc;
> +       u32 i, val;
> +
> +       ring->slots = ring->size / XGENE_DMA_RING_WQ_DESC_SIZE;
> +
> +       /* Clear DMA ring state */
> +       xgene_dma_clr_ring_state(ring);
> +
> +       /* Set DMA ring type */
> +       XGENE_DMA_RING_TYPE_SET(ring_cfg, XGENE_DMA_RING_TYPE_REGULAR);
> +
> +       if (ring->owner == XGENE_DMA_RING_OWNER_DMA) {
> +               /* Set recombination buffer and timeout */
> +               XGENE_DMA_RING_RECOMBBUF_SET(ring_cfg);
> +               XGENE_DMA_RING_RECOMTIMEOUTL_SET(ring_cfg);
> +               XGENE_DMA_RING_RECOMTIMEOUTH_SET(ring_cfg);
> +       }
> +
> +       /* Initialize DMA ring state */
> +       XGENE_DMA_RING_SELTHRSH_SET(ring_cfg);
> +       XGENE_DMA_RING_ACCEPTLERR_SET(ring_cfg);
> +       XGENE_DMA_RING_COHERENT_SET(ring_cfg);
> +       XGENE_DMA_RING_ADDRL_SET(ring_cfg, addr);
> +       XGENE_DMA_RING_ADDRH_SET(ring_cfg, addr);
> +       XGENE_DMA_RING_SIZE_SET(ring_cfg, ring->cfgsize);
> +
> +       /* Write DMA ring configurations */
> +       xgene_dma_wr_ring_state(ring);
> +
> +       /* Set DMA ring id */
> +       iowrite32(XGENE_DMA_RING_ID_SETUP(ring->id),
> +                 ring->pdma->csr_ring + XGENE_DMA_RING_ID);
> +
> +       /* Set DMA ring buffer */
> +       iowrite32(XGENE_DMA_RING_ID_BUF_SETUP(ring->num),
> +                 ring->pdma->csr_ring + XGENE_DMA_RING_ID_BUF);
> +
> +       if (ring->owner != XGENE_DMA_RING_OWNER_CPU)
> +               return;
> +
> +       /* Set empty signature to DMA Rx ring descriptors */
> +       for (i = 0; i < ring->slots; i++) {
> +               desc = &ring->desc_hw[i];
> +               XGENE_DMA_DESC_SET_EMPTY(desc);
> +       }
> +
> +       /* Enable DMA Rx ring interrupt */
> +       val = ioread32(ring->pdma->csr_ring + XGENE_DMA_RING_NE_INT_MODE);
> +       XGENE_DMA_RING_NE_INT_MODE_SET(val, ring->buf_num);
> +       iowrite32(val, ring->pdma->csr_ring + XGENE_DMA_RING_NE_INT_MODE);
> +}
> +
> +static void xgene_dma_clear_ring(struct xgene_dma_ring *ring)
> +{
> +       u32 ring_id, val;
> +
> +       if (ring->owner == XGENE_DMA_RING_OWNER_CPU) {
> +               /* Disable DMA Rx ring interrupt */
> +               val = ioread32(ring->pdma->csr_ring +
> +                              XGENE_DMA_RING_NE_INT_MODE);
> +               XGENE_DMA_RING_NE_INT_MODE_RESET(val, ring->buf_num);
> +               iowrite32(val, ring->pdma->csr_ring +
> +                         XGENE_DMA_RING_NE_INT_MODE);
> +       }
> +
> +       /* Clear DMA ring state */
> +       ring_id = XGENE_DMA_RING_ID_SETUP(ring->id);
> +       iowrite32(ring_id, ring->pdma->csr_ring + XGENE_DMA_RING_ID);
> +
> +       iowrite32(0, ring->pdma->csr_ring + XGENE_DMA_RING_ID_BUF);
> +       xgene_dma_clr_ring_state(ring);
> +}
> +
> +static void xgene_dma_set_ring_cmd(struct xgene_dma_ring *ring)
> +{
> +       ring->cmd_base = ring->pdma->csr_ring_cmd +
> +                               XGENE_DMA_RING_CMD_BASE_OFFSET((ring->num -
> +                                                         XGENE_DMA_RING_NUM));
> +
> +       ring->cmd = ring->cmd_base + XGENE_DMA_RING_CMD_OFFSET;
> +}
> +
> +static int xgene_dma_get_ring_size(struct xgene_dma_chan *chan,
> +                                  enum xgene_dma_ring_cfgsize cfgsize)
> +{
> +       int size;
> +
> +       switch (cfgsize) {
> +       case XGENE_DMA_RING_CFG_SIZE_512B:
> +               size = 0x200;
> +               break;
> +       case XGENE_DMA_RING_CFG_SIZE_2KB:
> +               size = 0x800;
> +               break;
> +       case XGENE_DMA_RING_CFG_SIZE_16KB:
> +               size = 0x4000;
> +               break;
> +       case XGENE_DMA_RING_CFG_SIZE_64KB:
> +               size = 0x10000;
> +               break;
> +       case XGENE_DMA_RING_CFG_SIZE_512KB:
> +               size = 0x80000;
> +               break;
> +       default:
> +               chan_err(chan, "Unsupported cfg ring size %d\n", cfgsize);
> +               return -EINVAL;
> +       }
> +
> +       return size;
> +}
> +
> +static void xgene_dma_delete_ring_one(struct xgene_dma_ring *ring)
> +{
> +       /* Clear DMA ring configurations */
> +       xgene_dma_clear_ring(ring);
> +
> +       /* De-allocate DMA ring descriptor */
> +       if (ring->desc_vaddr) {
> +               dma_free_coherent(ring->pdma->dev, ring->size,
> +                                 ring->desc_vaddr, ring->desc_paddr);
> +               ring->desc_vaddr = NULL;
> +       }
> +}
> +
> +static void xgene_dma_delete_chan_rings(struct xgene_dma_chan *chan)
> +{
> +       xgene_dma_delete_ring_one(&chan->rx_ring);
> +       xgene_dma_delete_ring_one(&chan->tx_ring);
> +}
> +
> +static int xgene_dma_create_ring_one(struct xgene_dma_chan *chan,
> +                                    struct xgene_dma_ring *ring,
> +                                    enum xgene_dma_ring_cfgsize cfgsize)
> +{
> +       /* Setup DMA ring descriptor variables */
> +       ring->pdma = chan->pdma;
> +       ring->cfgsize = cfgsize;
> +       ring->num = chan->pdma->ring_num++;
> +       ring->id = XGENE_DMA_RING_ID_GET(ring->owner, ring->buf_num);
> +
> +       ring->size = xgene_dma_get_ring_size(chan, cfgsize);
> +       if (ring->size <= 0)
> +               return ring->size;
> +
> +       /* Allocate memory for DMA ring descriptor */
> +       ring->desc_vaddr = dma_zalloc_coherent(chan->dev, ring->size,
> +                                              &ring->desc_paddr, GFP_KERNEL);
> +       if (!ring->desc_vaddr) {
> +               chan_err(chan, "Failed to allocate ring desc\n");
> +               return -ENOMEM;
> +       }
> +
> +       /* Configure and enable DMA ring */
> +       xgene_dma_set_ring_cmd(ring);
> +       xgene_dma_setup_ring(ring);
> +
> +       return 0;
> +}
> +
> +static int xgene_dma_create_chan_rings(struct xgene_dma_chan *chan)
> +{
> +       struct xgene_dma_ring *rx_ring = &chan->rx_ring;
> +       struct xgene_dma_ring *tx_ring = &chan->tx_ring;
> +       int ret;
> +
> +       /* Create DMA Rx ring descriptor */
> +       rx_ring->owner = XGENE_DMA_RING_OWNER_CPU;
> +       rx_ring->buf_num = XGENE_DMA_CPU_BUFNUM + chan->id;
> +
> +       ret = xgene_dma_create_ring_one(chan, rx_ring,
> +                                       XGENE_DMA_RING_CFG_SIZE_64KB);
> +       if (ret)
> +               return ret;
> +
> +       chan_dbg(chan, "Rx ring id 0x%X num %d desc 0x%p\n",
> +                rx_ring->id, rx_ring->num, rx_ring->desc_vaddr);
> +
> +       /* Create DMA Tx ring descriptor */
> +       tx_ring->owner = XGENE_DMA_RING_OWNER_DMA;
> +       tx_ring->buf_num = XGENE_DMA_BUFNUM + chan->id;
> +
> +       ret = xgene_dma_create_ring_one(chan, tx_ring,
> +                                       XGENE_DMA_RING_CFG_SIZE_64KB);
> +       if (ret) {
> +               xgene_dma_delete_ring_one(rx_ring);
> +               return ret;
> +       }
> +
> +       tx_ring->dst_ring_num = XGENE_DMA_RING_DST_ID(rx_ring->num);
> +
> +       chan_dbg(chan,
> +                "Tx ring id 0x%X num %d desc 0x%p\n",
> +                tx_ring->id, tx_ring->num, tx_ring->desc_vaddr);
> +
> +       /* Set the max outstanding request possible to this channel */
> +       chan->max_outstanding = rx_ring->slots;
> +
> +       return ret;
> +}
> +
> +static int xgene_dma_init_rings(struct xgene_dma *pdma)
> +{
> +       int ret, i, j;
> +
> +       for (i = 0; i < XGENE_DMA_MAX_CHANNEL; i++) {
> +               ret = xgene_dma_create_chan_rings(&pdma->chan[i]);
> +               if (ret) {
> +                       for (j = 0; j < i; j++)
> +                               xgene_dma_delete_chan_rings(&pdma->chan[j]);
> +                       return ret;
> +               }
> +       }
> +
> +       return ret;
> +}
> +
> +static void xgene_dma_enable(struct xgene_dma *pdma)
> +{
> +       u32 val;
> +
> +       /* Configure and enable DMA engine */
> +       val = ioread32(pdma->csr_dma + XGENE_DMA_GCR);
> +       XGENE_DMA_CH_SETUP(val);
> +       XGENE_DMA_ENABLE(val);
> +       iowrite32(val, pdma->csr_dma + XGENE_DMA_GCR);
> +}
> +
> +static void xgene_dma_disable(struct xgene_dma *pdma)
> +{
> +       u32 val;
> +
> +       val = ioread32(pdma->csr_dma + XGENE_DMA_GCR);
> +       XGENE_DMA_DISABLE(val);
> +       iowrite32(val, pdma->csr_dma + XGENE_DMA_GCR);
> +}
> +
> +static void xgene_dma_mask_interrupts(struct xgene_dma *pdma)
> +{
> +       /*
> +        * Mask DMA ring overflow, underflow and
> +        * AXI write/read error interrupts
> +        */
> +       iowrite32(XGENE_DMA_INT_ALL_MASK,
> +                 pdma->csr_dma + XGENE_DMA_RING_INT0_MASK);
> +       iowrite32(XGENE_DMA_INT_ALL_MASK,
> +                 pdma->csr_dma + XGENE_DMA_RING_INT1_MASK);
> +       iowrite32(XGENE_DMA_INT_ALL_MASK,
> +                 pdma->csr_dma + XGENE_DMA_RING_INT2_MASK);
> +       iowrite32(XGENE_DMA_INT_ALL_MASK,
> +                 pdma->csr_dma + XGENE_DMA_RING_INT3_MASK);
> +       iowrite32(XGENE_DMA_INT_ALL_MASK,
> +                 pdma->csr_dma + XGENE_DMA_RING_INT4_MASK);
> +
> +       /* Mask DMA error interrupts */
> +       iowrite32(XGENE_DMA_INT_ALL_MASK, pdma->csr_dma + XGENE_DMA_INT_MASK);
> +}
> +
> +static void xgene_dma_unmask_interrupts(struct xgene_dma *pdma)
> +{
> +       /*
> +        * Unmask DMA ring overflow, underflow and
> +        * AXI write/read error interrupts
> +        */
> +       iowrite32(XGENE_DMA_INT_ALL_UNMASK,
> +                 pdma->csr_dma + XGENE_DMA_RING_INT0_MASK);
> +       iowrite32(XGENE_DMA_INT_ALL_UNMASK,
> +                 pdma->csr_dma + XGENE_DMA_RING_INT1_MASK);
> +       iowrite32(XGENE_DMA_INT_ALL_UNMASK,
> +                 pdma->csr_dma + XGENE_DMA_RING_INT2_MASK);
> +       iowrite32(XGENE_DMA_INT_ALL_UNMASK,
> +                 pdma->csr_dma + XGENE_DMA_RING_INT3_MASK);
> +       iowrite32(XGENE_DMA_INT_ALL_UNMASK,
> +                 pdma->csr_dma + XGENE_DMA_RING_INT4_MASK);
> +
> +       /* Unmask DMA error interrupts */
> +       iowrite32(XGENE_DMA_INT_ALL_UNMASK,
> +                 pdma->csr_dma + XGENE_DMA_INT_MASK);
> +}
> +
> +static void xgene_dma_init_hw(struct xgene_dma *pdma)
> +{
> +       u32 val;
> +
> +       /* Associate DMA ring to corresponding ring HW */
> +       iowrite32(XGENE_DMA_ASSOC_RING_MNGR1,
> +                 pdma->csr_dma + XGENE_DMA_CFG_RING_WQ_ASSOC);
> +
> +       /* Configure RAID6 polynomial control setting */
> +       if (is_pq_enabled(pdma))
> +               iowrite32(XGENE_DMA_RAID6_MULTI_CTRL(0x1D),
> +                         pdma->csr_dma + XGENE_DMA_RAID6_CONT);
> +       else
> +               dev_info(pdma->dev, "PQ is disabled in HW\n");
> +
> +       xgene_dma_enable(pdma);
> +       xgene_dma_unmask_interrupts(pdma);
> +
> +       /* Get DMA id and version info */
> +       val = ioread32(pdma->csr_dma + XGENE_DMA_IPBRR);
> +
> +       /* DMA device info */
> +       dev_info(pdma->dev,
> +                "X-Gene DMA v%d.%02d.%02d driver registered %d channels",
> +                XGENE_DMA_REV_NO_RD(val), XGENE_DMA_BUS_ID_RD(val),
> +                XGENE_DMA_DEV_ID_RD(val), XGENE_DMA_MAX_CHANNEL);
> +}
> +
> +int xgene_dma_init_ring_mngr(struct xgene_dma *pdma)
> +{
> +       if (ioread32(pdma->csr_ring + XGENE_DMA_RING_CLKEN) &&
> +           (!ioread32(pdma->csr_ring + XGENE_DMA_RING_SRST)))
> +               return 0;
> +
> +       iowrite32(0x3, pdma->csr_ring + XGENE_DMA_RING_CLKEN);
> +       iowrite32(0x0, pdma->csr_ring + XGENE_DMA_RING_SRST);
> +
> +       /* Bring up memory */
> +       iowrite32(0x0, pdma->csr_ring + XGENE_DMA_RING_MEM_RAM_SHUTDOWN);
> +
> +       /* Force a barrier */
> +       ioread32(pdma->csr_ring + XGENE_DMA_RING_MEM_RAM_SHUTDOWN);
> +
> +       /* reset may take up to 1ms */
> +       usleep_range(1000, 1100);
> +
> +       if (ioread32(pdma->csr_ring + XGENE_DMA_RING_BLK_MEM_RDY)
> +               != XGENE_DMA_RING_BLK_MEM_RDY_VAL) {
> +               dev_err(pdma->dev,
> +                       "Failed to release ring mngr memory from shutdown\n");
> +               return -ENODEV;
> +       }
> +
> +       /* program threshold set 1 and all hysteresis */
> +       iowrite32(XGENE_DMA_RING_THRESLD0_SET1_VAL,
> +                 pdma->csr_ring + XGENE_DMA_RING_THRESLD0_SET1);
> +       iowrite32(XGENE_DMA_RING_THRESLD1_SET1_VAL,
> +                 pdma->csr_ring + XGENE_DMA_RING_THRESLD1_SET1);
> +       iowrite32(XGENE_DMA_RING_HYSTERESIS_VAL,
> +                 pdma->csr_ring + XGENE_DMA_RING_HYSTERESIS);
> +
> +       /* Enable QPcore and assign error queue */
> +       iowrite32(XGENE_DMA_RING_ENABLE,
> +                 pdma->csr_ring + XGENE_DMA_RING_CONFIG);
> +
> +       return 0;
> +}
> +
> +static int xgene_dma_init_mem(struct xgene_dma *pdma)
> +{
> +       int ret;
> +
> +       ret = xgene_dma_init_ring_mngr(pdma);
> +       if (ret)
> +               return ret;
> +
> +       /* Bring up memory */
> +       iowrite32(0x0, pdma->csr_dma + XGENE_DMA_MEM_RAM_SHUTDOWN);
> +
> +       /* Force a barrier */
> +       ioread32(pdma->csr_dma + XGENE_DMA_MEM_RAM_SHUTDOWN);
> +
> +       /* reset may take up to 1ms */
> +       usleep_range(1000, 1100);
> +
> +       if (ioread32(pdma->csr_dma + XGENE_DMA_BLK_MEM_RDY)
> +               != XGENE_DMA_BLK_MEM_RDY_VAL) {
> +               dev_err(pdma->dev,
> +                       "Failed to release DMA memory from shutdown\n");
> +               return -ENODEV;
> +       }
> +
> +       return 0;
> +}
> +
> +static int xgene_dma_request_irqs(struct xgene_dma *pdma)
> +{
> +       struct xgene_dma_chan *chan;
> +       int ret, i, j;
> +
> +       /* Register DMA error irq */
> +       ret = devm_request_irq(pdma->dev, pdma->err_irq, xgene_dma_err_isr,
> +                              0, "dma_error", pdma);
> +       if (ret) {
> +               dev_err(pdma->dev,
> +                       "Failed to register error IRQ %d\n", pdma->err_irq);
> +               return ret;
> +       }
> +
> +       /* Register DMA channel rx irq */
> +       for (i = 0; i < XGENE_DMA_MAX_CHANNEL; i++) {
> +               chan = &pdma->chan[i];
> +               ret = devm_request_irq(chan->dev, chan->rx_irq,
> +                                      xgene_dma_chan_ring_isr,
> +                                      0, chan->name, chan);
> +               if (ret) {
> +                       chan_err(chan, "Failed to register Rx IRQ %d\n",
> +                                chan->rx_irq);
> +                       devm_free_irq(pdma->dev, pdma->err_irq, pdma);
> +
> +                       for (j = 0; j < i; j++) {
> +                               chan = &pdma->chan[i];
> +                               devm_free_irq(chan->dev, chan->rx_irq, chan);
> +                       }
> +
> +                       return ret;
> +               }
> +       }
> +
> +       return 0;
> +}
> +
> +static void xgene_dma_free_irqs(struct xgene_dma *pdma)
> +{
> +       struct xgene_dma_chan *chan;
> +       int i;
> +
> +       /* Free DMA device error irq */
> +       devm_free_irq(pdma->dev, pdma->err_irq, pdma);
> +
> +       for (i = 0; i < XGENE_DMA_MAX_CHANNEL; i++) {
> +               chan = &pdma->chan[i];
> +               devm_free_irq(chan->dev, chan->rx_irq, chan);
> +       }
> +}
> +
> +static void xgene_dma_set_caps(struct xgene_dma_chan *chan,
> +                              struct dma_device *dma_dev)
> +{
> +       /* Initialize DMA device capability mask */
> +       dma_cap_zero(dma_dev->cap_mask);
> +
> +       /* Set DMA device capability */
> +       dma_cap_set(DMA_MEMCPY, dma_dev->cap_mask);
> +       dma_cap_set(DMA_SG, dma_dev->cap_mask);
> +
> +       /* Basically here, the X-Gene SoC DMA engine channel 0 supports XOR
> +        * and channel 1 supports XOR, PQ both. First thing here is we have
> +        * mechanism in hw to enable/disable PQ/XOR supports on channel 1,
> +        * we can make sure this by reading SoC Efuse register.
> +        * Second thing, we have hw errata that if we run channel 0 and
> +        * channel 1 simultaneously with executing XOR and PQ request,
> +        * suddenly DMA engine hangs, So here we enable XOR on channel 0 only
> +        * if XOR and PQ supports on channel 1 is disabled.
> +        */
> +       if ((chan->id == XGENE_DMA_PQ_CHANNEL) &&
> +           is_pq_enabled(chan->pdma)) {
> +               dma_cap_set(DMA_PQ, dma_dev->cap_mask);
> +               dma_cap_set(DMA_XOR, dma_dev->cap_mask);
> +       } else if ((chan->id == XGENE_DMA_XOR_CHANNEL) &&
> +                  !is_pq_enabled(chan->pdma)) {
> +               dma_cap_set(DMA_XOR, dma_dev->cap_mask);
> +       }
> +
> +       /* Set base and prep routines */
> +       dma_dev->dev = chan->dev;
> +       dma_dev->device_alloc_chan_resources = xgene_dma_alloc_chan_resources;
> +       dma_dev->device_free_chan_resources = xgene_dma_free_chan_resources;
> +       dma_dev->device_issue_pending = xgene_dma_issue_pending;
> +       dma_dev->device_tx_status = xgene_dma_tx_status;
> +       dma_dev->device_prep_dma_memcpy = xgene_dma_prep_memcpy;
> +       dma_dev->device_prep_dma_sg = xgene_dma_prep_sg;
> +
> +       if (dma_has_cap(DMA_XOR, dma_dev->cap_mask)) {
> +               dma_dev->device_prep_dma_xor = xgene_dma_prep_xor;
> +               dma_dev->max_xor = XGENE_DMA_MAX_XOR_SRC;
> +               dma_dev->xor_align = XGENE_DMA_XOR_ALIGNMENT;
> +       }
> +
> +       if (dma_has_cap(DMA_PQ, dma_dev->cap_mask)) {
> +               dma_dev->device_prep_dma_pq = xgene_dma_prep_pq;
> +               dma_dev->max_pq = XGENE_DMA_MAX_XOR_SRC;
> +               dma_dev->pq_align = XGENE_DMA_XOR_ALIGNMENT;
> +       }
> +}
> +
> +static int xgene_dma_async_register(struct xgene_dma *pdma, int id)
> +{
> +       struct xgene_dma_chan *chan = &pdma->chan[id];
> +       struct dma_device *dma_dev = &pdma->dma_dev[id];
> +       int ret;
> +
> +       chan->dma_chan.device = dma_dev;
> +
> +       spin_lock_init(&chan->lock);
> +       INIT_LIST_HEAD(&chan->ld_pending);
> +       INIT_LIST_HEAD(&chan->ld_running);
> +       INIT_LIST_HEAD(&chan->ld_completed);
> +       tasklet_init(&chan->tasklet, xgene_dma_tasklet_cb,
> +                    (unsigned long)chan);
> +
> +       chan->pending = 0;
> +       chan->desc_pool = NULL;
> +       dma_cookie_init(&chan->dma_chan);
> +
> +       /* Setup dma device capabilities and prep routines */
> +       xgene_dma_set_caps(chan, dma_dev);
> +
> +       /* Initialize DMA device list head */
> +       INIT_LIST_HEAD(&dma_dev->channels);
> +       list_add_tail(&chan->dma_chan.device_node, &dma_dev->channels);
> +
> +       /* Register with Linux async DMA framework*/
> +       ret = dma_async_device_register(dma_dev);
> +       if (ret) {
> +               chan_err(chan, "Failed to register async device %d", ret);
> +               tasklet_kill(&chan->tasklet);
> +
> +               return ret;
> +       }
> +
> +       /* DMA capability info */
> +       dev_info(pdma->dev,
> +                "%s: CAPABILITY ( %s%s%s%s)\n", dma_chan_name(&chan->dma_chan),
> +                dma_has_cap(DMA_MEMCPY, dma_dev->cap_mask) ? "MEMCPY " : "",
> +                dma_has_cap(DMA_SG, dma_dev->cap_mask) ? "SGCPY " : "",
> +                dma_has_cap(DMA_XOR, dma_dev->cap_mask) ? "XOR " : "",
> +                dma_has_cap(DMA_PQ, dma_dev->cap_mask) ? "PQ " : "");
> +
> +       return 0;
> +}
> +
> +static int xgene_dma_init_async(struct xgene_dma *pdma)
> +{
> +       int ret, i, j;
> +
> +       for (i = 0; i < XGENE_DMA_MAX_CHANNEL ; i++) {
> +               ret = xgene_dma_async_register(pdma, i);
> +               if (ret) {
> +                       for (j = 0; j < i; j++) {
> +                               dma_async_device_unregister(&pdma->dma_dev[j]);
> +                               tasklet_kill(&pdma->chan[j].tasklet);
> +                       }
> +
> +                       return ret;
> +               }
> +       }
> +
> +       return ret;
> +}
> +
> +static void xgene_dma_async_unregister(struct xgene_dma *pdma)
> +{
> +       int i;
> +
> +       for (i = 0; i < XGENE_DMA_MAX_CHANNEL; i++)
> +               dma_async_device_unregister(&pdma->dma_dev[i]);
> +}
> +
> +static void xgene_dma_init_channels(struct xgene_dma *pdma)
> +{
> +       struct xgene_dma_chan *chan;
> +       int i;
> +
> +       pdma->ring_num = XGENE_DMA_RING_NUM;
> +
> +       for (i = 0; i < XGENE_DMA_MAX_CHANNEL; i++) {
> +               chan = &pdma->chan[i];
> +               chan->dev = pdma->dev;
> +               chan->pdma = pdma;
> +               chan->id = i;
> +               sprintf(chan->name, "dmachan%d", chan->id);
> +       }
> +}
> +
> +static int xgene_dma_get_resources(struct platform_device *pdev,
> +                                  struct xgene_dma *pdma)
> +{
> +       struct resource *res;
> +       int irq, i;
> +
> +       /* Get DMA csr region */
> +       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +       if (!res) {
> +               dev_err(&pdev->dev, "Failed to get csr region\n");
> +               return -ENXIO;
> +       }
> +
> +       pdma->csr_dma = devm_ioremap(&pdev->dev, res->start,
> +                                    resource_size(res));
> +       if (IS_ERR(pdma->csr_dma)) {
> +               dev_err(&pdev->dev, "Failed to ioremap csr region");
> +               return PTR_ERR(pdma->csr_dma);
> +       }
> +
> +       /* Get DMA ring csr region */
> +       res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
> +       if (!res) {
> +               dev_err(&pdev->dev, "Failed to get ring csr region\n");
> +               return -ENXIO;
> +       }
> +
> +       pdma->csr_ring =  devm_ioremap(&pdev->dev, res->start,
> +                                      resource_size(res));
> +       if (IS_ERR(pdma->csr_ring)) {
> +               dev_err(&pdev->dev, "Failed to ioremap ring csr region");
> +               return PTR_ERR(pdma->csr_ring);
> +       }
> +
> +       /* Get DMA ring cmd csr region */
> +       res = platform_get_resource(pdev, IORESOURCE_MEM, 2);
> +       if (!res) {
> +               dev_err(&pdev->dev, "Failed to get ring cmd csr region\n");
> +               return -ENXIO;
> +       }
> +
> +       pdma->csr_ring_cmd = devm_ioremap(&pdev->dev, res->start,
> +                                         resource_size(res));
> +       if (IS_ERR(pdma->csr_ring_cmd)) {
> +               dev_err(&pdev->dev, "Failed to ioremap ring cmd csr region");
> +               return PTR_ERR(pdma->csr_ring_cmd);
> +       }
> +
> +       /* Get efuse csr region */
> +       res = platform_get_resource(pdev, IORESOURCE_MEM, 3);
> +       if (!res) {
> +               dev_err(&pdev->dev, "Failed to get efuse csr region\n");
> +               return -ENXIO;
> +       }
> +
> +       pdma->csr_efuse = devm_ioremap(&pdev->dev, res->start,
> +                                      resource_size(res));
> +       if (IS_ERR(pdma->csr_efuse)) {
> +               dev_err(&pdev->dev, "Failed to ioremap efuse csr region");
> +               return PTR_ERR(pdma->csr_efuse);
> +       }
> +
> +       /* Get DMA error interrupt */
> +       irq = platform_get_irq(pdev, 0);
> +       if (irq <= 0) {
> +               dev_err(&pdev->dev, "Failed to get Error IRQ\n");
> +               return -ENXIO;
> +       }
> +
> +       pdma->err_irq = irq;
> +
> +       /* Get DMA Rx ring descriptor interrupts for all DMA channels */
> +       for (i = 1; i <= XGENE_DMA_MAX_CHANNEL; i++) {
> +               irq = platform_get_irq(pdev, i);
> +               if (irq <= 0) {
> +                       dev_err(&pdev->dev, "Failed to get Rx IRQ\n");
> +                       return -ENXIO;
> +               }
> +
> +               pdma->chan[i - 1].rx_irq = irq;
> +       }
> +
> +       return 0;
> +}
> +
> +static int xgene_dma_probe(struct platform_device *pdev)
> +{
> +       struct xgene_dma *pdma;
> +       int ret, i;
> +
> +       pdma = devm_kzalloc(&pdev->dev, sizeof(*pdma), GFP_KERNEL);
> +       if (!pdma)
> +               return -ENOMEM;
> +
> +       pdma->dev = &pdev->dev;
> +       platform_set_drvdata(pdev, pdma);
> +
> +       ret = xgene_dma_get_resources(pdev, pdma);
> +       if (ret)
> +               return ret;
> +
> +       pdma->clk = devm_clk_get(&pdev->dev, NULL);
> +       if (IS_ERR(pdma->clk)) {
> +               dev_err(&pdev->dev, "Failed to get clk\n");
> +               return PTR_ERR(pdma->clk);
> +       }
> +
> +       /* Enable clk before accessing registers */
> +       ret = clk_prepare_enable(pdma->clk);
> +       if (ret) {
> +               dev_err(&pdev->dev, "Failed to enable clk %d\n", ret);
> +               return ret;
> +       }
> +
> +       /* Remove DMA RAM out of shutdown */
> +       ret = xgene_dma_init_mem(pdma);
> +       if (ret)
> +               goto err_clk_enable;
> +
> +       ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(42));
> +       if (ret) {
> +               dev_err(&pdev->dev, "No usable DMA configuration\n");
> +               goto err_dma_mask;
> +       }
> +
> +       /* Initialize DMA channels software state */
> +       xgene_dma_init_channels(pdma);
> +
> +       /* Configue DMA rings */
> +       ret = xgene_dma_init_rings(pdma);
> +       if (ret)
> +               goto err_clk_enable;
> +
> +       ret = xgene_dma_request_irqs(pdma);
> +       if (ret)
> +               goto err_request_irq;
> +
> +       /* Configure and enable DMA engine */
> +       xgene_dma_init_hw(pdma);
> +
> +       /* Register DMA device with linux async framework */
> +       ret = xgene_dma_init_async(pdma);
> +       if (ret)
> +               goto err_async_init;
> +
> +       return 0;
> +
> +err_async_init:
> +       xgene_dma_free_irqs(pdma);
> +
> +err_request_irq:
> +       for (i = 0; i < XGENE_DMA_MAX_CHANNEL; i++)
> +               xgene_dma_delete_chan_rings(&pdma->chan[i]);
> +
> +err_dma_mask:
> +err_clk_enable:
> +       clk_disable_unprepare(pdma->clk);
> +
> +       return ret;
> +}
> +
> +static int xgene_dma_remove(struct platform_device *pdev)
> +{
> +       struct xgene_dma *pdma = platform_get_drvdata(pdev);
> +       struct xgene_dma_chan *chan;
> +       int i;
> +
> +       xgene_dma_async_unregister(pdma);
> +
> +       /* Mask interrupts and disable DMA engine */
> +       xgene_dma_mask_interrupts(pdma);
> +       xgene_dma_disable(pdma);
> +       xgene_dma_free_irqs(pdma);
> +
> +       for (i = 0; i < XGENE_DMA_MAX_CHANNEL; i++) {
> +               chan = &pdma->chan[i];
> +               tasklet_kill(&chan->tasklet);
> +               xgene_dma_delete_chan_rings(chan);
> +       }
> +
> +       clk_disable_unprepare(pdma->clk);
> +
> +       return 0;
> +}
> +
> +static const struct of_device_id xgene_dma_of_match_ptr[] = {
> +       {.compatible = "apm,xgene-storm-dma",},
> +       {},
> +};
> +MODULE_DEVICE_TABLE(of, xgene_dma_of_match_ptr);
> +
> +static struct platform_driver xgene_dma_driver = {
> +       .probe = xgene_dma_probe,
> +       .remove = xgene_dma_remove,
> +       .driver = {
> +               .name = "X-Gene-DMA",
> +               .owner = THIS_MODULE,
> +               .of_match_table = xgene_dma_of_match_ptr,
> +       },
> +};
> +
> +module_platform_driver(xgene_dma_driver);
> +
> +MODULE_DESCRIPTION("APM X-Gene SoC DMA driver");
> +MODULE_AUTHOR("Rameshwar Prasad Sahu <[e-mail]>");
> +MODULE_AUTHOR("Loc Ho <[e-mail]>");
> +MODULE_LICENSE("GPL");
> +MODULE_VERSION("1.0");
> --
> 1.8.2.1
>


Any comments on above patch....
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Rameshwar Prasad Sahu March 23, 2015, 11:07 a.m. UTC | #2

Hi Vinod,

On Thu, Mar 19, 2015 at 1:47 PM, Rameshwar Sahu <[e-mail]> wrote:
> Hi Vinod,
>
> On Wed, Mar 18, 2015 at 7:17 PM, Rameshwar Prasad Sahu <[e-mail]> wrote:
>> This patch implements the APM X-Gene SoC DMA engine driver. The APM X-Gene
>> SoC DMA engine consists of 4 DMA channels for performing DMA operations.
>> These DMA operations include memory copy, scatter-gather memory copy,
>> raid5 xor, and raid6 p+q offloading.
>>
>> Signed-off-by: Rameshwar Prasad Sahu <[e-mail]>
>> Signed-off-by: Loc Ho <[e-mail]>
>> ---
>>  drivers/dma/Kconfig     |    8 +
>>  drivers/dma/Makefile    |    1 +
>>  drivers/dma/xgene-dma.c | 2090 +++++++++++++++++++++++++++++++++++++++++++++++
>>  3 files changed, 2099 insertions(+)
>>  create mode 100755 drivers/dma/xgene-dma.c
>>
>> diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
>> index a874b6e..a271346 100644
>> --- a/drivers/dma/Kconfig
>> +++ b/drivers/dma/Kconfig
>> @@ -425,6 +425,14 @@ config IMG_MDC_DMA
>>         help
>>           Enable support for the IMG multi-threaded DMA controller (MDC).
>>
>> +config XGENE_DMA
>> +       tristate "APM X-Gene DMA support"
>> +       select DMA_ENGINE
>> +       select DMA_ENGINE_RAID
>> +       select ASYNC_TX_ENABLE_CHANNEL_SWITCH
>> +       help
>> +         Enable support for the APM X-Gene SoC DMA engine.
>> +
>>  config DMA_ENGINE
>>         bool
>>
>> diff --git a/drivers/dma/Makefile b/drivers/dma/Makefile
>> index f915f61..06c1576 100644
>> --- a/drivers/dma/Makefile
>> +++ b/drivers/dma/Makefile
>> @@ -51,3 +51,4 @@ obj-$(CONFIG_INTEL_MIC_X100_DMA) += mic_x100_dma.o
>>  obj-$(CONFIG_NBPFAXI_DMA) += nbpfaxi.o
>>  obj-$(CONFIG_DMA_SUN6I) += sun6i-dma.o
>>  obj-$(CONFIG_IMG_MDC_DMA) += img-mdc-dma.o
>> +obj-$(CONFIG_XGENE_DMA) += xgene-dma.o
>> diff --git a/drivers/dma/xgene-dma.c b/drivers/dma/xgene-dma.c
>> new file mode 100755
>> index 0000000..2383528
>> --- /dev/null
>> +++ b/drivers/dma/xgene-dma.c
>> @@ -0,0 +1,2090 @@
>> +/*
>> + * Applied Micro X-Gene SoC DMA engine Driver
>> + *
>> + * Copyright (c) 2015, Applied Micro Circuits Corporation
>> + * Authors: Rameshwar Prasad Sahu <[e-mail]>
>> + *         Loc Ho <[e-mail]>
>> + *
>> + * This program is free software; you can redistribute  it and/or modify it
>> + * under  the terms of  the GNU General  Public License as published by the
>> + * Free Software Foundation;  either version 2 of the  License, or (at your
>> + * option) any later version.
>> + *
>> + * This program is distributed in the hope that it will be useful,
>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
>> + * GNU General Public License for more details.
>> + *
>> + * You should have received a copy of the GNU General Public License
>> + * along with this program.  If not, see <http://www.gnu.org/licenses/>.
>> + *
>> + * NOTE: PM support is currently not available.
>> + */
>> +
>> +#include <linux/clk.h>
>> +#include <linux/delay.h>
>> +#include <linux/dma-mapping.h>
>> +#include <linux/dmaengine.h>
>> +#include <linux/dmapool.h>
>> +#include <linux/interrupt.h>
>> +#include <linux/io.h>
>> +#include <linux/module.h>
>> +#include <linux/of_device.h>
>> +
>> +#include "dmaengine.h"
>> +
>> +/* X-Gene DMA ring csr registers and bit definations */
>> +#define XGENE_DMA_RING_CONFIG                  0x04
>> +#define XGENE_DMA_RING_ENABLE                  BIT(31)
>> +#define XGENE_DMA_RING_ID                      0x08
>> +#define XGENE_DMA_RING_ID_SETUP(v)             ((v) | BIT(31))
>> +#define XGENE_DMA_RING_ID_BUF                  0x0C
>> +#define XGENE_DMA_RING_ID_BUF_SETUP(v)         (((v) << 9) | BIT(21))
>> +#define XGENE_DMA_RING_THRESLD0_SET1           0x30
>> +#define XGENE_DMA_RING_THRESLD0_SET1_VAL       0X64
>> +#define XGENE_DMA_RING_THRESLD1_SET1           0x34
>> +#define XGENE_DMA_RING_THRESLD1_SET1_VAL       0xC8
>> +#define XGENE_DMA_RING_HYSTERESIS              0x68
>> +#define XGENE_DMA_RING_HYSTERESIS_VAL          0xFFFFFFFF
>> +#define XGENE_DMA_RING_STATE                   0x6C
>> +#define XGENE_DMA_RING_STATE_WR_BASE           0x70
>> +#define XGENE_DMA_RING_NE_INT_MODE             0x017C
>> +#define XGENE_DMA_RING_NE_INT_MODE_SET(m, v)   \
>> +       ((m) = ((m) & ~BIT(31 - (v))) | BIT(31 - (v)))
>> +#define XGENE_DMA_RING_NE_INT_MODE_RESET(m, v) \
>> +       ((m) &= (~BIT(31 - (v))))
>> +#define XGENE_DMA_RING_CLKEN                   0xC208
>> +#define XGENE_DMA_RING_SRST                    0xC200
>> +#define XGENE_DMA_RING_MEM_RAM_SHUTDOWN                0xD070
>> +#define XGENE_DMA_RING_BLK_MEM_RDY             0xD074
>> +#define XGENE_DMA_RING_BLK_MEM_RDY_VAL         0xFFFFFFFF
>> +#define XGENE_DMA_RING_DESC_CNT(v)             (((v) & 0x0001FFFE) >> 1)
>> +#define XGENE_DMA_RING_ID_GET(owner, num)      (((owner) << 6) | (num))
>> +#define XGENE_DMA_RING_DST_ID(v)               ((1 << 10) | (v))
>> +#define XGENE_DMA_RING_CMD_OFFSET              0x2C
>> +#define XGENE_DMA_RING_CMD_BASE_OFFSET(v)      ((v) << 6)
>> +#define XGENE_DMA_RING_COHERENT_SET(m)         \
>> +       (((u32 *)(m))[2] |= BIT(4))
>> +#define XGENE_DMA_RING_ADDRL_SET(m, v)         \
>> +       (((u32 *)(m))[2] |= (((v) >> 8) << 5))
>> +#define XGENE_DMA_RING_ADDRH_SET(m, v)         \
>> +       (((u32 *)(m))[3] |= ((v) >> 35))
>> +#define XGENE_DMA_RING_ACCEPTLERR_SET(m)       \
>> +       (((u32 *)(m))[3] |= BIT(19))
>> +#define XGENE_DMA_RING_SIZE_SET(m, v)          \
>> +       (((u32 *)(m))[3] |= ((v) << 23))
>> +#define XGENE_DMA_RING_RECOMBBUF_SET(m)                \
>> +       (((u32 *)(m))[3] |= BIT(27))
>> +#define XGENE_DMA_RING_RECOMTIMEOUTL_SET(m)    \
>> +       (((u32 *)(m))[3] |= (0x7 << 28))
>> +#define XGENE_DMA_RING_RECOMTIMEOUTH_SET(m)    \
>> +       (((u32 *)(m))[4] |= 0x3)
>> +#define XGENE_DMA_RING_SELTHRSH_SET(m)         \
>> +       (((u32 *)(m))[4] |= BIT(3))
>> +#define XGENE_DMA_RING_TYPE_SET(m, v)          \
>> +       (((u32 *)(m))[4] |= ((v) << 19))
>> +
>> +/* X-Gene DMA device csr registers and bit definitions */
>> +#define XGENE_DMA_IPBRR                                0x0
>> +#define XGENE_DMA_DEV_ID_RD(v)                 ((v) & 0x00000FFF)
>> +#define XGENE_DMA_BUS_ID_RD(v)                 (((v) >> 12) & 3)
>> +#define XGENE_DMA_REV_NO_RD(v)                 (((v) >> 14) & 3)
>> +#define XGENE_DMA_GCR                          0x10
>> +#define XGENE_DMA_CH_SETUP(v)                  \
>> +       ((v) = ((v) & ~0x000FFFFF) | 0x000AAFFF)
>> +#define XGENE_DMA_ENABLE(v)                    ((v) |= BIT(31))
>> +#define XGENE_DMA_DISABLE(v)                   ((v) &= ~BIT(31))
>> +#define XGENE_DMA_RAID6_CONT                   0x14
>> +#define XGENE_DMA_RAID6_MULTI_CTRL(v)          ((v) << 24)
>> +#define XGENE_DMA_INT                          0x70
>> +#define XGENE_DMA_INT_MASK                     0x74
>> +#define XGENE_DMA_INT_ALL_MASK                 0xFFFFFFFF
>> +#define XGENE_DMA_INT_ALL_UNMASK               0x0
>> +#define XGENE_DMA_INT_MASK_SHIFT               0x14
>> +#define XGENE_DMA_RING_INT0_MASK               0x90A0
>> +#define XGENE_DMA_RING_INT1_MASK               0x90A8
>> +#define XGENE_DMA_RING_INT2_MASK               0x90B0
>> +#define XGENE_DMA_RING_INT3_MASK               0x90B8
>> +#define XGENE_DMA_RING_INT4_MASK               0x90C0
>> +#define XGENE_DMA_CFG_RING_WQ_ASSOC            0x90E0
>> +#define XGENE_DMA_ASSOC_RING_MNGR1             0xFFFFFFFF
>> +#define XGENE_DMA_MEM_RAM_SHUTDOWN             0xD070
>> +#define XGENE_DMA_BLK_MEM_RDY                  0xD074
>> +#define XGENE_DMA_BLK_MEM_RDY_VAL              0xFFFFFFFF
>> +
>> +/* X-Gene SoC EFUSE csr register and bit defination */
>> +#define XGENE_SOC_JTAG1_SHADOW                 0x18
>> +#define XGENE_DMA_PQ_DISABLE_MASK              BIT(13)
>> +
>> +/* X-Gene DMA Descriptor format */
>> +#define XGENE_DMA_DESC_NV_BIT                  BIT_ULL(50)
>> +#define XGENE_DMA_DESC_IN_BIT                  BIT_ULL(55)
>> +#define XGENE_DMA_DESC_C_BIT                   BIT_ULL(63)
>> +#define XGENE_DMA_DESC_DR_BIT                  BIT_ULL(61)
>> +#define XGENE_DMA_DESC_ELERR_POS               46
>> +#define XGENE_DMA_DESC_RTYPE_POS               56
>> +#define XGENE_DMA_DESC_LERR_POS                        60
>> +#define XGENE_DMA_DESC_FLYBY_POS               4
>> +#define XGENE_DMA_DESC_BUFLEN_POS              48
>> +#define XGENE_DMA_DESC_HOENQ_NUM_POS           48
>> +
>> +#define XGENE_DMA_DESC_NV_SET(m)               \
>> +       (((u64 *)(m))[0] |= XGENE_DMA_DESC_NV_BIT)
>> +#define XGENE_DMA_DESC_IN_SET(m)               \
>> +       (((u64 *)(m))[0] |= XGENE_DMA_DESC_IN_BIT)
>> +#define XGENE_DMA_DESC_RTYPE_SET(m, v)         \
>> +       (((u64 *)(m))[0] |= ((u64)(v) << XGENE_DMA_DESC_RTYPE_POS))
>> +#define XGENE_DMA_DESC_BUFADDR_SET(m, v)       \
>> +       (((u64 *)(m))[0] |= (v))
>> +#define XGENE_DMA_DESC_BUFLEN_SET(m, v)                \
>> +       (((u64 *)(m))[0] |= ((u64)(v) << XGENE_DMA_DESC_BUFLEN_POS))
>> +#define XGENE_DMA_DESC_C_SET(m)                        \
>> +       (((u64 *)(m))[1] |= XGENE_DMA_DESC_C_BIT)
>> +#define XGENE_DMA_DESC_FLYBY_SET(m, v)         \
>> +       (((u64 *)(m))[2] |= ((v) << XGENE_DMA_DESC_FLYBY_POS))
>> +#define XGENE_DMA_DESC_MULTI_SET(m, v, i)      \
>> +       (((u64 *)(m))[2] |= ((u64)(v) << (((i) + 1) * 8)))
>> +#define XGENE_DMA_DESC_DR_SET(m)               \
>> +       (((u64 *)(m))[2] |= XGENE_DMA_DESC_DR_BIT)
>> +#define XGENE_DMA_DESC_DST_ADDR_SET(m, v)      \
>> +       (((u64 *)(m))[3] |= (v))
>> +#define XGENE_DMA_DESC_H0ENQ_NUM_SET(m, v)     \
>> +       (((u64 *)(m))[3] |= ((u64)(v) << XGENE_DMA_DESC_HOENQ_NUM_POS))
>> +#define XGENE_DMA_DESC_ELERR_RD(m)             \
>> +       (((m) >> XGENE_DMA_DESC_ELERR_POS) & 0x3)
>> +#define XGENE_DMA_DESC_LERR_RD(m)              \
>> +       (((m) >> XGENE_DMA_DESC_LERR_POS) & 0x7)
>> +#define XGENE_DMA_DESC_STATUS(elerr, lerr)     \
>> +       (((elerr) << 4) | (lerr))
>> +
>> +/* X-Gene DMA descriptor empty s/w signature */
>> +#define XGENE_DMA_DESC_EMPTY_INDEX             0
>> +#define XGENE_DMA_DESC_EMPTY_SIGNATURE         ~0ULL
>> +#define XGENE_DMA_DESC_SET_EMPTY(m)            \
>> +       (((u64 *)(m))[XGENE_DMA_DESC_EMPTY_INDEX] =     \
>> +        XGENE_DMA_DESC_EMPTY_SIGNATURE)
>> +#define XGENE_DMA_DESC_IS_EMPTY(m)             \
>> +       (((u64 *)(m))[XGENE_DMA_DESC_EMPTY_INDEX] ==    \
>> +        XGENE_DMA_DESC_EMPTY_SIGNATURE)
>> +
>> +/* X-Gene DMA configurable parameters defines */
>> +#define XGENE_DMA_RING_NUM             512
>> +#define XGENE_DMA_BUFNUM               0x0
>> +#define XGENE_DMA_CPU_BUFNUM           0x18
>> +#define XGENE_DMA_RING_OWNER_DMA       0x03
>> +#define XGENE_DMA_RING_OWNER_CPU       0x0F
>> +#define XGENE_DMA_RING_TYPE_REGULAR    0x01
>> +#define XGENE_DMA_RING_WQ_DESC_SIZE    32      /* 32 Bytes */
>> +#define XGENE_DMA_RING_NUM_CONFIG      5
>> +#define XGENE_DMA_MAX_CHANNEL          4
>> +#define XGENE_DMA_XOR_CHANNEL          0
>> +#define XGENE_DMA_PQ_CHANNEL           1
>> +#define XGENE_DMA_MAX_BYTE_CNT         0x4000  /* 16 KB */
>> +#define XGENE_DMA_MAX_64B_DESC_BYTE_CNT        0x14000 /* 80 KB */
>> +#define XGENE_DMA_XOR_ALIGNMENT                6       /* 64 Bytes */
>> +#define XGENE_DMA_MAX_XOR_SRC          5
>> +#define XGENE_DMA_16K_BUFFER_LEN_CODE  0x0
>> +#define XGENE_DMA_INVALID_LEN_CODE     0x7800
>> +
>> +/* X-Gene DMA descriptor error codes */
>> +#define ERR_DESC_AXI                   0x01
>> +#define ERR_BAD_DESC                   0x02
>> +#define ERR_READ_DATA_AXI              0x03
>> +#define ERR_WRITE_DATA_AXI             0x04
>> +#define ERR_FBP_TIMEOUT                        0x05
>> +#define ERR_ECC                                0x06
>> +#define ERR_DIFF_SIZE                  0x08
>> +#define ERR_SCT_GAT_LEN                        0x09
>> +#define ERR_CRC_ERR                    0x11
>> +#define ERR_CHKSUM                     0x12
>> +#define ERR_DIF                                0x13
>> +
>> +/* X-Gene DMA error interrupt codes */
>> +#define ERR_DIF_SIZE_INT               0x0
>> +#define ERR_GS_ERR_INT                 0x1
>> +#define ERR_FPB_TIMEO_INT              0x2
>> +#define ERR_WFIFO_OVF_INT              0x3
>> +#define ERR_RFIFO_OVF_INT              0x4
>> +#define ERR_WR_TIMEO_INT               0x5
>> +#define ERR_RD_TIMEO_INT               0x6
>> +#define ERR_WR_ERR_INT                 0x7
>> +#define ERR_RD_ERR_INT                 0x8
>> +#define ERR_BAD_DESC_INT               0x9
>> +#define ERR_DESC_DST_INT               0xA
>> +#define ERR_DESC_SRC_INT               0xB
>> +
>> +/* X-Gene DMA flyby operation code */
>> +#define FLYBY_2SRC_XOR                 0x8
>> +#define FLYBY_3SRC_XOR                 0x9
>> +#define FLYBY_4SRC_XOR                 0xA
>> +#define FLYBY_5SRC_XOR                 0xB
>> +
>> +/* X-Gene DMA SW descriptor flags */
>> +#define XGENE_DMA_FLAG_64B_DESC                BIT(0)
>> +
>> +/* Define to dump X-Gene DMA descriptor */
>> +#define XGENE_DMA_DESC_DUMP(desc, m)   \
>> +       print_hex_dump(KERN_ERR, (m),   \
>> +                       DUMP_PREFIX_ADDRESS, 16, 8, (desc), 32, 0)
>> +
>> +#define to_dma_desc_sw(tx)             \
>> +       container_of(tx, struct xgene_dma_desc_sw, tx)
>> +#define to_dma_chan(dchan)             \
>> +       container_of(dchan, struct xgene_dma_chan, dma_chan)
>> +
>> +#define chan_dbg(chan, fmt, arg...)    \
>> +       dev_dbg(chan->dev, "%s: " fmt, chan->name, ##arg)
>> +#define chan_err(chan, fmt, arg...)    \
>> +       dev_err(chan->dev, "%s: " fmt, chan->name, ##arg)
>> +
>> +struct xgene_dma_desc_hw {
>> +       u64 m0;
>> +       u64 m1;
>> +       u64 m2;
>> +       u64 m3;
>> +};
>> +
>> +enum xgene_dma_ring_cfgsize {
>> +       XGENE_DMA_RING_CFG_SIZE_512B,
>> +       XGENE_DMA_RING_CFG_SIZE_2KB,
>> +       XGENE_DMA_RING_CFG_SIZE_16KB,
>> +       XGENE_DMA_RING_CFG_SIZE_64KB,
>> +       XGENE_DMA_RING_CFG_SIZE_512KB,
>> +       XGENE_DMA_RING_CFG_SIZE_INVALID
>> +};
>> +
>> +struct xgene_dma_ring {
>> +       struct xgene_dma *pdma;
>> +       u8 buf_num;
>> +       u16 id;
>> +       u16 num;
>> +       u16 head;
>> +       u16 owner;
>> +       u16 slots;
>> +       u16 dst_ring_num;
>> +       u32 size;
>> +       void __iomem *cmd;
>> +       void __iomem *cmd_base;
>> +       dma_addr_t desc_paddr;
>> +       u32 state[XGENE_DMA_RING_NUM_CONFIG];
>> +       enum xgene_dma_ring_cfgsize cfgsize;
>> +       union {
>> +               void *desc_vaddr;
>> +               struct xgene_dma_desc_hw *desc_hw;
>> +       };
>> +};
>> +
>> +struct xgene_dma_desc_sw {
>> +       struct xgene_dma_desc_hw desc1;
>> +       struct xgene_dma_desc_hw desc2;
>> +       u32 flags;
>> +       struct list_head node;
>> +       struct list_head tx_list;
>> +       struct dma_async_tx_descriptor tx;
>> +};
>> +
>> +/**
>> + * struct xgene_dma_chan - internal representation of an X-Gene DMA channel
>> + * @dma_chan: dmaengine channel object member
>> + * @pdma: X-Gene DMA device structure reference
>> + * @dev: struct device reference for dma mapping api
>> + * @id: raw id of this channel
>> + * @rx_irq: channel IRQ
>> + * @name: name of X-Gene DMA channel
>> + * @lock: serializes enqueue/dequeue operations to the descriptor pool
>> + * @pending: number of transaction request pushed to DMA controller for
>> + *     execution, but still waiting for completion,
>> + * @max_outstanding: max number of outstanding request we can push to channel
>> + * @ld_pending: descriptors which are queued to run, but have not yet been
>> + *     submitted to the hardware for execution
>> + * @ld_running: descriptors which are currently being executing by the hardware
>> + * @ld_completed: descriptors which have finished execution by the hardware.
>> + *     These descriptors have already had their cleanup actions run. They
>> + *     are waiting for the ACK bit to be set by the async tx API.
>> + * @desc_pool: descriptor pool for DMA operations
>> + * @tasklet: bottom half where all completed descriptors cleans
>> + * @tx_ring: transmit ring descriptor that we use to prepare actual
>> + *     descriptors for further executions
>> + * @rx_ring: receive ring descriptor that we use to get completed DMA
>> + *     descriptors during cleanup time
>> + */
>> +struct xgene_dma_chan {
>> +       struct dma_chan dma_chan;
>> +       struct xgene_dma *pdma;
>> +       struct device *dev;
>> +       int id;
>> +       int rx_irq;
>> +       char name[8];
>> +       spinlock_t lock;
>> +       int pending;
>> +       int max_outstanding;
>> +       struct list_head ld_pending;
>> +       struct list_head ld_running;
>> +       struct list_head ld_completed;
>> +       struct dma_pool *desc_pool;
>> +       struct tasklet_struct tasklet;
>> +       struct xgene_dma_ring tx_ring;
>> +       struct xgene_dma_ring rx_ring;
>> +};
>> +
>> +/**
>> + * struct xgene_dma - internal representation of an X-Gene DMA device
>> + * @err_irq: DMA error irq number
>> + * @ring_num: start id number for DMA ring
>> + * @csr_dma: base for DMA register access
>> + * @csr_ring: base for DMA ring register access
>> + * @csr_ring_cmd: base for DMA ring command register access
>> + * @csr_efuse: base for efuse register access
>> + * @dma_dev: embedded struct dma_device
>> + * @chan: reference to X-Gene DMA channels
>> + */
>> +struct xgene_dma {
>> +       struct device *dev;
>> +       struct clk *clk;
>> +       int err_irq;
>> +       int ring_num;
>> +       void __iomem *csr_dma;
>> +       void __iomem *csr_ring;
>> +       void __iomem *csr_ring_cmd;
>> +       void __iomem *csr_efuse;
>> +       struct dma_device dma_dev[XGENE_DMA_MAX_CHANNEL];
>> +       struct xgene_dma_chan chan[XGENE_DMA_MAX_CHANNEL];
>> +};
>> +
>> +static const char * const xgene_dma_desc_err[] = {
>> +       [ERR_DESC_AXI] = "AXI error when reading src/dst link list",
>> +       [ERR_BAD_DESC] = "ERR or El_ERR fields not set to zero in desc",
>> +       [ERR_READ_DATA_AXI] = "AXI error when reading data",
>> +       [ERR_WRITE_DATA_AXI] = "AXI error when writing data",
>> +       [ERR_FBP_TIMEOUT] = "Timeout on bufpool fetch",
>> +       [ERR_ECC] = "ECC double bit error",
>> +       [ERR_DIFF_SIZE] = "Bufpool too small to hold all the DIF result",
>> +       [ERR_SCT_GAT_LEN] = "Gather and scatter data length not same",
>> +       [ERR_CRC_ERR] = "CRC error",
>> +       [ERR_CHKSUM] = "Checksum error",
>> +       [ERR_DIF] = "DIF error",
>> +};
>> +
>> +static const char * const xgene_dma_err[] = {
>> +       [ERR_DIF_SIZE_INT] = "DIF size error",
>> +       [ERR_GS_ERR_INT] = "Gather scatter not same size error",
>> +       [ERR_FPB_TIMEO_INT] = "Free pool time out error",
>> +       [ERR_WFIFO_OVF_INT] = "Write FIFO over flow error",
>> +       [ERR_RFIFO_OVF_INT] = "Read FIFO over flow error",
>> +       [ERR_WR_TIMEO_INT] = "Write time out error",
>> +       [ERR_RD_TIMEO_INT] = "Read time out error",
>> +       [ERR_WR_ERR_INT] = "HBF bus write error",
>> +       [ERR_RD_ERR_INT] = "HBF bus read error",
>> +       [ERR_BAD_DESC_INT] = "Ring descriptor HE0 not set error",
>> +       [ERR_DESC_DST_INT] = "HFB reading dst link address error",
>> +       [ERR_DESC_SRC_INT] = "HFB reading src link address error",
>> +};
>> +
>> +static bool is_pq_enabled(struct xgene_dma *pdma)
>> +{
>> +       u32 val;
>> +
>> +       val = ioread32(pdma->csr_efuse + XGENE_SOC_JTAG1_SHADOW);
>> +       return !(val & XGENE_DMA_PQ_DISABLE_MASK);
>> +}
>> +
>> +static void xgene_dma_cpu_to_le64(u64 *desc, int count)
>> +{
>> +       int i;
>> +
>> +       for (i = 0; i < count; i++)
>> +               desc[i] = cpu_to_le64(desc[i]);
>> +}
>> +
>> +static u16 xgene_dma_encode_len(u32 len)
>> +{
>> +       return (len < XGENE_DMA_MAX_BYTE_CNT) ?
>> +               len : XGENE_DMA_16K_BUFFER_LEN_CODE;
>> +}
>> +
>> +static u8 xgene_dma_encode_xor_flyby(u32 src_cnt)
>> +{
>> +       static u8 flyby_type[] = {
>> +               FLYBY_2SRC_XOR, /* Dummy */
>> +               FLYBY_2SRC_XOR, /* Dummy */
>> +               FLYBY_2SRC_XOR,
>> +               FLYBY_3SRC_XOR,
>> +               FLYBY_4SRC_XOR,
>> +               FLYBY_5SRC_XOR
>> +       };
>> +
>> +       return flyby_type[src_cnt];
>> +}
>> +
>> +static u32 xgene_dma_ring_desc_cnt(struct xgene_dma_ring *ring)
>> +{
>> +       u32 __iomem *cmd_base = ring->cmd_base;
>> +       u32 ring_state = ioread32(&cmd_base[1]);
>> +
>> +       return XGENE_DMA_RING_DESC_CNT(ring_state);
>> +}
>> +
>> +static void xgene_dma_set_src_buffer(void *ext8, size_t *len,
>> +                                    dma_addr_t *paddr)
>> +{
>> +       size_t nbytes = (*len < XGENE_DMA_MAX_BYTE_CNT) ?
>> +                       *len : XGENE_DMA_MAX_BYTE_CNT;
>> +
>> +       XGENE_DMA_DESC_BUFADDR_SET(ext8, *paddr);
>> +       XGENE_DMA_DESC_BUFLEN_SET(ext8, xgene_dma_encode_len(nbytes));
>> +       *len -= nbytes;
>> +       *paddr += nbytes;
>> +}
>> +
>> +static void xgene_dma_invalidate_buffer(void *ext8)
>> +{
>> +       XGENE_DMA_DESC_BUFLEN_SET(ext8, XGENE_DMA_INVALID_LEN_CODE);
>> +}
>> +
>> +static void *xgene_dma_lookup_ext8(u64 *desc, int idx)
>> +{
>> +       return (idx % 2) ? (desc + idx - 1) : (desc + idx + 1);
>> +}
>> +
>> +static void xgene_dma_init_desc(void *desc, u16 dst_ring_num)
>> +{
>> +       XGENE_DMA_DESC_C_SET(desc); /* Coherent IO */
>> +       XGENE_DMA_DESC_IN_SET(desc);
>> +       XGENE_DMA_DESC_H0ENQ_NUM_SET(desc, dst_ring_num);
>> +       XGENE_DMA_DESC_RTYPE_SET(desc, XGENE_DMA_RING_OWNER_DMA);
>> +}
>> +
>> +static void xgene_dma_prep_cpy_desc(struct xgene_dma_chan *chan,
>> +                                   struct xgene_dma_desc_sw *desc_sw,
>> +                                   dma_addr_t dst, dma_addr_t src,
>> +                                   size_t len)
>> +{
>> +       void *desc1, *desc2;
>> +       int i;
>> +
>> +       /* Get 1st descriptor */
>> +       desc1 = &desc_sw->desc1;
>> +       xgene_dma_init_desc(desc1, chan->tx_ring.dst_ring_num);
>> +
>> +       /* Set destination address */
>> +       XGENE_DMA_DESC_DR_SET(desc1);
>> +       XGENE_DMA_DESC_DST_ADDR_SET(desc1, dst);
>> +
>> +       /* Set 1st source address */
>> +       xgene_dma_set_src_buffer(desc1 + 8, &len, &src);
>> +
>> +       if (len <= 0) {
>> +               desc2 = NULL;
>> +               goto skip_additional_src;
>> +       }
>> +
>> +       /*
>> +        * We need to split this source buffer,
>> +        * and need to use 2nd descriptor
>> +        */
>> +       desc2 = &desc_sw->desc2;
>> +       XGENE_DMA_DESC_NV_SET(desc1);
>> +
>> +       /* Set 2nd to 5th source address */
>> +       for (i = 0; i < 4 && len; i++)
>> +               xgene_dma_set_src_buffer(xgene_dma_lookup_ext8(desc2, i),
>> +                                        &len, &src);
>> +
>> +       /* Invalidate unused source address field */
>> +       for (; i < 4; i++)
>> +               xgene_dma_invalidate_buffer(xgene_dma_lookup_ext8(desc2, i));
>> +
>> +       /* Updated flag that we have prepared 64B descriptor */
>> +       desc_sw->flags |= XGENE_DMA_FLAG_64B_DESC;
>> +
>> +skip_additional_src:
>> +       /* Hardware stores descriptor in little endian format */
>> +       xgene_dma_cpu_to_le64(desc1, 4);
>> +       if (desc2)
>> +               xgene_dma_cpu_to_le64(desc2, 4);
>> +}
>> +
>> +static void xgene_dma_prep_xor_desc(struct xgene_dma_chan *chan,
>> +                                   struct xgene_dma_desc_sw *desc_sw,
>> +                                   dma_addr_t *dst, dma_addr_t *src,
>> +                                   u32 src_cnt, size_t *nbytes,
>> +                                   const u8 *scf)
>> +{
>> +       void *desc1, *desc2;
>> +       size_t len = *nbytes;
>> +       int i;
>> +
>> +       desc1 = &desc_sw->desc1;
>> +       desc2 = &desc_sw->desc2;
>> +
>> +       /* Initialize DMA descriptor */
>> +       xgene_dma_init_desc(desc1, chan->tx_ring.dst_ring_num);
>> +
>> +       /* Set destination address */
>> +       XGENE_DMA_DESC_DR_SET(desc1);
>> +       XGENE_DMA_DESC_DST_ADDR_SET(desc1, *dst);
>> +
>> +       /* We have multiple source addresses, so need to set NV bit*/
>> +       XGENE_DMA_DESC_NV_SET(desc1);
>> +
>> +       /* Set flyby opcode */
>> +       XGENE_DMA_DESC_FLYBY_SET(desc1, xgene_dma_encode_xor_flyby(src_cnt));
>> +
>> +       /* Set 1st to 5th source addresses */
>> +       for (i = 0; i < src_cnt; i++) {
>> +               len = *nbytes;
>> +               xgene_dma_set_src_buffer((i == 0) ? (desc1 + 8) :
>> +                                        xgene_dma_lookup_ext8(desc2, i - 1),
>> +                                        &len, &src[i]);
>> +               XGENE_DMA_DESC_MULTI_SET(desc1, scf[i], i);
>> +       }
>> +
>> +       /* Hardware stores descriptor in little endian format */
>> +       xgene_dma_cpu_to_le64(desc1, 4);
>> +       xgene_dma_cpu_to_le64(desc2, 4);
>> +
>> +       /* Update meta data */
>> +       *nbytes = len;
>> +       *dst += XGENE_DMA_MAX_BYTE_CNT;
>> +
>> +       /* We need always 64B descriptor to perform xor or pq operations */
>> +       desc_sw->flags |= XGENE_DMA_FLAG_64B_DESC;
>> +}
>> +
>> +static dma_cookie_t xgene_dma_tx_submit(struct dma_async_tx_descriptor *tx)
>> +{
>> +       struct xgene_dma_desc_sw *desc;
>> +       struct xgene_dma_chan *chan;
>> +       dma_cookie_t cookie;
>> +
>> +       if (unlikely(!tx))
>> +               return -EINVAL;
>> +
>> +       chan = to_dma_chan(tx->chan);
>> +       desc = to_dma_desc_sw(tx);
>> +
>> +       spin_lock_bh(&chan->lock);
>> +
>> +       cookie = dma_cookie_assign(tx);
>> +
>> +       /* Add this transaction list onto the tail of the pending queue */
>> +       list_splice_tail_init(&desc->tx_list, &chan->ld_pending);
>> +
>> +       spin_unlock_bh(&chan->lock);
>> +
>> +       return cookie;
>> +}
>> +
>> +static void xgene_dma_clean_descriptor(struct xgene_dma_chan *chan,
>> +                                      struct xgene_dma_desc_sw *desc)
>> +{
>> +       list_del(&desc->node);
>> +       chan_dbg(chan, "LD %p free\n", desc);
>> +       dma_pool_free(chan->desc_pool, desc, desc->tx.phys);
>> +}
>> +
>> +static struct xgene_dma_desc_sw *xgene_dma_alloc_descriptor(
>> +                                struct xgene_dma_chan *chan)
>> +{
>> +       struct xgene_dma_desc_sw *desc;
>> +       dma_addr_t phys;
>> +
>> +       desc = dma_pool_alloc(chan->desc_pool, GFP_NOWAIT, &phys);
>> +       if (!desc) {
>> +               chan_err(chan, "Failed to allocate LDs\n");
>> +               return NULL;
>> +       }
>> +
>> +       memset(desc, 0, sizeof(*desc));
>> +
>> +       INIT_LIST_HEAD(&desc->tx_list);
>> +       desc->tx.phys = phys;
>> +       desc->tx.tx_submit = xgene_dma_tx_submit;
>> +       dma_async_tx_descriptor_init(&desc->tx, &chan->dma_chan);
>> +
>> +       chan_dbg(chan, "LD %p allocated\n", desc);
>> +
>> +       return desc;
>> +}
>> +
>> +/**
>> + * xgene_dma_clean_completed_descriptor - free all descriptors which
>> + * has been completed and acked
>> + * @chan: X-Gene DMA channel
>> + *
>> + * This function is used on all completed and acked descriptors.
>> + */
>> +static void xgene_dma_clean_completed_descriptor(struct xgene_dma_chan *chan)
>> +{
>> +       struct xgene_dma_desc_sw *desc, *_desc;
>> +
>> +       /* Run the callback for each descriptor, in order */
>> +       list_for_each_entry_safe(desc, _desc, &chan->ld_completed, node) {
>> +               if (async_tx_test_ack(&desc->tx))
>> +                       xgene_dma_clean_descriptor(chan, desc);
>> +       }
>> +}
>> +
>> +/**
>> + * xgene_dma_run_tx_complete_actions - cleanup a single link descriptor
>> + * @chan: X-Gene DMA channel
>> + * @desc: descriptor to cleanup and free
>> + *
>> + * This function is used on a descriptor which has been executed by the DMA
>> + * controller. It will run any callbacks, submit any dependencies.
>> + */
>> +static void xgene_dma_run_tx_complete_actions(struct xgene_dma_chan *chan,
>> +                                             struct xgene_dma_desc_sw *desc)
>> +{
>> +       struct dma_async_tx_descriptor *tx = &desc->tx;
>> +
>> +       /*
>> +        * If this is not the last transaction in the group,
>> +        * then no need to complete cookie and run any callback as
>> +        * this is not the tx_descriptor which had been sent to caller
>> +        * of this DMA request
>> +        */
>> +
>> +       if (tx->cookie == 0)
>> +               return;
>> +
>> +       dma_cookie_complete(tx);
>> +
>> +       /* Run the link descriptor callback function */
>> +       if (tx->callback)
>> +               tx->callback(tx->callback_param);
>> +
>> +       dma_descriptor_unmap(tx);
>> +
>> +       /* Run any dependencies */
>> +       dma_run_dependencies(tx);
>> +}
>> +
>> +/**
>> + * xgene_dma_clean_running_descriptor - move the completed descriptor from
>> + * ld_running to ld_completed
>> + * @chan: X-Gene DMA channel
>> + * @desc: the descriptor which is completed
>> + *
>> + * Free the descriptor directly if acked by async_tx api,
>> + * else move it to queue ld_completed.
>> + */
>> +static void xgene_dma_clean_running_descriptor(struct xgene_dma_chan *chan,
>> +                                              struct xgene_dma_desc_sw *desc)
>> +{
>> +       /* Remove from the list of running transactions */
>> +       list_del(&desc->node);
>> +
>> +       /*
>> +        * the client is allowed to attach dependent operations
>> +        * until 'ack' is set
>> +        */
>> +       if (!async_tx_test_ack(&desc->tx)) {
>> +               /*
>> +                * Move this descriptor to the list of descriptors which is
>> +                * completed, but still awaiting the 'ack' bit to be set.
>> +                */
>> +               list_add_tail(&desc->node, &chan->ld_completed);
>> +               return;
>> +       }
>> +
>> +       chan_dbg(chan, "LD %p free\n", desc);
>> +       dma_pool_free(chan->desc_pool, desc, desc->tx.phys);
>> +}
>> +
>> +static int xgene_chan_xfer_request(struct xgene_dma_ring *ring,
>> +                                  struct xgene_dma_desc_sw *desc_sw)
>> +{
>> +       struct xgene_dma_desc_hw *desc_hw;
>> +
>> +       /* Check if can push more descriptor to hw for execution */
>> +       if (xgene_dma_ring_desc_cnt(ring) > (ring->slots - 2))
>> +               return -EBUSY;
>> +
>> +       /* Get hw descriptor from DMA tx ring */
>> +       desc_hw = &ring->desc_hw[ring->head];
>> +
>> +       /*
>> +        * Increment the head count to point next
>> +        * descriptor for next time
>> +        */
>> +       if (++ring->head == ring->slots)
>> +               ring->head = 0;
>> +
>> +       /* Copy prepared sw descriptor data to hw descriptor */
>> +       memcpy(desc_hw, &desc_sw->desc1, sizeof(*desc_hw));
>> +
>> +       /*
>> +        * Check if we have prepared 64B descriptor,
>> +        * in this case we need one more hw descriptor
>> +        */
>> +       if (desc_sw->flags & XGENE_DMA_FLAG_64B_DESC) {
>> +               desc_hw = &ring->desc_hw[ring->head];
>> +
>> +               if (++ring->head == ring->slots)
>> +                       ring->head = 0;
>> +
>> +               memcpy(desc_hw, &desc_sw->desc2, sizeof(*desc_hw));
>> +       }
>> +
>> +       /* Notify the hw that we have descriptor ready for execution */
>> +       iowrite32((desc_sw->flags & XGENE_DMA_FLAG_64B_DESC) ?
>> +                 2 : 1, ring->cmd);
>> +
>> +       return 0;
>> +}
>> +
>> +/**
>> + * xgene_chan_xfer_ld_pending - push any pending transactions to hw
>> + * @chan : X-Gene DMA channel
>> + *
>> + * LOCKING: must hold chan->desc_lock
>> + */
>> +static void xgene_chan_xfer_ld_pending(struct xgene_dma_chan *chan)
>> +{
>> +       struct xgene_dma_desc_sw *desc_sw, *_desc_sw;
>> +       int ret;
>> +
>> +       /*
>> +        * If the list of pending descriptors is empty, then we
>> +        * don't need to do any work at all
>> +        */
>> +       if (list_empty(&chan->ld_pending)) {
>> +               chan_dbg(chan, "No pending LDs\n");
>> +               return;
>> +       }
>> +
>> +       /*
>> +        * Move elements from the queue of pending transactions onto the list
>> +        * of running transactions and push it to hw for further executions
>> +        */
>> +       list_for_each_entry_safe(desc_sw, _desc_sw, &chan->ld_pending, node) {
>> +               /*
>> +                * Check if have pushed max number of transactions to hw
>> +                * as capable, so let's stop here and will push remaining
>> +                * elements from pening ld queue after completing some
>> +                * descriptors that we have already pushed
>> +                */
>> +               if (chan->pending >= chan->max_outstanding)
>> +                       return;
>> +
>> +               ret = xgene_chan_xfer_request(&chan->tx_ring, desc_sw);
>> +               if (ret)
>> +                       return;
>> +
>> +               /*
>> +                * Delete this element from ld pending queue and append it to
>> +                * ld running queue
>> +                */
>> +               list_move_tail(&desc_sw->node, &chan->ld_running);
>> +
>> +               /* Increment the pending transaction count */
>> +               chan->pending++;
>> +       }
>> +}
>> +
>> +/**
>> + * xgene_dma_cleanup_descriptors - cleanup link descriptors which are completed
>> + * and move them to ld_completed to free until flag 'ack' is set
>> + * @chan: X-Gene DMA channel
>> + *
>> + * This function is used on descriptors which have been executed by the DMA
>> + * controller. It will run any callbacks, submit any dependencies, then
>> + * free these descriptors if flag 'ack' is set.
>> + */
>> +static void xgene_dma_cleanup_descriptors(struct xgene_dma_chan *chan)
>> +{
>> +       struct xgene_dma_ring *ring = &chan->rx_ring;
>> +       struct xgene_dma_desc_sw *desc_sw, *_desc_sw;
>> +       struct xgene_dma_desc_hw *desc_hw;
>> +       u8 status;
>> +
>> +       /* Clean already completed and acked descriptors */
>> +       xgene_dma_clean_completed_descriptor(chan);
>> +
>> +       /* Run the callback for each descriptor, in order */
>> +       list_for_each_entry_safe(desc_sw, _desc_sw, &chan->ld_running, node) {
>> +               /* Get subsequent hw descriptor from DMA rx ring */
>> +               desc_hw = &ring->desc_hw[ring->head];
>> +
>> +               /* Check if this descriptor has been completed */
>> +               if (unlikely(XGENE_DMA_DESC_IS_EMPTY(desc_hw)))
>> +                       break;
>> +
>> +               if (++ring->head == ring->slots)
>> +                       ring->head = 0;
>> +
>> +               /* Check if we have any error with DMA transactions */
>> +               status = XGENE_DMA_DESC_STATUS(
>> +                               XGENE_DMA_DESC_ELERR_RD(le64_to_cpu(
>> +                                                       desc_hw->m0)),
>> +                               XGENE_DMA_DESC_LERR_RD(le64_to_cpu(
>> +                                                      desc_hw->m0)));
>> +               if (status) {
>> +                       /* Print the DMA error type */
>> +                       chan_err(chan, "%s\n", xgene_dma_desc_err[status]);
>> +
>> +                       /*
>> +                        * We have DMA transactions error here. Dump DMA Tx
>> +                        * and Rx descriptors for this request */
>> +                       XGENE_DMA_DESC_DUMP(&desc_sw->desc1,
>> +                                           "X-Gene DMA TX DESC1: ");
>> +
>> +                       if (desc_sw->flags & XGENE_DMA_FLAG_64B_DESC)
>> +                               XGENE_DMA_DESC_DUMP(&desc_sw->desc2,
>> +                                                   "X-Gene DMA TX DESC2: ");
>> +
>> +                       XGENE_DMA_DESC_DUMP(desc_hw,
>> +                                           "X-Gene DMA RX ERR DESC: ");
>> +               }
>> +
>> +               /* Notify the hw about this completed descriptor */
>> +               iowrite32(-1, ring->cmd);
>> +
>> +               /* Mark this hw descriptor as processed */
>> +               XGENE_DMA_DESC_SET_EMPTY(desc_hw);
>> +
>> +               xgene_dma_run_tx_complete_actions(chan, desc_sw);
>> +
>> +               xgene_dma_clean_running_descriptor(chan, desc_sw);
>> +
>> +               /*
>> +                * Decrement the pending transaction count
>> +                * as we have processed one
>> +                */
>> +               chan->pending--;
>> +       }
>> +
>> +       /*
>> +        * Start any pending transactions automatically
>> +        * In the ideal case, we keep the DMA controller busy while we go
>> +        * ahead and free the descriptors below.
>> +        */
>> +       xgene_chan_xfer_ld_pending(chan);
>> +}
>> +
>> +static int xgene_dma_alloc_chan_resources(struct dma_chan *dchan)
>> +{
>> +       struct xgene_dma_chan *chan = to_dma_chan(dchan);
>> +
>> +       /* Has this channel already been allocated? */
>> +       if (chan->desc_pool)
>> +               return 1;
>> +
>> +       chan->desc_pool = dma_pool_create(chan->name, chan->dev,
>> +                                         sizeof(struct xgene_dma_desc_sw),
>> +                                         0, 0);
>> +       if (!chan->desc_pool) {
>> +               chan_err(chan, "Failed to allocate descriptor pool\n");
>> +               return -ENOMEM;
>> +       }
>> +
>> +       chan_dbg(chan, "Allocate descripto pool\n");
>> +
>> +       return 1;
>> +}
>> +
>> +/**
>> + * xgene_dma_free_desc_list - Free all descriptors in a queue
>> + * @chan: X-Gene DMA channel
>> + * @list: the list to free
>> + *
>> + * LOCKING: must hold chan->desc_lock
>> + */
>> +static void xgene_dma_free_desc_list(struct xgene_dma_chan *chan,
>> +                                    struct list_head *list)
>> +{
>> +       struct xgene_dma_desc_sw *desc, *_desc;
>> +
>> +       list_for_each_entry_safe(desc, _desc, list, node)
>> +               xgene_dma_clean_descriptor(chan, desc);
>> +}
>> +
>> +static void xgene_dma_free_tx_desc_list(struct xgene_dma_chan *chan,
>> +                                       struct list_head *list)
>> +{
>> +       struct xgene_dma_desc_sw *desc, *_desc;
>> +
>> +       list_for_each_entry_safe(desc, _desc, list, node)
>> +               xgene_dma_clean_descriptor(chan, desc);
>> +}
>> +
>> +static void xgene_dma_free_chan_resources(struct dma_chan *dchan)
>> +{
>> +       struct xgene_dma_chan *chan = to_dma_chan(dchan);
>> +
>> +       chan_dbg(chan, "Free all resources\n");
>> +
>> +       if (!chan->desc_pool)
>> +               return;
>> +
>> +       spin_lock_bh(&chan->lock);
>> +
>> +       /* Process all running descriptor */
>> +       xgene_dma_cleanup_descriptors(chan);
>> +
>> +       /* Clean all link descriptor queues */
>> +       xgene_dma_free_desc_list(chan, &chan->ld_pending);
>> +       xgene_dma_free_desc_list(chan, &chan->ld_running);
>> +       xgene_dma_free_desc_list(chan, &chan->ld_completed);
>> +
>> +       spin_unlock_bh(&chan->lock);
>> +
>> +       /* Delete this channel DMA pool */
>> +       dma_pool_destroy(chan->desc_pool);
>> +       chan->desc_pool = NULL;
>> +}
>> +
>> +static struct dma_async_tx_descriptor *xgene_dma_prep_memcpy(
>> +       struct dma_chan *dchan, dma_addr_t dst, dma_addr_t src,
>> +       size_t len, unsigned long flags)
>> +{
>> +       struct xgene_dma_desc_sw *first = NULL, *new;
>> +       struct xgene_dma_chan *chan;
>> +       size_t copy;
>> +
>> +       if (unlikely(!dchan || !len))
>> +               return NULL;
>> +
>> +       chan = to_dma_chan(dchan);
>> +
>> +       do {
>> +               /* Allocate the link descriptor from DMA pool */
>> +               new = xgene_dma_alloc_descriptor(chan);
>> +               if (!new)
>> +                       goto fail;
>> +
>> +               /* Create the largest transaction possible */
>> +               copy = min_t(size_t, len, XGENE_DMA_MAX_64B_DESC_BYTE_CNT);
>> +
>> +               /* Prepare DMA descriptor */
>> +               xgene_dma_prep_cpy_desc(chan, new, dst, src, copy);
>> +
>> +               if (!first)
>> +                       first = new;
>> +
>> +               new->tx.cookie = 0;
>> +               async_tx_ack(&new->tx);
>> +
>> +               /* Update metadata */
>> +               len -= copy;
>> +               dst += copy;
>> +               src += copy;
>> +
>> +               /* Insert the link descriptor to the LD ring */
>> +               list_add_tail(&new->node, &first->tx_list);
>> +       } while (len);
>> +
>> +       new->tx.flags = flags; /* client is in control of this ack */
>> +       new->tx.cookie = -EBUSY;
>> +       list_splice(&first->tx_list, &new->tx_list);
>> +
>> +       return &new->tx;
>> +
>> +fail:
>> +       if (!first)
>> +               return NULL;
>> +
>> +       xgene_dma_free_tx_desc_list(chan, &first->tx_list);
>> +       return NULL;
>> +}
>> +
>> +static struct dma_async_tx_descriptor *xgene_dma_prep_sg(
>> +       struct dma_chan *dchan, struct scatterlist *dst_sg,
>> +       u32 dst_nents, struct scatterlist *src_sg,
>> +       u32 src_nents, unsigned long flags)
>> +{
>> +       struct xgene_dma_desc_sw *first = NULL, *new = NULL;
>> +       struct xgene_dma_chan *chan;
>> +       size_t dst_avail, src_avail;
>> +       dma_addr_t dst, src;
>> +       size_t len;
>> +
>> +       if (unlikely(!dchan))
>> +               return NULL;
>> +
>> +       if (unlikely(!dst_nents || !src_nents))
>> +               return NULL;
>> +
>> +       if (unlikely(!dst_sg || !src_sg))
>> +               return NULL;
>> +
>> +       chan = to_dma_chan(dchan);
>> +
>> +       /* Get prepared for the loop */
>> +       dst_avail = sg_dma_len(dst_sg);
>> +       src_avail = sg_dma_len(src_sg);
>> +       dst_nents--;
>> +       src_nents--;
>> +
>> +       /* Run until we are out of scatterlist entries */
>> +       while (true) {
>> +               /* Create the largest transaction possible */
>> +               len = min_t(size_t, src_avail, dst_avail);
>> +               len = min_t(size_t, len, XGENE_DMA_MAX_64B_DESC_BYTE_CNT);
>> +               if (len == 0)
>> +                       goto fetch;
>> +
>> +               dst = sg_dma_address(dst_sg) + sg_dma_len(dst_sg) - dst_avail;
>> +               src = sg_dma_address(src_sg) + sg_dma_len(src_sg) - src_avail;
>> +
>> +               /* Allocate the link descriptor from DMA pool */
>> +               new = xgene_dma_alloc_descriptor(chan);
>> +               if (!new)
>> +                       goto fail;
>> +
>> +               /* Prepare DMA descriptor */
>> +               xgene_dma_prep_cpy_desc(chan, new, dst, src, len);
>> +
>> +               if (!first)
>> +                       first = new;
>> +
>> +               new->tx.cookie = 0;
>> +               async_tx_ack(&new->tx);
>> +
>> +               /* update metadata */
>> +               dst_avail -= len;
>> +               src_avail -= len;
>> +
>> +               /* Insert the link descriptor to the LD ring */
>> +               list_add_tail(&new->node, &first->tx_list);
>> +
>> +fetch:
>> +               /* fetch the next dst scatterlist entry */
>> +               if (dst_avail == 0) {
>> +                       /* no more entries: we're done */
>> +                       if (dst_nents == 0)
>> +                               break;
>> +
>> +                       /* fetch the next entry: if there are no more: done */
>> +                       dst_sg = sg_next(dst_sg);
>> +                       if (!dst_sg)
>> +                               break;
>> +
>> +                       dst_nents--;
>> +                       dst_avail = sg_dma_len(dst_sg);
>> +               }
>> +
>> +               /* fetch the next src scatterlist entry */
>> +               if (src_avail == 0) {
>> +                       /* no more entries: we're done */
>> +                       if (src_nents == 0)
>> +                               break;
>> +
>> +                       /* fetch the next entry: if there are no more: done */
>> +                       src_sg = sg_next(src_sg);
>> +                       if (!src_sg)
>> +                               break;
>> +
>> +                       src_nents--;
>> +                       src_avail = sg_dma_len(src_sg);
>> +               }
>> +       }
>> +
>> +       if (!new)
>> +               return NULL;
>> +
>> +       new->tx.flags = flags; /* client is in control of this ack */
>> +       new->tx.cookie = -EBUSY;
>> +       list_splice(&first->tx_list, &new->tx_list);
>> +
>> +       return &new->tx;
>> +fail:
>> +       if (!first)
>> +               return NULL;
>> +
>> +       xgene_dma_free_tx_desc_list(chan, &first->tx_list);
>> +       return NULL;
>> +}
>> +
>> +static struct dma_async_tx_descriptor *xgene_dma_prep_xor(
>> +       struct dma_chan *dchan, dma_addr_t dst, dma_addr_t *src,
>> +       u32 src_cnt, size_t len, unsigned long flags)
>> +{
>> +       struct xgene_dma_desc_sw *first = NULL, *new;
>> +       struct xgene_dma_chan *chan;
>> +       static u8 multi[XGENE_DMA_MAX_XOR_SRC] = {
>> +                               0x01, 0x01, 0x01, 0x01, 0x01};
>> +
>> +       if (unlikely(!dchan || !len))
>> +               return NULL;
>> +
>> +       chan = to_dma_chan(dchan);
>> +
>> +       do {
>> +               /* Allocate the link descriptor from DMA pool */
>> +               new = xgene_dma_alloc_descriptor(chan);
>> +               if (!new)
>> +                       goto fail;
>> +
>> +               /* Prepare xor DMA descriptor */
>> +               xgene_dma_prep_xor_desc(chan, new, &dst, src,
>> +                                       src_cnt, &len, multi);
>> +
>> +               if (!first)
>> +                       first = new;
>> +
>> +               new->tx.cookie = 0;
>> +               async_tx_ack(&new->tx);
>> +
>> +               /* Insert the link descriptor to the LD ring */
>> +               list_add_tail(&new->node, &first->tx_list);
>> +       } while (len);
>> +
>> +       new->tx.flags = flags; /* client is in control of this ack */
>> +       new->tx.cookie = -EBUSY;
>> +       list_splice(&first->tx_list, &new->tx_list);
>> +
>> +       return &new->tx;
>> +
>> +fail:
>> +       if (!first)
>> +               return NULL;
>> +
>> +       xgene_dma_free_tx_desc_list(chan, &first->tx_list);
>> +       return NULL;
>> +}
>> +
>> +static struct dma_async_tx_descriptor *xgene_dma_prep_pq(
>> +       struct dma_chan *dchan, dma_addr_t *dst, dma_addr_t *src,
>> +       u32 src_cnt, const u8 *scf, size_t len, unsigned long flags)
>> +{
>> +       struct xgene_dma_desc_sw *first = NULL, *new;
>> +       struct xgene_dma_chan *chan;
>> +       size_t _len = len;
>> +       dma_addr_t _src[XGENE_DMA_MAX_XOR_SRC];
>> +       static u8 multi[XGENE_DMA_MAX_XOR_SRC] = {0x01, 0x01, 0x01, 0x01, 0x01};
>> +
>> +       if (unlikely(!dchan || !len))
>> +               return NULL;
>> +
>> +       chan = to_dma_chan(dchan);
>> +
>> +       /*
>> +        * Save source addresses on local variable, may be we have to
>> +        * prepare two descriptor to generate P and Q if both enabled
>> +        * in the flags by client
>> +        */
>> +       memcpy(_src, src, sizeof(*src) * src_cnt);
>> +
>> +       if (flags & DMA_PREP_PQ_DISABLE_P)
>> +               len = 0;
>> +
>> +       if (flags & DMA_PREP_PQ_DISABLE_Q)
>> +               _len = 0;
>> +
>> +       do {
>> +               /* Allocate the link descriptor from DMA pool */
>> +               new = xgene_dma_alloc_descriptor(chan);
>> +               if (!new)
>> +                       goto fail;
>> +
>> +               if (!first)
>> +                       first = new;
>> +
>> +               new->tx.cookie = 0;
>> +               async_tx_ack(&new->tx);
>> +
>> +               /* Insert the link descriptor to the LD ring */
>> +               list_add_tail(&new->node, &first->tx_list);
>> +
>> +               /*
>> +                * Prepare DMA descriptor to generate P,
>> +                * if DMA_PREP_PQ_DISABLE_P flag is not set
>> +                */
>> +               if (len) {
>> +                       xgene_dma_prep_xor_desc(chan, new, &dst[0], src,
>> +                                               src_cnt, &len, multi);
>> +                       continue;
>> +               }
>> +
>> +               /*
>> +                * Prepare DMA descriptor to generate Q,
>> +                * if DMA_PREP_PQ_DISABLE_Q flag is not set
>> +                */
>> +               if (_len) {
>> +                       xgene_dma_prep_xor_desc(chan, new, &dst[1], _src,
>> +                                               src_cnt, &_len, scf);
>> +               }
>> +       } while (len || _len);
>> +
>> +       new->tx.flags = flags; /* client is in control of this ack */
>> +       new->tx.cookie = -EBUSY;
>> +       list_splice(&first->tx_list, &new->tx_list);
>> +
>> +       return &new->tx;
>> +
>> +fail:
>> +       if (!first)
>> +               return NULL;
>> +
>> +       xgene_dma_free_tx_desc_list(chan, &first->tx_list);
>> +       return NULL;
>> +}
>> +
>> +static void xgene_dma_issue_pending(struct dma_chan *dchan)
>> +{
>> +       struct xgene_dma_chan *chan = to_dma_chan(dchan);
>> +
>> +       spin_lock_bh(&chan->lock);
>> +       xgene_chan_xfer_ld_pending(chan);
>> +       spin_unlock_bh(&chan->lock);
>> +}
>> +
>> +static enum dma_status xgene_dma_tx_status(struct dma_chan *dchan,
>> +                                          dma_cookie_t cookie,
>> +                                          struct dma_tx_state *txstate)
>> +{
>> +       return dma_cookie_status(dchan, cookie, txstate);
>> +}
>> +
>> +static void xgene_dma_tasklet_cb(unsigned long data)
>> +{
>> +       struct xgene_dma_chan *chan = (struct xgene_dma_chan *)data;
>> +
>> +       spin_lock_bh(&chan->lock);
>> +
>> +       /* Run all cleanup for descriptors which have been completed */
>> +       xgene_dma_cleanup_descriptors(chan);
>> +
>> +       /* Re-enable DMA channel IRQ */
>> +       enable_irq(chan->rx_irq);
>> +
>> +       spin_unlock_bh(&chan->lock);
>> +}
>> +
>> +static irqreturn_t xgene_dma_chan_ring_isr(int irq, void *id)
>> +{
>> +       struct xgene_dma_chan *chan = (struct xgene_dma_chan *)id;
>> +
>> +       BUG_ON(!chan);
>> +
>> +       /*
>> +        * Disable DMA channel IRQ until we process completed
>> +        * descriptors
>> +        */
>> +       disable_irq_nosync(chan->rx_irq);
>> +
>> +       /*
>> +        * Schedule the tasklet to handle all cleanup of the current
>> +        * transaction. It will start a new transaction if there is
>> +        * one pending.
>> +        */
>> +       tasklet_schedule(&chan->tasklet);
>> +
>> +       return IRQ_HANDLED;
>> +}
>> +
>> +static irqreturn_t xgene_dma_err_isr(int irq, void *id)
>> +{
>> +       struct xgene_dma *pdma = (struct xgene_dma *)id;
>> +       unsigned long int_mask;
>> +       u32 val, i;
>> +
>> +       val = ioread32(pdma->csr_dma + XGENE_DMA_INT);
>> +
>> +       /* Clear DMA interrupts */
>> +       iowrite32(val, pdma->csr_dma + XGENE_DMA_INT);
>> +
>> +       /* Print DMA error info */
>> +       int_mask = val >> XGENE_DMA_INT_MASK_SHIFT;
>> +       for_each_set_bit(i, &int_mask, ARRAY_SIZE(xgene_dma_err))
>> +               dev_err(pdma->dev,
>> +                       "Interrupt status 0x%08X %s\n", val, xgene_dma_err[i]);
>> +
>> +       return IRQ_HANDLED;
>> +}
>> +
>> +static void xgene_dma_wr_ring_state(struct xgene_dma_ring *ring)
>> +{
>> +       int i;
>> +
>> +       iowrite32(ring->num, ring->pdma->csr_ring + XGENE_DMA_RING_STATE);
>> +
>> +       for (i = 0; i < XGENE_DMA_RING_NUM_CONFIG; i++)
>> +               iowrite32(ring->state[i], ring->pdma->csr_ring +
>> +                         XGENE_DMA_RING_STATE_WR_BASE + (i * 4));
>> +}
>> +
>> +static void xgene_dma_clr_ring_state(struct xgene_dma_ring *ring)
>> +{
>> +       memset(ring->state, 0, sizeof(u32) * XGENE_DMA_RING_NUM_CONFIG);
>> +       xgene_dma_wr_ring_state(ring);
>> +}
>> +
>> +static void xgene_dma_setup_ring(struct xgene_dma_ring *ring)
>> +{
>> +       void *ring_cfg = ring->state;
>> +       u64 addr = ring->desc_paddr;
>> +       void *desc;
>> +       u32 i, val;
>> +
>> +       ring->slots = ring->size / XGENE_DMA_RING_WQ_DESC_SIZE;
>> +
>> +       /* Clear DMA ring state */
>> +       xgene_dma_clr_ring_state(ring);
>> +
>> +       /* Set DMA ring type */
>> +       XGENE_DMA_RING_TYPE_SET(ring_cfg, XGENE_DMA_RING_TYPE_REGULAR);
>> +
>> +       if (ring->owner == XGENE_DMA_RING_OWNER_DMA) {
>> +               /* Set recombination buffer and timeout */
>> +               XGENE_DMA_RING_RECOMBBUF_SET(ring_cfg);
>> +               XGENE_DMA_RING_RECOMTIMEOUTL_SET(ring_cfg);
>> +               XGENE_DMA_RING_RECOMTIMEOUTH_SET(ring_cfg);
>> +       }
>> +
>> +       /* Initialize DMA ring state */
>> +       XGENE_DMA_RING_SELTHRSH_SET(ring_cfg);
>> +       XGENE_DMA_RING_ACCEPTLERR_SET(ring_cfg);
>> +       XGENE_DMA_RING_COHERENT_SET(ring_cfg);
>> +       XGENE_DMA_RING_ADDRL_SET(ring_cfg, addr);
>> +       XGENE_DMA_RING_ADDRH_SET(ring_cfg, addr);
>> +       XGENE_DMA_RING_SIZE_SET(ring_cfg, ring->cfgsize);
>> +
>> +       /* Write DMA ring configurations */
>> +       xgene_dma_wr_ring_state(ring);
>> +
>> +       /* Set DMA ring id */
>> +       iowrite32(XGENE_DMA_RING_ID_SETUP(ring->id),
>> +                 ring->pdma->csr_ring + XGENE_DMA_RING_ID);
>> +
>> +       /* Set DMA ring buffer */
>> +       iowrite32(XGENE_DMA_RING_ID_BUF_SETUP(ring->num),
>> +                 ring->pdma->csr_ring + XGENE_DMA_RING_ID_BUF);
>> +
>> +       if (ring->owner != XGENE_DMA_RING_OWNER_CPU)
>> +               return;
>> +
>> +       /* Set empty signature to DMA Rx ring descriptors */
>> +       for (i = 0; i < ring->slots; i++) {
>> +               desc = &ring->desc_hw[i];
>> +               XGENE_DMA_DESC_SET_EMPTY(desc);
>> +       }
>> +
>> +       /* Enable DMA Rx ring interrupt */
>> +       val = ioread32(ring->pdma->csr_ring + XGENE_DMA_RING_NE_INT_MODE);
>> +       XGENE_DMA_RING_NE_INT_MODE_SET(val, ring->buf_num);
>> +       iowrite32(val, ring->pdma->csr_ring + XGENE_DMA_RING_NE_INT_MODE);
>> +}
>> +
>> +static void xgene_dma_clear_ring(struct xgene_dma_ring *ring)
>> +{
>> +       u32 ring_id, val;
>> +
>> +       if (ring->owner == XGENE_DMA_RING_OWNER_CPU) {
>> +               /* Disable DMA Rx ring interrupt */
>> +               val = ioread32(ring->pdma->csr_ring +
>> +                              XGENE_DMA_RING_NE_INT_MODE);
>> +               XGENE_DMA_RING_NE_INT_MODE_RESET(val, ring->buf_num);
>> +               iowrite32(val, ring->pdma->csr_ring +
>> +                         XGENE_DMA_RING_NE_INT_MODE);
>> +       }
>> +
>> +       /* Clear DMA ring state */
>> +       ring_id = XGENE_DMA_RING_ID_SETUP(ring->id);
>> +       iowrite32(ring_id, ring->pdma->csr_ring + XGENE_DMA_RING_ID);
>> +
>> +       iowrite32(0, ring->pdma->csr_ring + XGENE_DMA_RING_ID_BUF);
>> +       xgene_dma_clr_ring_state(ring);
>> +}
>> +
>> +static void xgene_dma_set_ring_cmd(struct xgene_dma_ring *ring)
>> +{
>> +       ring->cmd_base = ring->pdma->csr_ring_cmd +
>> +                               XGENE_DMA_RING_CMD_BASE_OFFSET((ring->num -
>> +                                                         XGENE_DMA_RING_NUM));
>> +
>> +       ring->cmd = ring->cmd_base + XGENE_DMA_RING_CMD_OFFSET;
>> +}
>> +
>> +static int xgene_dma_get_ring_size(struct xgene_dma_chan *chan,
>> +                                  enum xgene_dma_ring_cfgsize cfgsize)
>> +{
>> +       int size;
>> +
>> +       switch (cfgsize) {
>> +       case XGENE_DMA_RING_CFG_SIZE_512B:
>> +               size = 0x200;
>> +               break;
>> +       case XGENE_DMA_RING_CFG_SIZE_2KB:
>> +               size = 0x800;
>> +               break;
>> +       case XGENE_DMA_RING_CFG_SIZE_16KB:
>> +               size = 0x4000;
>> +               break;
>> +       case XGENE_DMA_RING_CFG_SIZE_64KB:
>> +               size = 0x10000;
>> +               break;
>> +       case XGENE_DMA_RING_CFG_SIZE_512KB:
>> +               size = 0x80000;
>> +               break;
>> +       default:
>> +               chan_err(chan, "Unsupported cfg ring size %d\n", cfgsize);
>> +               return -EINVAL;
>> +       }
>> +
>> +       return size;
>> +}
>> +
>> +static void xgene_dma_delete_ring_one(struct xgene_dma_ring *ring)
>> +{
>> +       /* Clear DMA ring configurations */
>> +       xgene_dma_clear_ring(ring);
>> +
>> +       /* De-allocate DMA ring descriptor */
>> +       if (ring->desc_vaddr) {
>> +               dma_free_coherent(ring->pdma->dev, ring->size,
>> +                                 ring->desc_vaddr, ring->desc_paddr);
>> +               ring->desc_vaddr = NULL;
>> +       }
>> +}
>> +
>> +static void xgene_dma_delete_chan_rings(struct xgene_dma_chan *chan)
>> +{
>> +       xgene_dma_delete_ring_one(&chan->rx_ring);
>> +       xgene_dma_delete_ring_one(&chan->tx_ring);
>> +}
>> +
>> +static int xgene_dma_create_ring_one(struct xgene_dma_chan *chan,
>> +                                    struct xgene_dma_ring *ring,
>> +                                    enum xgene_dma_ring_cfgsize cfgsize)
>> +{
>> +       /* Setup DMA ring descriptor variables */
>> +       ring->pdma = chan->pdma;
>> +       ring->cfgsize = cfgsize;
>> +       ring->num = chan->pdma->ring_num++;
>> +       ring->id = XGENE_DMA_RING_ID_GET(ring->owner, ring->buf_num);
>> +
>> +       ring->size = xgene_dma_get_ring_size(chan, cfgsize);
>> +       if (ring->size <= 0)
>> +               return ring->size;
>> +
>> +       /* Allocate memory for DMA ring descriptor */
>> +       ring->desc_vaddr = dma_zalloc_coherent(chan->dev, ring->size,
>> +                                              &ring->desc_paddr, GFP_KERNEL);
>> +       if (!ring->desc_vaddr) {
>> +               chan_err(chan, "Failed to allocate ring desc\n");
>> +               return -ENOMEM;
>> +       }
>> +
>> +       /* Configure and enable DMA ring */
>> +       xgene_dma_set_ring_cmd(ring);
>> +       xgene_dma_setup_ring(ring);
>> +
>> +       return 0;
>> +}
>> +
>> +static int xgene_dma_create_chan_rings(struct xgene_dma_chan *chan)
>> +{
>> +       struct xgene_dma_ring *rx_ring = &chan->rx_ring;
>> +       struct xgene_dma_ring *tx_ring = &chan->tx_ring;
>> +       int ret;
>> +
>> +       /* Create DMA Rx ring descriptor */
>> +       rx_ring->owner = XGENE_DMA_RING_OWNER_CPU;
>> +       rx_ring->buf_num = XGENE_DMA_CPU_BUFNUM + chan->id;
>> +
>> +       ret = xgene_dma_create_ring_one(chan, rx_ring,
>> +                                       XGENE_DMA_RING_CFG_SIZE_64KB);
>> +       if (ret)
>> +               return ret;
>> +
>> +       chan_dbg(chan, "Rx ring id 0x%X num %d desc 0x%p\n",
>> +                rx_ring->id, rx_ring->num, rx_ring->desc_vaddr);
>> +
>> +       /* Create DMA Tx ring descriptor */
>> +       tx_ring->owner = XGENE_DMA_RING_OWNER_DMA;
>> +       tx_ring->buf_num = XGENE_DMA_BUFNUM + chan->id;
>> +
>> +       ret = xgene_dma_create_ring_one(chan, tx_ring,
>> +                                       XGENE_DMA_RING_CFG_SIZE_64KB);
>> +       if (ret) {
>> +               xgene_dma_delete_ring_one(rx_ring);
>> +               return ret;
>> +       }
>> +
>> +       tx_ring->dst_ring_num = XGENE_DMA_RING_DST_ID(rx_ring->num);
>> +
>> +       chan_dbg(chan,
>> +                "Tx ring id 0x%X num %d desc 0x%p\n",
>> +                tx_ring->id, tx_ring->num, tx_ring->desc_vaddr);
>> +
>> +       /* Set the max outstanding request possible to this channel */
>> +       chan->max_outstanding = rx_ring->slots;
>> +
>> +       return ret;
>> +}
>> +
>> +static int xgene_dma_init_rings(struct xgene_dma *pdma)
>> +{
>> +       int ret, i, j;
>> +
>> +       for (i = 0; i < XGENE_DMA_MAX_CHANNEL; i++) {
>> +               ret = xgene_dma_create_chan_rings(&pdma->chan[i]);
>> +               if (ret) {
>> +                       for (j = 0; j < i; j++)
>> +                               xgene_dma_delete_chan_rings(&pdma->chan[j]);
>> +                       return ret;
>> +               }
>> +       }
>> +
>> +       return ret;
>> +}
>> +
>> +static void xgene_dma_enable(struct xgene_dma *pdma)
>> +{
>> +       u32 val;
>> +
>> +       /* Configure and enable DMA engine */
>> +       val = ioread32(pdma->csr_dma + XGENE_DMA_GCR);
>> +       XGENE_DMA_CH_SETUP(val);
>> +       XGENE_DMA_ENABLE(val);
>> +       iowrite32(val, pdma->csr_dma + XGENE_DMA_GCR);
>> +}
>> +
>> +static void xgene_dma_disable(struct xgene_dma *pdma)
>> +{
>> +       u32 val;
>> +
>> +       val = ioread32(pdma->csr_dma + XGENE_DMA_GCR);
>> +       XGENE_DMA_DISABLE(val);
>> +       iowrite32(val, pdma->csr_dma + XGENE_DMA_GCR);
>> +}
>> +
>> +static void xgene_dma_mask_interrupts(struct xgene_dma *pdma)
>> +{
>> +       /*
>> +        * Mask DMA ring overflow, underflow and
>> +        * AXI write/read error interrupts
>> +        */
>> +       iowrite32(XGENE_DMA_INT_ALL_MASK,
>> +                 pdma->csr_dma + XGENE_DMA_RING_INT0_MASK);
>> +       iowrite32(XGENE_DMA_INT_ALL_MASK,
>> +                 pdma->csr_dma + XGENE_DMA_RING_INT1_MASK);
>> +       iowrite32(XGENE_DMA_INT_ALL_MASK,
>> +                 pdma->csr_dma + XGENE_DMA_RING_INT2_MASK);
>> +       iowrite32(XGENE_DMA_INT_ALL_MASK,
>> +                 pdma->csr_dma + XGENE_DMA_RING_INT3_MASK);
>> +       iowrite32(XGENE_DMA_INT_ALL_MASK,
>> +                 pdma->csr_dma + XGENE_DMA_RING_INT4_MASK);
>> +
>> +       /* Mask DMA error interrupts */
>> +       iowrite32(XGENE_DMA_INT_ALL_MASK, pdma->csr_dma + XGENE_DMA_INT_MASK);
>> +}
>> +
>> +static void xgene_dma_unmask_interrupts(struct xgene_dma *pdma)
>> +{
>> +       /*
>> +        * Unmask DMA ring overflow, underflow and
>> +        * AXI write/read error interrupts
>> +        */
>> +       iowrite32(XGENE_DMA_INT_ALL_UNMASK,
>> +                 pdma->csr_dma + XGENE_DMA_RING_INT0_MASK);
>> +       iowrite32(XGENE_DMA_INT_ALL_UNMASK,
>> +                 pdma->csr_dma + XGENE_DMA_RING_INT1_MASK);
>> +       iowrite32(XGENE_DMA_INT_ALL_UNMASK,
>> +                 pdma->csr_dma + XGENE_DMA_RING_INT2_MASK);
>> +       iowrite32(XGENE_DMA_INT_ALL_UNMASK,
>> +                 pdma->csr_dma + XGENE_DMA_RING_INT3_MASK);
>> +       iowrite32(XGENE_DMA_INT_ALL_UNMASK,
>> +                 pdma->csr_dma + XGENE_DMA_RING_INT4_MASK);
>> +
>> +       /* Unmask DMA error interrupts */
>> +       iowrite32(XGENE_DMA_INT_ALL_UNMASK,
>> +                 pdma->csr_dma + XGENE_DMA_INT_MASK);
>> +}
>> +
>> +static void xgene_dma_init_hw(struct xgene_dma *pdma)
>> +{
>> +       u32 val;
>> +
>> +       /* Associate DMA ring to corresponding ring HW */
>> +       iowrite32(XGENE_DMA_ASSOC_RING_MNGR1,
>> +                 pdma->csr_dma + XGENE_DMA_CFG_RING_WQ_ASSOC);
>> +
>> +       /* Configure RAID6 polynomial control setting */
>> +       if (is_pq_enabled(pdma))
>> +               iowrite32(XGENE_DMA_RAID6_MULTI_CTRL(0x1D),
>> +                         pdma->csr_dma + XGENE_DMA_RAID6_CONT);
>> +       else
>> +               dev_info(pdma->dev, "PQ is disabled in HW\n");
>> +
>> +       xgene_dma_enable(pdma);
>> +       xgene_dma_unmask_interrupts(pdma);
>> +
>> +       /* Get DMA id and version info */
>> +       val = ioread32(pdma->csr_dma + XGENE_DMA_IPBRR);
>> +
>> +       /* DMA device info */
>> +       dev_info(pdma->dev,
>> +                "X-Gene DMA v%d.%02d.%02d driver registered %d channels",
>> +                XGENE_DMA_REV_NO_RD(val), XGENE_DMA_BUS_ID_RD(val),
>> +                XGENE_DMA_DEV_ID_RD(val), XGENE_DMA_MAX_CHANNEL);
>> +}
>> +
>> +int xgene_dma_init_ring_mngr(struct xgene_dma *pdma)
>> +{
>> +       if (ioread32(pdma->csr_ring + XGENE_DMA_RING_CLKEN) &&
>> +           (!ioread32(pdma->csr_ring + XGENE_DMA_RING_SRST)))
>> +               return 0;
>> +
>> +       iowrite32(0x3, pdma->csr_ring + XGENE_DMA_RING_CLKEN);
>> +       iowrite32(0x0, pdma->csr_ring + XGENE_DMA_RING_SRST);
>> +
>> +       /* Bring up memory */
>> +       iowrite32(0x0, pdma->csr_ring + XGENE_DMA_RING_MEM_RAM_SHUTDOWN);
>> +
>> +       /* Force a barrier */
>> +       ioread32(pdma->csr_ring + XGENE_DMA_RING_MEM_RAM_SHUTDOWN);
>> +
>> +       /* reset may take up to 1ms */
>> +       usleep_range(1000, 1100);
>> +
>> +       if (ioread32(pdma->csr_ring + XGENE_DMA_RING_BLK_MEM_RDY)
>> +               != XGENE_DMA_RING_BLK_MEM_RDY_VAL) {
>> +               dev_err(pdma->dev,
>> +                       "Failed to release ring mngr memory from shutdown\n");
>> +               return -ENODEV;
>> +       }
>> +
>> +       /* program threshold set 1 and all hysteresis */
>> +       iowrite32(XGENE_DMA_RING_THRESLD0_SET1_VAL,
>> +                 pdma->csr_ring + XGENE_DMA_RING_THRESLD0_SET1);
>> +       iowrite32(XGENE_DMA_RING_THRESLD1_SET1_VAL,
>> +                 pdma->csr_ring + XGENE_DMA_RING_THRESLD1_SET1);
>> +       iowrite32(XGENE_DMA_RING_HYSTERESIS_VAL,
>> +                 pdma->csr_ring + XGENE_DMA_RING_HYSTERESIS);
>> +
>> +       /* Enable QPcore and assign error queue */
>> +       iowrite32(XGENE_DMA_RING_ENABLE,
>> +                 pdma->csr_ring + XGENE_DMA_RING_CONFIG);
>> +
>> +       return 0;
>> +}
>> +
>> +static int xgene_dma_init_mem(struct xgene_dma *pdma)
>> +{
>> +       int ret;
>> +
>> +       ret = xgene_dma_init_ring_mngr(pdma);
>> +       if (ret)
>> +               return ret;
>> +
>> +       /* Bring up memory */
>> +       iowrite32(0x0, pdma->csr_dma + XGENE_DMA_MEM_RAM_SHUTDOWN);
>> +
>> +       /* Force a barrier */
>> +       ioread32(pdma->csr_dma + XGENE_DMA_MEM_RAM_SHUTDOWN);
>> +
>> +       /* reset may take up to 1ms */
>> +       usleep_range(1000, 1100);
>> +
>> +       if (ioread32(pdma->csr_dma + XGENE_DMA_BLK_MEM_RDY)
>> +               != XGENE_DMA_BLK_MEM_RDY_VAL) {
>> +               dev_err(pdma->dev,
>> +                       "Failed to release DMA memory from shutdown\n");
>> +               return -ENODEV;
>> +       }
>> +
>> +       return 0;
>> +}
>> +
>> +static int xgene_dma_request_irqs(struct xgene_dma *pdma)
>> +{
>> +       struct xgene_dma_chan *chan;
>> +       int ret, i, j;
>> +
>> +       /* Register DMA error irq */
>> +       ret = devm_request_irq(pdma->dev, pdma->err_irq, xgene_dma_err_isr,
>> +                              0, "dma_error", pdma);
>> +       if (ret) {
>> +               dev_err(pdma->dev,
>> +                       "Failed to register error IRQ %d\n", pdma->err_irq);
>> +               return ret;
>> +       }
>> +
>> +       /* Register DMA channel rx irq */
>> +       for (i = 0; i < XGENE_DMA_MAX_CHANNEL; i++) {
>> +               chan = &pdma->chan[i];
>> +               ret = devm_request_irq(chan->dev, chan->rx_irq,
>> +                                      xgene_dma_chan_ring_isr,
>> +                                      0, chan->name, chan);
>> +               if (ret) {
>> +                       chan_err(chan, "Failed to register Rx IRQ %d\n",
>> +                                chan->rx_irq);
>> +                       devm_free_irq(pdma->dev, pdma->err_irq, pdma);
>> +
>> +                       for (j = 0; j < i; j++) {
>> +                               chan = &pdma->chan[i];
>> +                               devm_free_irq(chan->dev, chan->rx_irq, chan);
>> +                       }
>> +
>> +                       return ret;
>> +               }
>> +       }
>> +
>> +       return 0;
>> +}
>> +
>> +static void xgene_dma_free_irqs(struct xgene_dma *pdma)
>> +{
>> +       struct xgene_dma_chan *chan;
>> +       int i;
>> +
>> +       /* Free DMA device error irq */
>> +       devm_free_irq(pdma->dev, pdma->err_irq, pdma);
>> +
>> +       for (i = 0; i < XGENE_DMA_MAX_CHANNEL; i++) {
>> +               chan = &pdma->chan[i];
>> +               devm_free_irq(chan->dev, chan->rx_irq, chan);
>> +       }
>> +}
>> +
>> +static void xgene_dma_set_caps(struct xgene_dma_chan *chan,
>> +                              struct dma_device *dma_dev)
>> +{
>> +       /* Initialize DMA device capability mask */
>> +       dma_cap_zero(dma_dev->cap_mask);
>> +
>> +       /* Set DMA device capability */
>> +       dma_cap_set(DMA_MEMCPY, dma_dev->cap_mask);
>> +       dma_cap_set(DMA_SG, dma_dev->cap_mask);
>> +
>> +       /* Basically here, the X-Gene SoC DMA engine channel 0 supports XOR
>> +        * and channel 1 supports XOR, PQ both. First thing here is we have
>> +        * mechanism in hw to enable/disable PQ/XOR supports on channel 1,
>> +        * we can make sure this by reading SoC Efuse register.
>> +        * Second thing, we have hw errata that if we run channel 0 and
>> +        * channel 1 simultaneously with executing XOR and PQ request,
>> +        * suddenly DMA engine hangs, So here we enable XOR on channel 0 only
>> +        * if XOR and PQ supports on channel 1 is disabled.
>> +        */
>> +       if ((chan->id == XGENE_DMA_PQ_CHANNEL) &&
>> +           is_pq_enabled(chan->pdma)) {
>> +               dma_cap_set(DMA_PQ, dma_dev->cap_mask);
>> +               dma_cap_set(DMA_XOR, dma_dev->cap_mask);
>> +       } else if ((chan->id == XGENE_DMA_XOR_CHANNEL) &&
>> +                  !is_pq_enabled(chan->pdma)) {
>> +               dma_cap_set(DMA_XOR, dma_dev->cap_mask);
>> +       }
>> +
>> +       /* Set base and prep routines */
>> +       dma_dev->dev = chan->dev;
>> +       dma_dev->device_alloc_chan_resources = xgene_dma_alloc_chan_resources;
>> +       dma_dev->device_free_chan_resources = xgene_dma_free_chan_resources;
>> +       dma_dev->device_issue_pending = xgene_dma_issue_pending;
>> +       dma_dev->device_tx_status = xgene_dma_tx_status;
>> +       dma_dev->device_prep_dma_memcpy = xgene_dma_prep_memcpy;
>> +       dma_dev->device_prep_dma_sg = xgene_dma_prep_sg;
>> +
>> +       if (dma_has_cap(DMA_XOR, dma_dev->cap_mask)) {
>> +               dma_dev->device_prep_dma_xor = xgene_dma_prep_xor;
>> +               dma_dev->max_xor = XGENE_DMA_MAX_XOR_SRC;
>> +               dma_dev->xor_align = XGENE_DMA_XOR_ALIGNMENT;
>> +       }
>> +
>> +       if (dma_has_cap(DMA_PQ, dma_dev->cap_mask)) {
>> +               dma_dev->device_prep_dma_pq = xgene_dma_prep_pq;
>> +               dma_dev->max_pq = XGENE_DMA_MAX_XOR_SRC;
>> +               dma_dev->pq_align = XGENE_DMA_XOR_ALIGNMENT;
>> +       }
>> +}
>> +
>> +static int xgene_dma_async_register(struct xgene_dma *pdma, int id)
>> +{
>> +       struct xgene_dma_chan *chan = &pdma->chan[id];
>> +       struct dma_device *dma_dev = &pdma->dma_dev[id];
>> +       int ret;
>> +
>> +       chan->dma_chan.device = dma_dev;
>> +
>> +       spin_lock_init(&chan->lock);
>> +       INIT_LIST_HEAD(&chan->ld_pending);
>> +       INIT_LIST_HEAD(&chan->ld_running);
>> +       INIT_LIST_HEAD(&chan->ld_completed);
>> +       tasklet_init(&chan->tasklet, xgene_dma_tasklet_cb,
>> +                    (unsigned long)chan);
>> +
>> +       chan->pending = 0;
>> +       chan->desc_pool = NULL;
>> +       dma_cookie_init(&chan->dma_chan);
>> +
>> +       /* Setup dma device capabilities and prep routines */
>> +       xgene_dma_set_caps(chan, dma_dev);
>> +
>> +       /* Initialize DMA device list head */
>> +       INIT_LIST_HEAD(&dma_dev->channels);
>> +       list_add_tail(&chan->dma_chan.device_node, &dma_dev->channels);
>> +
>> +       /* Register with Linux async DMA framework*/
>> +       ret = dma_async_device_register(dma_dev);
>> +       if (ret) {
>> +               chan_err(chan, "Failed to register async device %d", ret);
>> +               tasklet_kill(&chan->tasklet);
>> +
>> +               return ret;
>> +       }
>> +
>> +       /* DMA capability info */
>> +       dev_info(pdma->dev,
>> +                "%s: CAPABILITY ( %s%s%s%s)\n", dma_chan_name(&chan->dma_chan),
>> +                dma_has_cap(DMA_MEMCPY, dma_dev->cap_mask) ? "MEMCPY " : "",
>> +                dma_has_cap(DMA_SG, dma_dev->cap_mask) ? "SGCPY " : "",
>> +                dma_has_cap(DMA_XOR, dma_dev->cap_mask) ? "XOR " : "",
>> +                dma_has_cap(DMA_PQ, dma_dev->cap_mask) ? "PQ " : "");
>> +
>> +       return 0;
>> +}
>> +
>> +static int xgene_dma_init_async(struct xgene_dma *pdma)
>> +{
>> +       int ret, i, j;
>> +
>> +       for (i = 0; i < XGENE_DMA_MAX_CHANNEL ; i++) {
>> +               ret = xgene_dma_async_register(pdma, i);
>> +               if (ret) {
>> +                       for (j = 0; j < i; j++) {
>> +                               dma_async_device_unregister(&pdma->dma_dev[j]);
>> +                               tasklet_kill(&pdma->chan[j].tasklet);
>> +                       }
>> +
>> +                       return ret;
>> +               }
>> +       }
>> +
>> +       return ret;
>> +}
>> +
>> +static void xgene_dma_async_unregister(struct xgene_dma *pdma)
>> +{
>> +       int i;
>> +
>> +       for (i = 0; i < XGENE_DMA_MAX_CHANNEL; i++)
>> +               dma_async_device_unregister(&pdma->dma_dev[i]);
>> +}
>> +
>> +static void xgene_dma_init_channels(struct xgene_dma *pdma)
>> +{
>> +       struct xgene_dma_chan *chan;
>> +       int i;
>> +
>> +       pdma->ring_num = XGENE_DMA_RING_NUM;
>> +
>> +       for (i = 0; i < XGENE_DMA_MAX_CHANNEL; i++) {
>> +               chan = &pdma->chan[i];
>> +               chan->dev = pdma->dev;
>> +               chan->pdma = pdma;
>> +               chan->id = i;
>> +               sprintf(chan->name, "dmachan%d", chan->id);
>> +       }
>> +}
>> +
>> +static int xgene_dma_get_resources(struct platform_device *pdev,
>> +                                  struct xgene_dma *pdma)
>> +{
>> +       struct resource *res;
>> +       int irq, i;
>> +
>> +       /* Get DMA csr region */
>> +       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> +       if (!res) {
>> +               dev_err(&pdev->dev, "Failed to get csr region\n");
>> +               return -ENXIO;
>> +       }
>> +
>> +       pdma->csr_dma = devm_ioremap(&pdev->dev, res->start,
>> +                                    resource_size(res));
>> +       if (IS_ERR(pdma->csr_dma)) {
>> +               dev_err(&pdev->dev, "Failed to ioremap csr region");
>> +               return PTR_ERR(pdma->csr_dma);
>> +       }
>> +
>> +       /* Get DMA ring csr region */
>> +       res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
>> +       if (!res) {
>> +               dev_err(&pdev->dev, "Failed to get ring csr region\n");
>> +               return -ENXIO;
>> +       }
>> +
>> +       pdma->csr_ring =  devm_ioremap(&pdev->dev, res->start,
>> +                                      resource_size(res));
>> +       if (IS_ERR(pdma->csr_ring)) {
>> +               dev_err(&pdev->dev, "Failed to ioremap ring csr region");
>> +               return PTR_ERR(pdma->csr_ring);
>> +       }
>> +
>> +       /* Get DMA ring cmd csr region */
>> +       res = platform_get_resource(pdev, IORESOURCE_MEM, 2);
>> +       if (!res) {
>> +               dev_err(&pdev->dev, "Failed to get ring cmd csr region\n");
>> +               return -ENXIO;
>> +       }
>> +
>> +       pdma->csr_ring_cmd = devm_ioremap(&pdev->dev, res->start,
>> +                                         resource_size(res));
>> +       if (IS_ERR(pdma->csr_ring_cmd)) {
>> +               dev_err(&pdev->dev, "Failed to ioremap ring cmd csr region");
>> +               return PTR_ERR(pdma->csr_ring_cmd);
>> +       }
>> +
>> +       /* Get efuse csr region */
>> +       res = platform_get_resource(pdev, IORESOURCE_MEM, 3);
>> +       if (!res) {
>> +               dev_err(&pdev->dev, "Failed to get efuse csr region\n");
>> +               return -ENXIO;
>> +       }
>> +
>> +       pdma->csr_efuse = devm_ioremap(&pdev->dev, res->start,
>> +                                      resource_size(res));
>> +       if (IS_ERR(pdma->csr_efuse)) {
>> +               dev_err(&pdev->dev, "Failed to ioremap efuse csr region");
>> +               return PTR_ERR(pdma->csr_efuse);
>> +       }
>> +
>> +       /* Get DMA error interrupt */
>> +       irq = platform_get_irq(pdev, 0);
>> +       if (irq <= 0) {
>> +               dev_err(&pdev->dev, "Failed to get Error IRQ\n");
>> +               return -ENXIO;
>> +       }
>> +
>> +       pdma->err_irq = irq;
>> +
>> +       /* Get DMA Rx ring descriptor interrupts for all DMA channels */
>> +       for (i = 1; i <= XGENE_DMA_MAX_CHANNEL; i++) {
>> +               irq = platform_get_irq(pdev, i);
>> +               if (irq <= 0) {
>> +                       dev_err(&pdev->dev, "Failed to get Rx IRQ\n");
>> +                       return -ENXIO;
>> +               }
>> +
>> +               pdma->chan[i - 1].rx_irq = irq;
>> +       }
>> +
>> +       return 0;
>> +}
>> +
>> +static int xgene_dma_probe(struct platform_device *pdev)
>> +{
>> +       struct xgene_dma *pdma;
>> +       int ret, i;
>> +
>> +       pdma = devm_kzalloc(&pdev->dev, sizeof(*pdma), GFP_KERNEL);
>> +       if (!pdma)
>> +               return -ENOMEM;
>> +
>> +       pdma->dev = &pdev->dev;
>> +       platform_set_drvdata(pdev, pdma);
>> +
>> +       ret = xgene_dma_get_resources(pdev, pdma);
>> +       if (ret)
>> +               return ret;
>> +
>> +       pdma->clk = devm_clk_get(&pdev->dev, NULL);
>> +       if (IS_ERR(pdma->clk)) {
>> +               dev_err(&pdev->dev, "Failed to get clk\n");
>> +               return PTR_ERR(pdma->clk);
>> +       }
>> +
>> +       /* Enable clk before accessing registers */
>> +       ret = clk_prepare_enable(pdma->clk);
>> +       if (ret) {
>> +               dev_err(&pdev->dev, "Failed to enable clk %d\n", ret);
>> +               return ret;
>> +       }
>> +
>> +       /* Remove DMA RAM out of shutdown */
>> +       ret = xgene_dma_init_mem(pdma);
>> +       if (ret)
>> +               goto err_clk_enable;
>> +
>> +       ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(42));
>> +       if (ret) {
>> +               dev_err(&pdev->dev, "No usable DMA configuration\n");
>> +               goto err_dma_mask;
>> +       }
>> +
>> +       /* Initialize DMA channels software state */
>> +       xgene_dma_init_channels(pdma);
>> +
>> +       /* Configue DMA rings */
>> +       ret = xgene_dma_init_rings(pdma);
>> +       if (ret)
>> +               goto err_clk_enable;
>> +
>> +       ret = xgene_dma_request_irqs(pdma);
>> +       if (ret)
>> +               goto err_request_irq;
>> +
>> +       /* Configure and enable DMA engine */
>> +       xgene_dma_init_hw(pdma);
>> +
>> +       /* Register DMA device with linux async framework */
>> +       ret = xgene_dma_init_async(pdma);
>> +       if (ret)
>> +               goto err_async_init;
>> +
>> +       return 0;
>> +
>> +err_async_init:
>> +       xgene_dma_free_irqs(pdma);
>> +
>> +err_request_irq:
>> +       for (i = 0; i < XGENE_DMA_MAX_CHANNEL; i++)
>> +               xgene_dma_delete_chan_rings(&pdma->chan[i]);
>> +
>> +err_dma_mask:
>> +err_clk_enable:
>> +       clk_disable_unprepare(pdma->clk);
>> +
>> +       return ret;
>> +}
>> +
>> +static int xgene_dma_remove(struct platform_device *pdev)
>> +{
>> +       struct xgene_dma *pdma = platform_get_drvdata(pdev);
>> +       struct xgene_dma_chan *chan;
>> +       int i;
>> +
>> +       xgene_dma_async_unregister(pdma);
>> +
>> +       /* Mask interrupts and disable DMA engine */
>> +       xgene_dma_mask_interrupts(pdma);
>> +       xgene_dma_disable(pdma);
>> +       xgene_dma_free_irqs(pdma);
>> +
>> +       for (i = 0; i < XGENE_DMA_MAX_CHANNEL; i++) {
>> +               chan = &pdma->chan[i];
>> +               tasklet_kill(&chan->tasklet);
>> +               xgene_dma_delete_chan_rings(chan);
>> +       }
>> +
>> +       clk_disable_unprepare(pdma->clk);
>> +
>> +       return 0;
>> +}
>> +
>> +static const struct of_device_id xgene_dma_of_match_ptr[] = {
>> +       {.compatible = "apm,xgene-storm-dma",},
>> +       {},
>> +};
>> +MODULE_DEVICE_TABLE(of, xgene_dma_of_match_ptr);
>> +
>> +static struct platform_driver xgene_dma_driver = {
>> +       .probe = xgene_dma_probe,
>> +       .remove = xgene_dma_remove,
>> +       .driver = {
>> +               .name = "X-Gene-DMA",
>> +               .owner = THIS_MODULE,
>> +               .of_match_table = xgene_dma_of_match_ptr,
>> +       },
>> +};
>> +
>> +module_platform_driver(xgene_dma_driver);
>> +
>> +MODULE_DESCRIPTION("APM X-Gene SoC DMA driver");
>> +MODULE_AUTHOR("Rameshwar Prasad Sahu <[e-mail]>");
>> +MODULE_AUTHOR("Loc Ho <[e-mail]>");
>> +MODULE_LICENSE("GPL");
>> +MODULE_VERSION("1.0");
>> --
>> 1.8.2.1
>>
>
>
> Any comments on above patch....

Pinging again...

Thanks,
Ram
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Rameshwar Prasad Sahu March 30, 2015, 9:05 a.m. UTC | #3

Hi Vinod,

On Mon, Mar 23, 2015 at 4:37 PM, Rameshwar Sahu <[e-mail]> wrote:
> Hi Vinod,
>
> On Thu, Mar 19, 2015 at 1:47 PM, Rameshwar Sahu <[e-mail]> wrote:
>> Hi Vinod,
>>
>> On Wed, Mar 18, 2015 at 7:17 PM, Rameshwar Prasad Sahu <[e-mail]> wrote:
>>> This patch implements the APM X-Gene SoC DMA engine driver. The APM X-Gene
>>> SoC DMA engine consists of 4 DMA channels for performing DMA operations.
>>> These DMA operations include memory copy, scatter-gather memory copy,
>>> raid5 xor, and raid6 p+q offloading.
>>>
>>> Signed-off-by: Rameshwar Prasad Sahu <[e-mail]>
>>> Signed-off-by: Loc Ho <[e-mail]>
>>> ---
>>>  drivers/dma/Kconfig     |    8 +
>>>  drivers/dma/Makefile    |    1 +
>>>  drivers/dma/xgene-dma.c | 2090 +++++++++++++++++++++++++++++++++++++++++++++++
>>>  3 files changed, 2099 insertions(+)
>>>  create mode 100755 drivers/dma/xgene-dma.c
>>>
>>> diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
>>> index a874b6e..a271346 100644
>>> --- a/drivers/dma/Kconfig
>>> +++ b/drivers/dma/Kconfig
>>> @@ -425,6 +425,14 @@ config IMG_MDC_DMA
>>>         help
>>>           Enable support for the IMG multi-threaded DMA controller (MDC).
>>>
>>> +config XGENE_DMA
>>> +       tristate "APM X-Gene DMA support"
>>> +       select DMA_ENGINE
>>> +       select DMA_ENGINE_RAID
>>> +       select ASYNC_TX_ENABLE_CHANNEL_SWITCH
>>> +       help
>>> +         Enable support for the APM X-Gene SoC DMA engine.
>>> +
>>>  config DMA_ENGINE
>>>         bool
>>>
>>> diff --git a/drivers/dma/Makefile b/drivers/dma/Makefile
>>> index f915f61..06c1576 100644
>>> --- a/drivers/dma/Makefile
>>> +++ b/drivers/dma/Makefile
>>> @@ -51,3 +51,4 @@ obj-$(CONFIG_INTEL_MIC_X100_DMA) += mic_x100_dma.o
>>>  obj-$(CONFIG_NBPFAXI_DMA) += nbpfaxi.o
>>>  obj-$(CONFIG_DMA_SUN6I) += sun6i-dma.o
>>>  obj-$(CONFIG_IMG_MDC_DMA) += img-mdc-dma.o
>>> +obj-$(CONFIG_XGENE_DMA) += xgene-dma.o
>>> diff --git a/drivers/dma/xgene-dma.c b/drivers/dma/xgene-dma.c
>>> new file mode 100755
>>> index 0000000..2383528
>>> --- /dev/null
>>> +++ b/drivers/dma/xgene-dma.c
>>> @@ -0,0 +1,2090 @@
>>> +/*
>>> + * Applied Micro X-Gene SoC DMA engine Driver
>>> + *
>>> + * Copyright (c) 2015, Applied Micro Circuits Corporation
>>> + * Authors: Rameshwar Prasad Sahu <[e-mail]>
>>> + *         Loc Ho <[e-mail]>
>>> + *
>>> + * This program is free software; you can redistribute  it and/or modify it
>>> + * under  the terms of  the GNU General  Public License as published by the
>>> + * Free Software Foundation;  either version 2 of the  License, or (at your
>>> + * option) any later version.
>>> + *
>>> + * This program is distributed in the hope that it will be useful,
>>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
>>> + * GNU General Public License for more details.
>>> + *
>>> + * You should have received a copy of the GNU General Public License
>>> + * along with this program.  If not, see <http://www.gnu.org/licenses/>.
>>> + *
>>> + * NOTE: PM support is currently not available.
>>> + */
>>> +
>>> +#include <linux/clk.h>
>>> +#include <linux/delay.h>
>>> +#include <linux/dma-mapping.h>
>>> +#include <linux/dmaengine.h>
>>> +#include <linux/dmapool.h>
>>> +#include <linux/interrupt.h>
>>> +#include <linux/io.h>
>>> +#include <linux/module.h>
>>> +#include <linux/of_device.h>
>>> +
>>> +#include "dmaengine.h"
>>> +
>>> +/* X-Gene DMA ring csr registers and bit definations */
>>> +#define XGENE_DMA_RING_CONFIG                  0x04
>>> +#define XGENE_DMA_RING_ENABLE                  BIT(31)
>>> +#define XGENE_DMA_RING_ID                      0x08
>>> +#define XGENE_DMA_RING_ID_SETUP(v)             ((v) | BIT(31))
>>> +#define XGENE_DMA_RING_ID_BUF                  0x0C
>>> +#define XGENE_DMA_RING_ID_BUF_SETUP(v)         (((v) << 9) | BIT(21))
>>> +#define XGENE_DMA_RING_THRESLD0_SET1           0x30
>>> +#define XGENE_DMA_RING_THRESLD0_SET1_VAL       0X64
>>> +#define XGENE_DMA_RING_THRESLD1_SET1           0x34
>>> +#define XGENE_DMA_RING_THRESLD1_SET1_VAL       0xC8
>>> +#define XGENE_DMA_RING_HYSTERESIS              0x68
>>> +#define XGENE_DMA_RING_HYSTERESIS_VAL          0xFFFFFFFF
>>> +#define XGENE_DMA_RING_STATE                   0x6C
>>> +#define XGENE_DMA_RING_STATE_WR_BASE           0x70
>>> +#define XGENE_DMA_RING_NE_INT_MODE             0x017C
>>> +#define XGENE_DMA_RING_NE_INT_MODE_SET(m, v)   \
>>> +       ((m) = ((m) & ~BIT(31 - (v))) | BIT(31 - (v)))
>>> +#define XGENE_DMA_RING_NE_INT_MODE_RESET(m, v) \
>>> +       ((m) &= (~BIT(31 - (v))))
>>> +#define XGENE_DMA_RING_CLKEN                   0xC208
>>> +#define XGENE_DMA_RING_SRST                    0xC200
>>> +#define XGENE_DMA_RING_MEM_RAM_SHUTDOWN                0xD070
>>> +#define XGENE_DMA_RING_BLK_MEM_RDY             0xD074
>>> +#define XGENE_DMA_RING_BLK_MEM_RDY_VAL         0xFFFFFFFF
>>> +#define XGENE_DMA_RING_DESC_CNT(v)             (((v) & 0x0001FFFE) >> 1)
>>> +#define XGENE_DMA_RING_ID_GET(owner, num)      (((owner) << 6) | (num))
>>> +#define XGENE_DMA_RING_DST_ID(v)               ((1 << 10) | (v))
>>> +#define XGENE_DMA_RING_CMD_OFFSET              0x2C
>>> +#define XGENE_DMA_RING_CMD_BASE_OFFSET(v)      ((v) << 6)
>>> +#define XGENE_DMA_RING_COHERENT_SET(m)         \
>>> +       (((u32 *)(m))[2] |= BIT(4))
>>> +#define XGENE_DMA_RING_ADDRL_SET(m, v)         \
>>> +       (((u32 *)(m))[2] |= (((v) >> 8) << 5))
>>> +#define XGENE_DMA_RING_ADDRH_SET(m, v)         \
>>> +       (((u32 *)(m))[3] |= ((v) >> 35))
>>> +#define XGENE_DMA_RING_ACCEPTLERR_SET(m)       \
>>> +       (((u32 *)(m))[3] |= BIT(19))
>>> +#define XGENE_DMA_RING_SIZE_SET(m, v)          \
>>> +       (((u32 *)(m))[3] |= ((v) << 23))
>>> +#define XGENE_DMA_RING_RECOMBBUF_SET(m)                \
>>> +       (((u32 *)(m))[3] |= BIT(27))
>>> +#define XGENE_DMA_RING_RECOMTIMEOUTL_SET(m)    \
>>> +       (((u32 *)(m))[3] |= (0x7 << 28))
>>> +#define XGENE_DMA_RING_RECOMTIMEOUTH_SET(m)    \
>>> +       (((u32 *)(m))[4] |= 0x3)
>>> +#define XGENE_DMA_RING_SELTHRSH_SET(m)         \
>>> +       (((u32 *)(m))[4] |= BIT(3))
>>> +#define XGENE_DMA_RING_TYPE_SET(m, v)          \
>>> +       (((u32 *)(m))[4] |= ((v) << 19))
>>> +
>>> +/* X-Gene DMA device csr registers and bit definitions */
>>> +#define XGENE_DMA_IPBRR                                0x0
>>> +#define XGENE_DMA_DEV_ID_RD(v)                 ((v) & 0x00000FFF)
>>> +#define XGENE_DMA_BUS_ID_RD(v)                 (((v) >> 12) & 3)
>>> +#define XGENE_DMA_REV_NO_RD(v)                 (((v) >> 14) & 3)
>>> +#define XGENE_DMA_GCR                          0x10
>>> +#define XGENE_DMA_CH_SETUP(v)                  \
>>> +       ((v) = ((v) & ~0x000FFFFF) | 0x000AAFFF)
>>> +#define XGENE_DMA_ENABLE(v)                    ((v) |= BIT(31))
>>> +#define XGENE_DMA_DISABLE(v)                   ((v) &= ~BIT(31))
>>> +#define XGENE_DMA_RAID6_CONT                   0x14
>>> +#define XGENE_DMA_RAID6_MULTI_CTRL(v)          ((v) << 24)
>>> +#define XGENE_DMA_INT                          0x70
>>> +#define XGENE_DMA_INT_MASK                     0x74
>>> +#define XGENE_DMA_INT_ALL_MASK                 0xFFFFFFFF
>>> +#define XGENE_DMA_INT_ALL_UNMASK               0x0
>>> +#define XGENE_DMA_INT_MASK_SHIFT               0x14
>>> +#define XGENE_DMA_RING_INT0_MASK               0x90A0
>>> +#define XGENE_DMA_RING_INT1_MASK               0x90A8
>>> +#define XGENE_DMA_RING_INT2_MASK               0x90B0
>>> +#define XGENE_DMA_RING_INT3_MASK               0x90B8
>>> +#define XGENE_DMA_RING_INT4_MASK               0x90C0
>>> +#define XGENE_DMA_CFG_RING_WQ_ASSOC            0x90E0
>>> +#define XGENE_DMA_ASSOC_RING_MNGR1             0xFFFFFFFF
>>> +#define XGENE_DMA_MEM_RAM_SHUTDOWN             0xD070
>>> +#define XGENE_DMA_BLK_MEM_RDY                  0xD074
>>> +#define XGENE_DMA_BLK_MEM_RDY_VAL              0xFFFFFFFF
>>> +
>>> +/* X-Gene SoC EFUSE csr register and bit defination */
>>> +#define XGENE_SOC_JTAG1_SHADOW                 0x18
>>> +#define XGENE_DMA_PQ_DISABLE_MASK              BIT(13)
>>> +
>>> +/* X-Gene DMA Descriptor format */
>>> +#define XGENE_DMA_DESC_NV_BIT                  BIT_ULL(50)
>>> +#define XGENE_DMA_DESC_IN_BIT                  BIT_ULL(55)
>>> +#define XGENE_DMA_DESC_C_BIT                   BIT_ULL(63)
>>> +#define XGENE_DMA_DESC_DR_BIT                  BIT_ULL(61)
>>> +#define XGENE_DMA_DESC_ELERR_POS               46
>>> +#define XGENE_DMA_DESC_RTYPE_POS               56
>>> +#define XGENE_DMA_DESC_LERR_POS                        60
>>> +#define XGENE_DMA_DESC_FLYBY_POS               4
>>> +#define XGENE_DMA_DESC_BUFLEN_POS              48
>>> +#define XGENE_DMA_DESC_HOENQ_NUM_POS           48
>>> +
>>> +#define XGENE_DMA_DESC_NV_SET(m)               \
>>> +       (((u64 *)(m))[0] |= XGENE_DMA_DESC_NV_BIT)
>>> +#define XGENE_DMA_DESC_IN_SET(m)               \
>>> +       (((u64 *)(m))[0] |= XGENE_DMA_DESC_IN_BIT)
>>> +#define XGENE_DMA_DESC_RTYPE_SET(m, v)         \
>>> +       (((u64 *)(m))[0] |= ((u64)(v) << XGENE_DMA_DESC_RTYPE_POS))
>>> +#define XGENE_DMA_DESC_BUFADDR_SET(m, v)       \
>>> +       (((u64 *)(m))[0] |= (v))
>>> +#define XGENE_DMA_DESC_BUFLEN_SET(m, v)                \
>>> +       (((u64 *)(m))[0] |= ((u64)(v) << XGENE_DMA_DESC_BUFLEN_POS))
>>> +#define XGENE_DMA_DESC_C_SET(m)                        \
>>> +       (((u64 *)(m))[1] |= XGENE_DMA_DESC_C_BIT)
>>> +#define XGENE_DMA_DESC_FLYBY_SET(m, v)         \
>>> +       (((u64 *)(m))[2] |= ((v) << XGENE_DMA_DESC_FLYBY_POS))
>>> +#define XGENE_DMA_DESC_MULTI_SET(m, v, i)      \
>>> +       (((u64 *)(m))[2] |= ((u64)(v) << (((i) + 1) * 8)))
>>> +#define XGENE_DMA_DESC_DR_SET(m)               \
>>> +       (((u64 *)(m))[2] |= XGENE_DMA_DESC_DR_BIT)
>>> +#define XGENE_DMA_DESC_DST_ADDR_SET(m, v)      \
>>> +       (((u64 *)(m))[3] |= (v))
>>> +#define XGENE_DMA_DESC_H0ENQ_NUM_SET(m, v)     \
>>> +       (((u64 *)(m))[3] |= ((u64)(v) << XGENE_DMA_DESC_HOENQ_NUM_POS))
>>> +#define XGENE_DMA_DESC_ELERR_RD(m)             \
>>> +       (((m) >> XGENE_DMA_DESC_ELERR_POS) & 0x3)
>>> +#define XGENE_DMA_DESC_LERR_RD(m)              \
>>> +       (((m) >> XGENE_DMA_DESC_LERR_POS) & 0x7)
>>> +#define XGENE_DMA_DESC_STATUS(elerr, lerr)     \
>>> +       (((elerr) << 4) | (lerr))
>>> +
>>> +/* X-Gene DMA descriptor empty s/w signature */
>>> +#define XGENE_DMA_DESC_EMPTY_INDEX             0
>>> +#define XGENE_DMA_DESC_EMPTY_SIGNATURE         ~0ULL
>>> +#define XGENE_DMA_DESC_SET_EMPTY(m)            \
>>> +       (((u64 *)(m))[XGENE_DMA_DESC_EMPTY_INDEX] =     \
>>> +        XGENE_DMA_DESC_EMPTY_SIGNATURE)
>>> +#define XGENE_DMA_DESC_IS_EMPTY(m)             \
>>> +       (((u64 *)(m))[XGENE_DMA_DESC_EMPTY_INDEX] ==    \
>>> +        XGENE_DMA_DESC_EMPTY_SIGNATURE)
>>> +
>>> +/* X-Gene DMA configurable parameters defines */
>>> +#define XGENE_DMA_RING_NUM             512
>>> +#define XGENE_DMA_BUFNUM               0x0
>>> +#define XGENE_DMA_CPU_BUFNUM           0x18
>>> +#define XGENE_DMA_RING_OWNER_DMA       0x03
>>> +#define XGENE_DMA_RING_OWNER_CPU       0x0F
>>> +#define XGENE_DMA_RING_TYPE_REGULAR    0x01
>>> +#define XGENE_DMA_RING_WQ_DESC_SIZE    32      /* 32 Bytes */
>>> +#define XGENE_DMA_RING_NUM_CONFIG      5
>>> +#define XGENE_DMA_MAX_CHANNEL          4
>>> +#define XGENE_DMA_XOR_CHANNEL          0
>>> +#define XGENE_DMA_PQ_CHANNEL           1
>>> +#define XGENE_DMA_MAX_BYTE_CNT         0x4000  /* 16 KB */
>>> +#define XGENE_DMA_MAX_64B_DESC_BYTE_CNT        0x14000 /* 80 KB */
>>> +#define XGENE_DMA_XOR_ALIGNMENT                6       /* 64 Bytes */
>>> +#define XGENE_DMA_MAX_XOR_SRC          5
>>> +#define XGENE_DMA_16K_BUFFER_LEN_CODE  0x0
>>> +#define XGENE_DMA_INVALID_LEN_CODE     0x7800
>>> +
>>> +/* X-Gene DMA descriptor error codes */
>>> +#define ERR_DESC_AXI                   0x01
>>> +#define ERR_BAD_DESC                   0x02
>>> +#define ERR_READ_DATA_AXI              0x03
>>> +#define ERR_WRITE_DATA_AXI             0x04
>>> +#define ERR_FBP_TIMEOUT                        0x05
>>> +#define ERR_ECC                                0x06
>>> +#define ERR_DIFF_SIZE                  0x08
>>> +#define ERR_SCT_GAT_LEN                        0x09
>>> +#define ERR_CRC_ERR                    0x11
>>> +#define ERR_CHKSUM                     0x12
>>> +#define ERR_DIF                                0x13
>>> +
>>> +/* X-Gene DMA error interrupt codes */
>>> +#define ERR_DIF_SIZE_INT               0x0
>>> +#define ERR_GS_ERR_INT                 0x1
>>> +#define ERR_FPB_TIMEO_INT              0x2
>>> +#define ERR_WFIFO_OVF_INT              0x3
>>> +#define ERR_RFIFO_OVF_INT              0x4
>>> +#define ERR_WR_TIMEO_INT               0x5
>>> +#define ERR_RD_TIMEO_INT               0x6
>>> +#define ERR_WR_ERR_INT                 0x7
>>> +#define ERR_RD_ERR_INT                 0x8
>>> +#define ERR_BAD_DESC_INT               0x9
>>> +#define ERR_DESC_DST_INT               0xA
>>> +#define ERR_DESC_SRC_INT               0xB
>>> +
>>> +/* X-Gene DMA flyby operation code */
>>> +#define FLYBY_2SRC_XOR                 0x8
>>> +#define FLYBY_3SRC_XOR                 0x9
>>> +#define FLYBY_4SRC_XOR                 0xA
>>> +#define FLYBY_5SRC_XOR                 0xB
>>> +
>>> +/* X-Gene DMA SW descriptor flags */
>>> +#define XGENE_DMA_FLAG_64B_DESC                BIT(0)
>>> +
>>> +/* Define to dump X-Gene DMA descriptor */
>>> +#define XGENE_DMA_DESC_DUMP(desc, m)   \
>>> +       print_hex_dump(KERN_ERR, (m),   \
>>> +                       DUMP_PREFIX_ADDRESS, 16, 8, (desc), 32, 0)
>>> +
>>> +#define to_dma_desc_sw(tx)             \
>>> +       container_of(tx, struct xgene_dma_desc_sw, tx)
>>> +#define to_dma_chan(dchan)             \
>>> +       container_of(dchan, struct xgene_dma_chan, dma_chan)
>>> +
>>> +#define chan_dbg(chan, fmt, arg...)    \
>>> +       dev_dbg(chan->dev, "%s: " fmt, chan->name, ##arg)
>>> +#define chan_err(chan, fmt, arg...)    \
>>> +       dev_err(chan->dev, "%s: " fmt, chan->name, ##arg)
>>> +
>>> +struct xgene_dma_desc_hw {
>>> +       u64 m0;
>>> +       u64 m1;
>>> +       u64 m2;
>>> +       u64 m3;
>>> +};
>>> +
>>> +enum xgene_dma_ring_cfgsize {
>>> +       XGENE_DMA_RING_CFG_SIZE_512B,
>>> +       XGENE_DMA_RING_CFG_SIZE_2KB,
>>> +       XGENE_DMA_RING_CFG_SIZE_16KB,
>>> +       XGENE_DMA_RING_CFG_SIZE_64KB,
>>> +       XGENE_DMA_RING_CFG_SIZE_512KB,
>>> +       XGENE_DMA_RING_CFG_SIZE_INVALID
>>> +};
>>> +
>>> +struct xgene_dma_ring {
>>> +       struct xgene_dma *pdma;
>>> +       u8 buf_num;
>>> +       u16 id;
>>> +       u16 num;
>>> +       u16 head;
>>> +       u16 owner;
>>> +       u16 slots;
>>> +       u16 dst_ring_num;
>>> +       u32 size;
>>> +       void __iomem *cmd;
>>> +       void __iomem *cmd_base;
>>> +       dma_addr_t desc_paddr;
>>> +       u32 state[XGENE_DMA_RING_NUM_CONFIG];
>>> +       enum xgene_dma_ring_cfgsize cfgsize;
>>> +       union {
>>> +               void *desc_vaddr;
>>> +               struct xgene_dma_desc_hw *desc_hw;
>>> +       };
>>> +};
>>> +
>>> +struct xgene_dma_desc_sw {
>>> +       struct xgene_dma_desc_hw desc1;
>>> +       struct xgene_dma_desc_hw desc2;
>>> +       u32 flags;
>>> +       struct list_head node;
>>> +       struct list_head tx_list;
>>> +       struct dma_async_tx_descriptor tx;
>>> +};
>>> +
>>> +/**
>>> + * struct xgene_dma_chan - internal representation of an X-Gene DMA channel
>>> + * @dma_chan: dmaengine channel object member
>>> + * @pdma: X-Gene DMA device structure reference
>>> + * @dev: struct device reference for dma mapping api
>>> + * @id: raw id of this channel
>>> + * @rx_irq: channel IRQ
>>> + * @name: name of X-Gene DMA channel
>>> + * @lock: serializes enqueue/dequeue operations to the descriptor pool
>>> + * @pending: number of transaction request pushed to DMA controller for
>>> + *     execution, but still waiting for completion,
>>> + * @max_outstanding: max number of outstanding request we can push to channel
>>> + * @ld_pending: descriptors which are queued to run, but have not yet been
>>> + *     submitted to the hardware for execution
>>> + * @ld_running: descriptors which are currently being executing by the hardware
>>> + * @ld_completed: descriptors which have finished execution by the hardware.
>>> + *     These descriptors have already had their cleanup actions run. They
>>> + *     are waiting for the ACK bit to be set by the async tx API.
>>> + * @desc_pool: descriptor pool for DMA operations
>>> + * @tasklet: bottom half where all completed descriptors cleans
>>> + * @tx_ring: transmit ring descriptor that we use to prepare actual
>>> + *     descriptors for further executions
>>> + * @rx_ring: receive ring descriptor that we use to get completed DMA
>>> + *     descriptors during cleanup time
>>> + */
>>> +struct xgene_dma_chan {
>>> +       struct dma_chan dma_chan;
>>> +       struct xgene_dma *pdma;
>>> +       struct device *dev;
>>> +       int id;
>>> +       int rx_irq;
>>> +       char name[8];
>>> +       spinlock_t lock;
>>> +       int pending;
>>> +       int max_outstanding;
>>> +       struct list_head ld_pending;
>>> +       struct list_head ld_running;
>>> +       struct list_head ld_completed;
>>> +       struct dma_pool *desc_pool;
>>> +       struct tasklet_struct tasklet;
>>> +       struct xgene_dma_ring tx_ring;
>>> +       struct xgene_dma_ring rx_ring;
>>> +};
>>> +
>>> +/**
>>> + * struct xgene_dma - internal representation of an X-Gene DMA device
>>> + * @err_irq: DMA error irq number
>>> + * @ring_num: start id number for DMA ring
>>> + * @csr_dma: base for DMA register access
>>> + * @csr_ring: base for DMA ring register access
>>> + * @csr_ring_cmd: base for DMA ring command register access
>>> + * @csr_efuse: base for efuse register access
>>> + * @dma_dev: embedded struct dma_device
>>> + * @chan: reference to X-Gene DMA channels
>>> + */
>>> +struct xgene_dma {
>>> +       struct device *dev;
>>> +       struct clk *clk;
>>> +       int err_irq;
>>> +       int ring_num;
>>> +       void __iomem *csr_dma;
>>> +       void __iomem *csr_ring;
>>> +       void __iomem *csr_ring_cmd;
>>> +       void __iomem *csr_efuse;
>>> +       struct dma_device dma_dev[XGENE_DMA_MAX_CHANNEL];
>>> +       struct xgene_dma_chan chan[XGENE_DMA_MAX_CHANNEL];
>>> +};
>>> +
>>> +static const char * const xgene_dma_desc_err[] = {
>>> +       [ERR_DESC_AXI] = "AXI error when reading src/dst link list",
>>> +       [ERR_BAD_DESC] = "ERR or El_ERR fields not set to zero in desc",
>>> +       [ERR_READ_DATA_AXI] = "AXI error when reading data",
>>> +       [ERR_WRITE_DATA_AXI] = "AXI error when writing data",
>>> +       [ERR_FBP_TIMEOUT] = "Timeout on bufpool fetch",
>>> +       [ERR_ECC] = "ECC double bit error",
>>> +       [ERR_DIFF_SIZE] = "Bufpool too small to hold all the DIF result",
>>> +       [ERR_SCT_GAT_LEN] = "Gather and scatter data length not same",
>>> +       [ERR_CRC_ERR] = "CRC error",
>>> +       [ERR_CHKSUM] = "Checksum error",
>>> +       [ERR_DIF] = "DIF error",
>>> +};
>>> +
>>> +static const char * const xgene_dma_err[] = {
>>> +       [ERR_DIF_SIZE_INT] = "DIF size error",
>>> +       [ERR_GS_ERR_INT] = "Gather scatter not same size error",
>>> +       [ERR_FPB_TIMEO_INT] = "Free pool time out error",
>>> +       [ERR_WFIFO_OVF_INT] = "Write FIFO over flow error",
>>> +       [ERR_RFIFO_OVF_INT] = "Read FIFO over flow error",
>>> +       [ERR_WR_TIMEO_INT] = "Write time out error",
>>> +       [ERR_RD_TIMEO_INT] = "Read time out error",
>>> +       [ERR_WR_ERR_INT] = "HBF bus write error",
>>> +       [ERR_RD_ERR_INT] = "HBF bus read error",
>>> +       [ERR_BAD_DESC_INT] = "Ring descriptor HE0 not set error",
>>> +       [ERR_DESC_DST_INT] = "HFB reading dst link address error",
>>> +       [ERR_DESC_SRC_INT] = "HFB reading src link address error",
>>> +};
>>> +
>>> +static bool is_pq_enabled(struct xgene_dma *pdma)
>>> +{
>>> +       u32 val;
>>> +
>>> +       val = ioread32(pdma->csr_efuse + XGENE_SOC_JTAG1_SHADOW);
>>> +       return !(val & XGENE_DMA_PQ_DISABLE_MASK);
>>> +}
>>> +
>>> +static void xgene_dma_cpu_to_le64(u64 *desc, int count)
>>> +{
>>> +       int i;
>>> +
>>> +       for (i = 0; i < count; i++)
>>> +               desc[i] = cpu_to_le64(desc[i]);
>>> +}
>>> +
>>> +static u16 xgene_dma_encode_len(u32 len)
>>> +{
>>> +       return (len < XGENE_DMA_MAX_BYTE_CNT) ?
>>> +               len : XGENE_DMA_16K_BUFFER_LEN_CODE;
>>> +}
>>> +
>>> +static u8 xgene_dma_encode_xor_flyby(u32 src_cnt)
>>> +{
>>> +       static u8 flyby_type[] = {
>>> +               FLYBY_2SRC_XOR, /* Dummy */
>>> +               FLYBY_2SRC_XOR, /* Dummy */
>>> +               FLYBY_2SRC_XOR,
>>> +               FLYBY_3SRC_XOR,
>>> +               FLYBY_4SRC_XOR,
>>> +               FLYBY_5SRC_XOR
>>> +       };
>>> +
>>> +       return flyby_type[src_cnt];
>>> +}
>>> +
>>> +static u32 xgene_dma_ring_desc_cnt(struct xgene_dma_ring *ring)
>>> +{
>>> +       u32 __iomem *cmd_base = ring->cmd_base;
>>> +       u32 ring_state = ioread32(&cmd_base[1]);
>>> +
>>> +       return XGENE_DMA_RING_DESC_CNT(ring_state);
>>> +}
>>> +
>>> +static void xgene_dma_set_src_buffer(void *ext8, size_t *len,
>>> +                                    dma_addr_t *paddr)
>>> +{
>>> +       size_t nbytes = (*len < XGENE_DMA_MAX_BYTE_CNT) ?
>>> +                       *len : XGENE_DMA_MAX_BYTE_CNT;
>>> +
>>> +       XGENE_DMA_DESC_BUFADDR_SET(ext8, *paddr);
>>> +       XGENE_DMA_DESC_BUFLEN_SET(ext8, xgene_dma_encode_len(nbytes));
>>> +       *len -= nbytes;
>>> +       *paddr += nbytes;
>>> +}
>>> +
>>> +static void xgene_dma_invalidate_buffer(void *ext8)
>>> +{
>>> +       XGENE_DMA_DESC_BUFLEN_SET(ext8, XGENE_DMA_INVALID_LEN_CODE);
>>> +}
>>> +
>>> +static void *xgene_dma_lookup_ext8(u64 *desc, int idx)
>>> +{
>>> +       return (idx % 2) ? (desc + idx - 1) : (desc + idx + 1);
>>> +}
>>> +
>>> +static void xgene_dma_init_desc(void *desc, u16 dst_ring_num)
>>> +{
>>> +       XGENE_DMA_DESC_C_SET(desc); /* Coherent IO */
>>> +       XGENE_DMA_DESC_IN_SET(desc);
>>> +       XGENE_DMA_DESC_H0ENQ_NUM_SET(desc, dst_ring_num);
>>> +       XGENE_DMA_DESC_RTYPE_SET(desc, XGENE_DMA_RING_OWNER_DMA);
>>> +}
>>> +
>>> +static void xgene_dma_prep_cpy_desc(struct xgene_dma_chan *chan,
>>> +                                   struct xgene_dma_desc_sw *desc_sw,
>>> +                                   dma_addr_t dst, dma_addr_t src,
>>> +                                   size_t len)
>>> +{
>>> +       void *desc1, *desc2;
>>> +       int i;
>>> +
>>> +       /* Get 1st descriptor */
>>> +       desc1 = &desc_sw->desc1;
>>> +       xgene_dma_init_desc(desc1, chan->tx_ring.dst_ring_num);
>>> +
>>> +       /* Set destination address */
>>> +       XGENE_DMA_DESC_DR_SET(desc1);
>>> +       XGENE_DMA_DESC_DST_ADDR_SET(desc1, dst);
>>> +
>>> +       /* Set 1st source address */
>>> +       xgene_dma_set_src_buffer(desc1 + 8, &len, &src);
>>> +
>>> +       if (len <= 0) {
>>> +               desc2 = NULL;
>>> +               goto skip_additional_src;
>>> +       }
>>> +
>>> +       /*
>>> +        * We need to split this source buffer,
>>> +        * and need to use 2nd descriptor
>>> +        */
>>> +       desc2 = &desc_sw->desc2;
>>> +       XGENE_DMA_DESC_NV_SET(desc1);
>>> +
>>> +       /* Set 2nd to 5th source address */
>>> +       for (i = 0; i < 4 && len; i++)
>>> +               xgene_dma_set_src_buffer(xgene_dma_lookup_ext8(desc2, i),
>>> +                                        &len, &src);
>>> +
>>> +       /* Invalidate unused source address field */
>>> +       for (; i < 4; i++)
>>> +               xgene_dma_invalidate_buffer(xgene_dma_lookup_ext8(desc2, i));
>>> +
>>> +       /* Updated flag that we have prepared 64B descriptor */
>>> +       desc_sw->flags |= XGENE_DMA_FLAG_64B_DESC;
>>> +
>>> +skip_additional_src:
>>> +       /* Hardware stores descriptor in little endian format */
>>> +       xgene_dma_cpu_to_le64(desc1, 4);
>>> +       if (desc2)
>>> +               xgene_dma_cpu_to_le64(desc2, 4);
>>> +}
>>> +
>>> +static void xgene_dma_prep_xor_desc(struct xgene_dma_chan *chan,
>>> +                                   struct xgene_dma_desc_sw *desc_sw,
>>> +                                   dma_addr_t *dst, dma_addr_t *src,
>>> +                                   u32 src_cnt, size_t *nbytes,
>>> +                                   const u8 *scf)
>>> +{
>>> +       void *desc1, *desc2;
>>> +       size_t len = *nbytes;
>>> +       int i;
>>> +
>>> +       desc1 = &desc_sw->desc1;
>>> +       desc2 = &desc_sw->desc2;
>>> +
>>> +       /* Initialize DMA descriptor */
>>> +       xgene_dma_init_desc(desc1, chan->tx_ring.dst_ring_num);
>>> +
>>> +       /* Set destination address */
>>> +       XGENE_DMA_DESC_DR_SET(desc1);
>>> +       XGENE_DMA_DESC_DST_ADDR_SET(desc1, *dst);
>>> +
>>> +       /* We have multiple source addresses, so need to set NV bit*/
>>> +       XGENE_DMA_DESC_NV_SET(desc1);
>>> +
>>> +       /* Set flyby opcode */
>>> +       XGENE_DMA_DESC_FLYBY_SET(desc1, xgene_dma_encode_xor_flyby(src_cnt));
>>> +
>>> +       /* Set 1st to 5th source addresses */
>>> +       for (i = 0; i < src_cnt; i++) {
>>> +               len = *nbytes;
>>> +               xgene_dma_set_src_buffer((i == 0) ? (desc1 + 8) :
>>> +                                        xgene_dma_lookup_ext8(desc2, i - 1),
>>> +                                        &len, &src[i]);
>>> +               XGENE_DMA_DESC_MULTI_SET(desc1, scf[i], i);
>>> +       }
>>> +
>>> +       /* Hardware stores descriptor in little endian format */
>>> +       xgene_dma_cpu_to_le64(desc1, 4);
>>> +       xgene_dma_cpu_to_le64(desc2, 4);
>>> +
>>> +       /* Update meta data */
>>> +       *nbytes = len;
>>> +       *dst += XGENE_DMA_MAX_BYTE_CNT;
>>> +
>>> +       /* We need always 64B descriptor to perform xor or pq operations */
>>> +       desc_sw->flags |= XGENE_DMA_FLAG_64B_DESC;
>>> +}
>>> +
>>> +static dma_cookie_t xgene_dma_tx_submit(struct dma_async_tx_descriptor *tx)
>>> +{
>>> +       struct xgene_dma_desc_sw *desc;
>>> +       struct xgene_dma_chan *chan;
>>> +       dma_cookie_t cookie;
>>> +
>>> +       if (unlikely(!tx))
>>> +               return -EINVAL;
>>> +
>>> +       chan = to_dma_chan(tx->chan);
>>> +       desc = to_dma_desc_sw(tx);
>>> +
>>> +       spin_lock_bh(&chan->lock);
>>> +
>>> +       cookie = dma_cookie_assign(tx);
>>> +
>>> +       /* Add this transaction list onto the tail of the pending queue */
>>> +       list_splice_tail_init(&desc->tx_list, &chan->ld_pending);
>>> +
>>> +       spin_unlock_bh(&chan->lock);
>>> +
>>> +       return cookie;
>>> +}
>>> +
>>> +static void xgene_dma_clean_descriptor(struct xgene_dma_chan *chan,
>>> +                                      struct xgene_dma_desc_sw *desc)
>>> +{
>>> +       list_del(&desc->node);
>>> +       chan_dbg(chan, "LD %p free\n", desc);
>>> +       dma_pool_free(chan->desc_pool, desc, desc->tx.phys);
>>> +}
>>> +
>>> +static struct xgene_dma_desc_sw *xgene_dma_alloc_descriptor(
>>> +                                struct xgene_dma_chan *chan)
>>> +{
>>> +       struct xgene_dma_desc_sw *desc;
>>> +       dma_addr_t phys;
>>> +
>>> +       desc = dma_pool_alloc(chan->desc_pool, GFP_NOWAIT, &phys);
>>> +       if (!desc) {
>>> +               chan_err(chan, "Failed to allocate LDs\n");
>>> +               return NULL;
>>> +       }
>>> +
>>> +       memset(desc, 0, sizeof(*desc));
>>> +
>>> +       INIT_LIST_HEAD(&desc->tx_list);
>>> +       desc->tx.phys = phys;
>>> +       desc->tx.tx_submit = xgene_dma_tx_submit;
>>> +       dma_async_tx_descriptor_init(&desc->tx, &chan->dma_chan);
>>> +
>>> +       chan_dbg(chan, "LD %p allocated\n", desc);
>>> +
>>> +       return desc;
>>> +}
>>> +
>>> +/**
>>> + * xgene_dma_clean_completed_descriptor - free all descriptors which
>>> + * has been completed and acked
>>> + * @chan: X-Gene DMA channel
>>> + *
>>> + * This function is used on all completed and acked descriptors.
>>> + */
>>> +static void xgene_dma_clean_completed_descriptor(struct xgene_dma_chan *chan)
>>> +{
>>> +       struct xgene_dma_desc_sw *desc, *_desc;
>>> +
>>> +       /* Run the callback for each descriptor, in order */
>>> +       list_for_each_entry_safe(desc, _desc, &chan->ld_completed, node) {
>>> +               if (async_tx_test_ack(&desc->tx))
>>> +                       xgene_dma_clean_descriptor(chan, desc);
>>> +       }
>>> +}
>>> +
>>> +/**
>>> + * xgene_dma_run_tx_complete_actions - cleanup a single link descriptor
>>> + * @chan: X-Gene DMA channel
>>> + * @desc: descriptor to cleanup and free
>>> + *
>>> + * This function is used on a descriptor which has been executed by the DMA
>>> + * controller. It will run any callbacks, submit any dependencies.
>>> + */
>>> +static void xgene_dma_run_tx_complete_actions(struct xgene_dma_chan *chan,
>>> +                                             struct xgene_dma_desc_sw *desc)
>>> +{
>>> +       struct dma_async_tx_descriptor *tx = &desc->tx;
>>> +
>>> +       /*
>>> +        * If this is not the last transaction in the group,
>>> +        * then no need to complete cookie and run any callback as
>>> +        * this is not the tx_descriptor which had been sent to caller
>>> +        * of this DMA request
>>> +        */
>>> +
>>> +       if (tx->cookie == 0)
>>> +               return;
>>> +
>>> +       dma_cookie_complete(tx);
>>> +
>>> +       /* Run the link descriptor callback function */
>>> +       if (tx->callback)
>>> +               tx->callback(tx->callback_param);
>>> +
>>> +       dma_descriptor_unmap(tx);
>>> +
>>> +       /* Run any dependencies */
>>> +       dma_run_dependencies(tx);
>>> +}
>>> +
>>> +/**
>>> + * xgene_dma_clean_running_descriptor - move the completed descriptor from
>>> + * ld_running to ld_completed
>>> + * @chan: X-Gene DMA channel
>>> + * @desc: the descriptor which is completed
>>> + *
>>> + * Free the descriptor directly if acked by async_tx api,
>>> + * else move it to queue ld_completed.
>>> + */
>>> +static void xgene_dma_clean_running_descriptor(struct xgene_dma_chan *chan,
>>> +                                              struct xgene_dma_desc_sw *desc)
>>> +{
>>> +       /* Remove from the list of running transactions */
>>> +       list_del(&desc->node);
>>> +
>>> +       /*
>>> +        * the client is allowed to attach dependent operations
>>> +        * until 'ack' is set
>>> +        */
>>> +       if (!async_tx_test_ack(&desc->tx)) {
>>> +               /*
>>> +                * Move this descriptor to the list of descriptors which is
>>> +                * completed, but still awaiting the 'ack' bit to be set.
>>> +                */
>>> +               list_add_tail(&desc->node, &chan->ld_completed);
>>> +               return;
>>> +       }
>>> +
>>> +       chan_dbg(chan, "LD %p free\n", desc);
>>> +       dma_pool_free(chan->desc_pool, desc, desc->tx.phys);
>>> +}
>>> +
>>> +static int xgene_chan_xfer_request(struct xgene_dma_ring *ring,
>>> +                                  struct xgene_dma_desc_sw *desc_sw)
>>> +{
>>> +       struct xgene_dma_desc_hw *desc_hw;
>>> +
>>> +       /* Check if can push more descriptor to hw for execution */
>>> +       if (xgene_dma_ring_desc_cnt(ring) > (ring->slots - 2))
>>> +               return -EBUSY;
>>> +
>>> +       /* Get hw descriptor from DMA tx ring */
>>> +       desc_hw = &ring->desc_hw[ring->head];
>>> +
>>> +       /*
>>> +        * Increment the head count to point next
>>> +        * descriptor for next time
>>> +        */
>>> +       if (++ring->head == ring->slots)
>>> +               ring->head = 0;
>>> +
>>> +       /* Copy prepared sw descriptor data to hw descriptor */
>>> +       memcpy(desc_hw, &desc_sw->desc1, sizeof(*desc_hw));
>>> +
>>> +       /*
>>> +        * Check if we have prepared 64B descriptor,
>>> +        * in this case we need one more hw descriptor
>>> +        */
>>> +       if (desc_sw->flags & XGENE_DMA_FLAG_64B_DESC) {
>>> +               desc_hw = &ring->desc_hw[ring->head];
>>> +
>>> +               if (++ring->head == ring->slots)
>>> +                       ring->head = 0;
>>> +
>>> +               memcpy(desc_hw, &desc_sw->desc2, sizeof(*desc_hw));
>>> +       }
>>> +
>>> +       /* Notify the hw that we have descriptor ready for execution */
>>> +       iowrite32((desc_sw->flags & XGENE_DMA_FLAG_64B_DESC) ?
>>> +                 2 : 1, ring->cmd);
>>> +
>>> +       return 0;
>>> +}
>>> +
>>> +/**
>>> + * xgene_chan_xfer_ld_pending - push any pending transactions to hw
>>> + * @chan : X-Gene DMA channel
>>> + *
>>> + * LOCKING: must hold chan->desc_lock
>>> + */
>>> +static void xgene_chan_xfer_ld_pending(struct xgene_dma_chan *chan)
>>> +{
>>> +       struct xgene_dma_desc_sw *desc_sw, *_desc_sw;
>>> +       int ret;
>>> +
>>> +       /*
>>> +        * If the list of pending descriptors is empty, then we
>>> +        * don't need to do any work at all
>>> +        */
>>> +       if (list_empty(&chan->ld_pending)) {
>>> +               chan_dbg(chan, "No pending LDs\n");
>>> +               return;
>>> +       }
>>> +
>>> +       /*
>>> +        * Move elements from the queue of pending transactions onto the list
>>> +        * of running transactions and push it to hw for further executions
>>> +        */
>>> +       list_for_each_entry_safe(desc_sw, _desc_sw, &chan->ld_pending, node) {
>>> +               /*
>>> +                * Check if have pushed max number of transactions to hw
>>> +                * as capable, so let's stop here and will push remaining
>>> +                * elements from pening ld queue after completing some
>>> +                * descriptors that we have already pushed
>>> +                */
>>> +               if (chan->pending >= chan->max_outstanding)
>>> +                       return;
>>> +
>>> +               ret = xgene_chan_xfer_request(&chan->tx_ring, desc_sw);
>>> +               if (ret)
>>> +                       return;
>>> +
>>> +               /*
>>> +                * Delete this element from ld pending queue and append it to
>>> +                * ld running queue
>>> +                */
>>> +               list_move_tail(&desc_sw->node, &chan->ld_running);
>>> +
>>> +               /* Increment the pending transaction count */
>>> +               chan->pending++;
>>> +       }
>>> +}
>>> +
>>> +/**
>>> + * xgene_dma_cleanup_descriptors - cleanup link descriptors which are completed
>>> + * and move them to ld_completed to free until flag 'ack' is set
>>> + * @chan: X-Gene DMA channel
>>> + *
>>> + * This function is used on descriptors which have been executed by the DMA
>>> + * controller. It will run any callbacks, submit any dependencies, then
>>> + * free these descriptors if flag 'ack' is set.
>>> + */
>>> +static void xgene_dma_cleanup_descriptors(struct xgene_dma_chan *chan)
>>> +{
>>> +       struct xgene_dma_ring *ring = &chan->rx_ring;
>>> +       struct xgene_dma_desc_sw *desc_sw, *_desc_sw;
>>> +       struct xgene_dma_desc_hw *desc_hw;
>>> +       u8 status;
>>> +
>>> +       /* Clean already completed and acked descriptors */
>>> +       xgene_dma_clean_completed_descriptor(chan);
>>> +
>>> +       /* Run the callback for each descriptor, in order */
>>> +       list_for_each_entry_safe(desc_sw, _desc_sw, &chan->ld_running, node) {
>>> +               /* Get subsequent hw descriptor from DMA rx ring */
>>> +               desc_hw = &ring->desc_hw[ring->head];
>>> +
>>> +               /* Check if this descriptor has been completed */
>>> +               if (unlikely(XGENE_DMA_DESC_IS_EMPTY(desc_hw)))
>>> +                       break;
>>> +
>>> +               if (++ring->head == ring->slots)
>>> +                       ring->head = 0;
>>> +
>>> +               /* Check if we have any error with DMA transactions */
>>> +               status = XGENE_DMA_DESC_STATUS(
>>> +                               XGENE_DMA_DESC_ELERR_RD(le64_to_cpu(
>>> +                                                       desc_hw->m0)),
>>> +                               XGENE_DMA_DESC_LERR_RD(le64_to_cpu(
>>> +                                                      desc_hw->m0)));
>>> +               if (status) {
>>> +                       /* Print the DMA error type */
>>> +                       chan_err(chan, "%s\n", xgene_dma_desc_err[status]);
>>> +
>>> +                       /*
>>> +                        * We have DMA transactions error here. Dump DMA Tx
>>> +                        * and Rx descriptors for this request */
>>> +                       XGENE_DMA_DESC_DUMP(&desc_sw->desc1,
>>> +                                           "X-Gene DMA TX DESC1: ");
>>> +
>>> +                       if (desc_sw->flags & XGENE_DMA_FLAG_64B_DESC)
>>> +                               XGENE_DMA_DESC_DUMP(&desc_sw->desc2,
>>> +                                                   "X-Gene DMA TX DESC2: ");
>>> +
>>> +                       XGENE_DMA_DESC_DUMP(desc_hw,
>>> +                                           "X-Gene DMA RX ERR DESC: ");
>>> +               }
>>> +
>>> +               /* Notify the hw about this completed descriptor */
>>> +               iowrite32(-1, ring->cmd);
>>> +
>>> +               /* Mark this hw descriptor as processed */
>>> +               XGENE_DMA_DESC_SET_EMPTY(desc_hw);
>>> +
>>> +               xgene_dma_run_tx_complete_actions(chan, desc_sw);
>>> +
>>> +               xgene_dma_clean_running_descriptor(chan, desc_sw);
>>> +
>>> +               /*
>>> +                * Decrement the pending transaction count
>>> +                * as we have processed one
>>> +                */
>>> +               chan->pending--;
>>> +       }
>>> +
>>> +       /*
>>> +        * Start any pending transactions automatically
>>> +        * In the ideal case, we keep the DMA controller busy while we go
>>> +        * ahead and free the descriptors below.
>>> +        */
>>> +       xgene_chan_xfer_ld_pending(chan);
>>> +}
>>> +
>>> +static int xgene_dma_alloc_chan_resources(struct dma_chan *dchan)
>>> +{
>>> +       struct xgene_dma_chan *chan = to_dma_chan(dchan);
>>> +
>>> +       /* Has this channel already been allocated? */
>>> +       if (chan->desc_pool)
>>> +               return 1;
>>> +
>>> +       chan->desc_pool = dma_pool_create(chan->name, chan->dev,
>>> +                                         sizeof(struct xgene_dma_desc_sw),
>>> +                                         0, 0);
>>> +       if (!chan->desc_pool) {
>>> +               chan_err(chan, "Failed to allocate descriptor pool\n");
>>> +               return -ENOMEM;
>>> +       }
>>> +
>>> +       chan_dbg(chan, "Allocate descripto pool\n");
>>> +
>>> +       return 1;
>>> +}
>>> +
>>> +/**
>>> + * xgene_dma_free_desc_list - Free all descriptors in a queue
>>> + * @chan: X-Gene DMA channel
>>> + * @list: the list to free
>>> + *
>>> + * LOCKING: must hold chan->desc_lock
>>> + */
>>> +static void xgene_dma_free_desc_list(struct xgene_dma_chan *chan,
>>> +                                    struct list_head *list)
>>> +{
>>> +       struct xgene_dma_desc_sw *desc, *_desc;
>>> +
>>> +       list_for_each_entry_safe(desc, _desc, list, node)
>>> +               xgene_dma_clean_descriptor(chan, desc);
>>> +}
>>> +
>>> +static void xgene_dma_free_tx_desc_list(struct xgene_dma_chan *chan,
>>> +                                       struct list_head *list)
>>> +{
>>> +       struct xgene_dma_desc_sw *desc, *_desc;
>>> +
>>> +       list_for_each_entry_safe(desc, _desc, list, node)
>>> +               xgene_dma_clean_descriptor(chan, desc);
>>> +}
>>> +
>>> +static void xgene_dma_free_chan_resources(struct dma_chan *dchan)
>>> +{
>>> +       struct xgene_dma_chan *chan = to_dma_chan(dchan);
>>> +
>>> +       chan_dbg(chan, "Free all resources\n");
>>> +
>>> +       if (!chan->desc_pool)
>>> +               return;
>>> +
>>> +       spin_lock_bh(&chan->lock);
>>> +
>>> +       /* Process all running descriptor */
>>> +       xgene_dma_cleanup_descriptors(chan);
>>> +
>>> +       /* Clean all link descriptor queues */
>>> +       xgene_dma_free_desc_list(chan, &chan->ld_pending);
>>> +       xgene_dma_free_desc_list(chan, &chan->ld_running);
>>> +       xgene_dma_free_desc_list(chan, &chan->ld_completed);
>>> +
>>> +       spin_unlock_bh(&chan->lock);
>>> +
>>> +       /* Delete this channel DMA pool */
>>> +       dma_pool_destroy(chan->desc_pool);
>>> +       chan->desc_pool = NULL;
>>> +}
>>> +
>>> +static struct dma_async_tx_descriptor *xgene_dma_prep_memcpy(
>>> +       struct dma_chan *dchan, dma_addr_t dst, dma_addr_t src,
>>> +       size_t len, unsigned long flags)
>>> +{
>>> +       struct xgene_dma_desc_sw *first = NULL, *new;
>>> +       struct xgene_dma_chan *chan;
>>> +       size_t copy;
>>> +
>>> +       if (unlikely(!dchan || !len))
>>> +               return NULL;
>>> +
>>> +       chan = to_dma_chan(dchan);
>>> +
>>> +       do {
>>> +               /* Allocate the link descriptor from DMA pool */
>>> +               new = xgene_dma_alloc_descriptor(chan);
>>> +               if (!new)
>>> +                       goto fail;
>>> +
>>> +               /* Create the largest transaction possible */
>>> +               copy = min_t(size_t, len, XGENE_DMA_MAX_64B_DESC_BYTE_CNT);
>>> +
>>> +               /* Prepare DMA descriptor */
>>> +               xgene_dma_prep_cpy_desc(chan, new, dst, src, copy);
>>> +
>>> +               if (!first)
>>> +                       first = new;
>>> +
>>> +               new->tx.cookie = 0;
>>> +               async_tx_ack(&new->tx);
>>> +
>>> +               /* Update metadata */
>>> +               len -= copy;
>>> +               dst += copy;
>>> +               src += copy;
>>> +
>>> +               /* Insert the link descriptor to the LD ring */
>>> +               list_add_tail(&new->node, &first->tx_list);
>>> +       } while (len);
>>> +
>>> +       new->tx.flags = flags; /* client is in control of this ack */
>>> +       new->tx.cookie = -EBUSY;
>>> +       list_splice(&first->tx_list, &new->tx_list);
>>> +
>>> +       return &new->tx;
>>> +
>>> +fail:
>>> +       if (!first)
>>> +               return NULL;
>>> +
>>> +       xgene_dma_free_tx_desc_list(chan, &first->tx_list);
>>> +       return NULL;
>>> +}
>>> +
>>> +static struct dma_async_tx_descriptor *xgene_dma_prep_sg(
>>> +       struct dma_chan *dchan, struct scatterlist *dst_sg,
>>> +       u32 dst_nents, struct scatterlist *src_sg,
>>> +       u32 src_nents, unsigned long flags)
>>> +{
>>> +       struct xgene_dma_desc_sw *first = NULL, *new = NULL;
>>> +       struct xgene_dma_chan *chan;
>>> +       size_t dst_avail, src_avail;
>>> +       dma_addr_t dst, src;
>>> +       size_t len;
>>> +
>>> +       if (unlikely(!dchan))
>>> +               return NULL;
>>> +
>>> +       if (unlikely(!dst_nents || !src_nents))
>>> +               return NULL;
>>> +
>>> +       if (unlikely(!dst_sg || !src_sg))
>>> +               return NULL;
>>> +
>>> +       chan = to_dma_chan(dchan);
>>> +
>>> +       /* Get prepared for the loop */
>>> +       dst_avail = sg_dma_len(dst_sg);
>>> +       src_avail = sg_dma_len(src_sg);
>>> +       dst_nents--;
>>> +       src_nents--;
>>> +
>>> +       /* Run until we are out of scatterlist entries */
>>> +       while (true) {
>>> +               /* Create the largest transaction possible */
>>> +               len = min_t(size_t, src_avail, dst_avail);
>>> +               len = min_t(size_t, len, XGENE_DMA_MAX_64B_DESC_BYTE_CNT);
>>> +               if (len == 0)
>>> +                       goto fetch;
>>> +
>>> +               dst = sg_dma_address(dst_sg) + sg_dma_len(dst_sg) - dst_avail;
>>> +               src = sg_dma_address(src_sg) + sg_dma_len(src_sg) - src_avail;
>>> +
>>> +               /* Allocate the link descriptor from DMA pool */
>>> +               new = xgene_dma_alloc_descriptor(chan);
>>> +               if (!new)
>>> +                       goto fail;
>>> +
>>> +               /* Prepare DMA descriptor */
>>> +               xgene_dma_prep_cpy_desc(chan, new, dst, src, len);
>>> +
>>> +               if (!first)
>>> +                       first = new;
>>> +
>>> +               new->tx.cookie = 0;
>>> +               async_tx_ack(&new->tx);
>>> +
>>> +               /* update metadata */
>>> +               dst_avail -= len;
>>> +               src_avail -= len;
>>> +
>>> +               /* Insert the link descriptor to the LD ring */
>>> +               list_add_tail(&new->node, &first->tx_list);
>>> +
>>> +fetch:
>>> +               /* fetch the next dst scatterlist entry */
>>> +               if (dst_avail == 0) {
>>> +                       /* no more entries: we're done */
>>> +                       if (dst_nents == 0)
>>> +                               break;
>>> +
>>> +                       /* fetch the next entry: if there are no more: done */
>>> +                       dst_sg = sg_next(dst_sg);
>>> +                       if (!dst_sg)
>>> +                               break;
>>> +
>>> +                       dst_nents--;
>>> +                       dst_avail = sg_dma_len(dst_sg);
>>> +               }
>>> +
>>> +               /* fetch the next src scatterlist entry */
>>> +               if (src_avail == 0) {
>>> +                       /* no more entries: we're done */
>>> +                       if (src_nents == 0)
>>> +                               break;
>>> +
>>> +                       /* fetch the next entry: if there are no more: done */
>>> +                       src_sg = sg_next(src_sg);
>>> +                       if (!src_sg)
>>> +                               break;
>>> +
>>> +                       src_nents--;
>>> +                       src_avail = sg_dma_len(src_sg);
>>> +               }
>>> +       }
>>> +
>>> +       if (!new)
>>> +               return NULL;
>>> +
>>> +       new->tx.flags = flags; /* client is in control of this ack */
>>> +       new->tx.cookie = -EBUSY;
>>> +       list_splice(&first->tx_list, &new->tx_list);
>>> +
>>> +       return &new->tx;
>>> +fail:
>>> +       if (!first)
>>> +               return NULL;
>>> +
>>> +       xgene_dma_free_tx_desc_list(chan, &first->tx_list);
>>> +       return NULL;
>>> +}
>>> +
>>> +static struct dma_async_tx_descriptor *xgene_dma_prep_xor(
>>> +       struct dma_chan *dchan, dma_addr_t dst, dma_addr_t *src,
>>> +       u32 src_cnt, size_t len, unsigned long flags)
>>> +{
>>> +       struct xgene_dma_desc_sw *first = NULL, *new;
>>> +       struct xgene_dma_chan *chan;
>>> +       static u8 multi[XGENE_DMA_MAX_XOR_SRC] = {
>>> +                               0x01, 0x01, 0x01, 0x01, 0x01};
>>> +
>>> +       if (unlikely(!dchan || !len))
>>> +               return NULL;
>>> +
>>> +       chan = to_dma_chan(dchan);
>>> +
>>> +       do {
>>> +               /* Allocate the link descriptor from DMA pool */
>>> +               new = xgene_dma_alloc_descriptor(chan);
>>> +               if (!new)
>>> +                       goto fail;
>>> +
>>> +               /* Prepare xor DMA descriptor */
>>> +               xgene_dma_prep_xor_desc(chan, new, &dst, src,
>>> +                                       src_cnt, &len, multi);
>>> +
>>> +               if (!first)
>>> +                       first = new;
>>> +
>>> +               new->tx.cookie = 0;
>>> +               async_tx_ack(&new->tx);
>>> +
>>> +               /* Insert the link descriptor to the LD ring */
>>> +               list_add_tail(&new->node, &first->tx_list);
>>> +       } while (len);
>>> +
>>> +       new->tx.flags = flags; /* client is in control of this ack */
>>> +       new->tx.cookie = -EBUSY;
>>> +       list_splice(&first->tx_list, &new->tx_list);
>>> +
>>> +       return &new->tx;
>>> +
>>> +fail:
>>> +       if (!first)
>>> +               return NULL;
>>> +
>>> +       xgene_dma_free_tx_desc_list(chan, &first->tx_list);
>>> +       return NULL;
>>> +}
>>> +
>>> +static struct dma_async_tx_descriptor *xgene_dma_prep_pq(
>>> +       struct dma_chan *dchan, dma_addr_t *dst, dma_addr_t *src,
>>> +       u32 src_cnt, const u8 *scf, size_t len, unsigned long flags)
>>> +{
>>> +       struct xgene_dma_desc_sw *first = NULL, *new;
>>> +       struct xgene_dma_chan *chan;
>>> +       size_t _len = len;
>>> +       dma_addr_t _src[XGENE_DMA_MAX_XOR_SRC];
>>> +       static u8 multi[XGENE_DMA_MAX_XOR_SRC] = {0x01, 0x01, 0x01, 0x01, 0x01};
>>> +
>>> +       if (unlikely(!dchan || !len))
>>> +               return NULL;
>>> +
>>> +       chan = to_dma_chan(dchan);
>>> +
>>> +       /*
>>> +        * Save source addresses on local variable, may be we have to
>>> +        * prepare two descriptor to generate P and Q if both enabled
>>> +        * in the flags by client
>>> +        */
>>> +       memcpy(_src, src, sizeof(*src) * src_cnt);
>>> +
>>> +       if (flags & DMA_PREP_PQ_DISABLE_P)
>>> +               len = 0;
>>> +
>>> +       if (flags & DMA_PREP_PQ_DISABLE_Q)
>>> +               _len = 0;
>>> +
>>> +       do {
>>> +               /* Allocate the link descriptor from DMA pool */
>>> +               new = xgene_dma_alloc_descriptor(chan);
>>> +               if (!new)
>>> +                       goto fail;
>>> +
>>> +               if (!first)
>>> +                       first = new;
>>> +
>>> +               new->tx.cookie = 0;
>>> +               async_tx_ack(&new->tx);
>>> +
>>> +               /* Insert the link descriptor to the LD ring */
>>> +               list_add_tail(&new->node, &first->tx_list);
>>> +
>>> +               /*
>>> +                * Prepare DMA descriptor to generate P,
>>> +                * if DMA_PREP_PQ_DISABLE_P flag is not set
>>> +                */
>>> +               if (len) {
>>> +                       xgene_dma_prep_xor_desc(chan, new, &dst[0], src,
>>> +                                               src_cnt, &len, multi);
>>> +                       continue;
>>> +               }
>>> +
>>> +               /*
>>> +                * Prepare DMA descriptor to generate Q,
>>> +                * if DMA_PREP_PQ_DISABLE_Q flag is not set
>>> +                */
>>> +               if (_len) {
>>> +                       xgene_dma_prep_xor_desc(chan, new, &dst[1], _src,
>>> +                                               src_cnt, &_len, scf);
>>> +               }
>>> +       } while (len || _len);
>>> +
>>> +       new->tx.flags = flags; /* client is in control of this ack */
>>> +       new->tx.cookie = -EBUSY;
>>> +       list_splice(&first->tx_list, &new->tx_list);
>>> +
>>> +       return &new->tx;
>>> +
>>> +fail:
>>> +       if (!first)
>>> +               return NULL;
>>> +
>>> +       xgene_dma_free_tx_desc_list(chan, &first->tx_list);
>>> +       return NULL;
>>> +}
>>> +
>>> +static void xgene_dma_issue_pending(struct dma_chan *dchan)
>>> +{
>>> +       struct xgene_dma_chan *chan = to_dma_chan(dchan);
>>> +
>>> +       spin_lock_bh(&chan->lock);
>>> +       xgene_chan_xfer_ld_pending(chan);
>>> +       spin_unlock_bh(&chan->lock);
>>> +}
>>> +
>>> +static enum dma_status xgene_dma_tx_status(struct dma_chan *dchan,
>>> +                                          dma_cookie_t cookie,
>>> +                                          struct dma_tx_state *txstate)
>>> +{
>>> +       return dma_cookie_status(dchan, cookie, txstate);
>>> +}
>>> +
>>> +static void xgene_dma_tasklet_cb(unsigned long data)
>>> +{
>>> +       struct xgene_dma_chan *chan = (struct xgene_dma_chan *)data;
>>> +
>>> +       spin_lock_bh(&chan->lock);
>>> +
>>> +       /* Run all cleanup for descriptors which have been completed */
>>> +       xgene_dma_cleanup_descriptors(chan);
>>> +
>>> +       /* Re-enable DMA channel IRQ */
>>> +       enable_irq(chan->rx_irq);
>>> +
>>> +       spin_unlock_bh(&chan->lock);
>>> +}
>>> +
>>> +static irqreturn_t xgene_dma_chan_ring_isr(int irq, void *id)
>>> +{
>>> +       struct xgene_dma_chan *chan = (struct xgene_dma_chan *)id;
>>> +
>>> +       BUG_ON(!chan);
>>> +
>>> +       /*
>>> +        * Disable DMA channel IRQ until we process completed
>>> +        * descriptors
>>> +        */
>>> +       disable_irq_nosync(chan->rx_irq);
>>> +
>>> +       /*
>>> +        * Schedule the tasklet to handle all cleanup of the current
>>> +        * transaction. It will start a new transaction if there is
>>> +        * one pending.
>>> +        */
>>> +       tasklet_schedule(&chan->tasklet);
>>> +
>>> +       return IRQ_HANDLED;
>>> +}
>>> +
>>> +static irqreturn_t xgene_dma_err_isr(int irq, void *id)
>>> +{
>>> +       struct xgene_dma *pdma = (struct xgene_dma *)id;
>>> +       unsigned long int_mask;
>>> +       u32 val, i;
>>> +
>>> +       val = ioread32(pdma->csr_dma + XGENE_DMA_INT);
>>> +
>>> +       /* Clear DMA interrupts */
>>> +       iowrite32(val, pdma->csr_dma + XGENE_DMA_INT);
>>> +
>>> +       /* Print DMA error info */
>>> +       int_mask = val >> XGENE_DMA_INT_MASK_SHIFT;
>>> +       for_each_set_bit(i, &int_mask, ARRAY_SIZE(xgene_dma_err))
>>> +               dev_err(pdma->dev,
>>> +                       "Interrupt status 0x%08X %s\n", val, xgene_dma_err[i]);
>>> +
>>> +       return IRQ_HANDLED;
>>> +}
>>> +
>>> +static void xgene_dma_wr_ring_state(struct xgene_dma_ring *ring)
>>> +{
>>> +       int i;
>>> +
>>> +       iowrite32(ring->num, ring->pdma->csr_ring + XGENE_DMA_RING_STATE);
>>> +
>>> +       for (i = 0; i < XGENE_DMA_RING_NUM_CONFIG; i++)
>>> +               iowrite32(ring->state[i], ring->pdma->csr_ring +
>>> +                         XGENE_DMA_RING_STATE_WR_BASE + (i * 4));
>>> +}
>>> +
>>> +static void xgene_dma_clr_ring_state(struct xgene_dma_ring *ring)
>>> +{
>>> +       memset(ring->state, 0, sizeof(u32) * XGENE_DMA_RING_NUM_CONFIG);
>>> +       xgene_dma_wr_ring_state(ring);
>>> +}
>>> +
>>> +static void xgene_dma_setup_ring(struct xgene_dma_ring *ring)
>>> +{
>>> +       void *ring_cfg = ring->state;
>>> +       u64 addr = ring->desc_paddr;
>>> +       void *desc;
>>> +       u32 i, val;
>>> +
>>> +       ring->slots = ring->size / XGENE_DMA_RING_WQ_DESC_SIZE;
>>> +
>>> +       /* Clear DMA ring state */
>>> +       xgene_dma_clr_ring_state(ring);
>>> +
>>> +       /* Set DMA ring type */
>>> +       XGENE_DMA_RING_TYPE_SET(ring_cfg, XGENE_DMA_RING_TYPE_REGULAR);
>>> +
>>> +       if (ring->owner == XGENE_DMA_RING_OWNER_DMA) {
>>> +               /* Set recombination buffer and timeout */
>>> +               XGENE_DMA_RING_RECOMBBUF_SET(ring_cfg);
>>> +               XGENE_DMA_RING_RECOMTIMEOUTL_SET(ring_cfg);
>>> +               XGENE_DMA_RING_RECOMTIMEOUTH_SET(ring_cfg);
>>> +       }
>>> +
>>> +       /* Initialize DMA ring state */
>>> +       XGENE_DMA_RING_SELTHRSH_SET(ring_cfg);
>>> +       XGENE_DMA_RING_ACCEPTLERR_SET(ring_cfg);
>>> +       XGENE_DMA_RING_COHERENT_SET(ring_cfg);
>>> +       XGENE_DMA_RING_ADDRL_SET(ring_cfg, addr);
>>> +       XGENE_DMA_RING_ADDRH_SET(ring_cfg, addr);
>>> +       XGENE_DMA_RING_SIZE_SET(ring_cfg, ring->cfgsize);
>>> +
>>> +       /* Write DMA ring configurations */
>>> +       xgene_dma_wr_ring_state(ring);
>>> +
>>> +       /* Set DMA ring id */
>>> +       iowrite32(XGENE_DMA_RING_ID_SETUP(ring->id),
>>> +                 ring->pdma->csr_ring + XGENE_DMA_RING_ID);
>>> +
>>> +       /* Set DMA ring buffer */
>>> +       iowrite32(XGENE_DMA_RING_ID_BUF_SETUP(ring->num),
>>> +                 ring->pdma->csr_ring + XGENE_DMA_RING_ID_BUF);
>>> +
>>> +       if (ring->owner != XGENE_DMA_RING_OWNER_CPU)
>>> +               return;
>>> +
>>> +       /* Set empty signature to DMA Rx ring descriptors */
>>> +       for (i = 0; i < ring->slots; i++) {
>>> +               desc = &ring->desc_hw[i];
>>> +               XGENE_DMA_DESC_SET_EMPTY(desc);
>>> +       }
>>> +
>>> +       /* Enable DMA Rx ring interrupt */
>>> +       val = ioread32(ring->pdma->csr_ring + XGENE_DMA_RING_NE_INT_MODE);
>>> +       XGENE_DMA_RING_NE_INT_MODE_SET(val, ring->buf_num);
>>> +       iowrite32(val, ring->pdma->csr_ring + XGENE_DMA_RING_NE_INT_MODE);
>>> +}
>>> +
>>> +static void xgene_dma_clear_ring(struct xgene_dma_ring *ring)
>>> +{
>>> +       u32 ring_id, val;
>>> +
>>> +       if (ring->owner == XGENE_DMA_RING_OWNER_CPU) {
>>> +               /* Disable DMA Rx ring interrupt */
>>> +               val = ioread32(ring->pdma->csr_ring +
>>> +                              XGENE_DMA_RING_NE_INT_MODE);
>>> +               XGENE_DMA_RING_NE_INT_MODE_RESET(val, ring->buf_num);
>>> +               iowrite32(val, ring->pdma->csr_ring +
>>> +                         XGENE_DMA_RING_NE_INT_MODE);
>>> +       }
>>> +
>>> +       /* Clear DMA ring state */
>>> +       ring_id = XGENE_DMA_RING_ID_SETUP(ring->id);
>>> +       iowrite32(ring_id, ring->pdma->csr_ring + XGENE_DMA_RING_ID);
>>> +
>>> +       iowrite32(0, ring->pdma->csr_ring + XGENE_DMA_RING_ID_BUF);
>>> +       xgene_dma_clr_ring_state(ring);
>>> +}
>>> +
>>> +static void xgene_dma_set_ring_cmd(struct xgene_dma_ring *ring)
>>> +{
>>> +       ring->cmd_base = ring->pdma->csr_ring_cmd +
>>> +                               XGENE_DMA_RING_CMD_BASE_OFFSET((ring->num -
>>> +                                                         XGENE_DMA_RING_NUM));
>>> +
>>> +       ring->cmd = ring->cmd_base + XGENE_DMA_RING_CMD_OFFSET;
>>> +}
>>> +
>>> +static int xgene_dma_get_ring_size(struct xgene_dma_chan *chan,
>>> +                                  enum xgene_dma_ring_cfgsize cfgsize)
>>> +{
>>> +       int size;
>>> +
>>> +       switch (cfgsize) {
>>> +       case XGENE_DMA_RING_CFG_SIZE_512B:
>>> +               size = 0x200;
>>> +               break;
>>> +       case XGENE_DMA_RING_CFG_SIZE_2KB:
>>> +               size = 0x800;
>>> +               break;
>>> +       case XGENE_DMA_RING_CFG_SIZE_16KB:
>>> +               size = 0x4000;
>>> +               break;
>>> +       case XGENE_DMA_RING_CFG_SIZE_64KB:
>>> +               size = 0x10000;
>>> +               break;
>>> +       case XGENE_DMA_RING_CFG_SIZE_512KB:
>>> +               size = 0x80000;
>>> +               break;
>>> +       default:
>>> +               chan_err(chan, "Unsupported cfg ring size %d\n", cfgsize);
>>> +               return -EINVAL;
>>> +       }
>>> +
>>> +       return size;
>>> +}
>>> +
>>> +static void xgene_dma_delete_ring_one(struct xgene_dma_ring *ring)
>>> +{
>>> +       /* Clear DMA ring configurations */
>>> +       xgene_dma_clear_ring(ring);
>>> +
>>> +       /* De-allocate DMA ring descriptor */
>>> +       if (ring->desc_vaddr) {
>>> +               dma_free_coherent(ring->pdma->dev, ring->size,
>>> +                                 ring->desc_vaddr, ring->desc_paddr);
>>> +               ring->desc_vaddr = NULL;
>>> +       }
>>> +}
>>> +
>>> +static void xgene_dma_delete_chan_rings(struct xgene_dma_chan *chan)
>>> +{
>>> +       xgene_dma_delete_ring_one(&chan->rx_ring);
>>> +       xgene_dma_delete_ring_one(&chan->tx_ring);
>>> +}
>>> +
>>> +static int xgene_dma_create_ring_one(struct xgene_dma_chan *chan,
>>> +                                    struct xgene_dma_ring *ring,
>>> +                                    enum xgene_dma_ring_cfgsize cfgsize)
>>> +{
>>> +       /* Setup DMA ring descriptor variables */
>>> +       ring->pdma = chan->pdma;
>>> +       ring->cfgsize = cfgsize;
>>> +       ring->num = chan->pdma->ring_num++;
>>> +       ring->id = XGENE_DMA_RING_ID_GET(ring->owner, ring->buf_num);
>>> +
>>> +       ring->size = xgene_dma_get_ring_size(chan, cfgsize);
>>> +       if (ring->size <= 0)
>>> +               return ring->size;
>>> +
>>> +       /* Allocate memory for DMA ring descriptor */
>>> +       ring->desc_vaddr = dma_zalloc_coherent(chan->dev, ring->size,
>>> +                                              &ring->desc_paddr, GFP_KERNEL);
>>> +       if (!ring->desc_vaddr) {
>>> +               chan_err(chan, "Failed to allocate ring desc\n");
>>> +               return -ENOMEM;
>>> +       }
>>> +
>>> +       /* Configure and enable DMA ring */
>>> +       xgene_dma_set_ring_cmd(ring);
>>> +       xgene_dma_setup_ring(ring);
>>> +
>>> +       return 0;
>>> +}
>>> +
>>> +static int xgene_dma_create_chan_rings(struct xgene_dma_chan *chan)
>>> +{
>>> +       struct xgene_dma_ring *rx_ring = &chan->rx_ring;
>>> +       struct xgene_dma_ring *tx_ring = &chan->tx_ring;
>>> +       int ret;
>>> +
>>> +       /* Create DMA Rx ring descriptor */
>>> +       rx_ring->owner = XGENE_DMA_RING_OWNER_CPU;
>>> +       rx_ring->buf_num = XGENE_DMA_CPU_BUFNUM + chan->id;
>>> +
>>> +       ret = xgene_dma_create_ring_one(chan, rx_ring,
>>> +                                       XGENE_DMA_RING_CFG_SIZE_64KB);
>>> +       if (ret)
>>> +               return ret;
>>> +
>>> +       chan_dbg(chan, "Rx ring id 0x%X num %d desc 0x%p\n",
>>> +                rx_ring->id, rx_ring->num, rx_ring->desc_vaddr);
>>> +
>>> +       /* Create DMA Tx ring descriptor */
>>> +       tx_ring->owner = XGENE_DMA_RING_OWNER_DMA;
>>> +       tx_ring->buf_num = XGENE_DMA_BUFNUM + chan->id;
>>> +
>>> +       ret = xgene_dma_create_ring_one(chan, tx_ring,
>>> +                                       XGENE_DMA_RING_CFG_SIZE_64KB);
>>> +       if (ret) {
>>> +               xgene_dma_delete_ring_one(rx_ring);
>>> +               return ret;
>>> +       }
>>> +
>>> +       tx_ring->dst_ring_num = XGENE_DMA_RING_DST_ID(rx_ring->num);
>>> +
>>> +       chan_dbg(chan,
>>> +                "Tx ring id 0x%X num %d desc 0x%p\n",
>>> +                tx_ring->id, tx_ring->num, tx_ring->desc_vaddr);
>>> +
>>> +       /* Set the max outstanding request possible to this channel */
>>> +       chan->max_outstanding = rx_ring->slots;
>>> +
>>> +       return ret;
>>> +}
>>> +
>>> +static int xgene_dma_init_rings(struct xgene_dma *pdma)
>>> +{
>>> +       int ret, i, j;
>>> +
>>> +       for (i = 0; i < XGENE_DMA_MAX_CHANNEL; i++) {
>>> +               ret = xgene_dma_create_chan_rings(&pdma->chan[i]);
>>> +               if (ret) {
>>> +                       for (j = 0; j < i; j++)
>>> +                               xgene_dma_delete_chan_rings(&pdma->chan[j]);
>>> +                       return ret;
>>> +               }
>>> +       }
>>> +
>>> +       return ret;
>>> +}
>>> +
>>> +static void xgene_dma_enable(struct xgene_dma *pdma)
>>> +{
>>> +       u32 val;
>>> +
>>> +       /* Configure and enable DMA engine */
>>> +       val = ioread32(pdma->csr_dma + XGENE_DMA_GCR);
>>> +       XGENE_DMA_CH_SETUP(val);
>>> +       XGENE_DMA_ENABLE(val);
>>> +       iowrite32(val, pdma->csr_dma + XGENE_DMA_GCR);
>>> +}
>>> +
>>> +static void xgene_dma_disable(struct xgene_dma *pdma)
>>> +{
>>> +       u32 val;
>>> +
>>> +       val = ioread32(pdma->csr_dma + XGENE_DMA_GCR);
>>> +       XGENE_DMA_DISABLE(val);
>>> +       iowrite32(val, pdma->csr_dma + XGENE_DMA_GCR);
>>> +}
>>> +
>>> +static void xgene_dma_mask_interrupts(struct xgene_dma *pdma)
>>> +{
>>> +       /*
>>> +        * Mask DMA ring overflow, underflow and
>>> +        * AXI write/read error interrupts
>>> +        */
>>> +       iowrite32(XGENE_DMA_INT_ALL_MASK,
>>> +                 pdma->csr_dma + XGENE_DMA_RING_INT0_MASK);
>>> +       iowrite32(XGENE_DMA_INT_ALL_MASK,
>>> +                 pdma->csr_dma + XGENE_DMA_RING_INT1_MASK);
>>> +       iowrite32(XGENE_DMA_INT_ALL_MASK,
>>> +                 pdma->csr_dma + XGENE_DMA_RING_INT2_MASK);
>>> +       iowrite32(XGENE_DMA_INT_ALL_MASK,
>>> +                 pdma->csr_dma + XGENE_DMA_RING_INT3_MASK);
>>> +       iowrite32(XGENE_DMA_INT_ALL_MASK,
>>> +                 pdma->csr_dma + XGENE_DMA_RING_INT4_MASK);
>>> +
>>> +       /* Mask DMA error interrupts */
>>> +       iowrite32(XGENE_DMA_INT_ALL_MASK, pdma->csr_dma + XGENE_DMA_INT_MASK);
>>> +}
>>> +
>>> +static void xgene_dma_unmask_interrupts(struct xgene_dma *pdma)
>>> +{
>>> +       /*
>>> +        * Unmask DMA ring overflow, underflow and
>>> +        * AXI write/read error interrupts
>>> +        */
>>> +       iowrite32(XGENE_DMA_INT_ALL_UNMASK,
>>> +                 pdma->csr_dma + XGENE_DMA_RING_INT0_MASK);
>>> +       iowrite32(XGENE_DMA_INT_ALL_UNMASK,
>>> +                 pdma->csr_dma + XGENE_DMA_RING_INT1_MASK);
>>> +       iowrite32(XGENE_DMA_INT_ALL_UNMASK,
>>> +                 pdma->csr_dma + XGENE_DMA_RING_INT2_MASK);
>>> +       iowrite32(XGENE_DMA_INT_ALL_UNMASK,
>>> +                 pdma->csr_dma + XGENE_DMA_RING_INT3_MASK);
>>> +       iowrite32(XGENE_DMA_INT_ALL_UNMASK,
>>> +                 pdma->csr_dma + XGENE_DMA_RING_INT4_MASK);
>>> +
>>> +       /* Unmask DMA error interrupts */
>>> +       iowrite32(XGENE_DMA_INT_ALL_UNMASK,
>>> +                 pdma->csr_dma + XGENE_DMA_INT_MASK);
>>> +}
>>> +
>>> +static void xgene_dma_init_hw(struct xgene_dma *pdma)
>>> +{
>>> +       u32 val;
>>> +
>>> +       /* Associate DMA ring to corresponding ring HW */
>>> +       iowrite32(XGENE_DMA_ASSOC_RING_MNGR1,
>>> +                 pdma->csr_dma + XGENE_DMA_CFG_RING_WQ_ASSOC);
>>> +
>>> +       /* Configure RAID6 polynomial control setting */
>>> +       if (is_pq_enabled(pdma))
>>> +               iowrite32(XGENE_DMA_RAID6_MULTI_CTRL(0x1D),
>>> +                         pdma->csr_dma + XGENE_DMA_RAID6_CONT);
>>> +       else
>>> +               dev_info(pdma->dev, "PQ is disabled in HW\n");
>>> +
>>> +       xgene_dma_enable(pdma);
>>> +       xgene_dma_unmask_interrupts(pdma);
>>> +
>>> +       /* Get DMA id and version info */
>>> +       val = ioread32(pdma->csr_dma + XGENE_DMA_IPBRR);
>>> +
>>> +       /* DMA device info */
>>> +       dev_info(pdma->dev,
>>> +                "X-Gene DMA v%d.%02d.%02d driver registered %d channels",
>>> +                XGENE_DMA_REV_NO_RD(val), XGENE_DMA_BUS_ID_RD(val),
>>> +                XGENE_DMA_DEV_ID_RD(val), XGENE_DMA_MAX_CHANNEL);
>>> +}
>>> +
>>> +int xgene_dma_init_ring_mngr(struct xgene_dma *pdma)
>>> +{
>>> +       if (ioread32(pdma->csr_ring + XGENE_DMA_RING_CLKEN) &&
>>> +           (!ioread32(pdma->csr_ring + XGENE_DMA_RING_SRST)))
>>> +               return 0;
>>> +
>>> +       iowrite32(0x3, pdma->csr_ring + XGENE_DMA_RING_CLKEN);
>>> +       iowrite32(0x0, pdma->csr_ring + XGENE_DMA_RING_SRST);
>>> +
>>> +       /* Bring up memory */
>>> +       iowrite32(0x0, pdma->csr_ring + XGENE_DMA_RING_MEM_RAM_SHUTDOWN);
>>> +
>>> +       /* Force a barrier */
>>> +       ioread32(pdma->csr_ring + XGENE_DMA_RING_MEM_RAM_SHUTDOWN);
>>> +
>>> +       /* reset may take up to 1ms */
>>> +       usleep_range(1000, 1100);
>>> +
>>> +       if (ioread32(pdma->csr_ring + XGENE_DMA_RING_BLK_MEM_RDY)
>>> +               != XGENE_DMA_RING_BLK_MEM_RDY_VAL) {
>>> +               dev_err(pdma->dev,
>>> +                       "Failed to release ring mngr memory from shutdown\n");
>>> +               return -ENODEV;
>>> +       }
>>> +
>>> +       /* program threshold set 1 and all hysteresis */
>>> +       iowrite32(XGENE_DMA_RING_THRESLD0_SET1_VAL,
>>> +                 pdma->csr_ring + XGENE_DMA_RING_THRESLD0_SET1);
>>> +       iowrite32(XGENE_DMA_RING_THRESLD1_SET1_VAL,
>>> +                 pdma->csr_ring + XGENE_DMA_RING_THRESLD1_SET1);
>>> +       iowrite32(XGENE_DMA_RING_HYSTERESIS_VAL,
>>> +                 pdma->csr_ring + XGENE_DMA_RING_HYSTERESIS);
>>> +
>>> +       /* Enable QPcore and assign error queue */
>>> +       iowrite32(XGENE_DMA_RING_ENABLE,
>>> +                 pdma->csr_ring + XGENE_DMA_RING_CONFIG);
>>> +
>>> +       return 0;
>>> +}
>>> +
>>> +static int xgene_dma_init_mem(struct xgene_dma *pdma)
>>> +{
>>> +       int ret;
>>> +
>>> +       ret = xgene_dma_init_ring_mngr(pdma);
>>> +       if (ret)
>>> +               return ret;
>>> +
>>> +       /* Bring up memory */
>>> +       iowrite32(0x0, pdma->csr_dma + XGENE_DMA_MEM_RAM_SHUTDOWN);
>>> +
>>> +       /* Force a barrier */
>>> +       ioread32(pdma->csr_dma + XGENE_DMA_MEM_RAM_SHUTDOWN);
>>> +
>>> +       /* reset may take up to 1ms */
>>> +       usleep_range(1000, 1100);
>>> +
>>> +       if (ioread32(pdma->csr_dma + XGENE_DMA_BLK_MEM_RDY)
>>> +               != XGENE_DMA_BLK_MEM_RDY_VAL) {
>>> +               dev_err(pdma->dev,
>>> +                       "Failed to release DMA memory from shutdown\n");
>>> +               return -ENODEV;
>>> +       }
>>> +
>>> +       return 0;
>>> +}
>>> +
>>> +static int xgene_dma_request_irqs(struct xgene_dma *pdma)
>>> +{
>>> +       struct xgene_dma_chan *chan;
>>> +       int ret, i, j;
>>> +
>>> +       /* Register DMA error irq */
>>> +       ret = devm_request_irq(pdma->dev, pdma->err_irq, xgene_dma_err_isr,
>>> +                              0, "dma_error", pdma);
>>> +       if (ret) {
>>> +               dev_err(pdma->dev,
>>> +                       "Failed to register error IRQ %d\n", pdma->err_irq);
>>> +               return ret;
>>> +       }
>>> +
>>> +       /* Register DMA channel rx irq */
>>> +       for (i = 0; i < XGENE_DMA_MAX_CHANNEL; i++) {
>>> +               chan = &pdma->chan[i];
>>> +               ret = devm_request_irq(chan->dev, chan->rx_irq,
>>> +                                      xgene_dma_chan_ring_isr,
>>> +                                      0, chan->name, chan);
>>> +               if (ret) {
>>> +                       chan_err(chan, "Failed to register Rx IRQ %d\n",
>>> +                                chan->rx_irq);
>>> +                       devm_free_irq(pdma->dev, pdma->err_irq, pdma);
>>> +
>>> +                       for (j = 0; j < i; j++) {
>>> +                               chan = &pdma->chan[i];
>>> +                               devm_free_irq(chan->dev, chan->rx_irq, chan);
>>> +                       }
>>> +
>>> +                       return ret;
>>> +               }
>>> +       }
>>> +
>>> +       return 0;
>>> +}
>>> +
>>> +static void xgene_dma_free_irqs(struct xgene_dma *pdma)
>>> +{
>>> +       struct xgene_dma_chan *chan;
>>> +       int i;
>>> +
>>> +       /* Free DMA device error irq */
>>> +       devm_free_irq(pdma->dev, pdma->err_irq, pdma);
>>> +
>>> +       for (i = 0; i < XGENE_DMA_MAX_CHANNEL; i++) {
>>> +               chan = &pdma->chan[i];
>>> +               devm_free_irq(chan->dev, chan->rx_irq, chan);
>>> +       }
>>> +}
>>> +
>>> +static void xgene_dma_set_caps(struct xgene_dma_chan *chan,
>>> +                              struct dma_device *dma_dev)
>>> +{
>>> +       /* Initialize DMA device capability mask */
>>> +       dma_cap_zero(dma_dev->cap_mask);
>>> +
>>> +       /* Set DMA device capability */
>>> +       dma_cap_set(DMA_MEMCPY, dma_dev->cap_mask);
>>> +       dma_cap_set(DMA_SG, dma_dev->cap_mask);
>>> +
>>> +       /* Basically here, the X-Gene SoC DMA engine channel 0 supports XOR
>>> +        * and channel 1 supports XOR, PQ both. First thing here is we have
>>> +        * mechanism in hw to enable/disable PQ/XOR supports on channel 1,
>>> +        * we can make sure this by reading SoC Efuse register.
>>> +        * Second thing, we have hw errata that if we run channel 0 and
>>> +        * channel 1 simultaneously with executing XOR and PQ request,
>>> +        * suddenly DMA engine hangs, So here we enable XOR on channel 0 only
>>> +        * if XOR and PQ supports on channel 1 is disabled.
>>> +        */
>>> +       if ((chan->id == XGENE_DMA_PQ_CHANNEL) &&
>>> +           is_pq_enabled(chan->pdma)) {
>>> +               dma_cap_set(DMA_PQ, dma_dev->cap_mask);
>>> +               dma_cap_set(DMA_XOR, dma_dev->cap_mask);
>>> +       } else if ((chan->id == XGENE_DMA_XOR_CHANNEL) &&
>>> +                  !is_pq_enabled(chan->pdma)) {
>>> +               dma_cap_set(DMA_XOR, dma_dev->cap_mask);
>>> +       }
>>> +
>>> +       /* Set base and prep routines */
>>> +       dma_dev->dev = chan->dev;
>>> +       dma_dev->device_alloc_chan_resources = xgene_dma_alloc_chan_resources;
>>> +       dma_dev->device_free_chan_resources = xgene_dma_free_chan_resources;
>>> +       dma_dev->device_issue_pending = xgene_dma_issue_pending;
>>> +       dma_dev->device_tx_status = xgene_dma_tx_status;
>>> +       dma_dev->device_prep_dma_memcpy = xgene_dma_prep_memcpy;
>>> +       dma_dev->device_prep_dma_sg = xgene_dma_prep_sg;
>>> +
>>> +       if (dma_has_cap(DMA_XOR, dma_dev->cap_mask)) {
>>> +               dma_dev->device_prep_dma_xor = xgene_dma_prep_xor;
>>> +               dma_dev->max_xor = XGENE_DMA_MAX_XOR_SRC;
>>> +               dma_dev->xor_align = XGENE_DMA_XOR_ALIGNMENT;
>>> +       }
>>> +
>>> +       if (dma_has_cap(DMA_PQ, dma_dev->cap_mask)) {
>>> +               dma_dev->device_prep_dma_pq = xgene_dma_prep_pq;
>>> +               dma_dev->max_pq = XGENE_DMA_MAX_XOR_SRC;
>>> +               dma_dev->pq_align = XGENE_DMA_XOR_ALIGNMENT;
>>> +       }
>>> +}
>>> +
>>> +static int xgene_dma_async_register(struct xgene_dma *pdma, int id)
>>> +{
>>> +       struct xgene_dma_chan *chan = &pdma->chan[id];
>>> +       struct dma_device *dma_dev = &pdma->dma_dev[id];
>>> +       int ret;
>>> +
>>> +       chan->dma_chan.device = dma_dev;
>>> +
>>> +       spin_lock_init(&chan->lock);
>>> +       INIT_LIST_HEAD(&chan->ld_pending);
>>> +       INIT_LIST_HEAD(&chan->ld_running);
>>> +       INIT_LIST_HEAD(&chan->ld_completed);
>>> +       tasklet_init(&chan->tasklet, xgene_dma_tasklet_cb,
>>> +                    (unsigned long)chan);
>>> +
>>> +       chan->pending = 0;
>>> +       chan->desc_pool = NULL;
>>> +       dma_cookie_init(&chan->dma_chan);
>>> +
>>> +       /* Setup dma device capabilities and prep routines */
>>> +       xgene_dma_set_caps(chan, dma_dev);
>>> +
>>> +       /* Initialize DMA device list head */
>>> +       INIT_LIST_HEAD(&dma_dev->channels);
>>> +       list_add_tail(&chan->dma_chan.device_node, &dma_dev->channels);
>>> +
>>> +       /* Register with Linux async DMA framework*/
>>> +       ret = dma_async_device_register(dma_dev);
>>> +       if (ret) {
>>> +               chan_err(chan, "Failed to register async device %d", ret);
>>> +               tasklet_kill(&chan->tasklet);
>>> +
>>> +               return ret;
>>> +       }
>>> +
>>> +       /* DMA capability info */
>>> +       dev_info(pdma->dev,
>>> +                "%s: CAPABILITY ( %s%s%s%s)\n", dma_chan_name(&chan->dma_chan),
>>> +                dma_has_cap(DMA_MEMCPY, dma_dev->cap_mask) ? "MEMCPY " : "",
>>> +                dma_has_cap(DMA_SG, dma_dev->cap_mask) ? "SGCPY " : "",
>>> +                dma_has_cap(DMA_XOR, dma_dev->cap_mask) ? "XOR " : "",
>>> +                dma_has_cap(DMA_PQ, dma_dev->cap_mask) ? "PQ " : "");
>>> +
>>> +       return 0;
>>> +}
>>> +
>>> +static int xgene_dma_init_async(struct xgene_dma *pdma)
>>> +{
>>> +       int ret, i, j;
>>> +
>>> +       for (i = 0; i < XGENE_DMA_MAX_CHANNEL ; i++) {
>>> +               ret = xgene_dma_async_register(pdma, i);
>>> +               if (ret) {
>>> +                       for (j = 0; j < i; j++) {
>>> +                               dma_async_device_unregister(&pdma->dma_dev[j]);
>>> +                               tasklet_kill(&pdma->chan[j].tasklet);
>>> +                       }
>>> +
>>> +                       return ret;
>>> +               }
>>> +       }
>>> +
>>> +       return ret;
>>> +}
>>> +
>>> +static void xgene_dma_async_unregister(struct xgene_dma *pdma)
>>> +{
>>> +       int i;
>>> +
>>> +       for (i = 0; i < XGENE_DMA_MAX_CHANNEL; i++)
>>> +               dma_async_device_unregister(&pdma->dma_dev[i]);
>>> +}
>>> +
>>> +static void xgene_dma_init_channels(struct xgene_dma *pdma)
>>> +{
>>> +       struct xgene_dma_chan *chan;
>>> +       int i;
>>> +
>>> +       pdma->ring_num = XGENE_DMA_RING_NUM;
>>> +
>>> +       for (i = 0; i < XGENE_DMA_MAX_CHANNEL; i++) {
>>> +               chan = &pdma->chan[i];
>>> +               chan->dev = pdma->dev;
>>> +               chan->pdma = pdma;
>>> +               chan->id = i;
>>> +               sprintf(chan->name, "dmachan%d", chan->id);
>>> +       }
>>> +}
>>> +
>>> +static int xgene_dma_get_resources(struct platform_device *pdev,
>>> +                                  struct xgene_dma *pdma)
>>> +{
>>> +       struct resource *res;
>>> +       int irq, i;
>>> +
>>> +       /* Get DMA csr region */
>>> +       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>>> +       if (!res) {
>>> +               dev_err(&pdev->dev, "Failed to get csr region\n");
>>> +               return -ENXIO;
>>> +       }
>>> +
>>> +       pdma->csr_dma = devm_ioremap(&pdev->dev, res->start,
>>> +                                    resource_size(res));
>>> +       if (IS_ERR(pdma->csr_dma)) {
>>> +               dev_err(&pdev->dev, "Failed to ioremap csr region");
>>> +               return PTR_ERR(pdma->csr_dma);
>>> +       }
>>> +
>>> +       /* Get DMA ring csr region */
>>> +       res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
>>> +       if (!res) {
>>> +               dev_err(&pdev->dev, "Failed to get ring csr region\n");
>>> +               return -ENXIO;
>>> +       }
>>> +
>>> +       pdma->csr_ring =  devm_ioremap(&pdev->dev, res->start,
>>> +                                      resource_size(res));
>>> +       if (IS_ERR(pdma->csr_ring)) {
>>> +               dev_err(&pdev->dev, "Failed to ioremap ring csr region");
>>> +               return PTR_ERR(pdma->csr_ring);
>>> +       }
>>> +
>>> +       /* Get DMA ring cmd csr region */
>>> +       res = platform_get_resource(pdev, IORESOURCE_MEM, 2);
>>> +       if (!res) {
>>> +               dev_err(&pdev->dev, "Failed to get ring cmd csr region\n");
>>> +               return -ENXIO;
>>> +       }
>>> +
>>> +       pdma->csr_ring_cmd = devm_ioremap(&pdev->dev, res->start,
>>> +                                         resource_size(res));
>>> +       if (IS_ERR(pdma->csr_ring_cmd)) {
>>> +               dev_err(&pdev->dev, "Failed to ioremap ring cmd csr region");
>>> +               return PTR_ERR(pdma->csr_ring_cmd);
>>> +       }
>>> +
>>> +       /* Get efuse csr region */
>>> +       res = platform_get_resource(pdev, IORESOURCE_MEM, 3);
>>> +       if (!res) {
>>> +               dev_err(&pdev->dev, "Failed to get efuse csr region\n");
>>> +               return -ENXIO;
>>> +       }
>>> +
>>> +       pdma->csr_efuse = devm_ioremap(&pdev->dev, res->start,
>>> +                                      resource_size(res));
>>> +       if (IS_ERR(pdma->csr_efuse)) {
>>> +               dev_err(&pdev->dev, "Failed to ioremap efuse csr region");
>>> +               return PTR_ERR(pdma->csr_efuse);
>>> +       }
>>> +
>>> +       /* Get DMA error interrupt */
>>> +       irq = platform_get_irq(pdev, 0);
>>> +       if (irq <= 0) {
>>> +               dev_err(&pdev->dev, "Failed to get Error IRQ\n");
>>> +               return -ENXIO;
>>> +       }
>>> +
>>> +       pdma->err_irq = irq;
>>> +
>>> +       /* Get DMA Rx ring descriptor interrupts for all DMA channels */
>>> +       for (i = 1; i <= XGENE_DMA_MAX_CHANNEL; i++) {
>>> +               irq = platform_get_irq(pdev, i);
>>> +               if (irq <= 0) {
>>> +                       dev_err(&pdev->dev, "Failed to get Rx IRQ\n");
>>> +                       return -ENXIO;
>>> +               }
>>> +
>>> +               pdma->chan[i - 1].rx_irq = irq;
>>> +       }
>>> +
>>> +       return 0;
>>> +}
>>> +
>>> +static int xgene_dma_probe(struct platform_device *pdev)
>>> +{
>>> +       struct xgene_dma *pdma;
>>> +       int ret, i;
>>> +
>>> +       pdma = devm_kzalloc(&pdev->dev, sizeof(*pdma), GFP_KERNEL);
>>> +       if (!pdma)
>>> +               return -ENOMEM;
>>> +
>>> +       pdma->dev = &pdev->dev;
>>> +       platform_set_drvdata(pdev, pdma);
>>> +
>>> +       ret = xgene_dma_get_resources(pdev, pdma);
>>> +       if (ret)
>>> +               return ret;
>>> +
>>> +       pdma->clk = devm_clk_get(&pdev->dev, NULL);
>>> +       if (IS_ERR(pdma->clk)) {
>>> +               dev_err(&pdev->dev, "Failed to get clk\n");
>>> +               return PTR_ERR(pdma->clk);
>>> +       }
>>> +
>>> +       /* Enable clk before accessing registers */
>>> +       ret = clk_prepare_enable(pdma->clk);
>>> +       if (ret) {
>>> +               dev_err(&pdev->dev, "Failed to enable clk %d\n", ret);
>>> +               return ret;
>>> +       }
>>> +
>>> +       /* Remove DMA RAM out of shutdown */
>>> +       ret = xgene_dma_init_mem(pdma);
>>> +       if (ret)
>>> +               goto err_clk_enable;
>>> +
>>> +       ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(42));
>>> +       if (ret) {
>>> +               dev_err(&pdev->dev, "No usable DMA configuration\n");
>>> +               goto err_dma_mask;
>>> +       }
>>> +
>>> +       /* Initialize DMA channels software state */
>>> +       xgene_dma_init_channels(pdma);
>>> +
>>> +       /* Configue DMA rings */
>>> +       ret = xgene_dma_init_rings(pdma);
>>> +       if (ret)
>>> +               goto err_clk_enable;
>>> +
>>> +       ret = xgene_dma_request_irqs(pdma);
>>> +       if (ret)
>>> +               goto err_request_irq;
>>> +
>>> +       /* Configure and enable DMA engine */
>>> +       xgene_dma_init_hw(pdma);
>>> +
>>> +       /* Register DMA device with linux async framework */
>>> +       ret = xgene_dma_init_async(pdma);
>>> +       if (ret)
>>> +               goto err_async_init;
>>> +
>>> +       return 0;
>>> +
>>> +err_async_init:
>>> +       xgene_dma_free_irqs(pdma);
>>> +
>>> +err_request_irq:
>>> +       for (i = 0; i < XGENE_DMA_MAX_CHANNEL; i++)
>>> +               xgene_dma_delete_chan_rings(&pdma->chan[i]);
>>> +
>>> +err_dma_mask:
>>> +err_clk_enable:
>>> +       clk_disable_unprepare(pdma->clk);
>>> +
>>> +       return ret;
>>> +}
>>> +
>>> +static int xgene_dma_remove(struct platform_device *pdev)
>>> +{
>>> +       struct xgene_dma *pdma = platform_get_drvdata(pdev);
>>> +       struct xgene_dma_chan *chan;
>>> +       int i;
>>> +
>>> +       xgene_dma_async_unregister(pdma);
>>> +
>>> +       /* Mask interrupts and disable DMA engine */
>>> +       xgene_dma_mask_interrupts(pdma);
>>> +       xgene_dma_disable(pdma);
>>> +       xgene_dma_free_irqs(pdma);
>>> +
>>> +       for (i = 0; i < XGENE_DMA_MAX_CHANNEL; i++) {
>>> +               chan = &pdma->chan[i];
>>> +               tasklet_kill(&chan->tasklet);
>>> +               xgene_dma_delete_chan_rings(chan);
>>> +       }
>>> +
>>> +       clk_disable_unprepare(pdma->clk);
>>> +
>>> +       return 0;
>>> +}
>>> +
>>> +static const struct of_device_id xgene_dma_of_match_ptr[] = {
>>> +       {.compatible = "apm,xgene-storm-dma",},
>>> +       {},
>>> +};
>>> +MODULE_DEVICE_TABLE(of, xgene_dma_of_match_ptr);
>>> +
>>> +static struct platform_driver xgene_dma_driver = {
>>> +       .probe = xgene_dma_probe,
>>> +       .remove = xgene_dma_remove,
>>> +       .driver = {
>>> +               .name = "X-Gene-DMA",
>>> +               .owner = THIS_MODULE,
>>> +               .of_match_table = xgene_dma_of_match_ptr,
>>> +       },
>>> +};
>>> +
>>> +module_platform_driver(xgene_dma_driver);
>>> +
>>> +MODULE_DESCRIPTION("APM X-Gene SoC DMA driver");
>>> +MODULE_AUTHOR("Rameshwar Prasad Sahu <[e-mail]>");
>>> +MODULE_AUTHOR("Loc Ho <[e-mail]>");
>>> +MODULE_LICENSE("GPL");
>>> +MODULE_VERSION("1.0");
>>> --
>>> 1.8.2.1
>>>
>>
>>
>> Any comments on above patch....
>
> Pinging again...

Can you please review the above patch, so that I can go ahead for next
version if you still feel needs changes.
>
> Thanks,
> Ram
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Patch

diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
index a874b6e..a271346 100644
--- a/drivers/dma/Kconfig
+++ b/drivers/dma/Kconfig
@@ -425,6 +425,14 @@  config IMG_MDC_DMA
 	help
 	  Enable support for the IMG multi-threaded DMA controller (MDC).

+config XGENE_DMA
+	tristate "APM X-Gene DMA support"
+	select DMA_ENGINE
+	select DMA_ENGINE_RAID
+	select ASYNC_TX_ENABLE_CHANNEL_SWITCH
+	help
+	  Enable support for the APM X-Gene SoC DMA engine.
+
 config DMA_ENGINE
 	bool

diff --git a/drivers/dma/Makefile b/drivers/dma/Makefile
index f915f61..06c1576 100644
--- a/drivers/dma/Makefile
+++ b/drivers/dma/Makefile
@@ -51,3 +51,4 @@  obj-$(CONFIG_INTEL_MIC_X100_DMA) += mic_x100_dma.o
 obj-$(CONFIG_NBPFAXI_DMA) += nbpfaxi.o
 obj-$(CONFIG_DMA_SUN6I) += sun6i-dma.o
 obj-$(CONFIG_IMG_MDC_DMA) += img-mdc-dma.o
+obj-$(CONFIG_XGENE_DMA) += xgene-dma.o
diff --git a/drivers/dma/xgene-dma.c b/drivers/dma/xgene-dma.c
new file mode 100755
index 0000000..2383528
--- /dev/null
+++ b/drivers/dma/xgene-dma.c
@@ -0,0 +1,2090 @@ 
+/*
+ * Applied Micro X-Gene SoC DMA engine Driver
+ *
+ * Copyright (c) 2015, Applied Micro Circuits Corporation
+ * Authors: Rameshwar Prasad Sahu <[e-mail]>
+ *	    Loc Ho <[e-mail]>
+ *
+ * This program is free software; you can redistribute  it and/or modify it
+ * under  the terms of  the GNU General  Public License as published by the
+ * Free Software Foundation;  either version 2 of the  License, or (at your
+ * option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * NOTE: PM support is currently not available.
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/dma-mapping.h>
+#include <linux/dmaengine.h>
+#include <linux/dmapool.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+
+#include "dmaengine.h"
+
+/* X-Gene DMA ring csr registers and bit definations */
+#define XGENE_DMA_RING_CONFIG			0x04
+#define XGENE_DMA_RING_ENABLE			BIT(31)
+#define XGENE_DMA_RING_ID			0x08
+#define XGENE_DMA_RING_ID_SETUP(v)		((v) | BIT(31))
+#define XGENE_DMA_RING_ID_BUF			0x0C
+#define XGENE_DMA_RING_ID_BUF_SETUP(v)		(((v) << 9) | BIT(21))
+#define XGENE_DMA_RING_THRESLD0_SET1		0x30
+#define XGENE_DMA_RING_THRESLD0_SET1_VAL	0X64
+#define XGENE_DMA_RING_THRESLD1_SET1		0x34
+#define XGENE_DMA_RING_THRESLD1_SET1_VAL	0xC8
+#define XGENE_DMA_RING_HYSTERESIS		0x68
+#define XGENE_DMA_RING_HYSTERESIS_VAL		0xFFFFFFFF
+#define XGENE_DMA_RING_STATE			0x6C
+#define XGENE_DMA_RING_STATE_WR_BASE		0x70
+#define XGENE_DMA_RING_NE_INT_MODE		0x017C
+#define XGENE_DMA_RING_NE_INT_MODE_SET(m, v)	\
+	((m) = ((m) & ~BIT(31 - (v))) | BIT(31 - (v)))
+#define XGENE_DMA_RING_NE_INT_MODE_RESET(m, v)	\
+	((m) &= (~BIT(31 - (v))))
+#define XGENE_DMA_RING_CLKEN			0xC208
+#define XGENE_DMA_RING_SRST			0xC200
+#define XGENE_DMA_RING_MEM_RAM_SHUTDOWN		0xD070
+#define XGENE_DMA_RING_BLK_MEM_RDY		0xD074
+#define XGENE_DMA_RING_BLK_MEM_RDY_VAL		0xFFFFFFFF
+#define XGENE_DMA_RING_DESC_CNT(v)		(((v) & 0x0001FFFE) >> 1)
+#define XGENE_DMA_RING_ID_GET(owner, num)	(((owner) << 6) | (num))
+#define XGENE_DMA_RING_DST_ID(v)		((1 << 10) | (v))
+#define XGENE_DMA_RING_CMD_OFFSET		0x2C
+#define XGENE_DMA_RING_CMD_BASE_OFFSET(v)	((v) << 6)
+#define XGENE_DMA_RING_COHERENT_SET(m)		\
+	(((u32 *)(m))[2] |= BIT(4))
+#define XGENE_DMA_RING_ADDRL_SET(m, v)		\
+	(((u32 *)(m))[2] |= (((v) >> 8) << 5))
+#define XGENE_DMA_RING_ADDRH_SET(m, v)		\
+	(((u32 *)(m))[3] |= ((v) >> 35))
+#define XGENE_DMA_RING_ACCEPTLERR_SET(m)	\
+	(((u32 *)(m))[3] |= BIT(19))
+#define XGENE_DMA_RING_SIZE_SET(m, v)		\
+	(((u32 *)(m))[3] |= ((v) << 23))
+#define XGENE_DMA_RING_RECOMBBUF_SET(m)		\
+	(((u32 *)(m))[3] |= BIT(27))
+#define XGENE_DMA_RING_RECOMTIMEOUTL_SET(m)	\
+	(((u32 *)(m))[3] |= (0x7 << 28))
+#define XGENE_DMA_RING_RECOMTIMEOUTH_SET(m)	\
+	(((u32 *)(m))[4] |= 0x3)
+#define XGENE_DMA_RING_SELTHRSH_SET(m)		\
+	(((u32 *)(m))[4] |= BIT(3))
+#define XGENE_DMA_RING_TYPE_SET(m, v)		\
+	(((u32 *)(m))[4] |= ((v) << 19))
+
+/* X-Gene DMA device csr registers and bit definitions */
+#define XGENE_DMA_IPBRR				0x0
+#define XGENE_DMA_DEV_ID_RD(v)			((v) & 0x00000FFF)
+#define XGENE_DMA_BUS_ID_RD(v)			(((v) >> 12) & 3)
+#define XGENE_DMA_REV_NO_RD(v)			(((v) >> 14) & 3)
+#define XGENE_DMA_GCR				0x10
+#define XGENE_DMA_CH_SETUP(v)			\
+	((v) = ((v) & ~0x000FFFFF) | 0x000AAFFF)
+#define XGENE_DMA_ENABLE(v)			((v) |= BIT(31))
+#define XGENE_DMA_DISABLE(v)			((v) &= ~BIT(31))
+#define XGENE_DMA_RAID6_CONT			0x14
+#define XGENE_DMA_RAID6_MULTI_CTRL(v)		((v) << 24)
+#define XGENE_DMA_INT				0x70
+#define XGENE_DMA_INT_MASK			0x74
+#define XGENE_DMA_INT_ALL_MASK			0xFFFFFFFF
+#define XGENE_DMA_INT_ALL_UNMASK		0x0
+#define XGENE_DMA_INT_MASK_SHIFT		0x14
+#define XGENE_DMA_RING_INT0_MASK		0x90A0
+#define XGENE_DMA_RING_INT1_MASK		0x90A8
+#define XGENE_DMA_RING_INT2_MASK		0x90B0
+#define XGENE_DMA_RING_INT3_MASK		0x90B8
+#define XGENE_DMA_RING_INT4_MASK		0x90C0
+#define XGENE_DMA_CFG_RING_WQ_ASSOC		0x90E0
+#define XGENE_DMA_ASSOC_RING_MNGR1		0xFFFFFFFF
+#define XGENE_DMA_MEM_RAM_SHUTDOWN		0xD070
+#define XGENE_DMA_BLK_MEM_RDY			0xD074
+#define XGENE_DMA_BLK_MEM_RDY_VAL		0xFFFFFFFF
+
+/* X-Gene SoC EFUSE csr register and bit defination */
+#define XGENE_SOC_JTAG1_SHADOW			0x18
+#define XGENE_DMA_PQ_DISABLE_MASK		BIT(13)
+
+/* X-Gene DMA Descriptor format */
+#define XGENE_DMA_DESC_NV_BIT			BIT_ULL(50)
+#define XGENE_DMA_DESC_IN_BIT			BIT_ULL(55)
+#define XGENE_DMA_DESC_C_BIT			BIT_ULL(63)
+#define XGENE_DMA_DESC_DR_BIT			BIT_ULL(61)
+#define XGENE_DMA_DESC_ELERR_POS		46
+#define XGENE_DMA_DESC_RTYPE_POS		56
+#define XGENE_DMA_DESC_LERR_POS			60
+#define XGENE_DMA_DESC_FLYBY_POS		4
+#define XGENE_DMA_DESC_BUFLEN_POS		48
+#define XGENE_DMA_DESC_HOENQ_NUM_POS		48
+
+#define XGENE_DMA_DESC_NV_SET(m)		\
+	(((u64 *)(m))[0] |= XGENE_DMA_DESC_NV_BIT)
+#define XGENE_DMA_DESC_IN_SET(m)		\
+	(((u64 *)(m))[0] |= XGENE_DMA_DESC_IN_BIT)
+#define XGENE_DMA_DESC_RTYPE_SET(m, v)		\
+	(((u64 *)(m))[0] |= ((u64)(v) << XGENE_DMA_DESC_RTYPE_POS))
+#define XGENE_DMA_DESC_BUFADDR_SET(m, v)	\
+	(((u64 *)(m))[0] |= (v))
+#define XGENE_DMA_DESC_BUFLEN_SET(m, v)		\
+	(((u64 *)(m))[0] |= ((u64)(v) << XGENE_DMA_DESC_BUFLEN_POS))
+#define XGENE_DMA_DESC_C_SET(m)			\
+	(((u64 *)(m))[1] |= XGENE_DMA_DESC_C_BIT)
+#define XGENE_DMA_DESC_FLYBY_SET(m, v)		\
+	(((u64 *)(m))[2] |= ((v) << XGENE_DMA_DESC_FLYBY_POS))
+#define XGENE_DMA_DESC_MULTI_SET(m, v, i)	\
+	(((u64 *)(m))[2] |= ((u64)(v) << (((i) + 1) * 8)))
+#define XGENE_DMA_DESC_DR_SET(m)		\
+	(((u64 *)(m))[2] |= XGENE_DMA_DESC_DR_BIT)
+#define XGENE_DMA_DESC_DST_ADDR_SET(m, v)	\
+	(((u64 *)(m))[3] |= (v))
+#define XGENE_DMA_DESC_H0ENQ_NUM_SET(m, v)	\
+	(((u64 *)(m))[3] |= ((u64)(v) << XGENE_DMA_DESC_HOENQ_NUM_POS))
+#define XGENE_DMA_DESC_ELERR_RD(m)		\
+	(((m) >> XGENE_DMA_DESC_ELERR_POS) & 0x3)
+#define XGENE_DMA_DESC_LERR_RD(m)		\
+	(((m) >> XGENE_DMA_DESC_LERR_POS) & 0x7)
+#define XGENE_DMA_DESC_STATUS(elerr, lerr)	\
+	(((elerr) << 4) | (lerr))
+
+/* X-Gene DMA descriptor empty s/w signature */
+#define XGENE_DMA_DESC_EMPTY_INDEX		0
+#define XGENE_DMA_DESC_EMPTY_SIGNATURE		~0ULL
+#define XGENE_DMA_DESC_SET_EMPTY(m)		\
+	(((u64 *)(m))[XGENE_DMA_DESC_EMPTY_INDEX] =	\
+	 XGENE_DMA_DESC_EMPTY_SIGNATURE)
+#define XGENE_DMA_DESC_IS_EMPTY(m)		\
+	(((u64 *)(m))[XGENE_DMA_DESC_EMPTY_INDEX] ==	\
+	 XGENE_DMA_DESC_EMPTY_SIGNATURE)
+
+/* X-Gene DMA configurable parameters defines */
+#define XGENE_DMA_RING_NUM		512
+#define XGENE_DMA_BUFNUM		0x0
+#define XGENE_DMA_CPU_BUFNUM		0x18
+#define XGENE_DMA_RING_OWNER_DMA	0x03
+#define XGENE_DMA_RING_OWNER_CPU	0x0F
+#define XGENE_DMA_RING_TYPE_REGULAR	0x01
+#define XGENE_DMA_RING_WQ_DESC_SIZE	32	/* 32 Bytes */
+#define XGENE_DMA_RING_NUM_CONFIG	5
+#define XGENE_DMA_MAX_CHANNEL		4
+#define XGENE_DMA_XOR_CHANNEL		0
+#define XGENE_DMA_PQ_CHANNEL		1
+#define XGENE_DMA_MAX_BYTE_CNT		0x4000	/* 16 KB */
+#define XGENE_DMA_MAX_64B_DESC_BYTE_CNT	0x14000	/* 80 KB */
+#define XGENE_DMA_XOR_ALIGNMENT		6	/* 64 Bytes */
+#define XGENE_DMA_MAX_XOR_SRC		5
+#define XGENE_DMA_16K_BUFFER_LEN_CODE	0x0
+#define XGENE_DMA_INVALID_LEN_CODE	0x7800
+
+/* X-Gene DMA descriptor error codes */
+#define ERR_DESC_AXI			0x01
+#define ERR_BAD_DESC			0x02
+#define ERR_READ_DATA_AXI		0x03
+#define ERR_WRITE_DATA_AXI		0x04
+#define ERR_FBP_TIMEOUT			0x05
+#define ERR_ECC				0x06
+#define ERR_DIFF_SIZE			0x08
+#define ERR_SCT_GAT_LEN			0x09
+#define ERR_CRC_ERR			0x11
+#define ERR_CHKSUM			0x12
+#define ERR_DIF				0x13
+
+/* X-Gene DMA error interrupt codes */
+#define ERR_DIF_SIZE_INT		0x0
+#define ERR_GS_ERR_INT			0x1
+#define ERR_FPB_TIMEO_INT		0x2
+#define ERR_WFIFO_OVF_INT		0x3
+#define ERR_RFIFO_OVF_INT		0x4
+#define ERR_WR_TIMEO_INT		0x5
+#define ERR_RD_TIMEO_INT		0x6
+#define ERR_WR_ERR_INT			0x7
+#define ERR_RD_ERR_INT			0x8
+#define ERR_BAD_DESC_INT		0x9
+#define ERR_DESC_DST_INT		0xA
+#define ERR_DESC_SRC_INT		0xB
+
+/* X-Gene DMA flyby operation code */
+#define FLYBY_2SRC_XOR			0x8
+#define FLYBY_3SRC_XOR			0x9
+#define FLYBY_4SRC_XOR			0xA
+#define FLYBY_5SRC_XOR			0xB
+
+/* X-Gene DMA SW descriptor flags */
+#define XGENE_DMA_FLAG_64B_DESC		BIT(0)
+
+/* Define to dump X-Gene DMA descriptor */
+#define XGENE_DMA_DESC_DUMP(desc, m)	\
+	print_hex_dump(KERN_ERR, (m),	\
+			DUMP_PREFIX_ADDRESS, 16, 8, (desc), 32, 0)
+
+#define to_dma_desc_sw(tx)		\
+	container_of(tx, struct xgene_dma_desc_sw, tx)
+#define to_dma_chan(dchan)		\
+	container_of(dchan, struct xgene_dma_chan, dma_chan)
+
+#define chan_dbg(chan, fmt, arg...)	\
+	dev_dbg(chan->dev, "%s: " fmt, chan->name, ##arg)
+#define chan_err(chan, fmt, arg...)	\
+	dev_err(chan->dev, "%s: " fmt, chan->name, ##arg)
+
+struct xgene_dma_desc_hw {
+	u64 m0;
+	u64 m1;
+	u64 m2;
+	u64 m3;
+};
+
+enum xgene_dma_ring_cfgsize {
+	XGENE_DMA_RING_CFG_SIZE_512B,
+	XGENE_DMA_RING_CFG_SIZE_2KB,
+	XGENE_DMA_RING_CFG_SIZE_16KB,
+	XGENE_DMA_RING_CFG_SIZE_64KB,
+	XGENE_DMA_RING_CFG_SIZE_512KB,
+	XGENE_DMA_RING_CFG_SIZE_INVALID
+};
+
+struct xgene_dma_ring {
+	struct xgene_dma *pdma;
+	u8 buf_num;
+	u16 id;
+	u16 num;
+	u16 head;
+	u16 owner;
+	u16 slots;
+	u16 dst_ring_num;
+	u32 size;
+	void __iomem *cmd;
+	void __iomem *cmd_base;
+	dma_addr_t desc_paddr;
+	u32 state[XGENE_DMA_RING_NUM_CONFIG];
+	enum xgene_dma_ring_cfgsize cfgsize;
+	union {
+		void *desc_vaddr;
+		struct xgene_dma_desc_hw *desc_hw;
+	};
+};
+
+struct xgene_dma_desc_sw {
+	struct xgene_dma_desc_hw desc1;
+	struct xgene_dma_desc_hw desc2;
+	u32 flags;
+	struct list_head node;
+	struct list_head tx_list;
+	struct dma_async_tx_descriptor tx;
+};
+
+/**
+ * struct xgene_dma_chan - internal representation of an X-Gene DMA channel
+ * @dma_chan: dmaengine channel object member
+ * @pdma: X-Gene DMA device structure reference
+ * @dev: struct device reference for dma mapping api
+ * @id: raw id of this channel
+ * @rx_irq: channel IRQ
+ * @name: name of X-Gene DMA channel
+ * @lock: serializes enqueue/dequeue operations to the descriptor pool
+ * @pending: number of transaction request pushed to DMA controller for
+ *	execution, but still waiting for completion,
+ * @max_outstanding: max number of outstanding request we can push to channel
+ * @ld_pending: descriptors which are queued to run, but have not yet been
+ *	submitted to the hardware for execution
+ * @ld_running: descriptors which are currently being executing by the hardware
+ * @ld_completed: descriptors which have finished execution by the hardware.
+ *	These descriptors have already had their cleanup actions run. They
+ *	are waiting for the ACK bit to be set by the async tx API.
+ * @desc_pool: descriptor pool for DMA operations
+ * @tasklet: bottom half where all completed descriptors cleans
+ * @tx_ring: transmit ring descriptor that we use to prepare actual
+ *	descriptors for further executions
+ * @rx_ring: receive ring descriptor that we use to get completed DMA
+ *	descriptors during cleanup time
+ */
+struct xgene_dma_chan {
+	struct dma_chan dma_chan;
+	struct xgene_dma *pdma;
+	struct device *dev;
+	int id;
+	int rx_irq;
+	char name[8];
+	spinlock_t lock;
+	int pending;
+	int max_outstanding;
+	struct list_head ld_pending;
+	struct list_head ld_running;
+	struct list_head ld_completed;
+	struct dma_pool *desc_pool;
+	struct tasklet_struct tasklet;
+	struct xgene_dma_ring tx_ring;
+	struct xgene_dma_ring rx_ring;
+};
+
+/**
+ * struct xgene_dma - internal representation of an X-Gene DMA device
+ * @err_irq: DMA error irq number
+ * @ring_num: start id number for DMA ring
+ * @csr_dma: base for DMA register access
+ * @csr_ring: base for DMA ring register access
+ * @csr_ring_cmd: base for DMA ring command register access
+ * @csr_efuse: base for efuse register access
+ * @dma_dev: embedded struct dma_device
+ * @chan: reference to X-Gene DMA channels
+ */
+struct xgene_dma {
+	struct device *dev;
+	struct clk *clk;
+	int err_irq;
+	int ring_num;
+	void __iomem *csr_dma;
+	void __iomem *csr_ring;
+	void __iomem *csr_ring_cmd;
+	void __iomem *csr_efuse;
+	struct dma_device dma_dev[XGENE_DMA_MAX_CHANNEL];
+	struct xgene_dma_chan chan[XGENE_DMA_MAX_CHANNEL];
+};
+
+static const char * const xgene_dma_desc_err[] = {
+	[ERR_DESC_AXI] = "AXI error when reading src/dst link list",
+	[ERR_BAD_DESC] = "ERR or El_ERR fields not set to zero in desc",
+	[ERR_READ_DATA_AXI] = "AXI error when reading data",
+	[ERR_WRITE_DATA_AXI] = "AXI error when writing data",
+	[ERR_FBP_TIMEOUT] = "Timeout on bufpool fetch",
+	[ERR_ECC] = "ECC double bit error",
+	[ERR_DIFF_SIZE] = "Bufpool too small to hold all the DIF result",
+	[ERR_SCT_GAT_LEN] = "Gather and scatter data length not same",
+	[ERR_CRC_ERR] = "CRC error",
+	[ERR_CHKSUM] = "Checksum error",
+	[ERR_DIF] = "DIF error",
+};
+
+static const char * const xgene_dma_err[] = {
+	[ERR_DIF_SIZE_INT] = "DIF size error",
+	[ERR_GS_ERR_INT] = "Gather scatter not same size error",
+	[ERR_FPB_TIMEO_INT] = "Free pool time out error",
+	[ERR_WFIFO_OVF_INT] = "Write FIFO over flow error",
+	[ERR_RFIFO_OVF_INT] = "Read FIFO over flow error",
+	[ERR_WR_TIMEO_INT] = "Write time out error",
+	[ERR_RD_TIMEO_INT] = "Read time out error",
+	[ERR_WR_ERR_INT] = "HBF bus write error",
+	[ERR_RD_ERR_INT] = "HBF bus read error",
+	[ERR_BAD_DESC_INT] = "Ring descriptor HE0 not set error",
+	[ERR_DESC_DST_INT] = "HFB reading dst link address error",
+	[ERR_DESC_SRC_INT] = "HFB reading src link address error",
+};
+
+static bool is_pq_enabled(struct xgene_dma *pdma)
+{
+	u32 val;
+
+	val = ioread32(pdma->csr_efuse + XGENE_SOC_JTAG1_SHADOW);
+	return !(val & XGENE_DMA_PQ_DISABLE_MASK);
+}
+
+static void xgene_dma_cpu_to_le64(u64 *desc, int count)
+{
+	int i;
+
+	for (i = 0; i < count; i++)
+		desc[i] = cpu_to_le64(desc[i]);
+}
+
+static u16 xgene_dma_encode_len(u32 len)
+{
+	return (len < XGENE_DMA_MAX_BYTE_CNT) ?
+		len : XGENE_DMA_16K_BUFFER_LEN_CODE;
+}
+
+static u8 xgene_dma_encode_xor_flyby(u32 src_cnt)
+{
+	static u8 flyby_type[] = {
+		FLYBY_2SRC_XOR, /* Dummy */
+		FLYBY_2SRC_XOR, /* Dummy */
+		FLYBY_2SRC_XOR,
+		FLYBY_3SRC_XOR,
+		FLYBY_4SRC_XOR,
+		FLYBY_5SRC_XOR
+	};
+
+	return flyby_type[src_cnt];
+}
+
+static u32 xgene_dma_ring_desc_cnt(struct xgene_dma_ring *ring)
+{
+	u32 __iomem *cmd_base = ring->cmd_base;
+	u32 ring_state = ioread32(&cmd_base[1]);
+
+	return XGENE_DMA_RING_DESC_CNT(ring_state);
+}
+
+static void xgene_dma_set_src_buffer(void *ext8, size_t *len,
+				     dma_addr_t *paddr)
+{
+	size_t nbytes = (*len < XGENE_DMA_MAX_BYTE_CNT) ?
+			*len : XGENE_DMA_MAX_BYTE_CNT;
+
+	XGENE_DMA_DESC_BUFADDR_SET(ext8, *paddr);
+	XGENE_DMA_DESC_BUFLEN_SET(ext8, xgene_dma_encode_len(nbytes));
+	*len -= nbytes;
+	*paddr += nbytes;
+}
+
+static void xgene_dma_invalidate_buffer(void *ext8)
+{
+	XGENE_DMA_DESC_BUFLEN_SET(ext8, XGENE_DMA_INVALID_LEN_CODE);
+}
+
+static void *xgene_dma_lookup_ext8(u64 *desc, int idx)
+{
+	return (idx % 2) ? (desc + idx - 1) : (desc + idx + 1);
+}
+
+static void xgene_dma_init_desc(void *desc, u16 dst_ring_num)
+{
+	XGENE_DMA_DESC_C_SET(desc); /* Coherent IO */
+	XGENE_DMA_DESC_IN_SET(desc);
+	XGENE_DMA_DESC_H0ENQ_NUM_SET(desc, dst_ring_num);
+	XGENE_DMA_DESC_RTYPE_SET(desc, XGENE_DMA_RING_OWNER_DMA);
+}
+
+static void xgene_dma_prep_cpy_desc(struct xgene_dma_chan *chan,
+				    struct xgene_dma_desc_sw *desc_sw,
+				    dma_addr_t dst, dma_addr_t src,
+				    size_t len)
+{
+	void *desc1, *desc2;
+	int i;
+
+	/* Get 1st descriptor */
+	desc1 = &desc_sw->desc1;
+	xgene_dma_init_desc(desc1, chan->tx_ring.dst_ring_num);
+
+	/* Set destination address */
+	XGENE_DMA_DESC_DR_SET(desc1);
+	XGENE_DMA_DESC_DST_ADDR_SET(desc1, dst);
+
+	/* Set 1st source address */
+	xgene_dma_set_src_buffer(desc1 + 8, &len, &src);
+
+	if (len <= 0) {
+		desc2 = NULL;
+		goto skip_additional_src;
+	}
+
+	/*
+	 * We need to split this source buffer,
+	 * and need to use 2nd descriptor
+	 */
+	desc2 = &desc_sw->desc2;
+	XGENE_DMA_DESC_NV_SET(desc1);
+
+	/* Set 2nd to 5th source address */
+	for (i = 0; i < 4 && len; i++)
+		xgene_dma_set_src_buffer(xgene_dma_lookup_ext8(desc2, i),
+					 &len, &src);
+
+	/* Invalidate unused source address field */
+	for (; i < 4; i++)
+		xgene_dma_invalidate_buffer(xgene_dma_lookup_ext8(desc2, i));
+
+	/* Updated flag that we have prepared 64B descriptor */
+	desc_sw->flags |= XGENE_DMA_FLAG_64B_DESC;
+
+skip_additional_src:
+	/* Hardware stores descriptor in little endian format */
+	xgene_dma_cpu_to_le64(desc1, 4);
+	if (desc2)
+		xgene_dma_cpu_to_le64(desc2, 4);
+}
+
+static void xgene_dma_prep_xor_desc(struct xgene_dma_chan *chan,
+				    struct xgene_dma_desc_sw *desc_sw,
+				    dma_addr_t *dst, dma_addr_t *src,
+				    u32 src_cnt, size_t *nbytes,
+				    const u8 *scf)
+{
+	void *desc1, *desc2;
+	size_t len = *nbytes;
+	int i;
+
+	desc1 = &desc_sw->desc1;
+	desc2 = &desc_sw->desc2;
+
+	/* Initialize DMA descriptor */
+	xgene_dma_init_desc(desc1, chan->tx_ring.dst_ring_num);
+
+	/* Set destination address */
+	XGENE_DMA_DESC_DR_SET(desc1);
+	XGENE_DMA_DESC_DST_ADDR_SET(desc1, *dst);
+
+	/* We have multiple source addresses, so need to set NV bit*/
+	XGENE_DMA_DESC_NV_SET(desc1);
+
+	/* Set flyby opcode */
+	XGENE_DMA_DESC_FLYBY_SET(desc1, xgene_dma_encode_xor_flyby(src_cnt));
+
+	/* Set 1st to 5th source addresses */
+	for (i = 0; i < src_cnt; i++) {
+		len = *nbytes;
+		xgene_dma_set_src_buffer((i == 0) ? (desc1 + 8) :
+					 xgene_dma_lookup_ext8(desc2, i - 1),
+					 &len, &src[i]);
+		XGENE_DMA_DESC_MULTI_SET(desc1, scf[i], i);
+	}
+
+	/* Hardware stores descriptor in little endian format */
+	xgene_dma_cpu_to_le64(desc1, 4);
+	xgene_dma_cpu_to_le64(desc2, 4);
+
+	/* Update meta data */
+	*nbytes = len;
+	*dst += XGENE_DMA_MAX_BYTE_CNT;
+
+	/* We need always 64B descriptor to perform xor or pq operations */
+	desc_sw->flags |= XGENE_DMA_FLAG_64B_DESC;
+}
+
+static dma_cookie_t xgene_dma_tx_submit(struct dma_async_tx_descriptor *tx)
+{
+	struct xgene_dma_desc_sw *desc;
+	struct xgene_dma_chan *chan;
+	dma_cookie_t cookie;
+
+	if (unlikely(!tx))
+		return -EINVAL;
+
+	chan = to_dma_chan(tx->chan);
+	desc = to_dma_desc_sw(tx);
+
+	spin_lock_bh(&chan->lock);
+
+	cookie = dma_cookie_assign(tx);
+
+	/* Add this transaction list onto the tail of the pending queue */
+	list_splice_tail_init(&desc->tx_list, &chan->ld_pending);
+
+	spin_unlock_bh(&chan->lock);
+
+	return cookie;
+}
+
+static void xgene_dma_clean_descriptor(struct xgene_dma_chan *chan,
+				       struct xgene_dma_desc_sw *desc)
+{
+	list_del(&desc->node);
+	chan_dbg(chan, "LD %p free\n", desc);
+	dma_pool_free(chan->desc_pool, desc, desc->tx.phys);
+}
+
+static struct xgene_dma_desc_sw *xgene_dma_alloc_descriptor(
+				 struct xgene_dma_chan *chan)
+{
+	struct xgene_dma_desc_sw *desc;
+	dma_addr_t phys;
+
+	desc = dma_pool_alloc(chan->desc_pool, GFP_NOWAIT, &phys);
+	if (!desc) {
+		chan_err(chan, "Failed to allocate LDs\n");
+		return NULL;
+	}
+
+	memset(desc, 0, sizeof(*desc));
+
+	INIT_LIST_HEAD(&desc->tx_list);
+	desc->tx.phys = phys;
+	desc->tx.tx_submit = xgene_dma_tx_submit;
+	dma_async_tx_descriptor_init(&desc->tx, &chan->dma_chan);
+
+	chan_dbg(chan, "LD %p allocated\n", desc);
+
+	return desc;
+}
+
+/**
+ * xgene_dma_clean_completed_descriptor - free all descriptors which
+ * has been completed and acked
+ * @chan: X-Gene DMA channel
+ *
+ * This function is used on all completed and acked descriptors.
+ */
+static void xgene_dma_clean_completed_descriptor(struct xgene_dma_chan *chan)
+{
+	struct xgene_dma_desc_sw *desc, *_desc;
+
+	/* Run the callback for each descriptor, in order */
+	list_for_each_entry_safe(desc, _desc, &chan->ld_completed, node) {
+		if (async_tx_test_ack(&desc->tx))
+			xgene_dma_clean_descriptor(chan, desc);
+	}
+}
+
+/**
+ * xgene_dma_run_tx_complete_actions - cleanup a single link descriptor
+ * @chan: X-Gene DMA channel
+ * @desc: descriptor to cleanup and free
+ *
+ * This function is used on a descriptor which has been executed by the DMA
+ * controller. It will run any callbacks, submit any dependencies.
+ */
+static void xgene_dma_run_tx_complete_actions(struct xgene_dma_chan *chan,
+					      struct xgene_dma_desc_sw *desc)
+{
+	struct dma_async_tx_descriptor *tx = &desc->tx;
+
+	/*
+	 * If this is not the last transaction in the group,
+	 * then no need to complete cookie and run any callback as
+	 * this is not the tx_descriptor which had been sent to caller
+	 * of this DMA request
+	 */
+
+	if (tx->cookie == 0)
+		return;
+
+	dma_cookie_complete(tx);
+
+	/* Run the link descriptor callback function */
+	if (tx->callback)
+		tx->callback(tx->callback_param);
+
+	dma_descriptor_unmap(tx);
+
+	/* Run any dependencies */
+	dma_run_dependencies(tx);
+}
+
+/**
+ * xgene_dma_clean_running_descriptor - move the completed descriptor from
+ * ld_running to ld_completed
+ * @chan: X-Gene DMA channel
+ * @desc: the descriptor which is completed
+ *
+ * Free the descriptor directly if acked by async_tx api,
+ * else move it to queue ld_completed.
+ */
+static void xgene_dma_clean_running_descriptor(struct xgene_dma_chan *chan,
+					       struct xgene_dma_desc_sw *desc)
+{
+	/* Remove from the list of running transactions */
+	list_del(&desc->node);
+
+	/*
+	 * the client is allowed to attach dependent operations
+	 * until 'ack' is set
+	 */
+	if (!async_tx_test_ack(&desc->tx)) {
+		/*
+		 * Move this descriptor to the list of descriptors which is
+		 * completed, but still awaiting the 'ack' bit to be set.
+		 */
+		list_add_tail(&desc->node, &chan->ld_completed);
+		return;
+	}
+
+	chan_dbg(chan, "LD %p free\n", desc);
+	dma_pool_free(chan->desc_pool, desc, desc->tx.phys);
+}
+
+static int xgene_chan_xfer_request(struct xgene_dma_ring *ring,
+				   struct xgene_dma_desc_sw *desc_sw)
+{
+	struct xgene_dma_desc_hw *desc_hw;
+
+	/* Check if can push more descriptor to hw for execution */
+	if (xgene_dma_ring_desc_cnt(ring) > (ring->slots - 2))
+		return -EBUSY;
+
+	/* Get hw descriptor from DMA tx ring */
+	desc_hw = &ring->desc_hw[ring->head];
+
+	/*
+	 * Increment the head count to point next
+	 * descriptor for next time
+	 */
+	if (++ring->head == ring->slots)
+		ring->head = 0;
+
+	/* Copy prepared sw descriptor data to hw descriptor */
+	memcpy(desc_hw, &desc_sw->desc1, sizeof(*desc_hw));
+
+	/*
+	 * Check if we have prepared 64B descriptor,
+	 * in this case we need one more hw descriptor
+	 */
+	if (desc_sw->flags & XGENE_DMA_FLAG_64B_DESC) {
+		desc_hw = &ring->desc_hw[ring->head];
+
+		if (++ring->head == ring->slots)
+			ring->head = 0;
+
+		memcpy(desc_hw, &desc_sw->desc2, sizeof(*desc_hw));
+	}
+
+	/* Notify the hw that we have descriptor ready for execution */
+	iowrite32((desc_sw->flags & XGENE_DMA_FLAG_64B_DESC) ?
+		  2 : 1, ring->cmd);
+
+	return 0;
+}
+
+/**
+ * xgene_chan_xfer_ld_pending - push any pending transactions to hw
+ * @chan : X-Gene DMA channel
+ *
+ * LOCKING: must hold chan->desc_lock
+ */
+static void xgene_chan_xfer_ld_pending(struct xgene_dma_chan *chan)
+{
+	struct xgene_dma_desc_sw *desc_sw, *_desc_sw;
+	int ret;
+
+	/*
+	 * If the list of pending descriptors is empty, then we
+	 * don't need to do any work at all
+	 */
+	if (list_empty(&chan->ld_pending)) {
+		chan_dbg(chan, "No pending LDs\n");
+		return;
+	}
+
+	/*
+	 * Move elements from the queue of pending transactions onto the list
+	 * of running transactions and push it to hw for further executions
+	 */
+	list_for_each_entry_safe(desc_sw, _desc_sw, &chan->ld_pending, node) {
+		/*
+		 * Check if have pushed max number of transactions to hw
+		 * as capable, so let's stop here and will push remaining
+		 * elements from pening ld queue after completing some
+		 * descriptors that we have already pushed
+		 */
+		if (chan->pending >= chan->max_outstanding)
+			return;
+
+		ret = xgene_chan_xfer_request(&chan->tx_ring, desc_sw);
+		if (ret)
+			return;
+
+		/*
+		 * Delete this element from ld pending queue and append it to
+		 * ld running queue
+		 */
+		list_move_tail(&desc_sw->node, &chan->ld_running);
+
+		/* Increment the pending transaction count */
+		chan->pending++;
+	}
+}
+
+/**
+ * xgene_dma_cleanup_descriptors - cleanup link descriptors which are completed
+ * and move them to ld_completed to free until flag 'ack' is set
+ * @chan: X-Gene DMA channel
+ *
+ * This function is used on descriptors which have been executed by the DMA
+ * controller. It will run any callbacks, submit any dependencies, then
+ * free these descriptors if flag 'ack' is set.
+ */
+static void xgene_dma_cleanup_descriptors(struct xgene_dma_chan *chan)
+{
+	struct xgene_dma_ring *ring = &chan->rx_ring;
+	struct xgene_dma_desc_sw *desc_sw, *_desc_sw;
+	struct xgene_dma_desc_hw *desc_hw;
+	u8 status;
+
+	/* Clean already completed and acked descriptors */
+	xgene_dma_clean_completed_descriptor(chan);
+
+	/* Run the callback for each descriptor, in order */
+	list_for_each_entry_safe(desc_sw, _desc_sw, &chan->ld_running, node) {
+		/* Get subsequent hw descriptor from DMA rx ring */
+		desc_hw = &ring->desc_hw[ring->head];
+
+		/* Check if this descriptor has been completed */
+		if (unlikely(XGENE_DMA_DESC_IS_EMPTY(desc_hw)))
+			break;
+
+		if (++ring->head == ring->slots)
+			ring->head = 0;
+
+		/* Check if we have any error with DMA transactions */
+		status = XGENE_DMA_DESC_STATUS(
+				XGENE_DMA_DESC_ELERR_RD(le64_to_cpu(
+							desc_hw->m0)),
+				XGENE_DMA_DESC_LERR_RD(le64_to_cpu(
+						       desc_hw->m0)));
+		if (status) {
+			/* Print the DMA error type */
+			chan_err(chan, "%s\n", xgene_dma_desc_err[status]);
+
+			/*
+			 * We have DMA transactions error here. Dump DMA Tx
+			 * and Rx descriptors for this request */
+			XGENE_DMA_DESC_DUMP(&desc_sw->desc1,
+					    "X-Gene DMA TX DESC1: ");
+
+			if (desc_sw->flags & XGENE_DMA_FLAG_64B_DESC)
+				XGENE_DMA_DESC_DUMP(&desc_sw->desc2,
+						    "X-Gene DMA TX DESC2: ");
+
+			XGENE_DMA_DESC_DUMP(desc_hw,
+					    "X-Gene DMA RX ERR DESC: ");
+		}
+
+		/* Notify the hw about this completed descriptor */
+		iowrite32(-1, ring->cmd);
+
+		/* Mark this hw descriptor as processed */
+		XGENE_DMA_DESC_SET_EMPTY(desc_hw);
+
+		xgene_dma_run_tx_complete_actions(chan, desc_sw);
+
+		xgene_dma_clean_running_descriptor(chan, desc_sw);
+
+		/*
+		 * Decrement the pending transaction count
+		 * as we have processed one
+		 */
+		chan->pending--;
+	}
+
+	/*
+	 * Start any pending transactions automatically
+	 * In the ideal case, we keep the DMA controller busy while we go
+	 * ahead and free the descriptors below.
+	 */
+	xgene_chan_xfer_ld_pending(chan);
+}
+
+static int xgene_dma_alloc_chan_resources(struct dma_chan *dchan)
+{
+	struct xgene_dma_chan *chan = to_dma_chan(dchan);
+
+	/* Has this channel already been allocated? */
+	if (chan->desc_pool)
+		return 1;
+
+	chan->desc_pool = dma_pool_create(chan->name, chan->dev,
+					  sizeof(struct xgene_dma_desc_sw),
+					  0, 0);
+	if (!chan->desc_pool) {
+		chan_err(chan, "Failed to allocate descriptor pool\n");
+		return -ENOMEM;
+	}
+
+	chan_dbg(chan, "Allocate descripto pool\n");
+
+	return 1;
+}
+
+/**
+ * xgene_dma_free_desc_list - Free all descriptors in a queue
+ * @chan: X-Gene DMA channel
+ * @list: the list to free
+ *
+ * LOCKING: must hold chan->desc_lock
+ */
+static void xgene_dma_free_desc_list(struct xgene_dma_chan *chan,
+				     struct list_head *list)
+{
+	struct xgene_dma_desc_sw *desc, *_desc;
+
+	list_for_each_entry_safe(desc, _desc, list, node)
+		xgene_dma_clean_descriptor(chan, desc);
+}
+
+static void xgene_dma_free_tx_desc_list(struct xgene_dma_chan *chan,
+					struct list_head *list)
+{
+	struct xgene_dma_desc_sw *desc, *_desc;
+
+	list_for_each_entry_safe(desc, _desc, list, node)
+		xgene_dma_clean_descriptor(chan, desc);
+}
+
+static void xgene_dma_free_chan_resources(struct dma_chan *dchan)
+{
+	struct xgene_dma_chan *chan = to_dma_chan(dchan);
+
+	chan_dbg(chan, "Free all resources\n");
+
+	if (!chan->desc_pool)
+		return;
+
+	spin_lock_bh(&chan->lock);
+
+	/* Process all running descriptor */
+	xgene_dma_cleanup_descriptors(chan);
+
+	/* Clean all link descriptor queues */
+	xgene_dma_free_desc_list(chan, &chan->ld_pending);
+	xgene_dma_free_desc_list(chan, &chan->ld_running);
+	xgene_dma_free_desc_list(chan, &chan->ld_completed);
+
+	spin_unlock_bh(&chan->lock);
+
+	/* Delete this channel DMA pool */
+	dma_pool_destroy(chan->desc_pool);
+	chan->desc_pool = NULL;
+}
+
+static struct dma_async_tx_descriptor *xgene_dma_prep_memcpy(
+	struct dma_chan *dchan, dma_addr_t dst, dma_addr_t src,
+	size_t len, unsigned long flags)
+{
+	struct xgene_dma_desc_sw *first = NULL, *new;
+	struct xgene_dma_chan *chan;
+	size_t copy;
+
+	if (unlikely(!dchan || !len))
+		return NULL;
+
+	chan = to_dma_chan(dchan);
+
+	do {
+		/* Allocate the link descriptor from DMA pool */
+		new = xgene_dma_alloc_descriptor(chan);
+		if (!new)
+			goto fail;
+
+		/* Create the largest transaction possible */
+		copy = min_t(size_t, len, XGENE_DMA_MAX_64B_DESC_BYTE_CNT);
+
+		/* Prepare DMA descriptor */
+		xgene_dma_prep_cpy_desc(chan, new, dst, src, copy);
+
+		if (!first)
+			first = new;
+
+		new->tx.cookie = 0;
+		async_tx_ack(&new->tx);
+
+		/* Update metadata */
+		len -= copy;
+		dst += copy;
+		src += copy;
+
+		/* Insert the link descriptor to the LD ring */
+		list_add_tail(&new->node, &first->tx_list);
+	} while (len);
+
+	new->tx.flags = flags; /* client is in control of this ack */
+	new->tx.cookie = -EBUSY;
+	list_splice(&first->tx_list, &new->tx_list);
+
+	return &new->tx;
+
+fail:
+	if (!first)
+		return NULL;
+
+	xgene_dma_free_tx_desc_list(chan, &first->tx_list);
+	return NULL;
+}
+
+static struct dma_async_tx_descriptor *xgene_dma_prep_sg(
+	struct dma_chan *dchan, struct scatterlist *dst_sg,
+	u32 dst_nents, struct scatterlist *src_sg,
+	u32 src_nents, unsigned long flags)
+{
+	struct xgene_dma_desc_sw *first = NULL, *new = NULL;
+	struct xgene_dma_chan *chan;
+	size_t dst_avail, src_avail;
+	dma_addr_t dst, src;
+	size_t len;
+
+	if (unlikely(!dchan))
+		return NULL;
+
+	if (unlikely(!dst_nents || !src_nents))
+		return NULL;
+
+	if (unlikely(!dst_sg || !src_sg))
+		return NULL;
+
+	chan = to_dma_chan(dchan);
+
+	/* Get prepared for the loop */
+	dst_avail = sg_dma_len(dst_sg);
+	src_avail = sg_dma_len(src_sg);
+	dst_nents--;
+	src_nents--;
+
+	/* Run until we are out of scatterlist entries */
+	while (true) {
+		/* Create the largest transaction possible */
+		len = min_t(size_t, src_avail, dst_avail);
+		len = min_t(size_t, len, XGENE_DMA_MAX_64B_DESC_BYTE_CNT);
+		if (len == 0)
+			goto fetch;
+
+		dst = sg_dma_address(dst_sg) + sg_dma_len(dst_sg) - dst_avail;
+		src = sg_dma_address(src_sg) + sg_dma_len(src_sg) - src_avail;
+
+		/* Allocate the link descriptor from DMA pool */
+		new = xgene_dma_alloc_descriptor(chan);
+		if (!new)
+			goto fail;
+
+		/* Prepare DMA descriptor */
+		xgene_dma_prep_cpy_desc(chan, new, dst, src, len);
+
+		if (!first)
+			first = new;
+
+		new->tx.cookie = 0;
+		async_tx_ack(&new->tx);
+
+		/* update metadata */
+		dst_avail -= len;
+		src_avail -= len;
+
+		/* Insert the link descriptor to the LD ring */
+		list_add_tail(&new->node, &first->tx_list);
+
+fetch:
+		/* fetch the next dst scatterlist entry */
+		if (dst_avail == 0) {
+			/* no more entries: we're done */
+			if (dst_nents == 0)
+				break;
+
+			/* fetch the next entry: if there are no more: done */
+			dst_sg = sg_next(dst_sg);
+			if (!dst_sg)
+				break;
+
+			dst_nents--;
+			dst_avail = sg_dma_len(dst_sg);
+		}
+
+		/* fetch the next src scatterlist entry */
+		if (src_avail == 0) {
+			/* no more entries: we're done */
+			if (src_nents == 0)
+				break;
+
+			/* fetch the next entry: if there are no more: done */
+			src_sg = sg_next(src_sg);
+			if (!src_sg)
+				break;
+
+			src_nents--;
+			src_avail = sg_dma_len(src_sg);
+		}
+	}
+
+	if (!new)
+		return NULL;
+
+	new->tx.flags = flags; /* client is in control of this ack */
+	new->tx.cookie = -EBUSY;
+	list_splice(&first->tx_list, &new->tx_list);
+
+	return &new->tx;
+fail:
+	if (!first)
+		return NULL;
+
+	xgene_dma_free_tx_desc_list(chan, &first->tx_list);
+	return NULL;
+}
+
+static struct dma_async_tx_descriptor *xgene_dma_prep_xor(
+	struct dma_chan *dchan, dma_addr_t dst,	dma_addr_t *src,
+	u32 src_cnt, size_t len, unsigned long flags)
+{
+	struct xgene_dma_desc_sw *first = NULL, *new;
+	struct xgene_dma_chan *chan;
+	static u8 multi[XGENE_DMA_MAX_XOR_SRC] = {
+				0x01, 0x01, 0x01, 0x01, 0x01};
+
+	if (unlikely(!dchan || !len))
+		return NULL;
+
+	chan = to_dma_chan(dchan);
+
+	do {
+		/* Allocate the link descriptor from DMA pool */
+		new = xgene_dma_alloc_descriptor(chan);
+		if (!new)
+			goto fail;
+
+		/* Prepare xor DMA descriptor */
+		xgene_dma_prep_xor_desc(chan, new, &dst, src,
+					src_cnt, &len, multi);
+
+		if (!first)
+			first = new;
+
+		new->tx.cookie = 0;
+		async_tx_ack(&new->tx);
+
+		/* Insert the link descriptor to the LD ring */
+		list_add_tail(&new->node, &first->tx_list);
+	} while (len);
+
+	new->tx.flags = flags; /* client is in control of this ack */
+	new->tx.cookie = -EBUSY;
+	list_splice(&first->tx_list, &new->tx_list);
+
+	return &new->tx;
+
+fail:
+	if (!first)
+		return NULL;
+
+	xgene_dma_free_tx_desc_list(chan, &first->tx_list);
+	return NULL;
+}
+
+static struct dma_async_tx_descriptor *xgene_dma_prep_pq(
+	struct dma_chan *dchan, dma_addr_t *dst, dma_addr_t *src,
+	u32 src_cnt, const u8 *scf, size_t len, unsigned long flags)
+{
+	struct xgene_dma_desc_sw *first = NULL, *new;
+	struct xgene_dma_chan *chan;
+	size_t _len = len;
+	dma_addr_t _src[XGENE_DMA_MAX_XOR_SRC];
+	static u8 multi[XGENE_DMA_MAX_XOR_SRC] = {0x01, 0x01, 0x01, 0x01, 0x01};
+
+	if (unlikely(!dchan || !len))
+		return NULL;
+
+	chan = to_dma_chan(dchan);
+
+	/*
+	 * Save source addresses on local variable, may be we have to
+	 * prepare two descriptor to generate P and Q if both enabled
+	 * in the flags by client
+	 */
+	memcpy(_src, src, sizeof(*src) * src_cnt);
+
+	if (flags & DMA_PREP_PQ_DISABLE_P)
+		len = 0;
+
+	if (flags & DMA_PREP_PQ_DISABLE_Q)
+		_len = 0;
+
+	do {
+		/* Allocate the link descriptor from DMA pool */
+		new = xgene_dma_alloc_descriptor(chan);
+		if (!new)
+			goto fail;
+
+		if (!first)
+			first = new;
+
+		new->tx.cookie = 0;
+		async_tx_ack(&new->tx);
+
+		/* Insert the link descriptor to the LD ring */
+		list_add_tail(&new->node, &first->tx_list);
+
+		/*
+		 * Prepare DMA descriptor to generate P,
+		 * if DMA_PREP_PQ_DISABLE_P flag is not set
+		 */
+		if (len) {
+			xgene_dma_prep_xor_desc(chan, new, &dst[0], src,
+						src_cnt, &len, multi);
+			continue;
+		}
+
+		/*
+		 * Prepare DMA descriptor to generate Q,
+		 * if DMA_PREP_PQ_DISABLE_Q flag is not set
+		 */
+		if (_len) {
+			xgene_dma_prep_xor_desc(chan, new, &dst[1], _src,
+						src_cnt, &_len, scf);
+		}
+	} while (len || _len);
+
+	new->tx.flags = flags; /* client is in control of this ack */
+	new->tx.cookie = -EBUSY;
+	list_splice(&first->tx_list, &new->tx_list);
+
+	return &new->tx;
+
+fail:
+	if (!first)
+		return NULL;
+
+	xgene_dma_free_tx_desc_list(chan, &first->tx_list);
+	return NULL;
+}
+
+static void xgene_dma_issue_pending(struct dma_chan *dchan)
+{
+	struct xgene_dma_chan *chan = to_dma_chan(dchan);
+
+	spin_lock_bh(&chan->lock);
+	xgene_chan_xfer_ld_pending(chan);
+	spin_unlock_bh(&chan->lock);
+}
+
+static enum dma_status xgene_dma_tx_status(struct dma_chan *dchan,
+					   dma_cookie_t cookie,
+					   struct dma_tx_state *txstate)
+{
+	return dma_cookie_status(dchan, cookie, txstate);
+}
+
+static void xgene_dma_tasklet_cb(unsigned long data)
+{
+	struct xgene_dma_chan *chan = (struct xgene_dma_chan *)data;
+
+	spin_lock_bh(&chan->lock);
+
+	/* Run all cleanup for descriptors which have been completed */
+	xgene_dma_cleanup_descriptors(chan);
+
+	/* Re-enable DMA channel IRQ */
+	enable_irq(chan->rx_irq);
+
+	spin_unlock_bh(&chan->lock);
+}
+
+static irqreturn_t xgene_dma_chan_ring_isr(int irq, void *id)
+{
+	struct xgene_dma_chan *chan = (struct xgene_dma_chan *)id;
+
+	BUG_ON(!chan);
+
+	/*
+	 * Disable DMA channel IRQ until we process completed
+	 * descriptors
+	 */
+	disable_irq_nosync(chan->rx_irq);
+
+	/*
+	 * Schedule the tasklet to handle all cleanup of the current
+	 * transaction. It will start a new transaction if there is
+	 * one pending.
+	 */
+	tasklet_schedule(&chan->tasklet);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t xgene_dma_err_isr(int irq, void *id)
+{
+	struct xgene_dma *pdma = (struct xgene_dma *)id;
+	unsigned long int_mask;
+	u32 val, i;
+
+	val = ioread32(pdma->csr_dma + XGENE_DMA_INT);
+
+	/* Clear DMA interrupts */
+	iowrite32(val, pdma->csr_dma + XGENE_DMA_INT);
+
+	/* Print DMA error info */
+	int_mask = val >> XGENE_DMA_INT_MASK_SHIFT;
+	for_each_set_bit(i, &int_mask, ARRAY_SIZE(xgene_dma_err))
+		dev_err(pdma->dev,
+			"Interrupt status 0x%08X %s\n", val, xgene_dma_err[i]);
+
+	return IRQ_HANDLED;
+}
+
+static void xgene_dma_wr_ring_state(struct xgene_dma_ring *ring)
+{
+	int i;
+
+	iowrite32(ring->num, ring->pdma->csr_ring + XGENE_DMA_RING_STATE);
+
+	for (i = 0; i < XGENE_DMA_RING_NUM_CONFIG; i++)
+		iowrite32(ring->state[i], ring->pdma->csr_ring +
+			  XGENE_DMA_RING_STATE_WR_BASE + (i * 4));
+}
+
+static void xgene_dma_clr_ring_state(struct xgene_dma_ring *ring)
+{
+	memset(ring->state, 0, sizeof(u32) * XGENE_DMA_RING_NUM_CONFIG);
+	xgene_dma_wr_ring_state(ring);
+}
+
+static void xgene_dma_setup_ring(struct xgene_dma_ring *ring)
+{
+	void *ring_cfg = ring->state;
+	u64 addr = ring->desc_paddr;
+	void *desc;
+	u32 i, val;
+
+	ring->slots = ring->size / XGENE_DMA_RING_WQ_DESC_SIZE;
+
+	/* Clear DMA ring state */
+	xgene_dma_clr_ring_state(ring);
+
+	/* Set DMA ring type */
+	XGENE_DMA_RING_TYPE_SET(ring_cfg, XGENE_DMA_RING_TYPE_REGULAR);
+
+	if (ring->owner == XGENE_DMA_RING_OWNER_DMA) {
+		/* Set recombination buffer and timeout */
+		XGENE_DMA_RING_RECOMBBUF_SET(ring_cfg);
+		XGENE_DMA_RING_RECOMTIMEOUTL_SET(ring_cfg);
+		XGENE_DMA_RING_RECOMTIMEOUTH_SET(ring_cfg);
+	}
+
+	/* Initialize DMA ring state */
+	XGENE_DMA_RING_SELTHRSH_SET(ring_cfg);
+	XGENE_DMA_RING_ACCEPTLERR_SET(ring_cfg);
+	XGENE_DMA_RING_COHERENT_SET(ring_cfg);
+	XGENE_DMA_RING_ADDRL_SET(ring_cfg, addr);
+	XGENE_DMA_RING_ADDRH_SET(ring_cfg, addr);
+	XGENE_DMA_RING_SIZE_SET(ring_cfg, ring->cfgsize);
+
+	/* Write DMA ring configurations */
+	xgene_dma_wr_ring_state(ring);
+
+	/* Set DMA ring id */
+	iowrite32(XGENE_DMA_RING_ID_SETUP(ring->id),
+		  ring->pdma->csr_ring + XGENE_DMA_RING_ID);
+
+	/* Set DMA ring buffer */
+	iowrite32(XGENE_DMA_RING_ID_BUF_SETUP(ring->num),
+		  ring->pdma->csr_ring + XGENE_DMA_RING_ID_BUF);
+
+	if (ring->owner != XGENE_DMA_RING_OWNER_CPU)
+		return;
+
+	/* Set empty signature to DMA Rx ring descriptors */
+	for (i = 0; i < ring->slots; i++) {
+		desc = &ring->desc_hw[i];
+		XGENE_DMA_DESC_SET_EMPTY(desc);
+	}
+
+	/* Enable DMA Rx ring interrupt */
+	val = ioread32(ring->pdma->csr_ring + XGENE_DMA_RING_NE_INT_MODE);
+	XGENE_DMA_RING_NE_INT_MODE_SET(val, ring->buf_num);
+	iowrite32(val, ring->pdma->csr_ring + XGENE_DMA_RING_NE_INT_MODE);
+}
+
+static void xgene_dma_clear_ring(struct xgene_dma_ring *ring)
+{
+	u32 ring_id, val;
+
+	if (ring->owner == XGENE_DMA_RING_OWNER_CPU) {
+		/* Disable DMA Rx ring interrupt */
+		val = ioread32(ring->pdma->csr_ring +
+			       XGENE_DMA_RING_NE_INT_MODE);
+		XGENE_DMA_RING_NE_INT_MODE_RESET(val, ring->buf_num);
+		iowrite32(val, ring->pdma->csr_ring +
+			  XGENE_DMA_RING_NE_INT_MODE);
+	}
+
+	/* Clear DMA ring state */
+	ring_id = XGENE_DMA_RING_ID_SETUP(ring->id);
+	iowrite32(ring_id, ring->pdma->csr_ring + XGENE_DMA_RING_ID);
+
+	iowrite32(0, ring->pdma->csr_ring + XGENE_DMA_RING_ID_BUF);
+	xgene_dma_clr_ring_state(ring);
+}
+
+static void xgene_dma_set_ring_cmd(struct xgene_dma_ring *ring)
+{
+	ring->cmd_base = ring->pdma->csr_ring_cmd +
+				XGENE_DMA_RING_CMD_BASE_OFFSET((ring->num -
+							  XGENE_DMA_RING_NUM));
+
+	ring->cmd = ring->cmd_base + XGENE_DMA_RING_CMD_OFFSET;
+}
+
+static int xgene_dma_get_ring_size(struct xgene_dma_chan *chan,
+				   enum xgene_dma_ring_cfgsize cfgsize)
+{
+	int size;
+
+	switch (cfgsize) {
+	case XGENE_DMA_RING_CFG_SIZE_512B:
+		size = 0x200;
+		break;
+	case XGENE_DMA_RING_CFG_SIZE_2KB:
+		size = 0x800;
+		break;
+	case XGENE_DMA_RING_CFG_SIZE_16KB:
+		size = 0x4000;
+		break;
+	case XGENE_DMA_RING_CFG_SIZE_64KB:
+		size = 0x10000;
+		break;
+	case XGENE_DMA_RING_CFG_SIZE_512KB:
+		size = 0x80000;
+		break;
+	default:
+		chan_err(chan, "Unsupported cfg ring size %d\n", cfgsize);
+		return -EINVAL;
+	}
+
+	return size;
+}
+
+static void xgene_dma_delete_ring_one(struct xgene_dma_ring *ring)
+{
+	/* Clear DMA ring configurations */
+	xgene_dma_clear_ring(ring);
+
+	/* De-allocate DMA ring descriptor */
+	if (ring->desc_vaddr) {
+		dma_free_coherent(ring->pdma->dev, ring->size,
+				  ring->desc_vaddr, ring->desc_paddr);
+		ring->desc_vaddr = NULL;
+	}
+}
+
+static void xgene_dma_delete_chan_rings(struct xgene_dma_chan *chan)
+{
+	xgene_dma_delete_ring_one(&chan->rx_ring);
+	xgene_dma_delete_ring_one(&chan->tx_ring);
+}
+
+static int xgene_dma_create_ring_one(struct xgene_dma_chan *chan,
+				     struct xgene_dma_ring *ring,
+				     enum xgene_dma_ring_cfgsize cfgsize)
+{
+	/* Setup DMA ring descriptor variables */
+	ring->pdma = chan->pdma;
+	ring->cfgsize = cfgsize;
+	ring->num = chan->pdma->ring_num++;
+	ring->id = XGENE_DMA_RING_ID_GET(ring->owner, ring->buf_num);
+
+	ring->size = xgene_dma_get_ring_size(chan, cfgsize);
+	if (ring->size <= 0)
+		return ring->size;
+
+	/* Allocate memory for DMA ring descriptor */
+	ring->desc_vaddr = dma_zalloc_coherent(chan->dev, ring->size,
+					       &ring->desc_paddr, GFP_KERNEL);
+	if (!ring->desc_vaddr) {
+		chan_err(chan, "Failed to allocate ring desc\n");
+		return -ENOMEM;
+	}
+
+	/* Configure and enable DMA ring */
+	xgene_dma_set_ring_cmd(ring);
+	xgene_dma_setup_ring(ring);
+
+	return 0;
+}
+
+static int xgene_dma_create_chan_rings(struct xgene_dma_chan *chan)
+{
+	struct xgene_dma_ring *rx_ring = &chan->rx_ring;
+	struct xgene_dma_ring *tx_ring = &chan->tx_ring;
+	int ret;
+
+	/* Create DMA Rx ring descriptor */
+	rx_ring->owner = XGENE_DMA_RING_OWNER_CPU;
+	rx_ring->buf_num = XGENE_DMA_CPU_BUFNUM + chan->id;
+
+	ret = xgene_dma_create_ring_one(chan, rx_ring,
+					XGENE_DMA_RING_CFG_SIZE_64KB);
+	if (ret)
+		return ret;
+
+	chan_dbg(chan, "Rx ring id 0x%X num %d desc 0x%p\n",
+		 rx_ring->id, rx_ring->num, rx_ring->desc_vaddr);
+
+	/* Create DMA Tx ring descriptor */
+	tx_ring->owner = XGENE_DMA_RING_OWNER_DMA;
+	tx_ring->buf_num = XGENE_DMA_BUFNUM + chan->id;
+
+	ret = xgene_dma_create_ring_one(chan, tx_ring,
+					XGENE_DMA_RING_CFG_SIZE_64KB);
+	if (ret) {
+		xgene_dma_delete_ring_one(rx_ring);
+		return ret;
+	}
+
+	tx_ring->dst_ring_num = XGENE_DMA_RING_DST_ID(rx_ring->num);
+
+	chan_dbg(chan,
+		 "Tx ring id 0x%X num %d desc 0x%p\n",
+		 tx_ring->id, tx_ring->num, tx_ring->desc_vaddr);
+
+	/* Set the max outstanding request possible to this channel */
+	chan->max_outstanding = rx_ring->slots;
+
+	return ret;
+}
+
+static int xgene_dma_init_rings(struct xgene_dma *pdma)
+{
+	int ret, i, j;
+
+	for (i = 0; i < XGENE_DMA_MAX_CHANNEL; i++) {
+		ret = xgene_dma_create_chan_rings(&pdma->chan[i]);
+		if (ret) {
+			for (j = 0; j < i; j++)
+				xgene_dma_delete_chan_rings(&pdma->chan[j]);
+			return ret;
+		}
+	}
+
+	return ret;
+}
+
+static void xgene_dma_enable(struct xgene_dma *pdma)
+{
+	u32 val;
+
+	/* Configure and enable DMA engine */
+	val = ioread32(pdma->csr_dma + XGENE_DMA_GCR);
+	XGENE_DMA_CH_SETUP(val);
+	XGENE_DMA_ENABLE(val);
+	iowrite32(val, pdma->csr_dma + XGENE_DMA_GCR);
+}
+
+static void xgene_dma_disable(struct xgene_dma *pdma)
+{
+	u32 val;
+
+	val = ioread32(pdma->csr_dma + XGENE_DMA_GCR);
+	XGENE_DMA_DISABLE(val);
+	iowrite32(val, pdma->csr_dma + XGENE_DMA_GCR);
+}
+
+static void xgene_dma_mask_interrupts(struct xgene_dma *pdma)
+{
+	/*
+	 * Mask DMA ring overflow, underflow and
+	 * AXI write/read error interrupts
+	 */
+	iowrite32(XGENE_DMA_INT_ALL_MASK,
+		  pdma->csr_dma + XGENE_DMA_RING_INT0_MASK);
+	iowrite32(XGENE_DMA_INT_ALL_MASK,
+		  pdma->csr_dma + XGENE_DMA_RING_INT1_MASK);
+	iowrite32(XGENE_DMA_INT_ALL_MASK,
+		  pdma->csr_dma + XGENE_DMA_RING_INT2_MASK);
+	iowrite32(XGENE_DMA_INT_ALL_MASK,
+		  pdma->csr_dma + XGENE_DMA_RING_INT3_MASK);
+	iowrite32(XGENE_DMA_INT_ALL_MASK,
+		  pdma->csr_dma + XGENE_DMA_RING_INT4_MASK);
+
+	/* Mask DMA error interrupts */
+	iowrite32(XGENE_DMA_INT_ALL_MASK, pdma->csr_dma + XGENE_DMA_INT_MASK);
+}
+
+static void xgene_dma_unmask_interrupts(struct xgene_dma *pdma)
+{
+	/*
+	 * Unmask DMA ring overflow, underflow and
+	 * AXI write/read error interrupts
+	 */
+	iowrite32(XGENE_DMA_INT_ALL_UNMASK,
+		  pdma->csr_dma + XGENE_DMA_RING_INT0_MASK);
+	iowrite32(XGENE_DMA_INT_ALL_UNMASK,
+		  pdma->csr_dma + XGENE_DMA_RING_INT1_MASK);
+	iowrite32(XGENE_DMA_INT_ALL_UNMASK,
+		  pdma->csr_dma + XGENE_DMA_RING_INT2_MASK);
+	iowrite32(XGENE_DMA_INT_ALL_UNMASK,
+		  pdma->csr_dma + XGENE_DMA_RING_INT3_MASK);
+	iowrite32(XGENE_DMA_INT_ALL_UNMASK,
+		  pdma->csr_dma + XGENE_DMA_RING_INT4_MASK);
+
+	/* Unmask DMA error interrupts */
+	iowrite32(XGENE_DMA_INT_ALL_UNMASK,
+		  pdma->csr_dma + XGENE_DMA_INT_MASK);
+}
+
+static void xgene_dma_init_hw(struct xgene_dma *pdma)
+{
+	u32 val;
+
+	/* Associate DMA ring to corresponding ring HW */
+	iowrite32(XGENE_DMA_ASSOC_RING_MNGR1,
+		  pdma->csr_dma + XGENE_DMA_CFG_RING_WQ_ASSOC);
+
+	/* Configure RAID6 polynomial control setting */
+	if (is_pq_enabled(pdma))
+		iowrite32(XGENE_DMA_RAID6_MULTI_CTRL(0x1D),
+			  pdma->csr_dma + XGENE_DMA_RAID6_CONT);
+	else
+		dev_info(pdma->dev, "PQ is disabled in HW\n");
+
+	xgene_dma_enable(pdma);
+	xgene_dma_unmask_interrupts(pdma);
+
+	/* Get DMA id and version info */
+	val = ioread32(pdma->csr_dma + XGENE_DMA_IPBRR);
+
+	/* DMA device info */
+	dev_info(pdma->dev,
+		 "X-Gene DMA v%d.%02d.%02d driver registered %d channels",
+		 XGENE_DMA_REV_NO_RD(val), XGENE_DMA_BUS_ID_RD(val),
+		 XGENE_DMA_DEV_ID_RD(val), XGENE_DMA_MAX_CHANNEL);
+}
+
+int xgene_dma_init_ring_mngr(struct xgene_dma *pdma)
+{
+	if (ioread32(pdma->csr_ring + XGENE_DMA_RING_CLKEN) &&
+	    (!ioread32(pdma->csr_ring + XGENE_DMA_RING_SRST)))
+		return 0;
+
+	iowrite32(0x3, pdma->csr_ring + XGENE_DMA_RING_CLKEN);
+	iowrite32(0x0, pdma->csr_ring + XGENE_DMA_RING_SRST);
+
+	/* Bring up memory */
+	iowrite32(0x0, pdma->csr_ring + XGENE_DMA_RING_MEM_RAM_SHUTDOWN);
+
+	/* Force a barrier */
+	ioread32(pdma->csr_ring + XGENE_DMA_RING_MEM_RAM_SHUTDOWN);
+
+	/* reset may take up to 1ms */
+	usleep_range(1000, 1100);
+
+	if (ioread32(pdma->csr_ring + XGENE_DMA_RING_BLK_MEM_RDY)
+		!= XGENE_DMA_RING_BLK_MEM_RDY_VAL) {
+		dev_err(pdma->dev,
+			"Failed to release ring mngr memory from shutdown\n");
+		return -ENODEV;
+	}
+
+	/* program threshold set 1 and all hysteresis */
+	iowrite32(XGENE_DMA_RING_THRESLD0_SET1_VAL,
+		  pdma->csr_ring + XGENE_DMA_RING_THRESLD0_SET1);
+	iowrite32(XGENE_DMA_RING_THRESLD1_SET1_VAL,
+		  pdma->csr_ring + XGENE_DMA_RING_THRESLD1_SET1);
+	iowrite32(XGENE_DMA_RING_HYSTERESIS_VAL,
+		  pdma->csr_ring + XGENE_DMA_RING_HYSTERESIS);
+
+	/* Enable QPcore and assign error queue */
+	iowrite32(XGENE_DMA_RING_ENABLE,
+		  pdma->csr_ring + XGENE_DMA_RING_CONFIG);
+
+	return 0;
+}
+
+static int xgene_dma_init_mem(struct xgene_dma *pdma)
+{
+	int ret;
+
+	ret = xgene_dma_init_ring_mngr(pdma);
+	if (ret)
+		return ret;
+
+	/* Bring up memory */
+	iowrite32(0x0, pdma->csr_dma + XGENE_DMA_MEM_RAM_SHUTDOWN);
+
+	/* Force a barrier */
+	ioread32(pdma->csr_dma + XGENE_DMA_MEM_RAM_SHUTDOWN);
+
+	/* reset may take up to 1ms */
+	usleep_range(1000, 1100);
+
+	if (ioread32(pdma->csr_dma + XGENE_DMA_BLK_MEM_RDY)
+		!= XGENE_DMA_BLK_MEM_RDY_VAL) {
+		dev_err(pdma->dev,
+			"Failed to release DMA memory from shutdown\n");
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
+static int xgene_dma_request_irqs(struct xgene_dma *pdma)
+{
+	struct xgene_dma_chan *chan;
+	int ret, i, j;
+
+	/* Register DMA error irq */
+	ret = devm_request_irq(pdma->dev, pdma->err_irq, xgene_dma_err_isr,
+			       0, "dma_error", pdma);
+	if (ret) {
+		dev_err(pdma->dev,
+			"Failed to register error IRQ %d\n", pdma->err_irq);
+		return ret;
+	}
+
+	/* Register DMA channel rx irq */
+	for (i = 0; i < XGENE_DMA_MAX_CHANNEL; i++) {
+		chan = &pdma->chan[i];
+		ret = devm_request_irq(chan->dev, chan->rx_irq,
+				       xgene_dma_chan_ring_isr,
+				       0, chan->name, chan);
+		if (ret) {
+			chan_err(chan, "Failed to register Rx IRQ %d\n",
+				 chan->rx_irq);
+			devm_free_irq(pdma->dev, pdma->err_irq, pdma);
+
+			for (j = 0; j < i; j++) {
+				chan = &pdma->chan[i];
+				devm_free_irq(chan->dev, chan->rx_irq, chan);
+			}
+
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+static void xgene_dma_free_irqs(struct xgene_dma *pdma)
+{
+	struct xgene_dma_chan *chan;
+	int i;
+
+	/* Free DMA device error irq */
+	devm_free_irq(pdma->dev, pdma->err_irq, pdma);
+
+	for (i = 0; i < XGENE_DMA_MAX_CHANNEL; i++) {
+		chan = &pdma->chan[i];
+		devm_free_irq(chan->dev, chan->rx_irq, chan);
+	}
+}
+
+static void xgene_dma_set_caps(struct xgene_dma_chan *chan,
+			       struct dma_device *dma_dev)
+{
+	/* Initialize DMA device capability mask */
+	dma_cap_zero(dma_dev->cap_mask);
+
+	/* Set DMA device capability */
+	dma_cap_set(DMA_MEMCPY, dma_dev->cap_mask);
+	dma_cap_set(DMA_SG, dma_dev->cap_mask);
+
+	/* Basically here, the X-Gene SoC DMA engine channel 0 supports XOR
+	 * and channel 1 supports XOR, PQ both. First thing here is we have
+	 * mechanism in hw to enable/disable PQ/XOR supports on channel 1,
+	 * we can make sure this by reading SoC Efuse register.
+	 * Second thing, we have hw errata that if we run channel 0 and
+	 * channel 1 simultaneously with executing XOR and PQ request,
+	 * suddenly DMA engine hangs, So here we enable XOR on channel 0 only
+	 * if XOR and PQ supports on channel 1 is disabled.
+	 */
+	if ((chan->id == XGENE_DMA_PQ_CHANNEL) &&
+	    is_pq_enabled(chan->pdma)) {
+		dma_cap_set(DMA_PQ, dma_dev->cap_mask);
+		dma_cap_set(DMA_XOR, dma_dev->cap_mask);
+	} else if ((chan->id == XGENE_DMA_XOR_CHANNEL) &&
+		   !is_pq_enabled(chan->pdma)) {
+		dma_cap_set(DMA_XOR, dma_dev->cap_mask);
+	}
+
+	/* Set base and prep routines */
+	dma_dev->dev = chan->dev;
+	dma_dev->device_alloc_chan_resources = xgene_dma_alloc_chan_resources;
+	dma_dev->device_free_chan_resources = xgene_dma_free_chan_resources;
+	dma_dev->device_issue_pending = xgene_dma_issue_pending;
+	dma_dev->device_tx_status = xgene_dma_tx_status;
+	dma_dev->device_prep_dma_memcpy = xgene_dma_prep_memcpy;
+	dma_dev->device_prep_dma_sg = xgene_dma_prep_sg;
+
+	if (dma_has_cap(DMA_XOR, dma_dev->cap_mask)) {
+		dma_dev->device_prep_dma_xor = xgene_dma_prep_xor;
+		dma_dev->max_xor = XGENE_DMA_MAX_XOR_SRC;
+		dma_dev->xor_align = XGENE_DMA_XOR_ALIGNMENT;
+	}
+
+	if (dma_has_cap(DMA_PQ, dma_dev->cap_mask)) {
+		dma_dev->device_prep_dma_pq = xgene_dma_prep_pq;
+		dma_dev->max_pq = XGENE_DMA_MAX_XOR_SRC;
+		dma_dev->pq_align = XGENE_DMA_XOR_ALIGNMENT;
+	}
+}
+
+static int xgene_dma_async_register(struct xgene_dma *pdma, int id)
+{
+	struct xgene_dma_chan *chan = &pdma->chan[id];
+	struct dma_device *dma_dev = &pdma->dma_dev[id];
+	int ret;
+
+	chan->dma_chan.device = dma_dev;
+
+	spin_lock_init(&chan->lock);
+	INIT_LIST_HEAD(&chan->ld_pending);
+	INIT_LIST_HEAD(&chan->ld_running);
+	INIT_LIST_HEAD(&chan->ld_completed);
+	tasklet_init(&chan->tasklet, xgene_dma_tasklet_cb,
+		     (unsigned long)chan);
+
+	chan->pending = 0;
+	chan->desc_pool = NULL;
+	dma_cookie_init(&chan->dma_chan);
+
+	/* Setup dma device capabilities and prep routines */
+	xgene_dma_set_caps(chan, dma_dev);
+
+	/* Initialize DMA device list head */
+	INIT_LIST_HEAD(&dma_dev->channels);
+	list_add_tail(&chan->dma_chan.device_node, &dma_dev->channels);
+
+	/* Register with Linux async DMA framework*/
+	ret = dma_async_device_register(dma_dev);
+	if (ret) {
+		chan_err(chan, "Failed to register async device %d", ret);
+		tasklet_kill(&chan->tasklet);
+
+		return ret;
+	}
+
+	/* DMA capability info */
+	dev_info(pdma->dev,
+		 "%s: CAPABILITY ( %s%s%s%s)\n", dma_chan_name(&chan->dma_chan),
+		 dma_has_cap(DMA_MEMCPY, dma_dev->cap_mask) ? "MEMCPY " : "",
+		 dma_has_cap(DMA_SG, dma_dev->cap_mask) ? "SGCPY " : "",
+		 dma_has_cap(DMA_XOR, dma_dev->cap_mask) ? "XOR " : "",
+		 dma_has_cap(DMA_PQ, dma_dev->cap_mask) ? "PQ " : "");
+
+	return 0;
+}
+
+static int xgene_dma_init_async(struct xgene_dma *pdma)
+{
+	int ret, i, j;
+
+	for (i = 0; i < XGENE_DMA_MAX_CHANNEL ; i++) {
+		ret = xgene_dma_async_register(pdma, i);
+		if (ret) {
+			for (j = 0; j < i; j++) {
+				dma_async_device_unregister(&pdma->dma_dev[j]);
+				tasklet_kill(&pdma->chan[j].tasklet);
+			}
+
+			return ret;
+		}
+	}
+
+	return ret;
+}
+
+static void xgene_dma_async_unregister(struct xgene_dma *pdma)
+{
+	int i;
+
+	for (i = 0; i < XGENE_DMA_MAX_CHANNEL; i++)
+		dma_async_device_unregister(&pdma->dma_dev[i]);
+}
+
+static void xgene_dma_init_channels(struct xgene_dma *pdma)
+{
+	struct xgene_dma_chan *chan;
+	int i;
+
+	pdma->ring_num = XGENE_DMA_RING_NUM;
+
+	for (i = 0; i < XGENE_DMA_MAX_CHANNEL; i++) {
+		chan = &pdma->chan[i];
+		chan->dev = pdma->dev;
+		chan->pdma = pdma;
+		chan->id = i;
+		sprintf(chan->name, "dmachan%d", chan->id);
+	}
+}
+
+static int xgene_dma_get_resources(struct platform_device *pdev,
+				   struct xgene_dma *pdma)
+{
+	struct resource *res;
+	int irq, i;
+
+	/* Get DMA csr region */
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(&pdev->dev, "Failed to get csr region\n");
+		return -ENXIO;
+	}
+
+	pdma->csr_dma = devm_ioremap(&pdev->dev, res->start,
+				     resource_size(res));
+	if (IS_ERR(pdma->csr_dma)) {
+		dev_err(&pdev->dev, "Failed to ioremap csr region");
+		return PTR_ERR(pdma->csr_dma);
+	}
+
+	/* Get DMA ring csr region */
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+	if (!res) {
+		dev_err(&pdev->dev, "Failed to get ring csr region\n");
+		return -ENXIO;
+	}
+
+	pdma->csr_ring =  devm_ioremap(&pdev->dev, res->start,
+				       resource_size(res));
+	if (IS_ERR(pdma->csr_ring)) {
+		dev_err(&pdev->dev, "Failed to ioremap ring csr region");
+		return PTR_ERR(pdma->csr_ring);
+	}
+
+	/* Get DMA ring cmd csr region */
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 2);
+	if (!res) {
+		dev_err(&pdev->dev, "Failed to get ring cmd csr region\n");
+		return -ENXIO;
+	}
+
+	pdma->csr_ring_cmd = devm_ioremap(&pdev->dev, res->start,
+					  resource_size(res));
+	if (IS_ERR(pdma->csr_ring_cmd)) {
+		dev_err(&pdev->dev, "Failed to ioremap ring cmd csr region");
+		return PTR_ERR(pdma->csr_ring_cmd);
+	}
+
+	/* Get efuse csr region */
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 3);
+	if (!res) {
+		dev_err(&pdev->dev, "Failed to get efuse csr region\n");
+		return -ENXIO;
+	}
+
+	pdma->csr_efuse = devm_ioremap(&pdev->dev, res->start,
+				       resource_size(res));
+	if (IS_ERR(pdma->csr_efuse)) {
+		dev_err(&pdev->dev, "Failed to ioremap efuse csr region");
+		return PTR_ERR(pdma->csr_efuse);
+	}
+
+	/* Get DMA error interrupt */
+	irq = platform_get_irq(pdev, 0);
+	if (irq <= 0) {
+		dev_err(&pdev->dev, "Failed to get Error IRQ\n");
+		return -ENXIO;
+	}
+
+	pdma->err_irq = irq;
+
+	/* Get DMA Rx ring descriptor interrupts for all DMA channels */
+	for (i = 1; i <= XGENE_DMA_MAX_CHANNEL; i++) {
+		irq = platform_get_irq(pdev, i);
+		if (irq <= 0) {
+			dev_err(&pdev->dev, "Failed to get Rx IRQ\n");
+			return -ENXIO;
+		}
+
+		pdma->chan[i - 1].rx_irq = irq;
+	}
+
+	return 0;
+}
+
+static int xgene_dma_probe(struct platform_device *pdev)
+{
+	struct xgene_dma *pdma;
+	int ret, i;
+
+	pdma = devm_kzalloc(&pdev->dev, sizeof(*pdma), GFP_KERNEL);
+	if (!pdma)
+		return -ENOMEM;
+
+	pdma->dev = &pdev->dev;
+	platform_set_drvdata(pdev, pdma);
+
+	ret = xgene_dma_get_resources(pdev, pdma);
+	if (ret)
+		return ret;
+
+	pdma->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(pdma->clk)) {
+		dev_err(&pdev->dev, "Failed to get clk\n");
+		return PTR_ERR(pdma->clk);
+	}
+
+	/* Enable clk before accessing registers */
+	ret = clk_prepare_enable(pdma->clk);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to enable clk %d\n", ret);
+		return ret;
+	}
+
+	/* Remove DMA RAM out of shutdown */
+	ret = xgene_dma_init_mem(pdma);
+	if (ret)
+		goto err_clk_enable;
+
+	ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(42));
+	if (ret) {
+		dev_err(&pdev->dev, "No usable DMA configuration\n");
+		goto err_dma_mask;
+	}
+
+	/* Initialize DMA channels software state */
+	xgene_dma_init_channels(pdma);
+
+	/* Configue DMA rings */
+	ret = xgene_dma_init_rings(pdma);
+	if (ret)
+		goto err_clk_enable;
+
+	ret = xgene_dma_request_irqs(pdma);
+	if (ret)
+		goto err_request_irq;
+
+	/* Configure and enable DMA engine */
+	xgene_dma_init_hw(pdma);
+
+	/* Register DMA device with linux async framework */
+	ret = xgene_dma_init_async(pdma);
+	if (ret)
+		goto err_async_init;
+
+	return 0;
+
+err_async_init:
+	xgene_dma_free_irqs(pdma);
+
+err_request_irq:
+	for (i = 0; i < XGENE_DMA_MAX_CHANNEL; i++)
+		xgene_dma_delete_chan_rings(&pdma->chan[i]);
+
+err_dma_mask:
+err_clk_enable:
+	clk_disable_unprepare(pdma->clk);
+
+	return ret;
+}
+
+static int xgene_dma_remove(struct platform_device *pdev)
+{
+	struct xgene_dma *pdma = platform_get_drvdata(pdev);
+	struct xgene_dma_chan *chan;
+	int i;
+
+	xgene_dma_async_unregister(pdma);
+
+	/* Mask interrupts and disable DMA engine */
+	xgene_dma_mask_interrupts(pdma);
+	xgene_dma_disable(pdma);
+	xgene_dma_free_irqs(pdma);
+
+	for (i = 0; i < XGENE_DMA_MAX_CHANNEL; i++) {
+		chan = &pdma->chan[i];
+		tasklet_kill(&chan->tasklet);
+		xgene_dma_delete_chan_rings(chan);
+	}
+
+	clk_disable_unprepare(pdma->clk);
+
+	return 0;
+}
+
+static const struct of_device_id xgene_dma_of_match_ptr[] = {
+	{.compatible = "apm,xgene-storm-dma",},
+	{},
+};
+MODULE_DEVICE_TABLE(of, xgene_dma_of_match_ptr);
+
+static struct platform_driver xgene_dma_driver = {
+	.probe = xgene_dma_probe,
+	.remove = xgene_dma_remove,
+	.driver = {
+		.name = "X-Gene-DMA",
+		.owner = THIS_MODULE,
+		.of_match_table = xgene_dma_of_match_ptr,
+	},
+};
+
+module_platform_driver(xgene_dma_driver);
+
+MODULE_DESCRIPTION("APM X-Gene SoC DMA driver");
+MODULE_AUTHOR("Rameshwar Prasad Sahu <[e-mail]>");
+MODULE_AUTHOR("Loc Ho <[e-mail]>");
+MODULE_LICENSE("GPL");
+MODULE_VERSION("1.0");