diff mbox

[V6,2/3] dma-mapping: Rework dma_get_cache_alignment() function

Message ID 1505811161-25246-2-git-send-email-chenhc@lemote.com (mailing list archive)
State Changes Requested
Headers show

Commit Message

Huacai Chen Sept. 19, 2017, 8:52 a.m. UTC
Make dma_get_cache_alignment() to accept a 'dev' argument. As a result,
it can return different alignments due to different devices' I/O cache
coherency. For compatibility, make all existing callers pass a NULL dev
argument.

Cc: stable@vger.kernel.org
Signed-off-by: Huacai Chen <chenhc@lemote.com>
---
 drivers/infiniband/hw/mthca/mthca_main.c       |  2 +-
 drivers/media/v4l2-core/videobuf2-dma-contig.c |  2 +-
 drivers/net/ethernet/broadcom/b44.c            |  2 +-
 drivers/net/ethernet/ibm/emac/core.h           |  2 +-
 drivers/net/ethernet/mellanox/mlx4/main.c      |  2 +-
 drivers/spi/spi-qup.c                          |  4 ++--
 drivers/tty/serial/mpsc.c                      | 16 ++++++++--------
 drivers/tty/serial/samsung.c                   | 14 +++++++-------
 include/linux/dma-mapping.h                    | 14 +++++++++-----
 9 files changed, 31 insertions(+), 27 deletions(-)

Comments

Christoph Hellwig Sept. 19, 2017, 3:02 p.m. UTC | #1
>  	mdev->limits.reserved_mtts = ALIGN(mdev->limits.reserved_mtts * mdev->limits.mtt_seg_size,
> -					   dma_get_cache_alignment()) / mdev->limits.mtt_seg_size;
> +					   dma_get_cache_alignment(NULL)) / mdev->limits.mtt_seg_size;
>  
>  	mdev->mr_table.mtt_table = mthca_alloc_icm_table(mdev, init_hca->mtt_base,

Please pass the actually relevant struct device for each call.
Huacai Chen Sept. 21, 2017, 4:28 a.m. UTC | #2
Hi, Christoph,

I have changed dma_get_cache_alignment's return value, and I don't know whether those drivers want to return ARCH_DMA_MINALIGN unconditionally. So I pass a NULL for those drivers, in order to keep their old behavior.
 
Huacai
 
------------------ Original ------------------
From:  "Christoph Hellwig"<hch@lst.de>;

Date:  Tue, Sep 19, 2017 11:02 PM
To:  "Huacai Chen"<chenhc@lemote.com>; 
Cc:  "Christoph Hellwig"<hch@lst.de>; "Marek Szyprowski"<m.szyprowski@samsung.com>; "Robin Murphy"<robin.murphy@arm.com>; "Andrew Morton"<akpm@linux-foundation.org>; "Fuxin Zhang"<zhangfx@lemote.com>; "linux-kernel"<linux-kernel@vger.kernel.org>; "James E . J . Bottomley"<jejb@linux.vnet.ibm.com>; "Martin K . Petersen"<martin.petersen@oracle.com>; "linux-scsi"<linux-scsi@vger.kernel.org>; "stable"<stable@vger.kernel.org>; 
Subject:  Re: [PATCH V6 2/3] dma-mapping: Rework dma_get_cache_alignment()function

 
>  	mdev->limits.reserved_mtts = ALIGN(mdev->limits.reserved_mtts * mdev->limits.mtt_seg_size,

> -					   dma_get_cache_alignment()) / mdev->limits.mtt_seg_size;

> +					   dma_get_cache_alignment(NULL)) / mdev->limits.mtt_seg_size;

>  

>  	mdev->mr_table.mtt_table = mthca_alloc_icm_table(mdev, init_hca->mtt_base,


Please pass the actually relevant struct device for each call.
Christoph Hellwig Sept. 21, 2017, 2:36 p.m. UTC | #3
On Thu, Sep 21, 2017 at 12:28:25PM +0800, 陈华才 wrote:
> Hi, Christoph,
> 
> I have changed dma_get_cache_alignment's return value, and I don't know whether those drivers want to return ARCH_DMA_MINALIGN unconditionally. So I pass a NULL for those drivers, in order to keep their old behavior.

Per our documentation yes, they do want ARCH_DMA_MINALIGN.  Please
Cc all the driver maintainers on your updated patch so that they can
review it, though.
diff mbox

Patch

diff --git a/drivers/infiniband/hw/mthca/mthca_main.c b/drivers/infiniband/hw/mthca/mthca_main.c
index e36a9bc..cac5fac 100644
--- a/drivers/infiniband/hw/mthca/mthca_main.c
+++ b/drivers/infiniband/hw/mthca/mthca_main.c
@@ -416,7 +416,7 @@  static int mthca_init_icm(struct mthca_dev *mdev,
 
 	/* CPU writes to non-reserved MTTs, while HCA might DMA to reserved mtts */
 	mdev->limits.reserved_mtts = ALIGN(mdev->limits.reserved_mtts * mdev->limits.mtt_seg_size,
-					   dma_get_cache_alignment()) / mdev->limits.mtt_seg_size;
+					   dma_get_cache_alignment(NULL)) / mdev->limits.mtt_seg_size;
 
 	mdev->mr_table.mtt_table = mthca_alloc_icm_table(mdev, init_hca->mtt_base,
 							 mdev->limits.mtt_seg_size,
diff --git a/drivers/media/v4l2-core/videobuf2-dma-contig.c b/drivers/media/v4l2-core/videobuf2-dma-contig.c
index 9f389f3..7f54739 100644
--- a/drivers/media/v4l2-core/videobuf2-dma-contig.c
+++ b/drivers/media/v4l2-core/videobuf2-dma-contig.c
@@ -484,7 +484,7 @@  static void *vb2_dc_get_userptr(struct device *dev, unsigned long vaddr,
 	int ret = 0;
 	struct sg_table *sgt;
 	unsigned long contig_size;
-	unsigned long dma_align = dma_get_cache_alignment();
+	unsigned long dma_align = dma_get_cache_alignment(NULL);
 
 	/* Only cache aligned DMA transfers are reliable */
 	if (!IS_ALIGNED(vaddr | size, dma_align)) {
diff --git a/drivers/net/ethernet/broadcom/b44.c b/drivers/net/ethernet/broadcom/b44.c
index a1125d1..291d6af 100644
--- a/drivers/net/ethernet/broadcom/b44.c
+++ b/drivers/net/ethernet/broadcom/b44.c
@@ -2587,7 +2587,7 @@  static inline void b44_pci_exit(void)
 
 static int __init b44_init(void)
 {
-	unsigned int dma_desc_align_size = dma_get_cache_alignment();
+	unsigned int dma_desc_align_size = dma_get_cache_alignment(NULL);
 	int err;
 
 	/* Setup paramaters for syncing RX/TX DMA descriptors */
diff --git a/drivers/net/ethernet/ibm/emac/core.h b/drivers/net/ethernet/ibm/emac/core.h
index 369de2c..236bf37 100644
--- a/drivers/net/ethernet/ibm/emac/core.h
+++ b/drivers/net/ethernet/ibm/emac/core.h
@@ -68,7 +68,7 @@  static inline int emac_rx_size(int mtu)
 		return mal_rx_size(ETH_DATA_LEN + EMAC_MTU_OVERHEAD);
 }
 
-#define EMAC_DMA_ALIGN(x)		ALIGN((x), dma_get_cache_alignment())
+#define EMAC_DMA_ALIGN(x)		ALIGN((x), dma_get_cache_alignment(NULL))
 
 #define EMAC_RX_SKB_HEADROOM		\
 	EMAC_DMA_ALIGN(CONFIG_IBM_EMAC_RX_SKB_HEADROOM)
diff --git a/drivers/net/ethernet/mellanox/mlx4/main.c b/drivers/net/ethernet/mellanox/mlx4/main.c
index e61c99e..56b1449 100644
--- a/drivers/net/ethernet/mellanox/mlx4/main.c
+++ b/drivers/net/ethernet/mellanox/mlx4/main.c
@@ -1660,7 +1660,7 @@  static int mlx4_init_icm(struct mlx4_dev *dev, struct mlx4_dev_cap *dev_cap,
 	 */
 	dev->caps.reserved_mtts =
 		ALIGN(dev->caps.reserved_mtts * dev->caps.mtt_entry_sz,
-		      dma_get_cache_alignment()) / dev->caps.mtt_entry_sz;
+		      dma_get_cache_alignment(NULL)) / dev->caps.mtt_entry_sz;
 
 	err = mlx4_init_icm_table(dev, &priv->mr_table.mtt_table,
 				  init_hca->mtt_base,
diff --git a/drivers/spi/spi-qup.c b/drivers/spi/spi-qup.c
index 974a8ce..0c698c3 100644
--- a/drivers/spi/spi-qup.c
+++ b/drivers/spi/spi-qup.c
@@ -862,7 +862,7 @@  static bool spi_qup_can_dma(struct spi_master *master, struct spi_device *spi,
 			    struct spi_transfer *xfer)
 {
 	struct spi_qup *qup = spi_master_get_devdata(master);
-	size_t dma_align = dma_get_cache_alignment();
+	size_t dma_align = dma_get_cache_alignment(NULL);
 	int n_words;
 
 	if (xfer->rx_buf) {
@@ -1038,7 +1038,7 @@  static int spi_qup_probe(struct platform_device *pdev)
 	master->transfer_one = spi_qup_transfer_one;
 	master->dev.of_node = pdev->dev.of_node;
 	master->auto_runtime_pm = true;
-	master->dma_alignment = dma_get_cache_alignment();
+	master->dma_alignment = dma_get_cache_alignment(NULL);
 	master->max_dma_len = SPI_MAX_XFER;
 
 	platform_set_drvdata(pdev, master);
diff --git a/drivers/tty/serial/mpsc.c b/drivers/tty/serial/mpsc.c
index 67ffecc..e2f792a 100644
--- a/drivers/tty/serial/mpsc.c
+++ b/drivers/tty/serial/mpsc.c
@@ -81,19 +81,19 @@ 
  * Number of Tx & Rx descriptors must be powers of 2.
  */
 #define	MPSC_RXR_ENTRIES	32
-#define	MPSC_RXRE_SIZE		dma_get_cache_alignment()
+#define	MPSC_RXRE_SIZE		dma_get_cache_alignment(NULL)
 #define	MPSC_RXR_SIZE		(MPSC_RXR_ENTRIES * MPSC_RXRE_SIZE)
-#define	MPSC_RXBE_SIZE		dma_get_cache_alignment()
+#define	MPSC_RXBE_SIZE		dma_get_cache_alignment(NULL)
 #define	MPSC_RXB_SIZE		(MPSC_RXR_ENTRIES * MPSC_RXBE_SIZE)
 
 #define	MPSC_TXR_ENTRIES	32
-#define	MPSC_TXRE_SIZE		dma_get_cache_alignment()
+#define	MPSC_TXRE_SIZE		dma_get_cache_alignment(NULL)
 #define	MPSC_TXR_SIZE		(MPSC_TXR_ENTRIES * MPSC_TXRE_SIZE)
-#define	MPSC_TXBE_SIZE		dma_get_cache_alignment()
+#define	MPSC_TXBE_SIZE		dma_get_cache_alignment(NULL)
 #define	MPSC_TXB_SIZE		(MPSC_TXR_ENTRIES * MPSC_TXBE_SIZE)
 
 #define	MPSC_DMA_ALLOC_SIZE	(MPSC_RXR_SIZE + MPSC_RXB_SIZE + MPSC_TXR_SIZE \
-		+ MPSC_TXB_SIZE + dma_get_cache_alignment() /* for alignment */)
+		+ MPSC_TXB_SIZE + dma_get_cache_alignment(NULL) /* for alignment */)
 
 /* Rx and Tx Ring entry descriptors -- assume entry size is <= cacheline size */
 struct mpsc_rx_desc {
@@ -738,7 +738,7 @@  static void mpsc_init_hw(struct mpsc_port_info *pi)
 
 	mpsc_brg_init(pi, pi->brg_clk_src);
 	mpsc_brg_enable(pi);
-	mpsc_sdma_init(pi, dma_get_cache_alignment());	/* burst a cacheline */
+	mpsc_sdma_init(pi, dma_get_cache_alignment(NULL));	/* burst a cacheline */
 	mpsc_sdma_stop(pi);
 	mpsc_hw_init(pi);
 }
@@ -798,8 +798,8 @@  static void mpsc_init_rings(struct mpsc_port_info *pi)
 	 * Descriptors & buffers are multiples of cacheline size and must be
 	 * cacheline aligned.
 	 */
-	dp = ALIGN((u32)pi->dma_region, dma_get_cache_alignment());
-	dp_p = ALIGN((u32)pi->dma_region_p, dma_get_cache_alignment());
+	dp = ALIGN((u32)pi->dma_region, dma_get_cache_alignment(NULL));
+	dp_p = ALIGN((u32)pi->dma_region_p, dma_get_cache_alignment(NULL));
 
 	/*
 	 * Partition dma region into rx ring descriptor, rx buffers,
diff --git a/drivers/tty/serial/samsung.c b/drivers/tty/serial/samsung.c
index 8aca18c..b40a681 100644
--- a/drivers/tty/serial/samsung.c
+++ b/drivers/tty/serial/samsung.c
@@ -241,7 +241,7 @@  static void enable_tx_dma(struct s3c24xx_uart_port *ourport)
 	/* Enable tx dma mode */
 	ucon = rd_regl(port, S3C2410_UCON);
 	ucon &= ~(S3C64XX_UCON_TXBURST_MASK | S3C64XX_UCON_TXMODE_MASK);
-	ucon |= (dma_get_cache_alignment() >= 16) ?
+	ucon |= (dma_get_cache_alignment(NULL) >= 16) ?
 		S3C64XX_UCON_TXBURST_16 : S3C64XX_UCON_TXBURST_1;
 	ucon |= S3C64XX_UCON_TXMODE_DMA;
 	wr_regl(port,  S3C2410_UCON, ucon);
@@ -292,7 +292,7 @@  static int s3c24xx_serial_start_tx_dma(struct s3c24xx_uart_port *ourport,
 	if (ourport->tx_mode != S3C24XX_TX_DMA)
 		enable_tx_dma(ourport);
 
-	dma->tx_size = count & ~(dma_get_cache_alignment() - 1);
+	dma->tx_size = count & ~(dma_get_cache_alignment(NULL) - 1);
 	dma->tx_transfer_addr = dma->tx_addr + xmit->tail;
 
 	dma_sync_single_for_device(ourport->port.dev, dma->tx_transfer_addr,
@@ -332,7 +332,7 @@  static void s3c24xx_serial_start_next_tx(struct s3c24xx_uart_port *ourport)
 
 	if (!ourport->dma || !ourport->dma->tx_chan ||
 	    count < ourport->min_dma_size ||
-	    xmit->tail & (dma_get_cache_alignment() - 1))
+	    xmit->tail & (dma_get_cache_alignment(NULL) - 1))
 		s3c24xx_serial_start_tx_pio(ourport);
 	else
 		s3c24xx_serial_start_tx_dma(ourport, count);
@@ -718,8 +718,8 @@  static irqreturn_t s3c24xx_serial_tx_chars(int irq, void *id)
 
 	if (ourport->dma && ourport->dma->tx_chan &&
 	    count >= ourport->min_dma_size) {
-		int align = dma_get_cache_alignment() -
-			(xmit->tail & (dma_get_cache_alignment() - 1));
+		int align = dma_get_cache_alignment(NULL) -
+			(xmit->tail & (dma_get_cache_alignment(NULL) - 1));
 		if (count-align >= ourport->min_dma_size) {
 			dma_count = count-align;
 			count = align;
@@ -870,7 +870,7 @@  static int s3c24xx_serial_request_dma(struct s3c24xx_uart_port *p)
 	dma->tx_conf.direction		= DMA_MEM_TO_DEV;
 	dma->tx_conf.dst_addr_width	= DMA_SLAVE_BUSWIDTH_1_BYTE;
 	dma->tx_conf.dst_addr		= p->port.mapbase + S3C2410_UTXH;
-	if (dma_get_cache_alignment() >= 16)
+	if (dma_get_cache_alignment(NULL) >= 16)
 		dma->tx_conf.dst_maxburst = 16;
 	else
 		dma->tx_conf.dst_maxburst = 1;
@@ -1849,7 +1849,7 @@  static int s3c24xx_serial_probe(struct platform_device *pdev)
 	 * so find minimal transfer size suitable for DMA mode
 	 */
 	ourport->min_dma_size = max_t(int, ourport->port.fifosize,
-				    dma_get_cache_alignment());
+				    dma_get_cache_alignment(NULL));
 
 	dbg("%s: initialising port %p...\n", __func__, ourport);
 
diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index 08da227..ef70b0d 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -707,12 +707,16 @@  static inline int device_is_coherent(struct device *dev)
 		return 1;    /* compatible behavior */
 }
 
-static inline int dma_get_cache_alignment(void)
-{
-#ifdef ARCH_DMA_MINALIGN
-	return ARCH_DMA_MINALIGN;
+#ifndef ARCH_DMA_MINALIGN
+#define ARCH_DMA_MINALIGN 1
 #endif
-	return 1;
+
+static inline int dma_get_cache_alignment(struct device *dev)
+{
+	if (dev && device_is_coherent(dev))
+		return 1;
+	else /* dev is NULL or noncoherent */
+		return ARCH_DMA_MINALIGN;
 }
 #endif