diff mbox series

[v8,06/10] hw/fsi: Aspeed APB2OPB interface

Message ID 20231128235700.599584-7-ninad@linux.ibm.com (mailing list archive)
State New, archived
Headers show
Series Introduce model for IBM's FSI | expand

Commit Message

Ninad Palsule Nov. 28, 2023, 11:56 p.m. UTC 
This is a part of patchset where IBM's Flexible Service Interface is
introduced.

An APB-to-OPB bridge enabling access to the OPB from the ARM core in
the AST2600. Hardware limitations prevent the OPB from being directly
mapped into APB, so all accesses are indirect through the bridge.

Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Signed-off-by: Ninad Palsule <ninad@linux.ibm.com>
[ clg: - moved FSIMasterState under AspeedAPB2OPBState
       - modified fsi_opb_fsi_master_address() and
         fsi_opb_opb2fsi_address()
       - instroduced fsi_aspeed_apb2opb_init()
       - reworked fsi_aspeed_apb2opb_realize() ]
Signed-off-by: Cédric Le Goater <clg@kaod.org>
---
 include/hw/fsi/aspeed-apb2opb.h |  34 ++++
 hw/fsi/aspeed-apb2opb.c         | 316 ++++++++++++++++++++++++++++++++
 hw/arm/Kconfig                  |   1 +
 hw/fsi/Kconfig                  |   4 +
 hw/fsi/meson.build              |   1 +
 hw/fsi/trace-events             |   2 +
 6 files changed, 358 insertions(+)
 create mode 100644 include/hw/fsi/aspeed-apb2opb.h
 create mode 100644 hw/fsi/aspeed-apb2opb.c

Comments

Cédric Le Goater Dec. 12, 2023, 2:49 p.m. UTC | #1 
On 11/29/23 00:56, Ninad Palsule wrote:
> This is a part of patchset where IBM's Flexible Service Interface is
> introduced.
> 
> An APB-to-OPB bridge enabling access to the OPB from the ARM core in
> the AST2600. Hardware limitations prevent the OPB from being directly
> mapped into APB, so all accesses are indirect through the bridge.
> 
> Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
> Signed-off-by: Ninad Palsule <ninad@linux.ibm.com>
> [ clg: - moved FSIMasterState under AspeedAPB2OPBState
>         - modified fsi_opb_fsi_master_address() and
>           fsi_opb_opb2fsi_address()
>         - instroduced fsi_aspeed_apb2opb_init()
>         - reworked fsi_aspeed_apb2opb_realize() ]
> Signed-off-by: Cédric Le Goater <clg@kaod.org>
> ---
>   include/hw/fsi/aspeed-apb2opb.h |  34 ++++
>   hw/fsi/aspeed-apb2opb.c         | 316 ++++++++++++++++++++++++++++++++
>   hw/arm/Kconfig                  |   1 +
>   hw/fsi/Kconfig                  |   4 +
>   hw/fsi/meson.build              |   1 +
>   hw/fsi/trace-events             |   2 +
>   6 files changed, 358 insertions(+)
>   create mode 100644 include/hw/fsi/aspeed-apb2opb.h
>   create mode 100644 hw/fsi/aspeed-apb2opb.c
> 
> diff --git a/include/hw/fsi/aspeed-apb2opb.h b/include/hw/fsi/aspeed-apb2opb.h
> new file mode 100644
> index 0000000000..c51fbeda9f
> --- /dev/null
> +++ b/include/hw/fsi/aspeed-apb2opb.h
> @@ -0,0 +1,34 @@
> +/*
> + * SPDX-License-Identifier: GPL-2.0-or-later
> + * Copyright (C) 2023 IBM Corp.
> + *
> + * ASPEED APB2OPB Bridge
> + */
> +#ifndef FSI_ASPEED_APB2OPB_H
> +#define FSI_ASPEED_APB2OPB_H
> +
> +#include "hw/sysbus.h"
> +#include "hw/fsi/opb.h"
> +
> +#define TYPE_ASPEED_APB2OPB "aspeed.apb2opb"
> +OBJECT_DECLARE_SIMPLE_TYPE(AspeedAPB2OPBState, ASPEED_APB2OPB)
> +
> +#define ASPEED_APB2OPB_NR_REGS ((0xe8 >> 2) + 1)
> +
> +#define ASPEED_FSI_NUM 2
> +
> +typedef struct AspeedAPB2OPBState {
> +    /*< private >*/
> +    SysBusDevice parent_obj;
> +
> +    /*< public >*/
> +    MemoryRegion iomem;
> +
> +    uint32_t regs[ASPEED_APB2OPB_NR_REGS];
> +    qemu_irq irq;
> +
> +    OPBus opb[ASPEED_FSI_NUM];
> +    FSIMasterState fsi[ASPEED_FSI_NUM];
> +} AspeedAPB2OPBState;
> +
> +#endif /* FSI_ASPEED_APB2OPB_H */
> diff --git a/hw/fsi/aspeed-apb2opb.c b/hw/fsi/aspeed-apb2opb.c
> new file mode 100644
> index 0000000000..70b3fe2587
> --- /dev/null
> +++ b/hw/fsi/aspeed-apb2opb.c
> @@ -0,0 +1,316 @@
> +/*
> + * SPDX-License-Identifier: GPL-2.0-or-later
> + * Copyright (C) 2023 IBM Corp.
> + *
> + * ASPEED APB-OPB FSI interface
> + */
> +
> +#include "qemu/osdep.h"
> +#include "qemu/log.h"
> +#include "qom/object.h"
> +#include "qapi/error.h"
> +#include "trace.h"
> +
> +#include "hw/fsi/aspeed-apb2opb.h"
> +#include "hw/qdev-core.h"
> +
> +#define TO_REG(x) (x >> 2)
> +
> +#define APB2OPB_VERSION                    TO_REG(0x00)
> +#define APB2OPB_TRIGGER                    TO_REG(0x04)
> +
> +#define APB2OPB_CONTROL                    TO_REG(0x08)
> +#define   APB2OPB_CONTROL_OFF              BE_GENMASK(31, 13)
> +
> +#define APB2OPB_OPB2FSI                    TO_REG(0x0c)
> +#define   APB2OPB_OPB2FSI_OFF              BE_GENMASK(31, 22)
> +
> +#define APB2OPB_OPB0_SEL                   TO_REG(0x10)
> +#define APB2OPB_OPB1_SEL                   TO_REG(0x28)
> +#define   APB2OPB_OPB_SEL_EN               BIT(0)
> +
> +#define APB2OPB_OPB0_MODE                  TO_REG(0x14)
> +#define APB2OPB_OPB1_MODE                  TO_REG(0x2c)
> +#define   APB2OPB_OPB_MODE_RD              BIT(0)
> +
> +#define APB2OPB_OPB0_XFER                  TO_REG(0x18)
> +#define APB2OPB_OPB1_XFER                  TO_REG(0x30)
> +#define   APB2OPB_OPB_XFER_FULL            BIT(1)
> +#define   APB2OPB_OPB_XFER_HALF            BIT(0)
> +
> +#define APB2OPB_OPB0_ADDR                  TO_REG(0x1c)
> +#define APB2OPB_OPB0_WRITE_DATA            TO_REG(0x20)
> +
> +#define APB2OPB_OPB1_ADDR                  TO_REG(0x34)
> +#define APB2OPB_OPB1_WRITE_DATA                  TO_REG(0x38)
> +
> +#define APB2OPB_IRQ_STS                    TO_REG(0x48)
> +#define   APB2OPB_IRQ_STS_OPB1_TX_ACK      BIT(17)
> +#define   APB2OPB_IRQ_STS_OPB0_TX_ACK      BIT(16)
> +
> +#define APB2OPB_OPB0_WRITE_WORD_ENDIAN     TO_REG(0x4c)
> +#define   APB2OPB_OPB0_WRITE_WORD_ENDIAN_BE 0x0011101b
> +#define APB2OPB_OPB0_WRITE_BYTE_ENDIAN     TO_REG(0x50)
> +#define   APB2OPB_OPB0_WRITE_BYTE_ENDIAN_BE 0x0c330f3f
> +#define APB2OPB_OPB1_WRITE_WORD_ENDIAN     TO_REG(0x54)
> +#define APB2OPB_OPB1_WRITE_BYTE_ENDIAN     TO_REG(0x58)
> +#define APB2OPB_OPB0_READ_BYTE_ENDIAN      TO_REG(0x5c)
> +#define APB2OPB_OPB1_READ_BYTE_ENDIAN      TO_REG(0x60)
> +#define   APB2OPB_OPB0_READ_WORD_ENDIAN_BE  0x00030b1b
> +
> +#define APB2OPB_OPB0_READ_DATA         TO_REG(0x84)
> +#define APB2OPB_OPB1_READ_DATA         TO_REG(0x90)
> +
> +/*
> + * The following magic values came from AST2600 data sheet
> + * The register values are defined under section "FSI controller"
> + * as initial values.
> + */
> +static const uint32_t aspeed_apb2opb_reset[ASPEED_APB2OPB_NR_REGS] = {
> +     [APB2OPB_VERSION]                = 0x000000a1,
> +     [APB2OPB_OPB0_WRITE_WORD_ENDIAN] = 0x0044eee4,
> +     [APB2OPB_OPB0_WRITE_BYTE_ENDIAN] = 0x0055aaff,
> +     [APB2OPB_OPB1_WRITE_WORD_ENDIAN] = 0x00117717,
> +     [APB2OPB_OPB1_WRITE_BYTE_ENDIAN] = 0xffaa5500,
> +     [APB2OPB_OPB0_READ_BYTE_ENDIAN]  = 0x0044eee4,
> +     [APB2OPB_OPB1_READ_BYTE_ENDIAN]  = 0x00117717
> +};
> +
> +static void fsi_opb_fsi_master_address(OPBus *opb, FSIMasterState* fsi,
> +                                       hwaddr addr)

opb parameter is not useful anymore.

> +{
> +    memory_region_transaction_begin();
> +    memory_region_set_address(&fsi->iomem, addr);
> +    memory_region_transaction_commit();
> +}
> +
> +static void fsi_opb_opb2fsi_address(OPBus *opb, FSIMasterState* fsi,
> +                                    hwaddr addr)

same here.

> +{
> +    memory_region_transaction_begin();
> +    memory_region_set_address(&fsi->opb2fsi, addr);
> +    memory_region_transaction_commit();
> +}
> +
> +static uint64_t fsi_aspeed_apb2opb_read(void *opaque, hwaddr addr,
> +                                        unsigned size)
> +{
> +    AspeedAPB2OPBState *s = ASPEED_APB2OPB(opaque);
> +    unsigned int reg = TO_REG(addr);
> +
> +    trace_fsi_aspeed_apb2opb_read(addr, size);
> +
> +    if (reg >= ASPEED_APB2OPB_NR_REGS) {
> +        qemu_log_mask(LOG_GUEST_ERROR,
> +                      "%s: Out of bounds read: 0x%"HWADDR_PRIx" for %u\n",
> +                      __func__, addr, size);
> +        return 0;
> +    }
> +
> +    return s->regs[reg];
> +}
> +
> +static void fsi_aspeed_apb2opb_write(void *opaque, hwaddr addr, uint64_t data,
> +                                     unsigned size)
> +{
> +    AspeedAPB2OPBState *s = ASPEED_APB2OPB(opaque);
> +    unsigned int reg = TO_REG(addr);
> +
> +    trace_fsi_aspeed_apb2opb_write(addr, size, data);
> +
> +    if (reg >= ASPEED_APB2OPB_NR_REGS) {
> +        qemu_log_mask(LOG_GUEST_ERROR,
> +                      "%s: Out of bounds write: %"HWADDR_PRIx" for %u\n",
> +                      __func__, addr, size);
> +        return;
> +    }
> +
> +    switch (reg) {
> +    case APB2OPB_CONTROL:
> +        fsi_opb_fsi_master_address(&s->opb[0], &s->fsi[0],
> +                data & APB2OPB_CONTROL_OFF);
> +        break;
> +    case APB2OPB_OPB2FSI:
> +        fsi_opb_opb2fsi_address(&s->opb[0], &s->fsi[0],
> +                data & APB2OPB_OPB2FSI_OFF);
> +        break;
> +    case APB2OPB_OPB0_WRITE_WORD_ENDIAN:
> +        if (data != APB2OPB_OPB0_WRITE_WORD_ENDIAN_BE) {
> +            qemu_log_mask(LOG_GUEST_ERROR,
> +                          "%s: Bridge needs to be driven as BE (0x%x)\n",
> +                          __func__, APB2OPB_OPB0_WRITE_WORD_ENDIAN_BE);
> +        }
> +        break;
> +    case APB2OPB_OPB0_WRITE_BYTE_ENDIAN:
> +        if (data != APB2OPB_OPB0_WRITE_BYTE_ENDIAN_BE) {
> +            qemu_log_mask(LOG_GUEST_ERROR,
> +                          "%s: Bridge needs to be driven as BE (0x%x)\n",
> +                          __func__, APB2OPB_OPB0_WRITE_BYTE_ENDIAN_BE);
> +        }
> +        break;
> +    case APB2OPB_OPB0_READ_BYTE_ENDIAN:
> +        if (data != APB2OPB_OPB0_READ_WORD_ENDIAN_BE) {
> +            qemu_log_mask(LOG_GUEST_ERROR,
> +                          "%s: Bridge needs to be driven as BE (0x%x)\n",
> +                          __func__, APB2OPB_OPB0_READ_WORD_ENDIAN_BE);
> +        }
> +        break;
> +    case APB2OPB_TRIGGER:
> +    {
> +        uint32_t opb, op_mode, op_size, op_addr, op_data;
> +        MemTxResult result;
> +        bool is_write;
> +        int index;
> +        AddressSpace *as;
> +
> +        assert((s->regs[APB2OPB_OPB0_SEL] & APB2OPB_OPB_SEL_EN) ^
> +               (s->regs[APB2OPB_OPB1_SEL] & APB2OPB_OPB_SEL_EN));
> +
> +        if (s->regs[APB2OPB_OPB0_SEL] & APB2OPB_OPB_SEL_EN) {
> +            opb = 0;
> +            op_mode = s->regs[APB2OPB_OPB0_MODE];
> +            op_size = s->regs[APB2OPB_OPB0_XFER];
> +            op_addr = s->regs[APB2OPB_OPB0_ADDR];
> +            op_data = s->regs[APB2OPB_OPB0_WRITE_DATA];
> +        } else if (s->regs[APB2OPB_OPB1_SEL] & APB2OPB_OPB_SEL_EN) {
> +            opb = 1;
> +            op_mode = s->regs[APB2OPB_OPB1_MODE];
> +            op_size = s->regs[APB2OPB_OPB1_XFER];
> +            op_addr = s->regs[APB2OPB_OPB1_ADDR];
> +            op_data = s->regs[APB2OPB_OPB1_WRITE_DATA];
> +        } else {
> +            qemu_log_mask(LOG_GUEST_ERROR,
> +                          "%s: Invalid operation: 0x%"HWADDR_PRIx" for %u\n",
> +                          __func__, addr, size);
> +            return;
> +        }
> +
> +        if (op_size & ~(APB2OPB_OPB_XFER_HALF | APB2OPB_OPB_XFER_FULL)) {
> +            qemu_log_mask(LOG_GUEST_ERROR,
> +                          "OPB transaction failed: Unrecognized access width: %d\n",
> +                          op_size);
> +            return;
> +        }
> +
> +        op_size += 1;
> +        is_write = !(op_mode & APB2OPB_OPB_MODE_RD);
> +        index = opb ? APB2OPB_OPB1_READ_DATA : APB2OPB_OPB0_READ_DATA;
> +        as = &s->opb[opb].as;
> +
> +        result = address_space_rw(as, op_addr, MEMTXATTRS_UNSPECIFIED,
> +                                  &op_data, op_size, is_write);
> +        if (result != MEMTX_OK) {
> +            qemu_log_mask(LOG_GUEST_ERROR, "%s: OPB %s failed @%08x\n",
> +                          __func__, is_write ? "write" : "read", op_addr);
> +            return;
> +        }
> +
> +        if (!is_write) {
> +            s->regs[index] = op_data;
> +        }
> +
> +        s->regs[APB2OPB_IRQ_STS] |= opb ? APB2OPB_IRQ_STS_OPB1_TX_ACK
> +            : APB2OPB_IRQ_STS_OPB0_TX_ACK;
> +        break;
> +    }
> +    }
> +
> +    s->regs[reg] = data;
> +}
> +
> +static const struct MemoryRegionOps aspeed_apb2opb_ops = {
> +    .read = fsi_aspeed_apb2opb_read,
> +    .write = fsi_aspeed_apb2opb_write,
> +    .valid.max_access_size = 4,
> +    .valid.min_access_size = 4,
> +    .impl.max_access_size = 4,
> +    .impl.min_access_size = 4,
> +    .endianness = DEVICE_LITTLE_ENDIAN,
> +};
> +
> +static void fsi_aspeed_apb2opb_init(Object *o)
> +{
> +    AspeedAPB2OPBState *s = ASPEED_APB2OPB(o);
> +    int i;
> +
> +    for (i = 0; i < ASPEED_FSI_NUM; i++) {
> +        qbus_init(&s->opb[i], sizeof(s->opb[i]), TYPE_OP_BUS, DEVICE(s),
> +                  NULL);
> +    }
> +
> +    for (i = 0; i < ASPEED_FSI_NUM; i++) {
> +        object_initialize_child(o, "fsi-master[*]", &s->fsi[i],
> +                                TYPE_FSI_MASTER);
> +    }
> +}
> +
> +static void fsi_aspeed_apb2opb_realize(DeviceState *dev, Error **errp)
> +{
> +    SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
> +    AspeedAPB2OPBState *s = ASPEED_APB2OPB(dev);
> +    int i;
> +
> +    sysbus_init_irq(sbd, &s->irq);
> +
> +    memory_region_init_io(&s->iomem, OBJECT(s), &aspeed_apb2opb_ops, s,
> +                          TYPE_ASPEED_APB2OPB, 0x1000);
> +    sysbus_init_mmio(sbd, &s->iomem);
> +
> +    for (i = 0; i < ASPEED_FSI_NUM; i++) {
> +        if (!qdev_realize_and_unref(DEVICE(&s->fsi[i]), BUS(&s->opb[i]),


s->fsi[i] is not allocated. We should use qdev_realize instead.


Thanks,

C.



> +                errp)) {
> +            return;
> +        }
> +
> +        memory_region_add_subregion(&s->opb[i].mr, 0x80000000,
> +                &s->fsi[i].iomem);
> +
> +        /* OPB2FSI region */
> +        /*
> +         * Avoid endianness issues by mapping each slave's memory region
> +         * directly. Manually bridging multiple address-spaces causes endian
> +         * swapping headaches as memory_region_dispatch_read() and
> +         * memory_region_dispatch_write() correct the endianness based on the
> +         * target machine endianness and not relative to the device endianness
> +         * on either side of the bridge.
> +         */
> +        /*
> +         * XXX: This is a bit hairy and will need to be fixed when I sort out
> +         * the bus/slave relationship and any changes to the CFAM modelling
> +         * (multiple slaves, LBUS)
> +         */
> +        memory_region_add_subregion(&s->opb[i].mr, 0xa0000000,
> +                &s->fsi[i].opb2fsi);
> +    }
> +}
> +
> +static void fsi_aspeed_apb2opb_reset(DeviceState *dev)
> +{
> +    AspeedAPB2OPBState *s = ASPEED_APB2OPB(dev);
> +
> +    memcpy(s->regs, aspeed_apb2opb_reset, ASPEED_APB2OPB_NR_REGS);
> +}
> +
> +static void fsi_aspeed_apb2opb_class_init(ObjectClass *klass, void *data)
> +{
> +    DeviceClass *dc = DEVICE_CLASS(klass);
> +
> +    dc->desc = "ASPEED APB2OPB Bridge";
> +    dc->realize = fsi_aspeed_apb2opb_realize;
> +    dc->reset = fsi_aspeed_apb2opb_reset;
> +}
> +
> +static const TypeInfo aspeed_apb2opb_info = {
> +    .name = TYPE_ASPEED_APB2OPB,
> +    .parent = TYPE_SYS_BUS_DEVICE,
> +    .instance_init = fsi_aspeed_apb2opb_init,
> +    .instance_size = sizeof(AspeedAPB2OPBState),
> +    .class_init = fsi_aspeed_apb2opb_class_init,
> +};
> +
> +static void aspeed_apb2opb_register_types(void)
> +{
> +    type_register_static(&aspeed_apb2opb_info);
> +}
> +
> +type_init(aspeed_apb2opb_register_types);
> diff --git a/hw/arm/Kconfig b/hw/arm/Kconfig
> index 3ada335a24..0a3bc712a4 100644
> --- a/hw/arm/Kconfig
> +++ b/hw/arm/Kconfig
> @@ -559,6 +559,7 @@ config ASPEED_SOC
>       select LED
>       select PMBUS
>       select MAX31785
> +    select FSI_APB2OPB_ASPEED
>   
>   config MPS2
>       bool
> diff --git a/hw/fsi/Kconfig b/hw/fsi/Kconfig
> index 9755baa8cc..9e92b07930 100644
> --- a/hw/fsi/Kconfig
> +++ b/hw/fsi/Kconfig
> @@ -1,3 +1,7 @@
> +config FSI_APB2OPB_ASPEED
> +    bool
> +    select FSI_OPB
> +
>   config FSI_OPB
>       bool
>       select FSI_CFAM
> diff --git a/hw/fsi/meson.build b/hw/fsi/meson.build
> index 038c4468ee..d0910627f9 100644
> --- a/hw/fsi/meson.build
> +++ b/hw/fsi/meson.build
> @@ -2,3 +2,4 @@ system_ss.add(when: 'CONFIG_FSI_LBUS', if_true: files('lbus.c'))
>   system_ss.add(when: 'CONFIG_FSI_CFAM', if_true: files('cfam.c'))
>   system_ss.add(when: 'CONFIG_FSI', if_true: files('fsi.c','fsi-master.c','fsi-slave.c'))
>   system_ss.add(when: 'CONFIG_FSI_OPB', if_true: files('opb.c'))
> +system_ss.add(when: 'CONFIG_FSI_APB2OPB_ASPEED', if_true: files('aspeed-apb2opb.c'))
> diff --git a/hw/fsi/trace-events b/hw/fsi/trace-events
> index 89d8cd62c8..3af4755995 100644
> --- a/hw/fsi/trace-events
> +++ b/hw/fsi/trace-events
> @@ -9,3 +9,5 @@ fsi_slave_read(uint64_t addr, uint32_t size) "@0x%" PRIx64 " size=%d"
>   fsi_slave_write(uint64_t addr, uint32_t size, uint64_t data) "@0x%" PRIx64 " size=%d value=0x%"PRIx64
>   fsi_master_read(uint64_t addr, uint32_t size) "@0x%" PRIx64 " size=%d"
>   fsi_master_write(uint64_t addr, uint32_t size, uint64_t data) "@0x%" PRIx64 " size=%d value=0x%"PRIx64
> +fsi_aspeed_apb2opb_read(uint64_t addr, uint32_t size) "@0x%" PRIx64 " size=%d"
> +fsi_aspeed_apb2opb_write(uint64_t addr, uint32_t size, uint64_t data) "@0x%" PRIx64 " size=%d value=0x%"PRIx64
Ninad Palsule Jan. 8, 2024, 10:39 p.m. UTC | #2 
Hello Cedric,

On 12/12/23 08:49, Cédric Le Goater wrote:
> On 11/29/23 00:56, Ninad Palsule wrote:
>> This is a part of patchset where IBM's Flexible Service Interface is
>> introduced.
>>
>> An APB-to-OPB bridge enabling access to the OPB from the ARM core in
>> the AST2600. Hardware limitations prevent the OPB from being directly
>> mapped into APB, so all accesses are indirect through the bridge.
>>
>> Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
>> Signed-off-by: Ninad Palsule <ninad@linux.ibm.com>
>> [ clg: - moved FSIMasterState under AspeedAPB2OPBState
>>         - modified fsi_opb_fsi_master_address() and
>>           fsi_opb_opb2fsi_address()
>>         - instroduced fsi_aspeed_apb2opb_init()
>>         - reworked fsi_aspeed_apb2opb_realize() ]
>> Signed-off-by: Cédric Le Goater <clg@kaod.org>
>> ---
>>   include/hw/fsi/aspeed-apb2opb.h |  34 ++++
>>   hw/fsi/aspeed-apb2opb.c         | 316 ++++++++++++++++++++++++++++++++
>>   hw/arm/Kconfig                  |   1 +
>>   hw/fsi/Kconfig                  |   4 +
>>   hw/fsi/meson.build              |   1 +
>>   hw/fsi/trace-events             |   2 +
>>   6 files changed, 358 insertions(+)
>>   create mode 100644 include/hw/fsi/aspeed-apb2opb.h
>>   create mode 100644 hw/fsi/aspeed-apb2opb.c
>>
>> diff --git a/include/hw/fsi/aspeed-apb2opb.h 
>> b/include/hw/fsi/aspeed-apb2opb.h
>> new file mode 100644
>> index 0000000000..c51fbeda9f
>> --- /dev/null
>> +++ b/include/hw/fsi/aspeed-apb2opb.h
>> @@ -0,0 +1,34 @@
>> +/*
>> + * SPDX-License-Identifier: GPL-2.0-or-later
>> + * Copyright (C) 2023 IBM Corp.
>> + *
>> + * ASPEED APB2OPB Bridge
>> + */
>> +#ifndef FSI_ASPEED_APB2OPB_H
>> +#define FSI_ASPEED_APB2OPB_H
>> +
>> +#include "hw/sysbus.h"
>> +#include "hw/fsi/opb.h"
>> +
>> +#define TYPE_ASPEED_APB2OPB "aspeed.apb2opb"
>> +OBJECT_DECLARE_SIMPLE_TYPE(AspeedAPB2OPBState, ASPEED_APB2OPB)
>> +
>> +#define ASPEED_APB2OPB_NR_REGS ((0xe8 >> 2) + 1)
>> +
>> +#define ASPEED_FSI_NUM 2
>> +
>> +typedef struct AspeedAPB2OPBState {
>> +    /*< private >*/
>> +    SysBusDevice parent_obj;
>> +
>> +    /*< public >*/
>> +    MemoryRegion iomem;
>> +
>> +    uint32_t regs[ASPEED_APB2OPB_NR_REGS];
>> +    qemu_irq irq;
>> +
>> +    OPBus opb[ASPEED_FSI_NUM];
>> +    FSIMasterState fsi[ASPEED_FSI_NUM];
>> +} AspeedAPB2OPBState;
>> +
>> +#endif /* FSI_ASPEED_APB2OPB_H */
>> diff --git a/hw/fsi/aspeed-apb2opb.c b/hw/fsi/aspeed-apb2opb.c
>> new file mode 100644
>> index 0000000000..70b3fe2587
>> --- /dev/null
>> +++ b/hw/fsi/aspeed-apb2opb.c
>> @@ -0,0 +1,316 @@
>> +/*
>> + * SPDX-License-Identifier: GPL-2.0-or-later
>> + * Copyright (C) 2023 IBM Corp.
>> + *
>> + * ASPEED APB-OPB FSI interface
>> + */
>> +
>> +#include "qemu/osdep.h"
>> +#include "qemu/log.h"
>> +#include "qom/object.h"
>> +#include "qapi/error.h"
>> +#include "trace.h"
>> +
>> +#include "hw/fsi/aspeed-apb2opb.h"
>> +#include "hw/qdev-core.h"
>> +
>> +#define TO_REG(x) (x >> 2)
>> +
>> +#define APB2OPB_VERSION                    TO_REG(0x00)
>> +#define APB2OPB_TRIGGER                    TO_REG(0x04)
>> +
>> +#define APB2OPB_CONTROL                    TO_REG(0x08)
>> +#define   APB2OPB_CONTROL_OFF              BE_GENMASK(31, 13)
>> +
>> +#define APB2OPB_OPB2FSI                    TO_REG(0x0c)
>> +#define   APB2OPB_OPB2FSI_OFF              BE_GENMASK(31, 22)
>> +
>> +#define APB2OPB_OPB0_SEL                   TO_REG(0x10)
>> +#define APB2OPB_OPB1_SEL                   TO_REG(0x28)
>> +#define   APB2OPB_OPB_SEL_EN               BIT(0)
>> +
>> +#define APB2OPB_OPB0_MODE                  TO_REG(0x14)
>> +#define APB2OPB_OPB1_MODE                  TO_REG(0x2c)
>> +#define   APB2OPB_OPB_MODE_RD              BIT(0)
>> +
>> +#define APB2OPB_OPB0_XFER                  TO_REG(0x18)
>> +#define APB2OPB_OPB1_XFER                  TO_REG(0x30)
>> +#define   APB2OPB_OPB_XFER_FULL            BIT(1)
>> +#define   APB2OPB_OPB_XFER_HALF            BIT(0)
>> +
>> +#define APB2OPB_OPB0_ADDR                  TO_REG(0x1c)
>> +#define APB2OPB_OPB0_WRITE_DATA            TO_REG(0x20)
>> +
>> +#define APB2OPB_OPB1_ADDR                  TO_REG(0x34)
>> +#define APB2OPB_OPB1_WRITE_DATA                  TO_REG(0x38)
>> +
>> +#define APB2OPB_IRQ_STS                    TO_REG(0x48)
>> +#define   APB2OPB_IRQ_STS_OPB1_TX_ACK      BIT(17)
>> +#define   APB2OPB_IRQ_STS_OPB0_TX_ACK      BIT(16)
>> +
>> +#define APB2OPB_OPB0_WRITE_WORD_ENDIAN     TO_REG(0x4c)
>> +#define   APB2OPB_OPB0_WRITE_WORD_ENDIAN_BE 0x0011101b
>> +#define APB2OPB_OPB0_WRITE_BYTE_ENDIAN     TO_REG(0x50)
>> +#define   APB2OPB_OPB0_WRITE_BYTE_ENDIAN_BE 0x0c330f3f
>> +#define APB2OPB_OPB1_WRITE_WORD_ENDIAN     TO_REG(0x54)
>> +#define APB2OPB_OPB1_WRITE_BYTE_ENDIAN     TO_REG(0x58)
>> +#define APB2OPB_OPB0_READ_BYTE_ENDIAN      TO_REG(0x5c)
>> +#define APB2OPB_OPB1_READ_BYTE_ENDIAN      TO_REG(0x60)
>> +#define   APB2OPB_OPB0_READ_WORD_ENDIAN_BE  0x00030b1b
>> +
>> +#define APB2OPB_OPB0_READ_DATA         TO_REG(0x84)
>> +#define APB2OPB_OPB1_READ_DATA         TO_REG(0x90)
>> +
>> +/*
>> + * The following magic values came from AST2600 data sheet
>> + * The register values are defined under section "FSI controller"
>> + * as initial values.
>> + */
>> +static const uint32_t aspeed_apb2opb_reset[ASPEED_APB2OPB_NR_REGS] = {
>> +     [APB2OPB_VERSION]                = 0x000000a1,
>> +     [APB2OPB_OPB0_WRITE_WORD_ENDIAN] = 0x0044eee4,
>> +     [APB2OPB_OPB0_WRITE_BYTE_ENDIAN] = 0x0055aaff,
>> +     [APB2OPB_OPB1_WRITE_WORD_ENDIAN] = 0x00117717,
>> +     [APB2OPB_OPB1_WRITE_BYTE_ENDIAN] = 0xffaa5500,
>> +     [APB2OPB_OPB0_READ_BYTE_ENDIAN]  = 0x0044eee4,
>> +     [APB2OPB_OPB1_READ_BYTE_ENDIAN]  = 0x00117717
>> +};
>> +
>> +static void fsi_opb_fsi_master_address(OPBus *opb, FSIMasterState* fsi,
>> +                                       hwaddr addr)
>
> opb parameter is not useful anymore.
Removed.
>
>> +{
>> +    memory_region_transaction_begin();
>> +    memory_region_set_address(&fsi->iomem, addr);
>> +    memory_region_transaction_commit();
>> +}
>> +
>> +static void fsi_opb_opb2fsi_address(OPBus *opb, FSIMasterState* fsi,
>> +                                    hwaddr addr)
>
> same here.
Removed.
>
>> +{
>> +    memory_region_transaction_begin();
>> +    memory_region_set_address(&fsi->opb2fsi, addr);
>> +    memory_region_transaction_commit();
>> +}
>> +
>> +static uint64_t fsi_aspeed_apb2opb_read(void *opaque, hwaddr addr,
>> +                                        unsigned size)
>> +{
>> +    AspeedAPB2OPBState *s = ASPEED_APB2OPB(opaque);
>> +    unsigned int reg = TO_REG(addr);
>> +
>> +    trace_fsi_aspeed_apb2opb_read(addr, size);
>> +
>> +    if (reg >= ASPEED_APB2OPB_NR_REGS) {
>> +        qemu_log_mask(LOG_GUEST_ERROR,
>> +                      "%s: Out of bounds read: 0x%"HWADDR_PRIx" for 
>> %u\n",
>> +                      __func__, addr, size);
>> +        return 0;
>> +    }
>> +
>> +    return s->regs[reg];
>> +}
>> +
>> +static void fsi_aspeed_apb2opb_write(void *opaque, hwaddr addr, 
>> uint64_t data,
>> +                                     unsigned size)
>> +{
>> +    AspeedAPB2OPBState *s = ASPEED_APB2OPB(opaque);
>> +    unsigned int reg = TO_REG(addr);
>> +
>> +    trace_fsi_aspeed_apb2opb_write(addr, size, data);
>> +
>> +    if (reg >= ASPEED_APB2OPB_NR_REGS) {
>> +        qemu_log_mask(LOG_GUEST_ERROR,
>> +                      "%s: Out of bounds write: %"HWADDR_PRIx" for 
>> %u\n",
>> +                      __func__, addr, size);
>> +        return;
>> +    }
>> +
>> +    switch (reg) {
>> +    case APB2OPB_CONTROL:
>> +        fsi_opb_fsi_master_address(&s->opb[0], &s->fsi[0],
>> +                data & APB2OPB_CONTROL_OFF);
>> +        break;
>> +    case APB2OPB_OPB2FSI:
>> +        fsi_opb_opb2fsi_address(&s->opb[0], &s->fsi[0],
>> +                data & APB2OPB_OPB2FSI_OFF);
>> +        break;
>> +    case APB2OPB_OPB0_WRITE_WORD_ENDIAN:
>> +        if (data != APB2OPB_OPB0_WRITE_WORD_ENDIAN_BE) {
>> +            qemu_log_mask(LOG_GUEST_ERROR,
>> +                          "%s: Bridge needs to be driven as BE 
>> (0x%x)\n",
>> +                          __func__, APB2OPB_OPB0_WRITE_WORD_ENDIAN_BE);
>> +        }
>> +        break;
>> +    case APB2OPB_OPB0_WRITE_BYTE_ENDIAN:
>> +        if (data != APB2OPB_OPB0_WRITE_BYTE_ENDIAN_BE) {
>> +            qemu_log_mask(LOG_GUEST_ERROR,
>> +                          "%s: Bridge needs to be driven as BE 
>> (0x%x)\n",
>> +                          __func__, APB2OPB_OPB0_WRITE_BYTE_ENDIAN_BE);
>> +        }
>> +        break;
>> +    case APB2OPB_OPB0_READ_BYTE_ENDIAN:
>> +        if (data != APB2OPB_OPB0_READ_WORD_ENDIAN_BE) {
>> +            qemu_log_mask(LOG_GUEST_ERROR,
>> +                          "%s: Bridge needs to be driven as BE 
>> (0x%x)\n",
>> +                          __func__, APB2OPB_OPB0_READ_WORD_ENDIAN_BE);
>> +        }
>> +        break;
>> +    case APB2OPB_TRIGGER:
>> +    {
>> +        uint32_t opb, op_mode, op_size, op_addr, op_data;
>> +        MemTxResult result;
>> +        bool is_write;
>> +        int index;
>> +        AddressSpace *as;
>> +
>> +        assert((s->regs[APB2OPB_OPB0_SEL] & APB2OPB_OPB_SEL_EN) ^
>> +               (s->regs[APB2OPB_OPB1_SEL] & APB2OPB_OPB_SEL_EN));
>> +
>> +        if (s->regs[APB2OPB_OPB0_SEL] & APB2OPB_OPB_SEL_EN) {
>> +            opb = 0;
>> +            op_mode = s->regs[APB2OPB_OPB0_MODE];
>> +            op_size = s->regs[APB2OPB_OPB0_XFER];
>> +            op_addr = s->regs[APB2OPB_OPB0_ADDR];
>> +            op_data = s->regs[APB2OPB_OPB0_WRITE_DATA];
>> +        } else if (s->regs[APB2OPB_OPB1_SEL] & APB2OPB_OPB_SEL_EN) {
>> +            opb = 1;
>> +            op_mode = s->regs[APB2OPB_OPB1_MODE];
>> +            op_size = s->regs[APB2OPB_OPB1_XFER];
>> +            op_addr = s->regs[APB2OPB_OPB1_ADDR];
>> +            op_data = s->regs[APB2OPB_OPB1_WRITE_DATA];
>> +        } else {
>> +            qemu_log_mask(LOG_GUEST_ERROR,
>> +                          "%s: Invalid operation: 0x%"HWADDR_PRIx" 
>> for %u\n",
>> +                          __func__, addr, size);
>> +            return;
>> +        }
>> +
>> +        if (op_size & ~(APB2OPB_OPB_XFER_HALF | 
>> APB2OPB_OPB_XFER_FULL)) {
>> +            qemu_log_mask(LOG_GUEST_ERROR,
>> +                          "OPB transaction failed: Unrecognized 
>> access width: %d\n",
>> +                          op_size);
>> +            return;
>> +        }
>> +
>> +        op_size += 1;
>> +        is_write = !(op_mode & APB2OPB_OPB_MODE_RD);
>> +        index = opb ? APB2OPB_OPB1_READ_DATA : APB2OPB_OPB0_READ_DATA;
>> +        as = &s->opb[opb].as;
>> +
>> +        result = address_space_rw(as, op_addr, MEMTXATTRS_UNSPECIFIED,
>> +                                  &op_data, op_size, is_write);
>> +        if (result != MEMTX_OK) {
>> +            qemu_log_mask(LOG_GUEST_ERROR, "%s: OPB %s failed @%08x\n",
>> +                          __func__, is_write ? "write" : "read", 
>> op_addr);
>> +            return;
>> +        }
>> +
>> +        if (!is_write) {
>> +            s->regs[index] = op_data;
>> +        }
>> +
>> +        s->regs[APB2OPB_IRQ_STS] |= opb ? APB2OPB_IRQ_STS_OPB1_TX_ACK
>> +            : APB2OPB_IRQ_STS_OPB0_TX_ACK;
>> +        break;
>> +    }
>> +    }
>> +
>> +    s->regs[reg] = data;
>> +}
>> +
>> +static const struct MemoryRegionOps aspeed_apb2opb_ops = {
>> +    .read = fsi_aspeed_apb2opb_read,
>> +    .write = fsi_aspeed_apb2opb_write,
>> +    .valid.max_access_size = 4,
>> +    .valid.min_access_size = 4,
>> +    .impl.max_access_size = 4,
>> +    .impl.min_access_size = 4,
>> +    .endianness = DEVICE_LITTLE_ENDIAN,
>> +};
>> +
>> +static void fsi_aspeed_apb2opb_init(Object *o)
>> +{
>> +    AspeedAPB2OPBState *s = ASPEED_APB2OPB(o);
>> +    int i;
>> +
>> +    for (i = 0; i < ASPEED_FSI_NUM; i++) {
>> +        qbus_init(&s->opb[i], sizeof(s->opb[i]), TYPE_OP_BUS, 
>> DEVICE(s),
>> +                  NULL);
>> +    }
>> +
>> +    for (i = 0; i < ASPEED_FSI_NUM; i++) {
>> +        object_initialize_child(o, "fsi-master[*]", &s->fsi[i],
>> +                                TYPE_FSI_MASTER);
>> +    }
>> +}
>> +
>> +static void fsi_aspeed_apb2opb_realize(DeviceState *dev, Error **errp)
>> +{
>> +    SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
>> +    AspeedAPB2OPBState *s = ASPEED_APB2OPB(dev);
>> +    int i;
>> +
>> +    sysbus_init_irq(sbd, &s->irq);
>> +
>> +    memory_region_init_io(&s->iomem, OBJECT(s), &aspeed_apb2opb_ops, s,
>> +                          TYPE_ASPEED_APB2OPB, 0x1000);
>> +    sysbus_init_mmio(sbd, &s->iomem);
>> +
>> +    for (i = 0; i < ASPEED_FSI_NUM; i++) {
>> +        if (!qdev_realize_and_unref(DEVICE(&s->fsi[i]), 
>> BUS(&s->opb[i]),
>
>
> s->fsi[i] is not allocated. We should use qdev_realize instead.

I am not sure I understood this. FSIMasterState fsi[ASPEED_FSI_NUM]; is 
embedded inside structure AspeedAPB2OPBState so it must be allocated, right?

Thanks for the review.

Regards,

Ninad

>
>
> Thanks,
>
> C.
>
>
>
>> +                errp)) {
>> +            return;
>> +        }
>> +
>> +        memory_region_add_subregion(&s->opb[i].mr, 0x80000000,
>> +                &s->fsi[i].iomem);
>> +
>> +        /* OPB2FSI region */
>> +        /*
>> +         * Avoid endianness issues by mapping each slave's memory 
>> region
>> +         * directly. Manually bridging multiple address-spaces 
>> causes endian
>> +         * swapping headaches as memory_region_dispatch_read() and
>> +         * memory_region_dispatch_write() correct the endianness 
>> based on the
>> +         * target machine endianness and not relative to the device 
>> endianness
>> +         * on either side of the bridge.
>> +         */
>> +        /*
>> +         * XXX: This is a bit hairy and will need to be fixed when I 
>> sort out
>> +         * the bus/slave relationship and any changes to the CFAM 
>> modelling
>> +         * (multiple slaves, LBUS)
>> +         */
>> +        memory_region_add_subregion(&s->opb[i].mr, 0xa0000000,
>> +                &s->fsi[i].opb2fsi);
>> +    }
>> +}
>> +
>> +static void fsi_aspeed_apb2opb_reset(DeviceState *dev)
>> +{
>> +    AspeedAPB2OPBState *s = ASPEED_APB2OPB(dev);
>> +
>> +    memcpy(s->regs, aspeed_apb2opb_reset, ASPEED_APB2OPB_NR_REGS);
>> +}
>> +
>> +static void fsi_aspeed_apb2opb_class_init(ObjectClass *klass, void 
>> *data)
>> +{
>> +    DeviceClass *dc = DEVICE_CLASS(klass);
>> +
>> +    dc->desc = "ASPEED APB2OPB Bridge";
>> +    dc->realize = fsi_aspeed_apb2opb_realize;
>> +    dc->reset = fsi_aspeed_apb2opb_reset;
>> +}
>> +
>> +static const TypeInfo aspeed_apb2opb_info = {
>> +    .name = TYPE_ASPEED_APB2OPB,
>> +    .parent = TYPE_SYS_BUS_DEVICE,
>> +    .instance_init = fsi_aspeed_apb2opb_init,
>> +    .instance_size = sizeof(AspeedAPB2OPBState),
>> +    .class_init = fsi_aspeed_apb2opb_class_init,
>> +};
>> +
>> +static void aspeed_apb2opb_register_types(void)
>> +{
>> +    type_register_static(&aspeed_apb2opb_info);
>> +}
>> +
>> +type_init(aspeed_apb2opb_register_types);
>> diff --git a/hw/arm/Kconfig b/hw/arm/Kconfig
>> index 3ada335a24..0a3bc712a4 100644
>> --- a/hw/arm/Kconfig
>> +++ b/hw/arm/Kconfig
>> @@ -559,6 +559,7 @@ config ASPEED_SOC
>>       select LED
>>       select PMBUS
>>       select MAX31785
>> +    select FSI_APB2OPB_ASPEED
>>     config MPS2
>>       bool
>> diff --git a/hw/fsi/Kconfig b/hw/fsi/Kconfig
>> index 9755baa8cc..9e92b07930 100644
>> --- a/hw/fsi/Kconfig
>> +++ b/hw/fsi/Kconfig
>> @@ -1,3 +1,7 @@
>> +config FSI_APB2OPB_ASPEED
>> +    bool
>> +    select FSI_OPB
>> +
>>   config FSI_OPB
>>       bool
>>       select FSI_CFAM
>> diff --git a/hw/fsi/meson.build b/hw/fsi/meson.build
>> index 038c4468ee..d0910627f9 100644
>> --- a/hw/fsi/meson.build
>> +++ b/hw/fsi/meson.build
>> @@ -2,3 +2,4 @@ system_ss.add(when: 'CONFIG_FSI_LBUS', if_true: 
>> files('lbus.c'))
>>   system_ss.add(when: 'CONFIG_FSI_CFAM', if_true: files('cfam.c'))
>>   system_ss.add(when: 'CONFIG_FSI', if_true: 
>> files('fsi.c','fsi-master.c','fsi-slave.c'))
>>   system_ss.add(when: 'CONFIG_FSI_OPB', if_true: files('opb.c'))
>> +system_ss.add(when: 'CONFIG_FSI_APB2OPB_ASPEED', if_true: 
>> files('aspeed-apb2opb.c'))
>> diff --git a/hw/fsi/trace-events b/hw/fsi/trace-events
>> index 89d8cd62c8..3af4755995 100644
>> --- a/hw/fsi/trace-events
>> +++ b/hw/fsi/trace-events
>> @@ -9,3 +9,5 @@ fsi_slave_read(uint64_t addr, uint32_t size) "@0x%" 
>> PRIx64 " size=%d"
>>   fsi_slave_write(uint64_t addr, uint32_t size, uint64_t data) "@0x%" 
>> PRIx64 " size=%d value=0x%"PRIx64
>>   fsi_master_read(uint64_t addr, uint32_t size) "@0x%" PRIx64 " size=%d"
>>   fsi_master_write(uint64_t addr, uint32_t size, uint64_t data) 
>> "@0x%" PRIx64 " size=%d value=0x%"PRIx64
>> +fsi_aspeed_apb2opb_read(uint64_t addr, uint32_t size) "@0x%" PRIx64 
>> " size=%d"
>> +fsi_aspeed_apb2opb_write(uint64_t addr, uint32_t size, uint64_t 
>> data) "@0x%" PRIx64 " size=%d value=0x%"PRIx64
>
Cédric Le Goater Jan. 9, 2024, 7:38 a.m. UTC | #3 
Hello Ninad,

>>> +static void fsi_aspeed_apb2opb_realize(DeviceState *dev, Error **errp)
>>> +{
>>> +    SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
>>> +    AspeedAPB2OPBState *s = ASPEED_APB2OPB(dev);
>>> +    int i;
>>> +
>>> +    sysbus_init_irq(sbd, &s->irq);
>>> +
>>> +    memory_region_init_io(&s->iomem, OBJECT(s), &aspeed_apb2opb_ops, s,
>>> +                          TYPE_ASPEED_APB2OPB, 0x1000);
>>> +    sysbus_init_mmio(sbd, &s->iomem);
>>> +
>>> +    for (i = 0; i < ASPEED_FSI_NUM; i++) {
>>> +        if (!qdev_realize_and_unref(DEVICE(&s->fsi[i]), BUS(&s->opb[i]),
>>
>>
>> s->fsi[i] is not allocated. We should use qdev_realize instead.
> 
> I am not sure I understood this. FSIMasterState fsi[ASPEED_FSI_NUM]; is 
> inside structure AspeedAPB2OPBState so it must be allocated, right?

See the documentation :

   https://www.qemu.org/docs/master/devel/qdev-api.html#c.qdev_realize_and_unref

Thanks,

C.
Ninad Palsule Jan. 9, 2024, 8:30 p.m. UTC | #4 
Hello Cedric,


>>>> +    for (i = 0; i < ASPEED_FSI_NUM; i++) {
>>>> +        if (!qdev_realize_and_unref(DEVICE(&s->fsi[i]), 
>>>> BUS(&s->opb[i]),
>>>
>>>
>>> s->fsi[i] is not allocated. We should use qdev_realize instead.
>>
>> I am not sure I understood this. FSIMasterState fsi[ASPEED_FSI_NUM]; 
>> is inside structure AspeedAPB2OPBState so it must be allocated, right?
>
> See the documentation :
>
> https://www.qemu.org/docs/master/devel/qdev-api.html#c.qdev_realize_and_unref

Fixed it. Thanks for the review.

Regards,

Ninad
diff mbox series

Patch

diff --git a/include/hw/fsi/aspeed-apb2opb.h b/include/hw/fsi/aspeed-apb2opb.h
new file mode 100644
index 0000000000..c51fbeda9f
--- /dev/null
+++ b/include/hw/fsi/aspeed-apb2opb.h
@@ -0,0 +1,34 @@ 
+/*
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ * Copyright (C) 2023 IBM Corp.
+ *
+ * ASPEED APB2OPB Bridge
+ */
+#ifndef FSI_ASPEED_APB2OPB_H
+#define FSI_ASPEED_APB2OPB_H
+
+#include "hw/sysbus.h"
+#include "hw/fsi/opb.h"
+
+#define TYPE_ASPEED_APB2OPB "aspeed.apb2opb"
+OBJECT_DECLARE_SIMPLE_TYPE(AspeedAPB2OPBState, ASPEED_APB2OPB)
+
+#define ASPEED_APB2OPB_NR_REGS ((0xe8 >> 2) + 1)
+
+#define ASPEED_FSI_NUM 2
+
+typedef struct AspeedAPB2OPBState {
+    /*< private >*/
+    SysBusDevice parent_obj;
+
+    /*< public >*/
+    MemoryRegion iomem;
+
+    uint32_t regs[ASPEED_APB2OPB_NR_REGS];
+    qemu_irq irq;
+
+    OPBus opb[ASPEED_FSI_NUM];
+    FSIMasterState fsi[ASPEED_FSI_NUM];
+} AspeedAPB2OPBState;
+
+#endif /* FSI_ASPEED_APB2OPB_H */
diff --git a/hw/fsi/aspeed-apb2opb.c b/hw/fsi/aspeed-apb2opb.c
new file mode 100644
index 0000000000..70b3fe2587
--- /dev/null
+++ b/hw/fsi/aspeed-apb2opb.c
@@ -0,0 +1,316 @@ 
+/*
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ * Copyright (C) 2023 IBM Corp.
+ *
+ * ASPEED APB-OPB FSI interface
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/log.h"
+#include "qom/object.h"
+#include "qapi/error.h"
+#include "trace.h"
+
+#include "hw/fsi/aspeed-apb2opb.h"
+#include "hw/qdev-core.h"
+
+#define TO_REG(x) (x >> 2)
+
+#define APB2OPB_VERSION                    TO_REG(0x00)
+#define APB2OPB_TRIGGER                    TO_REG(0x04)
+
+#define APB2OPB_CONTROL                    TO_REG(0x08)
+#define   APB2OPB_CONTROL_OFF              BE_GENMASK(31, 13)
+
+#define APB2OPB_OPB2FSI                    TO_REG(0x0c)
+#define   APB2OPB_OPB2FSI_OFF              BE_GENMASK(31, 22)
+
+#define APB2OPB_OPB0_SEL                   TO_REG(0x10)
+#define APB2OPB_OPB1_SEL                   TO_REG(0x28)
+#define   APB2OPB_OPB_SEL_EN               BIT(0)
+
+#define APB2OPB_OPB0_MODE                  TO_REG(0x14)
+#define APB2OPB_OPB1_MODE                  TO_REG(0x2c)
+#define   APB2OPB_OPB_MODE_RD              BIT(0)
+
+#define APB2OPB_OPB0_XFER                  TO_REG(0x18)
+#define APB2OPB_OPB1_XFER                  TO_REG(0x30)
+#define   APB2OPB_OPB_XFER_FULL            BIT(1)
+#define   APB2OPB_OPB_XFER_HALF            BIT(0)
+
+#define APB2OPB_OPB0_ADDR                  TO_REG(0x1c)
+#define APB2OPB_OPB0_WRITE_DATA            TO_REG(0x20)
+
+#define APB2OPB_OPB1_ADDR                  TO_REG(0x34)
+#define APB2OPB_OPB1_WRITE_DATA                  TO_REG(0x38)
+
+#define APB2OPB_IRQ_STS                    TO_REG(0x48)
+#define   APB2OPB_IRQ_STS_OPB1_TX_ACK      BIT(17)
+#define   APB2OPB_IRQ_STS_OPB0_TX_ACK      BIT(16)
+
+#define APB2OPB_OPB0_WRITE_WORD_ENDIAN     TO_REG(0x4c)
+#define   APB2OPB_OPB0_WRITE_WORD_ENDIAN_BE 0x0011101b
+#define APB2OPB_OPB0_WRITE_BYTE_ENDIAN     TO_REG(0x50)
+#define   APB2OPB_OPB0_WRITE_BYTE_ENDIAN_BE 0x0c330f3f
+#define APB2OPB_OPB1_WRITE_WORD_ENDIAN     TO_REG(0x54)
+#define APB2OPB_OPB1_WRITE_BYTE_ENDIAN     TO_REG(0x58)
+#define APB2OPB_OPB0_READ_BYTE_ENDIAN      TO_REG(0x5c)
+#define APB2OPB_OPB1_READ_BYTE_ENDIAN      TO_REG(0x60)
+#define   APB2OPB_OPB0_READ_WORD_ENDIAN_BE  0x00030b1b
+
+#define APB2OPB_OPB0_READ_DATA         TO_REG(0x84)
+#define APB2OPB_OPB1_READ_DATA         TO_REG(0x90)
+
+/*
+ * The following magic values came from AST2600 data sheet
+ * The register values are defined under section "FSI controller"
+ * as initial values.
+ */
+static const uint32_t aspeed_apb2opb_reset[ASPEED_APB2OPB_NR_REGS] = {
+     [APB2OPB_VERSION]                = 0x000000a1,
+     [APB2OPB_OPB0_WRITE_WORD_ENDIAN] = 0x0044eee4,
+     [APB2OPB_OPB0_WRITE_BYTE_ENDIAN] = 0x0055aaff,
+     [APB2OPB_OPB1_WRITE_WORD_ENDIAN] = 0x00117717,
+     [APB2OPB_OPB1_WRITE_BYTE_ENDIAN] = 0xffaa5500,
+     [APB2OPB_OPB0_READ_BYTE_ENDIAN]  = 0x0044eee4,
+     [APB2OPB_OPB1_READ_BYTE_ENDIAN]  = 0x00117717
+};
+
+static void fsi_opb_fsi_master_address(OPBus *opb, FSIMasterState* fsi,
+                                       hwaddr addr)
+{
+    memory_region_transaction_begin();
+    memory_region_set_address(&fsi->iomem, addr);
+    memory_region_transaction_commit();
+}
+
+static void fsi_opb_opb2fsi_address(OPBus *opb, FSIMasterState* fsi,
+                                    hwaddr addr)
+{
+    memory_region_transaction_begin();
+    memory_region_set_address(&fsi->opb2fsi, addr);
+    memory_region_transaction_commit();
+}
+
+static uint64_t fsi_aspeed_apb2opb_read(void *opaque, hwaddr addr,
+                                        unsigned size)
+{
+    AspeedAPB2OPBState *s = ASPEED_APB2OPB(opaque);
+    unsigned int reg = TO_REG(addr);
+
+    trace_fsi_aspeed_apb2opb_read(addr, size);
+
+    if (reg >= ASPEED_APB2OPB_NR_REGS) {
+        qemu_log_mask(LOG_GUEST_ERROR,
+                      "%s: Out of bounds read: 0x%"HWADDR_PRIx" for %u\n",
+                      __func__, addr, size);
+        return 0;
+    }
+
+    return s->regs[reg];
+}
+
+static void fsi_aspeed_apb2opb_write(void *opaque, hwaddr addr, uint64_t data,
+                                     unsigned size)
+{
+    AspeedAPB2OPBState *s = ASPEED_APB2OPB(opaque);
+    unsigned int reg = TO_REG(addr);
+
+    trace_fsi_aspeed_apb2opb_write(addr, size, data);
+
+    if (reg >= ASPEED_APB2OPB_NR_REGS) {
+        qemu_log_mask(LOG_GUEST_ERROR,
+                      "%s: Out of bounds write: %"HWADDR_PRIx" for %u\n",
+                      __func__, addr, size);
+        return;
+    }
+
+    switch (reg) {
+    case APB2OPB_CONTROL:
+        fsi_opb_fsi_master_address(&s->opb[0], &s->fsi[0],
+                data & APB2OPB_CONTROL_OFF);
+        break;
+    case APB2OPB_OPB2FSI:
+        fsi_opb_opb2fsi_address(&s->opb[0], &s->fsi[0],
+                data & APB2OPB_OPB2FSI_OFF);
+        break;
+    case APB2OPB_OPB0_WRITE_WORD_ENDIAN:
+        if (data != APB2OPB_OPB0_WRITE_WORD_ENDIAN_BE) {
+            qemu_log_mask(LOG_GUEST_ERROR,
+                          "%s: Bridge needs to be driven as BE (0x%x)\n",
+                          __func__, APB2OPB_OPB0_WRITE_WORD_ENDIAN_BE);
+        }
+        break;
+    case APB2OPB_OPB0_WRITE_BYTE_ENDIAN:
+        if (data != APB2OPB_OPB0_WRITE_BYTE_ENDIAN_BE) {
+            qemu_log_mask(LOG_GUEST_ERROR,
+                          "%s: Bridge needs to be driven as BE (0x%x)\n",
+                          __func__, APB2OPB_OPB0_WRITE_BYTE_ENDIAN_BE);
+        }
+        break;
+    case APB2OPB_OPB0_READ_BYTE_ENDIAN:
+        if (data != APB2OPB_OPB0_READ_WORD_ENDIAN_BE) {
+            qemu_log_mask(LOG_GUEST_ERROR,
+                          "%s: Bridge needs to be driven as BE (0x%x)\n",
+                          __func__, APB2OPB_OPB0_READ_WORD_ENDIAN_BE);
+        }
+        break;
+    case APB2OPB_TRIGGER:
+    {
+        uint32_t opb, op_mode, op_size, op_addr, op_data;
+        MemTxResult result;
+        bool is_write;
+        int index;
+        AddressSpace *as;
+
+        assert((s->regs[APB2OPB_OPB0_SEL] & APB2OPB_OPB_SEL_EN) ^
+               (s->regs[APB2OPB_OPB1_SEL] & APB2OPB_OPB_SEL_EN));
+
+        if (s->regs[APB2OPB_OPB0_SEL] & APB2OPB_OPB_SEL_EN) {
+            opb = 0;
+            op_mode = s->regs[APB2OPB_OPB0_MODE];
+            op_size = s->regs[APB2OPB_OPB0_XFER];
+            op_addr = s->regs[APB2OPB_OPB0_ADDR];
+            op_data = s->regs[APB2OPB_OPB0_WRITE_DATA];
+        } else if (s->regs[APB2OPB_OPB1_SEL] & APB2OPB_OPB_SEL_EN) {
+            opb = 1;
+            op_mode = s->regs[APB2OPB_OPB1_MODE];
+            op_size = s->regs[APB2OPB_OPB1_XFER];
+            op_addr = s->regs[APB2OPB_OPB1_ADDR];
+            op_data = s->regs[APB2OPB_OPB1_WRITE_DATA];
+        } else {
+            qemu_log_mask(LOG_GUEST_ERROR,
+                          "%s: Invalid operation: 0x%"HWADDR_PRIx" for %u\n",
+                          __func__, addr, size);
+            return;
+        }
+
+        if (op_size & ~(APB2OPB_OPB_XFER_HALF | APB2OPB_OPB_XFER_FULL)) {
+            qemu_log_mask(LOG_GUEST_ERROR,
+                          "OPB transaction failed: Unrecognized access width: %d\n",
+                          op_size);
+            return;
+        }
+
+        op_size += 1;
+        is_write = !(op_mode & APB2OPB_OPB_MODE_RD);
+        index = opb ? APB2OPB_OPB1_READ_DATA : APB2OPB_OPB0_READ_DATA;
+        as = &s->opb[opb].as;
+
+        result = address_space_rw(as, op_addr, MEMTXATTRS_UNSPECIFIED,
+                                  &op_data, op_size, is_write);
+        if (result != MEMTX_OK) {
+            qemu_log_mask(LOG_GUEST_ERROR, "%s: OPB %s failed @%08x\n",
+                          __func__, is_write ? "write" : "read", op_addr);
+            return;
+        }
+
+        if (!is_write) {
+            s->regs[index] = op_data;
+        }
+
+        s->regs[APB2OPB_IRQ_STS] |= opb ? APB2OPB_IRQ_STS_OPB1_TX_ACK
+            : APB2OPB_IRQ_STS_OPB0_TX_ACK;
+        break;
+    }
+    }
+
+    s->regs[reg] = data;
+}
+
+static const struct MemoryRegionOps aspeed_apb2opb_ops = {
+    .read = fsi_aspeed_apb2opb_read,
+    .write = fsi_aspeed_apb2opb_write,
+    .valid.max_access_size = 4,
+    .valid.min_access_size = 4,
+    .impl.max_access_size = 4,
+    .impl.min_access_size = 4,
+    .endianness = DEVICE_LITTLE_ENDIAN,
+};
+
+static void fsi_aspeed_apb2opb_init(Object *o)
+{
+    AspeedAPB2OPBState *s = ASPEED_APB2OPB(o);
+    int i;
+
+    for (i = 0; i < ASPEED_FSI_NUM; i++) {
+        qbus_init(&s->opb[i], sizeof(s->opb[i]), TYPE_OP_BUS, DEVICE(s),
+                  NULL);
+    }
+
+    for (i = 0; i < ASPEED_FSI_NUM; i++) {
+        object_initialize_child(o, "fsi-master[*]", &s->fsi[i],
+                                TYPE_FSI_MASTER);
+    }
+}
+
+static void fsi_aspeed_apb2opb_realize(DeviceState *dev, Error **errp)
+{
+    SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
+    AspeedAPB2OPBState *s = ASPEED_APB2OPB(dev);
+    int i;
+
+    sysbus_init_irq(sbd, &s->irq);
+
+    memory_region_init_io(&s->iomem, OBJECT(s), &aspeed_apb2opb_ops, s,
+                          TYPE_ASPEED_APB2OPB, 0x1000);
+    sysbus_init_mmio(sbd, &s->iomem);
+
+    for (i = 0; i < ASPEED_FSI_NUM; i++) {
+        if (!qdev_realize_and_unref(DEVICE(&s->fsi[i]), BUS(&s->opb[i]),
+                errp)) {
+            return;
+        }
+
+        memory_region_add_subregion(&s->opb[i].mr, 0x80000000,
+                &s->fsi[i].iomem);
+
+        /* OPB2FSI region */
+        /*
+         * Avoid endianness issues by mapping each slave's memory region
+         * directly. Manually bridging multiple address-spaces causes endian
+         * swapping headaches as memory_region_dispatch_read() and
+         * memory_region_dispatch_write() correct the endianness based on the
+         * target machine endianness and not relative to the device endianness
+         * on either side of the bridge.
+         */
+        /*
+         * XXX: This is a bit hairy and will need to be fixed when I sort out
+         * the bus/slave relationship and any changes to the CFAM modelling
+         * (multiple slaves, LBUS)
+         */
+        memory_region_add_subregion(&s->opb[i].mr, 0xa0000000,
+                &s->fsi[i].opb2fsi);
+    }
+}
+
+static void fsi_aspeed_apb2opb_reset(DeviceState *dev)
+{
+    AspeedAPB2OPBState *s = ASPEED_APB2OPB(dev);
+
+    memcpy(s->regs, aspeed_apb2opb_reset, ASPEED_APB2OPB_NR_REGS);
+}
+
+static void fsi_aspeed_apb2opb_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+
+    dc->desc = "ASPEED APB2OPB Bridge";
+    dc->realize = fsi_aspeed_apb2opb_realize;
+    dc->reset = fsi_aspeed_apb2opb_reset;
+}
+
+static const TypeInfo aspeed_apb2opb_info = {
+    .name = TYPE_ASPEED_APB2OPB,
+    .parent = TYPE_SYS_BUS_DEVICE,
+    .instance_init = fsi_aspeed_apb2opb_init,
+    .instance_size = sizeof(AspeedAPB2OPBState),
+    .class_init = fsi_aspeed_apb2opb_class_init,
+};
+
+static void aspeed_apb2opb_register_types(void)
+{
+    type_register_static(&aspeed_apb2opb_info);
+}
+
+type_init(aspeed_apb2opb_register_types);
diff --git a/hw/arm/Kconfig b/hw/arm/Kconfig
index 3ada335a24..0a3bc712a4 100644
--- a/hw/arm/Kconfig
+++ b/hw/arm/Kconfig
@@ -559,6 +559,7 @@  config ASPEED_SOC
     select LED
     select PMBUS
     select MAX31785
+    select FSI_APB2OPB_ASPEED
 
 config MPS2
     bool
diff --git a/hw/fsi/Kconfig b/hw/fsi/Kconfig
index 9755baa8cc..9e92b07930 100644
--- a/hw/fsi/Kconfig
+++ b/hw/fsi/Kconfig
@@ -1,3 +1,7 @@ 
+config FSI_APB2OPB_ASPEED
+    bool
+    select FSI_OPB
+
 config FSI_OPB
     bool
     select FSI_CFAM
diff --git a/hw/fsi/meson.build b/hw/fsi/meson.build
index 038c4468ee..d0910627f9 100644
--- a/hw/fsi/meson.build
+++ b/hw/fsi/meson.build
@@ -2,3 +2,4 @@  system_ss.add(when: 'CONFIG_FSI_LBUS', if_true: files('lbus.c'))
 system_ss.add(when: 'CONFIG_FSI_CFAM', if_true: files('cfam.c'))
 system_ss.add(when: 'CONFIG_FSI', if_true: files('fsi.c','fsi-master.c','fsi-slave.c'))
 system_ss.add(when: 'CONFIG_FSI_OPB', if_true: files('opb.c'))
+system_ss.add(when: 'CONFIG_FSI_APB2OPB_ASPEED', if_true: files('aspeed-apb2opb.c'))
diff --git a/hw/fsi/trace-events b/hw/fsi/trace-events
index 89d8cd62c8..3af4755995 100644
--- a/hw/fsi/trace-events
+++ b/hw/fsi/trace-events
@@ -9,3 +9,5 @@  fsi_slave_read(uint64_t addr, uint32_t size) "@0x%" PRIx64 " size=%d"
 fsi_slave_write(uint64_t addr, uint32_t size, uint64_t data) "@0x%" PRIx64 " size=%d value=0x%"PRIx64
 fsi_master_read(uint64_t addr, uint32_t size) "@0x%" PRIx64 " size=%d"
 fsi_master_write(uint64_t addr, uint32_t size, uint64_t data) "@0x%" PRIx64 " size=%d value=0x%"PRIx64
+fsi_aspeed_apb2opb_read(uint64_t addr, uint32_t size) "@0x%" PRIx64 " size=%d"
+fsi_aspeed_apb2opb_write(uint64_t addr, uint32_t size, uint64_t data) "@0x%" PRIx64 " size=%d value=0x%"PRIx64