Re: [PATCH v11 04/11] hw/fsi: Introduce IBM's fsi-slave model

[Cédric Le Goater]

On 1/26/24 04:40, Ninad Palsule wrote:
> This is a part of patchset where IBM's Flexible Service Interface is
> introduced.
>
> The FSI slave: The slave is the terminal point of the FSI bus for
> FSI symbols addressed to it. Slaves can be cascaded off of one
> another. The slave's configuration registers appear in address space
> of the CFAM to which it is attached.
>
> Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
> Signed-off-by: Cédric Le Goater <clg@kaod.org>
> Signed-off-by: Ninad Palsule <ninad@linux.ibm.com>
> ---
>   include/hw/fsi/fsi.h | 19 ++++++++++
>   hw/fsi/fsi.c         | 87 +++++++++++++++++++++++++++++++++++++++++++-
>   hw/fsi/trace-events  |  2 +
>   3 files changed, 106 insertions(+), 2 deletions(-)
>
> diff --git a/include/hw/fsi/fsi.h b/include/hw/fsi/fsi.h
> index 50e8f5c888..6e11747dd5 100644
> --- a/include/hw/fsi/fsi.h
> +++ b/include/hw/fsi/fsi.h
> @@ -7,7 +7,14 @@
>   #ifndef FSI_FSI_H
>   #define FSI_FSI_H
>   
> +#include "exec/memory.h"
>   #include "hw/qdev-core.h"
> +#include "hw/fsi/lbus.h"
> +#include "qemu/bitops.h"
> +
> +/* Bitwise operations at the word level. */
> +#define BE_BIT(x)           BIT(31 - (x))
> +#define BE_GENMASK(hb, lb)  MAKE_64BIT_MASK((lb), ((hb) - (lb) + 1))
>   
>   #define TYPE_FSI_BUS "fsi.bus"
>   OBJECT_DECLARE_SIMPLE_TYPE(FSIBus, FSI_BUS)
> @@ -16,4 +23,16 @@ typedef struct FSIBus {
>       BusState bus;
>   } FSIBus;
>   
> +#define TYPE_FSI_SLAVE "fsi.slave"
> +OBJECT_DECLARE_SIMPLE_TYPE(FSISlaveState, FSI_SLAVE)
> +
> +#define FSI_SLAVE_CONTROL_NR_REGS ((0x40 >> 2) + 1)
> +
> +typedef struct FSISlaveState {
> +    DeviceState parent;
> +
> +    MemoryRegion iomem;
> +    uint32_t regs[FSI_SLAVE_CONTROL_NR_REGS];
> +} FSISlaveState;
> +
>   #endif /* FSI_FSI_H */
> diff --git a/hw/fsi/fsi.c b/hw/fsi/fsi.c
> index 60cb03f7a2..528323d9cf 100644
> --- a/hw/fsi/fsi.c
> +++ b/hw/fsi/fsi.c
> @@ -5,18 +5,101 @@
>    * IBM Flexible Service Interface
>    */
>   #include "qemu/osdep.h"
> +#include "qapi/error.h"
> +#include "qemu/log.h"
> +#include "trace.h"
>   
>   #include "hw/fsi/fsi.h"
>   
> +#define TO_REG(x)                               ((x) >> 2)
> +
>   static const TypeInfo fsi_bus_info = {
>       .name = TYPE_FSI_BUS,
>       .parent = TYPE_BUS,
>       .instance_size = sizeof(FSIBus),
>   };
>   
> -static void fsi_bus_register_types(void)
> +static uint64_t fsi_slave_read(void *opaque, hwaddr addr, unsigned size)
> +{
> +    FSISlaveState *s = FSI_SLAVE(opaque);
> +    int reg = TO_REG(addr);
> +
> +    trace_fsi_slave_read(addr, size);
> +
> +    if (reg >= FSI_SLAVE_CONTROL_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_slave_write(void *opaque, hwaddr addr, uint64_t data,
> +                                 unsigned size)
> +{
> +    FSISlaveState *s = FSI_SLAVE(opaque);
> +    int reg = TO_REG(addr);
> +
> +    trace_fsi_slave_write(addr, size, data);
> +
> +    if (reg >= FSI_SLAVE_CONTROL_NR_REGS) {
> +        qemu_log_mask(LOG_GUEST_ERROR,
> +                      "%s: Out of bounds write: 0x%"HWADDR_PRIx" for %u\n",
> +                      __func__, addr, size);
> +        return;
> +    }
> +
> +    s->regs[reg] = data;
> +}
> +
> +static const struct MemoryRegionOps fsi_slave_ops = {
> +    .read = fsi_slave_read,
> +    .write = fsi_slave_write,
> +    .endianness = DEVICE_BIG_ENDIAN,
> +};
> +
> +static void fsi_slave_reset(DeviceState *dev)
> +{
> +    FSISlaveState *s = FSI_SLAVE(dev);
> +    int i;
> +
> +    /* Initialize registers */
> +    for (i = 0; i < FSI_SLAVE_CONTROL_NR_REGS; i++) {
> +        s->regs[i] = 0;
> +    }

memset would be better.

with that fixed,


Reviewed-by: Cédric Le Goater <clg@kaod.org>

Thanks,

C.


> +}
> +
> +static void fsi_slave_init(Object *o)
> +{
> +    FSISlaveState *s = FSI_SLAVE(o);
> +
> +    memory_region_init_io(&s->iomem, OBJECT(s), &fsi_slave_ops,
> +                          s, TYPE_FSI_SLAVE, 0x400);
> +}
> +
> +static void fsi_slave_class_init(ObjectClass *klass, void *data)
> +{
> +    DeviceClass *dc = DEVICE_CLASS(klass);
> +
> +    dc->bus_type = TYPE_FSI_BUS;
> +    dc->desc = "FSI Slave";
> +    dc->reset = fsi_slave_reset;
> +}
> +
> +static const TypeInfo fsi_slave_info = {
> +    .name = TYPE_FSI_SLAVE,
> +    .parent = TYPE_DEVICE,
> +    .instance_init = fsi_slave_init,
> +    .instance_size = sizeof(FSISlaveState),
> +    .class_init = fsi_slave_class_init,
> +};
> +
> +static void fsi_register_types(void)
>   {
>       type_register_static(&fsi_bus_info);
> +    type_register_static(&fsi_slave_info);
>   }
>   
> -type_init(fsi_bus_register_types);
> +type_init(fsi_register_types);
> diff --git a/hw/fsi/trace-events b/hw/fsi/trace-events
> index c5753e2791..8f29adb7df 100644
> --- a/hw/fsi/trace-events
> +++ b/hw/fsi/trace-events
> @@ -1,2 +1,4 @@
>   fsi_scratchpad_read(uint64_t addr, uint32_t size) "@0x%" PRIx64 " size=%d"
>   fsi_scratchpad_write(uint64_t addr, uint32_t size, uint64_t data) "@0x%" PRIx64 " 
> size=%d value=0x%"PRIx64
> +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