Re: [PATCH v6 01/10] hw/fsi: Introduce IBM's Local bus

["Philippe Mathieu-Daudé" <philmd@linaro.org>]

Hi Ninad and Andrew,

On 21/10/23 23:17, Ninad Palsule wrote:
> This is a part of patchset where IBM's Flexible Service Interface is
> introduced.
> 
> The LBUS is modelled to maintain the qdev bus hierarchy and to take
> advantage of the object model to automatically generate the CFAM
> configuration block. The configuration block presents engines in the
> order they are attached to the CFAM's LBUS. Engine implementations
> should subclass the LBusDevice and set the 'config' member of
> LBusDeviceClass to match the engine's type.
> 
> Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
> Signed-off-by: Ninad Palsule <ninad@linux.ibm.com>
> ---
> v2:
> - Incorporated Joel's review comments.
> v5:
> - Incorporated review comments by Cedric.
> v6:
> - Incorporated review comments by Cedric & Daniel.
> ---
>   include/hw/fsi/lbus.h | 43 ++++++++++++++++++++++++
>   hw/fsi/lbus.c         | 76 +++++++++++++++++++++++++++++++++++++++++++
>   hw/Kconfig            |  1 +
>   hw/fsi/Kconfig        |  2 ++
>   hw/fsi/meson.build    |  1 +
>   hw/meson.build        |  1 +
>   6 files changed, 124 insertions(+)
>   create mode 100644 include/hw/fsi/lbus.h
>   create mode 100644 hw/fsi/lbus.c
>   create mode 100644 hw/fsi/Kconfig
>   create mode 100644 hw/fsi/meson.build


> +#define TYPE_FSI_LBUS_DEVICE "fsi.lbus.device"
> +OBJECT_DECLARE_TYPE(FSILBusDevice, FSILBusDeviceClass, FSI_LBUS_DEVICE)
> +
> +#define FSI_LBUS_MEM_REGION_SIZE  (2 * 1024 * 1024)
> +#define FSI_LBUSDEV_IOMEM_SIZE    0x400
> +
> +typedef struct FSILBusDevice {
> +    DeviceState parent;
> +
> +    MemoryRegion iomem;
> +    uint32_t address;

[1] 32-bit address,

> +} FSILBusDevice;
> +


> diff --git a/hw/fsi/lbus.c b/hw/fsi/lbus.c
> new file mode 100644
> index 0000000000..50d926dbe2
> --- /dev/null
> +++ b/hw/fsi/lbus.c
> @@ -0,0 +1,76 @@
> +/*
> + * SPDX-License-Identifier: GPL-2.0-or-later
> + * Copyright (C) 2023 IBM Corp.
> + *
> + * IBM Local bus where FSI slaves are connected
> + */
> +
> +#include "qemu/osdep.h"
> +#include "qapi/error.h"
> +#include "hw/fsi/lbus.h"
> +
> +#include "hw/qdev-properties.h"
> +
> +static void lbus_init(Object *o)
> +{
> +    FSILBus *lbus = FSI_LBUS(o);
> +
> +    memory_region_init(&lbus->mr, OBJECT(lbus), TYPE_FSI_LBUS,
> +                       FSI_LBUS_MEM_REGION_SIZE - FSI_LBUSDEV_IOMEM_SIZE);
> +}
> +
> +static const TypeInfo lbus_info = {
> +    .name = TYPE_FSI_LBUS,
> +    .parent = TYPE_BUS,
> +    .instance_init = lbus_init,
> +    .instance_size = sizeof(FSILBus),
> +};
> +
> +static Property lbus_device_props[] = {
> +    DEFINE_PROP_UINT32("address", FSILBusDevice, address, 0),

[2] 32-bit address,

> +    DEFINE_PROP_END_OF_LIST(),
> +};
> +
> +DeviceState *lbus_create_device(FSILBus *bus, const char *type, uint32_t addr)
> +{
> +    DeviceState *ds;
> +    BusState *state = BUS(bus);
> +    FSILBusDevice *dev;
> +
> +    ds = qdev_new(type);
> +    qdev_prop_set_uint8(ds, "address", addr);

[3] set 8-bit address but [1] and [2] declare as 32-bit.

> +    qdev_realize_and_unref(ds, state, &error_fatal);

If you pass the bus as argument here, ...

> +
> +    dev = FSI_LBUS_DEVICE(ds);
> +    memory_region_add_subregion(&bus->mr, dev->address,
> +                                &dev->iomem);
> +
> +    qdev_set_parent_bus(ds, state, &error_abort);

... why do you need that call here?

> +
> +    return ds;
> +}

Thanks,

Phil.