Re: [PATCH v4 01/10] hw/fsi: Introduce IBM's Local bus

[Cédric Le Goater]

On 9/9/23 00:28, 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: Cédric Le Goater <clg@kaod.org>
> Signed-off-by: Ninad Palsule <ninad@linux.ibm.com>
> ---
> v2:
> - Incorporated Joel's review comments.
> ---


It is nice to have the header files upfront.

  orderFile = /path/to/qemu/scripts/git.orderfile


>   hw/Kconfig            |  1 +
>   hw/fsi/Kconfig        |  2 +
>   hw/fsi/lbus.c         | 94 +++++++++++++++++++++++++++++++++++++++++++
>   hw/fsi/meson.build    |  1 +
>   hw/meson.build        |  1 +
>   include/hw/fsi/lbus.h | 48 ++++++++++++++++++++++
>   include/qemu/bitops.h |  6 +++
>   7 files changed, 153 insertions(+)
>   create mode 100644 hw/fsi/Kconfig
>   create mode 100644 hw/fsi/lbus.c
>   create mode 100644 hw/fsi/meson.build
>   create mode 100644 include/hw/fsi/lbus.h
>
> diff --git a/hw/Kconfig b/hw/Kconfig
> index ba62ff6417..2ccb73add5 100644
> --- a/hw/Kconfig
> +++ b/hw/Kconfig
> @@ -9,6 +9,7 @@ source core/Kconfig
>   source cxl/Kconfig
>   source display/Kconfig
>   source dma/Kconfig
> +source fsi/Kconfig
>   source gpio/Kconfig
>   source hyperv/Kconfig
>   source i2c/Kconfig
> diff --git a/hw/fsi/Kconfig b/hw/fsi/Kconfig
> new file mode 100644
> index 0000000000..687449e14e
> --- /dev/null
> +++ b/hw/fsi/Kconfig
> @@ -0,0 +1,2 @@
> +config LBUS
> +    bool
> diff --git a/hw/fsi/lbus.c b/hw/fsi/lbus.c
> new file mode 100644
> index 0000000000..afb26ef7ea
> --- /dev/null
> +++ b/hw/fsi/lbus.c
> @@ -0,0 +1,94 @@
> +/*
> + * 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 "qemu/log.h"
> +
> +#include "hw/fsi/lbus.h"
> +
> +#include "hw/qdev-properties.h"
> +
> +static void lbus_realize(BusState *bus, Error **errp)
> +{
> +    LBusNode *node;
> +    LBus *lbus = LBUS(bus);
> +
> +    memory_region_init(&lbus->mr, OBJECT(lbus), TYPE_LBUS,
> +                       (2 * 1024 * 1024) - 0x400);

please use some define

> +
> +    QLIST_FOREACH(node, &lbus->devices, next) {
> +        memory_region_add_subregion(&lbus->mr, node->ldev->address,
> +                                    &node->ldev->iomem);
> +    }
> +}
> +
> +static void lbus_init(Object *o)
> +{
> +}
> +

please remove if unused


> +static void lbus_class_init(ObjectClass *klass, void *data)
> +{
> +    BusClass *k = BUS_CLASS(klass);
> +    k->realize = lbus_realize;
> +}
> +
> +static const TypeInfo lbus_info = {
> +    .name = TYPE_LBUS,
> +    .parent = TYPE_BUS,
> +    .instance_init = lbus_init,
> +    .instance_size = sizeof(LBus),
> +    .class_init = lbus_class_init,
> +};
> +
> +static Property lbus_device_props[] = {
> +    DEFINE_PROP_UINT32("address", LBusDevice, address, 0),
> +    DEFINE_PROP_END_OF_LIST(),
> +};
> +
> +DeviceState *lbus_create_device(LBus *bus, const char *type, uint32_t addr)
> +{
> +    DeviceState *dev;
> +    LBusNode *node;
> +
> +    dev = qdev_new(type);
> +    qdev_prop_set_uint8(dev, "address", addr);
> +    qdev_realize_and_unref(dev, &bus->bus, &error_fatal);

 BUS(bus) ?

> +
> +    /* Move to post_load */
> +    node = g_malloc(sizeof(struct LBusNode));
> +    node->ldev = LBUS_DEVICE(dev);
> +    QLIST_INSERT_HEAD(&bus->devices, node, next);

This list looks useless to me.

> +    return dev;
> +}
> +
> +static void lbus_device_class_init(ObjectClass *klass, void *data)
> +{
> +    DeviceClass *dc = DEVICE_CLASS(klass);
> +
> +    dc->bus_type = TYPE_LBUS;
> +    device_class_set_props(dc, lbus_device_props);
> +}
> +
> +static const TypeInfo lbus_device_type_info = {
> +    .name = TYPE_LBUS_DEVICE,
> +    .parent = TYPE_DEVICE,
> +    .instance_size = sizeof(LBusDevice),
> +    .abstract = true,
> +    .class_init = lbus_device_class_init,
> +    .class_size = sizeof(LBusDeviceClass),
> +};
> +
> +static void lbus_register_types(void)
> +{
> +    type_register_static(&lbus_info);
> +    type_register_static(&lbus_device_type_info);
> +}
> +
> +type_init(lbus_register_types);
> diff --git a/hw/fsi/meson.build b/hw/fsi/meson.build
> new file mode 100644
> index 0000000000..e1007d5fea
> --- /dev/null
> +++ b/hw/fsi/meson.build
> @@ -0,0 +1 @@
> +system_ss.add(when: 'CONFIG_LBUS', if_true: files('lbus.c'))
> diff --git a/hw/meson.build b/hw/meson.build
> index c7ac7d3d75..6c71ee9cfa 100644
> --- a/hw/meson.build
> +++ b/hw/meson.build
> @@ -43,6 +43,7 @@ subdir('virtio')
>   subdir('watchdog')
>   subdir('xen')
>   subdir('xenpv')
> +subdir('fsi')
>   
>   subdir('alpha')
>   subdir('arm')
> diff --git a/include/hw/fsi/lbus.h b/include/hw/fsi/lbus.h
> new file mode 100644
> index 0000000000..fafc065178
> --- /dev/null
> +++ b/include/hw/fsi/lbus.h
> @@ -0,0 +1,48 @@
> +/*
> + * SPDX-License-Identifier: GPL-2.0-or-later
> + * Copyright (C) 2023 IBM Corp.
> + *
> + * IBM Local bus and connected device structures.
> + */
> +#ifndef FSI_LBUS_H
> +#define FSI_LBUS_H
> +
> +#include "exec/memory.h"
> +#include "hw/qdev-core.h"
> +
> +#define TYPE_LBUS_DEVICE "lbus.device"
> +OBJECT_DECLARE_TYPE(LBusDevice, LBusDeviceClass, LBUS_DEVICE)

Using an "fsi/FSI"  prefix for all definitions seems like a good idea
to avoid namespace conflicts.

> +typedef struct LBusDevice {
> +    DeviceState parent;
> +
> +    MemoryRegion iomem;
> +    uint32_t address;
> +} LBusDevice;
> +
> +typedef struct LBusDeviceClass {
> +    DeviceClass parent;
> +
> +    uint32_t config;
> +} LBusDeviceClass;
> +
> +typedef struct LBusNode {
> +    LBusDevice *ldev;
> +
> +    QLIST_ENTRY(LBusNode) next;
> +} LBusNode;
> +
> +#define TYPE_LBUS "lbus"
> +OBJECT_DECLARE_SIMPLE_TYPE(LBus, LBUS)
> +
> +typedef struct LBus {
> +    BusState bus;
> +
> +    MemoryRegion mr;
> +
> +    QLIST_HEAD(, LBusNode) devices;

BusState already has a list. I think this needs to be reworked.

 
> +} LBus;
> +
> +DeviceState *lbus_create_device(LBus *bus, const char *type, uint32_t addr);
> +int lbus_add_device(LBus *bus, LBusDevice *dev);
> +#endif /* FSI_LBUS_H */
> diff --git a/include/qemu/bitops.h b/include/qemu/bitops.h
> index cb3526d1f4..e12496f619 100644
> --- a/include/qemu/bitops.h
> +++ b/include/qemu/bitops.h
> @@ -618,4 +618,10 @@ static inline uint64_t half_unshuffle64(uint64_t x)
>       return x;
>   }
>   
> +/* Bitwise operations at the word level. */
> +#define BE_BIT(x)                          BIT(31 - (x))
> +#define GENMASK(t, b) \
> +    (((1ULL << ((t) + 1)) - 1) & ~((1ULL << (b)) - 1))
> +#define BE_GENMASK(t, b)                   GENMASK(BE_BIT(t), BE_BIT(b))

I think we should rework the code to make these macro local to the fsi
subsystem, in the fsi.h file, or even better get rid of them.

Thanks,

C.

 
>   #endif