Re: [PATCH v5 01/10] hw/fsi: Introduce IBM's Local bus

[Ninad Palsule <ninad@linux.ibm.com>]

Hello Cedric,

On 10/19/23 03:03, Cédric Le Goater wrote:
> On 10/11/23 17:13, 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.
>> v5:
>> - Incorporated review comments by Cedric.
>> ---
>>   include/hw/fsi/lbus.h | 51 +++++++++++++++++++++++++
>>   include/qemu/bitops.h |  6 +++
>>   hw/fsi/lbus.c         | 87 +++++++++++++++++++++++++++++++++++++++++++
>>   hw/Kconfig            |  1 +
>>   hw/fsi/Kconfig        |  2 +
>>   hw/fsi/meson.build    |  1 +
>>   hw/meson.build        |  1 +
>>   7 files changed, 149 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
>>
>> diff --git a/include/hw/fsi/lbus.h b/include/hw/fsi/lbus.h
>> new file mode 100644
>> index 0000000000..408fe25831
>> --- /dev/null
>> +++ b/include/hw/fsi/lbus.h
>> @@ -0,0 +1,51 @@
>> +/*
>> + * 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_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;
>> +} FSILBusDevice;
>> +
>> +typedef struct FSILBusDeviceClass {
>> +    DeviceClass parent;
>> +
>> +    uint32_t config;
>> +} FSILBusDeviceClass;
>> +
>> +typedef struct FSILBusNode {
>> +    FSILBusDevice *ldev;
>> +
>> +    QLIST_ENTRY(FSILBusNode) next;
>> +} FSILBusNode;
>> +
>> +#define TYPE_FSI_LBUS "fsi.lbus"
>> +OBJECT_DECLARE_SIMPLE_TYPE(FSILBus, FSI_LBUS)
>> +
>> +typedef struct FSILBus {
>> +    BusState bus;
>> +
>> +    MemoryRegion mr;
>> +
>> +    QLIST_HEAD(, FSILBusNode) devices;
>> +} FSILBus;
>> +
>> +DeviceState *lbus_create_device(FSILBus *bus, const char *type, 
>> uint32_t addr);
>> +int lbus_add_device(FSILBus *bus, FSILBusDevice *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))
>> +
>>   #endif
>> diff --git a/hw/fsi/lbus.c b/hw/fsi/lbus.c
>> new file mode 100644
>> index 0000000000..d7117d1299
>> --- /dev/null
>> +++ b/hw/fsi/lbus.c
>> @@ -0,0 +1,87 @@
>> +/*
>> + * 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_realize(BusState *bus, Error **errp)
>> +{
>> +    FSILBusNode *node;
>> +    FSILBus *lbus = FSI_LBUS(bus);
>> +
>> +    memory_region_init(&lbus->mr, OBJECT(lbus), TYPE_FSI_LBUS,
>> +                       FSI_LBUS_MEM_REGION_SIZE - 
>> FSI_LBUSDEV_IOMEM_SIZE);
>
> the region init should be done in an init handler (this to avoid the 
> realize
> of the bus)
Fixed.
>
>> +
>> +    QLIST_FOREACH(node, &lbus->devices, next) {
>> +        memory_region_add_subregion(&lbus->mr, node->ldev->address,
>> + &node->ldev->iomem);
>
> This is redudant with what is done in cfam_realize() and please
> remove this list, also redudant with the bus list.

Removed the list and used the children. Removed the lbus_realize() function.

Thanks for the review.

~Ninad

>
> Thanks,
>
> C.
>
>> +    }
>> +}
>> +
>> +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_FSI_LBUS,
>> +    .parent = TYPE_BUS,
>> +    .instance_size = sizeof(FSILBus),
>> +    .class_init = lbus_class_init,
>> +};
>> +
>> +static Property lbus_device_props[] = {
>> +    DEFINE_PROP_UINT32("address", FSILBusDevice, address, 0),
>> +    DEFINE_PROP_END_OF_LIST(),
>> +};
>> +
>> +DeviceState *lbus_create_device(FSILBus *bus, const char *type, 
>> uint32_t addr)
>> +{
>> +    DeviceState *dev;
>> +    FSILBusNode *node;
>> +    BusState *state = BUS(bus);
>> +
>> +    dev = qdev_new(type);
>> +    qdev_prop_set_uint8(dev, "address", addr);
>> +    qdev_realize_and_unref(dev, state, &error_fatal);
>> +
>> +    /* Move to post_load */
>> +    node = g_malloc(sizeof(struct FSILBusNode));
>> +    node->ldev = FSI_LBUS_DEVICE(dev);
>> +    QLIST_INSERT_HEAD(&bus->devices, node, next);
>> +
>> +    return dev;
>> +}
>> +
>> +static void lbus_device_class_init(ObjectClass *klass, void *data)
>> +{
>> +    DeviceClass *dc = DEVICE_CLASS(klass);
>> +
>> +    dc->bus_type = TYPE_FSI_LBUS;
>> +    device_class_set_props(dc, lbus_device_props);
>> +}
>> +
>> +static const TypeInfo lbus_device_type_info = {
>> +    .name = TYPE_FSI_LBUS_DEVICE,
>> +    .parent = TYPE_DEVICE,
>> +    .instance_size = sizeof(FSILBusDevice),
>> +    .abstract = true,
>> +    .class_init = lbus_device_class_init,
>> +    .class_size = sizeof(FSILBusDeviceClass),
>> +};
>> +
>> +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/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..e650c660f0
>> --- /dev/null
>> +++ b/hw/fsi/Kconfig
>> @@ -0,0 +1,2 @@
>> +config FSI_LBUS
>> +    bool
>> diff --git a/hw/fsi/meson.build b/hw/fsi/meson.build
>> new file mode 100644
>> index 0000000000..4074d3a7d2
>> --- /dev/null
>> +++ b/hw/fsi/meson.build
>> @@ -0,0 +1 @@
>> +system_ss.add(when: 'CONFIG_FSI_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')
>