Re: [Qemu-trivial] [Qemu-devel] [PATCH 03/10] sm501: QOMify

[Peter Maydell]

On 24 February 2017 at 20:23, BALATON Zoltan <address@hidden> wrote:
> On Fri, 24 Feb 2017, Peter Maydell wrote:
>>
>> On 19 February 2017 at 16:35, BALATON Zoltan <address@hidden> wrote:
>>>
>>> Signed-off-by: BALATON Zoltan <address@hidden>
>>> ---
>>>  hw/display/sm501.c   | 133
>>> +++++++++++++++++++++++++++++++++++----------------
>>>  hw/sh4/r2d.c         |  11 ++++-
>>>  include/hw/devices.h |   5 --
>>>  3 files changed, 101 insertions(+), 48 deletions(-)
>>>
>>> diff --git a/hw/display/sm501.c b/hw/display/sm501.c
>>> index 4eb085c..b592022 100644
>>> --- a/hw/display/sm501.c
>>> +++ b/hw/display/sm501.c
>>> @@ -58,8 +58,8 @@
>>>  #define SM501_DPRINTF(fmt, ...) do {} while (0)
>>>  #endif
>>>
>>> -
>>>  #define MMIO_BASE_OFFSET 0x3e00000
>>> +#define MMIO_SIZE 0x200000
>>>
>>>  /* SM501 register definitions taken from
>>> "linux/include/linux/sm501-regs.h" */
>>>
>>> @@ -464,6 +464,7 @@ typedef struct SM501State {
>>>      uint32_t local_mem_size_index;
>>>      uint8_t *local_mem;
>>>      MemoryRegion local_mem_region;
>>> +    MemoryRegion mmio_region;
>>>      uint32_t last_width;
>>>      uint32_t last_height;
>>>
>>> @@ -1396,20 +1397,14 @@ static const GraphicHwOps sm501_ops = {
>>>      .gfx_update  = sm501_update_display,
>>>  };
>>>
>>> -void sm501_init(MemoryRegion *address_space_mem, uint32_t base,
>>> -                uint32_t local_mem_bytes, qemu_irq irq, Chardev *chr)
>>> +static void sm501_init(SM501State *s, DeviceState *dev, uint32_t base,
>>> +                       uint32_t local_mem_bytes)
>>>  {
>>> -    SM501State *s;
>>> -    DeviceState *dev;
>>> -    MemoryRegion *sm501_system_config = g_new(MemoryRegion, 1);
>>> -    MemoryRegion *sm501_disp_ctrl = g_new(MemoryRegion, 1);
>>> -    MemoryRegion *sm501_2d_engine = g_new(MemoryRegion, 1);
>>> -
>>> -    /* allocate management data region */
>>> -    s = g_new0(SM501State, 1);
>>> +    MemoryRegion *mr;
>>> +
>>>      s->base = base;
>>>      s->local_mem_size_index = get_local_mem_size_index(local_mem_bytes);
>>> -    SM501_DPRINTF("local mem size=%x. index=%d\n",
>>> get_local_mem_size(s),
>>> +    SM501_DPRINTF("sm501 local mem size=%x. index=%d\n",
>>> get_local_mem_size(s),
>>>                    s->local_mem_size_index);
>>>      s->system_control = 0x00100000; /* 2D engine FIFO empty */
>>>      s->misc_control = SM501_MISC_IRQ_INVERT; /* assumes SH, active=low
>>> */
>>> @@ -1417,46 +1412,102 @@ void sm501_init(MemoryRegion *address_space_mem,
>>> uint32_t base,
>>>      s->dc_crt_control = 0x00010000;
>>>
>>>      /* allocate local memory */
>>> -    memory_region_init_ram(&s->local_mem_region, NULL, "sm501.local",
>>> +    memory_region_init_ram(&s->local_mem_region, OBJECT(dev),
>>> "sm501.local",
>>>                             local_mem_bytes, &error_fatal);
>>>      vmstate_register_ram_global(&s->local_mem_region);
>>>      memory_region_set_log(&s->local_mem_region, true, DIRTY_MEMORY_VGA);
>>>      s->local_mem = memory_region_get_ram_ptr(&s->local_mem_region);
>>> -    memory_region_add_subregion(address_space_mem, base,
>>> &s->local_mem_region);
>>> -
>>> -    /* map mmio */
>>> -    memory_region_init_io(sm501_system_config, NULL,
>>> &sm501_system_config_ops,
>>> -                          s, "sm501-system-config", 0x6c);
>>> -    memory_region_add_subregion(address_space_mem, base +
>>> MMIO_BASE_OFFSET,
>>> -                                sm501_system_config);
>>> -    memory_region_init_io(sm501_disp_ctrl, NULL, &sm501_disp_ctrl_ops,
>>> s,
>>> +
>>> +    /* allocate mmio */
>>> +    memory_region_init(&s->mmio_region, OBJECT(dev), "sm501.mmio",
>>> MMIO_SIZE);
>>> +    mr = g_new(MemoryRegion, 1);
>>
>>
>> There's no need to dynamically allocate any of these memory regions;
>> just make them be MemoryRegion fields inside SM501State.
>>
>>> +    memory_region_init_io(mr, OBJECT(dev), &sm501_system_config_ops, s,
>>> +                          "sm501-system-config", 0x6c);
>>> +    memory_region_add_subregion(&s->mmio_region, SM501_SYS_CONFIG, mr);
>>> +    mr = g_new(MemoryRegion, 1);
>>> +    memory_region_init_io(mr, OBJECT(dev), &sm501_disp_ctrl_ops, s,
>>>                            "sm501-disp-ctrl", 0x1000);
>>> -    memory_region_add_subregion(address_space_mem,
>>> -                                base + MMIO_BASE_OFFSET + SM501_DC,
>>> -                                sm501_disp_ctrl);
>>> -    memory_region_init_io(sm501_2d_engine, NULL, &sm501_2d_engine_ops,
>>> s,
>>> +    memory_region_add_subregion(&s->mmio_region, SM501_DC, mr);
>>> +    mr = g_new(MemoryRegion, 1);
>>> +    memory_region_init_io(mr, OBJECT(dev), &sm501_2d_engine_ops, s,
>>>                            "sm501-2d-engine", 0x54);
>>> -    memory_region_add_subregion(address_space_mem,
>>> -                                base + MMIO_BASE_OFFSET +
>>> SM501_2D_ENGINE,
>>> -                                sm501_2d_engine);
>>> +    memory_region_add_subregion(&s->mmio_region, SM501_2D_ENGINE, mr);
>>> +
>>> +    /* create qemu graphic console */
>>> +    s->con = graphic_console_init(DEVICE(dev), 0, &sm501_ops, s);
>>> +}
>>> +
>>> +#define TYPE_SYSBUS_SM501 "sysbus-sm501"
>>> +#define SYSBUS_SM501(obj) \
>>> +    OBJECT_CHECK(SM501SysBusState, (obj), TYPE_SYSBUS_SM501)
>>> +
>>> +typedef struct {
>>> +    /*< private >*/
>>> +    SysBusDevice parent_obj;
>>> +    /*< public >*/
>>> +    SM501State state;
>>> +    uint32_t vram_size;
>>> +    uint32_t base;
>>> +    void *chr_state;
>>> +} SM501SysBusState;
>>> +
>>> +static void sm501_realize_sysbus(DeviceState *dev, Error **errp)
>>> +{
>>> +    SM501SysBusState *s = SYSBUS_SM501(dev);
>>> +    SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
>>> +    DeviceState *usb_dev;
>>> +
>>> +    sm501_init(&s->state, dev, s->base, s->vram_size);
>>> +    sysbus_init_mmio(sbd, &s->state.local_mem_region);
>>> +    sysbus_init_mmio(sbd, &s->state.mmio_region);
>>>
>>>      /* bridge to usb host emulation module */
>>> -    dev = qdev_create(NULL, "sysbus-ohci");
>>> -    qdev_prop_set_uint32(dev, "num-ports", 2);
>>> -    qdev_prop_set_uint64(dev, "dma-offset", base);
>>> -    qdev_init_nofail(dev);
>>> -    sysbus_mmio_map(SYS_BUS_DEVICE(dev), 0,
>>> -                    base + MMIO_BASE_OFFSET + SM501_USB_HOST);
>>> -    sysbus_connect_irq(SYS_BUS_DEVICE(dev), 0, irq);
>>> +    usb_dev = qdev_create(NULL, "sysbus-ohci");
>>> +    qdev_prop_set_uint32(usb_dev, "num-ports", 2);
>>> +    qdev_prop_set_uint64(usb_dev, "dma-offset", s->base);
>>> +    qdev_init_nofail(usb_dev);
>>
>>
>> Why is a display controller device creating a USB controller?
>> This looks like something that should be being done by the board.
>>
>>> +    memory_region_add_subregion(&s->state.mmio_region, SM501_USB_HOST,
>>> +                       sysbus_mmio_get_region(SYS_BUS_DEVICE(usb_dev),
>>> 0));
>>> +    sysbus_pass_irq(sbd, SYS_BUS_DEVICE(usb_dev));
>>>
>>>      /* bridge to serial emulation module */
>>> -    if (chr) {
>>> -        serial_mm_init(address_space_mem,
>>> -                       base + MMIO_BASE_OFFSET + SM501_UART0, 2,
>>> +    if (s->chr_state) {
>>> +        serial_mm_init(&s->state.mmio_region, SM501_UART0, 2,
>>>                         NULL, /* TODO : chain irq to IRL */
>>> -                       115200, chr, DEVICE_NATIVE_ENDIAN);
>>> +                       115200, s->chr_state, DEVICE_NATIVE_ENDIAN);
>>>      }
>>> +}
>>
>>
>> Similarly, what's going on here with the serial?
>
>
> The SM501/SM502 is a multimedia chip that besides a display controller also
> contains some other functions (see
> http://cateee.net/lkddb/web-lkddb/MFD_SM501.html) and this is what is
> emulated here as these are part of the chip itself.

Hmm; that's pretty ugly but I guess it's sort of like a container
device that needs to contain various things inside it.

>>>
>>> -    /* create qemu graphic console */
>>> -    s->con = graphic_console_init(DEVICE(dev), 0, &sm501_ops, s);
>>> +static Property sm501_sysbus_properties[] = {
>>> +    DEFINE_PROP_UINT32("vram-size", SM501SysBusState, vram_size, 0),
>>> +    DEFINE_PROP_UINT32("base", SM501SysBusState, base, 0),
>>> +    DEFINE_PROP_PTR("chr-state", SM501SysBusState, chr_state),

Pointer properties and properties which tell the device what
address it's at are both signs that something's not quite
modelled right. There may be no better way to do things right
now, or then again there may be.

>>> +    DEFINE_PROP_END_OF_LIST(),
>>> +};
>>
>>
>>> +static void sm501_sysbus_class_init(ObjectClass *klass, void *data)
>>> +{
>>> +    DeviceClass *dc = DEVICE_CLASS(klass);
>>> +
>>> +    dc->realize = sm501_realize_sysbus;
>>> +    set_bit(DEVICE_CATEGORY_DISPLAY, dc->categories);
>>> +    dc->desc = "SM501 Multimedia Companion";
>>> +    dc->props = sm501_sysbus_properties;
>>> +/* Note: pointer property "chr-state" may remain null, thus
>>> + * no need for dc->cannot_instantiate_with_device_add_yet = true;
>>> + */
>>> }
>>
>>
>> You also need a VMState struct registered in dc->vmsd and a reset
>> function registered in dc->reset.
>
>
> Even if no migration is supported? Is there a simple example I could look at
> on what should go into these?

The idea is to support migration. There are examples of doing
VMState structures all over the tree. You just need a structure
that lists all the bits of your state data structure that
contain guest-modifiable state.

Reset is straightforward: it's just a function that resets
the state of the device as if the system had been hard
powercycled.

thanks
-- PMM