Re: [PATCH 3/6] hw/sd/allwinner-sdhost: Do DMA accesses via DMA address space

[Philippe Mathieu-Daudé]

On 5/31/20 7:54 PM, Philippe Mathieu-Daudé wrote:
> The DMA operations should not use the CPU address space, but
> the DMA address space. Add support for a DMA address space,
> and replace the cpu_physical_memory API calls by equivalent
> dma_memory_read/write calls.
> 
> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
> ---
>  include/hw/sd/allwinner-sdhost.h |  4 ++++
>  hw/sd/allwinner-sdhost.c         | 36 ++++++++++++++++++++++++++------
>  2 files changed, 34 insertions(+), 6 deletions(-)
> 
[...]> @@ -742,6 +747,17 @@ static void allwinner_sdhost_init(Object *obj)
>      sysbus_init_irq(SYS_BUS_DEVICE(s), &s->irq);
>  }
>  
> +static void allwinner_sdhost_realize(DeviceState *dev, Error **errp)
> +{
> +    AwSdHostState *s = AW_SDHOST(dev);
> +
> +    if (!s->dma_mr) {
> +        error_setg(errp, "\"dma\" property must be provided.");

Oops I forgot to include the part that sets this property in the A10/H3
SoCs.

> +        return;
> +    }
> +    address_space_init(&s->dma_as, s->dma_mr, "sdhost-dma");
> +}
> +
>  static void allwinner_sdhost_reset(DeviceState *dev)
>  {
>      AwSdHostState *s = AW_SDHOST(dev);
> @@ -787,6 +803,12 @@ static void allwinner_sdhost_reset(DeviceState *dev)
>      s->status_crc = REG_SD_CRC_STA_RST;
>  }
>  
> +static Property allwinner_sdhost_properties[] = {
> +    DEFINE_PROP_LINK("dma", AwSdHostState,
> +                     dma_mr, TYPE_MEMORY_REGION, MemoryRegion *),
> +    DEFINE_PROP_END_OF_LIST(),
> +};
> +
>  static void allwinner_sdhost_bus_class_init(ObjectClass *klass, void *data)
>  {
>      SDBusClass *sbc = SD_BUS_CLASS(klass);
> @@ -798,7 +820,9 @@ static void allwinner_sdhost_class_init(ObjectClass 
> *klass, void *data)
>  {
>      DeviceClass *dc = DEVICE_CLASS(klass);
>  
> +    device_class_set_props(dc, allwinner_sdhost_properties);
>      dc->reset = allwinner_sdhost_reset;
> +    dc->realize = allwinner_sdhost_realize;
>      dc->vmsd = &vmstate_allwinner_sdhost;
>  }
>  
>