Re: [Qemu-devel] [PATCH v2 4/5] acpi: arm: add fw_cfg device node to dsdt

[Shannon Zhao]

On 2015/9/14 22:57, Gabriel L. Somlo wrote:
> Add a fw_cfg device node to the ACPI DSDT. This is mostly
> informational, as the authoritative fw_cfg MMIO region(s)
> are listed in the Device Tree. However, since we are building
> ACPI tables, we might as well be thorough while at it...
> 
> Signed-off-by: Gabriel Somlo <address@hidden>
> ---
>  hw/arm/virt-acpi-build.c | 13 +++++++++++++
>  1 file changed, 13 insertions(+)
> 
> diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c
> index 9088248..dcf9752 100644
> --- a/hw/arm/virt-acpi-build.c
> +++ b/hw/arm/virt-acpi-build.c
> @@ -110,6 +110,18 @@ static void acpi_dsdt_add_rtc(Aml *scope, const 
> MemMapEntry *rtc_memmap,
>      aml_append(scope, dev);
>  }
>  
> +static void acpi_dsdt_add_fw_cfg(Aml *scope, const MemMapEntry 
> *fw_cfg_memmap)
> +{
> +    Aml *dev = aml_device("FWCF");
> +    aml_append(dev, aml_name_decl("_HID", aml_string("QEMU0002")));
> +
> +    Aml *crs = aml_resource_template();
> +    aml_append(crs, aml_memory32_fixed(fw_cfg_memmap->base,
> +                                       fw_cfg_memmap->size, AML_READ_WRITE));
> +    aml_append(dev, aml_name_decl("_CRS", crs));
> +    aml_append(scope, dev);
> +}
> +
>  static void acpi_dsdt_add_flash(Aml *scope, const MemMapEntry *flash_memmap)
>  {
>      Aml *dev, *crs;
> @@ -519,6 +531,7 @@ build_dsdt(GArray *table_data, GArray *linker, 
> VirtGuestInfo *guest_info)
>                         (irqmap[VIRT_UART] + ARM_SPI_BASE));
>      acpi_dsdt_add_rtc(scope, &memmap[VIRT_RTC],
>                        (irqmap[VIRT_RTC] + ARM_SPI_BASE));
> +    acpi_dsdt_add_fw_cfg(scope, &memmap[VIRT_FW_CFG]);
>      acpi_dsdt_add_flash(scope, &memmap[VIRT_FLASH]);
>      acpi_dsdt_add_virtio(scope, &memmap[VIRT_MMIO],
>                      (irqmap[VIRT_MMIO] + ARM_SPI_BASE), 
> NUM_VIRTIO_TRANSPORTS);
> 

This looks fine to me. But from what you said, the kernel driver is not
in upstream kernel yet, so this would be applied after the kernel patch
applied in case of unexpected change.

Thanks,
-- 
Shannon