On Mon, Mar 20, 2023 at 8:31 PM Marek Olšák <maraeo@gmail.com> wrote:
>
> On Mon, Mar 20, 2023 at 1:38 PM Alex Deucher <alexander.deucher@amd.com> wrote:
>>
>> Add UAPI to query the GFX shadow buffer requirements
>> for preemption on GFX11. UMDs need to specify the shadow
>> areas for preemption.
>>
>> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
>> ---
>> include/uapi/drm/amdgpu_drm.h | 10 ++++++++++
>> 1 file changed, 10 insertions(+)
>>
>> diff --git a/include/uapi/drm/amdgpu_drm.h b/include/uapi/drm/amdgpu_drm.h
>> index 3d9474af6566..19a806145371 100644
>> --- a/include/uapi/drm/amdgpu_drm.h
>> +++ b/include/uapi/drm/amdgpu_drm.h
>> @@ -886,6 +886,7 @@ struct drm_amdgpu_cs_chunk_cp_gfx_shadow {
>> #define AMDGPU_INFO_VIDEO_CAPS_DECODE 0
>> /* Subquery id: Encode */
>> #define AMDGPU_INFO_VIDEO_CAPS_ENCODE 1
>> +#define AMDGPU_INFO_CP_GFX_SHADOW_SIZE 0x22
>
>
> Can you put this into the device structure instead? Let's minimize the number of kernel queries as much as possible.
I guess, but one nice thing about this is that we can use the query as
a way to determine if the kernel supports this functionality or not.
If not, the query returns -ENOTSUP.
That should be another flag in the device info structure or the sizes should be 0. There is never a reason to add a new single-value INFO query.