[PATCH] drm/amdgpu: Add support for page queue scheduling

[Alex Deucher]

On Tue, Feb 11, 2025 at 4:02 AM Jesse.zhang at amd.com <jesse.zhang at amd.com> wrote:
>
> This patch updates the sdma engine to support scheduling for
> the page queue. The main changes include:
>
> - Introduce a new variable `page` to handle the page queue if it exists.
> - Update the scheduling logic to conditionally set the `sched.ready` flag for
>   both the sdma gfx queue and the page queue based on the provided mask.
> - Ensure that the scheduling flags are updated correctly for both queues when
>   the mask is applied.
>
> The patch ensures that the SDMA engine can handle scheduling for both the sdma gfx
> queue and the page queue,
>
> Signed-off-by: Jesse Zhang <jesse.zhang at amd.com>
> ---
>  drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.c | 14 +++++++++++---
>  1 file changed, 11 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.c
> index 6ba785798a4a..e82ded95540c 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.c
> @@ -358,7 +358,7 @@ static int amdgpu_debugfs_sdma_sched_mask_set(void *data, u64 val)
>         struct amdgpu_device *adev = (struct amdgpu_device *)data;
>         u32 i;
>         u64 mask = 0;
> -       struct amdgpu_ring *ring;
> +       struct amdgpu_ring *ring, *page;
>
>         if (!adev)
>                 return -ENODEV;
> @@ -369,10 +369,18 @@ static int amdgpu_debugfs_sdma_sched_mask_set(void *data, u64 val)
>
>         for (i = 0; i < adev->sdma.num_instances; ++i) {
>                 ring = &adev->sdma.instance[i].ring;
> -               if (val & BIT_ULL(i))
> +               if (adev->sdma.has_page_queue)
> +                       page = &adev->sdma.instance[i].page;
> +               if (val & BIT_ULL(i)) {
>                         ring->sched.ready = true;
> -               else
> +                       if (adev->sdma.has_page_queue)
> +                               page->sched.ready = true;
> +               } else {
>                         ring->sched.ready = false;
> +                       if (adev->sdma.has_page_queue)
> +                               page->sched.ready = false;
> +               }
> +

Not really specific to this patch, but if we disable schedulers here,
we may disable the buffer_funcs scheduler used by the driver for
memory management.

Alex

>         }
>         /* publish sched.ready flag update effective immediately across smp */
>         smp_rmb();
> --
> 2.25.1
>