[v7 04/11] drm/amdgpu: Add helper functions for user queue preemption and restoration

[Alex Deucher]

On Tue, Aug 5, 2025 at 10:39 PM Jesse.Zhang <Jesse.Zhang at amd.com> wrote:
>
> This patch introduces two new helper functions to manage user queue
> preemption and restoration:
>
> 1. amdgpu_userqueue_preempt_helper() - Handles preempting a user queue
>    by calling the appropriate IP-specific preempt function and updating
>    the queue state. If preemption fails, it marks the queue as hung and
>    triggers queue detection/reset.
>
> 2. amdgpu_userqueue_restore_helper() - Handles restoring a preempted
>    user queue by calling the IP-specific restore function. On failure,
>    it marks the queue as hung and triggers a GPU reset.
>
> The helpers properly manage queue state transitions between MAPPED,
> PREEMPTED, and HUNG states, and handle error cases by initiating
> appropriate recovery actions.
>
> These functions will be used by subsequent patches to implement
> user queue preemption support in the driver.
>
> Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
> Signed-off-by: Jesse Zhang <Jesse.Zhang at amd.com>
> ---
>  drivers/gpu/drm/amd/amdgpu/amdgpu_userq.c | 48 +++++++++++++++++++++++
>  1 file changed, 48 insertions(+)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_userq.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_userq.c
> index aac0de86f3e8..1496544cd1c2 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_userq.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_userq.c
> @@ -44,6 +44,54 @@ u32 amdgpu_userq_get_supported_ip_mask(struct amdgpu_device *adev)
>         return userq_ip_mask;
>  }
>
> +static int
> +amdgpu_userqueue_preempt_helper(struct amdgpu_userq_mgr *uq_mgr,
> +                         struct amdgpu_usermode_queue *queue)
> +{
> +       struct amdgpu_device *adev = uq_mgr->adev;
> +       const struct amdgpu_userq_funcs *userq_funcs =
> +               adev->userq_funcs[queue->queue_type];
> +       int r = 0;
> +
> +       if (queue->state == AMDGPU_USERQ_STATE_MAPPED) {
> +               r = userq_funcs->preempt(uq_mgr, queue);
> +               if (r) {
> +                       amdgpu_userq_detect_and_reset_queues(uq_mgr);

This function isn't available yet.  This should be part of a later patch.

> +                       queue->state = AMDGPU_USERQ_STATE_HUNG;
> +               } else {
> +                       queue->state = AMDGPU_USERQ_STATE_PREEMPTED;
> +               }
> +       }
> +
> +       return r;
> +}
> +
> +static int
> +amdgpu_userqueue_restore_helper(struct amdgpu_userq_mgr *uq_mgr,
> +                       struct amdgpu_usermode_queue *queue)
> +{
> +       struct amdgpu_device *adev = uq_mgr->adev;
> +       const struct amdgpu_userq_funcs *userq_funcs =
> +               adev->userq_funcs[queue->queue_type];
> +       bool gpu_reset = false;
> +       int r = 0;
> +
> +       if (queue->state == AMDGPU_USERQ_STATE_PREEMPTED) {
> +               r = userq_funcs->restore(uq_mgr, queue);
> +               if (r) {
> +                       queue->state = AMDGPU_USERQ_STATE_HUNG;
> +                       gpu_reset = true;
> +               } else {
> +                       queue->state = AMDGPU_USERQ_STATE_MAPPED;
> +               }
> +       }
> +
> +       if (gpu_reset)
> +               amdgpu_userq_gpu_reset(adev);

Same here.

Alex

> +
> +       return r;
> +}
> +
>  static int
>  amdgpu_userq_unmap_helper(struct amdgpu_userq_mgr *uq_mgr,
>                           struct amdgpu_usermode_queue *queue)
> --
> 2.49.0
>