[PATCH 2/2] drm/amdgpu/userq: take the userq_mgr lock in enforce isolation

[Yadav, Arvind]

Reviewed-by: Arvind Yadav <Arvind.Yadav at amd.com>

On 4/26/2025 12:04 AM, Alex Deucher wrote:
> Add the missing locking.
>
> Fixes: 94976e7e5ede ("drm/amdgpu/userq: add helpers to start/stop scheduling")
> Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_userq.c | 4 ++++
>   1 file changed, 4 insertions(+)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_userq.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_userq.c
> index 1fa9d2be87f39..afbe01149ed3f 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_userq.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_userq.c
> @@ -865,6 +865,7 @@ int amdgpu_userq_stop_sched_for_enforce_isolation(struct amdgpu_device *adev,
>   	adev->userq_halt_for_enforce_isolation = true;
>   	list_for_each_entry_safe(uqm, tmp, &adev->userq_mgr_list, list) {
>   		cancel_delayed_work_sync(&uqm->resume_work);
> +		mutex_lock(&uqm->userq_mutex);
>   		idr_for_each_entry(&uqm->userq_idr, queue, queue_id) {
>   			if (((queue->queue_type == AMDGPU_HW_IP_GFX) ||
>   			     (queue->queue_type == AMDGPU_HW_IP_COMPUTE)) &&
> @@ -874,6 +875,7 @@ int amdgpu_userq_stop_sched_for_enforce_isolation(struct amdgpu_device *adev,
>   					ret = r;
>   			}
>   		}
> +		mutex_unlock(&uqm->userq_mutex);
>   	}
>   	mutex_unlock(&adev->userq_mutex);
>   	return ret;
> @@ -897,6 +899,7 @@ int amdgpu_userq_start_sched_for_enforce_isolation(struct amdgpu_device *adev,
>   		dev_warn(adev->dev, "userq scheduling already started!\n");
>   	adev->userq_halt_for_enforce_isolation = false;
>   	list_for_each_entry_safe(uqm, tmp, &adev->userq_mgr_list, list) {
> +		mutex_lock(&uqm->userq_mutex);
>   		idr_for_each_entry(&uqm->userq_idr, queue, queue_id) {
>   			if (((queue->queue_type == AMDGPU_HW_IP_GFX) ||
>   			     (queue->queue_type == AMDGPU_HW_IP_COMPUTE)) &&
> @@ -906,6 +909,7 @@ int amdgpu_userq_start_sched_for_enforce_isolation(struct amdgpu_device *adev,
>   					ret = r;
>   			}
>   		}
> +		mutex_unlock(&uqm->userq_mutex);
>   	}
>   	mutex_unlock(&adev->userq_mutex);
>   	return ret;