[PATCH 8/9] drm/amdgpu/userq: add helpers to start/stop scheduling

[Khatri, Sunil]

On 4/11/2025 7:42 PM, Alex Deucher wrote:
> This will be used to stop/start user queue scheduling for
> example when switching between kernel and user queues when
> enforce isolation is enabled.
>
> Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu.h           |  1 +
>   drivers/gpu/drm/amd/amdgpu/amdgpu_userqueue.c | 68 ++++++++++++++++---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_userqueue.h |  3 +
>   3 files changed, 64 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> index b156e31ac86ac..30c485f529d17 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> @@ -1249,6 +1249,7 @@ struct amdgpu_device {
>   
>   	struct list_head		userq_mgr_list;
>   	struct mutex                    userq_mutex;
> +	bool                            userq_halt;
>   };
>   
>   static inline uint32_t amdgpu_ip_version(const struct amdgpu_device *adev,
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_userqueue.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_userqueue.c
> index aa7222137c31d..e93e390f4e301 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_userqueue.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_userqueue.c
> @@ -335,6 +335,7 @@ amdgpu_userqueue_create(struct drm_file *filp, union drm_amdgpu_userq *args)
>   		goto unlock;
>   	}
>   
> +
>   	qid = idr_alloc(&uq_mgr->userq_idr, queue, 1, AMDGPU_MAX_USERQ_COUNT, GFP_KERNEL);
>   	if (qid < 0) {
>   		DRM_ERROR("Failed to allocate a queue id\n");
> @@ -345,15 +346,21 @@ amdgpu_userqueue_create(struct drm_file *filp, union drm_amdgpu_userq *args)
>   		goto unlock;
>   	}
>   
> -	r = uq_funcs->map(uq_mgr, queue);
> -	if (r) {
> -		DRM_ERROR("Failed to map Queue\n");
> -		idr_remove(&uq_mgr->userq_idr, qid);
> -		amdgpu_userq_fence_driver_free(queue);
> -		uq_funcs->mqd_destroy(uq_mgr, queue);
> -		kfree(queue);
> -		goto unlock;
> +	/* don't map the queue if scheduling is halted */
> +	mutex_lock(&adev->userq_mutex);
> +	if (!adev->userq_halt) {
> +		r = uq_funcs->map(uq_mgr, queue);
> +		if (r) {
> +			DRM_ERROR("Failed to map Queue\n");
> +			mutex_unlock(&adev->userq_mutex);
> +			idr_remove(&uq_mgr->userq_idr, qid);
> +			amdgpu_userq_fence_driver_free(queue);
> +			uq_funcs->mqd_destroy(uq_mgr, queue);
> +			kfree(queue);
> +			goto unlock;
> +		}
>   	}
> +	mutex_unlock(&adev->userq_mutex);
>   
>   	args->out.queue_id = qid;
>   
> @@ -720,3 +727,48 @@ int amdgpu_userq_resume(struct amdgpu_device *adev)
>   	mutex_unlock(&adev->userq_mutex);
>   	return ret;
>   }
> +
> +int amdgpu_userq_stop_sched(struct amdgpu_device *adev, u32 idx)
Did i miss something of the param "idx" isnt being used in this function 
? Same is applicable for start shed .
Regards
Sunil
> +{
> +	const struct amdgpu_userq_funcs *userq_funcs;
> +	struct amdgpu_usermode_queue *queue;
> +	struct amdgpu_userq_mgr *uqm, *tmp;
> +	int queue_id;
> +	int ret = 0;
> +
> +	mutex_lock(&adev->userq_mutex);
> +	if (adev->userq_halt)
> +		dev_warn(adev->dev, "userq scheduling already stopped!\n");
> +	adev->userq_halt = true;
> +	list_for_each_entry_safe(uqm, tmp, &adev->userq_mgr_list, list) {
> +		cancel_delayed_work_sync(&uqm->resume_work);
> +		idr_for_each_entry(&uqm->userq_idr, queue, queue_id) {
> +			userq_funcs = adev->userq_funcs[queue->queue_type];
> +			ret |= userq_funcs->unmap(uqm, queue);
> +		}
> +	}
> +	mutex_unlock(&adev->userq_mutex);
> +	return ret;
> +}
> +
> +int amdgpu_userq_start_sched(struct amdgpu_device *adev, u32 idx)
> +{
> +	const struct amdgpu_userq_funcs *userq_funcs;
> +	struct amdgpu_usermode_queue *queue;
> +	struct amdgpu_userq_mgr *uqm, *tmp;
> +	int queue_id;
> +	int ret = 0;
> +
> +	mutex_lock(&adev->userq_mutex);
> +	if (!adev->userq_halt)
> +		dev_warn(adev->dev, "userq scheduling already started!\n");
> +	adev->userq_halt = false;
> +	list_for_each_entry_safe(uqm, tmp, &adev->userq_mgr_list, list) {
> +		idr_for_each_entry(&uqm->userq_idr, queue, queue_id) {
> +			userq_funcs = adev->userq_funcs[queue->queue_type];
> +			ret |= userq_funcs->map(uqm, queue);
> +		}
> +	}
> +	mutex_unlock(&adev->userq_mutex);
> +	return ret;
> +}
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_userqueue.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_userqueue.h
> index 381b9c6f0573d..fd0542f60433b 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_userqueue.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_userqueue.h
> @@ -114,4 +114,7 @@ uint64_t amdgpu_userqueue_get_doorbell_index(struct amdgpu_userq_mgr *uq_mgr,
>   int amdgpu_userq_suspend(struct amdgpu_device *adev);
>   int amdgpu_userq_resume(struct amdgpu_device *adev);
>   
> +int amdgpu_userq_stop_sched(struct amdgpu_device *adev, u32 idx);
> +int amdgpu_userq_start_sched(struct amdgpu_device *adev, u32 idx);
> +
>   #endif