Commit b8e6d3f6 authored by Shashank Sharma's avatar Shashank Sharma Committed by Alex Deucher
Browse files

drm/amdgpu: handle eviction fence race 



The eviction process can get into a race condition between the eviction
fence suspend work (which replaces the old fence with new) and kms_close
(which destroys the fence and doesn't expect a new one).

This patch:
- adds a flag to indicate that fd is closing, so fence replacement is
  not required (evf_mgr->fd_closing)
- adds a flush_work() during the ev_fence_destroy routine

V2: Addressed review comments from Christian:
    - Do not use mutex to sync
    - Use flush_work and wait for suspend_work to be done

V3: Fixed state machine for queue->active, which adds into race between
    suspend/resume and queue ops

Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Christian König <christian.koenig@amd.com>
Reviewed-by: default avatarChristian König <christian.koenig@amd.com>
Signed-off-by: default avatarShashank Sharma <shashank.sharma@amd.com>
Signed-off-by: default avatarArvind Yadav <arvind.yadav@amd.com>
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
parent 44cfdf36

drivers/gpu/drm/amd/amdgpu/amdgpu_eviction_fence.c

+7 −0
Original line number Diff line number Diff line
@@ -117,6 +117,10 @@ amdgpu_eviction_fence_suspend_worker(struct work_struct *work) 
	/* Signal old eviction fence */

	amdgpu_eviction_fence_signal(evf_mgr);



	/* Do not replace eviction fence is fd is getting closed */

	if (evf_mgr->fd_closing)

		return;



	/* Prepare the objects to replace eviction fence */

	drm_exec_init(&exec, DRM_EXEC_IGNORE_DUPLICATES, 0);

	drm_exec_until_all_locked(&exec) {
@@ -199,6 +203,9 @@ void amdgpu_eviction_fence_destroy(struct amdgpu_eviction_fence_mgr *evf_mgr) 
{

	struct amdgpu_eviction_fence *ev_fence;



	/* Wait for any pending work to execute */

	flush_delayed_work(&evf_mgr->suspend_work);



	spin_lock(&evf_mgr->ev_fence_lock);

	ev_fence = evf_mgr->ev_fence;

	spin_unlock(&evf_mgr->ev_fence_lock);

drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c

+3 −1
Original line number Diff line number Diff line
@@ -1490,10 +1490,12 @@ void amdgpu_driver_postclose_kms(struct drm_device *dev, 
		amdgpu_bo_unreserve(pd);

	}



	fpriv->evf_mgr.fd_closing = true;

	amdgpu_userq_mgr_fini(&fpriv->userq_mgr);

	amdgpu_eviction_fence_destroy(&fpriv->evf_mgr);



	amdgpu_ctx_mgr_fini(&fpriv->ctx_mgr);

	amdgpu_vm_fini(adev, &fpriv->vm);

	amdgpu_userq_mgr_fini(&fpriv->userq_mgr);



	if (pasid)

		amdgpu_pasid_free_delayed(pd->tbo.base.resv, pasid);

drivers/gpu/drm/amd/amdgpu/amdgpu_userqueue.c

+2 −1
Original line number Diff line number Diff line
@@ -614,9 +614,10 @@ void amdgpu_userq_mgr_fini(struct amdgpu_userq_mgr *userq_mgr) 


	cancel_delayed_work(&userq_mgr->resume_work);



	mutex_lock(&userq_mgr->userq_mutex);

	idr_for_each_entry(&userq_mgr->userq_idr, queue, queue_id)

		amdgpu_userqueue_cleanup(userq_mgr, queue, queue_id);



	idr_destroy(&userq_mgr->userq_idr);

	mutex_unlock(&userq_mgr->userq_mutex);

	mutex_destroy(&userq_mgr->userq_mutex);

}

drivers/gpu/drm/amd/amdgpu/mes_v11_0_userqueue.c

+5 −4
Original line number Diff line number Diff line
@@ -139,6 +139,7 @@ static int mes_v11_0_userq_map(struct amdgpu_userq_mgr *uq_mgr, 
		return r;

	}



	queue->queue_active = true;

	DRM_DEBUG_DRIVER("Queue (doorbell:%d) mapped successfully\n", userq_props->doorbell_index);

	return 0;

}
@@ -160,6 +161,7 @@ static void mes_v11_0_userq_unmap(struct amdgpu_userq_mgr *uq_mgr, 
	amdgpu_mes_unlock(&adev->mes);

	if (r)

		DRM_ERROR("Failed to unmap queue in HW, err (%d)\n", r);

	queue->queue_active = false;

}



static int mes_v11_0_userq_create_ctx_space(struct amdgpu_userq_mgr *uq_mgr,
@@ -331,7 +333,6 @@ static int mes_v11_0_userq_mqd_create(struct amdgpu_userq_mgr *uq_mgr, 
		goto free_ctx;

	}



	queue->queue_active = true;

	return 0;



free_ctx:
@@ -350,12 +351,12 @@ static void 
mes_v11_0_userq_mqd_destroy(struct amdgpu_userq_mgr *uq_mgr,

			    struct amdgpu_usermode_queue *queue)

{

	if (queue->queue_active)

		mes_v11_0_userq_unmap(uq_mgr, queue);

	amdgpu_bo_unref(&queue->wptr_obj.obj);



	amdgpu_userqueue_destroy_object(uq_mgr, &queue->fw_obj);

	kfree(queue->userq_prop);

	amdgpu_userqueue_destroy_object(uq_mgr, &queue->mqd);

	queue->queue_active = false;

}



static int mes_v11_0_userq_suspend(struct amdgpu_userq_mgr *uq_mgr,