drm/amdgpu: fix holding mn_lock while allocating memory

We can't hold the mn_lock while allocating memory.
Signed-off-by: Christian König <christian.koenig@amd.com>
Acked-by: Chunming Zhou <david1.zhou@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -1194,26 +1194,24 @@ static int amdgpu_cs_submit(struct amdgpu_cs_parser *p,
 
 	int r;
 
+	job = p->job;
+	p->job = NULL;
+
+	r = drm_sched_job_init(&job->base, entity, p->filp);
+	if (r)
+		goto error_unlock;
+
+	/* No memory allocation is allowed while holding the mn lock */
 	amdgpu_mn_lock(p->mn);
 	amdgpu_bo_list_for_each_userptr_entry(e, p->bo_list) {
 		struct amdgpu_bo *bo = e->robj;
 
 		if (amdgpu_ttm_tt_userptr_needs_pages(bo->tbo.ttm)) {
-			amdgpu_mn_unlock(p->mn);
-			return -ERESTARTSYS;
+			r = -ERESTARTSYS;
+			goto error_abort;
 		}
 	}
 
-	job = p->job;
-	p->job = NULL;
-
-	r = drm_sched_job_init(&job->base, entity, p->filp);
-	if (r) {
-		amdgpu_job_free(job);
-		amdgpu_mn_unlock(p->mn);
-		return r;
-	}
-
 	job->owner = p->filp;
 	p->fence = dma_fence_get(&job->base.s_fence->finished);
 
@@ -1243,6 +1241,15 @@ static int amdgpu_cs_submit(struct amdgpu_cs_parser *p,
 	amdgpu_mn_unlock(p->mn);
 
 	return 0;
+
+error_abort:
+	dma_fence_put(&job->base.s_fence->finished);
+	job->base.s_fence = NULL;
+
+error_unlock:
+	amdgpu_job_free(job);
+	amdgpu_mn_unlock(p->mn);
+	return r;
 }
 
 int amdgpu_cs_ioctl(struct drm_device *dev, void *data, struct drm_file *filp)