drm/amdgpu: Don't move pinned BOs

The purpose of pinning is to prevent a buffer from moving.
Reviewed-by: NChristian König <christian.koenig@amd.com>
Tested-by: NRex Zhu <Rex.Zhu@amd.com>
Signed-off-by: NMichel Dänzer <michel.daenzer@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

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

@@ -608,6 +608,10 @@ int amdgpu_bo_fault_reserve_notify(struct ttm_buffer_object *bo)
 	if ((offset + size) <= adev->mc.visible_vram_size)
 		return 0;
 
+	/* Can't move a pinned BO to visible VRAM */
+	if (abo->pin_count > 0)
+		return -EINVAL;
+
 	/* hurrah the memory is not visible ! */
 	amdgpu_ttm_placement_from_domain(abo, AMDGPU_GEM_DOMAIN_VRAM);
 	lpfn =	adev->mc.visible_vram_size >> PAGE_SHIFT;

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

@@ -384,9 +384,15 @@ static int amdgpu_bo_move(struct ttm_buffer_object *bo,
 			struct ttm_mem_reg *new_mem)
 {
 	struct amdgpu_device *adev;
+	struct amdgpu_bo *abo;
 	struct ttm_mem_reg *old_mem = &bo->mem;
 	int r;
 
+	/* Can't move a pinned BO */
+	abo = container_of(bo, struct amdgpu_bo, tbo);
+	if (WARN_ON_ONCE(abo->pin_count > 0))
+		return -EINVAL;
+
 	adev = amdgpu_get_adev(bo->bdev);
 	if (old_mem->mem_type == TTM_PL_SYSTEM && bo->ttm == NULL) {
 		amdgpu_move_null(bo, new_mem);