drm/ttm: stop allocating a dummy resource for pipelined gutting

That should not be necessary any more when drivers should at least be
able to handle a move without a resource.
Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Acked-by: Nirmoy Das <nirmoy.das@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230130120636.63765-5-matthew.auld@intel.com

drivers/gpu/drm/ttm/ttm_bo_util.c

@@ -704,30 +704,23 @@ EXPORT_SYMBOL(ttm_bo_move_sync_cleanup);
  */
 int ttm_bo_pipeline_gutting(struct ttm_buffer_object *bo)
 {
-	static const struct ttm_place sys_mem = { .mem_type = TTM_PL_SYSTEM };
 	struct ttm_buffer_object *ghost;
-	struct ttm_resource *sys_res;
 	struct ttm_tt *ttm;
 	int ret;
 
-	ret = ttm_resource_alloc(bo, &sys_mem, &sys_res);
-	if (ret)
-		return ret;
-
 	/* If already idle, no need for ghost object dance. */
 	if (dma_resv_test_signaled(bo->base.resv, DMA_RESV_USAGE_BOOKKEEP)) {
 		if (!bo->ttm) {
 			/* See comment below about clearing. */
 			ret = ttm_tt_create(bo, true);
 			if (ret)
-				goto error_free_sys_mem;
+				return ret;
 		} else {
 			ttm_tt_unpopulate(bo->bdev, bo->ttm);
 			if (bo->type == ttm_bo_type_device)
 				ttm_tt_mark_for_clear(bo->ttm);
 		}
 		ttm_resource_free(bo, &bo->resource);
-		ttm_bo_assign_mem(bo, sys_res);
 		return 0;
 	}
 
@@ -744,7 +737,7 @@ int ttm_bo_pipeline_gutting(struct ttm_buffer_object *bo)
 	ret = ttm_tt_create(bo, true);
 	swap(bo->ttm, ttm);
 	if (ret)
-		goto error_free_sys_mem;
+		return ret;
 
 	ret = ttm_buffer_object_transfer(bo, &ghost);
 	if (ret)
@@ -760,13 +753,9 @@ int ttm_bo_pipeline_gutting(struct ttm_buffer_object *bo)
 	dma_resv_unlock(&ghost->base._resv);
 	ttm_bo_put(ghost);
 	bo->ttm = ttm;
-	ttm_bo_assign_mem(bo, sys_res);
 	return 0;
 
 error_destroy_tt:
 	ttm_tt_destroy(bo->bdev, ttm);
-
-error_free_sys_mem:
-	ttm_resource_free(bo, &sys_res);
 	return ret;
 }