drm/ttm: Change ttm_tt page allocations to return errors

Explicitly return errors in ttm_tt_alloc_page_directory() and
ttm_dma_tt_alloc_page_directory() instead of relying on
further logic to detect errors.
Signed-off-by: Tom St Denis <tom.stdenis@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/ttm/ttm_tt.c

@@ -50,19 +50,25 @@
 /**
  * Allocates storage for pointers to the pages that back the ttm.
  */
-static void ttm_tt_alloc_page_directory(struct ttm_tt *ttm)
+static int ttm_tt_alloc_page_directory(struct ttm_tt *ttm)
 {
 	ttm->pages = kvmalloc_array(ttm->num_pages, sizeof(void*),
 			GFP_KERNEL | __GFP_ZERO);
+	if (!ttm->pages)
+		return -ENOMEM;
+	return 0;
 }
 
-static void ttm_dma_tt_alloc_page_directory(struct ttm_dma_tt *ttm)
+static int ttm_dma_tt_alloc_page_directory(struct ttm_dma_tt *ttm)
 {
 	ttm->ttm.pages = kvmalloc_array(ttm->ttm.num_pages,
 					  sizeof(*ttm->ttm.pages) +
 					  sizeof(*ttm->dma_address),
 					  GFP_KERNEL | __GFP_ZERO);
+	if (!ttm->ttm.pages)
+		return -ENOMEM;
 	ttm->dma_address = (void *) (ttm->ttm.pages + ttm->ttm.num_pages);
+	return 0;
 }
 
 #ifdef CONFIG_X86
@@ -197,8 +203,7 @@ int ttm_tt_init(struct ttm_tt *ttm, struct ttm_bo_device *bdev,
 	ttm->state = tt_unpopulated;
 	ttm->swap_storage = NULL;
 
-	ttm_tt_alloc_page_directory(ttm);
-	if (!ttm->pages) {
+	if (ttm_tt_alloc_page_directory(ttm)) {
 		ttm_tt_destroy(ttm);
 		pr_err("Failed allocating page table\n");
 		return -ENOMEM;
@@ -230,8 +235,7 @@ int ttm_dma_tt_init(struct ttm_dma_tt *ttm_dma, struct ttm_bo_device *bdev,
 	ttm->swap_storage = NULL;
 
 	INIT_LIST_HEAD(&ttm_dma->pages_list);
-	ttm_dma_tt_alloc_page_directory(ttm_dma);
-	if (!ttm->pages) {
+	if (ttm_dma_tt_alloc_page_directory(ttm_dma)) {
 		ttm_tt_destroy(ttm);
 		pr_err("Failed allocating page table\n");
 		return -ENOMEM;