--- zzzz-none-000/linux-3.10.107/drivers/gpu/drm/ttm/ttm_tt.c	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/drivers/gpu/drm/ttm/ttm_tt.c	2021-02-04 17:41:59.000000000 +0000
@@ -55,9 +55,12 @@
 
 static void ttm_dma_tt_alloc_page_directory(struct ttm_dma_tt *ttm)
 {
-	ttm->ttm.pages = drm_calloc_large(ttm->ttm.num_pages, sizeof(void*));
-	ttm->dma_address = drm_calloc_large(ttm->ttm.num_pages,
-					    sizeof(*ttm->dma_address));
+	ttm->ttm.pages = drm_calloc_large(ttm->ttm.num_pages,
+					  sizeof(*ttm->ttm.pages) +
+					  sizeof(*ttm->dma_address) +
+					  sizeof(*ttm->cpu_address));
+	ttm->cpu_address = (void *) (ttm->ttm.pages + ttm->ttm.num_pages);
+	ttm->dma_address = (void *) (ttm->cpu_address + ttm->ttm.num_pages);
 }
 
 #ifdef CONFIG_X86
@@ -170,9 +173,8 @@
 		ttm_tt_unbind(ttm);
 	}
 
-	if (ttm->state == tt_unbound) {
-		ttm->bdev->driver->ttm_tt_unpopulate(ttm);
-	}
+	if (ttm->state == tt_unbound)
+		ttm_tt_unpopulate(ttm);
 
 	if (!(ttm->page_flags & TTM_PAGE_FLAG_PERSISTENT_SWAP) &&
 	    ttm->swap_storage)
@@ -229,7 +231,7 @@
 
 	INIT_LIST_HEAD(&ttm_dma->pages_list);
 	ttm_dma_tt_alloc_page_directory(ttm_dma);
-	if (!ttm->pages || !ttm_dma->dma_address) {
+	if (!ttm->pages) {
 		ttm_tt_destroy(ttm);
 		pr_err("Failed allocating page table\n");
 		return -ENOMEM;
@@ -244,7 +246,7 @@
 
 	drm_free_large(ttm->pages);
 	ttm->pages = NULL;
-	drm_free_large(ttm_dma->dma_address);
+	ttm_dma->cpu_address = NULL;
 	ttm_dma->dma_address = NULL;
 }
 EXPORT_SYMBOL(ttm_dma_tt_fini);
@@ -338,7 +340,7 @@
 		swap_storage = shmem_file_setup("ttm swap",
 						ttm->num_pages << PAGE_SHIFT,
 						0);
-		if (unlikely(IS_ERR(swap_storage))) {
+		if (IS_ERR(swap_storage)) {
 			pr_err("Failed allocating swap storage\n");
 			return PTR_ERR(swap_storage);
 		}
@@ -352,7 +354,7 @@
 		if (unlikely(from_page == NULL))
 			continue;
 		to_page = shmem_read_mapping_page(swap_space, i);
-		if (unlikely(IS_ERR(to_page))) {
+		if (IS_ERR(to_page)) {
 			ret = PTR_ERR(to_page);
 			goto out_err;
 		}
@@ -362,7 +364,7 @@
 		page_cache_release(to_page);
 	}
 
-	ttm->bdev->driver->ttm_tt_unpopulate(ttm);
+	ttm_tt_unpopulate(ttm);
 	ttm->swap_storage = swap_storage;
 	ttm->page_flags |= TTM_PAGE_FLAG_SWAPPED;
 	if (persistent_swap_storage)
@@ -375,3 +377,26 @@
 
 	return ret;
 }
+
+static void ttm_tt_clear_mapping(struct ttm_tt *ttm)
+{
+	pgoff_t i;
+	struct page **page = ttm->pages;
+
+	if (ttm->page_flags & TTM_PAGE_FLAG_SG)
+		return;
+
+	for (i = 0; i < ttm->num_pages; ++i) {
+		(*page)->mapping = NULL;
+		(*page++)->index = 0;
+	}
+}
+
+void ttm_tt_unpopulate(struct ttm_tt *ttm)
+{
+	if (ttm->state == tt_unpopulated)
+		return;
+
+	ttm_tt_clear_mapping(ttm);
+	ttm->bdev->driver->ttm_tt_unpopulate(ttm);
+}