drm/ttm: set page mapping during allocation

To aid debugging set the page mapping during allocation instead of
during VM faults.
Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Roger He <Hongbo.He@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/ttm/ttm_bo_vm.c

@@ -257,7 +257,6 @@ static int ttm_bo_vm_fault(struct vm_fault *vmf)
 			} else if (unlikely(!page)) {
 				break;
 			}
-			page->mapping = vma->vm_file->f_mapping;
 			page->index = drm_vma_node_start(&bo->vma_node) +
 				page_offset;
 			pfn = page_to_pfn(page);

drivers/gpu/drm/ttm/ttm_tt.c

@@ -392,12 +392,28 @@ int ttm_tt_swapout(struct ttm_tt *ttm, struct file *persistent_swap_storage)
 	return ret;
 }
 
+static void ttm_tt_add_mapping(struct ttm_tt *ttm)
+{
+	pgoff_t i;
+
+	if (ttm->page_flags & TTM_PAGE_FLAG_SG)
+		return;
+
+	for (i = 0; i < ttm->num_pages; ++i)
+		ttm->pages[i]->mapping = ttm->bdev->dev_mapping;
+}
+
 int ttm_tt_populate(struct ttm_tt *ttm, struct ttm_operation_ctx *ctx)
 {
+	int ret;
+
 	if (ttm->state != tt_unpopulated)
 		return 0;
 
-	return ttm->bdev->driver->ttm_tt_populate(ttm, ctx);
+	ret = ttm->bdev->driver->ttm_tt_populate(ttm, ctx);
+	if (!ret)
+		ttm_tt_add_mapping(ttm);
+	return ret;
 }
 
 static void ttm_tt_clear_mapping(struct ttm_tt *ttm)