drm/ttm: Correctly set page mapping and -index members

Needed for some vm operations; most notably unmap_mapping_range() with
even_cows = 0.

Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Brian Paul <brianp@vmware.com>

1 files changed, 23 insertions, 4 deletions

diff --git a/drivers/gpu/drm/ttm/ttm_tt.c b/drivers/gpu/drm/ttm/ttm_tt.c
index 210d50365162..9af99084b344 100644
--- a/drivers/gpu/drm/ttm/ttm_tt.c
+++ b/drivers/gpu/drm/ttm/ttm_tt.c
@@ -170,9 +170,8 @@ void ttm_tt_destroy(struct ttm_tt *ttm)
                 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)
@@ -362,7 +361,7 @@ int ttm_tt_swapout(struct ttm_tt *ttm, struct file *persistent_swap_storage)
                 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 +374,23 @@ out_err:
 
         return ret;
 }
+
+static void ttm_tt_clear_mapping(struct ttm_tt *ttm)
+{
+        pgoff_t i;
+        struct page **page = ttm->pages;
+
+        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);
+}