diff --git a/include/drm/ttm/ttm_bo_api.h b/include/drm/ttm/ttm_bo_api.h
index cd22ab4..99dc521 100644
--- a/include/drm/ttm/ttm_bo_api.h
+++ b/include/drm/ttm/ttm_bo_api.h
@@ -245,14 +245,15 @@
  * premapped region.
  */
 
+#define TTM_BO_MAP_IOMEM_MASK 0x80
 struct ttm_bo_kmap_obj {
 	void *virtual;
 	struct page *page;
 	enum {
-		ttm_bo_map_iomap,
-		ttm_bo_map_vmap,
-		ttm_bo_map_kmap,
-		ttm_bo_map_premapped,
+		ttm_bo_map_iomap        = 1 | TTM_BO_MAP_IOMEM_MASK,
+		ttm_bo_map_vmap         = 2,
+		ttm_bo_map_kmap         = 3,
+		ttm_bo_map_premapped    = 4 | TTM_BO_MAP_IOMEM_MASK,
 	} bo_kmap_type;
 };
 
@@ -522,8 +523,7 @@
 static inline void *ttm_kmap_obj_virtual(struct ttm_bo_kmap_obj *map,
 					 bool *is_iomem)
 {
-	*is_iomem = (map->bo_kmap_type == ttm_bo_map_iomap ||
-		     map->bo_kmap_type == ttm_bo_map_premapped);
+	*is_iomem = !!(map->bo_kmap_type & TTM_BO_MAP_IOMEM_MASK);
 	return map->virtual;
 }