drm/ttm: add helper structures for bulk moves on lru list

Add bulk move pos to store the pointer of first and last buffer object.
The list in between will be bulk moved on lru list.
Signed-off-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Huang Rui <ray.huang@amd.com>
Tested-by: Mike Lothian <mike@fireburn.co.uk>
Tested-by: Dieter Nützel <Dieter@nuetzel-hh.de>
Acked-by: Chunming Zhou <david1.zhou@amd.com>
Reviewed-by: Junwei Zhang <Jerry.Zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

include/drm/ttm/ttm_bo_driver.h

@@ -490,6 +490,34 @@ struct ttm_bo_device {
 	bool no_retry;
 };
 
+/**
+ * struct ttm_lru_bulk_move_pos
+ *
+ * @first: first BO in the bulk move range
+ * @last: last BO in the bulk move range
+ *
+ * Positions for a lru bulk move.
+ */
+struct ttm_lru_bulk_move_pos {
+	struct ttm_buffer_object *first;
+	struct ttm_buffer_object *last;
+};
+
+/**
+ * struct ttm_lru_bulk_move
+ *
+ * @tt: first/last lru entry for BOs in the TT domain
+ * @vram: first/last lru entry for BOs in the VRAM domain
+ * @swap: first/last lru entry for BOs on the swap list
+ *
+ * Helper structure for bulk moves on the LRU list.
+ */
+struct ttm_lru_bulk_move {
+	struct ttm_lru_bulk_move_pos tt[TTM_MAX_BO_PRIORITY];
+	struct ttm_lru_bulk_move_pos vram[TTM_MAX_BO_PRIORITY];
+	struct ttm_lru_bulk_move_pos swap[TTM_MAX_BO_PRIORITY];
+};
+
 /**
  * ttm_flag_masked
  *