regmap: regcache-rbtree: Fix present bitmap resize

[ Upstream commit 328f494 ]

When inserting a new register into a block at the lower end the present
bitmap is currently shifted into the wrong direction. The effect of this is
that the bitmap becomes corrupted and registers which are present might be
reported as not present and vice versa.

Fix this by shifting left rather than right.

Fixes: 472fdec("regmap: rbtree: Reduce number of nodes, take 2")
Reported-by: Daniel Baluta <[email protected]>
Signed-off-by: Lars-Peter Clausen <[email protected]>
Signed-off-by: Mark Brown <[email protected]>
Cc: [email protected]
Signed-off-by: Sasha Levin <[email protected]>

drivers/base/regmap/regcache-rbtree.c

@@ -307,7 +307,7 @@ static int regcache_rbtree_insert_to_block(struct regmap *map,
 	if (pos == 0) {
 		memmove(blk + offset * map->cache_word_size,
 			blk, rbnode->blklen * map->cache_word_size);
-		bitmap_shift_right(present, present, offset, blklen);
+		bitmap_shift_left(present, present, offset, blklen);
 	}
 
 	/* update the rbnode block, its size and the base register */