diff --git a/block/blk-mq.c b/block/blk-mq.c
index c2777970f28bd3188c5fc033116292c2ed290d50..3a560a4db0b4047f1d5c295208aaeb02fb69b328 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -1130,12 +1130,7 @@ static void blk_mq_free_rq_map(struct blk_mq_tag_set *set,
 
 static size_t order_to_size(unsigned int order)
 {
-	size_t ret = PAGE_SIZE;
-
-	while (order--)
-		ret *= 2;
-
-	return ret;
+	return (size_t)PAGE_SIZE << order;
 }
 
 static struct blk_mq_tags *blk_mq_init_rq_map(struct blk_mq_tag_set *set,