blk-mq: add blk_mq_stop_hw_queues

Add a helper to iterate over all hw queues and stop them.  This is useful
for driver that implement PM suspend functionality.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Modified to just call blk_mq_stop_hw_queue() by Jens.

Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/block/blk-mq.c b/block/blk-mq.c
index f21ec96..ac804c6 100644 (file)
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -672,6 +672,16 @@ void blk_mq_stop_hw_queue(struct blk_mq_hw_ctx *hctx)
 }
 EXPORT_SYMBOL(blk_mq_stop_hw_queue);
 
+void blk_mq_stop_hw_queues(struct request_queue *q)
+{
+       struct blk_mq_hw_ctx *hctx;
+       int i;
+
+       queue_for_each_hw_ctx(q, hctx, i)
+               blk_mq_stop_hw_queue(hctx);
+}
+EXPORT_SYMBOL(blk_mq_stop_hw_queues);
+
 void blk_mq_start_hw_queue(struct blk_mq_hw_ctx *hctx)
 {
        clear_bit(BLK_MQ_S_STOPPED, &hctx->state);

diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index 746042f..3368b97 100644 (file)
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -136,6 +136,7 @@ void blk_mq_end_io(struct request *rq, int error);
 
 void blk_mq_stop_hw_queue(struct blk_mq_hw_ctx *hctx);
 void blk_mq_start_hw_queue(struct blk_mq_hw_ctx *hctx);
+void blk_mq_stop_hw_queues(struct request_queue *q);
 void blk_mq_start_stopped_hw_queues(struct request_queue *q);
 
 /*