blk-mq: split out tag initialization, support shared tags
Add a new blk_mq_tag_set structure that gets set up before we initialize
the queue. A single blk_mq_tag_set structure can be shared by multiple
queues.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Modular export of blk_mq_{alloc,free}_tagset added by me.
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/block/blk-mq-tag.h b/block/blk-mq-tag.h
index 947ba2c..b602e3f 100644
--- a/block/blk-mq-tag.h
+++ b/block/blk-mq-tag.h
@@ -1,7 +1,24 @@
#ifndef INT_BLK_MQ_TAG_H
#define INT_BLK_MQ_TAG_H
-struct blk_mq_tags;
+#include <linux/percpu_ida.h>
+
+/*
+ * Tag address space map.
+ */
+struct blk_mq_tags {
+ unsigned int nr_tags;
+ unsigned int nr_reserved_tags;
+ unsigned int nr_batch_move;
+ unsigned int nr_max_cache;
+
+ struct percpu_ida free_tags;
+ struct percpu_ida reserved_tags;
+
+ struct request **rqs;
+ struct list_head page_list;
+};
+
extern struct blk_mq_tags *blk_mq_init_tags(unsigned int nr_tags, unsigned int reserved_tags, int node);
extern void blk_mq_free_tags(struct blk_mq_tags *tags);
