linux/block/blk-mq-tag.h
Christoph Hellwig 24d2f90309 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>
2014-04-15 14:18:02 -06:00

45 lines
1.2 KiB
C

#ifndef INT_BLK_MQ_TAG_H
#define INT_BLK_MQ_TAG_H
#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);
extern unsigned int blk_mq_get_tag(struct blk_mq_tags *tags, gfp_t gfp, bool reserved);
extern void blk_mq_wait_for_tags(struct blk_mq_tags *tags);
extern void blk_mq_put_tag(struct blk_mq_tags *tags, unsigned int tag);
extern void blk_mq_tag_busy_iter(struct blk_mq_tags *tags, void (*fn)(void *data, unsigned long *), void *data);
extern bool blk_mq_has_free_tags(struct blk_mq_tags *tags);
extern ssize_t blk_mq_tag_sysfs_show(struct blk_mq_tags *tags, char *page);
enum {
BLK_MQ_TAG_CACHE_MIN = 1,
BLK_MQ_TAG_CACHE_MAX = 64,
};
enum {
BLK_MQ_TAG_FAIL = -1U,
BLK_MQ_TAG_MIN = BLK_MQ_TAG_CACHE_MIN,
BLK_MQ_TAG_MAX = BLK_MQ_TAG_FAIL - 1,
};
#endif