1#ifndef INT_BLK_MQ_TAG_H
 2#define INT_BLK_MQ_TAG_H
 3
 4#include "blk-mq.h"
 5
 6/*
 7 * Tag address space map.
 8 */
 9struct blk_mq_tags {
10	unsigned int nr_tags;
11	unsigned int nr_reserved_tags;
12
13	atomic_t active_queues;
14
15	struct sbitmap_queue bitmap_tags;
16	struct sbitmap_queue breserved_tags;
17
18	struct request **rqs;
19	struct list_head page_list;
20};
21
22
23extern struct blk_mq_tags *blk_mq_init_tags(unsigned int nr_tags, unsigned int reserved_tags, int node, int alloc_policy);
24extern void blk_mq_free_tags(struct blk_mq_tags *tags);
25
26extern unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data);
27extern void blk_mq_put_tag(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx,
28			   unsigned int tag);
29extern bool blk_mq_has_free_tags(struct blk_mq_tags *tags);
30extern ssize_t blk_mq_tag_sysfs_show(struct blk_mq_tags *tags, char *page);
31extern int blk_mq_tag_update_depth(struct blk_mq_tags *tags, unsigned int depth);
32extern void blk_mq_tag_wakeup_all(struct blk_mq_tags *tags, bool);
33void blk_mq_queue_tag_busy_iter(struct request_queue *q, busy_iter_fn *fn,
34		void *priv);
35
36static inline struct sbq_wait_state *bt_wait_ptr(struct sbitmap_queue *bt,
37						 struct blk_mq_hw_ctx *hctx)
38{
39	if (!hctx)
40		return &bt->ws[0];
41	return sbq_wait_ptr(bt, &hctx->wait_index);
42}
43
44enum {
45	BLK_MQ_TAG_CACHE_MIN	= 1,
46	BLK_MQ_TAG_CACHE_MAX	= 64,
47};
48
49enum {
50	BLK_MQ_TAG_FAIL		= -1U,
51	BLK_MQ_TAG_MIN		= BLK_MQ_TAG_CACHE_MIN,
52	BLK_MQ_TAG_MAX		= BLK_MQ_TAG_FAIL - 1,
53};
54
55extern bool __blk_mq_tag_busy(struct blk_mq_hw_ctx *);
56extern void __blk_mq_tag_idle(struct blk_mq_hw_ctx *);
57
58static inline bool blk_mq_tag_busy(struct blk_mq_hw_ctx *hctx)
59{
60	if (!(hctx->flags & BLK_MQ_F_TAG_SHARED))
61		return false;
62
63	return __blk_mq_tag_busy(hctx);
64}
65
66static inline void blk_mq_tag_idle(struct blk_mq_hw_ctx *hctx)
67{
68	if (!(hctx->flags & BLK_MQ_F_TAG_SHARED))
69		return;
70
71	__blk_mq_tag_idle(hctx);
72}
73
74/*
75 * This helper should only be used for flush request to share tag
76 * with the request cloned from, and both the two requests can't be
77 * in flight at the same time. The caller has to make sure the tag
78 * can't be freed.
79 */
80static inline void blk_mq_tag_set_rq(struct blk_mq_hw_ctx *hctx,
81		unsigned int tag, struct request *rq)
82{
83	hctx->tags->rqs[tag] = rq;
84}
85
86#endif