1#ifndef INT_BLK_MQ_TAG_H
2#define INT_BLK_MQ_TAG_H
3
4#include "blk-mq.h"
5
6enum {
7	BT_WAIT_QUEUES	= 8,
8	BT_WAIT_BATCH	= 8,
9};
10
11struct bt_wait_state {
12	atomic_t wait_cnt;
13	wait_queue_head_t wait;
14} ____cacheline_aligned_in_smp;
15
16#define TAG_TO_INDEX(bt, tag)	((tag) >> (bt)->bits_per_word)
17#define TAG_TO_BIT(bt, tag)	((tag) & ((1 << (bt)->bits_per_word) - 1))
18
19struct blk_mq_bitmap_tags {
20	unsigned int depth;
21	unsigned int wake_cnt;
22	unsigned int bits_per_word;
23
24	unsigned int map_nr;
25	struct blk_align_bitmap *map;
26
27	atomic_t wake_index;
28	struct bt_wait_state *bs;
29};
30
31/*
32 * Tag address space map.
33 */
34struct blk_mq_tags {
35	unsigned int nr_tags;
36	unsigned int nr_reserved_tags;
37
38	atomic_t active_queues;
39
40	struct blk_mq_bitmap_tags bitmap_tags;
41	struct blk_mq_bitmap_tags breserved_tags;
42
43	struct request **rqs;
44	struct list_head page_list;
45
46	int alloc_policy;
47	cpumask_var_t cpumask;
48};
49
50
51extern struct blk_mq_tags *blk_mq_init_tags(unsigned int nr_tags, unsigned int reserved_tags, int node, int alloc_policy);
52extern void blk_mq_free_tags(struct blk_mq_tags *tags);
53
54extern unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data);
55extern void blk_mq_put_tag(struct blk_mq_hw_ctx *hctx, unsigned int tag, unsigned int *last_tag);
56extern bool blk_mq_has_free_tags(struct blk_mq_tags *tags);
57extern ssize_t blk_mq_tag_sysfs_show(struct blk_mq_tags *tags, char *page);
58extern void blk_mq_tag_init_last_tag(struct blk_mq_tags *tags, unsigned int *last_tag);
59extern int blk_mq_tag_update_depth(struct blk_mq_tags *tags, unsigned int depth);
60extern void blk_mq_tag_wakeup_all(struct blk_mq_tags *tags, bool);
61void blk_mq_queue_tag_busy_iter(struct request_queue *q, busy_iter_fn *fn,
62		void *priv);
63
64enum {
65	BLK_MQ_TAG_CACHE_MIN	= 1,
66	BLK_MQ_TAG_CACHE_MAX	= 64,
67};
68
69enum {
70	BLK_MQ_TAG_FAIL		= -1U,
71	BLK_MQ_TAG_MIN		= BLK_MQ_TAG_CACHE_MIN,
72	BLK_MQ_TAG_MAX		= BLK_MQ_TAG_FAIL - 1,
73};
74
75extern bool __blk_mq_tag_busy(struct blk_mq_hw_ctx *);
76extern void __blk_mq_tag_idle(struct blk_mq_hw_ctx *);
77
78static inline bool blk_mq_tag_busy(struct blk_mq_hw_ctx *hctx)
79{
80	if (!(hctx->flags & BLK_MQ_F_TAG_SHARED))
81		return false;
82
83	return __blk_mq_tag_busy(hctx);
84}
85
86static inline void blk_mq_tag_idle(struct blk_mq_hw_ctx *hctx)
87{
88	if (!(hctx->flags & BLK_MQ_F_TAG_SHARED))
89		return;
90
91	__blk_mq_tag_idle(hctx);
92}
93
94/*
95 * This helper should only be used for flush request to share tag
96 * with the request cloned from, and both the two requests can't be
97 * in flight at the same time. The caller has to make sure the tag
98 * can't be freed.
99 */
100static inline void blk_mq_tag_set_rq(struct blk_mq_hw_ctx *hctx,
101		unsigned int tag, struct request *rq)
102{
103	hctx->tags->rqs[tag] = rq;
104}
105
106#endif
107