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