LXR linux/block/blk-mq-tag.h

   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
  87