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 request **static_rqs;
  20        struct list_head page_list;
  21};
  22
  23
  24extern struct blk_mq_tags *blk_mq_init_tags(unsigned int nr_tags, unsigned int reserved_tags, int node, int alloc_policy);
  25extern void blk_mq_free_tags(struct blk_mq_tags *tags);
  26
  27extern unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data);
  28extern void blk_mq_put_tag(struct blk_mq_hw_ctx *hctx, struct blk_mq_tags *tags,
  29                           struct blk_mq_ctx *ctx, unsigned int tag);
  30extern bool blk_mq_has_free_tags(struct blk_mq_tags *tags);
  31extern int blk_mq_tag_update_depth(struct blk_mq_hw_ctx *hctx,
  32                                        struct blk_mq_tags **tags,
  33                                        unsigned int depth, bool can_grow);
  34extern void blk_mq_tag_wakeup_all(struct blk_mq_tags *tags, bool);
  35void blk_mq_queue_tag_busy_iter(struct request_queue *q, busy_iter_fn *fn,
  36                void *priv);
  37
  38static inline struct sbq_wait_state *bt_wait_ptr(struct sbitmap_queue *bt,
  39                                                 struct blk_mq_hw_ctx *hctx)
  40{
  41        if (!hctx)
  42                return &bt->ws[0];
  43        return sbq_wait_ptr(bt, &hctx->wait_index);
  44}
  45
  46enum {
  47        BLK_MQ_TAG_CACHE_MIN    = 1,
  48        BLK_MQ_TAG_CACHE_MAX    = 64,
  49};
  50
  51enum {
  52        BLK_MQ_TAG_FAIL         = -1U,
  53        BLK_MQ_TAG_MIN          = BLK_MQ_TAG_CACHE_MIN,
  54        BLK_MQ_TAG_MAX          = BLK_MQ_TAG_FAIL - 1,
  55};
  56
  57extern bool __blk_mq_tag_busy(struct blk_mq_hw_ctx *);
  58extern void __blk_mq_tag_idle(struct blk_mq_hw_ctx *);
  59
  60static inline bool blk_mq_tag_busy(struct blk_mq_hw_ctx *hctx)
  61{
  62        if (!(hctx->flags & BLK_MQ_F_TAG_SHARED))
  63                return false;
  64
  65        return __blk_mq_tag_busy(hctx);
  66}
  67
  68static inline void blk_mq_tag_idle(struct blk_mq_hw_ctx *hctx)
  69{
  70        if (!(hctx->flags & BLK_MQ_F_TAG_SHARED))
  71                return;
  72
  73        __blk_mq_tag_idle(hctx);
  74}
  75
  76/*
  77 * This helper should only be used for flush request to share tag
  78 * with the request cloned from, and both the two requests can't be
  79 * in flight at the same time. The caller has to make sure the tag
  80 * can't be freed.
  81 */
  82static inline void blk_mq_tag_set_rq(struct blk_mq_hw_ctx *hctx,
  83                unsigned int tag, struct request *rq)
  84{
  85        hctx->tags->rqs[tag] = rq;
  86}
  87
  88static inline bool blk_mq_tag_is_reserved(struct blk_mq_tags *tags,
  89                                          unsigned int tag)
  90{
  91        return tag < tags->nr_reserved_tags;
  92}
  93
  94#endif
  95