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  */
   9 struct 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
  23 extern struct blk_mq_tags *blk_mq_init_tags(unsigned int nr_tags, unsigned int reserved_tags, int node, int alloc_policy);
  24 extern void blk_mq_free_tags(struct blk_mq_tags *tags);
  25
  26 extern unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data);
  27 extern void blk_mq_put_tag(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx,
  28                            unsigned int tag);
  29 extern bool blk_mq_has_free_tags(struct blk_mq_tags *tags);
  30 extern ssize_t blk_mq_tag_sysfs_show(struct blk_mq_tags *tags, char *page);
  31 extern int blk_mq_tag_update_depth(struct blk_mq_tags *tags, unsigned int depth);
  32 extern void blk_mq_tag_wakeup_all(struct blk_mq_tags *tags, bool);
  33 void blk_mq_queue_tag_busy_iter(struct request_queue *q, busy_iter_fn *fn,
  34                 void *priv);
  35
  36 static 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
  44 enum {
  45         BLK_MQ_TAG_CACHE_MIN    = 1,
  46         BLK_MQ_TAG_CACHE_MAX    = 64,
  47 };
  48
  49 enum {
  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
  55 extern bool __blk_mq_tag_busy(struct blk_mq_hw_ctx *);
  56 extern void __blk_mq_tag_idle(struct blk_mq_hw_ctx *);
  57
  58 static 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
  66 static 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  */
  80 static 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