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