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 request **static_rqs;
  20         struct list_head page_list;
  21 };
  22
  23
  24 extern struct blk_mq_tags *blk_mq_init_tags(unsigned int nr_tags, unsigned int reserved_tags, int node, int alloc_policy);
  25 extern void blk_mq_free_tags(struct blk_mq_tags *tags);
  26
  27 extern unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data);
  28 extern 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);
  30 extern bool blk_mq_has_free_tags(struct blk_mq_tags *tags);
  31 extern 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);
  34 extern void blk_mq_tag_wakeup_all(struct blk_mq_tags *tags, bool);
  35 void blk_mq_queue_tag_busy_iter(struct request_queue *q, busy_iter_fn *fn,
  36                 void *priv);
  37
  38 static 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
  46 enum {
  47         BLK_MQ_TAG_CACHE_MIN    = 1,
  48         BLK_MQ_TAG_CACHE_MAX    = 64,
  49 };
  50
  51 enum {
  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
  57 extern bool __blk_mq_tag_busy(struct blk_mq_hw_ctx *);
  58 extern void __blk_mq_tag_idle(struct blk_mq_hw_ctx *);
  59
  60 static 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
  68 static 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  */
  82 static 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
  88 static 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