block/blk-mq-tag.h

   1 #ifndef INT_BLK_MQ_TAG_H
   2 #define INT_BLK_MQ_TAG_H
   3
   4 enum {
   5         BT_WAIT_QUEUES  = 8,
   6         BT_WAIT_BATCH   = 8,
   7 };
   8
   9 struct bt_wait_state {
  10         atomic_t wait_cnt;
  11         wait_queue_head_t wait;
  12 } ____cacheline_aligned_in_smp;
  13
  14 #define TAG_TO_INDEX(bt, tag)   ((tag) >> (bt)->bits_per_word)
  15 #define TAG_TO_BIT(bt, tag)     ((tag) & ((1 << (bt)->bits_per_word) - 1))
  16
  17 struct blk_mq_bitmap {
  18         unsigned long word;
  19         unsigned long depth;
  20 } ____cacheline_aligned_in_smp;
  21
  22 struct blk_mq_bitmap_tags {
  23         unsigned int depth;
  24         unsigned int wake_cnt;
  25         unsigned int bits_per_word;
  26
  27         unsigned int map_nr;
  28         struct blk_mq_bitmap *map;
  29
  30         unsigned int wake_index;
  31         struct bt_wait_state *bs;
  32 };
  33
  34 /*
  35  * Tag address space map.
  36  */
  37 struct blk_mq_tags {
  38         unsigned int nr_tags;
  39         unsigned int nr_reserved_tags;
  40
  41         atomic_t active_queues;
  42
  43         struct blk_mq_bitmap_tags bitmap_tags;
  44         struct blk_mq_bitmap_tags breserved_tags;
  45
  46         struct request **rqs;
  47         struct list_head page_list;
  48 };
  49
  50
  51 extern struct blk_mq_tags *blk_mq_init_tags(unsigned int nr_tags, unsigned int reserved_tags, int node);
  52 extern void blk_mq_free_tags(struct blk_mq_tags *tags);
  53
  54 extern unsigned int blk_mq_get_tag(struct blk_mq_hw_ctx *hctx, unsigned int *last_tag, gfp_t gfp, bool reserved);
  55 extern void blk_mq_wait_for_tags(struct blk_mq_hw_ctx *hctx, bool reserved);
  56 extern void blk_mq_put_tag(struct blk_mq_hw_ctx *hctx, unsigned int tag, unsigned int *last_tag);
  57 extern void blk_mq_tag_busy_iter(struct blk_mq_tags *tags, void (*fn)(void *data, unsigned long *), void *data);
  58 extern bool blk_mq_has_free_tags(struct blk_mq_tags *tags);
  59 extern ssize_t blk_mq_tag_sysfs_show(struct blk_mq_tags *tags, char *page);
  60 extern void blk_mq_tag_init_last_tag(struct blk_mq_tags *tags, unsigned int *last_tag);
  61
  62 enum {
  63         BLK_MQ_TAG_CACHE_MIN    = 1,
  64         BLK_MQ_TAG_CACHE_MAX    = 64,
  65 };
  66
  67 enum {
  68         BLK_MQ_TAG_FAIL         = -1U,
  69         BLK_MQ_TAG_MIN          = BLK_MQ_TAG_CACHE_MIN,
  70         BLK_MQ_TAG_MAX          = BLK_MQ_TAG_FAIL - 1,
  71 };
  72
  73 extern bool __blk_mq_tag_busy(struct blk_mq_hw_ctx *);
  74 extern void __blk_mq_tag_idle(struct blk_mq_hw_ctx *);
  75
  76 static inline bool blk_mq_tag_busy(struct blk_mq_hw_ctx *hctx)
  77 {
  78         if (!(hctx->flags & BLK_MQ_F_TAG_SHARED))
  79                 return false;
  80
  81         return __blk_mq_tag_busy(hctx);
  82 }
  83
  84 static inline void blk_mq_tag_idle(struct blk_mq_hw_ctx *hctx)
  85 {
  86         if (!(hctx->flags & BLK_MQ_F_TAG_SHARED))
  87                 return;
  88
  89         __blk_mq_tag_idle(hctx);
  90 }
  91
  92 #endif