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 enum {
   7         BT_WAIT_QUEUES  = 8,
   8         BT_WAIT_BATCH   = 8,
   9 };
  10
  11 struct bt_wait_state {
  12         atomic_t wait_cnt;
  13         wait_queue_head_t wait;
  14 } ____cacheline_aligned_in_smp;
  15
  16 #define TAG_TO_INDEX(bt, tag)   ((tag) >> (bt)->bits_per_word)
  17 #define TAG_TO_BIT(bt, tag)     ((tag) & ((1 << (bt)->bits_per_word) - 1))
  18
  19 struct blk_mq_bitmap_tags {
  20         unsigned int depth;
  21         unsigned int wake_cnt;
  22         unsigned int bits_per_word;
  23
  24         unsigned int map_nr;
  25         struct blk_align_bitmap *map;
  26
  27         unsigned int wake_index;
  28         struct bt_wait_state *bs;
  29 };
  30
  31 /*
  32  * Tag address space map.
  33  */
  34 struct blk_mq_tags {
  35         unsigned int nr_tags;
  36         unsigned int nr_reserved_tags;
  37
  38         struct blk_mq_bitmap_tags bitmap_tags;
  39         struct blk_mq_bitmap_tags breserved_tags;
  40
  41         struct request **rqs;
  42         struct list_head page_list;
  43 };
  44
  45
  46 extern struct blk_mq_tags *blk_mq_init_tags(unsigned int nr_tags, unsigned int reserved_tags, int node);
  47 extern void blk_mq_free_tags(struct blk_mq_tags *tags);
  48
  49 extern unsigned int blk_mq_get_tag(struct blk_mq_tags *tags, struct blk_mq_hw_ctx *hctx, unsigned int *last_tag, gfp_t gfp, bool reserved);
  50 extern void blk_mq_wait_for_tags(struct blk_mq_tags *tags, struct blk_mq_hw_ctx *hctx, bool reserved);
  51 extern void blk_mq_put_tag(struct blk_mq_tags *tags, unsigned int tag, unsigned int *last_tag);
  52 extern void blk_mq_tag_busy_iter(struct blk_mq_tags *tags, void (*fn)(void *data, unsigned long *), void *data);
  53 extern bool blk_mq_has_free_tags(struct blk_mq_tags *tags);
  54 extern ssize_t blk_mq_tag_sysfs_show(struct blk_mq_tags *tags, char *page);
  55 extern void blk_mq_tag_init_last_tag(struct blk_mq_tags *tags, unsigned int *last_tag);
  56
  57 enum {
  58         BLK_MQ_TAG_CACHE_MIN    = 1,
  59         BLK_MQ_TAG_CACHE_MAX    = 64,
  60 };
  61
  62 enum {
  63         BLK_MQ_TAG_FAIL         = -1U,
  64         BLK_MQ_TAG_MIN          = BLK_MQ_TAG_CACHE_MIN,
  65         BLK_MQ_TAG_MAX          = BLK_MQ_TAG_FAIL - 1,
  66 };
  67
  68 #endif