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         atomic_t 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         atomic_t active_queues;
  39
  40         struct blk_mq_bitmap_tags bitmap_tags;
  41         struct blk_mq_bitmap_tags breserved_tags;
  42
  43         struct request **rqs;
  44         struct list_head page_list;
  45 };
  46
  47
  48 extern struct blk_mq_tags *blk_mq_init_tags(unsigned int nr_tags, unsigned int reserved_tags, int node);
  49 extern void blk_mq_free_tags(struct blk_mq_tags *tags);
  50
  51 extern unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data);
  52 extern void blk_mq_put_tag(struct blk_mq_hw_ctx *hctx, unsigned int tag, unsigned int *last_tag);
  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 extern int blk_mq_tag_update_depth(struct blk_mq_tags *tags, unsigned int depth);
  57
  58 enum {
  59         BLK_MQ_TAG_CACHE_MIN    = 1,
  60         BLK_MQ_TAG_CACHE_MAX    = 64,
  61 };
  62
  63 enum {
  64         BLK_MQ_TAG_FAIL         = -1U,
  65         BLK_MQ_TAG_MIN          = BLK_MQ_TAG_CACHE_MIN,
  66         BLK_MQ_TAG_MAX          = BLK_MQ_TAG_FAIL - 1,
  67 };
  68
  69 extern bool __blk_mq_tag_busy(struct blk_mq_hw_ctx *);
  70 extern void __blk_mq_tag_idle(struct blk_mq_hw_ctx *);
  71
  72 static inline bool blk_mq_tag_busy(struct blk_mq_hw_ctx *hctx)
  73 {
  74         if (!(hctx->flags & BLK_MQ_F_TAG_SHARED))
  75                 return false;
  76
  77         return __blk_mq_tag_busy(hctx);
  78 }
  79
  80 static inline void blk_mq_tag_idle(struct blk_mq_hw_ctx *hctx)
  81 {
  82         if (!(hctx->flags & BLK_MQ_F_TAG_SHARED))
  83                 return;
  84
  85         __blk_mq_tag_idle(hctx);
  86 }
  87
  88 /*
  89  * This helper should only be used for flush request to share tag
  90  * with the request cloned from, and both the two requests can't be
  91  * in flight at the same time. The caller has to make sure the tag
  92  * can't be freed.
  93  */
  94 static inline void blk_mq_tag_set_rq(struct blk_mq_hw_ctx *hctx,
  95                 unsigned int tag, struct request *rq)
  96 {
  97         hctx->tags->rqs[tag] = rq;
  98 }
  99
 100 #endif