block/blk-mq-tag.h

   1 #ifndef INT_BLK_MQ_TAG_H
   2 #define INT_BLK_MQ_TAG_H
   3
   4 #include <linux/percpu_ida.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         unsigned int nr_batch_move;
  13         unsigned int nr_max_cache;
  14
  15         struct percpu_ida free_tags;
  16         struct percpu_ida reserved_tags;
  17
  18         struct request **rqs;
  19         struct list_head page_list;
  20 };
  21
  22
  23 extern struct blk_mq_tags *blk_mq_init_tags(unsigned int nr_tags, unsigned int reserved_tags, int node);
  24 extern void blk_mq_free_tags(struct blk_mq_tags *tags);
  25
  26 extern unsigned int blk_mq_get_tag(struct blk_mq_tags *tags, gfp_t gfp, bool reserved);
  27 extern void blk_mq_wait_for_tags(struct blk_mq_tags *tags, bool reserved);
  28 extern void blk_mq_put_tag(struct blk_mq_tags *tags, unsigned int tag);
  29 extern void blk_mq_tag_busy_iter(struct blk_mq_tags *tags, void (*fn)(void *data, unsigned long *), void *data);
  30 extern bool blk_mq_has_free_tags(struct blk_mq_tags *tags);
  31 extern ssize_t blk_mq_tag_sysfs_show(struct blk_mq_tags *tags, char *page);
  32
  33 enum {
  34         BLK_MQ_TAG_CACHE_MIN    = 1,
  35         BLK_MQ_TAG_CACHE_MAX    = 64,
  36 };
  37
  38 enum {
  39         BLK_MQ_TAG_FAIL         = -1U,
  40         BLK_MQ_TAG_MIN          = BLK_MQ_TAG_CACHE_MIN,
  41         BLK_MQ_TAG_MAX          = BLK_MQ_TAG_FAIL - 1,
  42 };
  43
  44 #endif