block/blk-mq.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef INT_BLK_MQ_H
   3 #define INT_BLK_MQ_H
   4
   5 #include "blk-stat.h"
   6
   7 struct blk_mq_tag_set;
   8
   9 struct blk_mq_ctx {
  10         struct {
  11                 spinlock_t              lock;
  12                 struct list_head        rq_list;
  13         }  ____cacheline_aligned_in_smp;
  14
  15         unsigned int            cpu;
  16         unsigned int            index_hw;
  17
  18         /* incremented at dispatch time */
  19         unsigned long           rq_dispatched[2];
  20         unsigned long           rq_merged;
  21
  22         /* incremented at completion time */
  23         unsigned long           ____cacheline_aligned_in_smp rq_completed[2];
  24
  25         struct request_queue    *queue;
  26         struct kobject          kobj;
  27 } ____cacheline_aligned_in_smp;
  28
  29 void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async);
  30 void blk_mq_freeze_queue(struct request_queue *q);
  31 void blk_mq_free_queue(struct request_queue *q);
  32 int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr);
  33 void blk_mq_wake_waiters(struct request_queue *q);
  34 bool blk_mq_dispatch_rq_list(struct request_queue *, struct list_head *);
  35 void blk_mq_flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, struct list_head *list);
  36 bool blk_mq_hctx_has_pending(struct blk_mq_hw_ctx *hctx);
  37 bool blk_mq_get_driver_tag(struct request *rq, struct blk_mq_hw_ctx **hctx,
  38                                 bool wait);
  39
  40 /*
  41  * Internal helpers for allocating/freeing the request map
  42  */
  43 void blk_mq_free_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
  44                      unsigned int hctx_idx);
  45 void blk_mq_free_rq_map(struct blk_mq_tags *tags);
  46 struct blk_mq_tags *blk_mq_alloc_rq_map(struct blk_mq_tag_set *set,
  47                                         unsigned int hctx_idx,
  48                                         unsigned int nr_tags,
  49                                         unsigned int reserved_tags);
  50 int blk_mq_alloc_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
  51                      unsigned int hctx_idx, unsigned int depth);
  52
  53 /*
  54  * Internal helpers for request insertion into sw queues
  55  */
  56 void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq,
  57                                 bool at_head);
  58 void blk_mq_request_bypass_insert(struct request *rq);
  59 void blk_mq_insert_requests(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx,
  60                                 struct list_head *list);
  61
  62 /*
  63  * CPU -> queue mappings
  64  */
  65 extern int blk_mq_hw_queue_to_node(unsigned int *map, unsigned int);
  66
  67 static inline struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q,
  68                 int cpu)
  69 {
  70         return q->queue_hw_ctx[q->mq_map[cpu]];
  71 }
  72
  73 /*
  74  * sysfs helpers
  75  */
  76 extern void blk_mq_sysfs_init(struct request_queue *q);
  77 extern void blk_mq_sysfs_deinit(struct request_queue *q);
  78 extern int __blk_mq_register_dev(struct device *dev, struct request_queue *q);
  79 extern int blk_mq_sysfs_register(struct request_queue *q);
  80 extern void blk_mq_sysfs_unregister(struct request_queue *q);
  81 extern void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx);
  82
  83 extern void blk_mq_rq_timed_out(struct request *req, bool reserved);
  84
  85 void blk_mq_release(struct request_queue *q);
  86
  87 static inline struct blk_mq_ctx *__blk_mq_get_ctx(struct request_queue *q,
  88                                            unsigned int cpu)
  89 {
  90         return per_cpu_ptr(q->queue_ctx, cpu);
  91 }
  92
  93 /*
  94  * This assumes per-cpu software queueing queues. They could be per-node
  95  * as well, for instance. For now this is hardcoded as-is. Note that we don't
  96  * care about preemption, since we know the ctx's are persistent. This does
  97  * mean that we can't rely on ctx always matching the currently running CPU.
  98  */
  99 static inline struct blk_mq_ctx *blk_mq_get_ctx(struct request_queue *q)
 100 {
 101         return __blk_mq_get_ctx(q, get_cpu());
 102 }
 103
 104 static inline void blk_mq_put_ctx(struct blk_mq_ctx *ctx)
 105 {
 106         put_cpu();
 107 }
 108
 109 struct blk_mq_alloc_data {
 110         /* input parameter */
 111         struct request_queue *q;
 112         unsigned int flags;
 113         unsigned int shallow_depth;
 114
 115         /* input & output parameter */
 116         struct blk_mq_ctx *ctx;
 117         struct blk_mq_hw_ctx *hctx;
 118 };
 119
 120 static inline struct blk_mq_tags *blk_mq_tags_from_data(struct blk_mq_alloc_data *data)
 121 {
 122         if (data->flags & BLK_MQ_REQ_INTERNAL)
 123                 return data->hctx->sched_tags;
 124
 125         return data->hctx->tags;
 126 }
 127
 128 static inline bool blk_mq_hctx_stopped(struct blk_mq_hw_ctx *hctx)
 129 {
 130         return test_bit(BLK_MQ_S_STOPPED, &hctx->state);
 131 }
 132
 133 static inline bool blk_mq_hw_queue_mapped(struct blk_mq_hw_ctx *hctx)
 134 {
 135         return hctx->nr_ctx && hctx->tags;
 136 }
 137
 138 void blk_mq_in_flight(struct request_queue *q, struct hd_struct *part,
 139                         unsigned int inflight[2]);
 140
 141 #endif