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 #include "blk-mq-tag.h"
   7
   8 struct blk_mq_tag_set;
   9
  10 struct blk_mq_ctx {
  11         struct {
  12                 spinlock_t              lock;
  13                 struct list_head        rq_list;
  14         }  ____cacheline_aligned_in_smp;
  15
  16         unsigned int            cpu;
  17         unsigned int            index_hw;
  18
  19         /* incremented at dispatch time */
  20         unsigned long           rq_dispatched[2];
  21         unsigned long           rq_merged;
  22
  23         /* incremented at completion time */
  24         unsigned long           ____cacheline_aligned_in_smp rq_completed[2];
  25
  26         struct request_queue    *queue;
  27         struct kobject          kobj;
  28 } ____cacheline_aligned_in_smp;
  29
  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 *, bool);
  35 void blk_mq_flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, struct list_head *list);
  36 bool blk_mq_get_driver_tag(struct request *rq, struct blk_mq_hw_ctx **hctx,
  37                                 bool wait);
  38 struct request *blk_mq_dequeue_from_ctx(struct blk_mq_hw_ctx *hctx,
  39                                         struct blk_mq_ctx *start);
  40
  41 /*
  42  * Internal helpers for allocating/freeing the request map
  43  */
  44 void blk_mq_free_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
  45                      unsigned int hctx_idx);
  46 void blk_mq_free_rq_map(struct blk_mq_tags *tags);
  47 struct blk_mq_tags *blk_mq_alloc_rq_map(struct blk_mq_tag_set *set,
  48                                         unsigned int hctx_idx,
  49                                         unsigned int nr_tags,
  50                                         unsigned int reserved_tags);
  51 int blk_mq_alloc_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
  52                      unsigned int hctx_idx, unsigned int depth);
  53
  54 /*
  55  * Internal helpers for request insertion into sw queues
  56  */
  57 void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq,
  58                                 bool at_head);
  59 void blk_mq_request_bypass_insert(struct request *rq, bool run_queue);
  60 void blk_mq_insert_requests(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx,
  61                                 struct list_head *list);
  62
  63 /*
  64  * CPU -> queue mappings
  65  */
  66 extern int blk_mq_hw_queue_to_node(unsigned int *map, unsigned int);
  67
  68 static inline struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q,
  69                 int cpu)
  70 {
  71         return q->queue_hw_ctx[q->mq_map[cpu]];
  72 }
  73
  74 /*
  75  * sysfs helpers
  76  */
  77 extern void blk_mq_sysfs_init(struct request_queue *q);
  78 extern void blk_mq_sysfs_deinit(struct request_queue *q);
  79 extern int __blk_mq_register_dev(struct device *dev, struct request_queue *q);
  80 extern int blk_mq_sysfs_register(struct request_queue *q);
  81 extern void blk_mq_sysfs_unregister(struct request_queue *q);
  82 extern void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx);
  83
  84 extern void blk_mq_rq_timed_out(struct request *req, bool reserved);
  85
  86 void blk_mq_release(struct request_queue *q);
  87
  88 static inline struct blk_mq_ctx *__blk_mq_get_ctx(struct request_queue *q,
  89                                            unsigned int cpu)
  90 {
  91         return per_cpu_ptr(q->queue_ctx, cpu);
  92 }
  93
  94 /*
  95  * This assumes per-cpu software queueing queues. They could be per-node
  96  * as well, for instance. For now this is hardcoded as-is. Note that we don't
  97  * care about preemption, since we know the ctx's are persistent. This does
  98  * mean that we can't rely on ctx always matching the currently running CPU.
  99  */
 100 static inline struct blk_mq_ctx *blk_mq_get_ctx(struct request_queue *q)
 101 {
 102         return __blk_mq_get_ctx(q, get_cpu());
 103 }
 104
 105 static inline void blk_mq_put_ctx(struct blk_mq_ctx *ctx)
 106 {
 107         put_cpu();
 108 }
 109
 110 struct blk_mq_alloc_data {
 111         /* input parameter */
 112         struct request_queue *q;
 113         blk_mq_req_flags_t flags;
 114         unsigned int shallow_depth;
 115
 116         /* input & output parameter */
 117         struct blk_mq_ctx *ctx;
 118         struct blk_mq_hw_ctx *hctx;
 119 };
 120
 121 static inline struct blk_mq_tags *blk_mq_tags_from_data(struct blk_mq_alloc_data *data)
 122 {
 123         if (data->flags & BLK_MQ_REQ_INTERNAL)
 124                 return data->hctx->sched_tags;
 125
 126         return data->hctx->tags;
 127 }
 128
 129 static inline bool blk_mq_hctx_stopped(struct blk_mq_hw_ctx *hctx)
 130 {
 131         return test_bit(BLK_MQ_S_STOPPED, &hctx->state);
 132 }
 133
 134 static inline bool blk_mq_hw_queue_mapped(struct blk_mq_hw_ctx *hctx)
 135 {
 136         return hctx->nr_ctx && hctx->tags;
 137 }
 138
 139 void blk_mq_in_flight(struct request_queue *q, struct hd_struct *part,
 140                         unsigned int inflight[2]);
 141
 142 static inline void blk_mq_put_dispatch_budget(struct blk_mq_hw_ctx *hctx)
 143 {
 144         struct request_queue *q = hctx->queue;
 145
 146         if (q->mq_ops->put_budget)
 147                 q->mq_ops->put_budget(hctx);
 148 }
 149
 150 static inline bool blk_mq_get_dispatch_budget(struct blk_mq_hw_ctx *hctx)
 151 {
 152         struct request_queue *q = hctx->queue;
 153
 154         if (q->mq_ops->get_budget)
 155                 return q->mq_ops->get_budget(hctx);
 156         return true;
 157 }
 158
 159 static inline void __blk_mq_put_driver_tag(struct blk_mq_hw_ctx *hctx,
 160                                            struct request *rq)
 161 {
 162         blk_mq_put_tag(hctx, hctx->tags, rq->mq_ctx, rq->tag);
 163         rq->tag = -1;
 164
 165         if (rq->rq_flags & RQF_MQ_INFLIGHT) {
 166                 rq->rq_flags &= ~RQF_MQ_INFLIGHT;
 167                 atomic_dec(&hctx->nr_active);
 168         }
 169 }
 170
 171 static inline void blk_mq_put_driver_tag_hctx(struct blk_mq_hw_ctx *hctx,
 172                                        struct request *rq)
 173 {
 174         if (rq->tag == -1 || rq->internal_tag == -1)
 175                 return;
 176
 177         __blk_mq_put_driver_tag(hctx, rq);
 178 }
 179
 180 static inline void blk_mq_put_driver_tag(struct request *rq)
 181 {
 182         struct blk_mq_hw_ctx *hctx;
 183
 184         if (rq->tag == -1 || rq->internal_tag == -1)
 185                 return;
 186
 187         hctx = blk_mq_map_queue(rq->q, rq->mq_ctx->cpu);
 188         __blk_mq_put_driver_tag(hctx, rq);
 189 }
 190
 191 #endif