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 /**
  11  * struct blk_mq_ctx - State for a software queue facing the submitting CPUs
  12  */
  13 struct blk_mq_ctx {
  14         struct {
  15                 spinlock_t              lock;
  16                 struct list_head        rq_list;
  17         }  ____cacheline_aligned_in_smp;
  18
  19         unsigned int            cpu;
  20         unsigned int            index_hw;
  21
  22         /* incremented at dispatch time */
  23         unsigned long           rq_dispatched[2];
  24         unsigned long           rq_merged;
  25
  26         /* incremented at completion time */
  27         unsigned long           ____cacheline_aligned_in_smp rq_completed[2];
  28
  29         struct request_queue    *queue;
  30         struct kobject          kobj;
  31 } ____cacheline_aligned_in_smp;
  32
  33 void blk_mq_freeze_queue(struct request_queue *q);
  34 void blk_mq_free_queue(struct request_queue *q);
  35 int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr);
  36 void blk_mq_wake_waiters(struct request_queue *q);
  37 bool blk_mq_dispatch_rq_list(struct request_queue *, struct list_head *, bool);
  38 void blk_mq_flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, struct list_head *list);
  39 bool blk_mq_get_driver_tag(struct request *rq, struct blk_mq_hw_ctx **hctx,
  40                                 bool wait);
  41 struct request *blk_mq_dequeue_from_ctx(struct blk_mq_hw_ctx *hctx,
  42                                         struct blk_mq_ctx *start);
  43
  44 /*
  45  * Internal helpers for allocating/freeing the request map
  46  */
  47 void blk_mq_free_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
  48                      unsigned int hctx_idx);
  49 void blk_mq_free_rq_map(struct blk_mq_tags *tags);
  50 struct blk_mq_tags *blk_mq_alloc_rq_map(struct blk_mq_tag_set *set,
  51                                         unsigned int hctx_idx,
  52                                         unsigned int nr_tags,
  53                                         unsigned int reserved_tags);
  54 int blk_mq_alloc_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
  55                      unsigned int hctx_idx, unsigned int depth);
  56
  57 /*
  58  * Internal helpers for request insertion into sw queues
  59  */
  60 void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq,
  61                                 bool at_head);
  62 void blk_mq_request_bypass_insert(struct request *rq, bool run_queue);
  63 void blk_mq_insert_requests(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx,
  64                                 struct list_head *list);
  65
  66 /* Used by blk_insert_cloned_request() to issue request directly */
  67 blk_status_t blk_mq_request_issue_directly(struct request *rq);
  68
  69 /*
  70  * CPU -> queue mappings
  71  */
  72 extern int blk_mq_hw_queue_to_node(unsigned int *map, unsigned int);
  73
  74 static inline struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q,
  75                 int cpu)
  76 {
  77         return q->queue_hw_ctx[q->mq_map[cpu]];
  78 }
  79
  80 /*
  81  * sysfs helpers
  82  */
  83 extern void blk_mq_sysfs_init(struct request_queue *q);
  84 extern void blk_mq_sysfs_deinit(struct request_queue *q);
  85 extern int __blk_mq_register_dev(struct device *dev, struct request_queue *q);
  86 extern int blk_mq_sysfs_register(struct request_queue *q);
  87 extern void blk_mq_sysfs_unregister(struct request_queue *q);
  88 extern void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx);
  89
  90 void blk_mq_release(struct request_queue *q);
  91
  92 /**
  93  * blk_mq_rq_state() - read the current MQ_RQ_* state of a request
  94  * @rq: target request.
  95  */
  96 static inline enum mq_rq_state blk_mq_rq_state(struct request *rq)
  97 {
  98         return READ_ONCE(rq->state);
  99 }
 100
 101 static inline struct blk_mq_ctx *__blk_mq_get_ctx(struct request_queue *q,
 102                                            unsigned int cpu)
 103 {
 104         return per_cpu_ptr(q->queue_ctx, cpu);
 105 }
 106
 107 /*
 108  * This assumes per-cpu software queueing queues. They could be per-node
 109  * as well, for instance. For now this is hardcoded as-is. Note that we don't
 110  * care about preemption, since we know the ctx's are persistent. This does
 111  * mean that we can't rely on ctx always matching the currently running CPU.
 112  */
 113 static inline struct blk_mq_ctx *blk_mq_get_ctx(struct request_queue *q)
 114 {
 115         return __blk_mq_get_ctx(q, get_cpu());
 116 }
 117
 118 static inline void blk_mq_put_ctx(struct blk_mq_ctx *ctx)
 119 {
 120         put_cpu();
 121 }
 122
 123 struct blk_mq_alloc_data {
 124         /* input parameter */
 125         struct request_queue *q;
 126         blk_mq_req_flags_t flags;
 127         unsigned int shallow_depth;
 128
 129         /* input & output parameter */
 130         struct blk_mq_ctx *ctx;
 131         struct blk_mq_hw_ctx *hctx;
 132 };
 133
 134 static inline struct blk_mq_tags *blk_mq_tags_from_data(struct blk_mq_alloc_data *data)
 135 {
 136         if (data->flags & BLK_MQ_REQ_INTERNAL)
 137                 return data->hctx->sched_tags;
 138
 139         return data->hctx->tags;
 140 }
 141
 142 static inline bool blk_mq_hctx_stopped(struct blk_mq_hw_ctx *hctx)
 143 {
 144         return test_bit(BLK_MQ_S_STOPPED, &hctx->state);
 145 }
 146
 147 static inline bool blk_mq_hw_queue_mapped(struct blk_mq_hw_ctx *hctx)
 148 {
 149         return hctx->nr_ctx && hctx->tags;
 150 }
 151
 152 void blk_mq_in_flight(struct request_queue *q, struct hd_struct *part,
 153                       unsigned int inflight[2]);
 154 void blk_mq_in_flight_rw(struct request_queue *q, struct hd_struct *part,
 155                          unsigned int inflight[2]);
 156
 157 static inline void blk_mq_put_dispatch_budget(struct blk_mq_hw_ctx *hctx)
 158 {
 159         struct request_queue *q = hctx->queue;
 160
 161         if (q->mq_ops->put_budget)
 162                 q->mq_ops->put_budget(hctx);
 163 }
 164
 165 static inline bool blk_mq_get_dispatch_budget(struct blk_mq_hw_ctx *hctx)
 166 {
 167         struct request_queue *q = hctx->queue;
 168
 169         if (q->mq_ops->get_budget)
 170                 return q->mq_ops->get_budget(hctx);
 171         return true;
 172 }
 173
 174 static inline void __blk_mq_put_driver_tag(struct blk_mq_hw_ctx *hctx,
 175                                            struct request *rq)
 176 {
 177         blk_mq_put_tag(hctx, hctx->tags, rq->mq_ctx, rq->tag);
 178         rq->tag = -1;
 179
 180         if (rq->rq_flags & RQF_MQ_INFLIGHT) {
 181                 rq->rq_flags &= ~RQF_MQ_INFLIGHT;
 182                 atomic_dec(&hctx->nr_active);
 183         }
 184 }
 185
 186 static inline void blk_mq_put_driver_tag_hctx(struct blk_mq_hw_ctx *hctx,
 187                                        struct request *rq)
 188 {
 189         if (rq->tag == -1 || rq->internal_tag == -1)
 190                 return;
 191
 192         __blk_mq_put_driver_tag(hctx, rq);
 193 }
 194
 195 static inline void blk_mq_put_driver_tag(struct request *rq)
 196 {
 197         struct blk_mq_hw_ctx *hctx;
 198
 199         if (rq->tag == -1 || rq->internal_tag == -1)
 200                 return;
 201
 202         hctx = blk_mq_map_queue(rq->q, rq->mq_ctx->cpu);
 203         __blk_mq_put_driver_tag(hctx, rq);
 204 }
 205
 206 #endif