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 short          index_hw[HCTX_MAX_TYPES];
  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);
  40 struct request *blk_mq_dequeue_from_ctx(struct blk_mq_hw_ctx *hctx,
  41                                         struct blk_mq_ctx *start);
  42
  43 /*
  44  * Internal helpers for allocating/freeing the request map
  45  */
  46 void blk_mq_free_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
  47                      unsigned int hctx_idx);
  48 void blk_mq_free_rq_map(struct blk_mq_tags *tags);
  49 struct blk_mq_tags *blk_mq_alloc_rq_map(struct blk_mq_tag_set *set,
  50                                         unsigned int hctx_idx,
  51                                         unsigned int nr_tags,
  52                                         unsigned int reserved_tags);
  53 int blk_mq_alloc_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
  54                      unsigned int hctx_idx, unsigned int depth);
  55
  56 /*
  57  * Internal helpers for request insertion into sw queues
  58  */
  59 void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq,
  60                                 bool at_head);
  61 void blk_mq_request_bypass_insert(struct request *rq, bool run_queue);
  62 void blk_mq_insert_requests(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx,
  63                                 struct list_head *list);
  64
  65 /* Used by blk_insert_cloned_request() to issue request directly */
  66 blk_status_t blk_mq_request_issue_directly(struct request *rq);
  67 void blk_mq_try_issue_list_directly(struct blk_mq_hw_ctx *hctx,
  68                                     struct list_head *list);
  69
  70 /*
  71  * CPU -> queue mappings
  72  */
  73 extern int blk_mq_hw_queue_to_node(struct blk_mq_queue_map *qmap, unsigned int);
  74
  75 /*
  76  * blk_mq_map_queue_type() - map (hctx_type,cpu) to hardware queue
  77  * @q: request queue
  78  * @hctx_type: the hctx type index
  79  * @cpu: CPU
  80  */
  81 static inline struct blk_mq_hw_ctx *blk_mq_map_queue_type(struct request_queue *q,
  82                                                           unsigned int hctx_type,
  83                                                           unsigned int cpu)
  84 {
  85         struct blk_mq_tag_set *set = q->tag_set;
  86
  87         return q->queue_hw_ctx[set->map[hctx_type].mq_map[cpu]];
  88 }
  89
  90 /*
  91  * blk_mq_map_queue() - map (cmd_flags,type) to hardware queue
  92  * @q: request queue
  93  * @flags: request command flags
  94  * @cpu: CPU
  95  */
  96 static inline struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q,
  97                                                      unsigned int flags,
  98                                                      unsigned int cpu)
  99 {
 100         int hctx_type = 0;
 101
 102         if (q->mq_ops->rq_flags_to_type)
 103                 hctx_type = q->mq_ops->rq_flags_to_type(q, flags);
 104
 105         return blk_mq_map_queue_type(q, hctx_type, cpu);
 106 }
 107
 108 /*
 109  * sysfs helpers
 110  */
 111 extern void blk_mq_sysfs_init(struct request_queue *q);
 112 extern void blk_mq_sysfs_deinit(struct request_queue *q);
 113 extern int __blk_mq_register_dev(struct device *dev, struct request_queue *q);
 114 extern int blk_mq_sysfs_register(struct request_queue *q);
 115 extern void blk_mq_sysfs_unregister(struct request_queue *q);
 116 extern void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx);
 117
 118 void blk_mq_release(struct request_queue *q);
 119
 120 /**
 121  * blk_mq_rq_state() - read the current MQ_RQ_* state of a request
 122  * @rq: target request.
 123  */
 124 static inline enum mq_rq_state blk_mq_rq_state(struct request *rq)
 125 {
 126         return READ_ONCE(rq->state);
 127 }
 128
 129 static inline struct blk_mq_ctx *__blk_mq_get_ctx(struct request_queue *q,
 130                                            unsigned int cpu)
 131 {
 132         return per_cpu_ptr(q->queue_ctx, cpu);
 133 }
 134
 135 /*
 136  * This assumes per-cpu software queueing queues. They could be per-node
 137  * as well, for instance. For now this is hardcoded as-is. Note that we don't
 138  * care about preemption, since we know the ctx's are persistent. This does
 139  * mean that we can't rely on ctx always matching the currently running CPU.
 140  */
 141 static inline struct blk_mq_ctx *blk_mq_get_ctx(struct request_queue *q)
 142 {
 143         return __blk_mq_get_ctx(q, get_cpu());
 144 }
 145
 146 static inline void blk_mq_put_ctx(struct blk_mq_ctx *ctx)
 147 {
 148         put_cpu();
 149 }
 150
 151 struct blk_mq_alloc_data {
 152         /* input parameter */
 153         struct request_queue *q;
 154         blk_mq_req_flags_t flags;
 155         unsigned int shallow_depth;
 156         unsigned int cmd_flags;
 157
 158         /* input & output parameter */
 159         struct blk_mq_ctx *ctx;
 160         struct blk_mq_hw_ctx *hctx;
 161 };
 162
 163 static inline struct blk_mq_tags *blk_mq_tags_from_data(struct blk_mq_alloc_data *data)
 164 {
 165         if (data->flags & BLK_MQ_REQ_INTERNAL)
 166                 return data->hctx->sched_tags;
 167
 168         return data->hctx->tags;
 169 }
 170
 171 static inline bool blk_mq_hctx_stopped(struct blk_mq_hw_ctx *hctx)
 172 {
 173         return test_bit(BLK_MQ_S_STOPPED, &hctx->state);
 174 }
 175
 176 static inline bool blk_mq_hw_queue_mapped(struct blk_mq_hw_ctx *hctx)
 177 {
 178         return hctx->nr_ctx && hctx->tags;
 179 }
 180
 181 void blk_mq_in_flight(struct request_queue *q, struct hd_struct *part,
 182                       unsigned int inflight[2]);
 183 void blk_mq_in_flight_rw(struct request_queue *q, struct hd_struct *part,
 184                          unsigned int inflight[2]);
 185
 186 static inline void blk_mq_put_dispatch_budget(struct blk_mq_hw_ctx *hctx)
 187 {
 188         struct request_queue *q = hctx->queue;
 189
 190         if (q->mq_ops->put_budget)
 191                 q->mq_ops->put_budget(hctx);
 192 }
 193
 194 static inline bool blk_mq_get_dispatch_budget(struct blk_mq_hw_ctx *hctx)
 195 {
 196         struct request_queue *q = hctx->queue;
 197
 198         if (q->mq_ops->get_budget)
 199                 return q->mq_ops->get_budget(hctx);
 200         return true;
 201 }
 202
 203 static inline void __blk_mq_put_driver_tag(struct blk_mq_hw_ctx *hctx,
 204                                            struct request *rq)
 205 {
 206         blk_mq_put_tag(hctx, hctx->tags, rq->mq_ctx, rq->tag);
 207         rq->tag = -1;
 208
 209         if (rq->rq_flags & RQF_MQ_INFLIGHT) {
 210                 rq->rq_flags &= ~RQF_MQ_INFLIGHT;
 211                 atomic_dec(&hctx->nr_active);
 212         }
 213 }
 214
 215 static inline void blk_mq_put_driver_tag_hctx(struct blk_mq_hw_ctx *hctx,
 216                                        struct request *rq)
 217 {
 218         if (rq->tag == -1 || rq->internal_tag == -1)
 219                 return;
 220
 221         __blk_mq_put_driver_tag(hctx, rq);
 222 }
 223
 224 static inline void blk_mq_put_driver_tag(struct request *rq)
 225 {
 226         if (rq->tag == -1 || rq->internal_tag == -1)
 227                 return;
 228
 229         __blk_mq_put_driver_tag(rq->mq_hctx, rq);
 230 }
 231
 232 static inline void blk_mq_clear_mq_map(struct blk_mq_queue_map *qmap)
 233 {
 234         int cpu;
 235
 236         for_each_possible_cpu(cpu)
 237                 qmap->mq_map[cpu] = 0;
 238 }
 239
 240 #endif