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);
  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(unsigned int *map, unsigned int);
  74
  75 static inline struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q,
  76                 int cpu)
  77 {
  78         return q->queue_hw_ctx[q->mq_map[cpu]];
  79 }
  80
  81 /*
  82  * sysfs helpers
  83  */
  84 extern void blk_mq_sysfs_init(struct request_queue *q);
  85 extern void blk_mq_sysfs_deinit(struct request_queue *q);
  86 extern int __blk_mq_register_dev(struct device *dev, struct request_queue *q);
  87 extern int blk_mq_sysfs_register(struct request_queue *q);
  88 extern void blk_mq_sysfs_unregister(struct request_queue *q);
  89 extern void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx);
  90
  91 void blk_mq_release(struct request_queue *q);
  92
  93 /**
  94  * blk_mq_rq_state() - read the current MQ_RQ_* state of a request
  95  * @rq: target request.
  96  */
  97 static inline enum mq_rq_state blk_mq_rq_state(struct request *rq)
  98 {
  99         return READ_ONCE(rq->state);
 100 }
 101
 102 static inline struct blk_mq_ctx *__blk_mq_get_ctx(struct request_queue *q,
 103                                            unsigned int cpu)
 104 {
 105         return per_cpu_ptr(q->queue_ctx, cpu);
 106 }
 107
 108 /*
 109  * This assumes per-cpu software queueing queues. They could be per-node
 110  * as well, for instance. For now this is hardcoded as-is. Note that we don't
 111  * care about preemption, since we know the ctx's are persistent. This does
 112  * mean that we can't rely on ctx always matching the currently running CPU.
 113  */
 114 static inline struct blk_mq_ctx *blk_mq_get_ctx(struct request_queue *q)
 115 {
 116         return __blk_mq_get_ctx(q, get_cpu());
 117 }
 118
 119 static inline void blk_mq_put_ctx(struct blk_mq_ctx *ctx)
 120 {
 121         put_cpu();
 122 }
 123
 124 struct blk_mq_alloc_data {
 125         /* input parameter */
 126         struct request_queue *q;
 127         blk_mq_req_flags_t flags;
 128         unsigned int shallow_depth;
 129
 130         /* input & output parameter */
 131         struct blk_mq_ctx *ctx;
 132         struct blk_mq_hw_ctx *hctx;
 133 };
 134
 135 static inline struct blk_mq_tags *blk_mq_tags_from_data(struct blk_mq_alloc_data *data)
 136 {
 137         if (data->flags & BLK_MQ_REQ_INTERNAL)
 138                 return data->hctx->sched_tags;
 139
 140         return data->hctx->tags;
 141 }
 142
 143 static inline bool blk_mq_hctx_stopped(struct blk_mq_hw_ctx *hctx)
 144 {
 145         return test_bit(BLK_MQ_S_STOPPED, &hctx->state);
 146 }
 147
 148 static inline bool blk_mq_hw_queue_mapped(struct blk_mq_hw_ctx *hctx)
 149 {
 150         return hctx->nr_ctx && hctx->tags;
 151 }
 152
 153 void blk_mq_in_flight(struct request_queue *q, struct hd_struct *part,
 154                       unsigned int inflight[2]);
 155 void blk_mq_in_flight_rw(struct request_queue *q, struct hd_struct *part,
 156                          unsigned int inflight[2]);
 157
 158 static inline void blk_mq_put_dispatch_budget(struct blk_mq_hw_ctx *hctx)
 159 {
 160         struct request_queue *q = hctx->queue;
 161
 162         if (q->mq_ops->put_budget)
 163                 q->mq_ops->put_budget(hctx);
 164 }
 165
 166 static inline bool blk_mq_get_dispatch_budget(struct blk_mq_hw_ctx *hctx)
 167 {
 168         struct request_queue *q = hctx->queue;
 169
 170         if (q->mq_ops->get_budget)
 171                 return q->mq_ops->get_budget(hctx);
 172         return true;
 173 }
 174
 175 static inline void __blk_mq_put_driver_tag(struct blk_mq_hw_ctx *hctx,
 176                                            struct request *rq)
 177 {
 178         blk_mq_put_tag(hctx, hctx->tags, rq->mq_ctx, rq->tag);
 179         rq->tag = -1;
 180
 181         if (rq->rq_flags & RQF_MQ_INFLIGHT) {
 182                 rq->rq_flags &= ~RQF_MQ_INFLIGHT;
 183                 atomic_dec(&hctx->nr_active);
 184         }
 185 }
 186
 187 static inline void blk_mq_put_driver_tag_hctx(struct blk_mq_hw_ctx *hctx,
 188                                        struct request *rq)
 189 {
 190         if (rq->tag == -1 || rq->internal_tag == -1)
 191                 return;
 192
 193         __blk_mq_put_driver_tag(hctx, rq);
 194 }
 195
 196 static inline void blk_mq_put_driver_tag(struct request *rq)
 197 {
 198         struct blk_mq_hw_ctx *hctx;
 199
 200         if (rq->tag == -1 || rq->internal_tag == -1)
 201                 return;
 202
 203         hctx = blk_mq_map_queue(rq->q, rq->mq_ctx->cpu);
 204         __blk_mq_put_driver_tag(hctx, rq);
 205 }
 206
 207 static inline void blk_mq_clear_mq_map(struct blk_mq_tag_set *set)
 208 {
 209         int cpu;
 210
 211         for_each_possible_cpu(cpu)
 212                 set->mq_map[cpu] = 0;
 213 }
 214
 215 #endif