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_ctxs {
  11         struct kobject kobj;
  12         struct blk_mq_ctx __percpu      *queue_ctx;
  13 };
  14
  15 /**
  16  * struct blk_mq_ctx - State for a software queue facing the submitting CPUs
  17  */
  18 struct blk_mq_ctx {
  19         struct {
  20                 spinlock_t              lock;
  21                 struct list_head        rq_lists[HCTX_MAX_TYPES];
  22         } ____cacheline_aligned_in_smp;
  23
  24         unsigned int            cpu;
  25         unsigned short          index_hw[HCTX_MAX_TYPES];
  26
  27         /* incremented at dispatch time */
  28         unsigned long           rq_dispatched[2];
  29         unsigned long           rq_merged;
  30
  31         /* incremented at completion time */
  32         unsigned long           ____cacheline_aligned_in_smp rq_completed[2];
  33
  34         struct request_queue    *queue;
  35         struct blk_mq_ctxs      *ctxs;
  36         struct kobject          kobj;
  37 } ____cacheline_aligned_in_smp;
  38
  39 void blk_mq_freeze_queue(struct request_queue *q);
  40 void blk_mq_free_queue(struct request_queue *q);
  41 int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr);
  42 void blk_mq_wake_waiters(struct request_queue *q);
  43 bool blk_mq_dispatch_rq_list(struct request_queue *, struct list_head *, bool);
  44 void blk_mq_flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, struct list_head *list);
  45 bool blk_mq_get_driver_tag(struct request *rq);
  46 struct request *blk_mq_dequeue_from_ctx(struct blk_mq_hw_ctx *hctx,
  47                                         struct blk_mq_ctx *start);
  48
  49 /*
  50  * Internal helpers for allocating/freeing the request map
  51  */
  52 void blk_mq_free_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
  53                      unsigned int hctx_idx);
  54 void blk_mq_free_rq_map(struct blk_mq_tags *tags);
  55 struct blk_mq_tags *blk_mq_alloc_rq_map(struct blk_mq_tag_set *set,
  56                                         unsigned int hctx_idx,
  57                                         unsigned int nr_tags,
  58                                         unsigned int reserved_tags);
  59 int blk_mq_alloc_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
  60                      unsigned int hctx_idx, unsigned int depth);
  61
  62 /*
  63  * Internal helpers for request insertion into sw queues
  64  */
  65 void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq,
  66                                 bool at_head);
  67 void blk_mq_request_bypass_insert(struct request *rq, bool run_queue);
  68 void blk_mq_insert_requests(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx,
  69                                 struct list_head *list);
  70
  71 blk_status_t blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx,
  72                                                 struct request *rq,
  73                                                 blk_qc_t *cookie,
  74                                                 bool bypass, bool last);
  75 void blk_mq_try_issue_list_directly(struct blk_mq_hw_ctx *hctx,
  76                                     struct list_head *list);
  77
  78 /*
  79  * CPU -> queue mappings
  80  */
  81 extern int blk_mq_hw_queue_to_node(struct blk_mq_queue_map *qmap, unsigned int);
  82
  83 /*
  84  * blk_mq_map_queue_type() - map (hctx_type,cpu) to hardware queue
  85  * @q: request queue
  86  * @type: the hctx type index
  87  * @cpu: CPU
  88  */
  89 static inline struct blk_mq_hw_ctx *blk_mq_map_queue_type(struct request_queue *q,
  90                                                           enum hctx_type type,
  91                                                           unsigned int cpu)
  92 {
  93         return q->queue_hw_ctx[q->tag_set->map[type].mq_map[cpu]];
  94 }
  95
  96 /*
  97  * blk_mq_map_queue() - map (cmd_flags,type) to hardware queue
  98  * @q: request queue
  99  * @flags: request command flags
 100  * @cpu: CPU
 101  */
 102 static inline struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q,
 103                                                      unsigned int flags,
 104                                                      unsigned int cpu)
 105 {
 106         enum hctx_type type = HCTX_TYPE_DEFAULT;
 107
 108         if ((flags & REQ_HIPRI) &&
 109             q->tag_set->nr_maps > HCTX_TYPE_POLL &&
 110             q->tag_set->map[HCTX_TYPE_POLL].nr_queues &&
 111             test_bit(QUEUE_FLAG_POLL, &q->queue_flags))
 112                 type = HCTX_TYPE_POLL;
 113
 114         else if (((flags & REQ_OP_MASK) == REQ_OP_READ) &&
 115                  q->tag_set->nr_maps > HCTX_TYPE_READ &&
 116                  q->tag_set->map[HCTX_TYPE_READ].nr_queues)
 117                 type = HCTX_TYPE_READ;
 118
 119         return blk_mq_map_queue_type(q, type, cpu);
 120 }
 121
 122 /*
 123  * sysfs helpers
 124  */
 125 extern void blk_mq_sysfs_init(struct request_queue *q);
 126 extern void blk_mq_sysfs_deinit(struct request_queue *q);
 127 extern int __blk_mq_register_dev(struct device *dev, struct request_queue *q);
 128 extern int blk_mq_sysfs_register(struct request_queue *q);
 129 extern void blk_mq_sysfs_unregister(struct request_queue *q);
 130 extern void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx);
 131
 132 void blk_mq_release(struct request_queue *q);
 133
 134 /**
 135  * blk_mq_rq_state() - read the current MQ_RQ_* state of a request
 136  * @rq: target request.
 137  */
 138 static inline enum mq_rq_state blk_mq_rq_state(struct request *rq)
 139 {
 140         return READ_ONCE(rq->state);
 141 }
 142
 143 static inline struct blk_mq_ctx *__blk_mq_get_ctx(struct request_queue *q,
 144                                            unsigned int cpu)
 145 {
 146         return per_cpu_ptr(q->queue_ctx, cpu);
 147 }
 148
 149 /*
 150  * This assumes per-cpu software queueing queues. They could be per-node
 151  * as well, for instance. For now this is hardcoded as-is. Note that we don't
 152  * care about preemption, since we know the ctx's are persistent. This does
 153  * mean that we can't rely on ctx always matching the currently running CPU.
 154  */
 155 static inline struct blk_mq_ctx *blk_mq_get_ctx(struct request_queue *q)
 156 {
 157         return __blk_mq_get_ctx(q, get_cpu());
 158 }
 159
 160 static inline void blk_mq_put_ctx(struct blk_mq_ctx *ctx)
 161 {
 162         put_cpu();
 163 }
 164
 165 struct blk_mq_alloc_data {
 166         /* input parameter */
 167         struct request_queue *q;
 168         blk_mq_req_flags_t flags;
 169         unsigned int shallow_depth;
 170         unsigned int cmd_flags;
 171
 172         /* input & output parameter */
 173         struct blk_mq_ctx *ctx;
 174         struct blk_mq_hw_ctx *hctx;
 175 };
 176
 177 static inline struct blk_mq_tags *blk_mq_tags_from_data(struct blk_mq_alloc_data *data)
 178 {
 179         if (data->flags & BLK_MQ_REQ_INTERNAL)
 180                 return data->hctx->sched_tags;
 181
 182         return data->hctx->tags;
 183 }
 184
 185 static inline bool blk_mq_hctx_stopped(struct blk_mq_hw_ctx *hctx)
 186 {
 187         return test_bit(BLK_MQ_S_STOPPED, &hctx->state);
 188 }
 189
 190 static inline bool blk_mq_hw_queue_mapped(struct blk_mq_hw_ctx *hctx)
 191 {
 192         return hctx->nr_ctx && hctx->tags;
 193 }
 194
 195 unsigned int blk_mq_in_flight(struct request_queue *q, struct hd_struct *part);
 196 void blk_mq_in_flight_rw(struct request_queue *q, struct hd_struct *part,
 197                          unsigned int inflight[2]);
 198
 199 static inline void blk_mq_put_dispatch_budget(struct blk_mq_hw_ctx *hctx)
 200 {
 201         struct request_queue *q = hctx->queue;
 202
 203         if (q->mq_ops->put_budget)
 204                 q->mq_ops->put_budget(hctx);
 205 }
 206
 207 static inline bool blk_mq_get_dispatch_budget(struct blk_mq_hw_ctx *hctx)
 208 {
 209         struct request_queue *q = hctx->queue;
 210
 211         if (q->mq_ops->get_budget)
 212                 return q->mq_ops->get_budget(hctx);
 213         return true;
 214 }
 215
 216 static inline void __blk_mq_put_driver_tag(struct blk_mq_hw_ctx *hctx,
 217                                            struct request *rq)
 218 {
 219         blk_mq_put_tag(hctx, hctx->tags, rq->mq_ctx, rq->tag);
 220         rq->tag = -1;
 221
 222         if (rq->rq_flags & RQF_MQ_INFLIGHT) {
 223                 rq->rq_flags &= ~RQF_MQ_INFLIGHT;
 224                 atomic_dec(&hctx->nr_active);
 225         }
 226 }
 227
 228 static inline void blk_mq_put_driver_tag_hctx(struct blk_mq_hw_ctx *hctx,
 229                                        struct request *rq)
 230 {
 231         if (rq->tag == -1 || rq->internal_tag == -1)
 232                 return;
 233
 234         __blk_mq_put_driver_tag(hctx, rq);
 235 }
 236
 237 static inline void blk_mq_put_driver_tag(struct request *rq)
 238 {
 239         if (rq->tag == -1 || rq->internal_tag == -1)
 240                 return;
 241
 242         __blk_mq_put_driver_tag(rq->mq_hctx, rq);
 243 }
 244
 245 static inline void blk_mq_clear_mq_map(struct blk_mq_queue_map *qmap)
 246 {
 247         int cpu;
 248
 249         for_each_possible_cpu(cpu)
 250                 qmap->mq_map[cpu] = 0;
 251 }
 252
 253 #endif