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 <linux/blk-mq.h>
   6 #include "blk-stat.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         struct blk_mq_hw_ctx    *hctxs[HCTX_MAX_TYPES];
  27
  28         struct request_queue    *queue;
  29         struct blk_mq_ctxs      *ctxs;
  30         struct kobject          kobj;
  31 } ____cacheline_aligned_in_smp;
  32
  33 enum {
  34         BLK_MQ_NO_TAG           = -1U,
  35         BLK_MQ_TAG_MIN          = 1,
  36         BLK_MQ_TAG_MAX          = BLK_MQ_NO_TAG - 1,
  37 };
  38
  39 #define BLK_MQ_CPU_WORK_BATCH   (8)
  40
  41 typedef unsigned int __bitwise blk_insert_t;
  42 #define BLK_MQ_INSERT_AT_HEAD           ((__force blk_insert_t)0x01)
  43
  44 void blk_mq_submit_bio(struct bio *bio);
  45 int blk_mq_poll(struct request_queue *q, blk_qc_t cookie, struct io_comp_batch *iob,
  46                 unsigned int flags);
  47 void blk_mq_exit_queue(struct request_queue *q);
  48 int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr);
  49 void blk_mq_wake_waiters(struct request_queue *q);
  50 bool blk_mq_dispatch_rq_list(struct blk_mq_hw_ctx *hctx, struct list_head *,
  51                              unsigned int);
  52 void blk_mq_flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, struct list_head *list);
  53 struct request *blk_mq_dequeue_from_ctx(struct blk_mq_hw_ctx *hctx,
  54                                         struct blk_mq_ctx *start);
  55 void blk_mq_put_rq_ref(struct request *rq);
  56
  57 /*
  58  * Internal helpers for allocating/freeing the request map
  59  */
  60 void blk_mq_free_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
  61                      unsigned int hctx_idx);
  62 void blk_mq_free_rq_map(struct blk_mq_tags *tags);
  63 struct blk_mq_tags *blk_mq_alloc_map_and_rqs(struct blk_mq_tag_set *set,
  64                                 unsigned int hctx_idx, unsigned int depth);
  65 void blk_mq_free_map_and_rqs(struct blk_mq_tag_set *set,
  66                              struct blk_mq_tags *tags,
  67                              unsigned int hctx_idx);
  68
  69 /*
  70  * CPU -> queue mappings
  71  */
  72 extern int blk_mq_hw_queue_to_node(struct blk_mq_queue_map *qmap, unsigned int);
  73
  74 /*
  75  * blk_mq_map_queue_type() - map (hctx_type,cpu) to hardware queue
  76  * @q: request queue
  77  * @type: the hctx type index
  78  * @cpu: CPU
  79  */
  80 static inline struct blk_mq_hw_ctx *blk_mq_map_queue_type(struct request_queue *q,
  81                                                           enum hctx_type type,
  82                                                           unsigned int cpu)
  83 {
  84         return xa_load(&q->hctx_table, q->tag_set->map[type].mq_map[cpu]);
  85 }
  86
  87 static inline enum hctx_type blk_mq_get_hctx_type(blk_opf_t opf)
  88 {
  89         enum hctx_type type = HCTX_TYPE_DEFAULT;
  90
  91         /*
  92          * The caller ensure that if REQ_POLLED, poll must be enabled.
  93          */
  94         if (opf & REQ_POLLED)
  95                 type = HCTX_TYPE_POLL;
  96         else if ((opf & REQ_OP_MASK) == REQ_OP_READ)
  97                 type = HCTX_TYPE_READ;
  98         return type;
  99 }
 100
 101 /*
 102  * blk_mq_map_queue() - map (cmd_flags,type) to hardware queue
 103  * @q: request queue
 104  * @opf: operation type (REQ_OP_*) and flags (e.g. REQ_POLLED).
 105  * @ctx: software queue cpu ctx
 106  */
 107 static inline struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q,
 108                                                      blk_opf_t opf,
 109                                                      struct blk_mq_ctx *ctx)
 110 {
 111         return ctx->hctxs[blk_mq_get_hctx_type(opf)];
 112 }
 113
 114 /*
 115  * sysfs helpers
 116  */
 117 extern void blk_mq_sysfs_init(struct request_queue *q);
 118 extern void blk_mq_sysfs_deinit(struct request_queue *q);
 119 int blk_mq_sysfs_register(struct gendisk *disk);
 120 void blk_mq_sysfs_unregister(struct gendisk *disk);
 121 int blk_mq_sysfs_register_hctxs(struct request_queue *q);
 122 void blk_mq_sysfs_unregister_hctxs(struct request_queue *q);
 123 extern void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx);
 124 void blk_mq_free_plug_rqs(struct blk_plug *plug);
 125 void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule);
 126
 127 void blk_mq_cancel_work_sync(struct request_queue *q);
 128
 129 void blk_mq_release(struct request_queue *q);
 130
 131 static inline struct blk_mq_ctx *__blk_mq_get_ctx(struct request_queue *q,
 132                                            unsigned int cpu)
 133 {
 134         return per_cpu_ptr(q->queue_ctx, cpu);
 135 }
 136
 137 /*
 138  * This assumes per-cpu software queueing queues. They could be per-node
 139  * as well, for instance. For now this is hardcoded as-is. Note that we don't
 140  * care about preemption, since we know the ctx's are persistent. This does
 141  * mean that we can't rely on ctx always matching the currently running CPU.
 142  */
 143 static inline struct blk_mq_ctx *blk_mq_get_ctx(struct request_queue *q)
 144 {
 145         return __blk_mq_get_ctx(q, raw_smp_processor_id());
 146 }
 147
 148 struct blk_mq_alloc_data {
 149         /* input parameter */
 150         struct request_queue *q;
 151         blk_mq_req_flags_t flags;
 152         unsigned int shallow_depth;
 153         blk_opf_t cmd_flags;
 154         req_flags_t rq_flags;
 155
 156         /* allocate multiple requests/tags in one go */
 157         unsigned int nr_tags;
 158         struct rq_list *cached_rqs;
 159
 160         /* input & output parameter */
 161         struct blk_mq_ctx *ctx;
 162         struct blk_mq_hw_ctx *hctx;
 163 };
 164
 165 struct blk_mq_tags *blk_mq_init_tags(unsigned int nr_tags,
 166                 unsigned int reserved_tags, int node, int alloc_policy);
 167 void blk_mq_free_tags(struct blk_mq_tags *tags);
 168 int blk_mq_init_bitmaps(struct sbitmap_queue *bitmap_tags,
 169                 struct sbitmap_queue *breserved_tags, unsigned int queue_depth,
 170                 unsigned int reserved, int node, int alloc_policy);
 171
 172 unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data);
 173 unsigned long blk_mq_get_tags(struct blk_mq_alloc_data *data, int nr_tags,
 174                 unsigned int *offset);
 175 void blk_mq_put_tag(struct blk_mq_tags *tags, struct blk_mq_ctx *ctx,
 176                 unsigned int tag);
 177 void blk_mq_put_tags(struct blk_mq_tags *tags, int *tag_array, int nr_tags);
 178 int blk_mq_tag_update_depth(struct blk_mq_hw_ctx *hctx,
 179                 struct blk_mq_tags **tags, unsigned int depth, bool can_grow);
 180 void blk_mq_tag_resize_shared_tags(struct blk_mq_tag_set *set,
 181                 unsigned int size);
 182 void blk_mq_tag_update_sched_shared_tags(struct request_queue *q);
 183
 184 void blk_mq_tag_wakeup_all(struct blk_mq_tags *tags, bool);
 185 void blk_mq_queue_tag_busy_iter(struct request_queue *q, busy_tag_iter_fn *fn,
 186                 void *priv);
 187 void blk_mq_all_tag_iter(struct blk_mq_tags *tags, busy_tag_iter_fn *fn,
 188                 void *priv);
 189
 190 static inline struct sbq_wait_state *bt_wait_ptr(struct sbitmap_queue *bt,
 191                                                  struct blk_mq_hw_ctx *hctx)
 192 {
 193         if (!hctx)
 194                 return &bt->ws[0];
 195         return sbq_wait_ptr(bt, &hctx->wait_index);
 196 }
 197
 198 void __blk_mq_tag_busy(struct blk_mq_hw_ctx *);
 199 void __blk_mq_tag_idle(struct blk_mq_hw_ctx *);
 200
 201 static inline void blk_mq_tag_busy(struct blk_mq_hw_ctx *hctx)
 202 {
 203         if (hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED)
 204                 __blk_mq_tag_busy(hctx);
 205 }
 206
 207 static inline void blk_mq_tag_idle(struct blk_mq_hw_ctx *hctx)
 208 {
 209         if (hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED)
 210                 __blk_mq_tag_idle(hctx);
 211 }
 212
 213 static inline bool blk_mq_tag_is_reserved(struct blk_mq_tags *tags,
 214                                           unsigned int tag)
 215 {
 216         return tag < tags->nr_reserved_tags;
 217 }
 218
 219 static inline bool blk_mq_is_shared_tags(unsigned int flags)
 220 {
 221         return flags & BLK_MQ_F_TAG_HCTX_SHARED;
 222 }
 223
 224 static inline struct blk_mq_tags *blk_mq_tags_from_data(struct blk_mq_alloc_data *data)
 225 {
 226         if (data->rq_flags & RQF_SCHED_TAGS)
 227                 return data->hctx->sched_tags;
 228         return data->hctx->tags;
 229 }
 230
 231 static inline bool blk_mq_hctx_stopped(struct blk_mq_hw_ctx *hctx)
 232 {
 233         /* Fast path: hardware queue is not stopped most of the time. */
 234         if (likely(!test_bit(BLK_MQ_S_STOPPED, &hctx->state)))
 235                 return false;
 236
 237         /*
 238          * This barrier is used to order adding of dispatch list before and
 239          * the test of BLK_MQ_S_STOPPED below. Pairs with the memory barrier
 240          * in blk_mq_start_stopped_hw_queue() so that dispatch code could
 241          * either see BLK_MQ_S_STOPPED is cleared or dispatch list is not
 242          * empty to avoid missing dispatching requests.
 243          */
 244         smp_mb();
 245
 246         return test_bit(BLK_MQ_S_STOPPED, &hctx->state);
 247 }
 248
 249 static inline bool blk_mq_hw_queue_mapped(struct blk_mq_hw_ctx *hctx)
 250 {
 251         return hctx->nr_ctx && hctx->tags;
 252 }
 253
 254 unsigned int blk_mq_in_flight(struct request_queue *q,
 255                 struct block_device *part);
 256 void blk_mq_in_flight_rw(struct request_queue *q, struct block_device *part,
 257                 unsigned int inflight[2]);
 258
 259 static inline void blk_mq_put_dispatch_budget(struct request_queue *q,
 260                                               int budget_token)
 261 {
 262         if (q->mq_ops->put_budget)
 263                 q->mq_ops->put_budget(q, budget_token);
 264 }
 265
 266 static inline int blk_mq_get_dispatch_budget(struct request_queue *q)
 267 {
 268         if (q->mq_ops->get_budget)
 269                 return q->mq_ops->get_budget(q);
 270         return 0;
 271 }
 272
 273 static inline void blk_mq_set_rq_budget_token(struct request *rq, int token)
 274 {
 275         if (token < 0)
 276                 return;
 277
 278         if (rq->q->mq_ops->set_rq_budget_token)
 279                 rq->q->mq_ops->set_rq_budget_token(rq, token);
 280 }
 281
 282 static inline int blk_mq_get_rq_budget_token(struct request *rq)
 283 {
 284         if (rq->q->mq_ops->get_rq_budget_token)
 285                 return rq->q->mq_ops->get_rq_budget_token(rq);
 286         return -1;
 287 }
 288
 289 static inline void __blk_mq_add_active_requests(struct blk_mq_hw_ctx *hctx,
 290                                                 int val)
 291 {
 292         if (blk_mq_is_shared_tags(hctx->flags))
 293                 atomic_add(val, &hctx->queue->nr_active_requests_shared_tags);
 294         else
 295                 atomic_add(val, &hctx->nr_active);
 296 }
 297
 298 static inline void __blk_mq_inc_active_requests(struct blk_mq_hw_ctx *hctx)
 299 {
 300         __blk_mq_add_active_requests(hctx, 1);
 301 }
 302
 303 static inline void __blk_mq_sub_active_requests(struct blk_mq_hw_ctx *hctx,
 304                 int val)
 305 {
 306         if (blk_mq_is_shared_tags(hctx->flags))
 307                 atomic_sub(val, &hctx->queue->nr_active_requests_shared_tags);
 308         else
 309                 atomic_sub(val, &hctx->nr_active);
 310 }
 311
 312 static inline void __blk_mq_dec_active_requests(struct blk_mq_hw_ctx *hctx)
 313 {
 314         __blk_mq_sub_active_requests(hctx, 1);
 315 }
 316
 317 static inline void blk_mq_add_active_requests(struct blk_mq_hw_ctx *hctx,
 318                                               int val)
 319 {
 320         if (hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED)
 321                 __blk_mq_add_active_requests(hctx, val);
 322 }
 323
 324 static inline void blk_mq_inc_active_requests(struct blk_mq_hw_ctx *hctx)
 325 {
 326         if (hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED)
 327                 __blk_mq_inc_active_requests(hctx);
 328 }
 329
 330 static inline void blk_mq_sub_active_requests(struct blk_mq_hw_ctx *hctx,
 331                                               int val)
 332 {
 333         if (hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED)
 334                 __blk_mq_sub_active_requests(hctx, val);
 335 }
 336
 337 static inline void blk_mq_dec_active_requests(struct blk_mq_hw_ctx *hctx)
 338 {
 339         if (hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED)
 340                 __blk_mq_dec_active_requests(hctx);
 341 }
 342
 343 static inline int __blk_mq_active_requests(struct blk_mq_hw_ctx *hctx)
 344 {
 345         if (blk_mq_is_shared_tags(hctx->flags))
 346                 return atomic_read(&hctx->queue->nr_active_requests_shared_tags);
 347         return atomic_read(&hctx->nr_active);
 348 }
 349 static inline void __blk_mq_put_driver_tag(struct blk_mq_hw_ctx *hctx,
 350                                            struct request *rq)
 351 {
 352         blk_mq_dec_active_requests(hctx);
 353         blk_mq_put_tag(hctx->tags, rq->mq_ctx, rq->tag);
 354         rq->tag = BLK_MQ_NO_TAG;
 355 }
 356
 357 static inline void blk_mq_put_driver_tag(struct request *rq)
 358 {
 359         if (rq->tag == BLK_MQ_NO_TAG || rq->internal_tag == BLK_MQ_NO_TAG)
 360                 return;
 361
 362         __blk_mq_put_driver_tag(rq->mq_hctx, rq);
 363 }
 364
 365 bool __blk_mq_alloc_driver_tag(struct request *rq);
 366
 367 static inline bool blk_mq_get_driver_tag(struct request *rq)
 368 {
 369         if (rq->tag == BLK_MQ_NO_TAG && !__blk_mq_alloc_driver_tag(rq))
 370                 return false;
 371
 372         return true;
 373 }
 374
 375 static inline void blk_mq_clear_mq_map(struct blk_mq_queue_map *qmap)
 376 {
 377         int cpu;
 378
 379         for_each_possible_cpu(cpu)
 380                 qmap->mq_map[cpu] = 0;
 381 }
 382
 383 /* Free all requests on the list */
 384 static inline void blk_mq_free_requests(struct list_head *list)
 385 {
 386         while (!list_empty(list)) {
 387                 struct request *rq = list_entry_rq(list->next);
 388
 389                 list_del_init(&rq->queuelist);
 390                 blk_mq_free_request(rq);
 391         }
 392 }
 393
 394 /*
 395  * For shared tag users, we track the number of currently active users
 396  * and attempt to provide a fair share of the tag depth for each of them.
 397  */
 398 static inline bool hctx_may_queue(struct blk_mq_hw_ctx *hctx,
 399                                   struct sbitmap_queue *bt)
 400 {
 401         unsigned int depth, users;
 402
 403         if (!hctx || !(hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED))
 404                 return true;
 405
 406         /*
 407          * Don't try dividing an ant
 408          */
 409         if (bt->sb.depth == 1)
 410                 return true;
 411
 412         if (blk_mq_is_shared_tags(hctx->flags)) {
 413                 struct request_queue *q = hctx->queue;
 414
 415                 if (!test_bit(QUEUE_FLAG_HCTX_ACTIVE, &q->queue_flags))
 416                         return true;
 417         } else {
 418                 if (!test_bit(BLK_MQ_S_TAG_ACTIVE, &hctx->state))
 419                         return true;
 420         }
 421
 422         users = READ_ONCE(hctx->tags->active_queues);
 423         if (!users)
 424                 return true;
 425
 426         /*
 427          * Allow at least some tags
 428          */
 429         depth = max((bt->sb.depth + users - 1) / users, 4U);
 430         return __blk_mq_active_requests(hctx) < depth;
 431 }
 432
 433 /* run the code block in @dispatch_ops with rcu/srcu read lock held */
 434 #define __blk_mq_run_dispatch_ops(q, check_sleep, dispatch_ops) \
 435 do {                                                            \
 436         if ((q)->tag_set->flags & BLK_MQ_F_BLOCKING) {          \
 437                 struct blk_mq_tag_set *__tag_set = (q)->tag_set; \
 438                 int srcu_idx;                                   \
 439                                                                 \
 440                 might_sleep_if(check_sleep);                    \
 441                 srcu_idx = srcu_read_lock(__tag_set->srcu);     \
 442                 (dispatch_ops);                                 \
 443                 srcu_read_unlock(__tag_set->srcu, srcu_idx);    \
 444         } else {                                                \
 445                 rcu_read_lock();                                \
 446                 (dispatch_ops);                                 \
 447                 rcu_read_unlock();                              \
 448         }                                                       \
 449 } while (0)
 450
 451 #define blk_mq_run_dispatch_ops(q, dispatch_ops)                \
 452         __blk_mq_run_dispatch_ops(q, true, dispatch_ops)        \
 453
 454 #endif