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, unsigned int flags, int node); 167 void blk_mq_free_tags(struct blk_mq_tags *tags); 168 169 unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data); 170 unsigned long blk_mq_get_tags(struct blk_mq_alloc_data *data, int nr_tags, 171 unsigned int *offset); 172 void blk_mq_put_tag(struct blk_mq_tags *tags, struct blk_mq_ctx *ctx, 173 unsigned int tag); 174 void blk_mq_put_tags(struct blk_mq_tags *tags, int *tag_array, int nr_tags); 175 int blk_mq_tag_update_depth(struct blk_mq_hw_ctx *hctx, 176 struct blk_mq_tags **tags, unsigned int depth, bool can_grow); 177 void blk_mq_tag_resize_shared_tags(struct blk_mq_tag_set *set, 178 unsigned int size); 179 void blk_mq_tag_update_sched_shared_tags(struct request_queue *q); 180 181 void blk_mq_tag_wakeup_all(struct blk_mq_tags *tags, bool); 182 void blk_mq_queue_tag_busy_iter(struct request_queue *q, busy_tag_iter_fn *fn, 183 void *priv); 184 void blk_mq_all_tag_iter(struct blk_mq_tags *tags, busy_tag_iter_fn *fn, 185 void *priv); 186 187 static inline struct sbq_wait_state *bt_wait_ptr(struct sbitmap_queue *bt, 188 struct blk_mq_hw_ctx *hctx) 189 { 190 if (!hctx) 191 return &bt->ws[0]; 192 return sbq_wait_ptr(bt, &hctx->wait_index); 193 } 194 195 void __blk_mq_tag_busy(struct blk_mq_hw_ctx *); 196 void __blk_mq_tag_idle(struct blk_mq_hw_ctx *); 197 198 static inline void blk_mq_tag_busy(struct blk_mq_hw_ctx *hctx) 199 { 200 if (hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED) 201 __blk_mq_tag_busy(hctx); 202 } 203 204 static inline void blk_mq_tag_idle(struct blk_mq_hw_ctx *hctx) 205 { 206 if (hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED) 207 __blk_mq_tag_idle(hctx); 208 } 209 210 static inline bool blk_mq_tag_is_reserved(struct blk_mq_tags *tags, 211 unsigned int tag) 212 { 213 return tag < tags->nr_reserved_tags; 214 } 215 216 static inline bool blk_mq_is_shared_tags(unsigned int flags) 217 { 218 return flags & BLK_MQ_F_TAG_HCTX_SHARED; 219 } 220 221 static inline struct blk_mq_tags *blk_mq_tags_from_data(struct blk_mq_alloc_data *data) 222 { 223 if (data->rq_flags & RQF_SCHED_TAGS) 224 return data->hctx->sched_tags; 225 return data->hctx->tags; 226 } 227 228 static inline bool blk_mq_hctx_stopped(struct blk_mq_hw_ctx *hctx) 229 { 230 /* Fast path: hardware queue is not stopped most of the time. */ 231 if (likely(!test_bit(BLK_MQ_S_STOPPED, &hctx->state))) 232 return false; 233 234 /* 235 * This barrier is used to order adding of dispatch list before and 236 * the test of BLK_MQ_S_STOPPED below. Pairs with the memory barrier 237 * in blk_mq_start_stopped_hw_queue() so that dispatch code could 238 * either see BLK_MQ_S_STOPPED is cleared or dispatch list is not 239 * empty to avoid missing dispatching requests. 240 */ 241 smp_mb(); 242 243 return test_bit(BLK_MQ_S_STOPPED, &hctx->state); 244 } 245 246 static inline bool blk_mq_hw_queue_mapped(struct blk_mq_hw_ctx *hctx) 247 { 248 return hctx->nr_ctx && hctx->tags; 249 } 250 251 unsigned int blk_mq_in_flight(struct request_queue *q, 252 struct block_device *part); 253 void blk_mq_in_flight_rw(struct request_queue *q, struct block_device *part, 254 unsigned int inflight[2]); 255 256 static inline void blk_mq_put_dispatch_budget(struct request_queue *q, 257 int budget_token) 258 { 259 if (q->mq_ops->put_budget) 260 q->mq_ops->put_budget(q, budget_token); 261 } 262 263 static inline int blk_mq_get_dispatch_budget(struct request_queue *q) 264 { 265 if (q->mq_ops->get_budget) 266 return q->mq_ops->get_budget(q); 267 return 0; 268 } 269 270 static inline void blk_mq_set_rq_budget_token(struct request *rq, int token) 271 { 272 if (token < 0) 273 return; 274 275 if (rq->q->mq_ops->set_rq_budget_token) 276 rq->q->mq_ops->set_rq_budget_token(rq, token); 277 } 278 279 static inline int blk_mq_get_rq_budget_token(struct request *rq) 280 { 281 if (rq->q->mq_ops->get_rq_budget_token) 282 return rq->q->mq_ops->get_rq_budget_token(rq); 283 return -1; 284 } 285 286 static inline void __blk_mq_add_active_requests(struct blk_mq_hw_ctx *hctx, 287 int val) 288 { 289 if (blk_mq_is_shared_tags(hctx->flags)) 290 atomic_add(val, &hctx->queue->nr_active_requests_shared_tags); 291 else 292 atomic_add(val, &hctx->nr_active); 293 } 294 295 static inline void __blk_mq_inc_active_requests(struct blk_mq_hw_ctx *hctx) 296 { 297 __blk_mq_add_active_requests(hctx, 1); 298 } 299 300 static inline void __blk_mq_sub_active_requests(struct blk_mq_hw_ctx *hctx, 301 int val) 302 { 303 if (blk_mq_is_shared_tags(hctx->flags)) 304 atomic_sub(val, &hctx->queue->nr_active_requests_shared_tags); 305 else 306 atomic_sub(val, &hctx->nr_active); 307 } 308 309 static inline void __blk_mq_dec_active_requests(struct blk_mq_hw_ctx *hctx) 310 { 311 __blk_mq_sub_active_requests(hctx, 1); 312 } 313 314 static inline void blk_mq_add_active_requests(struct blk_mq_hw_ctx *hctx, 315 int val) 316 { 317 if (hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED) 318 __blk_mq_add_active_requests(hctx, val); 319 } 320 321 static inline void blk_mq_inc_active_requests(struct blk_mq_hw_ctx *hctx) 322 { 323 if (hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED) 324 __blk_mq_inc_active_requests(hctx); 325 } 326 327 static inline void blk_mq_sub_active_requests(struct blk_mq_hw_ctx *hctx, 328 int val) 329 { 330 if (hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED) 331 __blk_mq_sub_active_requests(hctx, val); 332 } 333 334 static inline void blk_mq_dec_active_requests(struct blk_mq_hw_ctx *hctx) 335 { 336 if (hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED) 337 __blk_mq_dec_active_requests(hctx); 338 } 339 340 static inline int __blk_mq_active_requests(struct blk_mq_hw_ctx *hctx) 341 { 342 if (blk_mq_is_shared_tags(hctx->flags)) 343 return atomic_read(&hctx->queue->nr_active_requests_shared_tags); 344 return atomic_read(&hctx->nr_active); 345 } 346 static inline void __blk_mq_put_driver_tag(struct blk_mq_hw_ctx *hctx, 347 struct request *rq) 348 { 349 blk_mq_dec_active_requests(hctx); 350 blk_mq_put_tag(hctx->tags, rq->mq_ctx, rq->tag); 351 rq->tag = BLK_MQ_NO_TAG; 352 } 353 354 static inline void blk_mq_put_driver_tag(struct request *rq) 355 { 356 if (rq->tag == BLK_MQ_NO_TAG || rq->internal_tag == BLK_MQ_NO_TAG) 357 return; 358 359 __blk_mq_put_driver_tag(rq->mq_hctx, rq); 360 } 361 362 bool __blk_mq_alloc_driver_tag(struct request *rq); 363 364 static inline bool blk_mq_get_driver_tag(struct request *rq) 365 { 366 if (rq->tag == BLK_MQ_NO_TAG && !__blk_mq_alloc_driver_tag(rq)) 367 return false; 368 369 return true; 370 } 371 372 static inline void blk_mq_clear_mq_map(struct blk_mq_queue_map *qmap) 373 { 374 int cpu; 375 376 for_each_possible_cpu(cpu) 377 qmap->mq_map[cpu] = 0; 378 } 379 380 /* Free all requests on the list */ 381 static inline void blk_mq_free_requests(struct list_head *list) 382 { 383 while (!list_empty(list)) { 384 struct request *rq = list_entry_rq(list->next); 385 386 list_del_init(&rq->queuelist); 387 blk_mq_free_request(rq); 388 } 389 } 390 391 /* 392 * For shared tag users, we track the number of currently active users 393 * and attempt to provide a fair share of the tag depth for each of them. 394 */ 395 static inline bool hctx_may_queue(struct blk_mq_hw_ctx *hctx, 396 struct sbitmap_queue *bt) 397 { 398 unsigned int depth, users; 399 400 if (!hctx || !(hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED)) 401 return true; 402 403 /* 404 * Don't try dividing an ant 405 */ 406 if (bt->sb.depth == 1) 407 return true; 408 409 if (blk_mq_is_shared_tags(hctx->flags)) { 410 struct request_queue *q = hctx->queue; 411 412 if (!test_bit(QUEUE_FLAG_HCTX_ACTIVE, &q->queue_flags)) 413 return true; 414 } else { 415 if (!test_bit(BLK_MQ_S_TAG_ACTIVE, &hctx->state)) 416 return true; 417 } 418 419 users = READ_ONCE(hctx->tags->active_queues); 420 if (!users) 421 return true; 422 423 /* 424 * Allow at least some tags 425 */ 426 depth = max((bt->sb.depth + users - 1) / users, 4U); 427 return __blk_mq_active_requests(hctx) < depth; 428 } 429 430 /* run the code block in @dispatch_ops with rcu/srcu read lock held */ 431 #define __blk_mq_run_dispatch_ops(q, check_sleep, dispatch_ops) \ 432 do { \ 433 if ((q)->tag_set->flags & BLK_MQ_F_BLOCKING) { \ 434 struct blk_mq_tag_set *__tag_set = (q)->tag_set; \ 435 int srcu_idx; \ 436 \ 437 might_sleep_if(check_sleep); \ 438 srcu_idx = srcu_read_lock(__tag_set->srcu); \ 439 (dispatch_ops); \ 440 srcu_read_unlock(__tag_set->srcu, srcu_idx); \ 441 } else { \ 442 rcu_read_lock(); \ 443 (dispatch_ops); \ 444 rcu_read_unlock(); \ 445 } \ 446 } while (0) 447 448 #define blk_mq_run_dispatch_ops(q, dispatch_ops) \ 449 __blk_mq_run_dispatch_ops(q, true, dispatch_ops) \ 450 451 static inline bool blk_mq_can_poll(struct request_queue *q) 452 { 453 return (q->limits.features & BLK_FEAT_POLL) && 454 q->tag_set->map[HCTX_TYPE_POLL].nr_queues; 455 } 456 457 #endif 458