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 455