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 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 void blk_mq_submit_bio(struct bio *bio); 34 int blk_mq_poll(struct request_queue *q, blk_qc_t cookie, struct io_comp_batch *iob, 35 unsigned int flags); 36 void blk_mq_exit_queue(struct request_queue *q); 37 int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr); 38 void blk_mq_wake_waiters(struct request_queue *q); 39 bool blk_mq_dispatch_rq_list(struct blk_mq_hw_ctx *hctx, struct list_head *, 40 unsigned int); 41 void blk_mq_add_to_requeue_list(struct request *rq, bool at_head, 42 bool kick_requeue_list); 43 void blk_mq_flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, struct list_head *list); 44 struct request *blk_mq_dequeue_from_ctx(struct blk_mq_hw_ctx *hctx, 45 struct blk_mq_ctx *start); 46 void blk_mq_put_rq_ref(struct request *rq); 47 48 /* 49 * Internal helpers for allocating/freeing the request map 50 */ 51 void blk_mq_free_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags, 52 unsigned int hctx_idx); 53 void blk_mq_free_rq_map(struct blk_mq_tags *tags); 54 struct blk_mq_tags *blk_mq_alloc_map_and_rqs(struct blk_mq_tag_set *set, 55 unsigned int hctx_idx, unsigned int depth); 56 void blk_mq_free_map_and_rqs(struct blk_mq_tag_set *set, 57 struct blk_mq_tags *tags, 58 unsigned int hctx_idx); 59 /* 60 * Internal helpers for request insertion into sw queues 61 */ 62 void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq, 63 bool at_head); 64 void blk_mq_request_bypass_insert(struct request *rq, bool at_head, 65 bool run_queue); 66 void blk_mq_insert_requests(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx, 67 struct list_head *list); 68 void blk_mq_try_issue_list_directly(struct blk_mq_hw_ctx *hctx, 69 struct list_head *list); 70 71 /* 72 * CPU -> queue mappings 73 */ 74 extern int blk_mq_hw_queue_to_node(struct blk_mq_queue_map *qmap, unsigned int); 75 76 /* 77 * blk_mq_map_queue_type() - map (hctx_type,cpu) to hardware queue 78 * @q: request queue 79 * @type: the hctx type index 80 * @cpu: CPU 81 */ 82 static inline struct blk_mq_hw_ctx *blk_mq_map_queue_type(struct request_queue *q, 83 enum hctx_type type, 84 unsigned int cpu) 85 { 86 return xa_load(&q->hctx_table, q->tag_set->map[type].mq_map[cpu]); 87 } 88 89 static inline enum hctx_type blk_mq_get_hctx_type(unsigned int flags) 90 { 91 enum hctx_type type = HCTX_TYPE_DEFAULT; 92 93 /* 94 * The caller ensure that if REQ_POLLED, poll must be enabled. 95 */ 96 if (flags & REQ_POLLED) 97 type = HCTX_TYPE_POLL; 98 else if ((flags & REQ_OP_MASK) == REQ_OP_READ) 99 type = HCTX_TYPE_READ; 100 return type; 101 } 102 103 /* 104 * blk_mq_map_queue() - map (cmd_flags,type) to hardware queue 105 * @q: request queue 106 * @flags: request command flags 107 * @ctx: software queue cpu ctx 108 */ 109 static inline struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q, 110 unsigned int flags, 111 struct blk_mq_ctx *ctx) 112 { 113 return ctx->hctxs[blk_mq_get_hctx_type(flags)]; 114 } 115 116 /* 117 * sysfs helpers 118 */ 119 extern void blk_mq_sysfs_init(struct request_queue *q); 120 extern void blk_mq_sysfs_deinit(struct request_queue *q); 121 extern int __blk_mq_register_dev(struct device *dev, struct request_queue *q); 122 extern int blk_mq_sysfs_register(struct request_queue *q); 123 extern void blk_mq_sysfs_unregister(struct request_queue *q); 124 extern void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx); 125 void blk_mq_free_plug_rqs(struct blk_plug *plug); 126 void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule); 127 128 void blk_mq_cancel_work_sync(struct request_queue *q); 129 130 void blk_mq_release(struct request_queue *q); 131 132 static inline struct blk_mq_ctx *__blk_mq_get_ctx(struct request_queue *q, 133 unsigned int cpu) 134 { 135 return per_cpu_ptr(q->queue_ctx, cpu); 136 } 137 138 /* 139 * This assumes per-cpu software queueing queues. They could be per-node 140 * as well, for instance. For now this is hardcoded as-is. Note that we don't 141 * care about preemption, since we know the ctx's are persistent. This does 142 * mean that we can't rely on ctx always matching the currently running CPU. 143 */ 144 static inline struct blk_mq_ctx *blk_mq_get_ctx(struct request_queue *q) 145 { 146 return __blk_mq_get_ctx(q, raw_smp_processor_id()); 147 } 148 149 struct blk_mq_alloc_data { 150 /* input parameter */ 151 struct request_queue *q; 152 blk_mq_req_flags_t flags; 153 unsigned int shallow_depth; 154 unsigned int cmd_flags; 155 req_flags_t rq_flags; 156 157 /* allocate multiple requests/tags in one go */ 158 unsigned int nr_tags; 159 struct request **cached_rq; 160 161 /* input & output parameter */ 162 struct blk_mq_ctx *ctx; 163 struct blk_mq_hw_ctx *hctx; 164 }; 165 166 static inline bool blk_mq_is_shared_tags(unsigned int flags) 167 { 168 return flags & BLK_MQ_F_TAG_HCTX_SHARED; 169 } 170 171 static inline struct blk_mq_tags *blk_mq_tags_from_data(struct blk_mq_alloc_data *data) 172 { 173 if (!(data->rq_flags & RQF_ELV)) 174 return data->hctx->tags; 175 return data->hctx->sched_tags; 176 } 177 178 static inline bool blk_mq_hctx_stopped(struct blk_mq_hw_ctx *hctx) 179 { 180 return test_bit(BLK_MQ_S_STOPPED, &hctx->state); 181 } 182 183 static inline bool blk_mq_hw_queue_mapped(struct blk_mq_hw_ctx *hctx) 184 { 185 return hctx->nr_ctx && hctx->tags; 186 } 187 188 unsigned int blk_mq_in_flight(struct request_queue *q, 189 struct block_device *part); 190 void blk_mq_in_flight_rw(struct request_queue *q, struct block_device *part, 191 unsigned int inflight[2]); 192 193 static inline void blk_mq_put_dispatch_budget(struct request_queue *q, 194 int budget_token) 195 { 196 if (q->mq_ops->put_budget) 197 q->mq_ops->put_budget(q, budget_token); 198 } 199 200 static inline int blk_mq_get_dispatch_budget(struct request_queue *q) 201 { 202 if (q->mq_ops->get_budget) 203 return q->mq_ops->get_budget(q); 204 return 0; 205 } 206 207 static inline void blk_mq_set_rq_budget_token(struct request *rq, int token) 208 { 209 if (token < 0) 210 return; 211 212 if (rq->q->mq_ops->set_rq_budget_token) 213 rq->q->mq_ops->set_rq_budget_token(rq, token); 214 } 215 216 static inline int blk_mq_get_rq_budget_token(struct request *rq) 217 { 218 if (rq->q->mq_ops->get_rq_budget_token) 219 return rq->q->mq_ops->get_rq_budget_token(rq); 220 return -1; 221 } 222 223 static inline void __blk_mq_inc_active_requests(struct blk_mq_hw_ctx *hctx) 224 { 225 if (blk_mq_is_shared_tags(hctx->flags)) 226 atomic_inc(&hctx->queue->nr_active_requests_shared_tags); 227 else 228 atomic_inc(&hctx->nr_active); 229 } 230 231 static inline void __blk_mq_sub_active_requests(struct blk_mq_hw_ctx *hctx, 232 int val) 233 { 234 if (blk_mq_is_shared_tags(hctx->flags)) 235 atomic_sub(val, &hctx->queue->nr_active_requests_shared_tags); 236 else 237 atomic_sub(val, &hctx->nr_active); 238 } 239 240 static inline void __blk_mq_dec_active_requests(struct blk_mq_hw_ctx *hctx) 241 { 242 __blk_mq_sub_active_requests(hctx, 1); 243 } 244 245 static inline int __blk_mq_active_requests(struct blk_mq_hw_ctx *hctx) 246 { 247 if (blk_mq_is_shared_tags(hctx->flags)) 248 return atomic_read(&hctx->queue->nr_active_requests_shared_tags); 249 return atomic_read(&hctx->nr_active); 250 } 251 static inline void __blk_mq_put_driver_tag(struct blk_mq_hw_ctx *hctx, 252 struct request *rq) 253 { 254 blk_mq_put_tag(hctx->tags, rq->mq_ctx, rq->tag); 255 rq->tag = BLK_MQ_NO_TAG; 256 257 if (rq->rq_flags & RQF_MQ_INFLIGHT) { 258 rq->rq_flags &= ~RQF_MQ_INFLIGHT; 259 __blk_mq_dec_active_requests(hctx); 260 } 261 } 262 263 static inline void blk_mq_put_driver_tag(struct request *rq) 264 { 265 if (rq->tag == BLK_MQ_NO_TAG || rq->internal_tag == BLK_MQ_NO_TAG) 266 return; 267 268 __blk_mq_put_driver_tag(rq->mq_hctx, rq); 269 } 270 271 bool __blk_mq_get_driver_tag(struct blk_mq_hw_ctx *hctx, struct request *rq); 272 273 static inline bool blk_mq_get_driver_tag(struct request *rq) 274 { 275 struct blk_mq_hw_ctx *hctx = rq->mq_hctx; 276 277 if (rq->tag != BLK_MQ_NO_TAG && 278 !(hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED)) { 279 hctx->tags->rqs[rq->tag] = rq; 280 return true; 281 } 282 283 return __blk_mq_get_driver_tag(hctx, rq); 284 } 285 286 static inline void blk_mq_clear_mq_map(struct blk_mq_queue_map *qmap) 287 { 288 int cpu; 289 290 for_each_possible_cpu(cpu) 291 qmap->mq_map[cpu] = 0; 292 } 293 294 /* 295 * blk_mq_plug() - Get caller context plug 296 * @q: request queue 297 * @bio : the bio being submitted by the caller context 298 * 299 * Plugging, by design, may delay the insertion of BIOs into the elevator in 300 * order to increase BIO merging opportunities. This however can cause BIO 301 * insertion order to change from the order in which submit_bio() is being 302 * executed in the case of multiple contexts concurrently issuing BIOs to a 303 * device, even if these context are synchronized to tightly control BIO issuing 304 * order. While this is not a problem with regular block devices, this ordering 305 * change can cause write BIO failures with zoned block devices as these 306 * require sequential write patterns to zones. Prevent this from happening by 307 * ignoring the plug state of a BIO issuing context if the target request queue 308 * is for a zoned block device and the BIO to plug is a write operation. 309 * 310 * Return current->plug if the bio can be plugged and NULL otherwise 311 */ 312 static inline struct blk_plug *blk_mq_plug(struct request_queue *q, 313 struct bio *bio) 314 { 315 /* 316 * For regular block devices or read operations, use the context plug 317 * which may be NULL if blk_start_plug() was not executed. 318 */ 319 if (!blk_queue_is_zoned(q) || !op_is_write(bio_op(bio))) 320 return current->plug; 321 322 /* Zoned block device write operation case: do not plug the BIO */ 323 return NULL; 324 } 325 326 /* Free all requests on the list */ 327 static inline void blk_mq_free_requests(struct list_head *list) 328 { 329 while (!list_empty(list)) { 330 struct request *rq = list_entry_rq(list->next); 331 332 list_del_init(&rq->queuelist); 333 blk_mq_free_request(rq); 334 } 335 } 336 337 /* 338 * For shared tag users, we track the number of currently active users 339 * and attempt to provide a fair share of the tag depth for each of them. 340 */ 341 static inline bool hctx_may_queue(struct blk_mq_hw_ctx *hctx, 342 struct sbitmap_queue *bt) 343 { 344 unsigned int depth, users; 345 346 if (!hctx || !(hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED)) 347 return true; 348 349 /* 350 * Don't try dividing an ant 351 */ 352 if (bt->sb.depth == 1) 353 return true; 354 355 if (blk_mq_is_shared_tags(hctx->flags)) { 356 struct request_queue *q = hctx->queue; 357 358 if (!test_bit(QUEUE_FLAG_HCTX_ACTIVE, &q->queue_flags)) 359 return true; 360 } else { 361 if (!test_bit(BLK_MQ_S_TAG_ACTIVE, &hctx->state)) 362 return true; 363 } 364 365 users = atomic_read(&hctx->tags->active_queues); 366 367 if (!users) 368 return true; 369 370 /* 371 * Allow at least some tags 372 */ 373 depth = max((bt->sb.depth + users - 1) / users, 4U); 374 return __blk_mq_active_requests(hctx) < depth; 375 } 376 377 /* run the code block in @dispatch_ops with rcu/srcu read lock held */ 378 #define __blk_mq_run_dispatch_ops(q, check_sleep, dispatch_ops) \ 379 do { \ 380 if (!blk_queue_has_srcu(q)) { \ 381 rcu_read_lock(); \ 382 (dispatch_ops); \ 383 rcu_read_unlock(); \ 384 } else { \ 385 int srcu_idx; \ 386 \ 387 might_sleep_if(check_sleep); \ 388 srcu_idx = srcu_read_lock((q)->srcu); \ 389 (dispatch_ops); \ 390 srcu_read_unlock((q)->srcu, srcu_idx); \ 391 } \ 392 } while (0) 393 394 #define blk_mq_run_dispatch_ops(q, dispatch_ops) \ 395 __blk_mq_run_dispatch_ops(q, true, dispatch_ops) \ 396 397 #endif 398