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