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 /* incremented at dispatch time */ 29 unsigned long rq_dispatched[2]; 30 unsigned long rq_merged; 31 32 /* incremented at completion time */ 33 unsigned long ____cacheline_aligned_in_smp rq_completed[2]; 34 35 struct request_queue *queue; 36 struct blk_mq_ctxs *ctxs; 37 struct kobject kobj; 38 } ____cacheline_aligned_in_smp; 39 40 void blk_mq_exit_queue(struct request_queue *q); 41 int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr); 42 void blk_mq_wake_waiters(struct request_queue *q); 43 bool blk_mq_dispatch_rq_list(struct blk_mq_hw_ctx *hctx, struct list_head *, 44 unsigned int); 45 void blk_mq_add_to_requeue_list(struct request *rq, bool at_head, 46 bool kick_requeue_list); 47 void blk_mq_flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, struct list_head *list); 48 struct request *blk_mq_dequeue_from_ctx(struct blk_mq_hw_ctx *hctx, 49 struct blk_mq_ctx *start); 50 void blk_mq_put_rq_ref(struct request *rq); 51 52 /* 53 * Internal helpers for allocating/freeing the request map 54 */ 55 void blk_mq_free_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags, 56 unsigned int hctx_idx); 57 void blk_mq_free_rq_map(struct blk_mq_tags *tags, unsigned int flags); 58 struct blk_mq_tags *blk_mq_alloc_rq_map(struct blk_mq_tag_set *set, 59 unsigned int hctx_idx, 60 unsigned int nr_tags, 61 unsigned int reserved_tags, 62 unsigned int flags); 63 int blk_mq_alloc_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags, 64 unsigned int hctx_idx, unsigned int depth); 65 66 /* 67 * Internal helpers for request insertion into sw queues 68 */ 69 void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq, 70 bool at_head); 71 void blk_mq_request_bypass_insert(struct request *rq, bool at_head, 72 bool run_queue); 73 void blk_mq_insert_requests(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx, 74 struct list_head *list); 75 76 /* Used by blk_insert_cloned_request() to issue request directly */ 77 blk_status_t blk_mq_request_issue_directly(struct request *rq, bool last); 78 void blk_mq_try_issue_list_directly(struct blk_mq_hw_ctx *hctx, 79 struct list_head *list); 80 81 /* 82 * CPU -> queue mappings 83 */ 84 extern int blk_mq_hw_queue_to_node(struct blk_mq_queue_map *qmap, unsigned int); 85 86 /* 87 * blk_mq_map_queue_type() - map (hctx_type,cpu) to hardware queue 88 * @q: request queue 89 * @type: the hctx type index 90 * @cpu: CPU 91 */ 92 static inline struct blk_mq_hw_ctx *blk_mq_map_queue_type(struct request_queue *q, 93 enum hctx_type type, 94 unsigned int cpu) 95 { 96 return q->queue_hw_ctx[q->tag_set->map[type].mq_map[cpu]]; 97 } 98 99 /* 100 * blk_mq_map_queue() - map (cmd_flags,type) to hardware queue 101 * @q: request queue 102 * @flags: request command flags 103 * @ctx: software queue cpu ctx 104 */ 105 static inline struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q, 106 unsigned int flags, 107 struct blk_mq_ctx *ctx) 108 { 109 enum hctx_type type = HCTX_TYPE_DEFAULT; 110 111 /* 112 * The caller ensure that if REQ_HIPRI, poll must be enabled. 113 */ 114 if (flags & REQ_HIPRI) 115 type = HCTX_TYPE_POLL; 116 else if ((flags & REQ_OP_MASK) == REQ_OP_READ) 117 type = HCTX_TYPE_READ; 118 119 return ctx->hctxs[type]; 120 } 121 122 /* 123 * sysfs helpers 124 */ 125 extern void blk_mq_sysfs_init(struct request_queue *q); 126 extern void blk_mq_sysfs_deinit(struct request_queue *q); 127 extern int __blk_mq_register_dev(struct device *dev, struct request_queue *q); 128 extern int blk_mq_sysfs_register(struct request_queue *q); 129 extern void blk_mq_sysfs_unregister(struct request_queue *q); 130 extern void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx); 131 132 void blk_mq_release(struct request_queue *q); 133 134 static inline struct blk_mq_ctx *__blk_mq_get_ctx(struct request_queue *q, 135 unsigned int cpu) 136 { 137 return per_cpu_ptr(q->queue_ctx, cpu); 138 } 139 140 /* 141 * This assumes per-cpu software queueing queues. They could be per-node 142 * as well, for instance. For now this is hardcoded as-is. Note that we don't 143 * care about preemption, since we know the ctx's are persistent. This does 144 * mean that we can't rely on ctx always matching the currently running CPU. 145 */ 146 static inline struct blk_mq_ctx *blk_mq_get_ctx(struct request_queue *q) 147 { 148 return __blk_mq_get_ctx(q, raw_smp_processor_id()); 149 } 150 151 struct blk_mq_alloc_data { 152 /* input parameter */ 153 struct request_queue *q; 154 blk_mq_req_flags_t flags; 155 unsigned int shallow_depth; 156 unsigned int cmd_flags; 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_sbitmap_shared(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->q->elevator) 171 return data->hctx->sched_tags; 172 173 return data->hctx->tags; 174 } 175 176 static inline bool blk_mq_hctx_stopped(struct blk_mq_hw_ctx *hctx) 177 { 178 return test_bit(BLK_MQ_S_STOPPED, &hctx->state); 179 } 180 181 static inline bool blk_mq_hw_queue_mapped(struct blk_mq_hw_ctx *hctx) 182 { 183 return hctx->nr_ctx && hctx->tags; 184 } 185 186 unsigned int blk_mq_in_flight(struct request_queue *q, 187 struct block_device *part); 188 void blk_mq_in_flight_rw(struct request_queue *q, struct block_device *part, 189 unsigned int inflight[2]); 190 191 static inline void blk_mq_put_dispatch_budget(struct request_queue *q, 192 int budget_token) 193 { 194 if (q->mq_ops->put_budget) 195 q->mq_ops->put_budget(q, budget_token); 196 } 197 198 static inline int blk_mq_get_dispatch_budget(struct request_queue *q) 199 { 200 if (q->mq_ops->get_budget) 201 return q->mq_ops->get_budget(q); 202 return 0; 203 } 204 205 static inline void blk_mq_set_rq_budget_token(struct request *rq, int token) 206 { 207 if (token < 0) 208 return; 209 210 if (rq->q->mq_ops->set_rq_budget_token) 211 rq->q->mq_ops->set_rq_budget_token(rq, token); 212 } 213 214 static inline int blk_mq_get_rq_budget_token(struct request *rq) 215 { 216 if (rq->q->mq_ops->get_rq_budget_token) 217 return rq->q->mq_ops->get_rq_budget_token(rq); 218 return -1; 219 } 220 221 static inline void __blk_mq_inc_active_requests(struct blk_mq_hw_ctx *hctx) 222 { 223 if (blk_mq_is_sbitmap_shared(hctx->flags)) 224 atomic_inc(&hctx->queue->nr_active_requests_shared_sbitmap); 225 else 226 atomic_inc(&hctx->nr_active); 227 } 228 229 static inline void __blk_mq_dec_active_requests(struct blk_mq_hw_ctx *hctx) 230 { 231 if (blk_mq_is_sbitmap_shared(hctx->flags)) 232 atomic_dec(&hctx->queue->nr_active_requests_shared_sbitmap); 233 else 234 atomic_dec(&hctx->nr_active); 235 } 236 237 static inline int __blk_mq_active_requests(struct blk_mq_hw_ctx *hctx) 238 { 239 if (blk_mq_is_sbitmap_shared(hctx->flags)) 240 return atomic_read(&hctx->queue->nr_active_requests_shared_sbitmap); 241 return atomic_read(&hctx->nr_active); 242 } 243 static inline void __blk_mq_put_driver_tag(struct blk_mq_hw_ctx *hctx, 244 struct request *rq) 245 { 246 blk_mq_put_tag(hctx->tags, rq->mq_ctx, rq->tag); 247 rq->tag = BLK_MQ_NO_TAG; 248 249 if (rq->rq_flags & RQF_MQ_INFLIGHT) { 250 rq->rq_flags &= ~RQF_MQ_INFLIGHT; 251 __blk_mq_dec_active_requests(hctx); 252 } 253 } 254 255 static inline void blk_mq_put_driver_tag(struct request *rq) 256 { 257 if (rq->tag == BLK_MQ_NO_TAG || rq->internal_tag == BLK_MQ_NO_TAG) 258 return; 259 260 __blk_mq_put_driver_tag(rq->mq_hctx, rq); 261 } 262 263 static inline void blk_mq_clear_mq_map(struct blk_mq_queue_map *qmap) 264 { 265 int cpu; 266 267 for_each_possible_cpu(cpu) 268 qmap->mq_map[cpu] = 0; 269 } 270 271 /* 272 * blk_mq_plug() - Get caller context plug 273 * @q: request queue 274 * @bio : the bio being submitted by the caller context 275 * 276 * Plugging, by design, may delay the insertion of BIOs into the elevator in 277 * order to increase BIO merging opportunities. This however can cause BIO 278 * insertion order to change from the order in which submit_bio() is being 279 * executed in the case of multiple contexts concurrently issuing BIOs to a 280 * device, even if these context are synchronized to tightly control BIO issuing 281 * order. While this is not a problem with regular block devices, this ordering 282 * change can cause write BIO failures with zoned block devices as these 283 * require sequential write patterns to zones. Prevent this from happening by 284 * ignoring the plug state of a BIO issuing context if the target request queue 285 * is for a zoned block device and the BIO to plug is a write operation. 286 * 287 * Return current->plug if the bio can be plugged and NULL otherwise 288 */ 289 static inline struct blk_plug *blk_mq_plug(struct request_queue *q, 290 struct bio *bio) 291 { 292 /* 293 * For regular block devices or read operations, use the context plug 294 * which may be NULL if blk_start_plug() was not executed. 295 */ 296 if (!blk_queue_is_zoned(q) || !op_is_write(bio_op(bio))) 297 return current->plug; 298 299 /* Zoned block device write operation case: do not plug the BIO */ 300 return NULL; 301 } 302 303 /* 304 * For shared tag users, we track the number of currently active users 305 * and attempt to provide a fair share of the tag depth for each of them. 306 */ 307 static inline bool hctx_may_queue(struct blk_mq_hw_ctx *hctx, 308 struct sbitmap_queue *bt) 309 { 310 unsigned int depth, users; 311 312 if (!hctx || !(hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED)) 313 return true; 314 315 /* 316 * Don't try dividing an ant 317 */ 318 if (bt->sb.depth == 1) 319 return true; 320 321 if (blk_mq_is_sbitmap_shared(hctx->flags)) { 322 struct request_queue *q = hctx->queue; 323 struct blk_mq_tag_set *set = q->tag_set; 324 325 if (!test_bit(QUEUE_FLAG_HCTX_ACTIVE, &q->queue_flags)) 326 return true; 327 users = atomic_read(&set->active_queues_shared_sbitmap); 328 } else { 329 if (!test_bit(BLK_MQ_S_TAG_ACTIVE, &hctx->state)) 330 return true; 331 users = atomic_read(&hctx->tags->active_queues); 332 } 333 334 if (!users) 335 return true; 336 337 /* 338 * Allow at least some tags 339 */ 340 depth = max((bt->sb.depth + users - 1) / users, 4U); 341 return __blk_mq_active_requests(hctx) < depth; 342 } 343 344 345 #endif 346