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 8struct blk_mq_tag_set; 9 10struct 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 */ 18struct 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 40void blk_mq_exit_queue(struct request_queue *q); 41int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr); 42void blk_mq_wake_waiters(struct request_queue *q); 43bool blk_mq_dispatch_rq_list(struct blk_mq_hw_ctx *hctx, struct list_head *, 44 unsigned int); 45void blk_mq_add_to_requeue_list(struct request *rq, bool at_head, 46 bool kick_requeue_list); 47void blk_mq_flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, struct list_head *list); 48struct request *blk_mq_dequeue_from_ctx(struct blk_mq_hw_ctx *hctx, 49 struct blk_mq_ctx *start); 50void blk_mq_put_rq_ref(struct request *rq); 51 52/* 53 * Internal helpers for allocating/freeing the request map 54 */ 55void blk_mq_free_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags, 56 unsigned int hctx_idx); 57void blk_mq_free_rq_map(struct blk_mq_tags *tags, unsigned int flags); 58struct 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); 63int 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 */ 69void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq, 70 bool at_head); 71void blk_mq_request_bypass_insert(struct request *rq, bool at_head, 72 bool run_queue); 73void 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 */ 77blk_status_t blk_mq_request_issue_directly(struct request *rq, bool last); 78void blk_mq_try_issue_list_directly(struct blk_mq_hw_ctx *hctx, 79 struct list_head *list); 80 81/* 82 * CPU -> queue mappings 83 */ 84extern 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 */ 92static 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 * @cpu: cpu ctx 104 */ 105static 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 */ 125extern void blk_mq_sysfs_init(struct request_queue *q); 126extern void blk_mq_sysfs_deinit(struct request_queue *q); 127extern int __blk_mq_register_dev(struct device *dev, struct request_queue *q); 128extern int blk_mq_sysfs_register(struct request_queue *q); 129extern void blk_mq_sysfs_unregister(struct request_queue *q); 130extern void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx); 131 132void blk_mq_cancel_work_sync(struct request_queue *q); 133void blk_mq_release(struct request_queue *q); 134 135static inline struct blk_mq_ctx *__blk_mq_get_ctx(struct request_queue *q, 136 unsigned int cpu) 137{ 138 return per_cpu_ptr(q->queue_ctx, cpu); 139} 140 141/* 142 * This assumes per-cpu software queueing queues. They could be per-node 143 * as well, for instance. For now this is hardcoded as-is. Note that we don't 144 * care about preemption, since we know the ctx's are persistent. This does 145 * mean that we can't rely on ctx always matching the currently running CPU. 146 */ 147static inline struct blk_mq_ctx *blk_mq_get_ctx(struct request_queue *q) 148{ 149 return __blk_mq_get_ctx(q, raw_smp_processor_id()); 150} 151 152struct blk_mq_alloc_data { 153 /* input parameter */ 154 struct request_queue *q; 155 blk_mq_req_flags_t flags; 156 unsigned int shallow_depth; 157 unsigned int cmd_flags; 158 159 /* input & output parameter */ 160 struct blk_mq_ctx *ctx; 161 struct blk_mq_hw_ctx *hctx; 162}; 163 164static inline bool blk_mq_is_sbitmap_shared(unsigned int flags) 165{ 166 return flags & BLK_MQ_F_TAG_HCTX_SHARED; 167} 168 169static inline struct blk_mq_tags *blk_mq_tags_from_data(struct blk_mq_alloc_data *data) 170{ 171 if (data->q->elevator) 172 return data->hctx->sched_tags; 173 174 return data->hctx->tags; 175} 176 177static inline bool blk_mq_hctx_stopped(struct blk_mq_hw_ctx *hctx) 178{ 179 return test_bit(BLK_MQ_S_STOPPED, &hctx->state); 180} 181 182static inline bool blk_mq_hw_queue_mapped(struct blk_mq_hw_ctx *hctx) 183{ 184 return hctx->nr_ctx && hctx->tags; 185} 186 187unsigned int blk_mq_in_flight(struct request_queue *q, struct hd_struct *part); 188void blk_mq_in_flight_rw(struct request_queue *q, struct hd_struct *part, 189 unsigned int inflight[2]); 190 191static inline void blk_mq_put_dispatch_budget(struct request_queue *q) 192{ 193 if (q->mq_ops->put_budget) 194 q->mq_ops->put_budget(q); 195} 196 197static inline bool 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 true; 202} 203 204static inline void __blk_mq_inc_active_requests(struct blk_mq_hw_ctx *hctx) 205{ 206 if (blk_mq_is_sbitmap_shared(hctx->flags)) 207 atomic_inc(&hctx->queue->nr_active_requests_shared_sbitmap); 208 else 209 atomic_inc(&hctx->nr_active); 210} 211 212static inline void __blk_mq_dec_active_requests(struct blk_mq_hw_ctx *hctx) 213{ 214 if (blk_mq_is_sbitmap_shared(hctx->flags)) 215 atomic_dec(&hctx->queue->nr_active_requests_shared_sbitmap); 216 else 217 atomic_dec(&hctx->nr_active); 218} 219 220static inline int __blk_mq_active_requests(struct blk_mq_hw_ctx *hctx) 221{ 222 if (blk_mq_is_sbitmap_shared(hctx->flags)) 223 return atomic_read(&hctx->queue->nr_active_requests_shared_sbitmap); 224 return atomic_read(&hctx->nr_active); 225} 226static inline void __blk_mq_put_driver_tag(struct blk_mq_hw_ctx *hctx, 227 struct request *rq) 228{ 229 blk_mq_put_tag(hctx->tags, rq->mq_ctx, rq->tag); 230 rq->tag = BLK_MQ_NO_TAG; 231 232 if (rq->rq_flags & RQF_MQ_INFLIGHT) { 233 rq->rq_flags &= ~RQF_MQ_INFLIGHT; 234 __blk_mq_dec_active_requests(hctx); 235 } 236} 237 238static inline void blk_mq_put_driver_tag(struct request *rq) 239{ 240 if (rq->tag == BLK_MQ_NO_TAG || rq->internal_tag == BLK_MQ_NO_TAG) 241 return; 242 243 __blk_mq_put_driver_tag(rq->mq_hctx, rq); 244} 245 246static inline void blk_mq_clear_mq_map(struct blk_mq_queue_map *qmap) 247{ 248 int cpu; 249 250 for_each_possible_cpu(cpu) 251 qmap->mq_map[cpu] = 0; 252} 253 254/* 255 * blk_mq_plug() - Get caller context plug 256 * @q: request queue 257 * @bio : the bio being submitted by the caller context 258 * 259 * Plugging, by design, may delay the insertion of BIOs into the elevator in 260 * order to increase BIO merging opportunities. This however can cause BIO 261 * insertion order to change from the order in which submit_bio() is being 262 * executed in the case of multiple contexts concurrently issuing BIOs to a 263 * device, even if these context are synchronized to tightly control BIO issuing 264 * order. While this is not a problem with regular block devices, this ordering 265 * change can cause write BIO failures with zoned block devices as these 266 * require sequential write patterns to zones. Prevent this from happening by 267 * ignoring the plug state of a BIO issuing context if the target request queue 268 * is for a zoned block device and the BIO to plug is a write operation. 269 * 270 * Return current->plug if the bio can be plugged and NULL otherwise 271 */ 272static inline struct blk_plug *blk_mq_plug(struct request_queue *q, 273 struct bio *bio) 274{ 275 /* 276 * For regular block devices or read operations, use the context plug 277 * which may be NULL if blk_start_plug() was not executed. 278 */ 279 if (!blk_queue_is_zoned(q) || !op_is_write(bio_op(bio))) 280 return current->plug; 281 282 /* Zoned block device write operation case: do not plug the BIO */ 283 return NULL; 284} 285 286/* Free all requests on the list */ 287static inline void blk_mq_free_requests(struct list_head *list) 288{ 289 while (!list_empty(list)) { 290 struct request *rq = list_entry_rq(list->next); 291 292 list_del_init(&rq->queuelist); 293 blk_mq_free_request(rq); 294 } 295} 296 297/* 298 * For shared tag users, we track the number of currently active users 299 * and attempt to provide a fair share of the tag depth for each of them. 300 */ 301static inline bool hctx_may_queue(struct blk_mq_hw_ctx *hctx, 302 struct sbitmap_queue *bt) 303{ 304 unsigned int depth, users; 305 306 if (!hctx || !(hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED)) 307 return true; 308 309 /* 310 * Don't try dividing an ant 311 */ 312 if (bt->sb.depth == 1) 313 return true; 314 315 if (blk_mq_is_sbitmap_shared(hctx->flags)) { 316 struct request_queue *q = hctx->queue; 317 struct blk_mq_tag_set *set = q->tag_set; 318 319 if (!test_bit(QUEUE_FLAG_HCTX_ACTIVE, &q->queue_flags)) 320 return true; 321 users = atomic_read(&set->active_queues_shared_sbitmap); 322 } else { 323 if (!test_bit(BLK_MQ_S_TAG_ACTIVE, &hctx->state)) 324 return true; 325 users = atomic_read(&hctx->tags->active_queues); 326 } 327 328 if (!users) 329 return true; 330 331 /* 332 * Allow at least some tags 333 */ 334 depth = max((bt->sb.depth + users - 1) / users, 4U); 335 return __blk_mq_active_requests(hctx) < depth; 336} 337 338 339#endif 340