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 51 /* 52 * Internal helpers for allocating/freeing the request map 53 */ 54 void blk_mq_free_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags, 55 unsigned int hctx_idx); 56 void blk_mq_free_rq_map(struct blk_mq_tags *tags, unsigned int flags); 57 struct blk_mq_tags *blk_mq_alloc_rq_map(struct blk_mq_tag_set *set, 58 unsigned int hctx_idx, 59 unsigned int nr_tags, 60 unsigned int reserved_tags, 61 unsigned int flags); 62 int blk_mq_alloc_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags, 63 unsigned int hctx_idx, unsigned int depth); 64 65 /* 66 * Internal helpers for request insertion into sw queues 67 */ 68 void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq, 69 bool at_head); 70 void blk_mq_request_bypass_insert(struct request *rq, bool at_head, 71 bool run_queue); 72 void blk_mq_insert_requests(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx, 73 struct list_head *list); 74 75 /* Used by blk_insert_cloned_request() to issue request directly */ 76 blk_status_t blk_mq_request_issue_directly(struct request *rq, bool last); 77 void blk_mq_try_issue_list_directly(struct blk_mq_hw_ctx *hctx, 78 struct list_head *list); 79 80 /* 81 * CPU -> queue mappings 82 */ 83 extern int blk_mq_hw_queue_to_node(struct blk_mq_queue_map *qmap, unsigned int); 84 85 /* 86 * blk_mq_map_queue_type() - map (hctx_type,cpu) to hardware queue 87 * @q: request queue 88 * @type: the hctx type index 89 * @cpu: CPU 90 */ 91 static inline struct blk_mq_hw_ctx *blk_mq_map_queue_type(struct request_queue *q, 92 enum hctx_type type, 93 unsigned int cpu) 94 { 95 return q->queue_hw_ctx[q->tag_set->map[type].mq_map[cpu]]; 96 } 97 98 /* 99 * blk_mq_map_queue() - map (cmd_flags,type) to hardware queue 100 * @q: request queue 101 * @flags: request command flags 102 * @ctx: software queue cpu ctx 103 */ 104 static inline struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q, 105 unsigned int flags, 106 struct blk_mq_ctx *ctx) 107 { 108 enum hctx_type type = HCTX_TYPE_DEFAULT; 109 110 /* 111 * The caller ensure that if REQ_HIPRI, poll must be enabled. 112 */ 113 if (flags & REQ_HIPRI) 114 type = HCTX_TYPE_POLL; 115 else if ((flags & REQ_OP_MASK) == REQ_OP_READ) 116 type = HCTX_TYPE_READ; 117 118 return ctx->hctxs[type]; 119 } 120 121 /* 122 * sysfs helpers 123 */ 124 extern void blk_mq_sysfs_init(struct request_queue *q); 125 extern void blk_mq_sysfs_deinit(struct request_queue *q); 126 extern int __blk_mq_register_dev(struct device *dev, struct request_queue *q); 127 extern int blk_mq_sysfs_register(struct request_queue *q); 128 extern void blk_mq_sysfs_unregister(struct request_queue *q); 129 extern void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx); 130 131 void blk_mq_release(struct request_queue *q); 132 133 static inline struct blk_mq_ctx *__blk_mq_get_ctx(struct request_queue *q, 134 unsigned int cpu) 135 { 136 return per_cpu_ptr(q->queue_ctx, cpu); 137 } 138 139 /* 140 * This assumes per-cpu software queueing queues. They could be per-node 141 * as well, for instance. For now this is hardcoded as-is. Note that we don't 142 * care about preemption, since we know the ctx's are persistent. This does 143 * mean that we can't rely on ctx always matching the currently running CPU. 144 */ 145 static inline struct blk_mq_ctx *blk_mq_get_ctx(struct request_queue *q) 146 { 147 return __blk_mq_get_ctx(q, raw_smp_processor_id()); 148 } 149 150 struct blk_mq_alloc_data { 151 /* input parameter */ 152 struct request_queue *q; 153 blk_mq_req_flags_t flags; 154 unsigned int shallow_depth; 155 unsigned int cmd_flags; 156 157 /* input & output parameter */ 158 struct blk_mq_ctx *ctx; 159 struct blk_mq_hw_ctx *hctx; 160 }; 161 162 static inline bool blk_mq_is_sbitmap_shared(unsigned int flags) 163 { 164 return flags & BLK_MQ_F_TAG_HCTX_SHARED; 165 } 166 167 static inline struct blk_mq_tags *blk_mq_tags_from_data(struct blk_mq_alloc_data *data) 168 { 169 if (data->q->elevator) 170 return data->hctx->sched_tags; 171 172 return data->hctx->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 { 192 if (q->mq_ops->put_budget) 193 q->mq_ops->put_budget(q); 194 } 195 196 static inline bool blk_mq_get_dispatch_budget(struct request_queue *q) 197 { 198 if (q->mq_ops->get_budget) 199 return q->mq_ops->get_budget(q); 200 return true; 201 } 202 203 static inline void __blk_mq_inc_active_requests(struct blk_mq_hw_ctx *hctx) 204 { 205 if (blk_mq_is_sbitmap_shared(hctx->flags)) 206 atomic_inc(&hctx->queue->nr_active_requests_shared_sbitmap); 207 else 208 atomic_inc(&hctx->nr_active); 209 } 210 211 static inline void __blk_mq_dec_active_requests(struct blk_mq_hw_ctx *hctx) 212 { 213 if (blk_mq_is_sbitmap_shared(hctx->flags)) 214 atomic_dec(&hctx->queue->nr_active_requests_shared_sbitmap); 215 else 216 atomic_dec(&hctx->nr_active); 217 } 218 219 static inline int __blk_mq_active_requests(struct blk_mq_hw_ctx *hctx) 220 { 221 if (blk_mq_is_sbitmap_shared(hctx->flags)) 222 return atomic_read(&hctx->queue->nr_active_requests_shared_sbitmap); 223 return atomic_read(&hctx->nr_active); 224 } 225 static inline void __blk_mq_put_driver_tag(struct blk_mq_hw_ctx *hctx, 226 struct request *rq) 227 { 228 blk_mq_put_tag(hctx->tags, rq->mq_ctx, rq->tag); 229 rq->tag = BLK_MQ_NO_TAG; 230 231 if (rq->rq_flags & RQF_MQ_INFLIGHT) { 232 rq->rq_flags &= ~RQF_MQ_INFLIGHT; 233 __blk_mq_dec_active_requests(hctx); 234 } 235 } 236 237 static inline void blk_mq_put_driver_tag(struct request *rq) 238 { 239 if (rq->tag == BLK_MQ_NO_TAG || rq->internal_tag == BLK_MQ_NO_TAG) 240 return; 241 242 __blk_mq_put_driver_tag(rq->mq_hctx, rq); 243 } 244 245 static inline void blk_mq_clear_mq_map(struct blk_mq_queue_map *qmap) 246 { 247 int cpu; 248 249 for_each_possible_cpu(cpu) 250 qmap->mq_map[cpu] = 0; 251 } 252 253 /* 254 * blk_mq_plug() - Get caller context plug 255 * @q: request queue 256 * @bio : the bio being submitted by the caller context 257 * 258 * Plugging, by design, may delay the insertion of BIOs into the elevator in 259 * order to increase BIO merging opportunities. This however can cause BIO 260 * insertion order to change from the order in which submit_bio() is being 261 * executed in the case of multiple contexts concurrently issuing BIOs to a 262 * device, even if these context are synchronized to tightly control BIO issuing 263 * order. While this is not a problem with regular block devices, this ordering 264 * change can cause write BIO failures with zoned block devices as these 265 * require sequential write patterns to zones. Prevent this from happening by 266 * ignoring the plug state of a BIO issuing context if the target request queue 267 * is for a zoned block device and the BIO to plug is a write operation. 268 * 269 * Return current->plug if the bio can be plugged and NULL otherwise 270 */ 271 static inline struct blk_plug *blk_mq_plug(struct request_queue *q, 272 struct bio *bio) 273 { 274 /* 275 * For regular block devices or read operations, use the context plug 276 * which may be NULL if blk_start_plug() was not executed. 277 */ 278 if (!blk_queue_is_zoned(q) || !op_is_write(bio_op(bio))) 279 return current->plug; 280 281 /* Zoned block device write operation case: do not plug the BIO */ 282 return NULL; 283 } 284 285 /* 286 * For shared tag users, we track the number of currently active users 287 * and attempt to provide a fair share of the tag depth for each of them. 288 */ 289 static inline bool hctx_may_queue(struct blk_mq_hw_ctx *hctx, 290 struct sbitmap_queue *bt) 291 { 292 unsigned int depth, users; 293 294 if (!hctx || !(hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED)) 295 return true; 296 297 /* 298 * Don't try dividing an ant 299 */ 300 if (bt->sb.depth == 1) 301 return true; 302 303 if (blk_mq_is_sbitmap_shared(hctx->flags)) { 304 struct request_queue *q = hctx->queue; 305 struct blk_mq_tag_set *set = q->tag_set; 306 307 if (!test_bit(BLK_MQ_S_TAG_ACTIVE, &q->queue_flags)) 308 return true; 309 users = atomic_read(&set->active_queues_shared_sbitmap); 310 } else { 311 if (!test_bit(BLK_MQ_S_TAG_ACTIVE, &hctx->state)) 312 return true; 313 users = atomic_read(&hctx->tags->active_queues); 314 } 315 316 if (!users) 317 return true; 318 319 /* 320 * Allow at least some tags 321 */ 322 depth = max((bt->sb.depth + users - 1) / users, 4U); 323 return __blk_mq_active_requests(hctx) < depth; 324 } 325 326 327 #endif 328