1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef BLK_MQ_H 3 #define BLK_MQ_H 4 5 #include <linux/blkdev.h> 6 #include <linux/sbitmap.h> 7 #include <linux/srcu.h> 8 9 struct blk_mq_tags; 10 struct blk_flush_queue; 11 12 /** 13 * struct blk_mq_hw_ctx - State for a hardware queue facing the hardware block device 14 */ 15 struct blk_mq_hw_ctx { 16 struct { 17 spinlock_t lock; 18 struct list_head dispatch; 19 unsigned long state; /* BLK_MQ_S_* flags */ 20 } ____cacheline_aligned_in_smp; 21 22 struct delayed_work run_work; 23 cpumask_var_t cpumask; 24 int next_cpu; 25 int next_cpu_batch; 26 27 unsigned long flags; /* BLK_MQ_F_* flags */ 28 29 void *sched_data; 30 struct request_queue *queue; 31 struct blk_flush_queue *fq; 32 33 void *driver_data; 34 35 struct sbitmap ctx_map; 36 37 struct blk_mq_ctx *dispatch_from; 38 unsigned int dispatch_busy; 39 40 unsigned short type; 41 unsigned short nr_ctx; 42 struct blk_mq_ctx **ctxs; 43 44 spinlock_t dispatch_wait_lock; 45 wait_queue_entry_t dispatch_wait; 46 atomic_t wait_index; 47 48 struct blk_mq_tags *tags; 49 struct blk_mq_tags *sched_tags; 50 51 unsigned long queued; 52 unsigned long run; 53 #define BLK_MQ_MAX_DISPATCH_ORDER 7 54 unsigned long dispatched[BLK_MQ_MAX_DISPATCH_ORDER]; 55 56 unsigned int numa_node; 57 unsigned int queue_num; 58 59 atomic_t nr_active; 60 unsigned int nr_expired; 61 62 struct hlist_node cpuhp_dead; 63 struct kobject kobj; 64 65 unsigned long poll_considered; 66 unsigned long poll_invoked; 67 unsigned long poll_success; 68 69 #ifdef CONFIG_BLK_DEBUG_FS 70 struct dentry *debugfs_dir; 71 struct dentry *sched_debugfs_dir; 72 #endif 73 74 /* Must be the last member - see also blk_mq_hw_ctx_size(). */ 75 struct srcu_struct srcu[0]; 76 }; 77 78 struct blk_mq_queue_map { 79 unsigned int *mq_map; 80 unsigned int nr_queues; 81 unsigned int queue_offset; 82 }; 83 84 enum hctx_type { 85 HCTX_TYPE_DEFAULT, /* all I/O not otherwise accounted for */ 86 HCTX_TYPE_READ, /* just for READ I/O */ 87 HCTX_TYPE_POLL, /* polled I/O of any kind */ 88 89 HCTX_MAX_TYPES, 90 }; 91 92 struct blk_mq_tag_set { 93 /* 94 * map[] holds ctx -> hctx mappings, one map exists for each type 95 * that the driver wishes to support. There are no restrictions 96 * on maps being of the same size, and it's perfectly legal to 97 * share maps between types. 98 */ 99 struct blk_mq_queue_map map[HCTX_MAX_TYPES]; 100 unsigned int nr_maps; /* nr entries in map[] */ 101 const struct blk_mq_ops *ops; 102 unsigned int nr_hw_queues; /* nr hw queues across maps */ 103 unsigned int queue_depth; /* max hw supported */ 104 unsigned int reserved_tags; 105 unsigned int cmd_size; /* per-request extra data */ 106 int numa_node; 107 unsigned int timeout; 108 unsigned int flags; /* BLK_MQ_F_* */ 109 void *driver_data; 110 111 struct blk_mq_tags **tags; 112 113 struct mutex tag_list_lock; 114 struct list_head tag_list; 115 }; 116 117 struct blk_mq_queue_data { 118 struct request *rq; 119 bool last; 120 }; 121 122 typedef blk_status_t (queue_rq_fn)(struct blk_mq_hw_ctx *, 123 const struct blk_mq_queue_data *); 124 typedef void (commit_rqs_fn)(struct blk_mq_hw_ctx *); 125 typedef bool (get_budget_fn)(struct blk_mq_hw_ctx *); 126 typedef void (put_budget_fn)(struct blk_mq_hw_ctx *); 127 typedef enum blk_eh_timer_return (timeout_fn)(struct request *, bool); 128 typedef int (init_hctx_fn)(struct blk_mq_hw_ctx *, void *, unsigned int); 129 typedef void (exit_hctx_fn)(struct blk_mq_hw_ctx *, unsigned int); 130 typedef int (init_request_fn)(struct blk_mq_tag_set *set, struct request *, 131 unsigned int, unsigned int); 132 typedef void (exit_request_fn)(struct blk_mq_tag_set *set, struct request *, 133 unsigned int); 134 135 typedef bool (busy_iter_fn)(struct blk_mq_hw_ctx *, struct request *, void *, 136 bool); 137 typedef bool (busy_tag_iter_fn)(struct request *, void *, bool); 138 typedef int (poll_fn)(struct blk_mq_hw_ctx *); 139 typedef int (map_queues_fn)(struct blk_mq_tag_set *set); 140 typedef bool (busy_fn)(struct request_queue *); 141 typedef void (complete_fn)(struct request *); 142 143 144 struct blk_mq_ops { 145 /* 146 * Queue request 147 */ 148 queue_rq_fn *queue_rq; 149 150 /* 151 * If a driver uses bd->last to judge when to submit requests to 152 * hardware, it must define this function. In case of errors that 153 * make us stop issuing further requests, this hook serves the 154 * purpose of kicking the hardware (which the last request otherwise 155 * would have done). 156 */ 157 commit_rqs_fn *commit_rqs; 158 159 /* 160 * Reserve budget before queue request, once .queue_rq is 161 * run, it is driver's responsibility to release the 162 * reserved budget. Also we have to handle failure case 163 * of .get_budget for avoiding I/O deadlock. 164 */ 165 get_budget_fn *get_budget; 166 put_budget_fn *put_budget; 167 168 /* 169 * Called on request timeout 170 */ 171 timeout_fn *timeout; 172 173 /* 174 * Called to poll for completion of a specific tag. 175 */ 176 poll_fn *poll; 177 178 complete_fn *complete; 179 180 /* 181 * Called when the block layer side of a hardware queue has been 182 * set up, allowing the driver to allocate/init matching structures. 183 * Ditto for exit/teardown. 184 */ 185 init_hctx_fn *init_hctx; 186 exit_hctx_fn *exit_hctx; 187 188 /* 189 * Called for every command allocated by the block layer to allow 190 * the driver to set up driver specific data. 191 * 192 * Tag greater than or equal to queue_depth is for setting up 193 * flush request. 194 * 195 * Ditto for exit/teardown. 196 */ 197 init_request_fn *init_request; 198 exit_request_fn *exit_request; 199 /* Called from inside blk_get_request() */ 200 void (*initialize_rq_fn)(struct request *rq); 201 202 /* 203 * If set, returns whether or not this queue currently is busy 204 */ 205 busy_fn *busy; 206 207 map_queues_fn *map_queues; 208 209 #ifdef CONFIG_BLK_DEBUG_FS 210 /* 211 * Used by the debugfs implementation to show driver-specific 212 * information about a request. 213 */ 214 void (*show_rq)(struct seq_file *m, struct request *rq); 215 #endif 216 }; 217 218 enum { 219 BLK_MQ_F_SHOULD_MERGE = 1 << 0, 220 BLK_MQ_F_TAG_SHARED = 1 << 1, 221 BLK_MQ_F_SG_MERGE = 1 << 2, 222 BLK_MQ_F_BLOCKING = 1 << 5, 223 BLK_MQ_F_NO_SCHED = 1 << 6, 224 BLK_MQ_F_ALLOC_POLICY_START_BIT = 8, 225 BLK_MQ_F_ALLOC_POLICY_BITS = 1, 226 227 BLK_MQ_S_STOPPED = 0, 228 BLK_MQ_S_TAG_ACTIVE = 1, 229 BLK_MQ_S_SCHED_RESTART = 2, 230 231 BLK_MQ_MAX_DEPTH = 10240, 232 233 BLK_MQ_CPU_WORK_BATCH = 8, 234 }; 235 #define BLK_MQ_FLAG_TO_ALLOC_POLICY(flags) \ 236 ((flags >> BLK_MQ_F_ALLOC_POLICY_START_BIT) & \ 237 ((1 << BLK_MQ_F_ALLOC_POLICY_BITS) - 1)) 238 #define BLK_ALLOC_POLICY_TO_MQ_FLAG(policy) \ 239 ((policy & ((1 << BLK_MQ_F_ALLOC_POLICY_BITS) - 1)) \ 240 << BLK_MQ_F_ALLOC_POLICY_START_BIT) 241 242 struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *); 243 struct request_queue *blk_mq_init_allocated_queue(struct blk_mq_tag_set *set, 244 struct request_queue *q); 245 struct request_queue *blk_mq_init_sq_queue(struct blk_mq_tag_set *set, 246 const struct blk_mq_ops *ops, 247 unsigned int queue_depth, 248 unsigned int set_flags); 249 int blk_mq_register_dev(struct device *, struct request_queue *); 250 void blk_mq_unregister_dev(struct device *, struct request_queue *); 251 252 int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set); 253 void blk_mq_free_tag_set(struct blk_mq_tag_set *set); 254 255 void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule); 256 257 void blk_mq_free_request(struct request *rq); 258 bool blk_mq_can_queue(struct blk_mq_hw_ctx *); 259 260 bool blk_mq_queue_inflight(struct request_queue *q); 261 262 enum { 263 /* return when out of requests */ 264 BLK_MQ_REQ_NOWAIT = (__force blk_mq_req_flags_t)(1 << 0), 265 /* allocate from reserved pool */ 266 BLK_MQ_REQ_RESERVED = (__force blk_mq_req_flags_t)(1 << 1), 267 /* allocate internal/sched tag */ 268 BLK_MQ_REQ_INTERNAL = (__force blk_mq_req_flags_t)(1 << 2), 269 /* set RQF_PREEMPT */ 270 BLK_MQ_REQ_PREEMPT = (__force blk_mq_req_flags_t)(1 << 3), 271 }; 272 273 struct request *blk_mq_alloc_request(struct request_queue *q, unsigned int op, 274 blk_mq_req_flags_t flags); 275 struct request *blk_mq_alloc_request_hctx(struct request_queue *q, 276 unsigned int op, blk_mq_req_flags_t flags, 277 unsigned int hctx_idx); 278 struct request *blk_mq_tag_to_rq(struct blk_mq_tags *tags, unsigned int tag); 279 280 enum { 281 BLK_MQ_UNIQUE_TAG_BITS = 16, 282 BLK_MQ_UNIQUE_TAG_MASK = (1 << BLK_MQ_UNIQUE_TAG_BITS) - 1, 283 }; 284 285 u32 blk_mq_unique_tag(struct request *rq); 286 287 static inline u16 blk_mq_unique_tag_to_hwq(u32 unique_tag) 288 { 289 return unique_tag >> BLK_MQ_UNIQUE_TAG_BITS; 290 } 291 292 static inline u16 blk_mq_unique_tag_to_tag(u32 unique_tag) 293 { 294 return unique_tag & BLK_MQ_UNIQUE_TAG_MASK; 295 } 296 297 298 int blk_mq_request_started(struct request *rq); 299 void blk_mq_start_request(struct request *rq); 300 void blk_mq_end_request(struct request *rq, blk_status_t error); 301 void __blk_mq_end_request(struct request *rq, blk_status_t error); 302 303 void blk_mq_requeue_request(struct request *rq, bool kick_requeue_list); 304 void blk_mq_add_to_requeue_list(struct request *rq, bool at_head, 305 bool kick_requeue_list); 306 void blk_mq_kick_requeue_list(struct request_queue *q); 307 void blk_mq_delay_kick_requeue_list(struct request_queue *q, unsigned long msecs); 308 bool blk_mq_complete_request(struct request *rq); 309 bool blk_mq_bio_list_merge(struct request_queue *q, struct list_head *list, 310 struct bio *bio); 311 bool blk_mq_queue_stopped(struct request_queue *q); 312 void blk_mq_stop_hw_queue(struct blk_mq_hw_ctx *hctx); 313 void blk_mq_start_hw_queue(struct blk_mq_hw_ctx *hctx); 314 void blk_mq_stop_hw_queues(struct request_queue *q); 315 void blk_mq_start_hw_queues(struct request_queue *q); 316 void blk_mq_start_stopped_hw_queue(struct blk_mq_hw_ctx *hctx, bool async); 317 void blk_mq_start_stopped_hw_queues(struct request_queue *q, bool async); 318 void blk_mq_quiesce_queue(struct request_queue *q); 319 void blk_mq_unquiesce_queue(struct request_queue *q); 320 void blk_mq_delay_run_hw_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs); 321 bool blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async); 322 void blk_mq_run_hw_queues(struct request_queue *q, bool async); 323 void blk_mq_tagset_busy_iter(struct blk_mq_tag_set *tagset, 324 busy_tag_iter_fn *fn, void *priv); 325 void blk_mq_freeze_queue(struct request_queue *q); 326 void blk_mq_unfreeze_queue(struct request_queue *q); 327 void blk_freeze_queue_start(struct request_queue *q); 328 void blk_mq_freeze_queue_wait(struct request_queue *q); 329 int blk_mq_freeze_queue_wait_timeout(struct request_queue *q, 330 unsigned long timeout); 331 332 int blk_mq_map_queues(struct blk_mq_queue_map *qmap); 333 void blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set, int nr_hw_queues); 334 335 void blk_mq_quiesce_queue_nowait(struct request_queue *q); 336 337 unsigned int blk_mq_rq_cpu(struct request *rq); 338 339 /* 340 * Driver command data is immediately after the request. So subtract request 341 * size to get back to the original request, add request size to get the PDU. 342 */ 343 static inline struct request *blk_mq_rq_from_pdu(void *pdu) 344 { 345 return pdu - sizeof(struct request); 346 } 347 static inline void *blk_mq_rq_to_pdu(struct request *rq) 348 { 349 return rq + 1; 350 } 351 352 #define queue_for_each_hw_ctx(q, hctx, i) \ 353 for ((i) = 0; (i) < (q)->nr_hw_queues && \ 354 ({ hctx = (q)->queue_hw_ctx[i]; 1; }); (i)++) 355 356 #define hctx_for_each_ctx(hctx, ctx, i) \ 357 for ((i) = 0; (i) < (hctx)->nr_ctx && \ 358 ({ ctx = (hctx)->ctxs[(i)]; 1; }); (i)++) 359 360 static inline blk_qc_t request_to_qc_t(struct blk_mq_hw_ctx *hctx, 361 struct request *rq) 362 { 363 if (rq->tag != -1) 364 return rq->tag | (hctx->queue_num << BLK_QC_T_SHIFT); 365 366 return rq->internal_tag | (hctx->queue_num << BLK_QC_T_SHIFT) | 367 BLK_QC_T_INTERNAL; 368 } 369 370 #endif 371