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 61 struct hlist_node cpuhp_dead; 62 struct kobject kobj; 63 64 unsigned long poll_considered; 65 unsigned long poll_invoked; 66 unsigned long poll_success; 67 68 #ifdef CONFIG_BLK_DEBUG_FS 69 struct dentry *debugfs_dir; 70 struct dentry *sched_debugfs_dir; 71 #endif 72 73 struct list_head hctx_list; 74 75 /* Must be the last member - see also blk_mq_hw_ctx_size(). */ 76 struct srcu_struct srcu[0]; 77 }; 78 79 struct blk_mq_queue_map { 80 unsigned int *mq_map; 81 unsigned int nr_queues; 82 unsigned int queue_offset; 83 }; 84 85 enum hctx_type { 86 HCTX_TYPE_DEFAULT, /* all I/O not otherwise accounted for */ 87 HCTX_TYPE_READ, /* just for READ I/O */ 88 HCTX_TYPE_POLL, /* polled I/O of any kind */ 89 90 HCTX_MAX_TYPES, 91 }; 92 93 struct blk_mq_tag_set { 94 /* 95 * map[] holds ctx -> hctx mappings, one map exists for each type 96 * that the driver wishes to support. There are no restrictions 97 * on maps being of the same size, and it's perfectly legal to 98 * share maps between types. 99 */ 100 struct blk_mq_queue_map map[HCTX_MAX_TYPES]; 101 unsigned int nr_maps; /* nr entries in map[] */ 102 const struct blk_mq_ops *ops; 103 unsigned int nr_hw_queues; /* nr hw queues across maps */ 104 unsigned int queue_depth; /* max hw supported */ 105 unsigned int reserved_tags; 106 unsigned int cmd_size; /* per-request extra data */ 107 int numa_node; 108 unsigned int timeout; 109 unsigned int flags; /* BLK_MQ_F_* */ 110 void *driver_data; 111 112 struct blk_mq_tags **tags; 113 114 struct mutex tag_list_lock; 115 struct list_head tag_list; 116 }; 117 118 struct blk_mq_queue_data { 119 struct request *rq; 120 bool last; 121 }; 122 123 typedef blk_status_t (queue_rq_fn)(struct blk_mq_hw_ctx *, 124 const struct blk_mq_queue_data *); 125 typedef void (commit_rqs_fn)(struct blk_mq_hw_ctx *); 126 typedef bool (get_budget_fn)(struct blk_mq_hw_ctx *); 127 typedef void (put_budget_fn)(struct blk_mq_hw_ctx *); 128 typedef enum blk_eh_timer_return (timeout_fn)(struct request *, bool); 129 typedef int (init_hctx_fn)(struct blk_mq_hw_ctx *, void *, unsigned int); 130 typedef void (exit_hctx_fn)(struct blk_mq_hw_ctx *, unsigned int); 131 typedef int (init_request_fn)(struct blk_mq_tag_set *set, struct request *, 132 unsigned int, unsigned int); 133 typedef void (exit_request_fn)(struct blk_mq_tag_set *set, struct request *, 134 unsigned int); 135 136 typedef bool (busy_iter_fn)(struct blk_mq_hw_ctx *, struct request *, void *, 137 bool); 138 typedef bool (busy_tag_iter_fn)(struct request *, void *, bool); 139 typedef int (poll_fn)(struct blk_mq_hw_ctx *); 140 typedef int (map_queues_fn)(struct blk_mq_tag_set *set); 141 typedef bool (busy_fn)(struct request_queue *); 142 typedef void (complete_fn)(struct request *); 143 144 145 struct blk_mq_ops { 146 /* 147 * Queue request 148 */ 149 queue_rq_fn *queue_rq; 150 151 /* 152 * If a driver uses bd->last to judge when to submit requests to 153 * hardware, it must define this function. In case of errors that 154 * make us stop issuing further requests, this hook serves the 155 * purpose of kicking the hardware (which the last request otherwise 156 * would have done). 157 */ 158 commit_rqs_fn *commit_rqs; 159 160 /* 161 * Reserve budget before queue request, once .queue_rq is 162 * run, it is driver's responsibility to release the 163 * reserved budget. Also we have to handle failure case 164 * of .get_budget for avoiding I/O deadlock. 165 */ 166 get_budget_fn *get_budget; 167 put_budget_fn *put_budget; 168 169 /* 170 * Called on request timeout 171 */ 172 timeout_fn *timeout; 173 174 /* 175 * Called to poll for completion of a specific tag. 176 */ 177 poll_fn *poll; 178 179 complete_fn *complete; 180 181 /* 182 * Called when the block layer side of a hardware queue has been 183 * set up, allowing the driver to allocate/init matching structures. 184 * Ditto for exit/teardown. 185 */ 186 init_hctx_fn *init_hctx; 187 exit_hctx_fn *exit_hctx; 188 189 /* 190 * Called for every command allocated by the block layer to allow 191 * the driver to set up driver specific data. 192 * 193 * Tag greater than or equal to queue_depth is for setting up 194 * flush request. 195 * 196 * Ditto for exit/teardown. 197 */ 198 init_request_fn *init_request; 199 exit_request_fn *exit_request; 200 /* Called from inside blk_get_request() */ 201 void (*initialize_rq_fn)(struct request *rq); 202 203 /* 204 * If set, returns whether or not this queue currently is busy 205 */ 206 busy_fn *busy; 207 208 map_queues_fn *map_queues; 209 210 #ifdef CONFIG_BLK_DEBUG_FS 211 /* 212 * Used by the debugfs implementation to show driver-specific 213 * information about a request. 214 */ 215 void (*show_rq)(struct seq_file *m, struct request *rq); 216 #endif 217 }; 218 219 enum { 220 BLK_MQ_F_SHOULD_MERGE = 1 << 0, 221 BLK_MQ_F_TAG_SHARED = 1 << 1, 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_kick_requeue_list(struct request_queue *q); 305 void blk_mq_delay_kick_requeue_list(struct request_queue *q, unsigned long msecs); 306 bool blk_mq_complete_request(struct request *rq); 307 void blk_mq_complete_request_sync(struct request *rq); 308 bool blk_mq_bio_list_merge(struct request_queue *q, struct list_head *list, 309 struct bio *bio, unsigned int nr_segs); 310 bool blk_mq_queue_stopped(struct request_queue *q); 311 void blk_mq_stop_hw_queue(struct blk_mq_hw_ctx *hctx); 312 void blk_mq_start_hw_queue(struct blk_mq_hw_ctx *hctx); 313 void blk_mq_stop_hw_queues(struct request_queue *q); 314 void blk_mq_start_hw_queues(struct request_queue *q); 315 void blk_mq_start_stopped_hw_queue(struct blk_mq_hw_ctx *hctx, bool async); 316 void blk_mq_start_stopped_hw_queues(struct request_queue *q, bool async); 317 void blk_mq_quiesce_queue(struct request_queue *q); 318 void blk_mq_unquiesce_queue(struct request_queue *q); 319 void blk_mq_delay_run_hw_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs); 320 bool blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async); 321 void blk_mq_run_hw_queues(struct request_queue *q, bool async); 322 void blk_mq_tagset_busy_iter(struct blk_mq_tag_set *tagset, 323 busy_tag_iter_fn *fn, void *priv); 324 void blk_mq_freeze_queue(struct request_queue *q); 325 void blk_mq_unfreeze_queue(struct request_queue *q); 326 void blk_freeze_queue_start(struct request_queue *q); 327 void blk_mq_freeze_queue_wait(struct request_queue *q); 328 int blk_mq_freeze_queue_wait_timeout(struct request_queue *q, 329 unsigned long timeout); 330 331 int blk_mq_map_queues(struct blk_mq_queue_map *qmap); 332 void blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set, int nr_hw_queues); 333 334 void blk_mq_quiesce_queue_nowait(struct request_queue *q); 335 336 unsigned int blk_mq_rq_cpu(struct request *rq); 337 338 /* 339 * Driver command data is immediately after the request. So subtract request 340 * size to get back to the original request, add request size to get the PDU. 341 */ 342 static inline struct request *blk_mq_rq_from_pdu(void *pdu) 343 { 344 return pdu - sizeof(struct request); 345 } 346 static inline void *blk_mq_rq_to_pdu(struct request *rq) 347 { 348 return rq + 1; 349 } 350 351 #define queue_for_each_hw_ctx(q, hctx, i) \ 352 for ((i) = 0; (i) < (q)->nr_hw_queues && \ 353 ({ hctx = (q)->queue_hw_ctx[i]; 1; }); (i)++) 354 355 #define hctx_for_each_ctx(hctx, ctx, i) \ 356 for ((i) = 0; (i) < (hctx)->nr_ctx && \ 357 ({ ctx = (hctx)->ctxs[(i)]; 1; }); (i)++) 358 359 static inline blk_qc_t request_to_qc_t(struct blk_mq_hw_ctx *hctx, 360 struct request *rq) 361 { 362 if (rq->tag != -1) 363 return rq->tag | (hctx->queue_num << BLK_QC_T_SHIFT); 364 365 return rq->internal_tag | (hctx->queue_num << BLK_QC_T_SHIFT) | 366 BLK_QC_T_INTERNAL; 367 } 368 369 #endif 370