1 /* SPDX-License-Identifier: GPL-2.0 */
5 #include <linux/blkdev.h>
6 #include <linux/sbitmap.h>
7 #include <linux/srcu.h>
10 struct blk_flush_queue;
13 * struct blk_mq_hw_ctx - State for a hardware queue facing the hardware block device
15 struct blk_mq_hw_ctx {
18 struct list_head dispatch;
19 unsigned long state; /* BLK_MQ_S_* flags */
20 } ____cacheline_aligned_in_smp;
22 struct delayed_work run_work;
23 cpumask_var_t cpumask;
27 unsigned long flags; /* BLK_MQ_F_* flags */
30 struct request_queue *queue;
31 struct blk_flush_queue *fq;
35 struct sbitmap ctx_map;
37 struct blk_mq_ctx *dispatch_from;
38 unsigned int dispatch_busy;
41 unsigned short nr_ctx;
42 struct blk_mq_ctx **ctxs;
44 spinlock_t dispatch_wait_lock;
45 wait_queue_entry_t dispatch_wait;
48 struct blk_mq_tags *tags;
49 struct blk_mq_tags *sched_tags;
53 #define BLK_MQ_MAX_DISPATCH_ORDER 7
54 unsigned long dispatched[BLK_MQ_MAX_DISPATCH_ORDER];
56 unsigned int numa_node;
57 unsigned int queue_num;
61 struct hlist_node cpuhp_dead;
64 unsigned long poll_considered;
65 unsigned long poll_invoked;
66 unsigned long poll_success;
68 #ifdef CONFIG_BLK_DEBUG_FS
69 struct dentry *debugfs_dir;
70 struct dentry *sched_debugfs_dir;
73 struct list_head hctx_list;
75 /* Must be the last member - see also blk_mq_hw_ctx_size(). */
76 struct srcu_struct srcu[0];
79 struct blk_mq_queue_map {
81 unsigned int nr_queues;
82 unsigned int queue_offset;
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 */
93 struct blk_mq_tag_set {
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.
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 */
108 unsigned int timeout;
109 unsigned int flags; /* BLK_MQ_F_* */
112 struct blk_mq_tags **tags;
114 struct mutex tag_list_lock;
115 struct list_head tag_list;
118 struct blk_mq_queue_data {
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 *,
136 typedef bool (busy_iter_fn)(struct blk_mq_hw_ctx *, struct request *, void *,
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 typedef void (cleanup_rq_fn)(struct request *);
150 queue_rq_fn *queue_rq;
153 * If a driver uses bd->last to judge when to submit requests to
154 * hardware, it must define this function. In case of errors that
155 * make us stop issuing further requests, this hook serves the
156 * purpose of kicking the hardware (which the last request otherwise
159 commit_rqs_fn *commit_rqs;
162 * Reserve budget before queue request, once .queue_rq is
163 * run, it is driver's responsibility to release the
164 * reserved budget. Also we have to handle failure case
165 * of .get_budget for avoiding I/O deadlock.
167 get_budget_fn *get_budget;
168 put_budget_fn *put_budget;
171 * Called on request timeout
176 * Called to poll for completion of a specific tag.
180 complete_fn *complete;
183 * Called when the block layer side of a hardware queue has been
184 * set up, allowing the driver to allocate/init matching structures.
185 * Ditto for exit/teardown.
187 init_hctx_fn *init_hctx;
188 exit_hctx_fn *exit_hctx;
191 * Called for every command allocated by the block layer to allow
192 * the driver to set up driver specific data.
194 * Tag greater than or equal to queue_depth is for setting up
197 * Ditto for exit/teardown.
199 init_request_fn *init_request;
200 exit_request_fn *exit_request;
201 /* Called from inside blk_get_request() */
202 void (*initialize_rq_fn)(struct request *rq);
205 * Called before freeing one request which isn't completed yet,
206 * and usually for freeing the driver private data
208 cleanup_rq_fn *cleanup_rq;
211 * If set, returns whether or not this queue currently is busy
215 map_queues_fn *map_queues;
217 #ifdef CONFIG_BLK_DEBUG_FS
219 * Used by the debugfs implementation to show driver-specific
220 * information about a request.
222 void (*show_rq)(struct seq_file *m, struct request *rq);
227 BLK_MQ_F_SHOULD_MERGE = 1 << 0,
228 BLK_MQ_F_TAG_SHARED = 1 << 1,
229 BLK_MQ_F_BLOCKING = 1 << 5,
230 BLK_MQ_F_NO_SCHED = 1 << 6,
231 BLK_MQ_F_ALLOC_POLICY_START_BIT = 8,
232 BLK_MQ_F_ALLOC_POLICY_BITS = 1,
234 BLK_MQ_S_STOPPED = 0,
235 BLK_MQ_S_TAG_ACTIVE = 1,
236 BLK_MQ_S_SCHED_RESTART = 2,
238 BLK_MQ_MAX_DEPTH = 10240,
240 BLK_MQ_CPU_WORK_BATCH = 8,
242 #define BLK_MQ_FLAG_TO_ALLOC_POLICY(flags) \
243 ((flags >> BLK_MQ_F_ALLOC_POLICY_START_BIT) & \
244 ((1 << BLK_MQ_F_ALLOC_POLICY_BITS) - 1))
245 #define BLK_ALLOC_POLICY_TO_MQ_FLAG(policy) \
246 ((policy & ((1 << BLK_MQ_F_ALLOC_POLICY_BITS) - 1)) \
247 << BLK_MQ_F_ALLOC_POLICY_START_BIT)
249 struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *);
250 struct request_queue *blk_mq_init_allocated_queue(struct blk_mq_tag_set *set,
251 struct request_queue *q,
253 struct request_queue *blk_mq_init_sq_queue(struct blk_mq_tag_set *set,
254 const struct blk_mq_ops *ops,
255 unsigned int queue_depth,
256 unsigned int set_flags);
257 void blk_mq_unregister_dev(struct device *, struct request_queue *);
259 int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set);
260 void blk_mq_free_tag_set(struct blk_mq_tag_set *set);
262 void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule);
264 void blk_mq_free_request(struct request *rq);
265 bool blk_mq_can_queue(struct blk_mq_hw_ctx *);
267 bool blk_mq_queue_inflight(struct request_queue *q);
270 /* return when out of requests */
271 BLK_MQ_REQ_NOWAIT = (__force blk_mq_req_flags_t)(1 << 0),
272 /* allocate from reserved pool */
273 BLK_MQ_REQ_RESERVED = (__force blk_mq_req_flags_t)(1 << 1),
274 /* allocate internal/sched tag */
275 BLK_MQ_REQ_INTERNAL = (__force blk_mq_req_flags_t)(1 << 2),
276 /* set RQF_PREEMPT */
277 BLK_MQ_REQ_PREEMPT = (__force blk_mq_req_flags_t)(1 << 3),
280 struct request *blk_mq_alloc_request(struct request_queue *q, unsigned int op,
281 blk_mq_req_flags_t flags);
282 struct request *blk_mq_alloc_request_hctx(struct request_queue *q,
283 unsigned int op, blk_mq_req_flags_t flags,
284 unsigned int hctx_idx);
285 struct request *blk_mq_tag_to_rq(struct blk_mq_tags *tags, unsigned int tag);
288 BLK_MQ_UNIQUE_TAG_BITS = 16,
289 BLK_MQ_UNIQUE_TAG_MASK = (1 << BLK_MQ_UNIQUE_TAG_BITS) - 1,
292 u32 blk_mq_unique_tag(struct request *rq);
294 static inline u16 blk_mq_unique_tag_to_hwq(u32 unique_tag)
296 return unique_tag >> BLK_MQ_UNIQUE_TAG_BITS;
299 static inline u16 blk_mq_unique_tag_to_tag(u32 unique_tag)
301 return unique_tag & BLK_MQ_UNIQUE_TAG_MASK;
305 int blk_mq_request_started(struct request *rq);
306 int blk_mq_request_completed(struct request *rq);
307 void blk_mq_start_request(struct request *rq);
308 void blk_mq_end_request(struct request *rq, blk_status_t error);
309 void __blk_mq_end_request(struct request *rq, blk_status_t error);
311 void blk_mq_requeue_request(struct request *rq, bool kick_requeue_list);
312 void blk_mq_kick_requeue_list(struct request_queue *q);
313 void blk_mq_delay_kick_requeue_list(struct request_queue *q, unsigned long msecs);
314 bool blk_mq_complete_request(struct request *rq);
315 bool blk_mq_bio_list_merge(struct request_queue *q, struct list_head *list,
316 struct bio *bio, unsigned int nr_segs);
317 bool blk_mq_queue_stopped(struct request_queue *q);
318 void blk_mq_stop_hw_queue(struct blk_mq_hw_ctx *hctx);
319 void blk_mq_start_hw_queue(struct blk_mq_hw_ctx *hctx);
320 void blk_mq_stop_hw_queues(struct request_queue *q);
321 void blk_mq_start_hw_queues(struct request_queue *q);
322 void blk_mq_start_stopped_hw_queue(struct blk_mq_hw_ctx *hctx, bool async);
323 void blk_mq_start_stopped_hw_queues(struct request_queue *q, bool async);
324 void blk_mq_quiesce_queue(struct request_queue *q);
325 void blk_mq_unquiesce_queue(struct request_queue *q);
326 void blk_mq_delay_run_hw_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs);
327 bool blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async);
328 void blk_mq_run_hw_queues(struct request_queue *q, bool async);
329 void blk_mq_tagset_busy_iter(struct blk_mq_tag_set *tagset,
330 busy_tag_iter_fn *fn, void *priv);
331 void blk_mq_tagset_wait_completed_request(struct blk_mq_tag_set *tagset);
332 void blk_mq_freeze_queue(struct request_queue *q);
333 void blk_mq_unfreeze_queue(struct request_queue *q);
334 void blk_freeze_queue_start(struct request_queue *q);
335 void blk_mq_freeze_queue_wait(struct request_queue *q);
336 int blk_mq_freeze_queue_wait_timeout(struct request_queue *q,
337 unsigned long timeout);
339 int blk_mq_map_queues(struct blk_mq_queue_map *qmap);
340 void blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set, int nr_hw_queues);
342 void blk_mq_quiesce_queue_nowait(struct request_queue *q);
344 unsigned int blk_mq_rq_cpu(struct request *rq);
347 * Driver command data is immediately after the request. So subtract request
348 * size to get back to the original request, add request size to get the PDU.
350 static inline struct request *blk_mq_rq_from_pdu(void *pdu)
352 return pdu - sizeof(struct request);
354 static inline void *blk_mq_rq_to_pdu(struct request *rq)
359 #define queue_for_each_hw_ctx(q, hctx, i) \
360 for ((i) = 0; (i) < (q)->nr_hw_queues && \
361 ({ hctx = (q)->queue_hw_ctx[i]; 1; }); (i)++)
363 #define hctx_for_each_ctx(hctx, ctx, i) \
364 for ((i) = 0; (i) < (hctx)->nr_ctx && \
365 ({ ctx = (hctx)->ctxs[(i)]; 1; }); (i)++)
367 static inline blk_qc_t request_to_qc_t(struct blk_mq_hw_ctx *hctx,
371 return rq->tag | (hctx->queue_num << BLK_QC_T_SHIFT);
373 return rq->internal_tag | (hctx->queue_num << BLK_QC_T_SHIFT) |
377 static inline void blk_mq_cleanup_rq(struct request *rq)
379 if (rq->q->mq_ops->cleanup_rq)
380 rq->q->mq_ops->cleanup_rq(rq);