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 /* Must be the last member - see also blk_mq_hw_ctx_size(). */
74 struct srcu_struct srcu[0];
77 struct blk_mq_queue_map {
79 unsigned int nr_queues;
80 unsigned int queue_offset;
84 HCTX_TYPE_DEFAULT, /* all I/O not otherwise accounted for */
85 HCTX_TYPE_READ, /* just for READ I/O */
86 HCTX_TYPE_POLL, /* polled I/O of any kind */
91 struct blk_mq_tag_set {
93 * map[] holds ctx -> hctx mappings, one map exists for each type
94 * that the driver wishes to support. There are no restrictions
95 * on maps being of the same size, and it's perfectly legal to
96 * share maps between types.
98 struct blk_mq_queue_map map[HCTX_MAX_TYPES];
99 unsigned int nr_maps; /* nr entries in map[] */
100 const struct blk_mq_ops *ops;
101 unsigned int nr_hw_queues; /* nr hw queues across maps */
102 unsigned int queue_depth; /* max hw supported */
103 unsigned int reserved_tags;
104 unsigned int cmd_size; /* per-request extra data */
106 unsigned int timeout;
107 unsigned int flags; /* BLK_MQ_F_* */
110 struct blk_mq_tags **tags;
112 struct mutex tag_list_lock;
113 struct list_head tag_list;
116 struct blk_mq_queue_data {
121 typedef blk_status_t (queue_rq_fn)(struct blk_mq_hw_ctx *,
122 const struct blk_mq_queue_data *);
123 typedef void (commit_rqs_fn)(struct blk_mq_hw_ctx *);
124 typedef bool (get_budget_fn)(struct blk_mq_hw_ctx *);
125 typedef void (put_budget_fn)(struct blk_mq_hw_ctx *);
126 typedef enum blk_eh_timer_return (timeout_fn)(struct request *, bool);
127 typedef int (init_hctx_fn)(struct blk_mq_hw_ctx *, void *, unsigned int);
128 typedef void (exit_hctx_fn)(struct blk_mq_hw_ctx *, unsigned int);
129 typedef int (init_request_fn)(struct blk_mq_tag_set *set, struct request *,
130 unsigned int, unsigned int);
131 typedef void (exit_request_fn)(struct blk_mq_tag_set *set, struct request *,
134 typedef bool (busy_iter_fn)(struct blk_mq_hw_ctx *, struct request *, void *,
136 typedef bool (busy_tag_iter_fn)(struct request *, void *, bool);
137 typedef int (poll_fn)(struct blk_mq_hw_ctx *);
138 typedef int (map_queues_fn)(struct blk_mq_tag_set *set);
139 typedef bool (busy_fn)(struct request_queue *);
140 typedef void (complete_fn)(struct request *);
147 queue_rq_fn *queue_rq;
150 * If a driver uses bd->last to judge when to submit requests to
151 * hardware, it must define this function. In case of errors that
152 * make us stop issuing further requests, this hook serves the
153 * purpose of kicking the hardware (which the last request otherwise
156 commit_rqs_fn *commit_rqs;
159 * Reserve budget before queue request, once .queue_rq is
160 * run, it is driver's responsibility to release the
161 * reserved budget. Also we have to handle failure case
162 * of .get_budget for avoiding I/O deadlock.
164 get_budget_fn *get_budget;
165 put_budget_fn *put_budget;
168 * Called on request timeout
173 * Called to poll for completion of a specific tag.
177 complete_fn *complete;
180 * Called when the block layer side of a hardware queue has been
181 * set up, allowing the driver to allocate/init matching structures.
182 * Ditto for exit/teardown.
184 init_hctx_fn *init_hctx;
185 exit_hctx_fn *exit_hctx;
188 * Called for every command allocated by the block layer to allow
189 * the driver to set up driver specific data.
191 * Tag greater than or equal to queue_depth is for setting up
194 * Ditto for exit/teardown.
196 init_request_fn *init_request;
197 exit_request_fn *exit_request;
198 /* Called from inside blk_get_request() */
199 void (*initialize_rq_fn)(struct request *rq);
202 * If set, returns whether or not this queue currently is busy
206 map_queues_fn *map_queues;
208 #ifdef CONFIG_BLK_DEBUG_FS
210 * Used by the debugfs implementation to show driver-specific
211 * information about a request.
213 void (*show_rq)(struct seq_file *m, struct request *rq);
218 BLK_MQ_F_SHOULD_MERGE = 1 << 0,
219 BLK_MQ_F_TAG_SHARED = 1 << 1,
220 BLK_MQ_F_BLOCKING = 1 << 5,
221 BLK_MQ_F_NO_SCHED = 1 << 6,
222 BLK_MQ_F_ALLOC_POLICY_START_BIT = 8,
223 BLK_MQ_F_ALLOC_POLICY_BITS = 1,
225 BLK_MQ_S_STOPPED = 0,
226 BLK_MQ_S_TAG_ACTIVE = 1,
227 BLK_MQ_S_SCHED_RESTART = 2,
229 BLK_MQ_MAX_DEPTH = 10240,
231 BLK_MQ_CPU_WORK_BATCH = 8,
233 #define BLK_MQ_FLAG_TO_ALLOC_POLICY(flags) \
234 ((flags >> BLK_MQ_F_ALLOC_POLICY_START_BIT) & \
235 ((1 << BLK_MQ_F_ALLOC_POLICY_BITS) - 1))
236 #define BLK_ALLOC_POLICY_TO_MQ_FLAG(policy) \
237 ((policy & ((1 << BLK_MQ_F_ALLOC_POLICY_BITS) - 1)) \
238 << BLK_MQ_F_ALLOC_POLICY_START_BIT)
240 struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *);
241 struct request_queue *blk_mq_init_allocated_queue(struct blk_mq_tag_set *set,
242 struct request_queue *q);
243 struct request_queue *blk_mq_init_sq_queue(struct blk_mq_tag_set *set,
244 const struct blk_mq_ops *ops,
245 unsigned int queue_depth,
246 unsigned int set_flags);
247 int blk_mq_register_dev(struct device *, struct request_queue *);
248 void blk_mq_unregister_dev(struct device *, struct request_queue *);
250 int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set);
251 void blk_mq_free_tag_set(struct blk_mq_tag_set *set);
253 void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule);
255 void blk_mq_free_request(struct request *rq);
256 bool blk_mq_can_queue(struct blk_mq_hw_ctx *);
258 bool blk_mq_queue_inflight(struct request_queue *q);
261 /* return when out of requests */
262 BLK_MQ_REQ_NOWAIT = (__force blk_mq_req_flags_t)(1 << 0),
263 /* allocate from reserved pool */
264 BLK_MQ_REQ_RESERVED = (__force blk_mq_req_flags_t)(1 << 1),
265 /* allocate internal/sched tag */
266 BLK_MQ_REQ_INTERNAL = (__force blk_mq_req_flags_t)(1 << 2),
267 /* set RQF_PREEMPT */
268 BLK_MQ_REQ_PREEMPT = (__force blk_mq_req_flags_t)(1 << 3),
271 struct request *blk_mq_alloc_request(struct request_queue *q, unsigned int op,
272 blk_mq_req_flags_t flags);
273 struct request *blk_mq_alloc_request_hctx(struct request_queue *q,
274 unsigned int op, blk_mq_req_flags_t flags,
275 unsigned int hctx_idx);
276 struct request *blk_mq_tag_to_rq(struct blk_mq_tags *tags, unsigned int tag);
279 BLK_MQ_UNIQUE_TAG_BITS = 16,
280 BLK_MQ_UNIQUE_TAG_MASK = (1 << BLK_MQ_UNIQUE_TAG_BITS) - 1,
283 u32 blk_mq_unique_tag(struct request *rq);
285 static inline u16 blk_mq_unique_tag_to_hwq(u32 unique_tag)
287 return unique_tag >> BLK_MQ_UNIQUE_TAG_BITS;
290 static inline u16 blk_mq_unique_tag_to_tag(u32 unique_tag)
292 return unique_tag & BLK_MQ_UNIQUE_TAG_MASK;
296 int blk_mq_request_started(struct request *rq);
297 void blk_mq_start_request(struct request *rq);
298 void blk_mq_end_request(struct request *rq, blk_status_t error);
299 void __blk_mq_end_request(struct request *rq, blk_status_t error);
301 void blk_mq_requeue_request(struct request *rq, bool kick_requeue_list);
302 void blk_mq_kick_requeue_list(struct request_queue *q);
303 void blk_mq_delay_kick_requeue_list(struct request_queue *q, unsigned long msecs);
304 bool blk_mq_complete_request(struct request *rq);
305 bool blk_mq_bio_list_merge(struct request_queue *q, struct list_head *list,
307 bool blk_mq_queue_stopped(struct request_queue *q);
308 void blk_mq_stop_hw_queue(struct blk_mq_hw_ctx *hctx);
309 void blk_mq_start_hw_queue(struct blk_mq_hw_ctx *hctx);
310 void blk_mq_stop_hw_queues(struct request_queue *q);
311 void blk_mq_start_hw_queues(struct request_queue *q);
312 void blk_mq_start_stopped_hw_queue(struct blk_mq_hw_ctx *hctx, bool async);
313 void blk_mq_start_stopped_hw_queues(struct request_queue *q, bool async);
314 void blk_mq_quiesce_queue(struct request_queue *q);
315 void blk_mq_unquiesce_queue(struct request_queue *q);
316 void blk_mq_delay_run_hw_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs);
317 bool blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async);
318 void blk_mq_run_hw_queues(struct request_queue *q, bool async);
319 void blk_mq_tagset_busy_iter(struct blk_mq_tag_set *tagset,
320 busy_tag_iter_fn *fn, void *priv);
321 void blk_mq_freeze_queue(struct request_queue *q);
322 void blk_mq_unfreeze_queue(struct request_queue *q);
323 void blk_freeze_queue_start(struct request_queue *q);
324 void blk_mq_freeze_queue_wait(struct request_queue *q);
325 int blk_mq_freeze_queue_wait_timeout(struct request_queue *q,
326 unsigned long timeout);
328 int blk_mq_map_queues(struct blk_mq_queue_map *qmap);
329 void blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set, int nr_hw_queues);
331 void blk_mq_quiesce_queue_nowait(struct request_queue *q);
333 unsigned int blk_mq_rq_cpu(struct request *rq);
336 * Driver command data is immediately after the request. So subtract request
337 * size to get back to the original request, add request size to get the PDU.
339 static inline struct request *blk_mq_rq_from_pdu(void *pdu)
341 return pdu - sizeof(struct request);
343 static inline void *blk_mq_rq_to_pdu(struct request *rq)
348 #define queue_for_each_hw_ctx(q, hctx, i) \
349 for ((i) = 0; (i) < (q)->nr_hw_queues && \
350 ({ hctx = (q)->queue_hw_ctx[i]; 1; }); (i)++)
352 #define hctx_for_each_ctx(hctx, ctx, i) \
353 for ((i) = 0; (i) < (hctx)->nr_ctx && \
354 ({ ctx = (hctx)->ctxs[(i)]; 1; }); (i)++)
356 static inline blk_qc_t request_to_qc_t(struct blk_mq_hw_ctx *hctx,
360 return rq->tag | (hctx->queue_num << BLK_QC_T_SHIFT);
362 return rq->internal_tag | (hctx->queue_num << BLK_QC_T_SHIFT) |