1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef INT_BLK_MQ_H
3#define INT_BLK_MQ_H
4
5#include <linux/blk-mq.h>
6#include "blk-stat.h"
7
8struct blk_mq_tag_set;
9
10struct 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 */
18struct 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 struct request_queue *queue;
29 struct blk_mq_ctxs *ctxs;
30 struct kobject kobj;
31} ____cacheline_aligned_in_smp;
32
33enum {
34 BLK_MQ_NO_TAG = -1U,
35 BLK_MQ_TAG_MIN = 1,
36 BLK_MQ_TAG_MAX = BLK_MQ_NO_TAG - 1,
37};
38
39typedef unsigned int __bitwise blk_insert_t;
40#define BLK_MQ_INSERT_AT_HEAD ((__force blk_insert_t)0x01)
41
42void blk_mq_submit_bio(struct bio *bio);
43int blk_mq_poll(struct request_queue *q, blk_qc_t cookie, struct io_comp_batch *iob,
44 unsigned int flags);
45void blk_mq_exit_queue(struct request_queue *q);
46int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr);
47void blk_mq_wake_waiters(struct request_queue *q);
48bool blk_mq_dispatch_rq_list(struct blk_mq_hw_ctx *hctx, struct list_head *,
49 unsigned int);
50void blk_mq_flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, struct list_head *list);
51struct request *blk_mq_dequeue_from_ctx(struct blk_mq_hw_ctx *hctx,
52 struct blk_mq_ctx *start);
53void blk_mq_put_rq_ref(struct request *rq);
54
55/*
56 * Internal helpers for allocating/freeing the request map
57 */
58void blk_mq_free_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
59 unsigned int hctx_idx);
60void blk_mq_free_rq_map(struct blk_mq_tags *tags);
61struct blk_mq_tags *blk_mq_alloc_map_and_rqs(struct blk_mq_tag_set *set,
62 unsigned int hctx_idx, unsigned int depth);
63void blk_mq_free_map_and_rqs(struct blk_mq_tag_set *set,
64 struct blk_mq_tags *tags,
65 unsigned int hctx_idx);
66
67/*
68 * CPU -> queue mappings
69 */
70extern int blk_mq_hw_queue_to_node(struct blk_mq_queue_map *qmap, unsigned int);
71
72/*
73 * blk_mq_map_queue_type() - map (hctx_type,cpu) to hardware queue
74 * @q: request queue
75 * @type: the hctx type index
76 * @cpu: CPU
77 */
78static inline struct blk_mq_hw_ctx *blk_mq_map_queue_type(struct request_queue *q,
79 enum hctx_type type,
80 unsigned int cpu)
81{
82 return xa_load(&q->hctx_table, index: q->tag_set->map[type].mq_map[cpu]);
83}
84
85static inline enum hctx_type blk_mq_get_hctx_type(blk_opf_t opf)
86{
87 enum hctx_type type = HCTX_TYPE_DEFAULT;
88
89 /*
90 * The caller ensure that if REQ_POLLED, poll must be enabled.
91 */
92 if (opf & REQ_POLLED)
93 type = HCTX_TYPE_POLL;
94 else if ((opf & REQ_OP_MASK) == REQ_OP_READ)
95 type = HCTX_TYPE_READ;
96 return type;
97}
98
99/*
100 * blk_mq_map_queue() - map (cmd_flags,type) to hardware queue
101 * @q: request queue
102 * @opf: operation type (REQ_OP_*) and flags (e.g. REQ_POLLED).
103 * @ctx: software queue cpu ctx
104 */
105static inline struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q,
106 blk_opf_t opf,
107 struct blk_mq_ctx *ctx)
108{
109 return ctx->hctxs[blk_mq_get_hctx_type(opf)];
110}
111
112/*
113 * sysfs helpers
114 */
115extern void blk_mq_sysfs_init(struct request_queue *q);
116extern void blk_mq_sysfs_deinit(struct request_queue *q);
117int blk_mq_sysfs_register(struct gendisk *disk);
118void blk_mq_sysfs_unregister(struct gendisk *disk);
119int blk_mq_sysfs_register_hctxs(struct request_queue *q);
120void blk_mq_sysfs_unregister_hctxs(struct request_queue *q);
121extern void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx);
122void blk_mq_free_plug_rqs(struct blk_plug *plug);
123void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule);
124
125void blk_mq_cancel_work_sync(struct request_queue *q);
126
127void blk_mq_release(struct request_queue *q);
128
129static inline struct blk_mq_ctx *__blk_mq_get_ctx(struct request_queue *q,
130 unsigned int cpu)
131{
132 return per_cpu_ptr(q->queue_ctx, cpu);
133}
134
135/*
136 * This assumes per-cpu software queueing queues. They could be per-node
137 * as well, for instance. For now this is hardcoded as-is. Note that we don't
138 * care about preemption, since we know the ctx's are persistent. This does
139 * mean that we can't rely on ctx always matching the currently running CPU.
140 */
141static inline struct blk_mq_ctx *blk_mq_get_ctx(struct request_queue *q)
142{
143 return __blk_mq_get_ctx(q, raw_smp_processor_id());
144}
145
146struct blk_mq_alloc_data {
147 /* input parameter */
148 struct request_queue *q;
149 blk_mq_req_flags_t flags;
150 unsigned int shallow_depth;
151 blk_opf_t cmd_flags;
152 req_flags_t rq_flags;
153
154 /* allocate multiple requests/tags in one go */
155 unsigned int nr_tags;
156 struct request **cached_rq;
157
158 /* input & output parameter */
159 struct blk_mq_ctx *ctx;
160 struct blk_mq_hw_ctx *hctx;
161};
162
163struct blk_mq_tags *blk_mq_init_tags(unsigned int nr_tags,
164 unsigned int reserved_tags, int node, int alloc_policy);
165void blk_mq_free_tags(struct blk_mq_tags *tags);
166int blk_mq_init_bitmaps(struct sbitmap_queue *bitmap_tags,
167 struct sbitmap_queue *breserved_tags, unsigned int queue_depth,
168 unsigned int reserved, int node, int alloc_policy);
169
170unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data);
171unsigned long blk_mq_get_tags(struct blk_mq_alloc_data *data, int nr_tags,
172 unsigned int *offset);
173void blk_mq_put_tag(struct blk_mq_tags *tags, struct blk_mq_ctx *ctx,
174 unsigned int tag);
175void blk_mq_put_tags(struct blk_mq_tags *tags, int *tag_array, int nr_tags);
176int blk_mq_tag_update_depth(struct blk_mq_hw_ctx *hctx,
177 struct blk_mq_tags **tags, unsigned int depth, bool can_grow);
178void blk_mq_tag_resize_shared_tags(struct blk_mq_tag_set *set,
179 unsigned int size);
180void blk_mq_tag_update_sched_shared_tags(struct request_queue *q);
181
182void blk_mq_tag_wakeup_all(struct blk_mq_tags *tags, bool);
183void blk_mq_queue_tag_busy_iter(struct request_queue *q, busy_tag_iter_fn *fn,
184 void *priv);
185void blk_mq_all_tag_iter(struct blk_mq_tags *tags, busy_tag_iter_fn *fn,
186 void *priv);
187
188static inline struct sbq_wait_state *bt_wait_ptr(struct sbitmap_queue *bt,
189 struct blk_mq_hw_ctx *hctx)
190{
191 if (!hctx)
192 return &bt->ws[0];
193 return sbq_wait_ptr(sbq: bt, wait_index: &hctx->wait_index);
194}
195
196void __blk_mq_tag_busy(struct blk_mq_hw_ctx *);
197void __blk_mq_tag_idle(struct blk_mq_hw_ctx *);
198
199static inline void blk_mq_tag_busy(struct blk_mq_hw_ctx *hctx)
200{
201 if (hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED)
202 __blk_mq_tag_busy(hctx);
203}
204
205static inline void blk_mq_tag_idle(struct blk_mq_hw_ctx *hctx)
206{
207 if (hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED)
208 __blk_mq_tag_idle(hctx);
209}
210
211static inline bool blk_mq_tag_is_reserved(struct blk_mq_tags *tags,
212 unsigned int tag)
213{
214 return tag < tags->nr_reserved_tags;
215}
216
217static inline bool blk_mq_is_shared_tags(unsigned int flags)
218{
219 return flags & BLK_MQ_F_TAG_HCTX_SHARED;
220}
221
222static inline struct blk_mq_tags *blk_mq_tags_from_data(struct blk_mq_alloc_data *data)
223{
224 if (data->rq_flags & RQF_SCHED_TAGS)
225 return data->hctx->sched_tags;
226 return data->hctx->tags;
227}
228
229static inline bool blk_mq_hctx_stopped(struct blk_mq_hw_ctx *hctx)
230{
231 return test_bit(BLK_MQ_S_STOPPED, &hctx->state);
232}
233
234static inline bool blk_mq_hw_queue_mapped(struct blk_mq_hw_ctx *hctx)
235{
236 return hctx->nr_ctx && hctx->tags;
237}
238
239unsigned int blk_mq_in_flight(struct request_queue *q,
240 struct block_device *part);
241void blk_mq_in_flight_rw(struct request_queue *q, struct block_device *part,
242 unsigned int inflight[2]);
243
244static inline void blk_mq_put_dispatch_budget(struct request_queue *q,
245 int budget_token)
246{
247 if (q->mq_ops->put_budget)
248 q->mq_ops->put_budget(q, budget_token);
249}
250
251static inline int blk_mq_get_dispatch_budget(struct request_queue *q)
252{
253 if (q->mq_ops->get_budget)
254 return q->mq_ops->get_budget(q);
255 return 0;
256}
257
258static inline void blk_mq_set_rq_budget_token(struct request *rq, int token)
259{
260 if (token < 0)
261 return;
262
263 if (rq->q->mq_ops->set_rq_budget_token)
264 rq->q->mq_ops->set_rq_budget_token(rq, token);
265}
266
267static inline int blk_mq_get_rq_budget_token(struct request *rq)
268{
269 if (rq->q->mq_ops->get_rq_budget_token)
270 return rq->q->mq_ops->get_rq_budget_token(rq);
271 return -1;
272}
273
274static inline void __blk_mq_add_active_requests(struct blk_mq_hw_ctx *hctx,
275 int val)
276{
277 if (blk_mq_is_shared_tags(flags: hctx->flags))
278 atomic_add(i: val, v: &hctx->queue->nr_active_requests_shared_tags);
279 else
280 atomic_add(i: val, v: &hctx->nr_active);
281}
282
283static inline void __blk_mq_inc_active_requests(struct blk_mq_hw_ctx *hctx)
284{
285 __blk_mq_add_active_requests(hctx, val: 1);
286}
287
288static inline void __blk_mq_sub_active_requests(struct blk_mq_hw_ctx *hctx,
289 int val)
290{
291 if (blk_mq_is_shared_tags(flags: hctx->flags))
292 atomic_sub(i: val, v: &hctx->queue->nr_active_requests_shared_tags);
293 else
294 atomic_sub(i: val, v: &hctx->nr_active);
295}
296
297static inline void __blk_mq_dec_active_requests(struct blk_mq_hw_ctx *hctx)
298{
299 __blk_mq_sub_active_requests(hctx, val: 1);
300}
301
302static inline void blk_mq_add_active_requests(struct blk_mq_hw_ctx *hctx,
303 int val)
304{
305 if (hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED)
306 __blk_mq_add_active_requests(hctx, val);
307}
308
309static inline void blk_mq_inc_active_requests(struct blk_mq_hw_ctx *hctx)
310{
311 if (hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED)
312 __blk_mq_inc_active_requests(hctx);
313}
314
315static inline void blk_mq_sub_active_requests(struct blk_mq_hw_ctx *hctx,
316 int val)
317{
318 if (hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED)
319 __blk_mq_sub_active_requests(hctx, val);
320}
321
322static inline void blk_mq_dec_active_requests(struct blk_mq_hw_ctx *hctx)
323{
324 if (hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED)
325 __blk_mq_dec_active_requests(hctx);
326}
327
328static inline int __blk_mq_active_requests(struct blk_mq_hw_ctx *hctx)
329{
330 if (blk_mq_is_shared_tags(flags: hctx->flags))
331 return atomic_read(v: &hctx->queue->nr_active_requests_shared_tags);
332 return atomic_read(v: &hctx->nr_active);
333}
334static inline void __blk_mq_put_driver_tag(struct blk_mq_hw_ctx *hctx,
335 struct request *rq)
336{
337 blk_mq_dec_active_requests(hctx);
338 blk_mq_put_tag(tags: hctx->tags, ctx: rq->mq_ctx, tag: rq->tag);
339 rq->tag = BLK_MQ_NO_TAG;
340}
341
342static inline void blk_mq_put_driver_tag(struct request *rq)
343{
344 if (rq->tag == BLK_MQ_NO_TAG || rq->internal_tag == BLK_MQ_NO_TAG)
345 return;
346
347 __blk_mq_put_driver_tag(hctx: rq->mq_hctx, rq);
348}
349
350bool __blk_mq_alloc_driver_tag(struct request *rq);
351
352static inline bool blk_mq_get_driver_tag(struct request *rq)
353{
354 if (rq->tag == BLK_MQ_NO_TAG && !__blk_mq_alloc_driver_tag(rq))
355 return false;
356
357 return true;
358}
359
360static inline void blk_mq_clear_mq_map(struct blk_mq_queue_map *qmap)
361{
362 int cpu;
363
364 for_each_possible_cpu(cpu)
365 qmap->mq_map[cpu] = 0;
366}
367
368/*
369 * blk_mq_plug() - Get caller context plug
370 * @bio : the bio being submitted by the caller context
371 *
372 * Plugging, by design, may delay the insertion of BIOs into the elevator in
373 * order to increase BIO merging opportunities. This however can cause BIO
374 * insertion order to change from the order in which submit_bio() is being
375 * executed in the case of multiple contexts concurrently issuing BIOs to a
376 * device, even if these context are synchronized to tightly control BIO issuing
377 * order. While this is not a problem with regular block devices, this ordering
378 * change can cause write BIO failures with zoned block devices as these
379 * require sequential write patterns to zones. Prevent this from happening by
380 * ignoring the plug state of a BIO issuing context if it is for a zoned block
381 * device and the BIO to plug is a write operation.
382 *
383 * Return current->plug if the bio can be plugged and NULL otherwise
384 */
385static inline struct blk_plug *blk_mq_plug( struct bio *bio)
386{
387 /* Zoned block device write operation case: do not plug the BIO */
388 if (IS_ENABLED(CONFIG_BLK_DEV_ZONED) &&
389 bdev_op_is_zoned_write(bdev: bio->bi_bdev, op: bio_op(bio)))
390 return NULL;
391
392 /*
393 * For regular block devices or read operations, use the context plug
394 * which may be NULL if blk_start_plug() was not executed.
395 */
396 return current->plug;
397}
398
399/* Free all requests on the list */
400static inline void blk_mq_free_requests(struct list_head *list)
401{
402 while (!list_empty(head: list)) {
403 struct request *rq = list_entry_rq(list->next);
404
405 list_del_init(entry: &rq->queuelist);
406 blk_mq_free_request(rq);
407 }
408}
409
410/*
411 * For shared tag users, we track the number of currently active users
412 * and attempt to provide a fair share of the tag depth for each of them.
413 */
414static inline bool hctx_may_queue(struct blk_mq_hw_ctx *hctx,
415 struct sbitmap_queue *bt)
416{
417 unsigned int depth, users;
418
419 if (!hctx || !(hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED))
420 return true;
421
422 /*
423 * Don't try dividing an ant
424 */
425 if (bt->sb.depth == 1)
426 return true;
427
428 if (blk_mq_is_shared_tags(flags: hctx->flags)) {
429 struct request_queue *q = hctx->queue;
430
431 if (!test_bit(QUEUE_FLAG_HCTX_ACTIVE, &q->queue_flags))
432 return true;
433 } else {
434 if (!test_bit(BLK_MQ_S_TAG_ACTIVE, &hctx->state))
435 return true;
436 }
437
438 users = READ_ONCE(hctx->tags->active_queues);
439 if (!users)
440 return true;
441
442 /*
443 * Allow at least some tags
444 */
445 depth = max((bt->sb.depth + users - 1) / users, 4U);
446 return __blk_mq_active_requests(hctx) < depth;
447}
448
449/* run the code block in @dispatch_ops with rcu/srcu read lock held */
450#define __blk_mq_run_dispatch_ops(q, check_sleep, dispatch_ops) \
451do { \
452 if ((q)->tag_set->flags & BLK_MQ_F_BLOCKING) { \
453 struct blk_mq_tag_set *__tag_set = (q)->tag_set; \
454 int srcu_idx; \
455 \
456 might_sleep_if(check_sleep); \
457 srcu_idx = srcu_read_lock(__tag_set->srcu); \
458 (dispatch_ops); \
459 srcu_read_unlock(__tag_set->srcu, srcu_idx); \
460 } else { \
461 rcu_read_lock(); \
462 (dispatch_ops); \
463 rcu_read_unlock(); \
464 } \
465} while (0)
466
467#define blk_mq_run_dispatch_ops(q, dispatch_ops) \
468 __blk_mq_run_dispatch_ops(q, true, dispatch_ops) \
469
470#endif
471

source code of linux/block/blk-mq.h