Line data Source code
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 :
8 : struct blk_mq_tag_set;
9 :
10 : struct 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 : */
18 : struct 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 :
33 : enum {
34 : BLK_MQ_NO_TAG = -1U,
35 : BLK_MQ_TAG_MIN = 1,
36 : BLK_MQ_TAG_MAX = BLK_MQ_NO_TAG - 1,
37 : };
38 :
39 : typedef unsigned int __bitwise blk_insert_t;
40 : #define BLK_MQ_INSERT_AT_HEAD ((__force blk_insert_t)0x01)
41 :
42 : void blk_mq_submit_bio(struct bio *bio);
43 : int blk_mq_poll(struct request_queue *q, blk_qc_t cookie, struct io_comp_batch *iob,
44 : unsigned int flags);
45 : void blk_mq_exit_queue(struct request_queue *q);
46 : int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr);
47 : void blk_mq_wake_waiters(struct request_queue *q);
48 : bool blk_mq_dispatch_rq_list(struct blk_mq_hw_ctx *hctx, struct list_head *,
49 : unsigned int);
50 : void blk_mq_flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, struct list_head *list);
51 : struct request *blk_mq_dequeue_from_ctx(struct blk_mq_hw_ctx *hctx,
52 : struct blk_mq_ctx *start);
53 : void blk_mq_put_rq_ref(struct request *rq);
54 :
55 : /*
56 : * Internal helpers for allocating/freeing the request map
57 : */
58 : void blk_mq_free_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
59 : unsigned int hctx_idx);
60 : void blk_mq_free_rq_map(struct blk_mq_tags *tags);
61 : struct blk_mq_tags *blk_mq_alloc_map_and_rqs(struct blk_mq_tag_set *set,
62 : unsigned int hctx_idx, unsigned int depth);
63 : void 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 : */
70 : extern 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 : */
78 : static 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 0 : return xa_load(&q->hctx_table, q->tag_set->map[type].mq_map[cpu]);
83 : }
84 :
85 : static inline enum hctx_type blk_mq_get_hctx_type(blk_opf_t opf)
86 : {
87 0 : enum hctx_type type = HCTX_TYPE_DEFAULT;
88 :
89 : /*
90 : * The caller ensure that if REQ_POLLED, poll must be enabled.
91 : */
92 0 : if (opf & REQ_POLLED)
93 : type = HCTX_TYPE_POLL;
94 0 : else if ((opf & REQ_OP_MASK) == REQ_OP_READ)
95 0 : 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 : */
105 : static 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 0 : return ctx->hctxs[blk_mq_get_hctx_type(opf)];
110 : }
111 :
112 : /*
113 : * sysfs helpers
114 : */
115 : extern void blk_mq_sysfs_init(struct request_queue *q);
116 : extern void blk_mq_sysfs_deinit(struct request_queue *q);
117 : int blk_mq_sysfs_register(struct gendisk *disk);
118 : void blk_mq_sysfs_unregister(struct gendisk *disk);
119 : int blk_mq_sysfs_register_hctxs(struct request_queue *q);
120 : void blk_mq_sysfs_unregister_hctxs(struct request_queue *q);
121 : extern void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx);
122 : void blk_mq_free_plug_rqs(struct blk_plug *plug);
123 : void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule);
124 :
125 : void blk_mq_cancel_work_sync(struct request_queue *q);
126 :
127 : void blk_mq_release(struct request_queue *q);
128 :
129 : static inline struct blk_mq_ctx *__blk_mq_get_ctx(struct request_queue *q,
130 : unsigned int cpu)
131 : {
132 0 : 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 : */
141 : static inline struct blk_mq_ctx *blk_mq_get_ctx(struct request_queue *q)
142 : {
143 0 : return __blk_mq_get_ctx(q, raw_smp_processor_id());
144 : }
145 :
146 : struct 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 :
163 : struct blk_mq_tags *blk_mq_init_tags(unsigned int nr_tags,
164 : unsigned int reserved_tags, int node, int alloc_policy);
165 : void blk_mq_free_tags(struct blk_mq_tags *tags);
166 : int 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 :
170 : unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data);
171 : unsigned long blk_mq_get_tags(struct blk_mq_alloc_data *data, int nr_tags,
172 : unsigned int *offset);
173 : void blk_mq_put_tag(struct blk_mq_tags *tags, struct blk_mq_ctx *ctx,
174 : unsigned int tag);
175 : void blk_mq_put_tags(struct blk_mq_tags *tags, int *tag_array, int nr_tags);
176 : int blk_mq_tag_update_depth(struct blk_mq_hw_ctx *hctx,
177 : struct blk_mq_tags **tags, unsigned int depth, bool can_grow);
178 : void blk_mq_tag_resize_shared_tags(struct blk_mq_tag_set *set,
179 : unsigned int size);
180 : void blk_mq_tag_update_sched_shared_tags(struct request_queue *q);
181 :
182 : void blk_mq_tag_wakeup_all(struct blk_mq_tags *tags, bool);
183 : void blk_mq_queue_tag_busy_iter(struct request_queue *q, busy_tag_iter_fn *fn,
184 : void *priv);
185 : void blk_mq_all_tag_iter(struct blk_mq_tags *tags, busy_tag_iter_fn *fn,
186 : void *priv);
187 :
188 : static inline struct sbq_wait_state *bt_wait_ptr(struct sbitmap_queue *bt,
189 : struct blk_mq_hw_ctx *hctx)
190 : {
191 0 : if (!hctx)
192 0 : return &bt->ws[0];
193 0 : return sbq_wait_ptr(bt, &hctx->wait_index);
194 : }
195 :
196 : void __blk_mq_tag_busy(struct blk_mq_hw_ctx *);
197 : void __blk_mq_tag_idle(struct blk_mq_hw_ctx *);
198 :
199 : static inline void blk_mq_tag_busy(struct blk_mq_hw_ctx *hctx)
200 : {
201 0 : if (hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED)
202 0 : __blk_mq_tag_busy(hctx);
203 : }
204 :
205 : static inline void blk_mq_tag_idle(struct blk_mq_hw_ctx *hctx)
206 : {
207 0 : if (hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED)
208 0 : __blk_mq_tag_idle(hctx);
209 : }
210 :
211 : static 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 :
217 : static inline bool blk_mq_is_shared_tags(unsigned int flags)
218 : {
219 0 : return flags & BLK_MQ_F_TAG_HCTX_SHARED;
220 : }
221 :
222 : static inline struct blk_mq_tags *blk_mq_tags_from_data(struct blk_mq_alloc_data *data)
223 : {
224 0 : if (data->rq_flags & RQF_SCHED_TAGS)
225 0 : return data->hctx->sched_tags;
226 0 : return data->hctx->tags;
227 : }
228 :
229 : static inline bool blk_mq_hctx_stopped(struct blk_mq_hw_ctx *hctx)
230 : {
231 0 : return test_bit(BLK_MQ_S_STOPPED, &hctx->state);
232 : }
233 :
234 : static inline bool blk_mq_hw_queue_mapped(struct blk_mq_hw_ctx *hctx)
235 : {
236 0 : return hctx->nr_ctx && hctx->tags;
237 : }
238 :
239 : unsigned int blk_mq_in_flight(struct request_queue *q,
240 : struct block_device *part);
241 : void blk_mq_in_flight_rw(struct request_queue *q, struct block_device *part,
242 : unsigned int inflight[2]);
243 :
244 : static inline void blk_mq_put_dispatch_budget(struct request_queue *q,
245 : int budget_token)
246 : {
247 0 : if (q->mq_ops->put_budget)
248 0 : q->mq_ops->put_budget(q, budget_token);
249 : }
250 :
251 : static inline int blk_mq_get_dispatch_budget(struct request_queue *q)
252 : {
253 0 : if (q->mq_ops->get_budget)
254 0 : return q->mq_ops->get_budget(q);
255 : return 0;
256 : }
257 :
258 : static inline void blk_mq_set_rq_budget_token(struct request *rq, int token)
259 : {
260 : if (token < 0)
261 : return;
262 :
263 0 : if (rq->q->mq_ops->set_rq_budget_token)
264 0 : rq->q->mq_ops->set_rq_budget_token(rq, token);
265 : }
266 :
267 : static inline int blk_mq_get_rq_budget_token(struct request *rq)
268 : {
269 0 : if (rq->q->mq_ops->get_rq_budget_token)
270 0 : return rq->q->mq_ops->get_rq_budget_token(rq);
271 : return -1;
272 : }
273 :
274 : static inline void __blk_mq_inc_active_requests(struct blk_mq_hw_ctx *hctx)
275 : {
276 0 : if (blk_mq_is_shared_tags(hctx->flags))
277 0 : atomic_inc(&hctx->queue->nr_active_requests_shared_tags);
278 : else
279 0 : atomic_inc(&hctx->nr_active);
280 : }
281 :
282 : static inline void __blk_mq_sub_active_requests(struct blk_mq_hw_ctx *hctx,
283 : int val)
284 : {
285 0 : if (blk_mq_is_shared_tags(hctx->flags))
286 0 : atomic_sub(val, &hctx->queue->nr_active_requests_shared_tags);
287 : else
288 0 : atomic_sub(val, &hctx->nr_active);
289 : }
290 :
291 : static inline void __blk_mq_dec_active_requests(struct blk_mq_hw_ctx *hctx)
292 : {
293 : __blk_mq_sub_active_requests(hctx, 1);
294 : }
295 :
296 : static inline int __blk_mq_active_requests(struct blk_mq_hw_ctx *hctx)
297 : {
298 0 : if (blk_mq_is_shared_tags(hctx->flags))
299 0 : return atomic_read(&hctx->queue->nr_active_requests_shared_tags);
300 0 : return atomic_read(&hctx->nr_active);
301 : }
302 0 : static inline void __blk_mq_put_driver_tag(struct blk_mq_hw_ctx *hctx,
303 : struct request *rq)
304 : {
305 0 : blk_mq_put_tag(hctx->tags, rq->mq_ctx, rq->tag);
306 0 : rq->tag = BLK_MQ_NO_TAG;
307 :
308 0 : if (rq->rq_flags & RQF_MQ_INFLIGHT) {
309 0 : rq->rq_flags &= ~RQF_MQ_INFLIGHT;
310 : __blk_mq_dec_active_requests(hctx);
311 : }
312 0 : }
313 :
314 : static inline void blk_mq_put_driver_tag(struct request *rq)
315 : {
316 0 : if (rq->tag == BLK_MQ_NO_TAG || rq->internal_tag == BLK_MQ_NO_TAG)
317 : return;
318 :
319 0 : __blk_mq_put_driver_tag(rq->mq_hctx, rq);
320 : }
321 :
322 : bool __blk_mq_get_driver_tag(struct blk_mq_hw_ctx *hctx, struct request *rq);
323 :
324 0 : static inline bool blk_mq_get_driver_tag(struct request *rq)
325 : {
326 0 : struct blk_mq_hw_ctx *hctx = rq->mq_hctx;
327 :
328 0 : if (rq->tag != BLK_MQ_NO_TAG &&
329 0 : !(hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED)) {
330 0 : hctx->tags->rqs[rq->tag] = rq;
331 0 : return true;
332 : }
333 :
334 0 : return __blk_mq_get_driver_tag(hctx, rq);
335 : }
336 :
337 : static inline void blk_mq_clear_mq_map(struct blk_mq_queue_map *qmap)
338 : {
339 : int cpu;
340 :
341 0 : for_each_possible_cpu(cpu)
342 0 : qmap->mq_map[cpu] = 0;
343 : }
344 :
345 : /*
346 : * blk_mq_plug() - Get caller context plug
347 : * @bio : the bio being submitted by the caller context
348 : *
349 : * Plugging, by design, may delay the insertion of BIOs into the elevator in
350 : * order to increase BIO merging opportunities. This however can cause BIO
351 : * insertion order to change from the order in which submit_bio() is being
352 : * executed in the case of multiple contexts concurrently issuing BIOs to a
353 : * device, even if these context are synchronized to tightly control BIO issuing
354 : * order. While this is not a problem with regular block devices, this ordering
355 : * change can cause write BIO failures with zoned block devices as these
356 : * require sequential write patterns to zones. Prevent this from happening by
357 : * ignoring the plug state of a BIO issuing context if it is for a zoned block
358 : * device and the BIO to plug is a write operation.
359 : *
360 : * Return current->plug if the bio can be plugged and NULL otherwise
361 : */
362 : static inline struct blk_plug *blk_mq_plug( struct bio *bio)
363 : {
364 : /* Zoned block device write operation case: do not plug the BIO */
365 : if (IS_ENABLED(CONFIG_BLK_DEV_ZONED) &&
366 : bdev_op_is_zoned_write(bio->bi_bdev, bio_op(bio)))
367 : return NULL;
368 :
369 : /*
370 : * For regular block devices or read operations, use the context plug
371 : * which may be NULL if blk_start_plug() was not executed.
372 : */
373 0 : return current->plug;
374 : }
375 :
376 : /* Free all requests on the list */
377 0 : static inline void blk_mq_free_requests(struct list_head *list)
378 : {
379 0 : while (!list_empty(list)) {
380 0 : struct request *rq = list_entry_rq(list->next);
381 :
382 0 : list_del_init(&rq->queuelist);
383 0 : blk_mq_free_request(rq);
384 : }
385 0 : }
386 :
387 : /*
388 : * For shared tag users, we track the number of currently active users
389 : * and attempt to provide a fair share of the tag depth for each of them.
390 : */
391 0 : static inline bool hctx_may_queue(struct blk_mq_hw_ctx *hctx,
392 : struct sbitmap_queue *bt)
393 : {
394 : unsigned int depth, users;
395 :
396 0 : if (!hctx || !(hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED))
397 : return true;
398 :
399 : /*
400 : * Don't try dividing an ant
401 : */
402 0 : if (bt->sb.depth == 1)
403 : return true;
404 :
405 0 : if (blk_mq_is_shared_tags(hctx->flags)) {
406 0 : struct request_queue *q = hctx->queue;
407 :
408 0 : if (!test_bit(QUEUE_FLAG_HCTX_ACTIVE, &q->queue_flags))
409 : return true;
410 : } else {
411 0 : if (!test_bit(BLK_MQ_S_TAG_ACTIVE, &hctx->state))
412 : return true;
413 : }
414 :
415 0 : users = READ_ONCE(hctx->tags->active_queues);
416 0 : if (!users)
417 : return true;
418 :
419 : /*
420 : * Allow at least some tags
421 : */
422 0 : depth = max((bt->sb.depth + users - 1) / users, 4U);
423 0 : return __blk_mq_active_requests(hctx) < depth;
424 : }
425 :
426 : /* run the code block in @dispatch_ops with rcu/srcu read lock held */
427 : #define __blk_mq_run_dispatch_ops(q, check_sleep, dispatch_ops) \
428 : do { \
429 : if ((q)->tag_set->flags & BLK_MQ_F_BLOCKING) { \
430 : struct blk_mq_tag_set *__tag_set = (q)->tag_set; \
431 : int srcu_idx; \
432 : \
433 : might_sleep_if(check_sleep); \
434 : srcu_idx = srcu_read_lock(__tag_set->srcu); \
435 : (dispatch_ops); \
436 : srcu_read_unlock(__tag_set->srcu, srcu_idx); \
437 : } else { \
438 : rcu_read_lock(); \
439 : (dispatch_ops); \
440 : rcu_read_unlock(); \
441 : } \
442 : } while (0)
443 :
444 : #define blk_mq_run_dispatch_ops(q, dispatch_ops) \
445 : __blk_mq_run_dispatch_ops(q, true, dispatch_ops) \
446 :
447 : #endif
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