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