blob: c79126e110308e8b1ea4b322506a425ceeb3085c [file] [log] [blame]
Jens Axboe320ae512013-10-24 09:20:05 +01001#include <linux/kernel.h>
2#include <linux/module.h>
3#include <linux/backing-dev.h>
4#include <linux/bio.h>
5#include <linux/blkdev.h>
6#include <linux/mm.h>
7#include <linux/init.h>
8#include <linux/slab.h>
9#include <linux/workqueue.h>
10#include <linux/smp.h>
11#include <linux/llist.h>
12#include <linux/list_sort.h>
13#include <linux/cpu.h>
14#include <linux/cache.h>
15#include <linux/sched/sysctl.h>
16#include <linux/delay.h>
17
18#include <trace/events/block.h>
19
20#include <linux/blk-mq.h>
21#include "blk.h"
22#include "blk-mq.h"
23#include "blk-mq-tag.h"
24
25static DEFINE_MUTEX(all_q_mutex);
26static LIST_HEAD(all_q_list);
27
28static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx);
29
30DEFINE_PER_CPU(struct llist_head, ipi_lists);
31
32static struct blk_mq_ctx *__blk_mq_get_ctx(struct request_queue *q,
33 unsigned int cpu)
34{
35 return per_cpu_ptr(q->queue_ctx, cpu);
36}
37
38/*
39 * This assumes per-cpu software queueing queues. They could be per-node
40 * as well, for instance. For now this is hardcoded as-is. Note that we don't
41 * care about preemption, since we know the ctx's are persistent. This does
42 * mean that we can't rely on ctx always matching the currently running CPU.
43 */
44static struct blk_mq_ctx *blk_mq_get_ctx(struct request_queue *q)
45{
46 return __blk_mq_get_ctx(q, get_cpu());
47}
48
49static void blk_mq_put_ctx(struct blk_mq_ctx *ctx)
50{
51 put_cpu();
52}
53
54/*
55 * Check if any of the ctx's have pending work in this hardware queue
56 */
57static bool blk_mq_hctx_has_pending(struct blk_mq_hw_ctx *hctx)
58{
59 unsigned int i;
60
61 for (i = 0; i < hctx->nr_ctx_map; i++)
62 if (hctx->ctx_map[i])
63 return true;
64
65 return false;
66}
67
68/*
69 * Mark this ctx as having pending work in this hardware queue
70 */
71static void blk_mq_hctx_mark_pending(struct blk_mq_hw_ctx *hctx,
72 struct blk_mq_ctx *ctx)
73{
74 if (!test_bit(ctx->index_hw, hctx->ctx_map))
75 set_bit(ctx->index_hw, hctx->ctx_map);
76}
77
78static struct request *blk_mq_alloc_rq(struct blk_mq_hw_ctx *hctx, gfp_t gfp,
79 bool reserved)
80{
81 struct request *rq;
82 unsigned int tag;
83
84 tag = blk_mq_get_tag(hctx->tags, gfp, reserved);
85 if (tag != BLK_MQ_TAG_FAIL) {
86 rq = hctx->rqs[tag];
87 rq->tag = tag;
88
89 return rq;
90 }
91
92 return NULL;
93}
94
95static int blk_mq_queue_enter(struct request_queue *q)
96{
97 int ret;
98
99 __percpu_counter_add(&q->mq_usage_counter, 1, 1000000);
100 smp_wmb();
101 /* we have problems to freeze the queue if it's initializing */
102 if (!blk_queue_bypass(q) || !blk_queue_init_done(q))
103 return 0;
104
105 __percpu_counter_add(&q->mq_usage_counter, -1, 1000000);
106
107 spin_lock_irq(q->queue_lock);
108 ret = wait_event_interruptible_lock_irq(q->mq_freeze_wq,
109 !blk_queue_bypass(q), *q->queue_lock);
110 /* inc usage with lock hold to avoid freeze_queue runs here */
111 if (!ret)
112 __percpu_counter_add(&q->mq_usage_counter, 1, 1000000);
113 spin_unlock_irq(q->queue_lock);
114
115 return ret;
116}
117
118static void blk_mq_queue_exit(struct request_queue *q)
119{
120 __percpu_counter_add(&q->mq_usage_counter, -1, 1000000);
121}
122
123/*
124 * Guarantee no request is in use, so we can change any data structure of
125 * the queue afterward.
126 */
127static void blk_mq_freeze_queue(struct request_queue *q)
128{
129 bool drain;
130
131 spin_lock_irq(q->queue_lock);
132 drain = !q->bypass_depth++;
133 queue_flag_set(QUEUE_FLAG_BYPASS, q);
134 spin_unlock_irq(q->queue_lock);
135
136 if (!drain)
137 return;
138
139 while (true) {
140 s64 count;
141
142 spin_lock_irq(q->queue_lock);
143 count = percpu_counter_sum(&q->mq_usage_counter);
144 spin_unlock_irq(q->queue_lock);
145
146 if (count == 0)
147 break;
148 blk_mq_run_queues(q, false);
149 msleep(10);
150 }
151}
152
153static void blk_mq_unfreeze_queue(struct request_queue *q)
154{
155 bool wake = false;
156
157 spin_lock_irq(q->queue_lock);
158 if (!--q->bypass_depth) {
159 queue_flag_clear(QUEUE_FLAG_BYPASS, q);
160 wake = true;
161 }
162 WARN_ON_ONCE(q->bypass_depth < 0);
163 spin_unlock_irq(q->queue_lock);
164 if (wake)
165 wake_up_all(&q->mq_freeze_wq);
166}
167
168bool blk_mq_can_queue(struct blk_mq_hw_ctx *hctx)
169{
170 return blk_mq_has_free_tags(hctx->tags);
171}
172EXPORT_SYMBOL(blk_mq_can_queue);
173
Jens Axboe94eddfb2013-11-19 09:25:07 -0700174static void blk_mq_rq_ctx_init(struct request_queue *q, struct blk_mq_ctx *ctx,
175 struct request *rq, unsigned int rw_flags)
Jens Axboe320ae512013-10-24 09:20:05 +0100176{
Jens Axboe94eddfb2013-11-19 09:25:07 -0700177 if (blk_queue_io_stat(q))
178 rw_flags |= REQ_IO_STAT;
179
Jens Axboe320ae512013-10-24 09:20:05 +0100180 rq->mq_ctx = ctx;
181 rq->cmd_flags = rw_flags;
182 ctx->rq_dispatched[rw_is_sync(rw_flags)]++;
183}
184
185static struct request *__blk_mq_alloc_request(struct blk_mq_hw_ctx *hctx,
186 gfp_t gfp, bool reserved)
187{
188 return blk_mq_alloc_rq(hctx, gfp, reserved);
189}
190
191static struct request *blk_mq_alloc_request_pinned(struct request_queue *q,
192 int rw, gfp_t gfp,
193 bool reserved)
194{
195 struct request *rq;
196
197 do {
198 struct blk_mq_ctx *ctx = blk_mq_get_ctx(q);
199 struct blk_mq_hw_ctx *hctx = q->mq_ops->map_queue(q, ctx->cpu);
200
201 rq = __blk_mq_alloc_request(hctx, gfp & ~__GFP_WAIT, reserved);
202 if (rq) {
Jens Axboe94eddfb2013-11-19 09:25:07 -0700203 blk_mq_rq_ctx_init(q, ctx, rq, rw);
Jens Axboe320ae512013-10-24 09:20:05 +0100204 break;
Jeff Moyer959a35f2013-12-03 14:23:00 -0700205 }
Jens Axboe320ae512013-10-24 09:20:05 +0100206
207 blk_mq_put_ctx(ctx);
Jeff Moyer959a35f2013-12-03 14:23:00 -0700208 if (!(gfp & __GFP_WAIT))
209 break;
210
Jens Axboe320ae512013-10-24 09:20:05 +0100211 __blk_mq_run_hw_queue(hctx);
212 blk_mq_wait_for_tags(hctx->tags);
213 } while (1);
214
215 return rq;
216}
217
Christoph Hellwig3228f482013-10-28 13:33:58 -0600218struct request *blk_mq_alloc_request(struct request_queue *q, int rw,
219 gfp_t gfp, bool reserved)
Jens Axboe320ae512013-10-24 09:20:05 +0100220{
221 struct request *rq;
222
223 if (blk_mq_queue_enter(q))
224 return NULL;
225
Christoph Hellwig3228f482013-10-28 13:33:58 -0600226 rq = blk_mq_alloc_request_pinned(q, rw, gfp, reserved);
Jeff Moyer959a35f2013-12-03 14:23:00 -0700227 if (rq)
228 blk_mq_put_ctx(rq->mq_ctx);
Jens Axboe320ae512013-10-24 09:20:05 +0100229 return rq;
230}
231
232struct request *blk_mq_alloc_reserved_request(struct request_queue *q, int rw,
233 gfp_t gfp)
234{
235 struct request *rq;
236
237 if (blk_mq_queue_enter(q))
238 return NULL;
239
240 rq = blk_mq_alloc_request_pinned(q, rw, gfp, true);
Jeff Moyer959a35f2013-12-03 14:23:00 -0700241 if (rq)
242 blk_mq_put_ctx(rq->mq_ctx);
Jens Axboe320ae512013-10-24 09:20:05 +0100243 return rq;
244}
245EXPORT_SYMBOL(blk_mq_alloc_reserved_request);
246
247/*
248 * Re-init and set pdu, if we have it
249 */
250static void blk_mq_rq_init(struct blk_mq_hw_ctx *hctx, struct request *rq)
251{
252 blk_rq_init(hctx->queue, rq);
253
254 if (hctx->cmd_size)
255 rq->special = blk_mq_rq_to_pdu(rq);
256}
257
258static void __blk_mq_free_request(struct blk_mq_hw_ctx *hctx,
259 struct blk_mq_ctx *ctx, struct request *rq)
260{
261 const int tag = rq->tag;
262 struct request_queue *q = rq->q;
263
264 blk_mq_rq_init(hctx, rq);
265 blk_mq_put_tag(hctx->tags, tag);
266
267 blk_mq_queue_exit(q);
268}
269
270void blk_mq_free_request(struct request *rq)
271{
272 struct blk_mq_ctx *ctx = rq->mq_ctx;
273 struct blk_mq_hw_ctx *hctx;
274 struct request_queue *q = rq->q;
275
276 ctx->rq_completed[rq_is_sync(rq)]++;
277
278 hctx = q->mq_ops->map_queue(q, ctx->cpu);
279 __blk_mq_free_request(hctx, ctx, rq);
280}
281
282static void blk_mq_bio_endio(struct request *rq, struct bio *bio, int error)
283{
284 if (error)
285 clear_bit(BIO_UPTODATE, &bio->bi_flags);
286 else if (!test_bit(BIO_UPTODATE, &bio->bi_flags))
287 error = -EIO;
288
289 if (unlikely(rq->cmd_flags & REQ_QUIET))
290 set_bit(BIO_QUIET, &bio->bi_flags);
291
292 /* don't actually finish bio if it's part of flush sequence */
293 if (!(rq->cmd_flags & REQ_FLUSH_SEQ))
294 bio_endio(bio, error);
295}
296
297void blk_mq_complete_request(struct request *rq, int error)
298{
299 struct bio *bio = rq->bio;
300 unsigned int bytes = 0;
301
302 trace_block_rq_complete(rq->q, rq);
303
304 while (bio) {
305 struct bio *next = bio->bi_next;
306
307 bio->bi_next = NULL;
308 bytes += bio->bi_size;
309 blk_mq_bio_endio(rq, bio, error);
310 bio = next;
311 }
312
313 blk_account_io_completion(rq, bytes);
314
Ming Lei0d11e6a2013-12-05 10:50:39 -0700315 blk_account_io_done(rq);
316
Jens Axboe320ae512013-10-24 09:20:05 +0100317 if (rq->end_io)
318 rq->end_io(rq, error);
319 else
320 blk_mq_free_request(rq);
Jens Axboe320ae512013-10-24 09:20:05 +0100321}
322
323void __blk_mq_end_io(struct request *rq, int error)
324{
325 if (!blk_mark_rq_complete(rq))
326 blk_mq_complete_request(rq, error);
327}
328
Christoph Hellwig0a06ff02013-11-14 14:32:07 -0800329#if defined(CONFIG_SMP)
Jens Axboe320ae512013-10-24 09:20:05 +0100330
331/*
332 * Called with interrupts disabled.
333 */
334static void ipi_end_io(void *data)
335{
336 struct llist_head *list = &per_cpu(ipi_lists, smp_processor_id());
337 struct llist_node *entry, *next;
338 struct request *rq;
339
340 entry = llist_del_all(list);
341
342 while (entry) {
343 next = entry->next;
344 rq = llist_entry(entry, struct request, ll_list);
345 __blk_mq_end_io(rq, rq->errors);
346 entry = next;
347 }
348}
349
350static int ipi_remote_cpu(struct blk_mq_ctx *ctx, const int cpu,
351 struct request *rq, const int error)
352{
353 struct call_single_data *data = &rq->csd;
354
355 rq->errors = error;
356 rq->ll_list.next = NULL;
357
358 /*
359 * If the list is non-empty, an existing IPI must already
360 * be "in flight". If that is the case, we need not schedule
361 * a new one.
362 */
363 if (llist_add(&rq->ll_list, &per_cpu(ipi_lists, ctx->cpu))) {
364 data->func = ipi_end_io;
365 data->flags = 0;
366 __smp_call_function_single(ctx->cpu, data, 0);
367 }
368
369 return true;
370}
Christoph Hellwig0a06ff02013-11-14 14:32:07 -0800371#else /* CONFIG_SMP */
Jens Axboe320ae512013-10-24 09:20:05 +0100372static int ipi_remote_cpu(struct blk_mq_ctx *ctx, const int cpu,
373 struct request *rq, const int error)
374{
375 return false;
376}
377#endif
378
379/*
380 * End IO on this request on a multiqueue enabled driver. We'll either do
381 * it directly inline, or punt to a local IPI handler on the matching
382 * remote CPU.
383 */
384void blk_mq_end_io(struct request *rq, int error)
385{
386 struct blk_mq_ctx *ctx = rq->mq_ctx;
387 int cpu;
388
389 if (!ctx->ipi_redirect)
390 return __blk_mq_end_io(rq, error);
391
392 cpu = get_cpu();
393
394 if (cpu == ctx->cpu || !cpu_online(ctx->cpu) ||
395 !ipi_remote_cpu(ctx, cpu, rq, error))
396 __blk_mq_end_io(rq, error);
397
398 put_cpu();
399}
400EXPORT_SYMBOL(blk_mq_end_io);
401
402static void blk_mq_start_request(struct request *rq)
403{
404 struct request_queue *q = rq->q;
405
406 trace_block_rq_issue(q, rq);
407
408 /*
409 * Just mark start time and set the started bit. Due to memory
410 * ordering, we know we'll see the correct deadline as long as
411 * REQ_ATOMIC_STARTED is seen.
412 */
413 rq->deadline = jiffies + q->rq_timeout;
414 set_bit(REQ_ATOM_STARTED, &rq->atomic_flags);
415}
416
417static void blk_mq_requeue_request(struct request *rq)
418{
419 struct request_queue *q = rq->q;
420
421 trace_block_rq_requeue(q, rq);
422 clear_bit(REQ_ATOM_STARTED, &rq->atomic_flags);
423}
424
425struct blk_mq_timeout_data {
426 struct blk_mq_hw_ctx *hctx;
427 unsigned long *next;
428 unsigned int *next_set;
429};
430
431static void blk_mq_timeout_check(void *__data, unsigned long *free_tags)
432{
433 struct blk_mq_timeout_data *data = __data;
434 struct blk_mq_hw_ctx *hctx = data->hctx;
435 unsigned int tag;
436
437 /* It may not be in flight yet (this is where
438 * the REQ_ATOMIC_STARTED flag comes in). The requests are
439 * statically allocated, so we know it's always safe to access the
440 * memory associated with a bit offset into ->rqs[].
441 */
442 tag = 0;
443 do {
444 struct request *rq;
445
446 tag = find_next_zero_bit(free_tags, hctx->queue_depth, tag);
447 if (tag >= hctx->queue_depth)
448 break;
449
450 rq = hctx->rqs[tag++];
451
452 if (!test_bit(REQ_ATOM_STARTED, &rq->atomic_flags))
453 continue;
454
455 blk_rq_check_expired(rq, data->next, data->next_set);
456 } while (1);
457}
458
459static void blk_mq_hw_ctx_check_timeout(struct blk_mq_hw_ctx *hctx,
460 unsigned long *next,
461 unsigned int *next_set)
462{
463 struct blk_mq_timeout_data data = {
464 .hctx = hctx,
465 .next = next,
466 .next_set = next_set,
467 };
468
469 /*
470 * Ask the tagging code to iterate busy requests, so we can
471 * check them for timeout.
472 */
473 blk_mq_tag_busy_iter(hctx->tags, blk_mq_timeout_check, &data);
474}
475
476static void blk_mq_rq_timer(unsigned long data)
477{
478 struct request_queue *q = (struct request_queue *) data;
479 struct blk_mq_hw_ctx *hctx;
480 unsigned long next = 0;
481 int i, next_set = 0;
482
483 queue_for_each_hw_ctx(q, hctx, i)
484 blk_mq_hw_ctx_check_timeout(hctx, &next, &next_set);
485
486 if (next_set)
487 mod_timer(&q->timeout, round_jiffies_up(next));
488}
489
490/*
491 * Reverse check our software queue for entries that we could potentially
492 * merge with. Currently includes a hand-wavy stop count of 8, to not spend
493 * too much time checking for merges.
494 */
495static bool blk_mq_attempt_merge(struct request_queue *q,
496 struct blk_mq_ctx *ctx, struct bio *bio)
497{
498 struct request *rq;
499 int checked = 8;
500
501 list_for_each_entry_reverse(rq, &ctx->rq_list, queuelist) {
502 int el_ret;
503
504 if (!checked--)
505 break;
506
507 if (!blk_rq_merge_ok(rq, bio))
508 continue;
509
510 el_ret = blk_try_merge(rq, bio);
511 if (el_ret == ELEVATOR_BACK_MERGE) {
512 if (bio_attempt_back_merge(q, rq, bio)) {
513 ctx->rq_merged++;
514 return true;
515 }
516 break;
517 } else if (el_ret == ELEVATOR_FRONT_MERGE) {
518 if (bio_attempt_front_merge(q, rq, bio)) {
519 ctx->rq_merged++;
520 return true;
521 }
522 break;
523 }
524 }
525
526 return false;
527}
528
529void blk_mq_add_timer(struct request *rq)
530{
531 __blk_add_timer(rq, NULL);
532}
533
534/*
535 * Run this hardware queue, pulling any software queues mapped to it in.
536 * Note that this function currently has various problems around ordering
537 * of IO. In particular, we'd like FIFO behaviour on handling existing
538 * items on the hctx->dispatch list. Ignore that for now.
539 */
540static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx)
541{
542 struct request_queue *q = hctx->queue;
543 struct blk_mq_ctx *ctx;
544 struct request *rq;
545 LIST_HEAD(rq_list);
546 int bit, queued;
547
548 if (unlikely(test_bit(BLK_MQ_S_STOPPED, &hctx->flags)))
549 return;
550
551 hctx->run++;
552
553 /*
554 * Touch any software queue that has pending entries.
555 */
556 for_each_set_bit(bit, hctx->ctx_map, hctx->nr_ctx) {
557 clear_bit(bit, hctx->ctx_map);
558 ctx = hctx->ctxs[bit];
559 BUG_ON(bit != ctx->index_hw);
560
561 spin_lock(&ctx->lock);
562 list_splice_tail_init(&ctx->rq_list, &rq_list);
563 spin_unlock(&ctx->lock);
564 }
565
566 /*
567 * If we have previous entries on our dispatch list, grab them
568 * and stuff them at the front for more fair dispatch.
569 */
570 if (!list_empty_careful(&hctx->dispatch)) {
571 spin_lock(&hctx->lock);
572 if (!list_empty(&hctx->dispatch))
573 list_splice_init(&hctx->dispatch, &rq_list);
574 spin_unlock(&hctx->lock);
575 }
576
577 /*
578 * Delete and return all entries from our dispatch list
579 */
580 queued = 0;
581
582 /*
583 * Now process all the entries, sending them to the driver.
584 */
585 while (!list_empty(&rq_list)) {
586 int ret;
587
588 rq = list_first_entry(&rq_list, struct request, queuelist);
589 list_del_init(&rq->queuelist);
590 blk_mq_start_request(rq);
591
592 /*
593 * Last request in the series. Flag it as such, this
594 * enables drivers to know when IO should be kicked off,
595 * if they don't do it on a per-request basis.
596 *
597 * Note: the flag isn't the only condition drivers
598 * should do kick off. If drive is busy, the last
599 * request might not have the bit set.
600 */
601 if (list_empty(&rq_list))
602 rq->cmd_flags |= REQ_END;
603
604 ret = q->mq_ops->queue_rq(hctx, rq);
605 switch (ret) {
606 case BLK_MQ_RQ_QUEUE_OK:
607 queued++;
608 continue;
609 case BLK_MQ_RQ_QUEUE_BUSY:
610 /*
611 * FIXME: we should have a mechanism to stop the queue
612 * like blk_stop_queue, otherwise we will waste cpu
613 * time
614 */
615 list_add(&rq->queuelist, &rq_list);
616 blk_mq_requeue_request(rq);
617 break;
618 default:
619 pr_err("blk-mq: bad return on queue: %d\n", ret);
620 rq->errors = -EIO;
621 case BLK_MQ_RQ_QUEUE_ERROR:
622 blk_mq_end_io(rq, rq->errors);
623 break;
624 }
625
626 if (ret == BLK_MQ_RQ_QUEUE_BUSY)
627 break;
628 }
629
630 if (!queued)
631 hctx->dispatched[0]++;
632 else if (queued < (1 << (BLK_MQ_MAX_DISPATCH_ORDER - 1)))
633 hctx->dispatched[ilog2(queued) + 1]++;
634
635 /*
636 * Any items that need requeuing? Stuff them into hctx->dispatch,
637 * that is where we will continue on next queue run.
638 */
639 if (!list_empty(&rq_list)) {
640 spin_lock(&hctx->lock);
641 list_splice(&rq_list, &hctx->dispatch);
642 spin_unlock(&hctx->lock);
643 }
644}
645
646void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async)
647{
648 if (unlikely(test_bit(BLK_MQ_S_STOPPED, &hctx->flags)))
649 return;
650
651 if (!async)
652 __blk_mq_run_hw_queue(hctx);
653 else {
654 struct request_queue *q = hctx->queue;
655
656 kblockd_schedule_delayed_work(q, &hctx->delayed_work, 0);
657 }
658}
659
660void blk_mq_run_queues(struct request_queue *q, bool async)
661{
662 struct blk_mq_hw_ctx *hctx;
663 int i;
664
665 queue_for_each_hw_ctx(q, hctx, i) {
666 if ((!blk_mq_hctx_has_pending(hctx) &&
667 list_empty_careful(&hctx->dispatch)) ||
668 test_bit(BLK_MQ_S_STOPPED, &hctx->flags))
669 continue;
670
671 blk_mq_run_hw_queue(hctx, async);
672 }
673}
674EXPORT_SYMBOL(blk_mq_run_queues);
675
676void blk_mq_stop_hw_queue(struct blk_mq_hw_ctx *hctx)
677{
678 cancel_delayed_work(&hctx->delayed_work);
679 set_bit(BLK_MQ_S_STOPPED, &hctx->state);
680}
681EXPORT_SYMBOL(blk_mq_stop_hw_queue);
682
Christoph Hellwig280d45f2013-10-25 14:45:58 +0100683void blk_mq_stop_hw_queues(struct request_queue *q)
684{
685 struct blk_mq_hw_ctx *hctx;
686 int i;
687
688 queue_for_each_hw_ctx(q, hctx, i)
689 blk_mq_stop_hw_queue(hctx);
690}
691EXPORT_SYMBOL(blk_mq_stop_hw_queues);
692
Jens Axboe320ae512013-10-24 09:20:05 +0100693void blk_mq_start_hw_queue(struct blk_mq_hw_ctx *hctx)
694{
695 clear_bit(BLK_MQ_S_STOPPED, &hctx->state);
696 __blk_mq_run_hw_queue(hctx);
697}
698EXPORT_SYMBOL(blk_mq_start_hw_queue);
699
700void blk_mq_start_stopped_hw_queues(struct request_queue *q)
701{
702 struct blk_mq_hw_ctx *hctx;
703 int i;
704
705 queue_for_each_hw_ctx(q, hctx, i) {
706 if (!test_bit(BLK_MQ_S_STOPPED, &hctx->state))
707 continue;
708
709 clear_bit(BLK_MQ_S_STOPPED, &hctx->state);
710 blk_mq_run_hw_queue(hctx, true);
711 }
712}
713EXPORT_SYMBOL(blk_mq_start_stopped_hw_queues);
714
715static void blk_mq_work_fn(struct work_struct *work)
716{
717 struct blk_mq_hw_ctx *hctx;
718
719 hctx = container_of(work, struct blk_mq_hw_ctx, delayed_work.work);
720 __blk_mq_run_hw_queue(hctx);
721}
722
723static void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx,
724 struct request *rq)
725{
726 struct blk_mq_ctx *ctx = rq->mq_ctx;
727
Jens Axboe01b983c2013-11-19 18:59:10 -0700728 trace_block_rq_insert(hctx->queue, rq);
729
Jens Axboe320ae512013-10-24 09:20:05 +0100730 list_add_tail(&rq->queuelist, &ctx->rq_list);
731 blk_mq_hctx_mark_pending(hctx, ctx);
732
733 /*
734 * We do this early, to ensure we are on the right CPU.
735 */
736 blk_mq_add_timer(rq);
737}
738
739void blk_mq_insert_request(struct request_queue *q, struct request *rq,
740 bool run_queue)
741{
742 struct blk_mq_hw_ctx *hctx;
743 struct blk_mq_ctx *ctx, *current_ctx;
744
745 ctx = rq->mq_ctx;
746 hctx = q->mq_ops->map_queue(q, ctx->cpu);
747
748 if (rq->cmd_flags & (REQ_FLUSH | REQ_FUA)) {
749 blk_insert_flush(rq);
750 } else {
751 current_ctx = blk_mq_get_ctx(q);
752
753 if (!cpu_online(ctx->cpu)) {
754 ctx = current_ctx;
755 hctx = q->mq_ops->map_queue(q, ctx->cpu);
756 rq->mq_ctx = ctx;
757 }
758 spin_lock(&ctx->lock);
759 __blk_mq_insert_request(hctx, rq);
760 spin_unlock(&ctx->lock);
761
762 blk_mq_put_ctx(current_ctx);
763 }
764
765 if (run_queue)
766 __blk_mq_run_hw_queue(hctx);
767}
768EXPORT_SYMBOL(blk_mq_insert_request);
769
770/*
771 * This is a special version of blk_mq_insert_request to bypass FLUSH request
772 * check. Should only be used internally.
773 */
774void blk_mq_run_request(struct request *rq, bool run_queue, bool async)
775{
776 struct request_queue *q = rq->q;
777 struct blk_mq_hw_ctx *hctx;
778 struct blk_mq_ctx *ctx, *current_ctx;
779
780 current_ctx = blk_mq_get_ctx(q);
781
782 ctx = rq->mq_ctx;
783 if (!cpu_online(ctx->cpu)) {
784 ctx = current_ctx;
785 rq->mq_ctx = ctx;
786 }
787 hctx = q->mq_ops->map_queue(q, ctx->cpu);
788
789 /* ctx->cpu might be offline */
790 spin_lock(&ctx->lock);
791 __blk_mq_insert_request(hctx, rq);
792 spin_unlock(&ctx->lock);
793
794 blk_mq_put_ctx(current_ctx);
795
796 if (run_queue)
797 blk_mq_run_hw_queue(hctx, async);
798}
799
800static void blk_mq_insert_requests(struct request_queue *q,
801 struct blk_mq_ctx *ctx,
802 struct list_head *list,
803 int depth,
804 bool from_schedule)
805
806{
807 struct blk_mq_hw_ctx *hctx;
808 struct blk_mq_ctx *current_ctx;
809
810 trace_block_unplug(q, depth, !from_schedule);
811
812 current_ctx = blk_mq_get_ctx(q);
813
814 if (!cpu_online(ctx->cpu))
815 ctx = current_ctx;
816 hctx = q->mq_ops->map_queue(q, ctx->cpu);
817
818 /*
819 * preemption doesn't flush plug list, so it's possible ctx->cpu is
820 * offline now
821 */
822 spin_lock(&ctx->lock);
823 while (!list_empty(list)) {
824 struct request *rq;
825
826 rq = list_first_entry(list, struct request, queuelist);
827 list_del_init(&rq->queuelist);
828 rq->mq_ctx = ctx;
829 __blk_mq_insert_request(hctx, rq);
830 }
831 spin_unlock(&ctx->lock);
832
833 blk_mq_put_ctx(current_ctx);
834
835 blk_mq_run_hw_queue(hctx, from_schedule);
836}
837
838static int plug_ctx_cmp(void *priv, struct list_head *a, struct list_head *b)
839{
840 struct request *rqa = container_of(a, struct request, queuelist);
841 struct request *rqb = container_of(b, struct request, queuelist);
842
843 return !(rqa->mq_ctx < rqb->mq_ctx ||
844 (rqa->mq_ctx == rqb->mq_ctx &&
845 blk_rq_pos(rqa) < blk_rq_pos(rqb)));
846}
847
848void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule)
849{
850 struct blk_mq_ctx *this_ctx;
851 struct request_queue *this_q;
852 struct request *rq;
853 LIST_HEAD(list);
854 LIST_HEAD(ctx_list);
855 unsigned int depth;
856
857 list_splice_init(&plug->mq_list, &list);
858
859 list_sort(NULL, &list, plug_ctx_cmp);
860
861 this_q = NULL;
862 this_ctx = NULL;
863 depth = 0;
864
865 while (!list_empty(&list)) {
866 rq = list_entry_rq(list.next);
867 list_del_init(&rq->queuelist);
868 BUG_ON(!rq->q);
869 if (rq->mq_ctx != this_ctx) {
870 if (this_ctx) {
871 blk_mq_insert_requests(this_q, this_ctx,
872 &ctx_list, depth,
873 from_schedule);
874 }
875
876 this_ctx = rq->mq_ctx;
877 this_q = rq->q;
878 depth = 0;
879 }
880
881 depth++;
882 list_add_tail(&rq->queuelist, &ctx_list);
883 }
884
885 /*
886 * If 'this_ctx' is set, we know we have entries to complete
887 * on 'ctx_list'. Do those.
888 */
889 if (this_ctx) {
890 blk_mq_insert_requests(this_q, this_ctx, &ctx_list, depth,
891 from_schedule);
892 }
893}
894
895static void blk_mq_bio_to_request(struct request *rq, struct bio *bio)
896{
897 init_request_from_bio(rq, bio);
898 blk_account_io_start(rq, 1);
899}
900
901static void blk_mq_make_request(struct request_queue *q, struct bio *bio)
902{
903 struct blk_mq_hw_ctx *hctx;
904 struct blk_mq_ctx *ctx;
905 const int is_sync = rw_is_sync(bio->bi_rw);
906 const int is_flush_fua = bio->bi_rw & (REQ_FLUSH | REQ_FUA);
907 int rw = bio_data_dir(bio);
908 struct request *rq;
909 unsigned int use_plug, request_count = 0;
910
911 /*
912 * If we have multiple hardware queues, just go directly to
913 * one of those for sync IO.
914 */
915 use_plug = !is_flush_fua && ((q->nr_hw_queues == 1) || !is_sync);
916
917 blk_queue_bounce(q, &bio);
918
919 if (use_plug && blk_attempt_plug_merge(q, bio, &request_count))
920 return;
921
922 if (blk_mq_queue_enter(q)) {
923 bio_endio(bio, -EIO);
924 return;
925 }
926
927 ctx = blk_mq_get_ctx(q);
928 hctx = q->mq_ops->map_queue(q, ctx->cpu);
929
930 trace_block_getrq(q, bio, rw);
931 rq = __blk_mq_alloc_request(hctx, GFP_ATOMIC, false);
932 if (likely(rq))
Jens Axboe94eddfb2013-11-19 09:25:07 -0700933 blk_mq_rq_ctx_init(q, ctx, rq, rw);
Jens Axboe320ae512013-10-24 09:20:05 +0100934 else {
935 blk_mq_put_ctx(ctx);
936 trace_block_sleeprq(q, bio, rw);
937 rq = blk_mq_alloc_request_pinned(q, rw, __GFP_WAIT|GFP_ATOMIC,
938 false);
939 ctx = rq->mq_ctx;
940 hctx = q->mq_ops->map_queue(q, ctx->cpu);
941 }
942
943 hctx->queued++;
944
945 if (unlikely(is_flush_fua)) {
946 blk_mq_bio_to_request(rq, bio);
947 blk_mq_put_ctx(ctx);
948 blk_insert_flush(rq);
949 goto run_queue;
950 }
951
952 /*
953 * A task plug currently exists. Since this is completely lockless,
954 * utilize that to temporarily store requests until the task is
955 * either done or scheduled away.
956 */
957 if (use_plug) {
958 struct blk_plug *plug = current->plug;
959
960 if (plug) {
961 blk_mq_bio_to_request(rq, bio);
Shaohua Li92f399c2013-10-29 12:01:03 -0600962 if (list_empty(&plug->mq_list))
Jens Axboe320ae512013-10-24 09:20:05 +0100963 trace_block_plug(q);
964 else if (request_count >= BLK_MAX_REQUEST_COUNT) {
965 blk_flush_plug_list(plug, false);
966 trace_block_plug(q);
967 }
968 list_add_tail(&rq->queuelist, &plug->mq_list);
969 blk_mq_put_ctx(ctx);
970 return;
971 }
972 }
973
974 spin_lock(&ctx->lock);
975
976 if ((hctx->flags & BLK_MQ_F_SHOULD_MERGE) &&
977 blk_mq_attempt_merge(q, ctx, bio))
978 __blk_mq_free_request(hctx, ctx, rq);
979 else {
980 blk_mq_bio_to_request(rq, bio);
981 __blk_mq_insert_request(hctx, rq);
982 }
983
984 spin_unlock(&ctx->lock);
985 blk_mq_put_ctx(ctx);
986
987 /*
988 * For a SYNC request, send it to the hardware immediately. For an
989 * ASYNC request, just ensure that we run it later on. The latter
990 * allows for merging opportunities and more efficient dispatching.
991 */
992run_queue:
993 blk_mq_run_hw_queue(hctx, !is_sync || is_flush_fua);
994}
995
996/*
997 * Default mapping to a software queue, since we use one per CPU.
998 */
999struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q, const int cpu)
1000{
1001 return q->queue_hw_ctx[q->mq_map[cpu]];
1002}
1003EXPORT_SYMBOL(blk_mq_map_queue);
1004
1005struct blk_mq_hw_ctx *blk_mq_alloc_single_hw_queue(struct blk_mq_reg *reg,
1006 unsigned int hctx_index)
1007{
1008 return kmalloc_node(sizeof(struct blk_mq_hw_ctx),
1009 GFP_KERNEL | __GFP_ZERO, reg->numa_node);
1010}
1011EXPORT_SYMBOL(blk_mq_alloc_single_hw_queue);
1012
1013void blk_mq_free_single_hw_queue(struct blk_mq_hw_ctx *hctx,
1014 unsigned int hctx_index)
1015{
1016 kfree(hctx);
1017}
1018EXPORT_SYMBOL(blk_mq_free_single_hw_queue);
1019
1020static void blk_mq_hctx_notify(void *data, unsigned long action,
1021 unsigned int cpu)
1022{
1023 struct blk_mq_hw_ctx *hctx = data;
1024 struct blk_mq_ctx *ctx;
1025 LIST_HEAD(tmp);
1026
1027 if (action != CPU_DEAD && action != CPU_DEAD_FROZEN)
1028 return;
1029
1030 /*
1031 * Move ctx entries to new CPU, if this one is going away.
1032 */
1033 ctx = __blk_mq_get_ctx(hctx->queue, cpu);
1034
1035 spin_lock(&ctx->lock);
1036 if (!list_empty(&ctx->rq_list)) {
1037 list_splice_init(&ctx->rq_list, &tmp);
1038 clear_bit(ctx->index_hw, hctx->ctx_map);
1039 }
1040 spin_unlock(&ctx->lock);
1041
1042 if (list_empty(&tmp))
1043 return;
1044
1045 ctx = blk_mq_get_ctx(hctx->queue);
1046 spin_lock(&ctx->lock);
1047
1048 while (!list_empty(&tmp)) {
1049 struct request *rq;
1050
1051 rq = list_first_entry(&tmp, struct request, queuelist);
1052 rq->mq_ctx = ctx;
1053 list_move_tail(&rq->queuelist, &ctx->rq_list);
1054 }
1055
1056 blk_mq_hctx_mark_pending(hctx, ctx);
1057
1058 spin_unlock(&ctx->lock);
1059 blk_mq_put_ctx(ctx);
1060}
1061
1062static void blk_mq_init_hw_commands(struct blk_mq_hw_ctx *hctx,
1063 void (*init)(void *, struct blk_mq_hw_ctx *,
1064 struct request *, unsigned int),
1065 void *data)
1066{
1067 unsigned int i;
1068
1069 for (i = 0; i < hctx->queue_depth; i++) {
1070 struct request *rq = hctx->rqs[i];
1071
1072 init(data, hctx, rq, i);
1073 }
1074}
1075
1076void blk_mq_init_commands(struct request_queue *q,
1077 void (*init)(void *, struct blk_mq_hw_ctx *,
1078 struct request *, unsigned int),
1079 void *data)
1080{
1081 struct blk_mq_hw_ctx *hctx;
1082 unsigned int i;
1083
1084 queue_for_each_hw_ctx(q, hctx, i)
1085 blk_mq_init_hw_commands(hctx, init, data);
1086}
1087EXPORT_SYMBOL(blk_mq_init_commands);
1088
1089static void blk_mq_free_rq_map(struct blk_mq_hw_ctx *hctx)
1090{
1091 struct page *page;
1092
1093 while (!list_empty(&hctx->page_list)) {
1094 page = list_first_entry(&hctx->page_list, struct page, list);
1095 list_del_init(&page->list);
1096 __free_pages(page, page->private);
1097 }
1098
1099 kfree(hctx->rqs);
1100
1101 if (hctx->tags)
1102 blk_mq_free_tags(hctx->tags);
1103}
1104
1105static size_t order_to_size(unsigned int order)
1106{
1107 size_t ret = PAGE_SIZE;
1108
1109 while (order--)
1110 ret *= 2;
1111
1112 return ret;
1113}
1114
1115static int blk_mq_init_rq_map(struct blk_mq_hw_ctx *hctx,
1116 unsigned int reserved_tags, int node)
1117{
1118 unsigned int i, j, entries_per_page, max_order = 4;
1119 size_t rq_size, left;
1120
1121 INIT_LIST_HEAD(&hctx->page_list);
1122
1123 hctx->rqs = kmalloc_node(hctx->queue_depth * sizeof(struct request *),
1124 GFP_KERNEL, node);
1125 if (!hctx->rqs)
1126 return -ENOMEM;
1127
1128 /*
1129 * rq_size is the size of the request plus driver payload, rounded
1130 * to the cacheline size
1131 */
1132 rq_size = round_up(sizeof(struct request) + hctx->cmd_size,
1133 cache_line_size());
1134 left = rq_size * hctx->queue_depth;
1135
1136 for (i = 0; i < hctx->queue_depth;) {
1137 int this_order = max_order;
1138 struct page *page;
1139 int to_do;
1140 void *p;
1141
1142 while (left < order_to_size(this_order - 1) && this_order)
1143 this_order--;
1144
1145 do {
1146 page = alloc_pages_node(node, GFP_KERNEL, this_order);
1147 if (page)
1148 break;
1149 if (!this_order--)
1150 break;
1151 if (order_to_size(this_order) < rq_size)
1152 break;
1153 } while (1);
1154
1155 if (!page)
1156 break;
1157
1158 page->private = this_order;
1159 list_add_tail(&page->list, &hctx->page_list);
1160
1161 p = page_address(page);
1162 entries_per_page = order_to_size(this_order) / rq_size;
1163 to_do = min(entries_per_page, hctx->queue_depth - i);
1164 left -= to_do * rq_size;
1165 for (j = 0; j < to_do; j++) {
1166 hctx->rqs[i] = p;
1167 blk_mq_rq_init(hctx, hctx->rqs[i]);
1168 p += rq_size;
1169 i++;
1170 }
1171 }
1172
1173 if (i < (reserved_tags + BLK_MQ_TAG_MIN))
1174 goto err_rq_map;
1175 else if (i != hctx->queue_depth) {
1176 hctx->queue_depth = i;
1177 pr_warn("%s: queue depth set to %u because of low memory\n",
1178 __func__, i);
1179 }
1180
1181 hctx->tags = blk_mq_init_tags(hctx->queue_depth, reserved_tags, node);
1182 if (!hctx->tags) {
1183err_rq_map:
1184 blk_mq_free_rq_map(hctx);
1185 return -ENOMEM;
1186 }
1187
1188 return 0;
1189}
1190
1191static int blk_mq_init_hw_queues(struct request_queue *q,
1192 struct blk_mq_reg *reg, void *driver_data)
1193{
1194 struct blk_mq_hw_ctx *hctx;
1195 unsigned int i, j;
1196
1197 /*
1198 * Initialize hardware queues
1199 */
1200 queue_for_each_hw_ctx(q, hctx, i) {
1201 unsigned int num_maps;
1202 int node;
1203
1204 node = hctx->numa_node;
1205 if (node == NUMA_NO_NODE)
1206 node = hctx->numa_node = reg->numa_node;
1207
1208 INIT_DELAYED_WORK(&hctx->delayed_work, blk_mq_work_fn);
1209 spin_lock_init(&hctx->lock);
1210 INIT_LIST_HEAD(&hctx->dispatch);
1211 hctx->queue = q;
1212 hctx->queue_num = i;
1213 hctx->flags = reg->flags;
1214 hctx->queue_depth = reg->queue_depth;
1215 hctx->cmd_size = reg->cmd_size;
1216
1217 blk_mq_init_cpu_notifier(&hctx->cpu_notifier,
1218 blk_mq_hctx_notify, hctx);
1219 blk_mq_register_cpu_notifier(&hctx->cpu_notifier);
1220
1221 if (blk_mq_init_rq_map(hctx, reg->reserved_tags, node))
1222 break;
1223
1224 /*
1225 * Allocate space for all possible cpus to avoid allocation in
1226 * runtime
1227 */
1228 hctx->ctxs = kmalloc_node(nr_cpu_ids * sizeof(void *),
1229 GFP_KERNEL, node);
1230 if (!hctx->ctxs)
1231 break;
1232
1233 num_maps = ALIGN(nr_cpu_ids, BITS_PER_LONG) / BITS_PER_LONG;
1234 hctx->ctx_map = kzalloc_node(num_maps * sizeof(unsigned long),
1235 GFP_KERNEL, node);
1236 if (!hctx->ctx_map)
1237 break;
1238
1239 hctx->nr_ctx_map = num_maps;
1240 hctx->nr_ctx = 0;
1241
1242 if (reg->ops->init_hctx &&
1243 reg->ops->init_hctx(hctx, driver_data, i))
1244 break;
1245 }
1246
1247 if (i == q->nr_hw_queues)
1248 return 0;
1249
1250 /*
1251 * Init failed
1252 */
1253 queue_for_each_hw_ctx(q, hctx, j) {
1254 if (i == j)
1255 break;
1256
1257 if (reg->ops->exit_hctx)
1258 reg->ops->exit_hctx(hctx, j);
1259
1260 blk_mq_unregister_cpu_notifier(&hctx->cpu_notifier);
1261 blk_mq_free_rq_map(hctx);
1262 kfree(hctx->ctxs);
1263 }
1264
1265 return 1;
1266}
1267
1268static void blk_mq_init_cpu_queues(struct request_queue *q,
1269 unsigned int nr_hw_queues)
1270{
1271 unsigned int i;
1272
1273 for_each_possible_cpu(i) {
1274 struct blk_mq_ctx *__ctx = per_cpu_ptr(q->queue_ctx, i);
1275 struct blk_mq_hw_ctx *hctx;
1276
1277 memset(__ctx, 0, sizeof(*__ctx));
1278 __ctx->cpu = i;
1279 spin_lock_init(&__ctx->lock);
1280 INIT_LIST_HEAD(&__ctx->rq_list);
1281 __ctx->queue = q;
1282
1283 /* If the cpu isn't online, the cpu is mapped to first hctx */
1284 hctx = q->mq_ops->map_queue(q, i);
1285 hctx->nr_ctx++;
1286
1287 if (!cpu_online(i))
1288 continue;
1289
1290 /*
1291 * Set local node, IFF we have more than one hw queue. If
1292 * not, we remain on the home node of the device
1293 */
1294 if (nr_hw_queues > 1 && hctx->numa_node == NUMA_NO_NODE)
1295 hctx->numa_node = cpu_to_node(i);
1296 }
1297}
1298
1299static void blk_mq_map_swqueue(struct request_queue *q)
1300{
1301 unsigned int i;
1302 struct blk_mq_hw_ctx *hctx;
1303 struct blk_mq_ctx *ctx;
1304
1305 queue_for_each_hw_ctx(q, hctx, i) {
1306 hctx->nr_ctx = 0;
1307 }
1308
1309 /*
1310 * Map software to hardware queues
1311 */
1312 queue_for_each_ctx(q, ctx, i) {
1313 /* If the cpu isn't online, the cpu is mapped to first hctx */
1314 hctx = q->mq_ops->map_queue(q, i);
1315 ctx->index_hw = hctx->nr_ctx;
1316 hctx->ctxs[hctx->nr_ctx++] = ctx;
1317 }
1318}
1319
1320struct request_queue *blk_mq_init_queue(struct blk_mq_reg *reg,
1321 void *driver_data)
1322{
1323 struct blk_mq_hw_ctx **hctxs;
1324 struct blk_mq_ctx *ctx;
1325 struct request_queue *q;
1326 int i;
1327
1328 if (!reg->nr_hw_queues ||
1329 !reg->ops->queue_rq || !reg->ops->map_queue ||
1330 !reg->ops->alloc_hctx || !reg->ops->free_hctx)
1331 return ERR_PTR(-EINVAL);
1332
1333 if (!reg->queue_depth)
1334 reg->queue_depth = BLK_MQ_MAX_DEPTH;
1335 else if (reg->queue_depth > BLK_MQ_MAX_DEPTH) {
1336 pr_err("blk-mq: queuedepth too large (%u)\n", reg->queue_depth);
1337 reg->queue_depth = BLK_MQ_MAX_DEPTH;
1338 }
1339
Christoph Hellwig3228f482013-10-28 13:33:58 -06001340 /*
1341 * Set aside a tag for flush requests. It will only be used while
1342 * another flush request is in progress but outside the driver.
1343 *
1344 * TODO: only allocate if flushes are supported
1345 */
1346 reg->queue_depth++;
1347 reg->reserved_tags++;
1348
Jens Axboe320ae512013-10-24 09:20:05 +01001349 if (reg->queue_depth < (reg->reserved_tags + BLK_MQ_TAG_MIN))
1350 return ERR_PTR(-EINVAL);
1351
1352 ctx = alloc_percpu(struct blk_mq_ctx);
1353 if (!ctx)
1354 return ERR_PTR(-ENOMEM);
1355
1356 hctxs = kmalloc_node(reg->nr_hw_queues * sizeof(*hctxs), GFP_KERNEL,
1357 reg->numa_node);
1358
1359 if (!hctxs)
1360 goto err_percpu;
1361
1362 for (i = 0; i < reg->nr_hw_queues; i++) {
1363 hctxs[i] = reg->ops->alloc_hctx(reg, i);
1364 if (!hctxs[i])
1365 goto err_hctxs;
1366
1367 hctxs[i]->numa_node = NUMA_NO_NODE;
1368 hctxs[i]->queue_num = i;
1369 }
1370
1371 q = blk_alloc_queue_node(GFP_KERNEL, reg->numa_node);
1372 if (!q)
1373 goto err_hctxs;
1374
1375 q->mq_map = blk_mq_make_queue_map(reg);
1376 if (!q->mq_map)
1377 goto err_map;
1378
1379 setup_timer(&q->timeout, blk_mq_rq_timer, (unsigned long) q);
1380 blk_queue_rq_timeout(q, 30000);
1381
1382 q->nr_queues = nr_cpu_ids;
1383 q->nr_hw_queues = reg->nr_hw_queues;
1384
1385 q->queue_ctx = ctx;
1386 q->queue_hw_ctx = hctxs;
1387
1388 q->mq_ops = reg->ops;
Jens Axboe94eddfb2013-11-19 09:25:07 -07001389 q->queue_flags |= QUEUE_FLAG_MQ_DEFAULT;
Jens Axboe320ae512013-10-24 09:20:05 +01001390
1391 blk_queue_make_request(q, blk_mq_make_request);
1392 blk_queue_rq_timed_out(q, reg->ops->timeout);
1393 if (reg->timeout)
1394 blk_queue_rq_timeout(q, reg->timeout);
1395
1396 blk_mq_init_flush(q);
1397 blk_mq_init_cpu_queues(q, reg->nr_hw_queues);
1398
1399 if (blk_mq_init_hw_queues(q, reg, driver_data))
1400 goto err_hw;
1401
1402 blk_mq_map_swqueue(q);
1403
1404 mutex_lock(&all_q_mutex);
1405 list_add_tail(&q->all_q_node, &all_q_list);
1406 mutex_unlock(&all_q_mutex);
1407
1408 return q;
1409err_hw:
1410 kfree(q->mq_map);
1411err_map:
1412 blk_cleanup_queue(q);
1413err_hctxs:
1414 for (i = 0; i < reg->nr_hw_queues; i++) {
1415 if (!hctxs[i])
1416 break;
1417 reg->ops->free_hctx(hctxs[i], i);
1418 }
1419 kfree(hctxs);
1420err_percpu:
1421 free_percpu(ctx);
1422 return ERR_PTR(-ENOMEM);
1423}
1424EXPORT_SYMBOL(blk_mq_init_queue);
1425
1426void blk_mq_free_queue(struct request_queue *q)
1427{
1428 struct blk_mq_hw_ctx *hctx;
1429 int i;
1430
1431 queue_for_each_hw_ctx(q, hctx, i) {
1432 cancel_delayed_work_sync(&hctx->delayed_work);
1433 kfree(hctx->ctx_map);
1434 kfree(hctx->ctxs);
1435 blk_mq_free_rq_map(hctx);
1436 blk_mq_unregister_cpu_notifier(&hctx->cpu_notifier);
1437 if (q->mq_ops->exit_hctx)
1438 q->mq_ops->exit_hctx(hctx, i);
1439 q->mq_ops->free_hctx(hctx, i);
1440 }
1441
1442 free_percpu(q->queue_ctx);
1443 kfree(q->queue_hw_ctx);
1444 kfree(q->mq_map);
1445
1446 q->queue_ctx = NULL;
1447 q->queue_hw_ctx = NULL;
1448 q->mq_map = NULL;
1449
1450 mutex_lock(&all_q_mutex);
1451 list_del_init(&q->all_q_node);
1452 mutex_unlock(&all_q_mutex);
1453}
1454EXPORT_SYMBOL(blk_mq_free_queue);
1455
1456/* Basically redo blk_mq_init_queue with queue frozen */
Paul Gortmakerf618ef72013-11-14 08:26:02 -07001457static void blk_mq_queue_reinit(struct request_queue *q)
Jens Axboe320ae512013-10-24 09:20:05 +01001458{
1459 blk_mq_freeze_queue(q);
1460
1461 blk_mq_update_queue_map(q->mq_map, q->nr_hw_queues);
1462
1463 /*
1464 * redo blk_mq_init_cpu_queues and blk_mq_init_hw_queues. FIXME: maybe
1465 * we should change hctx numa_node according to new topology (this
1466 * involves free and re-allocate memory, worthy doing?)
1467 */
1468
1469 blk_mq_map_swqueue(q);
1470
1471 blk_mq_unfreeze_queue(q);
1472}
1473
Paul Gortmakerf618ef72013-11-14 08:26:02 -07001474static int blk_mq_queue_reinit_notify(struct notifier_block *nb,
1475 unsigned long action, void *hcpu)
Jens Axboe320ae512013-10-24 09:20:05 +01001476{
1477 struct request_queue *q;
1478
1479 /*
1480 * Before new mapping is established, hotadded cpu might already start
1481 * handling requests. This doesn't break anything as we map offline
1482 * CPUs to first hardware queue. We will re-init queue below to get
1483 * optimal settings.
1484 */
1485 if (action != CPU_DEAD && action != CPU_DEAD_FROZEN &&
1486 action != CPU_ONLINE && action != CPU_ONLINE_FROZEN)
1487 return NOTIFY_OK;
1488
1489 mutex_lock(&all_q_mutex);
1490 list_for_each_entry(q, &all_q_list, all_q_node)
1491 blk_mq_queue_reinit(q);
1492 mutex_unlock(&all_q_mutex);
1493 return NOTIFY_OK;
1494}
1495
1496static int __init blk_mq_init(void)
1497{
1498 unsigned int i;
1499
1500 for_each_possible_cpu(i)
1501 init_llist_head(&per_cpu(ipi_lists, i));
1502
1503 blk_mq_cpu_init();
1504
1505 /* Must be called after percpu_counter_hotcpu_callback() */
1506 hotcpu_notifier(blk_mq_queue_reinit_notify, -10);
1507
1508 return 0;
1509}
1510subsys_initcall(blk_mq_init);