blob: 57039fcd9c93e7c3e014842fbbcaf2fc6550edd1 [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
Jens Axboe320ae512013-10-24 09:20:05 +010030static struct blk_mq_ctx *__blk_mq_get_ctx(struct request_queue *q,
31 unsigned int cpu)
32{
33 return per_cpu_ptr(q->queue_ctx, cpu);
34}
35
36/*
37 * This assumes per-cpu software queueing queues. They could be per-node
38 * as well, for instance. For now this is hardcoded as-is. Note that we don't
39 * care about preemption, since we know the ctx's are persistent. This does
40 * mean that we can't rely on ctx always matching the currently running CPU.
41 */
42static struct blk_mq_ctx *blk_mq_get_ctx(struct request_queue *q)
43{
44 return __blk_mq_get_ctx(q, get_cpu());
45}
46
47static void blk_mq_put_ctx(struct blk_mq_ctx *ctx)
48{
49 put_cpu();
50}
51
52/*
53 * Check if any of the ctx's have pending work in this hardware queue
54 */
55static bool blk_mq_hctx_has_pending(struct blk_mq_hw_ctx *hctx)
56{
57 unsigned int i;
58
59 for (i = 0; i < hctx->nr_ctx_map; i++)
60 if (hctx->ctx_map[i])
61 return true;
62
63 return false;
64}
65
66/*
67 * Mark this ctx as having pending work in this hardware queue
68 */
69static void blk_mq_hctx_mark_pending(struct blk_mq_hw_ctx *hctx,
70 struct blk_mq_ctx *ctx)
71{
72 if (!test_bit(ctx->index_hw, hctx->ctx_map))
73 set_bit(ctx->index_hw, hctx->ctx_map);
74}
75
76static struct request *blk_mq_alloc_rq(struct blk_mq_hw_ctx *hctx, gfp_t gfp,
77 bool reserved)
78{
79 struct request *rq;
80 unsigned int tag;
81
82 tag = blk_mq_get_tag(hctx->tags, gfp, reserved);
83 if (tag != BLK_MQ_TAG_FAIL) {
84 rq = hctx->rqs[tag];
85 rq->tag = tag;
86
87 return rq;
88 }
89
90 return NULL;
91}
92
93static int blk_mq_queue_enter(struct request_queue *q)
94{
95 int ret;
96
97 __percpu_counter_add(&q->mq_usage_counter, 1, 1000000);
98 smp_wmb();
99 /* we have problems to freeze the queue if it's initializing */
100 if (!blk_queue_bypass(q) || !blk_queue_init_done(q))
101 return 0;
102
103 __percpu_counter_add(&q->mq_usage_counter, -1, 1000000);
104
105 spin_lock_irq(q->queue_lock);
106 ret = wait_event_interruptible_lock_irq(q->mq_freeze_wq,
Ming Lei43a5e4e2013-12-26 21:31:35 +0800107 !blk_queue_bypass(q) || blk_queue_dying(q),
108 *q->queue_lock);
Jens Axboe320ae512013-10-24 09:20:05 +0100109 /* inc usage with lock hold to avoid freeze_queue runs here */
Ming Lei43a5e4e2013-12-26 21:31:35 +0800110 if (!ret && !blk_queue_dying(q))
Jens Axboe320ae512013-10-24 09:20:05 +0100111 __percpu_counter_add(&q->mq_usage_counter, 1, 1000000);
Ming Lei43a5e4e2013-12-26 21:31:35 +0800112 else if (blk_queue_dying(q))
113 ret = -ENODEV;
Jens Axboe320ae512013-10-24 09:20:05 +0100114 spin_unlock_irq(q->queue_lock);
115
116 return ret;
117}
118
119static void blk_mq_queue_exit(struct request_queue *q)
120{
121 __percpu_counter_add(&q->mq_usage_counter, -1, 1000000);
122}
123
Ming Lei43a5e4e2013-12-26 21:31:35 +0800124static void __blk_mq_drain_queue(struct request_queue *q)
125{
126 while (true) {
127 s64 count;
128
129 spin_lock_irq(q->queue_lock);
130 count = percpu_counter_sum(&q->mq_usage_counter);
131 spin_unlock_irq(q->queue_lock);
132
133 if (count == 0)
134 break;
135 blk_mq_run_queues(q, false);
136 msleep(10);
137 }
138}
139
Jens Axboe320ae512013-10-24 09:20:05 +0100140/*
141 * Guarantee no request is in use, so we can change any data structure of
142 * the queue afterward.
143 */
144static void blk_mq_freeze_queue(struct request_queue *q)
145{
146 bool drain;
147
148 spin_lock_irq(q->queue_lock);
149 drain = !q->bypass_depth++;
150 queue_flag_set(QUEUE_FLAG_BYPASS, q);
151 spin_unlock_irq(q->queue_lock);
152
Ming Lei43a5e4e2013-12-26 21:31:35 +0800153 if (drain)
154 __blk_mq_drain_queue(q);
155}
Jens Axboe320ae512013-10-24 09:20:05 +0100156
Ming Lei43a5e4e2013-12-26 21:31:35 +0800157void blk_mq_drain_queue(struct request_queue *q)
158{
159 __blk_mq_drain_queue(q);
Jens Axboe320ae512013-10-24 09:20:05 +0100160}
161
162static void blk_mq_unfreeze_queue(struct request_queue *q)
163{
164 bool wake = false;
165
166 spin_lock_irq(q->queue_lock);
167 if (!--q->bypass_depth) {
168 queue_flag_clear(QUEUE_FLAG_BYPASS, q);
169 wake = true;
170 }
171 WARN_ON_ONCE(q->bypass_depth < 0);
172 spin_unlock_irq(q->queue_lock);
173 if (wake)
174 wake_up_all(&q->mq_freeze_wq);
175}
176
177bool blk_mq_can_queue(struct blk_mq_hw_ctx *hctx)
178{
179 return blk_mq_has_free_tags(hctx->tags);
180}
181EXPORT_SYMBOL(blk_mq_can_queue);
182
Jens Axboe94eddfb2013-11-19 09:25:07 -0700183static void blk_mq_rq_ctx_init(struct request_queue *q, struct blk_mq_ctx *ctx,
184 struct request *rq, unsigned int rw_flags)
Jens Axboe320ae512013-10-24 09:20:05 +0100185{
Jens Axboe94eddfb2013-11-19 09:25:07 -0700186 if (blk_queue_io_stat(q))
187 rw_flags |= REQ_IO_STAT;
188
Jens Axboe320ae512013-10-24 09:20:05 +0100189 rq->mq_ctx = ctx;
190 rq->cmd_flags = rw_flags;
Ming Lei0fec08b2014-01-03 10:00:08 -0700191 rq->start_time = jiffies;
192 set_start_time_ns(rq);
Jens Axboe320ae512013-10-24 09:20:05 +0100193 ctx->rq_dispatched[rw_is_sync(rw_flags)]++;
194}
195
196static struct request *__blk_mq_alloc_request(struct blk_mq_hw_ctx *hctx,
197 gfp_t gfp, bool reserved)
198{
199 return blk_mq_alloc_rq(hctx, gfp, reserved);
200}
201
202static struct request *blk_mq_alloc_request_pinned(struct request_queue *q,
203 int rw, gfp_t gfp,
204 bool reserved)
205{
206 struct request *rq;
207
208 do {
209 struct blk_mq_ctx *ctx = blk_mq_get_ctx(q);
210 struct blk_mq_hw_ctx *hctx = q->mq_ops->map_queue(q, ctx->cpu);
211
212 rq = __blk_mq_alloc_request(hctx, gfp & ~__GFP_WAIT, reserved);
213 if (rq) {
Jens Axboe94eddfb2013-11-19 09:25:07 -0700214 blk_mq_rq_ctx_init(q, ctx, rq, rw);
Jens Axboe320ae512013-10-24 09:20:05 +0100215 break;
Jeff Moyer959a35f2013-12-03 14:23:00 -0700216 }
Jens Axboe320ae512013-10-24 09:20:05 +0100217
218 blk_mq_put_ctx(ctx);
Jeff Moyer959a35f2013-12-03 14:23:00 -0700219 if (!(gfp & __GFP_WAIT))
220 break;
221
Jens Axboe320ae512013-10-24 09:20:05 +0100222 __blk_mq_run_hw_queue(hctx);
223 blk_mq_wait_for_tags(hctx->tags);
224 } while (1);
225
226 return rq;
227}
228
Christoph Hellwig3228f482013-10-28 13:33:58 -0600229struct request *blk_mq_alloc_request(struct request_queue *q, int rw,
230 gfp_t gfp, bool reserved)
Jens Axboe320ae512013-10-24 09:20:05 +0100231{
232 struct request *rq;
233
234 if (blk_mq_queue_enter(q))
235 return NULL;
236
Christoph Hellwig3228f482013-10-28 13:33:58 -0600237 rq = blk_mq_alloc_request_pinned(q, rw, gfp, reserved);
Jeff Moyer959a35f2013-12-03 14:23:00 -0700238 if (rq)
239 blk_mq_put_ctx(rq->mq_ctx);
Jens Axboe320ae512013-10-24 09:20:05 +0100240 return rq;
241}
242
243struct request *blk_mq_alloc_reserved_request(struct request_queue *q, int rw,
244 gfp_t gfp)
245{
246 struct request *rq;
247
248 if (blk_mq_queue_enter(q))
249 return NULL;
250
251 rq = blk_mq_alloc_request_pinned(q, rw, gfp, true);
Jeff Moyer959a35f2013-12-03 14:23:00 -0700252 if (rq)
253 blk_mq_put_ctx(rq->mq_ctx);
Jens Axboe320ae512013-10-24 09:20:05 +0100254 return rq;
255}
256EXPORT_SYMBOL(blk_mq_alloc_reserved_request);
257
258/*
259 * Re-init and set pdu, if we have it
260 */
261static void blk_mq_rq_init(struct blk_mq_hw_ctx *hctx, struct request *rq)
262{
263 blk_rq_init(hctx->queue, rq);
264
265 if (hctx->cmd_size)
266 rq->special = blk_mq_rq_to_pdu(rq);
267}
268
269static void __blk_mq_free_request(struct blk_mq_hw_ctx *hctx,
270 struct blk_mq_ctx *ctx, struct request *rq)
271{
272 const int tag = rq->tag;
273 struct request_queue *q = rq->q;
274
275 blk_mq_rq_init(hctx, rq);
276 blk_mq_put_tag(hctx->tags, tag);
277
278 blk_mq_queue_exit(q);
279}
280
281void blk_mq_free_request(struct request *rq)
282{
283 struct blk_mq_ctx *ctx = rq->mq_ctx;
284 struct blk_mq_hw_ctx *hctx;
285 struct request_queue *q = rq->q;
286
287 ctx->rq_completed[rq_is_sync(rq)]++;
288
289 hctx = q->mq_ops->map_queue(q, ctx->cpu);
290 __blk_mq_free_request(hctx, ctx, rq);
291}
292
293static void blk_mq_bio_endio(struct request *rq, struct bio *bio, int error)
294{
295 if (error)
296 clear_bit(BIO_UPTODATE, &bio->bi_flags);
297 else if (!test_bit(BIO_UPTODATE, &bio->bi_flags))
298 error = -EIO;
299
300 if (unlikely(rq->cmd_flags & REQ_QUIET))
301 set_bit(BIO_QUIET, &bio->bi_flags);
302
303 /* don't actually finish bio if it's part of flush sequence */
304 if (!(rq->cmd_flags & REQ_FLUSH_SEQ))
305 bio_endio(bio, error);
306}
307
308void blk_mq_complete_request(struct request *rq, int error)
309{
310 struct bio *bio = rq->bio;
311 unsigned int bytes = 0;
312
313 trace_block_rq_complete(rq->q, rq);
314
315 while (bio) {
316 struct bio *next = bio->bi_next;
317
318 bio->bi_next = NULL;
Kent Overstreet4f024f32013-10-11 15:44:27 -0700319 bytes += bio->bi_iter.bi_size;
Jens Axboe320ae512013-10-24 09:20:05 +0100320 blk_mq_bio_endio(rq, bio, error);
321 bio = next;
322 }
323
324 blk_account_io_completion(rq, bytes);
325
Ming Lei0d11e6a2013-12-05 10:50:39 -0700326 blk_account_io_done(rq);
327
Jens Axboe320ae512013-10-24 09:20:05 +0100328 if (rq->end_io)
329 rq->end_io(rq, error);
330 else
331 blk_mq_free_request(rq);
Jens Axboe320ae512013-10-24 09:20:05 +0100332}
333
334void __blk_mq_end_io(struct request *rq, int error)
335{
336 if (!blk_mark_rq_complete(rq))
337 blk_mq_complete_request(rq, error);
338}
339
Christoph Hellwig3d6efbf2014-01-08 09:33:37 -0800340static void blk_mq_end_io_remote(void *data)
Jens Axboe320ae512013-10-24 09:20:05 +0100341{
Christoph Hellwig3d6efbf2014-01-08 09:33:37 -0800342 struct request *rq = data;
Jens Axboe320ae512013-10-24 09:20:05 +0100343
Christoph Hellwig3d6efbf2014-01-08 09:33:37 -0800344 __blk_mq_end_io(rq, rq->errors);
Jens Axboe320ae512013-10-24 09:20:05 +0100345}
346
Jens Axboe320ae512013-10-24 09:20:05 +0100347/*
348 * End IO on this request on a multiqueue enabled driver. We'll either do
349 * it directly inline, or punt to a local IPI handler on the matching
350 * remote CPU.
351 */
352void blk_mq_end_io(struct request *rq, int error)
353{
354 struct blk_mq_ctx *ctx = rq->mq_ctx;
355 int cpu;
356
357 if (!ctx->ipi_redirect)
358 return __blk_mq_end_io(rq, error);
359
360 cpu = get_cpu();
Christoph Hellwig3d6efbf2014-01-08 09:33:37 -0800361 if (cpu != ctx->cpu && cpu_online(ctx->cpu)) {
362 rq->errors = error;
363 rq->csd.func = blk_mq_end_io_remote;
364 rq->csd.info = rq;
365 rq->csd.flags = 0;
366 __smp_call_function_single(ctx->cpu, &rq->csd, 0);
367 } else {
Jens Axboe320ae512013-10-24 09:20:05 +0100368 __blk_mq_end_io(rq, error);
Christoph Hellwig3d6efbf2014-01-08 09:33:37 -0800369 }
Jens Axboe320ae512013-10-24 09:20:05 +0100370 put_cpu();
371}
372EXPORT_SYMBOL(blk_mq_end_io);
373
374static void blk_mq_start_request(struct request *rq)
375{
376 struct request_queue *q = rq->q;
377
378 trace_block_rq_issue(q, rq);
379
380 /*
381 * Just mark start time and set the started bit. Due to memory
382 * ordering, we know we'll see the correct deadline as long as
383 * REQ_ATOMIC_STARTED is seen.
384 */
385 rq->deadline = jiffies + q->rq_timeout;
386 set_bit(REQ_ATOM_STARTED, &rq->atomic_flags);
387}
388
389static void blk_mq_requeue_request(struct request *rq)
390{
391 struct request_queue *q = rq->q;
392
393 trace_block_rq_requeue(q, rq);
394 clear_bit(REQ_ATOM_STARTED, &rq->atomic_flags);
395}
396
397struct blk_mq_timeout_data {
398 struct blk_mq_hw_ctx *hctx;
399 unsigned long *next;
400 unsigned int *next_set;
401};
402
403static void blk_mq_timeout_check(void *__data, unsigned long *free_tags)
404{
405 struct blk_mq_timeout_data *data = __data;
406 struct blk_mq_hw_ctx *hctx = data->hctx;
407 unsigned int tag;
408
409 /* It may not be in flight yet (this is where
410 * the REQ_ATOMIC_STARTED flag comes in). The requests are
411 * statically allocated, so we know it's always safe to access the
412 * memory associated with a bit offset into ->rqs[].
413 */
414 tag = 0;
415 do {
416 struct request *rq;
417
418 tag = find_next_zero_bit(free_tags, hctx->queue_depth, tag);
419 if (tag >= hctx->queue_depth)
420 break;
421
422 rq = hctx->rqs[tag++];
423
424 if (!test_bit(REQ_ATOM_STARTED, &rq->atomic_flags))
425 continue;
426
427 blk_rq_check_expired(rq, data->next, data->next_set);
428 } while (1);
429}
430
431static void blk_mq_hw_ctx_check_timeout(struct blk_mq_hw_ctx *hctx,
432 unsigned long *next,
433 unsigned int *next_set)
434{
435 struct blk_mq_timeout_data data = {
436 .hctx = hctx,
437 .next = next,
438 .next_set = next_set,
439 };
440
441 /*
442 * Ask the tagging code to iterate busy requests, so we can
443 * check them for timeout.
444 */
445 blk_mq_tag_busy_iter(hctx->tags, blk_mq_timeout_check, &data);
446}
447
448static void blk_mq_rq_timer(unsigned long data)
449{
450 struct request_queue *q = (struct request_queue *) data;
451 struct blk_mq_hw_ctx *hctx;
452 unsigned long next = 0;
453 int i, next_set = 0;
454
455 queue_for_each_hw_ctx(q, hctx, i)
456 blk_mq_hw_ctx_check_timeout(hctx, &next, &next_set);
457
458 if (next_set)
459 mod_timer(&q->timeout, round_jiffies_up(next));
460}
461
462/*
463 * Reverse check our software queue for entries that we could potentially
464 * merge with. Currently includes a hand-wavy stop count of 8, to not spend
465 * too much time checking for merges.
466 */
467static bool blk_mq_attempt_merge(struct request_queue *q,
468 struct blk_mq_ctx *ctx, struct bio *bio)
469{
470 struct request *rq;
471 int checked = 8;
472
473 list_for_each_entry_reverse(rq, &ctx->rq_list, queuelist) {
474 int el_ret;
475
476 if (!checked--)
477 break;
478
479 if (!blk_rq_merge_ok(rq, bio))
480 continue;
481
482 el_ret = blk_try_merge(rq, bio);
483 if (el_ret == ELEVATOR_BACK_MERGE) {
484 if (bio_attempt_back_merge(q, rq, bio)) {
485 ctx->rq_merged++;
486 return true;
487 }
488 break;
489 } else if (el_ret == ELEVATOR_FRONT_MERGE) {
490 if (bio_attempt_front_merge(q, rq, bio)) {
491 ctx->rq_merged++;
492 return true;
493 }
494 break;
495 }
496 }
497
498 return false;
499}
500
501void blk_mq_add_timer(struct request *rq)
502{
503 __blk_add_timer(rq, NULL);
504}
505
506/*
507 * Run this hardware queue, pulling any software queues mapped to it in.
508 * Note that this function currently has various problems around ordering
509 * of IO. In particular, we'd like FIFO behaviour on handling existing
510 * items on the hctx->dispatch list. Ignore that for now.
511 */
512static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx)
513{
514 struct request_queue *q = hctx->queue;
515 struct blk_mq_ctx *ctx;
516 struct request *rq;
517 LIST_HEAD(rq_list);
518 int bit, queued;
519
520 if (unlikely(test_bit(BLK_MQ_S_STOPPED, &hctx->flags)))
521 return;
522
523 hctx->run++;
524
525 /*
526 * Touch any software queue that has pending entries.
527 */
528 for_each_set_bit(bit, hctx->ctx_map, hctx->nr_ctx) {
529 clear_bit(bit, hctx->ctx_map);
530 ctx = hctx->ctxs[bit];
531 BUG_ON(bit != ctx->index_hw);
532
533 spin_lock(&ctx->lock);
534 list_splice_tail_init(&ctx->rq_list, &rq_list);
535 spin_unlock(&ctx->lock);
536 }
537
538 /*
539 * If we have previous entries on our dispatch list, grab them
540 * and stuff them at the front for more fair dispatch.
541 */
542 if (!list_empty_careful(&hctx->dispatch)) {
543 spin_lock(&hctx->lock);
544 if (!list_empty(&hctx->dispatch))
545 list_splice_init(&hctx->dispatch, &rq_list);
546 spin_unlock(&hctx->lock);
547 }
548
549 /*
550 * Delete and return all entries from our dispatch list
551 */
552 queued = 0;
553
554 /*
555 * Now process all the entries, sending them to the driver.
556 */
557 while (!list_empty(&rq_list)) {
558 int ret;
559
560 rq = list_first_entry(&rq_list, struct request, queuelist);
561 list_del_init(&rq->queuelist);
562 blk_mq_start_request(rq);
563
564 /*
565 * Last request in the series. Flag it as such, this
566 * enables drivers to know when IO should be kicked off,
567 * if they don't do it on a per-request basis.
568 *
569 * Note: the flag isn't the only condition drivers
570 * should do kick off. If drive is busy, the last
571 * request might not have the bit set.
572 */
573 if (list_empty(&rq_list))
574 rq->cmd_flags |= REQ_END;
575
576 ret = q->mq_ops->queue_rq(hctx, rq);
577 switch (ret) {
578 case BLK_MQ_RQ_QUEUE_OK:
579 queued++;
580 continue;
581 case BLK_MQ_RQ_QUEUE_BUSY:
582 /*
583 * FIXME: we should have a mechanism to stop the queue
584 * like blk_stop_queue, otherwise we will waste cpu
585 * time
586 */
587 list_add(&rq->queuelist, &rq_list);
588 blk_mq_requeue_request(rq);
589 break;
590 default:
591 pr_err("blk-mq: bad return on queue: %d\n", ret);
592 rq->errors = -EIO;
593 case BLK_MQ_RQ_QUEUE_ERROR:
594 blk_mq_end_io(rq, rq->errors);
595 break;
596 }
597
598 if (ret == BLK_MQ_RQ_QUEUE_BUSY)
599 break;
600 }
601
602 if (!queued)
603 hctx->dispatched[0]++;
604 else if (queued < (1 << (BLK_MQ_MAX_DISPATCH_ORDER - 1)))
605 hctx->dispatched[ilog2(queued) + 1]++;
606
607 /*
608 * Any items that need requeuing? Stuff them into hctx->dispatch,
609 * that is where we will continue on next queue run.
610 */
611 if (!list_empty(&rq_list)) {
612 spin_lock(&hctx->lock);
613 list_splice(&rq_list, &hctx->dispatch);
614 spin_unlock(&hctx->lock);
615 }
616}
617
618void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async)
619{
620 if (unlikely(test_bit(BLK_MQ_S_STOPPED, &hctx->flags)))
621 return;
622
623 if (!async)
624 __blk_mq_run_hw_queue(hctx);
625 else {
626 struct request_queue *q = hctx->queue;
627
628 kblockd_schedule_delayed_work(q, &hctx->delayed_work, 0);
629 }
630}
631
632void blk_mq_run_queues(struct request_queue *q, bool async)
633{
634 struct blk_mq_hw_ctx *hctx;
635 int i;
636
637 queue_for_each_hw_ctx(q, hctx, i) {
638 if ((!blk_mq_hctx_has_pending(hctx) &&
639 list_empty_careful(&hctx->dispatch)) ||
640 test_bit(BLK_MQ_S_STOPPED, &hctx->flags))
641 continue;
642
643 blk_mq_run_hw_queue(hctx, async);
644 }
645}
646EXPORT_SYMBOL(blk_mq_run_queues);
647
648void blk_mq_stop_hw_queue(struct blk_mq_hw_ctx *hctx)
649{
650 cancel_delayed_work(&hctx->delayed_work);
651 set_bit(BLK_MQ_S_STOPPED, &hctx->state);
652}
653EXPORT_SYMBOL(blk_mq_stop_hw_queue);
654
Christoph Hellwig280d45f2013-10-25 14:45:58 +0100655void blk_mq_stop_hw_queues(struct request_queue *q)
656{
657 struct blk_mq_hw_ctx *hctx;
658 int i;
659
660 queue_for_each_hw_ctx(q, hctx, i)
661 blk_mq_stop_hw_queue(hctx);
662}
663EXPORT_SYMBOL(blk_mq_stop_hw_queues);
664
Jens Axboe320ae512013-10-24 09:20:05 +0100665void blk_mq_start_hw_queue(struct blk_mq_hw_ctx *hctx)
666{
667 clear_bit(BLK_MQ_S_STOPPED, &hctx->state);
668 __blk_mq_run_hw_queue(hctx);
669}
670EXPORT_SYMBOL(blk_mq_start_hw_queue);
671
672void blk_mq_start_stopped_hw_queues(struct request_queue *q)
673{
674 struct blk_mq_hw_ctx *hctx;
675 int i;
676
677 queue_for_each_hw_ctx(q, hctx, i) {
678 if (!test_bit(BLK_MQ_S_STOPPED, &hctx->state))
679 continue;
680
681 clear_bit(BLK_MQ_S_STOPPED, &hctx->state);
682 blk_mq_run_hw_queue(hctx, true);
683 }
684}
685EXPORT_SYMBOL(blk_mq_start_stopped_hw_queues);
686
687static void blk_mq_work_fn(struct work_struct *work)
688{
689 struct blk_mq_hw_ctx *hctx;
690
691 hctx = container_of(work, struct blk_mq_hw_ctx, delayed_work.work);
692 __blk_mq_run_hw_queue(hctx);
693}
694
695static void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx,
696 struct request *rq)
697{
698 struct blk_mq_ctx *ctx = rq->mq_ctx;
699
Jens Axboe01b983c2013-11-19 18:59:10 -0700700 trace_block_rq_insert(hctx->queue, rq);
701
Jens Axboe320ae512013-10-24 09:20:05 +0100702 list_add_tail(&rq->queuelist, &ctx->rq_list);
703 blk_mq_hctx_mark_pending(hctx, ctx);
704
705 /*
706 * We do this early, to ensure we are on the right CPU.
707 */
708 blk_mq_add_timer(rq);
709}
710
711void blk_mq_insert_request(struct request_queue *q, struct request *rq,
712 bool run_queue)
713{
714 struct blk_mq_hw_ctx *hctx;
715 struct blk_mq_ctx *ctx, *current_ctx;
716
717 ctx = rq->mq_ctx;
718 hctx = q->mq_ops->map_queue(q, ctx->cpu);
719
720 if (rq->cmd_flags & (REQ_FLUSH | REQ_FUA)) {
721 blk_insert_flush(rq);
722 } else {
723 current_ctx = blk_mq_get_ctx(q);
724
725 if (!cpu_online(ctx->cpu)) {
726 ctx = current_ctx;
727 hctx = q->mq_ops->map_queue(q, ctx->cpu);
728 rq->mq_ctx = ctx;
729 }
730 spin_lock(&ctx->lock);
731 __blk_mq_insert_request(hctx, rq);
732 spin_unlock(&ctx->lock);
733
734 blk_mq_put_ctx(current_ctx);
735 }
736
737 if (run_queue)
738 __blk_mq_run_hw_queue(hctx);
739}
740EXPORT_SYMBOL(blk_mq_insert_request);
741
742/*
743 * This is a special version of blk_mq_insert_request to bypass FLUSH request
744 * check. Should only be used internally.
745 */
746void blk_mq_run_request(struct request *rq, bool run_queue, bool async)
747{
748 struct request_queue *q = rq->q;
749 struct blk_mq_hw_ctx *hctx;
750 struct blk_mq_ctx *ctx, *current_ctx;
751
752 current_ctx = blk_mq_get_ctx(q);
753
754 ctx = rq->mq_ctx;
755 if (!cpu_online(ctx->cpu)) {
756 ctx = current_ctx;
757 rq->mq_ctx = ctx;
758 }
759 hctx = q->mq_ops->map_queue(q, ctx->cpu);
760
761 /* ctx->cpu might be offline */
762 spin_lock(&ctx->lock);
763 __blk_mq_insert_request(hctx, rq);
764 spin_unlock(&ctx->lock);
765
766 blk_mq_put_ctx(current_ctx);
767
768 if (run_queue)
769 blk_mq_run_hw_queue(hctx, async);
770}
771
772static void blk_mq_insert_requests(struct request_queue *q,
773 struct blk_mq_ctx *ctx,
774 struct list_head *list,
775 int depth,
776 bool from_schedule)
777
778{
779 struct blk_mq_hw_ctx *hctx;
780 struct blk_mq_ctx *current_ctx;
781
782 trace_block_unplug(q, depth, !from_schedule);
783
784 current_ctx = blk_mq_get_ctx(q);
785
786 if (!cpu_online(ctx->cpu))
787 ctx = current_ctx;
788 hctx = q->mq_ops->map_queue(q, ctx->cpu);
789
790 /*
791 * preemption doesn't flush plug list, so it's possible ctx->cpu is
792 * offline now
793 */
794 spin_lock(&ctx->lock);
795 while (!list_empty(list)) {
796 struct request *rq;
797
798 rq = list_first_entry(list, struct request, queuelist);
799 list_del_init(&rq->queuelist);
800 rq->mq_ctx = ctx;
801 __blk_mq_insert_request(hctx, rq);
802 }
803 spin_unlock(&ctx->lock);
804
805 blk_mq_put_ctx(current_ctx);
806
807 blk_mq_run_hw_queue(hctx, from_schedule);
808}
809
810static int plug_ctx_cmp(void *priv, struct list_head *a, struct list_head *b)
811{
812 struct request *rqa = container_of(a, struct request, queuelist);
813 struct request *rqb = container_of(b, struct request, queuelist);
814
815 return !(rqa->mq_ctx < rqb->mq_ctx ||
816 (rqa->mq_ctx == rqb->mq_ctx &&
817 blk_rq_pos(rqa) < blk_rq_pos(rqb)));
818}
819
820void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule)
821{
822 struct blk_mq_ctx *this_ctx;
823 struct request_queue *this_q;
824 struct request *rq;
825 LIST_HEAD(list);
826 LIST_HEAD(ctx_list);
827 unsigned int depth;
828
829 list_splice_init(&plug->mq_list, &list);
830
831 list_sort(NULL, &list, plug_ctx_cmp);
832
833 this_q = NULL;
834 this_ctx = NULL;
835 depth = 0;
836
837 while (!list_empty(&list)) {
838 rq = list_entry_rq(list.next);
839 list_del_init(&rq->queuelist);
840 BUG_ON(!rq->q);
841 if (rq->mq_ctx != this_ctx) {
842 if (this_ctx) {
843 blk_mq_insert_requests(this_q, this_ctx,
844 &ctx_list, depth,
845 from_schedule);
846 }
847
848 this_ctx = rq->mq_ctx;
849 this_q = rq->q;
850 depth = 0;
851 }
852
853 depth++;
854 list_add_tail(&rq->queuelist, &ctx_list);
855 }
856
857 /*
858 * If 'this_ctx' is set, we know we have entries to complete
859 * on 'ctx_list'. Do those.
860 */
861 if (this_ctx) {
862 blk_mq_insert_requests(this_q, this_ctx, &ctx_list, depth,
863 from_schedule);
864 }
865}
866
867static void blk_mq_bio_to_request(struct request *rq, struct bio *bio)
868{
869 init_request_from_bio(rq, bio);
870 blk_account_io_start(rq, 1);
871}
872
873static void blk_mq_make_request(struct request_queue *q, struct bio *bio)
874{
875 struct blk_mq_hw_ctx *hctx;
876 struct blk_mq_ctx *ctx;
877 const int is_sync = rw_is_sync(bio->bi_rw);
878 const int is_flush_fua = bio->bi_rw & (REQ_FLUSH | REQ_FUA);
879 int rw = bio_data_dir(bio);
880 struct request *rq;
881 unsigned int use_plug, request_count = 0;
882
883 /*
884 * If we have multiple hardware queues, just go directly to
885 * one of those for sync IO.
886 */
887 use_plug = !is_flush_fua && ((q->nr_hw_queues == 1) || !is_sync);
888
889 blk_queue_bounce(q, &bio);
890
891 if (use_plug && blk_attempt_plug_merge(q, bio, &request_count))
892 return;
893
894 if (blk_mq_queue_enter(q)) {
895 bio_endio(bio, -EIO);
896 return;
897 }
898
899 ctx = blk_mq_get_ctx(q);
900 hctx = q->mq_ops->map_queue(q, ctx->cpu);
901
902 trace_block_getrq(q, bio, rw);
903 rq = __blk_mq_alloc_request(hctx, GFP_ATOMIC, false);
904 if (likely(rq))
Jens Axboe94eddfb2013-11-19 09:25:07 -0700905 blk_mq_rq_ctx_init(q, ctx, rq, rw);
Jens Axboe320ae512013-10-24 09:20:05 +0100906 else {
907 blk_mq_put_ctx(ctx);
908 trace_block_sleeprq(q, bio, rw);
909 rq = blk_mq_alloc_request_pinned(q, rw, __GFP_WAIT|GFP_ATOMIC,
910 false);
911 ctx = rq->mq_ctx;
912 hctx = q->mq_ops->map_queue(q, ctx->cpu);
913 }
914
915 hctx->queued++;
916
917 if (unlikely(is_flush_fua)) {
918 blk_mq_bio_to_request(rq, bio);
919 blk_mq_put_ctx(ctx);
920 blk_insert_flush(rq);
921 goto run_queue;
922 }
923
924 /*
925 * A task plug currently exists. Since this is completely lockless,
926 * utilize that to temporarily store requests until the task is
927 * either done or scheduled away.
928 */
929 if (use_plug) {
930 struct blk_plug *plug = current->plug;
931
932 if (plug) {
933 blk_mq_bio_to_request(rq, bio);
Shaohua Li92f399c2013-10-29 12:01:03 -0600934 if (list_empty(&plug->mq_list))
Jens Axboe320ae512013-10-24 09:20:05 +0100935 trace_block_plug(q);
936 else if (request_count >= BLK_MAX_REQUEST_COUNT) {
937 blk_flush_plug_list(plug, false);
938 trace_block_plug(q);
939 }
940 list_add_tail(&rq->queuelist, &plug->mq_list);
941 blk_mq_put_ctx(ctx);
942 return;
943 }
944 }
945
946 spin_lock(&ctx->lock);
947
948 if ((hctx->flags & BLK_MQ_F_SHOULD_MERGE) &&
949 blk_mq_attempt_merge(q, ctx, bio))
950 __blk_mq_free_request(hctx, ctx, rq);
951 else {
952 blk_mq_bio_to_request(rq, bio);
953 __blk_mq_insert_request(hctx, rq);
954 }
955
956 spin_unlock(&ctx->lock);
957 blk_mq_put_ctx(ctx);
958
959 /*
960 * For a SYNC request, send it to the hardware immediately. For an
961 * ASYNC request, just ensure that we run it later on. The latter
962 * allows for merging opportunities and more efficient dispatching.
963 */
964run_queue:
965 blk_mq_run_hw_queue(hctx, !is_sync || is_flush_fua);
966}
967
968/*
969 * Default mapping to a software queue, since we use one per CPU.
970 */
971struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q, const int cpu)
972{
973 return q->queue_hw_ctx[q->mq_map[cpu]];
974}
975EXPORT_SYMBOL(blk_mq_map_queue);
976
977struct blk_mq_hw_ctx *blk_mq_alloc_single_hw_queue(struct blk_mq_reg *reg,
978 unsigned int hctx_index)
979{
980 return kmalloc_node(sizeof(struct blk_mq_hw_ctx),
981 GFP_KERNEL | __GFP_ZERO, reg->numa_node);
982}
983EXPORT_SYMBOL(blk_mq_alloc_single_hw_queue);
984
985void blk_mq_free_single_hw_queue(struct blk_mq_hw_ctx *hctx,
986 unsigned int hctx_index)
987{
988 kfree(hctx);
989}
990EXPORT_SYMBOL(blk_mq_free_single_hw_queue);
991
992static void blk_mq_hctx_notify(void *data, unsigned long action,
993 unsigned int cpu)
994{
995 struct blk_mq_hw_ctx *hctx = data;
996 struct blk_mq_ctx *ctx;
997 LIST_HEAD(tmp);
998
999 if (action != CPU_DEAD && action != CPU_DEAD_FROZEN)
1000 return;
1001
1002 /*
1003 * Move ctx entries to new CPU, if this one is going away.
1004 */
1005 ctx = __blk_mq_get_ctx(hctx->queue, cpu);
1006
1007 spin_lock(&ctx->lock);
1008 if (!list_empty(&ctx->rq_list)) {
1009 list_splice_init(&ctx->rq_list, &tmp);
1010 clear_bit(ctx->index_hw, hctx->ctx_map);
1011 }
1012 spin_unlock(&ctx->lock);
1013
1014 if (list_empty(&tmp))
1015 return;
1016
1017 ctx = blk_mq_get_ctx(hctx->queue);
1018 spin_lock(&ctx->lock);
1019
1020 while (!list_empty(&tmp)) {
1021 struct request *rq;
1022
1023 rq = list_first_entry(&tmp, struct request, queuelist);
1024 rq->mq_ctx = ctx;
1025 list_move_tail(&rq->queuelist, &ctx->rq_list);
1026 }
1027
1028 blk_mq_hctx_mark_pending(hctx, ctx);
1029
1030 spin_unlock(&ctx->lock);
1031 blk_mq_put_ctx(ctx);
1032}
1033
1034static void blk_mq_init_hw_commands(struct blk_mq_hw_ctx *hctx,
1035 void (*init)(void *, struct blk_mq_hw_ctx *,
1036 struct request *, unsigned int),
1037 void *data)
1038{
1039 unsigned int i;
1040
1041 for (i = 0; i < hctx->queue_depth; i++) {
1042 struct request *rq = hctx->rqs[i];
1043
1044 init(data, hctx, rq, i);
1045 }
1046}
1047
1048void blk_mq_init_commands(struct request_queue *q,
1049 void (*init)(void *, struct blk_mq_hw_ctx *,
1050 struct request *, unsigned int),
1051 void *data)
1052{
1053 struct blk_mq_hw_ctx *hctx;
1054 unsigned int i;
1055
1056 queue_for_each_hw_ctx(q, hctx, i)
1057 blk_mq_init_hw_commands(hctx, init, data);
1058}
1059EXPORT_SYMBOL(blk_mq_init_commands);
1060
1061static void blk_mq_free_rq_map(struct blk_mq_hw_ctx *hctx)
1062{
1063 struct page *page;
1064
1065 while (!list_empty(&hctx->page_list)) {
Dave Hansen67534712014-01-08 20:17:46 -07001066 page = list_first_entry(&hctx->page_list, struct page, lru);
1067 list_del_init(&page->lru);
Jens Axboe320ae512013-10-24 09:20:05 +01001068 __free_pages(page, page->private);
1069 }
1070
1071 kfree(hctx->rqs);
1072
1073 if (hctx->tags)
1074 blk_mq_free_tags(hctx->tags);
1075}
1076
1077static size_t order_to_size(unsigned int order)
1078{
1079 size_t ret = PAGE_SIZE;
1080
1081 while (order--)
1082 ret *= 2;
1083
1084 return ret;
1085}
1086
1087static int blk_mq_init_rq_map(struct blk_mq_hw_ctx *hctx,
1088 unsigned int reserved_tags, int node)
1089{
1090 unsigned int i, j, entries_per_page, max_order = 4;
1091 size_t rq_size, left;
1092
1093 INIT_LIST_HEAD(&hctx->page_list);
1094
1095 hctx->rqs = kmalloc_node(hctx->queue_depth * sizeof(struct request *),
1096 GFP_KERNEL, node);
1097 if (!hctx->rqs)
1098 return -ENOMEM;
1099
1100 /*
1101 * rq_size is the size of the request plus driver payload, rounded
1102 * to the cacheline size
1103 */
1104 rq_size = round_up(sizeof(struct request) + hctx->cmd_size,
1105 cache_line_size());
1106 left = rq_size * hctx->queue_depth;
1107
1108 for (i = 0; i < hctx->queue_depth;) {
1109 int this_order = max_order;
1110 struct page *page;
1111 int to_do;
1112 void *p;
1113
1114 while (left < order_to_size(this_order - 1) && this_order)
1115 this_order--;
1116
1117 do {
1118 page = alloc_pages_node(node, GFP_KERNEL, this_order);
1119 if (page)
1120 break;
1121 if (!this_order--)
1122 break;
1123 if (order_to_size(this_order) < rq_size)
1124 break;
1125 } while (1);
1126
1127 if (!page)
1128 break;
1129
1130 page->private = this_order;
Dave Hansen67534712014-01-08 20:17:46 -07001131 list_add_tail(&page->lru, &hctx->page_list);
Jens Axboe320ae512013-10-24 09:20:05 +01001132
1133 p = page_address(page);
1134 entries_per_page = order_to_size(this_order) / rq_size;
1135 to_do = min(entries_per_page, hctx->queue_depth - i);
1136 left -= to_do * rq_size;
1137 for (j = 0; j < to_do; j++) {
1138 hctx->rqs[i] = p;
1139 blk_mq_rq_init(hctx, hctx->rqs[i]);
1140 p += rq_size;
1141 i++;
1142 }
1143 }
1144
1145 if (i < (reserved_tags + BLK_MQ_TAG_MIN))
1146 goto err_rq_map;
1147 else if (i != hctx->queue_depth) {
1148 hctx->queue_depth = i;
1149 pr_warn("%s: queue depth set to %u because of low memory\n",
1150 __func__, i);
1151 }
1152
1153 hctx->tags = blk_mq_init_tags(hctx->queue_depth, reserved_tags, node);
1154 if (!hctx->tags) {
1155err_rq_map:
1156 blk_mq_free_rq_map(hctx);
1157 return -ENOMEM;
1158 }
1159
1160 return 0;
1161}
1162
1163static int blk_mq_init_hw_queues(struct request_queue *q,
1164 struct blk_mq_reg *reg, void *driver_data)
1165{
1166 struct blk_mq_hw_ctx *hctx;
1167 unsigned int i, j;
1168
1169 /*
1170 * Initialize hardware queues
1171 */
1172 queue_for_each_hw_ctx(q, hctx, i) {
1173 unsigned int num_maps;
1174 int node;
1175
1176 node = hctx->numa_node;
1177 if (node == NUMA_NO_NODE)
1178 node = hctx->numa_node = reg->numa_node;
1179
1180 INIT_DELAYED_WORK(&hctx->delayed_work, blk_mq_work_fn);
1181 spin_lock_init(&hctx->lock);
1182 INIT_LIST_HEAD(&hctx->dispatch);
1183 hctx->queue = q;
1184 hctx->queue_num = i;
1185 hctx->flags = reg->flags;
1186 hctx->queue_depth = reg->queue_depth;
1187 hctx->cmd_size = reg->cmd_size;
1188
1189 blk_mq_init_cpu_notifier(&hctx->cpu_notifier,
1190 blk_mq_hctx_notify, hctx);
1191 blk_mq_register_cpu_notifier(&hctx->cpu_notifier);
1192
1193 if (blk_mq_init_rq_map(hctx, reg->reserved_tags, node))
1194 break;
1195
1196 /*
1197 * Allocate space for all possible cpus to avoid allocation in
1198 * runtime
1199 */
1200 hctx->ctxs = kmalloc_node(nr_cpu_ids * sizeof(void *),
1201 GFP_KERNEL, node);
1202 if (!hctx->ctxs)
1203 break;
1204
1205 num_maps = ALIGN(nr_cpu_ids, BITS_PER_LONG) / BITS_PER_LONG;
1206 hctx->ctx_map = kzalloc_node(num_maps * sizeof(unsigned long),
1207 GFP_KERNEL, node);
1208 if (!hctx->ctx_map)
1209 break;
1210
1211 hctx->nr_ctx_map = num_maps;
1212 hctx->nr_ctx = 0;
1213
1214 if (reg->ops->init_hctx &&
1215 reg->ops->init_hctx(hctx, driver_data, i))
1216 break;
1217 }
1218
1219 if (i == q->nr_hw_queues)
1220 return 0;
1221
1222 /*
1223 * Init failed
1224 */
1225 queue_for_each_hw_ctx(q, hctx, j) {
1226 if (i == j)
1227 break;
1228
1229 if (reg->ops->exit_hctx)
1230 reg->ops->exit_hctx(hctx, j);
1231
1232 blk_mq_unregister_cpu_notifier(&hctx->cpu_notifier);
1233 blk_mq_free_rq_map(hctx);
1234 kfree(hctx->ctxs);
1235 }
1236
1237 return 1;
1238}
1239
1240static void blk_mq_init_cpu_queues(struct request_queue *q,
1241 unsigned int nr_hw_queues)
1242{
1243 unsigned int i;
1244
1245 for_each_possible_cpu(i) {
1246 struct blk_mq_ctx *__ctx = per_cpu_ptr(q->queue_ctx, i);
1247 struct blk_mq_hw_ctx *hctx;
1248
1249 memset(__ctx, 0, sizeof(*__ctx));
1250 __ctx->cpu = i;
1251 spin_lock_init(&__ctx->lock);
1252 INIT_LIST_HEAD(&__ctx->rq_list);
1253 __ctx->queue = q;
1254
1255 /* If the cpu isn't online, the cpu is mapped to first hctx */
1256 hctx = q->mq_ops->map_queue(q, i);
1257 hctx->nr_ctx++;
1258
1259 if (!cpu_online(i))
1260 continue;
1261
1262 /*
1263 * Set local node, IFF we have more than one hw queue. If
1264 * not, we remain on the home node of the device
1265 */
1266 if (nr_hw_queues > 1 && hctx->numa_node == NUMA_NO_NODE)
1267 hctx->numa_node = cpu_to_node(i);
1268 }
1269}
1270
1271static void blk_mq_map_swqueue(struct request_queue *q)
1272{
1273 unsigned int i;
1274 struct blk_mq_hw_ctx *hctx;
1275 struct blk_mq_ctx *ctx;
1276
1277 queue_for_each_hw_ctx(q, hctx, i) {
1278 hctx->nr_ctx = 0;
1279 }
1280
1281 /*
1282 * Map software to hardware queues
1283 */
1284 queue_for_each_ctx(q, ctx, i) {
1285 /* If the cpu isn't online, the cpu is mapped to first hctx */
1286 hctx = q->mq_ops->map_queue(q, i);
1287 ctx->index_hw = hctx->nr_ctx;
1288 hctx->ctxs[hctx->nr_ctx++] = ctx;
1289 }
1290}
1291
1292struct request_queue *blk_mq_init_queue(struct blk_mq_reg *reg,
1293 void *driver_data)
1294{
1295 struct blk_mq_hw_ctx **hctxs;
1296 struct blk_mq_ctx *ctx;
1297 struct request_queue *q;
1298 int i;
1299
1300 if (!reg->nr_hw_queues ||
1301 !reg->ops->queue_rq || !reg->ops->map_queue ||
1302 !reg->ops->alloc_hctx || !reg->ops->free_hctx)
1303 return ERR_PTR(-EINVAL);
1304
1305 if (!reg->queue_depth)
1306 reg->queue_depth = BLK_MQ_MAX_DEPTH;
1307 else if (reg->queue_depth > BLK_MQ_MAX_DEPTH) {
1308 pr_err("blk-mq: queuedepth too large (%u)\n", reg->queue_depth);
1309 reg->queue_depth = BLK_MQ_MAX_DEPTH;
1310 }
1311
Christoph Hellwig3228f482013-10-28 13:33:58 -06001312 /*
1313 * Set aside a tag for flush requests. It will only be used while
1314 * another flush request is in progress but outside the driver.
1315 *
1316 * TODO: only allocate if flushes are supported
1317 */
1318 reg->queue_depth++;
1319 reg->reserved_tags++;
1320
Jens Axboe320ae512013-10-24 09:20:05 +01001321 if (reg->queue_depth < (reg->reserved_tags + BLK_MQ_TAG_MIN))
1322 return ERR_PTR(-EINVAL);
1323
1324 ctx = alloc_percpu(struct blk_mq_ctx);
1325 if (!ctx)
1326 return ERR_PTR(-ENOMEM);
1327
1328 hctxs = kmalloc_node(reg->nr_hw_queues * sizeof(*hctxs), GFP_KERNEL,
1329 reg->numa_node);
1330
1331 if (!hctxs)
1332 goto err_percpu;
1333
1334 for (i = 0; i < reg->nr_hw_queues; i++) {
1335 hctxs[i] = reg->ops->alloc_hctx(reg, i);
1336 if (!hctxs[i])
1337 goto err_hctxs;
1338
1339 hctxs[i]->numa_node = NUMA_NO_NODE;
1340 hctxs[i]->queue_num = i;
1341 }
1342
1343 q = blk_alloc_queue_node(GFP_KERNEL, reg->numa_node);
1344 if (!q)
1345 goto err_hctxs;
1346
1347 q->mq_map = blk_mq_make_queue_map(reg);
1348 if (!q->mq_map)
1349 goto err_map;
1350
1351 setup_timer(&q->timeout, blk_mq_rq_timer, (unsigned long) q);
1352 blk_queue_rq_timeout(q, 30000);
1353
1354 q->nr_queues = nr_cpu_ids;
1355 q->nr_hw_queues = reg->nr_hw_queues;
1356
1357 q->queue_ctx = ctx;
1358 q->queue_hw_ctx = hctxs;
1359
1360 q->mq_ops = reg->ops;
Jens Axboe94eddfb2013-11-19 09:25:07 -07001361 q->queue_flags |= QUEUE_FLAG_MQ_DEFAULT;
Jens Axboe320ae512013-10-24 09:20:05 +01001362
1363 blk_queue_make_request(q, blk_mq_make_request);
1364 blk_queue_rq_timed_out(q, reg->ops->timeout);
1365 if (reg->timeout)
1366 blk_queue_rq_timeout(q, reg->timeout);
1367
1368 blk_mq_init_flush(q);
1369 blk_mq_init_cpu_queues(q, reg->nr_hw_queues);
1370
1371 if (blk_mq_init_hw_queues(q, reg, driver_data))
1372 goto err_hw;
1373
1374 blk_mq_map_swqueue(q);
1375
1376 mutex_lock(&all_q_mutex);
1377 list_add_tail(&q->all_q_node, &all_q_list);
1378 mutex_unlock(&all_q_mutex);
1379
1380 return q;
1381err_hw:
1382 kfree(q->mq_map);
1383err_map:
1384 blk_cleanup_queue(q);
1385err_hctxs:
1386 for (i = 0; i < reg->nr_hw_queues; i++) {
1387 if (!hctxs[i])
1388 break;
1389 reg->ops->free_hctx(hctxs[i], i);
1390 }
1391 kfree(hctxs);
1392err_percpu:
1393 free_percpu(ctx);
1394 return ERR_PTR(-ENOMEM);
1395}
1396EXPORT_SYMBOL(blk_mq_init_queue);
1397
1398void blk_mq_free_queue(struct request_queue *q)
1399{
1400 struct blk_mq_hw_ctx *hctx;
1401 int i;
1402
1403 queue_for_each_hw_ctx(q, hctx, i) {
Jens Axboe320ae512013-10-24 09:20:05 +01001404 kfree(hctx->ctx_map);
1405 kfree(hctx->ctxs);
1406 blk_mq_free_rq_map(hctx);
1407 blk_mq_unregister_cpu_notifier(&hctx->cpu_notifier);
1408 if (q->mq_ops->exit_hctx)
1409 q->mq_ops->exit_hctx(hctx, i);
1410 q->mq_ops->free_hctx(hctx, i);
1411 }
1412
1413 free_percpu(q->queue_ctx);
1414 kfree(q->queue_hw_ctx);
1415 kfree(q->mq_map);
1416
1417 q->queue_ctx = NULL;
1418 q->queue_hw_ctx = NULL;
1419 q->mq_map = NULL;
1420
1421 mutex_lock(&all_q_mutex);
1422 list_del_init(&q->all_q_node);
1423 mutex_unlock(&all_q_mutex);
1424}
Jens Axboe320ae512013-10-24 09:20:05 +01001425
1426/* Basically redo blk_mq_init_queue with queue frozen */
Paul Gortmakerf618ef72013-11-14 08:26:02 -07001427static void blk_mq_queue_reinit(struct request_queue *q)
Jens Axboe320ae512013-10-24 09:20:05 +01001428{
1429 blk_mq_freeze_queue(q);
1430
1431 blk_mq_update_queue_map(q->mq_map, q->nr_hw_queues);
1432
1433 /*
1434 * redo blk_mq_init_cpu_queues and blk_mq_init_hw_queues. FIXME: maybe
1435 * we should change hctx numa_node according to new topology (this
1436 * involves free and re-allocate memory, worthy doing?)
1437 */
1438
1439 blk_mq_map_swqueue(q);
1440
1441 blk_mq_unfreeze_queue(q);
1442}
1443
Paul Gortmakerf618ef72013-11-14 08:26:02 -07001444static int blk_mq_queue_reinit_notify(struct notifier_block *nb,
1445 unsigned long action, void *hcpu)
Jens Axboe320ae512013-10-24 09:20:05 +01001446{
1447 struct request_queue *q;
1448
1449 /*
1450 * Before new mapping is established, hotadded cpu might already start
1451 * handling requests. This doesn't break anything as we map offline
1452 * CPUs to first hardware queue. We will re-init queue below to get
1453 * optimal settings.
1454 */
1455 if (action != CPU_DEAD && action != CPU_DEAD_FROZEN &&
1456 action != CPU_ONLINE && action != CPU_ONLINE_FROZEN)
1457 return NOTIFY_OK;
1458
1459 mutex_lock(&all_q_mutex);
1460 list_for_each_entry(q, &all_q_list, all_q_node)
1461 blk_mq_queue_reinit(q);
1462 mutex_unlock(&all_q_mutex);
1463 return NOTIFY_OK;
1464}
1465
1466static int __init blk_mq_init(void)
1467{
Jens Axboe320ae512013-10-24 09:20:05 +01001468 blk_mq_cpu_init();
1469
1470 /* Must be called after percpu_counter_hotcpu_callback() */
1471 hotcpu_notifier(blk_mq_queue_reinit_notify, -10);
1472
1473 return 0;
1474}
1475subsys_initcall(blk_mq_init);