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1 | #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 | |
25 | static DEFINE_MUTEX(all_q_mutex); |
26 | static LIST_HEAD(all_q_list); |
27 | |
28 | static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx); |
29 | |
30 | static 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 | */ |
42 | static struct blk_mq_ctx *blk_mq_get_ctx(struct request_queue *q) |
43 | { |
44 | return __blk_mq_get_ctx(q, get_cpu()); |
45 | } |
46 | |
47 | static 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 | */ |
55 | static 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 | */ |
69 | static 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 | |
76 | static struct request *__blk_mq_alloc_request(struct blk_mq_hw_ctx *hctx, |
77 | gfp_t gfp, 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 | |
93 | static 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, |
107 | !blk_queue_bypass(q) || blk_queue_dying(q), |
108 | *q->queue_lock); |
109 | /* inc usage with lock hold to avoid freeze_queue runs here */ |
110 | if (!ret && !blk_queue_dying(q)) |
111 | __percpu_counter_add(&q->mq_usage_counter, 1, 1000000); |
112 | else if (blk_queue_dying(q)) |
113 | ret = -ENODEV; |
114 | spin_unlock_irq(q->queue_lock); |
115 | |
116 | return ret; |
117 | } |
118 | |
119 | static void blk_mq_queue_exit(struct request_queue *q) |
120 | { |
121 | __percpu_counter_add(&q->mq_usage_counter, -1, 1000000); |
122 | } |
123 | |
124 | static 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 | |
140 | /* |
141 | * Guarantee no request is in use, so we can change any data structure of |
142 | * the queue afterward. |
143 | */ |
144 | static 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 | |
153 | if (drain) |
154 | __blk_mq_drain_queue(q); |
155 | } |
156 | |
157 | void blk_mq_drain_queue(struct request_queue *q) |
158 | { |
159 | __blk_mq_drain_queue(q); |
160 | } |
161 | |
162 | static 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 | |
177 | bool blk_mq_can_queue(struct blk_mq_hw_ctx *hctx) |
178 | { |
179 | return blk_mq_has_free_tags(hctx->tags); |
180 | } |
181 | EXPORT_SYMBOL(blk_mq_can_queue); |
182 | |
183 | static void blk_mq_rq_ctx_init(struct request_queue *q, struct blk_mq_ctx *ctx, |
184 | struct request *rq, unsigned int rw_flags) |
185 | { |
186 | if (blk_queue_io_stat(q)) |
187 | rw_flags |= REQ_IO_STAT; |
188 | |
189 | rq->mq_ctx = ctx; |
190 | rq->cmd_flags = rw_flags; |
191 | rq->start_time = jiffies; |
192 | set_start_time_ns(rq); |
193 | ctx->rq_dispatched[rw_is_sync(rw_flags)]++; |
194 | } |
195 | |
196 | static struct request *blk_mq_alloc_request_pinned(struct request_queue *q, |
197 | int rw, gfp_t gfp, |
198 | bool reserved) |
199 | { |
200 | struct request *rq; |
201 | |
202 | do { |
203 | struct blk_mq_ctx *ctx = blk_mq_get_ctx(q); |
204 | struct blk_mq_hw_ctx *hctx = q->mq_ops->map_queue(q, ctx->cpu); |
205 | |
206 | rq = __blk_mq_alloc_request(hctx, gfp & ~__GFP_WAIT, reserved); |
207 | if (rq) { |
208 | blk_mq_rq_ctx_init(q, ctx, rq, rw); |
209 | break; |
210 | } |
211 | |
212 | blk_mq_put_ctx(ctx); |
213 | if (!(gfp & __GFP_WAIT)) |
214 | break; |
215 | |
216 | __blk_mq_run_hw_queue(hctx); |
217 | blk_mq_wait_for_tags(hctx->tags); |
218 | } while (1); |
219 | |
220 | return rq; |
221 | } |
222 | |
223 | struct request *blk_mq_alloc_request(struct request_queue *q, int rw, gfp_t gfp) |
224 | { |
225 | struct request *rq; |
226 | |
227 | if (blk_mq_queue_enter(q)) |
228 | return NULL; |
229 | |
230 | rq = blk_mq_alloc_request_pinned(q, rw, gfp, false); |
231 | if (rq) |
232 | blk_mq_put_ctx(rq->mq_ctx); |
233 | return rq; |
234 | } |
235 | |
236 | struct request *blk_mq_alloc_reserved_request(struct request_queue *q, int rw, |
237 | gfp_t gfp) |
238 | { |
239 | struct request *rq; |
240 | |
241 | if (blk_mq_queue_enter(q)) |
242 | return NULL; |
243 | |
244 | rq = blk_mq_alloc_request_pinned(q, rw, gfp, true); |
245 | if (rq) |
246 | blk_mq_put_ctx(rq->mq_ctx); |
247 | return rq; |
248 | } |
249 | EXPORT_SYMBOL(blk_mq_alloc_reserved_request); |
250 | |
251 | /* |
252 | * Re-init and set pdu, if we have it |
253 | */ |
254 | void blk_mq_rq_init(struct blk_mq_hw_ctx *hctx, struct request *rq) |
255 | { |
256 | blk_rq_init(hctx->queue, rq); |
257 | |
258 | if (hctx->cmd_size) |
259 | rq->special = blk_mq_rq_to_pdu(rq); |
260 | } |
261 | |
262 | static void __blk_mq_free_request(struct blk_mq_hw_ctx *hctx, |
263 | struct blk_mq_ctx *ctx, struct request *rq) |
264 | { |
265 | const int tag = rq->tag; |
266 | struct request_queue *q = rq->q; |
267 | |
268 | blk_mq_rq_init(hctx, rq); |
269 | blk_mq_put_tag(hctx->tags, tag); |
270 | |
271 | blk_mq_queue_exit(q); |
272 | } |
273 | |
274 | void blk_mq_free_request(struct request *rq) |
275 | { |
276 | struct blk_mq_ctx *ctx = rq->mq_ctx; |
277 | struct blk_mq_hw_ctx *hctx; |
278 | struct request_queue *q = rq->q; |
279 | |
280 | ctx->rq_completed[rq_is_sync(rq)]++; |
281 | |
282 | hctx = q->mq_ops->map_queue(q, ctx->cpu); |
283 | __blk_mq_free_request(hctx, ctx, rq); |
284 | } |
285 | |
286 | bool blk_mq_end_io_partial(struct request *rq, int error, unsigned int nr_bytes) |
287 | { |
288 | if (blk_update_request(rq, error, blk_rq_bytes(rq))) |
289 | return true; |
290 | |
291 | blk_account_io_done(rq); |
292 | |
293 | if (rq->end_io) |
294 | rq->end_io(rq, error); |
295 | else |
296 | blk_mq_free_request(rq); |
297 | return false; |
298 | } |
299 | EXPORT_SYMBOL(blk_mq_end_io_partial); |
300 | |
301 | static void __blk_mq_complete_request_remote(void *data) |
302 | { |
303 | struct request *rq = data; |
304 | |
305 | rq->q->softirq_done_fn(rq); |
306 | } |
307 | |
308 | void __blk_mq_complete_request(struct request *rq) |
309 | { |
310 | struct blk_mq_ctx *ctx = rq->mq_ctx; |
311 | int cpu; |
312 | |
313 | if (!ctx->ipi_redirect) { |
314 | rq->q->softirq_done_fn(rq); |
315 | return; |
316 | } |
317 | |
318 | cpu = get_cpu(); |
319 | if (cpu != ctx->cpu && cpu_online(ctx->cpu)) { |
320 | rq->csd.func = __blk_mq_complete_request_remote; |
321 | rq->csd.info = rq; |
322 | rq->csd.flags = 0; |
323 | smp_call_function_single_async(ctx->cpu, &rq->csd); |
324 | } else { |
325 | rq->q->softirq_done_fn(rq); |
326 | } |
327 | put_cpu(); |
328 | } |
329 | |
330 | /** |
331 | * blk_mq_complete_request - end I/O on a request |
332 | * @rq: the request being processed |
333 | * |
334 | * Description: |
335 | * Ends all I/O on a request. It does not handle partial completions. |
336 | * The actual completion happens out-of-order, through a IPI handler. |
337 | **/ |
338 | void blk_mq_complete_request(struct request *rq) |
339 | { |
340 | if (unlikely(blk_should_fake_timeout(rq->q))) |
341 | return; |
342 | if (!blk_mark_rq_complete(rq)) |
343 | __blk_mq_complete_request(rq); |
344 | } |
345 | EXPORT_SYMBOL(blk_mq_complete_request); |
346 | |
347 | static void blk_mq_start_request(struct request *rq, bool last) |
348 | { |
349 | struct request_queue *q = rq->q; |
350 | |
351 | trace_block_rq_issue(q, rq); |
352 | |
353 | /* |
354 | * Just mark start time and set the started bit. Due to memory |
355 | * ordering, we know we'll see the correct deadline as long as |
356 | * REQ_ATOMIC_STARTED is seen. |
357 | */ |
358 | rq->deadline = jiffies + q->rq_timeout; |
359 | set_bit(REQ_ATOM_STARTED, &rq->atomic_flags); |
360 | |
361 | if (q->dma_drain_size && blk_rq_bytes(rq)) { |
362 | /* |
363 | * Make sure space for the drain appears. We know we can do |
364 | * this because max_hw_segments has been adjusted to be one |
365 | * fewer than the device can handle. |
366 | */ |
367 | rq->nr_phys_segments++; |
368 | } |
369 | |
370 | /* |
371 | * Flag the last request in the series so that drivers know when IO |
372 | * should be kicked off, if they don't do it on a per-request basis. |
373 | * |
374 | * Note: the flag isn't the only condition drivers should do kick off. |
375 | * If drive is busy, the last request might not have the bit set. |
376 | */ |
377 | if (last) |
378 | rq->cmd_flags |= REQ_END; |
379 | } |
380 | |
381 | static void blk_mq_requeue_request(struct request *rq) |
382 | { |
383 | struct request_queue *q = rq->q; |
384 | |
385 | trace_block_rq_requeue(q, rq); |
386 | clear_bit(REQ_ATOM_STARTED, &rq->atomic_flags); |
387 | |
388 | rq->cmd_flags &= ~REQ_END; |
389 | |
390 | if (q->dma_drain_size && blk_rq_bytes(rq)) |
391 | rq->nr_phys_segments--; |
392 | } |
393 | |
394 | struct blk_mq_timeout_data { |
395 | struct blk_mq_hw_ctx *hctx; |
396 | unsigned long *next; |
397 | unsigned int *next_set; |
398 | }; |
399 | |
400 | static void blk_mq_timeout_check(void *__data, unsigned long *free_tags) |
401 | { |
402 | struct blk_mq_timeout_data *data = __data; |
403 | struct blk_mq_hw_ctx *hctx = data->hctx; |
404 | unsigned int tag; |
405 | |
406 | /* It may not be in flight yet (this is where |
407 | * the REQ_ATOMIC_STARTED flag comes in). The requests are |
408 | * statically allocated, so we know it's always safe to access the |
409 | * memory associated with a bit offset into ->rqs[]. |
410 | */ |
411 | tag = 0; |
412 | do { |
413 | struct request *rq; |
414 | |
415 | tag = find_next_zero_bit(free_tags, hctx->queue_depth, tag); |
416 | if (tag >= hctx->queue_depth) |
417 | break; |
418 | |
419 | rq = hctx->rqs[tag++]; |
420 | |
421 | if (!test_bit(REQ_ATOM_STARTED, &rq->atomic_flags)) |
422 | continue; |
423 | |
424 | blk_rq_check_expired(rq, data->next, data->next_set); |
425 | } while (1); |
426 | } |
427 | |
428 | static void blk_mq_hw_ctx_check_timeout(struct blk_mq_hw_ctx *hctx, |
429 | unsigned long *next, |
430 | unsigned int *next_set) |
431 | { |
432 | struct blk_mq_timeout_data data = { |
433 | .hctx = hctx, |
434 | .next = next, |
435 | .next_set = next_set, |
436 | }; |
437 | |
438 | /* |
439 | * Ask the tagging code to iterate busy requests, so we can |
440 | * check them for timeout. |
441 | */ |
442 | blk_mq_tag_busy_iter(hctx->tags, blk_mq_timeout_check, &data); |
443 | } |
444 | |
445 | static void blk_mq_rq_timer(unsigned long data) |
446 | { |
447 | struct request_queue *q = (struct request_queue *) data; |
448 | struct blk_mq_hw_ctx *hctx; |
449 | unsigned long next = 0; |
450 | int i, next_set = 0; |
451 | |
452 | queue_for_each_hw_ctx(q, hctx, i) |
453 | blk_mq_hw_ctx_check_timeout(hctx, &next, &next_set); |
454 | |
455 | if (next_set) |
456 | mod_timer(&q->timeout, round_jiffies_up(next)); |
457 | } |
458 | |
459 | /* |
460 | * Reverse check our software queue for entries that we could potentially |
461 | * merge with. Currently includes a hand-wavy stop count of 8, to not spend |
462 | * too much time checking for merges. |
463 | */ |
464 | static bool blk_mq_attempt_merge(struct request_queue *q, |
465 | struct blk_mq_ctx *ctx, struct bio *bio) |
466 | { |
467 | struct request *rq; |
468 | int checked = 8; |
469 | |
470 | list_for_each_entry_reverse(rq, &ctx->rq_list, queuelist) { |
471 | int el_ret; |
472 | |
473 | if (!checked--) |
474 | break; |
475 | |
476 | if (!blk_rq_merge_ok(rq, bio)) |
477 | continue; |
478 | |
479 | el_ret = blk_try_merge(rq, bio); |
480 | if (el_ret == ELEVATOR_BACK_MERGE) { |
481 | if (bio_attempt_back_merge(q, rq, bio)) { |
482 | ctx->rq_merged++; |
483 | return true; |
484 | } |
485 | break; |
486 | } else if (el_ret == ELEVATOR_FRONT_MERGE) { |
487 | if (bio_attempt_front_merge(q, rq, bio)) { |
488 | ctx->rq_merged++; |
489 | return true; |
490 | } |
491 | break; |
492 | } |
493 | } |
494 | |
495 | return false; |
496 | } |
497 | |
498 | void blk_mq_add_timer(struct request *rq) |
499 | { |
500 | __blk_add_timer(rq, NULL); |
501 | } |
502 | |
503 | /* |
504 | * Run this hardware queue, pulling any software queues mapped to it in. |
505 | * Note that this function currently has various problems around ordering |
506 | * of IO. In particular, we'd like FIFO behaviour on handling existing |
507 | * items on the hctx->dispatch list. Ignore that for now. |
508 | */ |
509 | static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx) |
510 | { |
511 | struct request_queue *q = hctx->queue; |
512 | struct blk_mq_ctx *ctx; |
513 | struct request *rq; |
514 | LIST_HEAD(rq_list); |
515 | int bit, queued; |
516 | |
517 | if (unlikely(test_bit(BLK_MQ_S_STOPPED, &hctx->state))) |
518 | return; |
519 | |
520 | hctx->run++; |
521 | |
522 | /* |
523 | * Touch any software queue that has pending entries. |
524 | */ |
525 | for_each_set_bit(bit, hctx->ctx_map, hctx->nr_ctx) { |
526 | clear_bit(bit, hctx->ctx_map); |
527 | ctx = hctx->ctxs[bit]; |
528 | BUG_ON(bit != ctx->index_hw); |
529 | |
530 | spin_lock(&ctx->lock); |
531 | list_splice_tail_init(&ctx->rq_list, &rq_list); |
532 | spin_unlock(&ctx->lock); |
533 | } |
534 | |
535 | /* |
536 | * If we have previous entries on our dispatch list, grab them |
537 | * and stuff them at the front for more fair dispatch. |
538 | */ |
539 | if (!list_empty_careful(&hctx->dispatch)) { |
540 | spin_lock(&hctx->lock); |
541 | if (!list_empty(&hctx->dispatch)) |
542 | list_splice_init(&hctx->dispatch, &rq_list); |
543 | spin_unlock(&hctx->lock); |
544 | } |
545 | |
546 | /* |
547 | * Delete and return all entries from our dispatch list |
548 | */ |
549 | queued = 0; |
550 | |
551 | /* |
552 | * Now process all the entries, sending them to the driver. |
553 | */ |
554 | while (!list_empty(&rq_list)) { |
555 | int ret; |
556 | |
557 | rq = list_first_entry(&rq_list, struct request, queuelist); |
558 | list_del_init(&rq->queuelist); |
559 | |
560 | blk_mq_start_request(rq, list_empty(&rq_list)); |
561 | |
562 | ret = q->mq_ops->queue_rq(hctx, rq); |
563 | switch (ret) { |
564 | case BLK_MQ_RQ_QUEUE_OK: |
565 | queued++; |
566 | continue; |
567 | case BLK_MQ_RQ_QUEUE_BUSY: |
568 | /* |
569 | * FIXME: we should have a mechanism to stop the queue |
570 | * like blk_stop_queue, otherwise we will waste cpu |
571 | * time |
572 | */ |
573 | list_add(&rq->queuelist, &rq_list); |
574 | blk_mq_requeue_request(rq); |
575 | break; |
576 | default: |
577 | pr_err("blk-mq: bad return on queue: %d\n", ret); |
578 | case BLK_MQ_RQ_QUEUE_ERROR: |
579 | rq->errors = -EIO; |
580 | blk_mq_end_io(rq, rq->errors); |
581 | break; |
582 | } |
583 | |
584 | if (ret == BLK_MQ_RQ_QUEUE_BUSY) |
585 | break; |
586 | } |
587 | |
588 | if (!queued) |
589 | hctx->dispatched[0]++; |
590 | else if (queued < (1 << (BLK_MQ_MAX_DISPATCH_ORDER - 1))) |
591 | hctx->dispatched[ilog2(queued) + 1]++; |
592 | |
593 | /* |
594 | * Any items that need requeuing? Stuff them into hctx->dispatch, |
595 | * that is where we will continue on next queue run. |
596 | */ |
597 | if (!list_empty(&rq_list)) { |
598 | spin_lock(&hctx->lock); |
599 | list_splice(&rq_list, &hctx->dispatch); |
600 | spin_unlock(&hctx->lock); |
601 | } |
602 | } |
603 | |
604 | void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async) |
605 | { |
606 | if (unlikely(test_bit(BLK_MQ_S_STOPPED, &hctx->state))) |
607 | return; |
608 | |
609 | if (!async) |
610 | __blk_mq_run_hw_queue(hctx); |
611 | else { |
612 | struct request_queue *q = hctx->queue; |
613 | |
614 | kblockd_schedule_delayed_work(q, &hctx->delayed_work, 0); |
615 | } |
616 | } |
617 | |
618 | void blk_mq_run_queues(struct request_queue *q, bool async) |
619 | { |
620 | struct blk_mq_hw_ctx *hctx; |
621 | int i; |
622 | |
623 | queue_for_each_hw_ctx(q, hctx, i) { |
624 | if ((!blk_mq_hctx_has_pending(hctx) && |
625 | list_empty_careful(&hctx->dispatch)) || |
626 | test_bit(BLK_MQ_S_STOPPED, &hctx->state)) |
627 | continue; |
628 | |
629 | blk_mq_run_hw_queue(hctx, async); |
630 | } |
631 | } |
632 | EXPORT_SYMBOL(blk_mq_run_queues); |
633 | |
634 | void blk_mq_stop_hw_queue(struct blk_mq_hw_ctx *hctx) |
635 | { |
636 | cancel_delayed_work(&hctx->delayed_work); |
637 | set_bit(BLK_MQ_S_STOPPED, &hctx->state); |
638 | } |
639 | EXPORT_SYMBOL(blk_mq_stop_hw_queue); |
640 | |
641 | void blk_mq_stop_hw_queues(struct request_queue *q) |
642 | { |
643 | struct blk_mq_hw_ctx *hctx; |
644 | int i; |
645 | |
646 | queue_for_each_hw_ctx(q, hctx, i) |
647 | blk_mq_stop_hw_queue(hctx); |
648 | } |
649 | EXPORT_SYMBOL(blk_mq_stop_hw_queues); |
650 | |
651 | void blk_mq_start_hw_queue(struct blk_mq_hw_ctx *hctx) |
652 | { |
653 | clear_bit(BLK_MQ_S_STOPPED, &hctx->state); |
654 | __blk_mq_run_hw_queue(hctx); |
655 | } |
656 | EXPORT_SYMBOL(blk_mq_start_hw_queue); |
657 | |
658 | void blk_mq_start_stopped_hw_queues(struct request_queue *q) |
659 | { |
660 | struct blk_mq_hw_ctx *hctx; |
661 | int i; |
662 | |
663 | queue_for_each_hw_ctx(q, hctx, i) { |
664 | if (!test_bit(BLK_MQ_S_STOPPED, &hctx->state)) |
665 | continue; |
666 | |
667 | clear_bit(BLK_MQ_S_STOPPED, &hctx->state); |
668 | blk_mq_run_hw_queue(hctx, true); |
669 | } |
670 | } |
671 | EXPORT_SYMBOL(blk_mq_start_stopped_hw_queues); |
672 | |
673 | static void blk_mq_work_fn(struct work_struct *work) |
674 | { |
675 | struct blk_mq_hw_ctx *hctx; |
676 | |
677 | hctx = container_of(work, struct blk_mq_hw_ctx, delayed_work.work); |
678 | __blk_mq_run_hw_queue(hctx); |
679 | } |
680 | |
681 | static void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, |
682 | struct request *rq, bool at_head) |
683 | { |
684 | struct blk_mq_ctx *ctx = rq->mq_ctx; |
685 | |
686 | trace_block_rq_insert(hctx->queue, rq); |
687 | |
688 | if (at_head) |
689 | list_add(&rq->queuelist, &ctx->rq_list); |
690 | else |
691 | list_add_tail(&rq->queuelist, &ctx->rq_list); |
692 | blk_mq_hctx_mark_pending(hctx, ctx); |
693 | |
694 | /* |
695 | * We do this early, to ensure we are on the right CPU. |
696 | */ |
697 | blk_mq_add_timer(rq); |
698 | } |
699 | |
700 | void blk_mq_insert_request(struct request *rq, bool at_head, bool run_queue, |
701 | bool async) |
702 | { |
703 | struct request_queue *q = rq->q; |
704 | struct blk_mq_hw_ctx *hctx; |
705 | struct blk_mq_ctx *ctx = rq->mq_ctx, *current_ctx; |
706 | |
707 | current_ctx = blk_mq_get_ctx(q); |
708 | if (!cpu_online(ctx->cpu)) |
709 | rq->mq_ctx = ctx = current_ctx; |
710 | |
711 | hctx = q->mq_ops->map_queue(q, ctx->cpu); |
712 | |
713 | if (rq->cmd_flags & (REQ_FLUSH | REQ_FUA) && |
714 | !(rq->cmd_flags & (REQ_FLUSH_SEQ))) { |
715 | blk_insert_flush(rq); |
716 | } else { |
717 | spin_lock(&ctx->lock); |
718 | __blk_mq_insert_request(hctx, rq, at_head); |
719 | spin_unlock(&ctx->lock); |
720 | } |
721 | |
722 | blk_mq_put_ctx(current_ctx); |
723 | |
724 | if (run_queue) |
725 | blk_mq_run_hw_queue(hctx, async); |
726 | } |
727 | |
728 | static void blk_mq_insert_requests(struct request_queue *q, |
729 | struct blk_mq_ctx *ctx, |
730 | struct list_head *list, |
731 | int depth, |
732 | bool from_schedule) |
733 | |
734 | { |
735 | struct blk_mq_hw_ctx *hctx; |
736 | struct blk_mq_ctx *current_ctx; |
737 | |
738 | trace_block_unplug(q, depth, !from_schedule); |
739 | |
740 | current_ctx = blk_mq_get_ctx(q); |
741 | |
742 | if (!cpu_online(ctx->cpu)) |
743 | ctx = current_ctx; |
744 | hctx = q->mq_ops->map_queue(q, ctx->cpu); |
745 | |
746 | /* |
747 | * preemption doesn't flush plug list, so it's possible ctx->cpu is |
748 | * offline now |
749 | */ |
750 | spin_lock(&ctx->lock); |
751 | while (!list_empty(list)) { |
752 | struct request *rq; |
753 | |
754 | rq = list_first_entry(list, struct request, queuelist); |
755 | list_del_init(&rq->queuelist); |
756 | rq->mq_ctx = ctx; |
757 | __blk_mq_insert_request(hctx, rq, false); |
758 | } |
759 | spin_unlock(&ctx->lock); |
760 | |
761 | blk_mq_put_ctx(current_ctx); |
762 | |
763 | blk_mq_run_hw_queue(hctx, from_schedule); |
764 | } |
765 | |
766 | static int plug_ctx_cmp(void *priv, struct list_head *a, struct list_head *b) |
767 | { |
768 | struct request *rqa = container_of(a, struct request, queuelist); |
769 | struct request *rqb = container_of(b, struct request, queuelist); |
770 | |
771 | return !(rqa->mq_ctx < rqb->mq_ctx || |
772 | (rqa->mq_ctx == rqb->mq_ctx && |
773 | blk_rq_pos(rqa) < blk_rq_pos(rqb))); |
774 | } |
775 | |
776 | void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule) |
777 | { |
778 | struct blk_mq_ctx *this_ctx; |
779 | struct request_queue *this_q; |
780 | struct request *rq; |
781 | LIST_HEAD(list); |
782 | LIST_HEAD(ctx_list); |
783 | unsigned int depth; |
784 | |
785 | list_splice_init(&plug->mq_list, &list); |
786 | |
787 | list_sort(NULL, &list, plug_ctx_cmp); |
788 | |
789 | this_q = NULL; |
790 | this_ctx = NULL; |
791 | depth = 0; |
792 | |
793 | while (!list_empty(&list)) { |
794 | rq = list_entry_rq(list.next); |
795 | list_del_init(&rq->queuelist); |
796 | BUG_ON(!rq->q); |
797 | if (rq->mq_ctx != this_ctx) { |
798 | if (this_ctx) { |
799 | blk_mq_insert_requests(this_q, this_ctx, |
800 | &ctx_list, depth, |
801 | from_schedule); |
802 | } |
803 | |
804 | this_ctx = rq->mq_ctx; |
805 | this_q = rq->q; |
806 | depth = 0; |
807 | } |
808 | |
809 | depth++; |
810 | list_add_tail(&rq->queuelist, &ctx_list); |
811 | } |
812 | |
813 | /* |
814 | * If 'this_ctx' is set, we know we have entries to complete |
815 | * on 'ctx_list'. Do those. |
816 | */ |
817 | if (this_ctx) { |
818 | blk_mq_insert_requests(this_q, this_ctx, &ctx_list, depth, |
819 | from_schedule); |
820 | } |
821 | } |
822 | |
823 | static void blk_mq_bio_to_request(struct request *rq, struct bio *bio) |
824 | { |
825 | init_request_from_bio(rq, bio); |
826 | blk_account_io_start(rq, 1); |
827 | } |
828 | |
829 | static void blk_mq_make_request(struct request_queue *q, struct bio *bio) |
830 | { |
831 | struct blk_mq_hw_ctx *hctx; |
832 | struct blk_mq_ctx *ctx; |
833 | const int is_sync = rw_is_sync(bio->bi_rw); |
834 | const int is_flush_fua = bio->bi_rw & (REQ_FLUSH | REQ_FUA); |
835 | int rw = bio_data_dir(bio); |
836 | struct request *rq; |
837 | unsigned int use_plug, request_count = 0; |
838 | |
839 | /* |
840 | * If we have multiple hardware queues, just go directly to |
841 | * one of those for sync IO. |
842 | */ |
843 | use_plug = !is_flush_fua && ((q->nr_hw_queues == 1) || !is_sync); |
844 | |
845 | blk_queue_bounce(q, &bio); |
846 | |
847 | if (bio_integrity_enabled(bio) && bio_integrity_prep(bio)) { |
848 | bio_endio(bio, -EIO); |
849 | return; |
850 | } |
851 | |
852 | if (use_plug && blk_attempt_plug_merge(q, bio, &request_count)) |
853 | return; |
854 | |
855 | if (blk_mq_queue_enter(q)) { |
856 | bio_endio(bio, -EIO); |
857 | return; |
858 | } |
859 | |
860 | ctx = blk_mq_get_ctx(q); |
861 | hctx = q->mq_ops->map_queue(q, ctx->cpu); |
862 | |
863 | if (is_sync) |
864 | rw |= REQ_SYNC; |
865 | trace_block_getrq(q, bio, rw); |
866 | rq = __blk_mq_alloc_request(hctx, GFP_ATOMIC, false); |
867 | if (likely(rq)) |
868 | blk_mq_rq_ctx_init(q, ctx, rq, rw); |
869 | else { |
870 | blk_mq_put_ctx(ctx); |
871 | trace_block_sleeprq(q, bio, rw); |
872 | rq = blk_mq_alloc_request_pinned(q, rw, __GFP_WAIT|GFP_ATOMIC, |
873 | false); |
874 | ctx = rq->mq_ctx; |
875 | hctx = q->mq_ops->map_queue(q, ctx->cpu); |
876 | } |
877 | |
878 | hctx->queued++; |
879 | |
880 | if (unlikely(is_flush_fua)) { |
881 | blk_mq_bio_to_request(rq, bio); |
882 | blk_mq_put_ctx(ctx); |
883 | blk_insert_flush(rq); |
884 | goto run_queue; |
885 | } |
886 | |
887 | /* |
888 | * A task plug currently exists. Since this is completely lockless, |
889 | * utilize that to temporarily store requests until the task is |
890 | * either done or scheduled away. |
891 | */ |
892 | if (use_plug) { |
893 | struct blk_plug *plug = current->plug; |
894 | |
895 | if (plug) { |
896 | blk_mq_bio_to_request(rq, bio); |
897 | if (list_empty(&plug->mq_list)) |
898 | trace_block_plug(q); |
899 | else if (request_count >= BLK_MAX_REQUEST_COUNT) { |
900 | blk_flush_plug_list(plug, false); |
901 | trace_block_plug(q); |
902 | } |
903 | list_add_tail(&rq->queuelist, &plug->mq_list); |
904 | blk_mq_put_ctx(ctx); |
905 | return; |
906 | } |
907 | } |
908 | |
909 | spin_lock(&ctx->lock); |
910 | |
911 | if ((hctx->flags & BLK_MQ_F_SHOULD_MERGE) && |
912 | blk_mq_attempt_merge(q, ctx, bio)) |
913 | __blk_mq_free_request(hctx, ctx, rq); |
914 | else { |
915 | blk_mq_bio_to_request(rq, bio); |
916 | __blk_mq_insert_request(hctx, rq, false); |
917 | } |
918 | |
919 | spin_unlock(&ctx->lock); |
920 | blk_mq_put_ctx(ctx); |
921 | |
922 | /* |
923 | * For a SYNC request, send it to the hardware immediately. For an |
924 | * ASYNC request, just ensure that we run it later on. The latter |
925 | * allows for merging opportunities and more efficient dispatching. |
926 | */ |
927 | run_queue: |
928 | blk_mq_run_hw_queue(hctx, !is_sync || is_flush_fua); |
929 | } |
930 | |
931 | /* |
932 | * Default mapping to a software queue, since we use one per CPU. |
933 | */ |
934 | struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q, const int cpu) |
935 | { |
936 | return q->queue_hw_ctx[q->mq_map[cpu]]; |
937 | } |
938 | EXPORT_SYMBOL(blk_mq_map_queue); |
939 | |
940 | struct blk_mq_hw_ctx *blk_mq_alloc_single_hw_queue(struct blk_mq_reg *reg, |
941 | unsigned int hctx_index) |
942 | { |
943 | return kmalloc_node(sizeof(struct blk_mq_hw_ctx), |
944 | GFP_KERNEL | __GFP_ZERO, reg->numa_node); |
945 | } |
946 | EXPORT_SYMBOL(blk_mq_alloc_single_hw_queue); |
947 | |
948 | void blk_mq_free_single_hw_queue(struct blk_mq_hw_ctx *hctx, |
949 | unsigned int hctx_index) |
950 | { |
951 | kfree(hctx); |
952 | } |
953 | EXPORT_SYMBOL(blk_mq_free_single_hw_queue); |
954 | |
955 | static void blk_mq_hctx_notify(void *data, unsigned long action, |
956 | unsigned int cpu) |
957 | { |
958 | struct blk_mq_hw_ctx *hctx = data; |
959 | struct request_queue *q = hctx->queue; |
960 | struct blk_mq_ctx *ctx; |
961 | LIST_HEAD(tmp); |
962 | |
963 | if (action != CPU_DEAD && action != CPU_DEAD_FROZEN) |
964 | return; |
965 | |
966 | /* |
967 | * Move ctx entries to new CPU, if this one is going away. |
968 | */ |
969 | ctx = __blk_mq_get_ctx(q, cpu); |
970 | |
971 | spin_lock(&ctx->lock); |
972 | if (!list_empty(&ctx->rq_list)) { |
973 | list_splice_init(&ctx->rq_list, &tmp); |
974 | clear_bit(ctx->index_hw, hctx->ctx_map); |
975 | } |
976 | spin_unlock(&ctx->lock); |
977 | |
978 | if (list_empty(&tmp)) |
979 | return; |
980 | |
981 | ctx = blk_mq_get_ctx(q); |
982 | spin_lock(&ctx->lock); |
983 | |
984 | while (!list_empty(&tmp)) { |
985 | struct request *rq; |
986 | |
987 | rq = list_first_entry(&tmp, struct request, queuelist); |
988 | rq->mq_ctx = ctx; |
989 | list_move_tail(&rq->queuelist, &ctx->rq_list); |
990 | } |
991 | |
992 | hctx = q->mq_ops->map_queue(q, ctx->cpu); |
993 | blk_mq_hctx_mark_pending(hctx, ctx); |
994 | |
995 | spin_unlock(&ctx->lock); |
996 | blk_mq_put_ctx(ctx); |
997 | |
998 | blk_mq_run_hw_queue(hctx, true); |
999 | } |
1000 | |
1001 | static int blk_mq_init_hw_commands(struct blk_mq_hw_ctx *hctx, |
1002 | int (*init)(void *, struct blk_mq_hw_ctx *, |
1003 | struct request *, unsigned int), |
1004 | void *data) |
1005 | { |
1006 | unsigned int i; |
1007 | int ret = 0; |
1008 | |
1009 | for (i = 0; i < hctx->queue_depth; i++) { |
1010 | struct request *rq = hctx->rqs[i]; |
1011 | |
1012 | ret = init(data, hctx, rq, i); |
1013 | if (ret) |
1014 | break; |
1015 | } |
1016 | |
1017 | return ret; |
1018 | } |
1019 | |
1020 | int blk_mq_init_commands(struct request_queue *q, |
1021 | int (*init)(void *, struct blk_mq_hw_ctx *, |
1022 | struct request *, unsigned int), |
1023 | void *data) |
1024 | { |
1025 | struct blk_mq_hw_ctx *hctx; |
1026 | unsigned int i; |
1027 | int ret = 0; |
1028 | |
1029 | queue_for_each_hw_ctx(q, hctx, i) { |
1030 | ret = blk_mq_init_hw_commands(hctx, init, data); |
1031 | if (ret) |
1032 | break; |
1033 | } |
1034 | |
1035 | return ret; |
1036 | } |
1037 | EXPORT_SYMBOL(blk_mq_init_commands); |
1038 | |
1039 | static void blk_mq_free_hw_commands(struct blk_mq_hw_ctx *hctx, |
1040 | void (*free)(void *, struct blk_mq_hw_ctx *, |
1041 | struct request *, unsigned int), |
1042 | void *data) |
1043 | { |
1044 | unsigned int i; |
1045 | |
1046 | for (i = 0; i < hctx->queue_depth; i++) { |
1047 | struct request *rq = hctx->rqs[i]; |
1048 | |
1049 | free(data, hctx, rq, i); |
1050 | } |
1051 | } |
1052 | |
1053 | void blk_mq_free_commands(struct request_queue *q, |
1054 | void (*free)(void *, struct blk_mq_hw_ctx *, |
1055 | struct request *, unsigned int), |
1056 | void *data) |
1057 | { |
1058 | struct blk_mq_hw_ctx *hctx; |
1059 | unsigned int i; |
1060 | |
1061 | queue_for_each_hw_ctx(q, hctx, i) |
1062 | blk_mq_free_hw_commands(hctx, free, data); |
1063 | } |
1064 | EXPORT_SYMBOL(blk_mq_free_commands); |
1065 | |
1066 | static void blk_mq_free_rq_map(struct blk_mq_hw_ctx *hctx) |
1067 | { |
1068 | struct page *page; |
1069 | |
1070 | while (!list_empty(&hctx->page_list)) { |
1071 | page = list_first_entry(&hctx->page_list, struct page, lru); |
1072 | list_del_init(&page->lru); |
1073 | __free_pages(page, page->private); |
1074 | } |
1075 | |
1076 | kfree(hctx->rqs); |
1077 | |
1078 | if (hctx->tags) |
1079 | blk_mq_free_tags(hctx->tags); |
1080 | } |
1081 | |
1082 | static size_t order_to_size(unsigned int order) |
1083 | { |
1084 | size_t ret = PAGE_SIZE; |
1085 | |
1086 | while (order--) |
1087 | ret *= 2; |
1088 | |
1089 | return ret; |
1090 | } |
1091 | |
1092 | static int blk_mq_init_rq_map(struct blk_mq_hw_ctx *hctx, |
1093 | unsigned int reserved_tags, int node) |
1094 | { |
1095 | unsigned int i, j, entries_per_page, max_order = 4; |
1096 | size_t rq_size, left; |
1097 | |
1098 | INIT_LIST_HEAD(&hctx->page_list); |
1099 | |
1100 | hctx->rqs = kmalloc_node(hctx->queue_depth * sizeof(struct request *), |
1101 | GFP_KERNEL, node); |
1102 | if (!hctx->rqs) |
1103 | return -ENOMEM; |
1104 | |
1105 | /* |
1106 | * rq_size is the size of the request plus driver payload, rounded |
1107 | * to the cacheline size |
1108 | */ |
1109 | rq_size = round_up(sizeof(struct request) + hctx->cmd_size, |
1110 | cache_line_size()); |
1111 | left = rq_size * hctx->queue_depth; |
1112 | |
1113 | for (i = 0; i < hctx->queue_depth;) { |
1114 | int this_order = max_order; |
1115 | struct page *page; |
1116 | int to_do; |
1117 | void *p; |
1118 | |
1119 | while (left < order_to_size(this_order - 1) && this_order) |
1120 | this_order--; |
1121 | |
1122 | do { |
1123 | page = alloc_pages_node(node, GFP_KERNEL, this_order); |
1124 | if (page) |
1125 | break; |
1126 | if (!this_order--) |
1127 | break; |
1128 | if (order_to_size(this_order) < rq_size) |
1129 | break; |
1130 | } while (1); |
1131 | |
1132 | if (!page) |
1133 | break; |
1134 | |
1135 | page->private = this_order; |
1136 | list_add_tail(&page->lru, &hctx->page_list); |
1137 | |
1138 | p = page_address(page); |
1139 | entries_per_page = order_to_size(this_order) / rq_size; |
1140 | to_do = min(entries_per_page, hctx->queue_depth - i); |
1141 | left -= to_do * rq_size; |
1142 | for (j = 0; j < to_do; j++) { |
1143 | hctx->rqs[i] = p; |
1144 | blk_mq_rq_init(hctx, hctx->rqs[i]); |
1145 | p += rq_size; |
1146 | i++; |
1147 | } |
1148 | } |
1149 | |
1150 | if (i < (reserved_tags + BLK_MQ_TAG_MIN)) |
1151 | goto err_rq_map; |
1152 | else if (i != hctx->queue_depth) { |
1153 | hctx->queue_depth = i; |
1154 | pr_warn("%s: queue depth set to %u because of low memory\n", |
1155 | __func__, i); |
1156 | } |
1157 | |
1158 | hctx->tags = blk_mq_init_tags(hctx->queue_depth, reserved_tags, node); |
1159 | if (!hctx->tags) { |
1160 | err_rq_map: |
1161 | blk_mq_free_rq_map(hctx); |
1162 | return -ENOMEM; |
1163 | } |
1164 | |
1165 | return 0; |
1166 | } |
1167 | |
1168 | static int blk_mq_init_hw_queues(struct request_queue *q, |
1169 | struct blk_mq_reg *reg, void *driver_data) |
1170 | { |
1171 | struct blk_mq_hw_ctx *hctx; |
1172 | unsigned int i, j; |
1173 | |
1174 | /* |
1175 | * Initialize hardware queues |
1176 | */ |
1177 | queue_for_each_hw_ctx(q, hctx, i) { |
1178 | unsigned int num_maps; |
1179 | int node; |
1180 | |
1181 | node = hctx->numa_node; |
1182 | if (node == NUMA_NO_NODE) |
1183 | node = hctx->numa_node = reg->numa_node; |
1184 | |
1185 | INIT_DELAYED_WORK(&hctx->delayed_work, blk_mq_work_fn); |
1186 | spin_lock_init(&hctx->lock); |
1187 | INIT_LIST_HEAD(&hctx->dispatch); |
1188 | hctx->queue = q; |
1189 | hctx->queue_num = i; |
1190 | hctx->flags = reg->flags; |
1191 | hctx->queue_depth = reg->queue_depth; |
1192 | hctx->cmd_size = reg->cmd_size; |
1193 | |
1194 | blk_mq_init_cpu_notifier(&hctx->cpu_notifier, |
1195 | blk_mq_hctx_notify, hctx); |
1196 | blk_mq_register_cpu_notifier(&hctx->cpu_notifier); |
1197 | |
1198 | if (blk_mq_init_rq_map(hctx, reg->reserved_tags, node)) |
1199 | break; |
1200 | |
1201 | /* |
1202 | * Allocate space for all possible cpus to avoid allocation in |
1203 | * runtime |
1204 | */ |
1205 | hctx->ctxs = kmalloc_node(nr_cpu_ids * sizeof(void *), |
1206 | GFP_KERNEL, node); |
1207 | if (!hctx->ctxs) |
1208 | break; |
1209 | |
1210 | num_maps = ALIGN(nr_cpu_ids, BITS_PER_LONG) / BITS_PER_LONG; |
1211 | hctx->ctx_map = kzalloc_node(num_maps * sizeof(unsigned long), |
1212 | GFP_KERNEL, node); |
1213 | if (!hctx->ctx_map) |
1214 | break; |
1215 | |
1216 | hctx->nr_ctx_map = num_maps; |
1217 | hctx->nr_ctx = 0; |
1218 | |
1219 | if (reg->ops->init_hctx && |
1220 | reg->ops->init_hctx(hctx, driver_data, i)) |
1221 | break; |
1222 | } |
1223 | |
1224 | if (i == q->nr_hw_queues) |
1225 | return 0; |
1226 | |
1227 | /* |
1228 | * Init failed |
1229 | */ |
1230 | queue_for_each_hw_ctx(q, hctx, j) { |
1231 | if (i == j) |
1232 | break; |
1233 | |
1234 | if (reg->ops->exit_hctx) |
1235 | reg->ops->exit_hctx(hctx, j); |
1236 | |
1237 | blk_mq_unregister_cpu_notifier(&hctx->cpu_notifier); |
1238 | blk_mq_free_rq_map(hctx); |
1239 | kfree(hctx->ctxs); |
1240 | } |
1241 | |
1242 | return 1; |
1243 | } |
1244 | |
1245 | static void blk_mq_init_cpu_queues(struct request_queue *q, |
1246 | unsigned int nr_hw_queues) |
1247 | { |
1248 | unsigned int i; |
1249 | |
1250 | for_each_possible_cpu(i) { |
1251 | struct blk_mq_ctx *__ctx = per_cpu_ptr(q->queue_ctx, i); |
1252 | struct blk_mq_hw_ctx *hctx; |
1253 | |
1254 | memset(__ctx, 0, sizeof(*__ctx)); |
1255 | __ctx->cpu = i; |
1256 | spin_lock_init(&__ctx->lock); |
1257 | INIT_LIST_HEAD(&__ctx->rq_list); |
1258 | __ctx->queue = q; |
1259 | |
1260 | /* If the cpu isn't online, the cpu is mapped to first hctx */ |
1261 | hctx = q->mq_ops->map_queue(q, i); |
1262 | hctx->nr_ctx++; |
1263 | |
1264 | if (!cpu_online(i)) |
1265 | continue; |
1266 | |
1267 | /* |
1268 | * Set local node, IFF we have more than one hw queue. If |
1269 | * not, we remain on the home node of the device |
1270 | */ |
1271 | if (nr_hw_queues > 1 && hctx->numa_node == NUMA_NO_NODE) |
1272 | hctx->numa_node = cpu_to_node(i); |
1273 | } |
1274 | } |
1275 | |
1276 | static void blk_mq_map_swqueue(struct request_queue *q) |
1277 | { |
1278 | unsigned int i; |
1279 | struct blk_mq_hw_ctx *hctx; |
1280 | struct blk_mq_ctx *ctx; |
1281 | |
1282 | queue_for_each_hw_ctx(q, hctx, i) { |
1283 | hctx->nr_ctx = 0; |
1284 | } |
1285 | |
1286 | /* |
1287 | * Map software to hardware queues |
1288 | */ |
1289 | queue_for_each_ctx(q, ctx, i) { |
1290 | /* If the cpu isn't online, the cpu is mapped to first hctx */ |
1291 | hctx = q->mq_ops->map_queue(q, i); |
1292 | ctx->index_hw = hctx->nr_ctx; |
1293 | hctx->ctxs[hctx->nr_ctx++] = ctx; |
1294 | } |
1295 | } |
1296 | |
1297 | struct request_queue *blk_mq_init_queue(struct blk_mq_reg *reg, |
1298 | void *driver_data) |
1299 | { |
1300 | struct blk_mq_hw_ctx **hctxs; |
1301 | struct blk_mq_ctx *ctx; |
1302 | struct request_queue *q; |
1303 | int i; |
1304 | |
1305 | if (!reg->nr_hw_queues || |
1306 | !reg->ops->queue_rq || !reg->ops->map_queue || |
1307 | !reg->ops->alloc_hctx || !reg->ops->free_hctx) |
1308 | return ERR_PTR(-EINVAL); |
1309 | |
1310 | if (!reg->queue_depth) |
1311 | reg->queue_depth = BLK_MQ_MAX_DEPTH; |
1312 | else if (reg->queue_depth > BLK_MQ_MAX_DEPTH) { |
1313 | pr_err("blk-mq: queuedepth too large (%u)\n", reg->queue_depth); |
1314 | reg->queue_depth = BLK_MQ_MAX_DEPTH; |
1315 | } |
1316 | |
1317 | if (reg->queue_depth < (reg->reserved_tags + BLK_MQ_TAG_MIN)) |
1318 | return ERR_PTR(-EINVAL); |
1319 | |
1320 | ctx = alloc_percpu(struct blk_mq_ctx); |
1321 | if (!ctx) |
1322 | return ERR_PTR(-ENOMEM); |
1323 | |
1324 | hctxs = kmalloc_node(reg->nr_hw_queues * sizeof(*hctxs), GFP_KERNEL, |
1325 | reg->numa_node); |
1326 | |
1327 | if (!hctxs) |
1328 | goto err_percpu; |
1329 | |
1330 | for (i = 0; i < reg->nr_hw_queues; i++) { |
1331 | hctxs[i] = reg->ops->alloc_hctx(reg, i); |
1332 | if (!hctxs[i]) |
1333 | goto err_hctxs; |
1334 | |
1335 | hctxs[i]->numa_node = NUMA_NO_NODE; |
1336 | hctxs[i]->queue_num = i; |
1337 | } |
1338 | |
1339 | q = blk_alloc_queue_node(GFP_KERNEL, reg->numa_node); |
1340 | if (!q) |
1341 | goto err_hctxs; |
1342 | |
1343 | q->mq_map = blk_mq_make_queue_map(reg); |
1344 | if (!q->mq_map) |
1345 | goto err_map; |
1346 | |
1347 | setup_timer(&q->timeout, blk_mq_rq_timer, (unsigned long) q); |
1348 | blk_queue_rq_timeout(q, 30000); |
1349 | |
1350 | q->nr_queues = nr_cpu_ids; |
1351 | q->nr_hw_queues = reg->nr_hw_queues; |
1352 | |
1353 | q->queue_ctx = ctx; |
1354 | q->queue_hw_ctx = hctxs; |
1355 | |
1356 | q->mq_ops = reg->ops; |
1357 | q->queue_flags |= QUEUE_FLAG_MQ_DEFAULT; |
1358 | |
1359 | q->sg_reserved_size = INT_MAX; |
1360 | |
1361 | blk_queue_make_request(q, blk_mq_make_request); |
1362 | blk_queue_rq_timed_out(q, reg->ops->timeout); |
1363 | if (reg->timeout) |
1364 | blk_queue_rq_timeout(q, reg->timeout); |
1365 | |
1366 | if (reg->ops->complete) |
1367 | blk_queue_softirq_done(q, reg->ops->complete); |
1368 | |
1369 | blk_mq_init_flush(q); |
1370 | blk_mq_init_cpu_queues(q, reg->nr_hw_queues); |
1371 | |
1372 | q->flush_rq = kzalloc(round_up(sizeof(struct request) + reg->cmd_size, |
1373 | cache_line_size()), GFP_KERNEL); |
1374 | if (!q->flush_rq) |
1375 | goto err_hw; |
1376 | |
1377 | if (blk_mq_init_hw_queues(q, reg, driver_data)) |
1378 | goto err_flush_rq; |
1379 | |
1380 | blk_mq_map_swqueue(q); |
1381 | |
1382 | mutex_lock(&all_q_mutex); |
1383 | list_add_tail(&q->all_q_node, &all_q_list); |
1384 | mutex_unlock(&all_q_mutex); |
1385 | |
1386 | return q; |
1387 | |
1388 | err_flush_rq: |
1389 | kfree(q->flush_rq); |
1390 | err_hw: |
1391 | kfree(q->mq_map); |
1392 | err_map: |
1393 | blk_cleanup_queue(q); |
1394 | err_hctxs: |
1395 | for (i = 0; i < reg->nr_hw_queues; i++) { |
1396 | if (!hctxs[i]) |
1397 | break; |
1398 | reg->ops->free_hctx(hctxs[i], i); |
1399 | } |
1400 | kfree(hctxs); |
1401 | err_percpu: |
1402 | free_percpu(ctx); |
1403 | return ERR_PTR(-ENOMEM); |
1404 | } |
1405 | EXPORT_SYMBOL(blk_mq_init_queue); |
1406 | |
1407 | void blk_mq_free_queue(struct request_queue *q) |
1408 | { |
1409 | struct blk_mq_hw_ctx *hctx; |
1410 | int i; |
1411 | |
1412 | queue_for_each_hw_ctx(q, hctx, i) { |
1413 | kfree(hctx->ctx_map); |
1414 | kfree(hctx->ctxs); |
1415 | blk_mq_free_rq_map(hctx); |
1416 | blk_mq_unregister_cpu_notifier(&hctx->cpu_notifier); |
1417 | if (q->mq_ops->exit_hctx) |
1418 | q->mq_ops->exit_hctx(hctx, i); |
1419 | q->mq_ops->free_hctx(hctx, i); |
1420 | } |
1421 | |
1422 | free_percpu(q->queue_ctx); |
1423 | kfree(q->queue_hw_ctx); |
1424 | kfree(q->mq_map); |
1425 | |
1426 | q->queue_ctx = NULL; |
1427 | q->queue_hw_ctx = NULL; |
1428 | q->mq_map = NULL; |
1429 | |
1430 | mutex_lock(&all_q_mutex); |
1431 | list_del_init(&q->all_q_node); |
1432 | mutex_unlock(&all_q_mutex); |
1433 | } |
1434 | |
1435 | /* Basically redo blk_mq_init_queue with queue frozen */ |
1436 | static void blk_mq_queue_reinit(struct request_queue *q) |
1437 | { |
1438 | blk_mq_freeze_queue(q); |
1439 | |
1440 | blk_mq_update_queue_map(q->mq_map, q->nr_hw_queues); |
1441 | |
1442 | /* |
1443 | * redo blk_mq_init_cpu_queues and blk_mq_init_hw_queues. FIXME: maybe |
1444 | * we should change hctx numa_node according to new topology (this |
1445 | * involves free and re-allocate memory, worthy doing?) |
1446 | */ |
1447 | |
1448 | blk_mq_map_swqueue(q); |
1449 | |
1450 | blk_mq_unfreeze_queue(q); |
1451 | } |
1452 | |
1453 | static int blk_mq_queue_reinit_notify(struct notifier_block *nb, |
1454 | unsigned long action, void *hcpu) |
1455 | { |
1456 | struct request_queue *q; |
1457 | |
1458 | /* |
1459 | * Before new mapping is established, hotadded cpu might already start |
1460 | * handling requests. This doesn't break anything as we map offline |
1461 | * CPUs to first hardware queue. We will re-init queue below to get |
1462 | * optimal settings. |
1463 | */ |
1464 | if (action != CPU_DEAD && action != CPU_DEAD_FROZEN && |
1465 | action != CPU_ONLINE && action != CPU_ONLINE_FROZEN) |
1466 | return NOTIFY_OK; |
1467 | |
1468 | mutex_lock(&all_q_mutex); |
1469 | list_for_each_entry(q, &all_q_list, all_q_node) |
1470 | blk_mq_queue_reinit(q); |
1471 | mutex_unlock(&all_q_mutex); |
1472 | return NOTIFY_OK; |
1473 | } |
1474 | |
1475 | void blk_mq_disable_hotplug(void) |
1476 | { |
1477 | mutex_lock(&all_q_mutex); |
1478 | } |
1479 | |
1480 | void blk_mq_enable_hotplug(void) |
1481 | { |
1482 | mutex_unlock(&all_q_mutex); |
1483 | } |
1484 | |
1485 | static int __init blk_mq_init(void) |
1486 | { |
1487 | blk_mq_cpu_init(); |
1488 | |
1489 | /* Must be called after percpu_counter_hotcpu_callback() */ |
1490 | hotcpu_notifier(blk_mq_queue_reinit_notify, -10); |
1491 | |
1492 | return 0; |
1493 | } |
1494 | subsys_initcall(blk_mq_init); |
1495 |
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