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320ae51f JA |
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 | ||
320ae51f JA |
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_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 | ||
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, | |
43a5e4e2 ML |
107 | !blk_queue_bypass(q) || blk_queue_dying(q), |
108 | *q->queue_lock); | |
320ae51f | 109 | /* inc usage with lock hold to avoid freeze_queue runs here */ |
43a5e4e2 | 110 | if (!ret && !blk_queue_dying(q)) |
320ae51f | 111 | __percpu_counter_add(&q->mq_usage_counter, 1, 1000000); |
43a5e4e2 ML |
112 | else if (blk_queue_dying(q)) |
113 | ret = -ENODEV; | |
320ae51f JA |
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 | ||
43a5e4e2 ML |
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 | ||
320ae51f JA |
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 | ||
43a5e4e2 ML |
153 | if (drain) |
154 | __blk_mq_drain_queue(q); | |
155 | } | |
320ae51f | 156 | |
43a5e4e2 ML |
157 | void blk_mq_drain_queue(struct request_queue *q) |
158 | { | |
159 | __blk_mq_drain_queue(q); | |
320ae51f JA |
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 | ||
94eddfbe JA |
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) | |
320ae51f | 185 | { |
94eddfbe JA |
186 | if (blk_queue_io_stat(q)) |
187 | rw_flags |= REQ_IO_STAT; | |
188 | ||
320ae51f JA |
189 | rq->mq_ctx = ctx; |
190 | rq->cmd_flags = rw_flags; | |
0fec08b4 ML |
191 | rq->start_time = jiffies; |
192 | set_start_time_ns(rq); | |
320ae51f JA |
193 | ctx->rq_dispatched[rw_is_sync(rw_flags)]++; |
194 | } | |
195 | ||
196 | static 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 | ||
202 | static 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) { | |
94eddfbe | 214 | blk_mq_rq_ctx_init(q, ctx, rq, rw); |
320ae51f | 215 | break; |
959a35f1 | 216 | } |
320ae51f JA |
217 | |
218 | blk_mq_put_ctx(ctx); | |
959a35f1 JM |
219 | if (!(gfp & __GFP_WAIT)) |
220 | break; | |
221 | ||
320ae51f JA |
222 | __blk_mq_run_hw_queue(hctx); |
223 | blk_mq_wait_for_tags(hctx->tags); | |
224 | } while (1); | |
225 | ||
226 | return rq; | |
227 | } | |
228 | ||
3228f48b CH |
229 | struct request *blk_mq_alloc_request(struct request_queue *q, int rw, |
230 | gfp_t gfp, bool reserved) | |
320ae51f JA |
231 | { |
232 | struct request *rq; | |
233 | ||
234 | if (blk_mq_queue_enter(q)) | |
235 | return NULL; | |
236 | ||
3228f48b | 237 | rq = blk_mq_alloc_request_pinned(q, rw, gfp, reserved); |
959a35f1 JM |
238 | if (rq) |
239 | blk_mq_put_ctx(rq->mq_ctx); | |
320ae51f JA |
240 | return rq; |
241 | } | |
242 | ||
243 | struct 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); | |
959a35f1 JM |
252 | if (rq) |
253 | blk_mq_put_ctx(rq->mq_ctx); | |
320ae51f JA |
254 | return rq; |
255 | } | |
256 | EXPORT_SYMBOL(blk_mq_alloc_reserved_request); | |
257 | ||
258 | /* | |
259 | * Re-init and set pdu, if we have it | |
260 | */ | |
261 | static 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 | ||
269 | static 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 | ||
281 | void 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 | ||
293 | static 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 | ||
308 | void 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; | |
4f024f37 | 319 | bytes += bio->bi_iter.bi_size; |
320ae51f JA |
320 | blk_mq_bio_endio(rq, bio, error); |
321 | bio = next; | |
322 | } | |
323 | ||
324 | blk_account_io_completion(rq, bytes); | |
325 | ||
0d11e6ac ML |
326 | blk_account_io_done(rq); |
327 | ||
320ae51f JA |
328 | if (rq->end_io) |
329 | rq->end_io(rq, error); | |
330 | else | |
331 | blk_mq_free_request(rq); | |
320ae51f JA |
332 | } |
333 | ||
334 | void __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 | ||
3d6efbf6 | 340 | static void blk_mq_end_io_remote(void *data) |
320ae51f | 341 | { |
3d6efbf6 | 342 | struct request *rq = data; |
320ae51f | 343 | |
3d6efbf6 | 344 | __blk_mq_end_io(rq, rq->errors); |
320ae51f | 345 | } |
320ae51f JA |
346 | |
347 | /* | |
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 | */ | |
352 | void 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(); | |
3d6efbf6 CH |
361 | 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 { | |
320ae51f | 368 | __blk_mq_end_io(rq, error); |
3d6efbf6 | 369 | } |
320ae51f JA |
370 | put_cpu(); |
371 | } | |
372 | EXPORT_SYMBOL(blk_mq_end_io); | |
373 | ||
374 | static 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 | ||
389 | static 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 | ||
397 | struct blk_mq_timeout_data { | |
398 | struct blk_mq_hw_ctx *hctx; | |
399 | unsigned long *next; | |
400 | unsigned int *next_set; | |
401 | }; | |
402 | ||
403 | static 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 | ||
431 | static 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 | ||
448 | static 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 | */ | |
467 | static 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 | ||
501 | void 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 | */ | |
512 | static 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 | ||
618 | void 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 | ||
632 | void 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 | } | |
646 | EXPORT_SYMBOL(blk_mq_run_queues); | |
647 | ||
648 | void 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 | } | |
653 | EXPORT_SYMBOL(blk_mq_stop_hw_queue); | |
654 | ||
280d45f6 CH |
655 | void 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 | } | |
663 | EXPORT_SYMBOL(blk_mq_stop_hw_queues); | |
664 | ||
320ae51f JA |
665 | void 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 | } | |
670 | EXPORT_SYMBOL(blk_mq_start_hw_queue); | |
671 | ||
672 | void 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 | } | |
685 | EXPORT_SYMBOL(blk_mq_start_stopped_hw_queues); | |
686 | ||
687 | static 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 | ||
695 | static 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 | ||
01b983c9 JA |
700 | trace_block_rq_insert(hctx->queue, rq); |
701 | ||
320ae51f JA |
702 | 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 | ||
711 | void 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 | } | |
740 | EXPORT_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 | */ | |
746 | void 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 | ||
772 | static 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 | ||
810 | static 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 | ||
820 | void 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 | ||
867 | static 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 | ||
873 | static 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)) | |
94eddfbe | 905 | blk_mq_rq_ctx_init(q, ctx, rq, rw); |
320ae51f JA |
906 | 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); | |
92f399c7 | 934 | if (list_empty(&plug->mq_list)) |
320ae51f JA |
935 | 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 | */ | |
964 | run_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 | */ | |
971 | struct 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 | } | |
975 | EXPORT_SYMBOL(blk_mq_map_queue); | |
976 | ||
977 | struct 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 | } | |
983 | EXPORT_SYMBOL(blk_mq_alloc_single_hw_queue); | |
984 | ||
985 | void blk_mq_free_single_hw_queue(struct blk_mq_hw_ctx *hctx, | |
986 | unsigned int hctx_index) | |
987 | { | |
988 | kfree(hctx); | |
989 | } | |
990 | EXPORT_SYMBOL(blk_mq_free_single_hw_queue); | |
991 | ||
992 | static 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 | ||
1034 | static 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 | ||
1048 | void 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 | } | |
1059 | EXPORT_SYMBOL(blk_mq_init_commands); | |
1060 | ||
1061 | static 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)) { | |
6753471c DH |
1066 | page = list_first_entry(&hctx->page_list, struct page, lru); |
1067 | list_del_init(&page->lru); | |
320ae51f JA |
1068 | __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 | ||
1077 | static 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 | ||
1087 | static 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; | |
6753471c | 1131 | list_add_tail(&page->lru, &hctx->page_list); |
320ae51f JA |
1132 | |
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) { | |
1155 | err_rq_map: | |
1156 | blk_mq_free_rq_map(hctx); | |
1157 | return -ENOMEM; | |
1158 | } | |
1159 | ||
1160 | return 0; | |
1161 | } | |
1162 | ||
1163 | static 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 | ||
1240 | static 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 | ||
1271 | static 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 | ||
1292 | struct 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 | ||
3228f48b CH |
1312 | /* |
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 | ||
320ae51f JA |
1321 | 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; | |
94eddfbe | 1361 | q->queue_flags |= QUEUE_FLAG_MQ_DEFAULT; |
320ae51f JA |
1362 | |
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; | |
1381 | err_hw: | |
1382 | kfree(q->mq_map); | |
1383 | err_map: | |
1384 | blk_cleanup_queue(q); | |
1385 | err_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); | |
1392 | err_percpu: | |
1393 | free_percpu(ctx); | |
1394 | return ERR_PTR(-ENOMEM); | |
1395 | } | |
1396 | EXPORT_SYMBOL(blk_mq_init_queue); | |
1397 | ||
1398 | void 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) { | |
320ae51f JA |
1404 | 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 | } | |
320ae51f JA |
1425 | |
1426 | /* Basically redo blk_mq_init_queue with queue frozen */ | |
f618ef7c | 1427 | static void blk_mq_queue_reinit(struct request_queue *q) |
320ae51f JA |
1428 | { |
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 | ||
f618ef7c PG |
1444 | static int blk_mq_queue_reinit_notify(struct notifier_block *nb, |
1445 | unsigned long action, void *hcpu) | |
320ae51f JA |
1446 | { |
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 | ||
1466 | static int __init blk_mq_init(void) | |
1467 | { | |
320ae51f JA |
1468 | 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 | } | |
1475 | subsys_initcall(blk_mq_init); |