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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->ctx_map.map_size; i++) | |
60 | if (hctx->ctx_map.map[i].word) | |
61 | return true; | |
62 | ||
63 | return false; | |
64 | } | |
65 | ||
66 | static inline struct blk_align_bitmap *get_bm(struct blk_mq_hw_ctx *hctx, | |
67 | struct blk_mq_ctx *ctx) | |
68 | { | |
69 | return &hctx->ctx_map.map[ctx->index_hw / hctx->ctx_map.bits_per_word]; | |
70 | } | |
71 | ||
72 | #define CTX_TO_BIT(hctx, ctx) \ | |
73 | ((ctx)->index_hw & ((hctx)->ctx_map.bits_per_word - 1)) | |
74 | ||
75 | /* | |
76 | * Mark this ctx as having pending work in this hardware queue | |
77 | */ | |
78 | static void blk_mq_hctx_mark_pending(struct blk_mq_hw_ctx *hctx, | |
79 | struct blk_mq_ctx *ctx) | |
80 | { | |
81 | struct blk_align_bitmap *bm = get_bm(hctx, ctx); | |
82 | ||
83 | if (!test_bit(CTX_TO_BIT(hctx, ctx), &bm->word)) | |
84 | set_bit(CTX_TO_BIT(hctx, ctx), &bm->word); | |
85 | } | |
86 | ||
87 | static void blk_mq_hctx_clear_pending(struct blk_mq_hw_ctx *hctx, | |
88 | struct blk_mq_ctx *ctx) | |
89 | { | |
90 | struct blk_align_bitmap *bm = get_bm(hctx, ctx); | |
91 | ||
92 | clear_bit(CTX_TO_BIT(hctx, ctx), &bm->word); | |
93 | } | |
94 | ||
95 | static int blk_mq_queue_enter(struct request_queue *q) | |
96 | { | |
97 | int ret; | |
98 | ||
99 | __percpu_counter_add(&q->mq_usage_counter, 1, 1000000); | |
100 | smp_wmb(); | |
101 | /* we have problems to freeze the queue if it's initializing */ | |
102 | if (!blk_queue_bypass(q) || !blk_queue_init_done(q)) | |
103 | return 0; | |
104 | ||
105 | __percpu_counter_add(&q->mq_usage_counter, -1, 1000000); | |
106 | ||
107 | spin_lock_irq(q->queue_lock); | |
108 | ret = wait_event_interruptible_lock_irq(q->mq_freeze_wq, | |
109 | !blk_queue_bypass(q) || blk_queue_dying(q), | |
110 | *q->queue_lock); | |
111 | /* inc usage with lock hold to avoid freeze_queue runs here */ | |
112 | if (!ret && !blk_queue_dying(q)) | |
113 | __percpu_counter_add(&q->mq_usage_counter, 1, 1000000); | |
114 | else if (blk_queue_dying(q)) | |
115 | ret = -ENODEV; | |
116 | spin_unlock_irq(q->queue_lock); | |
117 | ||
118 | return ret; | |
119 | } | |
120 | ||
121 | static void blk_mq_queue_exit(struct request_queue *q) | |
122 | { | |
123 | __percpu_counter_add(&q->mq_usage_counter, -1, 1000000); | |
124 | } | |
125 | ||
126 | static void __blk_mq_drain_queue(struct request_queue *q) | |
127 | { | |
128 | while (true) { | |
129 | s64 count; | |
130 | ||
131 | spin_lock_irq(q->queue_lock); | |
132 | count = percpu_counter_sum(&q->mq_usage_counter); | |
133 | spin_unlock_irq(q->queue_lock); | |
134 | ||
135 | if (count == 0) | |
136 | break; | |
137 | blk_mq_run_queues(q, false); | |
138 | msleep(10); | |
139 | } | |
140 | } | |
141 | ||
142 | /* | |
143 | * Guarantee no request is in use, so we can change any data structure of | |
144 | * the queue afterward. | |
145 | */ | |
146 | static void blk_mq_freeze_queue(struct request_queue *q) | |
147 | { | |
148 | bool drain; | |
149 | ||
150 | spin_lock_irq(q->queue_lock); | |
151 | drain = !q->bypass_depth++; | |
152 | queue_flag_set(QUEUE_FLAG_BYPASS, q); | |
153 | spin_unlock_irq(q->queue_lock); | |
154 | ||
155 | if (drain) | |
156 | __blk_mq_drain_queue(q); | |
157 | } | |
158 | ||
159 | void blk_mq_drain_queue(struct request_queue *q) | |
160 | { | |
161 | __blk_mq_drain_queue(q); | |
162 | } | |
163 | ||
164 | static void blk_mq_unfreeze_queue(struct request_queue *q) | |
165 | { | |
166 | bool wake = false; | |
167 | ||
168 | spin_lock_irq(q->queue_lock); | |
169 | if (!--q->bypass_depth) { | |
170 | queue_flag_clear(QUEUE_FLAG_BYPASS, q); | |
171 | wake = true; | |
172 | } | |
173 | WARN_ON_ONCE(q->bypass_depth < 0); | |
174 | spin_unlock_irq(q->queue_lock); | |
175 | if (wake) | |
176 | wake_up_all(&q->mq_freeze_wq); | |
177 | } | |
178 | ||
179 | bool blk_mq_can_queue(struct blk_mq_hw_ctx *hctx) | |
180 | { | |
181 | return blk_mq_has_free_tags(hctx->tags); | |
182 | } | |
183 | EXPORT_SYMBOL(blk_mq_can_queue); | |
184 | ||
185 | static void blk_mq_rq_ctx_init(struct request_queue *q, struct blk_mq_ctx *ctx, | |
186 | struct request *rq, unsigned int rw_flags) | |
187 | { | |
188 | if (blk_queue_io_stat(q)) | |
189 | rw_flags |= REQ_IO_STAT; | |
190 | ||
191 | INIT_LIST_HEAD(&rq->queuelist); | |
192 | /* csd/requeue_work/fifo_time is initialized before use */ | |
193 | rq->q = q; | |
194 | rq->mq_ctx = ctx; | |
195 | rq->cmd_flags |= rw_flags; | |
196 | rq->cmd_type = 0; | |
197 | /* do not touch atomic flags, it needs atomic ops against the timer */ | |
198 | rq->cpu = -1; | |
199 | rq->__data_len = 0; | |
200 | rq->__sector = (sector_t) -1; | |
201 | rq->bio = NULL; | |
202 | rq->biotail = NULL; | |
203 | INIT_HLIST_NODE(&rq->hash); | |
204 | RB_CLEAR_NODE(&rq->rb_node); | |
205 | memset(&rq->flush, 0, max(sizeof(rq->flush), sizeof(rq->elv))); | |
206 | rq->rq_disk = NULL; | |
207 | rq->part = NULL; | |
208 | rq->start_time = jiffies; | |
209 | #ifdef CONFIG_BLK_CGROUP | |
210 | rq->rl = NULL; | |
211 | set_start_time_ns(rq); | |
212 | rq->io_start_time_ns = 0; | |
213 | #endif | |
214 | rq->nr_phys_segments = 0; | |
215 | #if defined(CONFIG_BLK_DEV_INTEGRITY) | |
216 | rq->nr_integrity_segments = 0; | |
217 | #endif | |
218 | rq->ioprio = 0; | |
219 | rq->special = NULL; | |
220 | /* tag was already set */ | |
221 | rq->errors = 0; | |
222 | memset(rq->__cmd, 0, sizeof(rq->__cmd)); | |
223 | rq->cmd = rq->__cmd; | |
224 | rq->cmd_len = BLK_MAX_CDB; | |
225 | ||
226 | rq->extra_len = 0; | |
227 | rq->sense_len = 0; | |
228 | rq->resid_len = 0; | |
229 | rq->sense = NULL; | |
230 | ||
231 | rq->deadline = 0; | |
232 | INIT_LIST_HEAD(&rq->timeout_list); | |
233 | rq->timeout = 0; | |
234 | rq->retries = 0; | |
235 | rq->end_io = NULL; | |
236 | rq->end_io_data = NULL; | |
237 | rq->next_rq = NULL; | |
238 | ||
239 | ctx->rq_dispatched[rw_is_sync(rw_flags)]++; | |
240 | } | |
241 | ||
242 | static struct request * | |
243 | __blk_mq_alloc_request(struct request_queue *q, struct blk_mq_hw_ctx *hctx, | |
244 | struct blk_mq_ctx *ctx, int rw, gfp_t gfp, bool reserved) | |
245 | { | |
246 | struct request *rq; | |
247 | unsigned int tag; | |
248 | ||
249 | tag = blk_mq_get_tag(hctx, &ctx->last_tag, gfp, reserved); | |
250 | if (tag != BLK_MQ_TAG_FAIL) { | |
251 | rq = hctx->tags->rqs[tag]; | |
252 | ||
253 | rq->cmd_flags = 0; | |
254 | if (blk_mq_tag_busy(hctx)) { | |
255 | rq->cmd_flags = REQ_MQ_INFLIGHT; | |
256 | atomic_inc(&hctx->nr_active); | |
257 | } | |
258 | ||
259 | rq->tag = tag; | |
260 | blk_mq_rq_ctx_init(q, ctx, rq, rw); | |
261 | return rq; | |
262 | } | |
263 | ||
264 | return NULL; | |
265 | } | |
266 | ||
267 | struct request *blk_mq_alloc_request(struct request_queue *q, int rw, gfp_t gfp, | |
268 | bool reserved) | |
269 | { | |
270 | struct blk_mq_ctx *ctx; | |
271 | struct blk_mq_hw_ctx *hctx; | |
272 | struct request *rq; | |
273 | ||
274 | if (blk_mq_queue_enter(q)) | |
275 | return NULL; | |
276 | ||
277 | ctx = blk_mq_get_ctx(q); | |
278 | hctx = q->mq_ops->map_queue(q, ctx->cpu); | |
279 | ||
280 | rq = __blk_mq_alloc_request(q, hctx, ctx, rw, gfp & ~__GFP_WAIT, | |
281 | reserved); | |
282 | if (!rq && (gfp & __GFP_WAIT)) { | |
283 | __blk_mq_run_hw_queue(hctx); | |
284 | blk_mq_put_ctx(ctx); | |
285 | ||
286 | ctx = blk_mq_get_ctx(q); | |
287 | hctx = q->mq_ops->map_queue(q, ctx->cpu); | |
288 | rq = __blk_mq_alloc_request(q, hctx, ctx, rw, gfp, reserved); | |
289 | } | |
290 | blk_mq_put_ctx(ctx); | |
291 | return rq; | |
292 | } | |
293 | EXPORT_SYMBOL(blk_mq_alloc_request); | |
294 | ||
295 | static void __blk_mq_free_request(struct blk_mq_hw_ctx *hctx, | |
296 | struct blk_mq_ctx *ctx, struct request *rq) | |
297 | { | |
298 | const int tag = rq->tag; | |
299 | struct request_queue *q = rq->q; | |
300 | ||
301 | if (rq->cmd_flags & REQ_MQ_INFLIGHT) | |
302 | atomic_dec(&hctx->nr_active); | |
303 | ||
304 | clear_bit(REQ_ATOM_STARTED, &rq->atomic_flags); | |
305 | blk_mq_put_tag(hctx, tag, &ctx->last_tag); | |
306 | blk_mq_queue_exit(q); | |
307 | } | |
308 | ||
309 | void blk_mq_free_request(struct request *rq) | |
310 | { | |
311 | struct blk_mq_ctx *ctx = rq->mq_ctx; | |
312 | struct blk_mq_hw_ctx *hctx; | |
313 | struct request_queue *q = rq->q; | |
314 | ||
315 | ctx->rq_completed[rq_is_sync(rq)]++; | |
316 | ||
317 | hctx = q->mq_ops->map_queue(q, ctx->cpu); | |
318 | __blk_mq_free_request(hctx, ctx, rq); | |
319 | } | |
320 | ||
321 | /* | |
322 | * Clone all relevant state from a request that has been put on hold in | |
323 | * the flush state machine into the preallocated flush request that hangs | |
324 | * off the request queue. | |
325 | * | |
326 | * For a driver the flush request should be invisible, that's why we are | |
327 | * impersonating the original request here. | |
328 | */ | |
329 | void blk_mq_clone_flush_request(struct request *flush_rq, | |
330 | struct request *orig_rq) | |
331 | { | |
332 | struct blk_mq_hw_ctx *hctx = | |
333 | orig_rq->q->mq_ops->map_queue(orig_rq->q, orig_rq->mq_ctx->cpu); | |
334 | ||
335 | flush_rq->mq_ctx = orig_rq->mq_ctx; | |
336 | flush_rq->tag = orig_rq->tag; | |
337 | memcpy(blk_mq_rq_to_pdu(flush_rq), blk_mq_rq_to_pdu(orig_rq), | |
338 | hctx->cmd_size); | |
339 | } | |
340 | ||
341 | inline void __blk_mq_end_io(struct request *rq, int error) | |
342 | { | |
343 | blk_account_io_done(rq); | |
344 | ||
345 | if (rq->end_io) { | |
346 | rq->end_io(rq, error); | |
347 | } else { | |
348 | if (unlikely(blk_bidi_rq(rq))) | |
349 | blk_mq_free_request(rq->next_rq); | |
350 | blk_mq_free_request(rq); | |
351 | } | |
352 | } | |
353 | EXPORT_SYMBOL(__blk_mq_end_io); | |
354 | ||
355 | void blk_mq_end_io(struct request *rq, int error) | |
356 | { | |
357 | if (blk_update_request(rq, error, blk_rq_bytes(rq))) | |
358 | BUG(); | |
359 | __blk_mq_end_io(rq, error); | |
360 | } | |
361 | EXPORT_SYMBOL(blk_mq_end_io); | |
362 | ||
363 | static void __blk_mq_complete_request_remote(void *data) | |
364 | { | |
365 | struct request *rq = data; | |
366 | ||
367 | rq->q->softirq_done_fn(rq); | |
368 | } | |
369 | ||
370 | void __blk_mq_complete_request(struct request *rq) | |
371 | { | |
372 | struct blk_mq_ctx *ctx = rq->mq_ctx; | |
373 | bool shared = false; | |
374 | int cpu; | |
375 | ||
376 | if (!test_bit(QUEUE_FLAG_SAME_COMP, &rq->q->queue_flags)) { | |
377 | rq->q->softirq_done_fn(rq); | |
378 | return; | |
379 | } | |
380 | ||
381 | cpu = get_cpu(); | |
382 | if (!test_bit(QUEUE_FLAG_SAME_FORCE, &rq->q->queue_flags)) | |
383 | shared = cpus_share_cache(cpu, ctx->cpu); | |
384 | ||
385 | if (cpu != ctx->cpu && !shared && cpu_online(ctx->cpu)) { | |
386 | rq->csd.func = __blk_mq_complete_request_remote; | |
387 | rq->csd.info = rq; | |
388 | rq->csd.flags = 0; | |
389 | smp_call_function_single_async(ctx->cpu, &rq->csd); | |
390 | } else { | |
391 | rq->q->softirq_done_fn(rq); | |
392 | } | |
393 | put_cpu(); | |
394 | } | |
395 | ||
396 | /** | |
397 | * blk_mq_complete_request - end I/O on a request | |
398 | * @rq: the request being processed | |
399 | * | |
400 | * Description: | |
401 | * Ends all I/O on a request. It does not handle partial completions. | |
402 | * The actual completion happens out-of-order, through a IPI handler. | |
403 | **/ | |
404 | void blk_mq_complete_request(struct request *rq) | |
405 | { | |
406 | struct request_queue *q = rq->q; | |
407 | ||
408 | if (unlikely(blk_should_fake_timeout(q))) | |
409 | return; | |
410 | if (!blk_mark_rq_complete(rq)) { | |
411 | if (q->softirq_done_fn) | |
412 | __blk_mq_complete_request(rq); | |
413 | else | |
414 | blk_mq_end_io(rq, rq->errors); | |
415 | } | |
416 | } | |
417 | EXPORT_SYMBOL(blk_mq_complete_request); | |
418 | ||
419 | static void blk_mq_start_request(struct request *rq, bool last) | |
420 | { | |
421 | struct request_queue *q = rq->q; | |
422 | ||
423 | trace_block_rq_issue(q, rq); | |
424 | ||
425 | rq->resid_len = blk_rq_bytes(rq); | |
426 | if (unlikely(blk_bidi_rq(rq))) | |
427 | rq->next_rq->resid_len = blk_rq_bytes(rq->next_rq); | |
428 | ||
429 | /* | |
430 | * Just mark start time and set the started bit. Due to memory | |
431 | * ordering, we know we'll see the correct deadline as long as | |
432 | * REQ_ATOMIC_STARTED is seen. Use the default queue timeout, | |
433 | * unless one has been set in the request. | |
434 | */ | |
435 | if (!rq->timeout) | |
436 | rq->deadline = jiffies + q->rq_timeout; | |
437 | else | |
438 | rq->deadline = jiffies + rq->timeout; | |
439 | ||
440 | /* | |
441 | * Mark us as started and clear complete. Complete might have been | |
442 | * set if requeue raced with timeout, which then marked it as | |
443 | * complete. So be sure to clear complete again when we start | |
444 | * the request, otherwise we'll ignore the completion event. | |
445 | */ | |
446 | set_bit(REQ_ATOM_STARTED, &rq->atomic_flags); | |
447 | clear_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags); | |
448 | ||
449 | if (q->dma_drain_size && blk_rq_bytes(rq)) { | |
450 | /* | |
451 | * Make sure space for the drain appears. We know we can do | |
452 | * this because max_hw_segments has been adjusted to be one | |
453 | * fewer than the device can handle. | |
454 | */ | |
455 | rq->nr_phys_segments++; | |
456 | } | |
457 | ||
458 | /* | |
459 | * Flag the last request in the series so that drivers know when IO | |
460 | * should be kicked off, if they don't do it on a per-request basis. | |
461 | * | |
462 | * Note: the flag isn't the only condition drivers should do kick off. | |
463 | * If drive is busy, the last request might not have the bit set. | |
464 | */ | |
465 | if (last) | |
466 | rq->cmd_flags |= REQ_END; | |
467 | } | |
468 | ||
469 | static void __blk_mq_requeue_request(struct request *rq) | |
470 | { | |
471 | struct request_queue *q = rq->q; | |
472 | ||
473 | trace_block_rq_requeue(q, rq); | |
474 | clear_bit(REQ_ATOM_STARTED, &rq->atomic_flags); | |
475 | ||
476 | rq->cmd_flags &= ~REQ_END; | |
477 | ||
478 | if (q->dma_drain_size && blk_rq_bytes(rq)) | |
479 | rq->nr_phys_segments--; | |
480 | } | |
481 | ||
482 | void blk_mq_requeue_request(struct request *rq) | |
483 | { | |
484 | __blk_mq_requeue_request(rq); | |
485 | blk_clear_rq_complete(rq); | |
486 | ||
487 | BUG_ON(blk_queued_rq(rq)); | |
488 | blk_mq_add_to_requeue_list(rq, true); | |
489 | } | |
490 | EXPORT_SYMBOL(blk_mq_requeue_request); | |
491 | ||
492 | static void blk_mq_requeue_work(struct work_struct *work) | |
493 | { | |
494 | struct request_queue *q = | |
495 | container_of(work, struct request_queue, requeue_work); | |
496 | LIST_HEAD(rq_list); | |
497 | struct request *rq, *next; | |
498 | unsigned long flags; | |
499 | ||
500 | spin_lock_irqsave(&q->requeue_lock, flags); | |
501 | list_splice_init(&q->requeue_list, &rq_list); | |
502 | spin_unlock_irqrestore(&q->requeue_lock, flags); | |
503 | ||
504 | list_for_each_entry_safe(rq, next, &rq_list, queuelist) { | |
505 | if (!(rq->cmd_flags & REQ_SOFTBARRIER)) | |
506 | continue; | |
507 | ||
508 | rq->cmd_flags &= ~REQ_SOFTBARRIER; | |
509 | list_del_init(&rq->queuelist); | |
510 | blk_mq_insert_request(rq, true, false, false); | |
511 | } | |
512 | ||
513 | while (!list_empty(&rq_list)) { | |
514 | rq = list_entry(rq_list.next, struct request, queuelist); | |
515 | list_del_init(&rq->queuelist); | |
516 | blk_mq_insert_request(rq, false, false, false); | |
517 | } | |
518 | ||
519 | blk_mq_run_queues(q, false); | |
520 | } | |
521 | ||
522 | void blk_mq_add_to_requeue_list(struct request *rq, bool at_head) | |
523 | { | |
524 | struct request_queue *q = rq->q; | |
525 | unsigned long flags; | |
526 | ||
527 | /* | |
528 | * We abuse this flag that is otherwise used by the I/O scheduler to | |
529 | * request head insertation from the workqueue. | |
530 | */ | |
531 | BUG_ON(rq->cmd_flags & REQ_SOFTBARRIER); | |
532 | ||
533 | spin_lock_irqsave(&q->requeue_lock, flags); | |
534 | if (at_head) { | |
535 | rq->cmd_flags |= REQ_SOFTBARRIER; | |
536 | list_add(&rq->queuelist, &q->requeue_list); | |
537 | } else { | |
538 | list_add_tail(&rq->queuelist, &q->requeue_list); | |
539 | } | |
540 | spin_unlock_irqrestore(&q->requeue_lock, flags); | |
541 | } | |
542 | EXPORT_SYMBOL(blk_mq_add_to_requeue_list); | |
543 | ||
544 | void blk_mq_kick_requeue_list(struct request_queue *q) | |
545 | { | |
546 | kblockd_schedule_work(&q->requeue_work); | |
547 | } | |
548 | EXPORT_SYMBOL(blk_mq_kick_requeue_list); | |
549 | ||
550 | struct request *blk_mq_tag_to_rq(struct blk_mq_tags *tags, unsigned int tag) | |
551 | { | |
552 | return tags->rqs[tag]; | |
553 | } | |
554 | EXPORT_SYMBOL(blk_mq_tag_to_rq); | |
555 | ||
556 | struct blk_mq_timeout_data { | |
557 | struct blk_mq_hw_ctx *hctx; | |
558 | unsigned long *next; | |
559 | unsigned int *next_set; | |
560 | }; | |
561 | ||
562 | static void blk_mq_timeout_check(void *__data, unsigned long *free_tags) | |
563 | { | |
564 | struct blk_mq_timeout_data *data = __data; | |
565 | struct blk_mq_hw_ctx *hctx = data->hctx; | |
566 | unsigned int tag; | |
567 | ||
568 | /* It may not be in flight yet (this is where | |
569 | * the REQ_ATOMIC_STARTED flag comes in). The requests are | |
570 | * statically allocated, so we know it's always safe to access the | |
571 | * memory associated with a bit offset into ->rqs[]. | |
572 | */ | |
573 | tag = 0; | |
574 | do { | |
575 | struct request *rq; | |
576 | ||
577 | tag = find_next_zero_bit(free_tags, hctx->tags->nr_tags, tag); | |
578 | if (tag >= hctx->tags->nr_tags) | |
579 | break; | |
580 | ||
581 | rq = blk_mq_tag_to_rq(hctx->tags, tag++); | |
582 | if (rq->q != hctx->queue) | |
583 | continue; | |
584 | if (!test_bit(REQ_ATOM_STARTED, &rq->atomic_flags)) | |
585 | continue; | |
586 | ||
587 | blk_rq_check_expired(rq, data->next, data->next_set); | |
588 | } while (1); | |
589 | } | |
590 | ||
591 | static void blk_mq_hw_ctx_check_timeout(struct blk_mq_hw_ctx *hctx, | |
592 | unsigned long *next, | |
593 | unsigned int *next_set) | |
594 | { | |
595 | struct blk_mq_timeout_data data = { | |
596 | .hctx = hctx, | |
597 | .next = next, | |
598 | .next_set = next_set, | |
599 | }; | |
600 | ||
601 | /* | |
602 | * Ask the tagging code to iterate busy requests, so we can | |
603 | * check them for timeout. | |
604 | */ | |
605 | blk_mq_tag_busy_iter(hctx->tags, blk_mq_timeout_check, &data); | |
606 | } | |
607 | ||
608 | static enum blk_eh_timer_return blk_mq_rq_timed_out(struct request *rq) | |
609 | { | |
610 | struct request_queue *q = rq->q; | |
611 | ||
612 | /* | |
613 | * We know that complete is set at this point. If STARTED isn't set | |
614 | * anymore, then the request isn't active and the "timeout" should | |
615 | * just be ignored. This can happen due to the bitflag ordering. | |
616 | * Timeout first checks if STARTED is set, and if it is, assumes | |
617 | * the request is active. But if we race with completion, then | |
618 | * we both flags will get cleared. So check here again, and ignore | |
619 | * a timeout event with a request that isn't active. | |
620 | */ | |
621 | if (!test_bit(REQ_ATOM_STARTED, &rq->atomic_flags)) | |
622 | return BLK_EH_NOT_HANDLED; | |
623 | ||
624 | if (!q->mq_ops->timeout) | |
625 | return BLK_EH_RESET_TIMER; | |
626 | ||
627 | return q->mq_ops->timeout(rq); | |
628 | } | |
629 | ||
630 | static void blk_mq_rq_timer(unsigned long data) | |
631 | { | |
632 | struct request_queue *q = (struct request_queue *) data; | |
633 | struct blk_mq_hw_ctx *hctx; | |
634 | unsigned long next = 0; | |
635 | int i, next_set = 0; | |
636 | ||
637 | queue_for_each_hw_ctx(q, hctx, i) { | |
638 | /* | |
639 | * If not software queues are currently mapped to this | |
640 | * hardware queue, there's nothing to check | |
641 | */ | |
642 | if (!hctx->nr_ctx || !hctx->tags) | |
643 | continue; | |
644 | ||
645 | blk_mq_hw_ctx_check_timeout(hctx, &next, &next_set); | |
646 | } | |
647 | ||
648 | if (next_set) { | |
649 | next = blk_rq_timeout(round_jiffies_up(next)); | |
650 | mod_timer(&q->timeout, next); | |
651 | } else { | |
652 | queue_for_each_hw_ctx(q, hctx, i) | |
653 | blk_mq_tag_idle(hctx); | |
654 | } | |
655 | } | |
656 | ||
657 | /* | |
658 | * Reverse check our software queue for entries that we could potentially | |
659 | * merge with. Currently includes a hand-wavy stop count of 8, to not spend | |
660 | * too much time checking for merges. | |
661 | */ | |
662 | static bool blk_mq_attempt_merge(struct request_queue *q, | |
663 | struct blk_mq_ctx *ctx, struct bio *bio) | |
664 | { | |
665 | struct request *rq; | |
666 | int checked = 8; | |
667 | ||
668 | list_for_each_entry_reverse(rq, &ctx->rq_list, queuelist) { | |
669 | int el_ret; | |
670 | ||
671 | if (!checked--) | |
672 | break; | |
673 | ||
674 | if (!blk_rq_merge_ok(rq, bio)) | |
675 | continue; | |
676 | ||
677 | el_ret = blk_try_merge(rq, bio); | |
678 | if (el_ret == ELEVATOR_BACK_MERGE) { | |
679 | if (bio_attempt_back_merge(q, rq, bio)) { | |
680 | ctx->rq_merged++; | |
681 | return true; | |
682 | } | |
683 | break; | |
684 | } else if (el_ret == ELEVATOR_FRONT_MERGE) { | |
685 | if (bio_attempt_front_merge(q, rq, bio)) { | |
686 | ctx->rq_merged++; | |
687 | return true; | |
688 | } | |
689 | break; | |
690 | } | |
691 | } | |
692 | ||
693 | return false; | |
694 | } | |
695 | ||
696 | /* | |
697 | * Process software queues that have been marked busy, splicing them | |
698 | * to the for-dispatch | |
699 | */ | |
700 | static void flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, struct list_head *list) | |
701 | { | |
702 | struct blk_mq_ctx *ctx; | |
703 | int i; | |
704 | ||
705 | for (i = 0; i < hctx->ctx_map.map_size; i++) { | |
706 | struct blk_align_bitmap *bm = &hctx->ctx_map.map[i]; | |
707 | unsigned int off, bit; | |
708 | ||
709 | if (!bm->word) | |
710 | continue; | |
711 | ||
712 | bit = 0; | |
713 | off = i * hctx->ctx_map.bits_per_word; | |
714 | do { | |
715 | bit = find_next_bit(&bm->word, bm->depth, bit); | |
716 | if (bit >= bm->depth) | |
717 | break; | |
718 | ||
719 | ctx = hctx->ctxs[bit + off]; | |
720 | clear_bit(bit, &bm->word); | |
721 | spin_lock(&ctx->lock); | |
722 | list_splice_tail_init(&ctx->rq_list, list); | |
723 | spin_unlock(&ctx->lock); | |
724 | ||
725 | bit++; | |
726 | } while (1); | |
727 | } | |
728 | } | |
729 | ||
730 | /* | |
731 | * Run this hardware queue, pulling any software queues mapped to it in. | |
732 | * Note that this function currently has various problems around ordering | |
733 | * of IO. In particular, we'd like FIFO behaviour on handling existing | |
734 | * items on the hctx->dispatch list. Ignore that for now. | |
735 | */ | |
736 | static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx) | |
737 | { | |
738 | struct request_queue *q = hctx->queue; | |
739 | struct request *rq; | |
740 | LIST_HEAD(rq_list); | |
741 | int queued; | |
742 | ||
743 | WARN_ON(!cpumask_test_cpu(raw_smp_processor_id(), hctx->cpumask)); | |
744 | ||
745 | if (unlikely(test_bit(BLK_MQ_S_STOPPED, &hctx->state))) | |
746 | return; | |
747 | ||
748 | hctx->run++; | |
749 | ||
750 | /* | |
751 | * Touch any software queue that has pending entries. | |
752 | */ | |
753 | flush_busy_ctxs(hctx, &rq_list); | |
754 | ||
755 | /* | |
756 | * If we have previous entries on our dispatch list, grab them | |
757 | * and stuff them at the front for more fair dispatch. | |
758 | */ | |
759 | if (!list_empty_careful(&hctx->dispatch)) { | |
760 | spin_lock(&hctx->lock); | |
761 | if (!list_empty(&hctx->dispatch)) | |
762 | list_splice_init(&hctx->dispatch, &rq_list); | |
763 | spin_unlock(&hctx->lock); | |
764 | } | |
765 | ||
766 | /* | |
767 | * Now process all the entries, sending them to the driver. | |
768 | */ | |
769 | queued = 0; | |
770 | while (!list_empty(&rq_list)) { | |
771 | int ret; | |
772 | ||
773 | rq = list_first_entry(&rq_list, struct request, queuelist); | |
774 | list_del_init(&rq->queuelist); | |
775 | ||
776 | blk_mq_start_request(rq, list_empty(&rq_list)); | |
777 | ||
778 | ret = q->mq_ops->queue_rq(hctx, rq); | |
779 | switch (ret) { | |
780 | case BLK_MQ_RQ_QUEUE_OK: | |
781 | queued++; | |
782 | continue; | |
783 | case BLK_MQ_RQ_QUEUE_BUSY: | |
784 | list_add(&rq->queuelist, &rq_list); | |
785 | __blk_mq_requeue_request(rq); | |
786 | break; | |
787 | default: | |
788 | pr_err("blk-mq: bad return on queue: %d\n", ret); | |
789 | case BLK_MQ_RQ_QUEUE_ERROR: | |
790 | rq->errors = -EIO; | |
791 | blk_mq_end_io(rq, rq->errors); | |
792 | break; | |
793 | } | |
794 | ||
795 | if (ret == BLK_MQ_RQ_QUEUE_BUSY) | |
796 | break; | |
797 | } | |
798 | ||
799 | if (!queued) | |
800 | hctx->dispatched[0]++; | |
801 | else if (queued < (1 << (BLK_MQ_MAX_DISPATCH_ORDER - 1))) | |
802 | hctx->dispatched[ilog2(queued) + 1]++; | |
803 | ||
804 | /* | |
805 | * Any items that need requeuing? Stuff them into hctx->dispatch, | |
806 | * that is where we will continue on next queue run. | |
807 | */ | |
808 | if (!list_empty(&rq_list)) { | |
809 | spin_lock(&hctx->lock); | |
810 | list_splice(&rq_list, &hctx->dispatch); | |
811 | spin_unlock(&hctx->lock); | |
812 | } | |
813 | } | |
814 | ||
815 | /* | |
816 | * It'd be great if the workqueue API had a way to pass | |
817 | * in a mask and had some smarts for more clever placement. | |
818 | * For now we just round-robin here, switching for every | |
819 | * BLK_MQ_CPU_WORK_BATCH queued items. | |
820 | */ | |
821 | static int blk_mq_hctx_next_cpu(struct blk_mq_hw_ctx *hctx) | |
822 | { | |
823 | int cpu = hctx->next_cpu; | |
824 | ||
825 | if (--hctx->next_cpu_batch <= 0) { | |
826 | int next_cpu; | |
827 | ||
828 | next_cpu = cpumask_next(hctx->next_cpu, hctx->cpumask); | |
829 | if (next_cpu >= nr_cpu_ids) | |
830 | next_cpu = cpumask_first(hctx->cpumask); | |
831 | ||
832 | hctx->next_cpu = next_cpu; | |
833 | hctx->next_cpu_batch = BLK_MQ_CPU_WORK_BATCH; | |
834 | } | |
835 | ||
836 | return cpu; | |
837 | } | |
838 | ||
839 | void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async) | |
840 | { | |
841 | if (unlikely(test_bit(BLK_MQ_S_STOPPED, &hctx->state))) | |
842 | return; | |
843 | ||
844 | if (!async && cpumask_test_cpu(smp_processor_id(), hctx->cpumask)) | |
845 | __blk_mq_run_hw_queue(hctx); | |
846 | else if (hctx->queue->nr_hw_queues == 1) | |
847 | kblockd_schedule_delayed_work(&hctx->run_work, 0); | |
848 | else { | |
849 | unsigned int cpu; | |
850 | ||
851 | cpu = blk_mq_hctx_next_cpu(hctx); | |
852 | kblockd_schedule_delayed_work_on(cpu, &hctx->run_work, 0); | |
853 | } | |
854 | } | |
855 | ||
856 | void blk_mq_run_queues(struct request_queue *q, bool async) | |
857 | { | |
858 | struct blk_mq_hw_ctx *hctx; | |
859 | int i; | |
860 | ||
861 | queue_for_each_hw_ctx(q, hctx, i) { | |
862 | if ((!blk_mq_hctx_has_pending(hctx) && | |
863 | list_empty_careful(&hctx->dispatch)) || | |
864 | test_bit(BLK_MQ_S_STOPPED, &hctx->state)) | |
865 | continue; | |
866 | ||
867 | preempt_disable(); | |
868 | blk_mq_run_hw_queue(hctx, async); | |
869 | preempt_enable(); | |
870 | } | |
871 | } | |
872 | EXPORT_SYMBOL(blk_mq_run_queues); | |
873 | ||
874 | void blk_mq_stop_hw_queue(struct blk_mq_hw_ctx *hctx) | |
875 | { | |
876 | cancel_delayed_work(&hctx->run_work); | |
877 | cancel_delayed_work(&hctx->delay_work); | |
878 | set_bit(BLK_MQ_S_STOPPED, &hctx->state); | |
879 | } | |
880 | EXPORT_SYMBOL(blk_mq_stop_hw_queue); | |
881 | ||
882 | void blk_mq_stop_hw_queues(struct request_queue *q) | |
883 | { | |
884 | struct blk_mq_hw_ctx *hctx; | |
885 | int i; | |
886 | ||
887 | queue_for_each_hw_ctx(q, hctx, i) | |
888 | blk_mq_stop_hw_queue(hctx); | |
889 | } | |
890 | EXPORT_SYMBOL(blk_mq_stop_hw_queues); | |
891 | ||
892 | void blk_mq_start_hw_queue(struct blk_mq_hw_ctx *hctx) | |
893 | { | |
894 | clear_bit(BLK_MQ_S_STOPPED, &hctx->state); | |
895 | ||
896 | preempt_disable(); | |
897 | __blk_mq_run_hw_queue(hctx); | |
898 | preempt_enable(); | |
899 | } | |
900 | EXPORT_SYMBOL(blk_mq_start_hw_queue); | |
901 | ||
902 | void blk_mq_start_hw_queues(struct request_queue *q) | |
903 | { | |
904 | struct blk_mq_hw_ctx *hctx; | |
905 | int i; | |
906 | ||
907 | queue_for_each_hw_ctx(q, hctx, i) | |
908 | blk_mq_start_hw_queue(hctx); | |
909 | } | |
910 | EXPORT_SYMBOL(blk_mq_start_hw_queues); | |
911 | ||
912 | ||
913 | void blk_mq_start_stopped_hw_queues(struct request_queue *q, bool async) | |
914 | { | |
915 | struct blk_mq_hw_ctx *hctx; | |
916 | int i; | |
917 | ||
918 | queue_for_each_hw_ctx(q, hctx, i) { | |
919 | if (!test_bit(BLK_MQ_S_STOPPED, &hctx->state)) | |
920 | continue; | |
921 | ||
922 | clear_bit(BLK_MQ_S_STOPPED, &hctx->state); | |
923 | preempt_disable(); | |
924 | blk_mq_run_hw_queue(hctx, async); | |
925 | preempt_enable(); | |
926 | } | |
927 | } | |
928 | EXPORT_SYMBOL(blk_mq_start_stopped_hw_queues); | |
929 | ||
930 | static void blk_mq_run_work_fn(struct work_struct *work) | |
931 | { | |
932 | struct blk_mq_hw_ctx *hctx; | |
933 | ||
934 | hctx = container_of(work, struct blk_mq_hw_ctx, run_work.work); | |
935 | ||
936 | __blk_mq_run_hw_queue(hctx); | |
937 | } | |
938 | ||
939 | static void blk_mq_delay_work_fn(struct work_struct *work) | |
940 | { | |
941 | struct blk_mq_hw_ctx *hctx; | |
942 | ||
943 | hctx = container_of(work, struct blk_mq_hw_ctx, delay_work.work); | |
944 | ||
945 | if (test_and_clear_bit(BLK_MQ_S_STOPPED, &hctx->state)) | |
946 | __blk_mq_run_hw_queue(hctx); | |
947 | } | |
948 | ||
949 | void blk_mq_delay_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs) | |
950 | { | |
951 | unsigned long tmo = msecs_to_jiffies(msecs); | |
952 | ||
953 | if (hctx->queue->nr_hw_queues == 1) | |
954 | kblockd_schedule_delayed_work(&hctx->delay_work, tmo); | |
955 | else { | |
956 | unsigned int cpu; | |
957 | ||
958 | cpu = blk_mq_hctx_next_cpu(hctx); | |
959 | kblockd_schedule_delayed_work_on(cpu, &hctx->delay_work, tmo); | |
960 | } | |
961 | } | |
962 | EXPORT_SYMBOL(blk_mq_delay_queue); | |
963 | ||
964 | static void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, | |
965 | struct request *rq, bool at_head) | |
966 | { | |
967 | struct blk_mq_ctx *ctx = rq->mq_ctx; | |
968 | ||
969 | trace_block_rq_insert(hctx->queue, rq); | |
970 | ||
971 | if (at_head) | |
972 | list_add(&rq->queuelist, &ctx->rq_list); | |
973 | else | |
974 | list_add_tail(&rq->queuelist, &ctx->rq_list); | |
975 | ||
976 | blk_mq_hctx_mark_pending(hctx, ctx); | |
977 | ||
978 | /* | |
979 | * We do this early, to ensure we are on the right CPU. | |
980 | */ | |
981 | blk_add_timer(rq); | |
982 | } | |
983 | ||
984 | void blk_mq_insert_request(struct request *rq, bool at_head, bool run_queue, | |
985 | bool async) | |
986 | { | |
987 | struct request_queue *q = rq->q; | |
988 | struct blk_mq_hw_ctx *hctx; | |
989 | struct blk_mq_ctx *ctx = rq->mq_ctx, *current_ctx; | |
990 | ||
991 | current_ctx = blk_mq_get_ctx(q); | |
992 | if (!cpu_online(ctx->cpu)) | |
993 | rq->mq_ctx = ctx = current_ctx; | |
994 | ||
995 | hctx = q->mq_ops->map_queue(q, ctx->cpu); | |
996 | ||
997 | if (rq->cmd_flags & (REQ_FLUSH | REQ_FUA) && | |
998 | !(rq->cmd_flags & (REQ_FLUSH_SEQ))) { | |
999 | blk_insert_flush(rq); | |
1000 | } else { | |
1001 | spin_lock(&ctx->lock); | |
1002 | __blk_mq_insert_request(hctx, rq, at_head); | |
1003 | spin_unlock(&ctx->lock); | |
1004 | } | |
1005 | ||
1006 | if (run_queue) | |
1007 | blk_mq_run_hw_queue(hctx, async); | |
1008 | ||
1009 | blk_mq_put_ctx(current_ctx); | |
1010 | } | |
1011 | ||
1012 | static void blk_mq_insert_requests(struct request_queue *q, | |
1013 | struct blk_mq_ctx *ctx, | |
1014 | struct list_head *list, | |
1015 | int depth, | |
1016 | bool from_schedule) | |
1017 | ||
1018 | { | |
1019 | struct blk_mq_hw_ctx *hctx; | |
1020 | struct blk_mq_ctx *current_ctx; | |
1021 | ||
1022 | trace_block_unplug(q, depth, !from_schedule); | |
1023 | ||
1024 | current_ctx = blk_mq_get_ctx(q); | |
1025 | ||
1026 | if (!cpu_online(ctx->cpu)) | |
1027 | ctx = current_ctx; | |
1028 | hctx = q->mq_ops->map_queue(q, ctx->cpu); | |
1029 | ||
1030 | /* | |
1031 | * preemption doesn't flush plug list, so it's possible ctx->cpu is | |
1032 | * offline now | |
1033 | */ | |
1034 | spin_lock(&ctx->lock); | |
1035 | while (!list_empty(list)) { | |
1036 | struct request *rq; | |
1037 | ||
1038 | rq = list_first_entry(list, struct request, queuelist); | |
1039 | list_del_init(&rq->queuelist); | |
1040 | rq->mq_ctx = ctx; | |
1041 | __blk_mq_insert_request(hctx, rq, false); | |
1042 | } | |
1043 | spin_unlock(&ctx->lock); | |
1044 | ||
1045 | blk_mq_run_hw_queue(hctx, from_schedule); | |
1046 | blk_mq_put_ctx(current_ctx); | |
1047 | } | |
1048 | ||
1049 | static int plug_ctx_cmp(void *priv, struct list_head *a, struct list_head *b) | |
1050 | { | |
1051 | struct request *rqa = container_of(a, struct request, queuelist); | |
1052 | struct request *rqb = container_of(b, struct request, queuelist); | |
1053 | ||
1054 | return !(rqa->mq_ctx < rqb->mq_ctx || | |
1055 | (rqa->mq_ctx == rqb->mq_ctx && | |
1056 | blk_rq_pos(rqa) < blk_rq_pos(rqb))); | |
1057 | } | |
1058 | ||
1059 | void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule) | |
1060 | { | |
1061 | struct blk_mq_ctx *this_ctx; | |
1062 | struct request_queue *this_q; | |
1063 | struct request *rq; | |
1064 | LIST_HEAD(list); | |
1065 | LIST_HEAD(ctx_list); | |
1066 | unsigned int depth; | |
1067 | ||
1068 | list_splice_init(&plug->mq_list, &list); | |
1069 | ||
1070 | list_sort(NULL, &list, plug_ctx_cmp); | |
1071 | ||
1072 | this_q = NULL; | |
1073 | this_ctx = NULL; | |
1074 | depth = 0; | |
1075 | ||
1076 | while (!list_empty(&list)) { | |
1077 | rq = list_entry_rq(list.next); | |
1078 | list_del_init(&rq->queuelist); | |
1079 | BUG_ON(!rq->q); | |
1080 | if (rq->mq_ctx != this_ctx) { | |
1081 | if (this_ctx) { | |
1082 | blk_mq_insert_requests(this_q, this_ctx, | |
1083 | &ctx_list, depth, | |
1084 | from_schedule); | |
1085 | } | |
1086 | ||
1087 | this_ctx = rq->mq_ctx; | |
1088 | this_q = rq->q; | |
1089 | depth = 0; | |
1090 | } | |
1091 | ||
1092 | depth++; | |
1093 | list_add_tail(&rq->queuelist, &ctx_list); | |
1094 | } | |
1095 | ||
1096 | /* | |
1097 | * If 'this_ctx' is set, we know we have entries to complete | |
1098 | * on 'ctx_list'. Do those. | |
1099 | */ | |
1100 | if (this_ctx) { | |
1101 | blk_mq_insert_requests(this_q, this_ctx, &ctx_list, depth, | |
1102 | from_schedule); | |
1103 | } | |
1104 | } | |
1105 | ||
1106 | static void blk_mq_bio_to_request(struct request *rq, struct bio *bio) | |
1107 | { | |
1108 | init_request_from_bio(rq, bio); | |
1109 | blk_account_io_start(rq, 1); | |
1110 | } | |
1111 | ||
1112 | static inline bool blk_mq_merge_queue_io(struct blk_mq_hw_ctx *hctx, | |
1113 | struct blk_mq_ctx *ctx, | |
1114 | struct request *rq, struct bio *bio) | |
1115 | { | |
1116 | struct request_queue *q = hctx->queue; | |
1117 | ||
1118 | if (!(hctx->flags & BLK_MQ_F_SHOULD_MERGE)) { | |
1119 | blk_mq_bio_to_request(rq, bio); | |
1120 | spin_lock(&ctx->lock); | |
1121 | insert_rq: | |
1122 | __blk_mq_insert_request(hctx, rq, false); | |
1123 | spin_unlock(&ctx->lock); | |
1124 | return false; | |
1125 | } else { | |
1126 | spin_lock(&ctx->lock); | |
1127 | if (!blk_mq_attempt_merge(q, ctx, bio)) { | |
1128 | blk_mq_bio_to_request(rq, bio); | |
1129 | goto insert_rq; | |
1130 | } | |
1131 | ||
1132 | spin_unlock(&ctx->lock); | |
1133 | __blk_mq_free_request(hctx, ctx, rq); | |
1134 | return true; | |
1135 | } | |
1136 | } | |
1137 | ||
1138 | struct blk_map_ctx { | |
1139 | struct blk_mq_hw_ctx *hctx; | |
1140 | struct blk_mq_ctx *ctx; | |
1141 | }; | |
1142 | ||
1143 | static struct request *blk_mq_map_request(struct request_queue *q, | |
1144 | struct bio *bio, | |
1145 | struct blk_map_ctx *data) | |
1146 | { | |
1147 | struct blk_mq_hw_ctx *hctx; | |
1148 | struct blk_mq_ctx *ctx; | |
1149 | struct request *rq; | |
1150 | int rw = bio_data_dir(bio); | |
1151 | ||
1152 | if (unlikely(blk_mq_queue_enter(q))) { | |
1153 | bio_endio(bio, -EIO); | |
1154 | return NULL; | |
1155 | } | |
1156 | ||
1157 | ctx = blk_mq_get_ctx(q); | |
1158 | hctx = q->mq_ops->map_queue(q, ctx->cpu); | |
1159 | ||
1160 | if (rw_is_sync(bio->bi_rw)) | |
1161 | rw |= REQ_SYNC; | |
1162 | ||
1163 | trace_block_getrq(q, bio, rw); | |
1164 | rq = __blk_mq_alloc_request(q, hctx, ctx, rw, GFP_ATOMIC, false); | |
1165 | if (unlikely(!rq)) { | |
1166 | __blk_mq_run_hw_queue(hctx); | |
1167 | blk_mq_put_ctx(ctx); | |
1168 | trace_block_sleeprq(q, bio, rw); | |
1169 | ||
1170 | ctx = blk_mq_get_ctx(q); | |
1171 | hctx = q->mq_ops->map_queue(q, ctx->cpu); | |
1172 | rq = __blk_mq_alloc_request(q, hctx, ctx, rw, | |
1173 | __GFP_WAIT|GFP_ATOMIC, false); | |
1174 | } | |
1175 | ||
1176 | hctx->queued++; | |
1177 | data->hctx = hctx; | |
1178 | data->ctx = ctx; | |
1179 | return rq; | |
1180 | } | |
1181 | ||
1182 | /* | |
1183 | * Multiple hardware queue variant. This will not use per-process plugs, | |
1184 | * but will attempt to bypass the hctx queueing if we can go straight to | |
1185 | * hardware for SYNC IO. | |
1186 | */ | |
1187 | static void blk_mq_make_request(struct request_queue *q, struct bio *bio) | |
1188 | { | |
1189 | const int is_sync = rw_is_sync(bio->bi_rw); | |
1190 | const int is_flush_fua = bio->bi_rw & (REQ_FLUSH | REQ_FUA); | |
1191 | struct blk_map_ctx data; | |
1192 | struct request *rq; | |
1193 | ||
1194 | blk_queue_bounce(q, &bio); | |
1195 | ||
1196 | if (bio_integrity_enabled(bio) && bio_integrity_prep(bio)) { | |
1197 | bio_endio(bio, -EIO); | |
1198 | return; | |
1199 | } | |
1200 | ||
1201 | rq = blk_mq_map_request(q, bio, &data); | |
1202 | if (unlikely(!rq)) | |
1203 | return; | |
1204 | ||
1205 | if (unlikely(is_flush_fua)) { | |
1206 | blk_mq_bio_to_request(rq, bio); | |
1207 | blk_insert_flush(rq); | |
1208 | goto run_queue; | |
1209 | } | |
1210 | ||
1211 | if (is_sync) { | |
1212 | int ret; | |
1213 | ||
1214 | blk_mq_bio_to_request(rq, bio); | |
1215 | blk_mq_start_request(rq, true); | |
1216 | ||
1217 | /* | |
1218 | * For OK queue, we are done. For error, kill it. Any other | |
1219 | * error (busy), just add it to our list as we previously | |
1220 | * would have done | |
1221 | */ | |
1222 | ret = q->mq_ops->queue_rq(data.hctx, rq); | |
1223 | if (ret == BLK_MQ_RQ_QUEUE_OK) | |
1224 | goto done; | |
1225 | else { | |
1226 | __blk_mq_requeue_request(rq); | |
1227 | ||
1228 | if (ret == BLK_MQ_RQ_QUEUE_ERROR) { | |
1229 | rq->errors = -EIO; | |
1230 | blk_mq_end_io(rq, rq->errors); | |
1231 | goto done; | |
1232 | } | |
1233 | } | |
1234 | } | |
1235 | ||
1236 | if (!blk_mq_merge_queue_io(data.hctx, data.ctx, rq, bio)) { | |
1237 | /* | |
1238 | * For a SYNC request, send it to the hardware immediately. For | |
1239 | * an ASYNC request, just ensure that we run it later on. The | |
1240 | * latter allows for merging opportunities and more efficient | |
1241 | * dispatching. | |
1242 | */ | |
1243 | run_queue: | |
1244 | blk_mq_run_hw_queue(data.hctx, !is_sync || is_flush_fua); | |
1245 | } | |
1246 | done: | |
1247 | blk_mq_put_ctx(data.ctx); | |
1248 | } | |
1249 | ||
1250 | /* | |
1251 | * Single hardware queue variant. This will attempt to use any per-process | |
1252 | * plug for merging and IO deferral. | |
1253 | */ | |
1254 | static void blk_sq_make_request(struct request_queue *q, struct bio *bio) | |
1255 | { | |
1256 | const int is_sync = rw_is_sync(bio->bi_rw); | |
1257 | const int is_flush_fua = bio->bi_rw & (REQ_FLUSH | REQ_FUA); | |
1258 | unsigned int use_plug, request_count = 0; | |
1259 | struct blk_map_ctx data; | |
1260 | struct request *rq; | |
1261 | ||
1262 | /* | |
1263 | * If we have multiple hardware queues, just go directly to | |
1264 | * one of those for sync IO. | |
1265 | */ | |
1266 | use_plug = !is_flush_fua && !is_sync; | |
1267 | ||
1268 | blk_queue_bounce(q, &bio); | |
1269 | ||
1270 | if (bio_integrity_enabled(bio) && bio_integrity_prep(bio)) { | |
1271 | bio_endio(bio, -EIO); | |
1272 | return; | |
1273 | } | |
1274 | ||
1275 | if (use_plug && !blk_queue_nomerges(q) && | |
1276 | blk_attempt_plug_merge(q, bio, &request_count)) | |
1277 | return; | |
1278 | ||
1279 | rq = blk_mq_map_request(q, bio, &data); | |
1280 | ||
1281 | if (unlikely(is_flush_fua)) { | |
1282 | blk_mq_bio_to_request(rq, bio); | |
1283 | blk_insert_flush(rq); | |
1284 | goto run_queue; | |
1285 | } | |
1286 | ||
1287 | /* | |
1288 | * A task plug currently exists. Since this is completely lockless, | |
1289 | * utilize that to temporarily store requests until the task is | |
1290 | * either done or scheduled away. | |
1291 | */ | |
1292 | if (use_plug) { | |
1293 | struct blk_plug *plug = current->plug; | |
1294 | ||
1295 | if (plug) { | |
1296 | blk_mq_bio_to_request(rq, bio); | |
1297 | if (list_empty(&plug->mq_list)) | |
1298 | trace_block_plug(q); | |
1299 | else if (request_count >= BLK_MAX_REQUEST_COUNT) { | |
1300 | blk_flush_plug_list(plug, false); | |
1301 | trace_block_plug(q); | |
1302 | } | |
1303 | list_add_tail(&rq->queuelist, &plug->mq_list); | |
1304 | blk_mq_put_ctx(data.ctx); | |
1305 | return; | |
1306 | } | |
1307 | } | |
1308 | ||
1309 | if (!blk_mq_merge_queue_io(data.hctx, data.ctx, rq, bio)) { | |
1310 | /* | |
1311 | * For a SYNC request, send it to the hardware immediately. For | |
1312 | * an ASYNC request, just ensure that we run it later on. The | |
1313 | * latter allows for merging opportunities and more efficient | |
1314 | * dispatching. | |
1315 | */ | |
1316 | run_queue: | |
1317 | blk_mq_run_hw_queue(data.hctx, !is_sync || is_flush_fua); | |
1318 | } | |
1319 | ||
1320 | blk_mq_put_ctx(data.ctx); | |
1321 | } | |
1322 | ||
1323 | /* | |
1324 | * Default mapping to a software queue, since we use one per CPU. | |
1325 | */ | |
1326 | struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q, const int cpu) | |
1327 | { | |
1328 | return q->queue_hw_ctx[q->mq_map[cpu]]; | |
1329 | } | |
1330 | EXPORT_SYMBOL(blk_mq_map_queue); | |
1331 | ||
1332 | struct blk_mq_hw_ctx *blk_mq_alloc_single_hw_queue(struct blk_mq_tag_set *set, | |
1333 | unsigned int hctx_index, | |
1334 | int node) | |
1335 | { | |
1336 | return kzalloc_node(sizeof(struct blk_mq_hw_ctx), GFP_KERNEL, node); | |
1337 | } | |
1338 | EXPORT_SYMBOL(blk_mq_alloc_single_hw_queue); | |
1339 | ||
1340 | void blk_mq_free_single_hw_queue(struct blk_mq_hw_ctx *hctx, | |
1341 | unsigned int hctx_index) | |
1342 | { | |
1343 | kfree(hctx); | |
1344 | } | |
1345 | EXPORT_SYMBOL(blk_mq_free_single_hw_queue); | |
1346 | ||
1347 | static void blk_mq_free_rq_map(struct blk_mq_tag_set *set, | |
1348 | struct blk_mq_tags *tags, unsigned int hctx_idx) | |
1349 | { | |
1350 | struct page *page; | |
1351 | ||
1352 | if (tags->rqs && set->ops->exit_request) { | |
1353 | int i; | |
1354 | ||
1355 | for (i = 0; i < tags->nr_tags; i++) { | |
1356 | if (!tags->rqs[i]) | |
1357 | continue; | |
1358 | set->ops->exit_request(set->driver_data, tags->rqs[i], | |
1359 | hctx_idx, i); | |
1360 | } | |
1361 | } | |
1362 | ||
1363 | while (!list_empty(&tags->page_list)) { | |
1364 | page = list_first_entry(&tags->page_list, struct page, lru); | |
1365 | list_del_init(&page->lru); | |
1366 | __free_pages(page, page->private); | |
1367 | } | |
1368 | ||
1369 | kfree(tags->rqs); | |
1370 | ||
1371 | blk_mq_free_tags(tags); | |
1372 | } | |
1373 | ||
1374 | static size_t order_to_size(unsigned int order) | |
1375 | { | |
1376 | return (size_t)PAGE_SIZE << order; | |
1377 | } | |
1378 | ||
1379 | static struct blk_mq_tags *blk_mq_init_rq_map(struct blk_mq_tag_set *set, | |
1380 | unsigned int hctx_idx) | |
1381 | { | |
1382 | struct blk_mq_tags *tags; | |
1383 | unsigned int i, j, entries_per_page, max_order = 4; | |
1384 | size_t rq_size, left; | |
1385 | ||
1386 | tags = blk_mq_init_tags(set->queue_depth, set->reserved_tags, | |
1387 | set->numa_node); | |
1388 | if (!tags) | |
1389 | return NULL; | |
1390 | ||
1391 | INIT_LIST_HEAD(&tags->page_list); | |
1392 | ||
1393 | tags->rqs = kmalloc_node(set->queue_depth * sizeof(struct request *), | |
1394 | GFP_KERNEL, set->numa_node); | |
1395 | if (!tags->rqs) { | |
1396 | blk_mq_free_tags(tags); | |
1397 | return NULL; | |
1398 | } | |
1399 | ||
1400 | /* | |
1401 | * rq_size is the size of the request plus driver payload, rounded | |
1402 | * to the cacheline size | |
1403 | */ | |
1404 | rq_size = round_up(sizeof(struct request) + set->cmd_size, | |
1405 | cache_line_size()); | |
1406 | left = rq_size * set->queue_depth; | |
1407 | ||
1408 | for (i = 0; i < set->queue_depth; ) { | |
1409 | int this_order = max_order; | |
1410 | struct page *page; | |
1411 | int to_do; | |
1412 | void *p; | |
1413 | ||
1414 | while (left < order_to_size(this_order - 1) && this_order) | |
1415 | this_order--; | |
1416 | ||
1417 | do { | |
1418 | page = alloc_pages_node(set->numa_node, GFP_KERNEL, | |
1419 | this_order); | |
1420 | if (page) | |
1421 | break; | |
1422 | if (!this_order--) | |
1423 | break; | |
1424 | if (order_to_size(this_order) < rq_size) | |
1425 | break; | |
1426 | } while (1); | |
1427 | ||
1428 | if (!page) | |
1429 | goto fail; | |
1430 | ||
1431 | page->private = this_order; | |
1432 | list_add_tail(&page->lru, &tags->page_list); | |
1433 | ||
1434 | p = page_address(page); | |
1435 | entries_per_page = order_to_size(this_order) / rq_size; | |
1436 | to_do = min(entries_per_page, set->queue_depth - i); | |
1437 | left -= to_do * rq_size; | |
1438 | for (j = 0; j < to_do; j++) { | |
1439 | tags->rqs[i] = p; | |
1440 | if (set->ops->init_request) { | |
1441 | if (set->ops->init_request(set->driver_data, | |
1442 | tags->rqs[i], hctx_idx, i, | |
1443 | set->numa_node)) | |
1444 | goto fail; | |
1445 | } | |
1446 | ||
1447 | p += rq_size; | |
1448 | i++; | |
1449 | } | |
1450 | } | |
1451 | ||
1452 | return tags; | |
1453 | ||
1454 | fail: | |
1455 | pr_warn("%s: failed to allocate requests\n", __func__); | |
1456 | blk_mq_free_rq_map(set, tags, hctx_idx); | |
1457 | return NULL; | |
1458 | } | |
1459 | ||
1460 | static void blk_mq_free_bitmap(struct blk_mq_ctxmap *bitmap) | |
1461 | { | |
1462 | kfree(bitmap->map); | |
1463 | } | |
1464 | ||
1465 | static int blk_mq_alloc_bitmap(struct blk_mq_ctxmap *bitmap, int node) | |
1466 | { | |
1467 | unsigned int bpw = 8, total, num_maps, i; | |
1468 | ||
1469 | bitmap->bits_per_word = bpw; | |
1470 | ||
1471 | num_maps = ALIGN(nr_cpu_ids, bpw) / bpw; | |
1472 | bitmap->map = kzalloc_node(num_maps * sizeof(struct blk_align_bitmap), | |
1473 | GFP_KERNEL, node); | |
1474 | if (!bitmap->map) | |
1475 | return -ENOMEM; | |
1476 | ||
1477 | bitmap->map_size = num_maps; | |
1478 | ||
1479 | total = nr_cpu_ids; | |
1480 | for (i = 0; i < num_maps; i++) { | |
1481 | bitmap->map[i].depth = min(total, bitmap->bits_per_word); | |
1482 | total -= bitmap->map[i].depth; | |
1483 | } | |
1484 | ||
1485 | return 0; | |
1486 | } | |
1487 | ||
1488 | static int blk_mq_hctx_cpu_offline(struct blk_mq_hw_ctx *hctx, int cpu) | |
1489 | { | |
1490 | struct request_queue *q = hctx->queue; | |
1491 | struct blk_mq_ctx *ctx; | |
1492 | LIST_HEAD(tmp); | |
1493 | ||
1494 | /* | |
1495 | * Move ctx entries to new CPU, if this one is going away. | |
1496 | */ | |
1497 | ctx = __blk_mq_get_ctx(q, cpu); | |
1498 | ||
1499 | spin_lock(&ctx->lock); | |
1500 | if (!list_empty(&ctx->rq_list)) { | |
1501 | list_splice_init(&ctx->rq_list, &tmp); | |
1502 | blk_mq_hctx_clear_pending(hctx, ctx); | |
1503 | } | |
1504 | spin_unlock(&ctx->lock); | |
1505 | ||
1506 | if (list_empty(&tmp)) | |
1507 | return NOTIFY_OK; | |
1508 | ||
1509 | ctx = blk_mq_get_ctx(q); | |
1510 | spin_lock(&ctx->lock); | |
1511 | ||
1512 | while (!list_empty(&tmp)) { | |
1513 | struct request *rq; | |
1514 | ||
1515 | rq = list_first_entry(&tmp, struct request, queuelist); | |
1516 | rq->mq_ctx = ctx; | |
1517 | list_move_tail(&rq->queuelist, &ctx->rq_list); | |
1518 | } | |
1519 | ||
1520 | hctx = q->mq_ops->map_queue(q, ctx->cpu); | |
1521 | blk_mq_hctx_mark_pending(hctx, ctx); | |
1522 | ||
1523 | spin_unlock(&ctx->lock); | |
1524 | ||
1525 | blk_mq_run_hw_queue(hctx, true); | |
1526 | blk_mq_put_ctx(ctx); | |
1527 | return NOTIFY_OK; | |
1528 | } | |
1529 | ||
1530 | static int blk_mq_hctx_cpu_online(struct blk_mq_hw_ctx *hctx, int cpu) | |
1531 | { | |
1532 | struct request_queue *q = hctx->queue; | |
1533 | struct blk_mq_tag_set *set = q->tag_set; | |
1534 | ||
1535 | if (set->tags[hctx->queue_num]) | |
1536 | return NOTIFY_OK; | |
1537 | ||
1538 | set->tags[hctx->queue_num] = blk_mq_init_rq_map(set, hctx->queue_num); | |
1539 | if (!set->tags[hctx->queue_num]) | |
1540 | return NOTIFY_STOP; | |
1541 | ||
1542 | hctx->tags = set->tags[hctx->queue_num]; | |
1543 | return NOTIFY_OK; | |
1544 | } | |
1545 | ||
1546 | static int blk_mq_hctx_notify(void *data, unsigned long action, | |
1547 | unsigned int cpu) | |
1548 | { | |
1549 | struct blk_mq_hw_ctx *hctx = data; | |
1550 | ||
1551 | if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) | |
1552 | return blk_mq_hctx_cpu_offline(hctx, cpu); | |
1553 | else if (action == CPU_ONLINE || action == CPU_ONLINE_FROZEN) | |
1554 | return blk_mq_hctx_cpu_online(hctx, cpu); | |
1555 | ||
1556 | return NOTIFY_OK; | |
1557 | } | |
1558 | ||
1559 | static void blk_mq_exit_hw_queues(struct request_queue *q, | |
1560 | struct blk_mq_tag_set *set, int nr_queue) | |
1561 | { | |
1562 | struct blk_mq_hw_ctx *hctx; | |
1563 | unsigned int i; | |
1564 | ||
1565 | queue_for_each_hw_ctx(q, hctx, i) { | |
1566 | if (i == nr_queue) | |
1567 | break; | |
1568 | ||
1569 | if (set->ops->exit_hctx) | |
1570 | set->ops->exit_hctx(hctx, i); | |
1571 | ||
1572 | blk_mq_unregister_cpu_notifier(&hctx->cpu_notifier); | |
1573 | kfree(hctx->ctxs); | |
1574 | blk_mq_free_bitmap(&hctx->ctx_map); | |
1575 | } | |
1576 | ||
1577 | } | |
1578 | ||
1579 | static void blk_mq_free_hw_queues(struct request_queue *q, | |
1580 | struct blk_mq_tag_set *set) | |
1581 | { | |
1582 | struct blk_mq_hw_ctx *hctx; | |
1583 | unsigned int i; | |
1584 | ||
1585 | queue_for_each_hw_ctx(q, hctx, i) { | |
1586 | free_cpumask_var(hctx->cpumask); | |
1587 | set->ops->free_hctx(hctx, i); | |
1588 | } | |
1589 | } | |
1590 | ||
1591 | static int blk_mq_init_hw_queues(struct request_queue *q, | |
1592 | struct blk_mq_tag_set *set) | |
1593 | { | |
1594 | struct blk_mq_hw_ctx *hctx; | |
1595 | unsigned int i; | |
1596 | ||
1597 | /* | |
1598 | * Initialize hardware queues | |
1599 | */ | |
1600 | queue_for_each_hw_ctx(q, hctx, i) { | |
1601 | int node; | |
1602 | ||
1603 | node = hctx->numa_node; | |
1604 | if (node == NUMA_NO_NODE) | |
1605 | node = hctx->numa_node = set->numa_node; | |
1606 | ||
1607 | INIT_DELAYED_WORK(&hctx->run_work, blk_mq_run_work_fn); | |
1608 | INIT_DELAYED_WORK(&hctx->delay_work, blk_mq_delay_work_fn); | |
1609 | spin_lock_init(&hctx->lock); | |
1610 | INIT_LIST_HEAD(&hctx->dispatch); | |
1611 | hctx->queue = q; | |
1612 | hctx->queue_num = i; | |
1613 | hctx->flags = set->flags; | |
1614 | hctx->cmd_size = set->cmd_size; | |
1615 | ||
1616 | blk_mq_init_cpu_notifier(&hctx->cpu_notifier, | |
1617 | blk_mq_hctx_notify, hctx); | |
1618 | blk_mq_register_cpu_notifier(&hctx->cpu_notifier); | |
1619 | ||
1620 | hctx->tags = set->tags[i]; | |
1621 | ||
1622 | /* | |
1623 | * Allocate space for all possible cpus to avoid allocation in | |
1624 | * runtime | |
1625 | */ | |
1626 | hctx->ctxs = kmalloc_node(nr_cpu_ids * sizeof(void *), | |
1627 | GFP_KERNEL, node); | |
1628 | if (!hctx->ctxs) | |
1629 | break; | |
1630 | ||
1631 | if (blk_mq_alloc_bitmap(&hctx->ctx_map, node)) | |
1632 | break; | |
1633 | ||
1634 | hctx->nr_ctx = 0; | |
1635 | ||
1636 | if (set->ops->init_hctx && | |
1637 | set->ops->init_hctx(hctx, set->driver_data, i)) | |
1638 | break; | |
1639 | } | |
1640 | ||
1641 | if (i == q->nr_hw_queues) | |
1642 | return 0; | |
1643 | ||
1644 | /* | |
1645 | * Init failed | |
1646 | */ | |
1647 | blk_mq_exit_hw_queues(q, set, i); | |
1648 | ||
1649 | return 1; | |
1650 | } | |
1651 | ||
1652 | static void blk_mq_init_cpu_queues(struct request_queue *q, | |
1653 | unsigned int nr_hw_queues) | |
1654 | { | |
1655 | unsigned int i; | |
1656 | ||
1657 | for_each_possible_cpu(i) { | |
1658 | struct blk_mq_ctx *__ctx = per_cpu_ptr(q->queue_ctx, i); | |
1659 | struct blk_mq_hw_ctx *hctx; | |
1660 | ||
1661 | memset(__ctx, 0, sizeof(*__ctx)); | |
1662 | __ctx->cpu = i; | |
1663 | spin_lock_init(&__ctx->lock); | |
1664 | INIT_LIST_HEAD(&__ctx->rq_list); | |
1665 | __ctx->queue = q; | |
1666 | ||
1667 | /* If the cpu isn't online, the cpu is mapped to first hctx */ | |
1668 | if (!cpu_online(i)) | |
1669 | continue; | |
1670 | ||
1671 | hctx = q->mq_ops->map_queue(q, i); | |
1672 | cpumask_set_cpu(i, hctx->cpumask); | |
1673 | hctx->nr_ctx++; | |
1674 | ||
1675 | /* | |
1676 | * Set local node, IFF we have more than one hw queue. If | |
1677 | * not, we remain on the home node of the device | |
1678 | */ | |
1679 | if (nr_hw_queues > 1 && hctx->numa_node == NUMA_NO_NODE) | |
1680 | hctx->numa_node = cpu_to_node(i); | |
1681 | } | |
1682 | } | |
1683 | ||
1684 | static void blk_mq_map_swqueue(struct request_queue *q) | |
1685 | { | |
1686 | unsigned int i; | |
1687 | struct blk_mq_hw_ctx *hctx; | |
1688 | struct blk_mq_ctx *ctx; | |
1689 | ||
1690 | queue_for_each_hw_ctx(q, hctx, i) { | |
1691 | cpumask_clear(hctx->cpumask); | |
1692 | hctx->nr_ctx = 0; | |
1693 | } | |
1694 | ||
1695 | /* | |
1696 | * Map software to hardware queues | |
1697 | */ | |
1698 | queue_for_each_ctx(q, ctx, i) { | |
1699 | /* If the cpu isn't online, the cpu is mapped to first hctx */ | |
1700 | if (!cpu_online(i)) | |
1701 | continue; | |
1702 | ||
1703 | hctx = q->mq_ops->map_queue(q, i); | |
1704 | cpumask_set_cpu(i, hctx->cpumask); | |
1705 | ctx->index_hw = hctx->nr_ctx; | |
1706 | hctx->ctxs[hctx->nr_ctx++] = ctx; | |
1707 | } | |
1708 | ||
1709 | queue_for_each_hw_ctx(q, hctx, i) { | |
1710 | /* | |
1711 | * If not software queues are mapped to this hardware queue, | |
1712 | * disable it and free the request entries | |
1713 | */ | |
1714 | if (!hctx->nr_ctx) { | |
1715 | struct blk_mq_tag_set *set = q->tag_set; | |
1716 | ||
1717 | if (set->tags[i]) { | |
1718 | blk_mq_free_rq_map(set, set->tags[i], i); | |
1719 | set->tags[i] = NULL; | |
1720 | hctx->tags = NULL; | |
1721 | } | |
1722 | continue; | |
1723 | } | |
1724 | ||
1725 | /* | |
1726 | * Initialize batch roundrobin counts | |
1727 | */ | |
1728 | hctx->next_cpu = cpumask_first(hctx->cpumask); | |
1729 | hctx->next_cpu_batch = BLK_MQ_CPU_WORK_BATCH; | |
1730 | } | |
1731 | } | |
1732 | ||
1733 | static void blk_mq_update_tag_set_depth(struct blk_mq_tag_set *set) | |
1734 | { | |
1735 | struct blk_mq_hw_ctx *hctx; | |
1736 | struct request_queue *q; | |
1737 | bool shared; | |
1738 | int i; | |
1739 | ||
1740 | if (set->tag_list.next == set->tag_list.prev) | |
1741 | shared = false; | |
1742 | else | |
1743 | shared = true; | |
1744 | ||
1745 | list_for_each_entry(q, &set->tag_list, tag_set_list) { | |
1746 | blk_mq_freeze_queue(q); | |
1747 | ||
1748 | queue_for_each_hw_ctx(q, hctx, i) { | |
1749 | if (shared) | |
1750 | hctx->flags |= BLK_MQ_F_TAG_SHARED; | |
1751 | else | |
1752 | hctx->flags &= ~BLK_MQ_F_TAG_SHARED; | |
1753 | } | |
1754 | blk_mq_unfreeze_queue(q); | |
1755 | } | |
1756 | } | |
1757 | ||
1758 | static void blk_mq_del_queue_tag_set(struct request_queue *q) | |
1759 | { | |
1760 | struct blk_mq_tag_set *set = q->tag_set; | |
1761 | ||
1762 | blk_mq_freeze_queue(q); | |
1763 | ||
1764 | mutex_lock(&set->tag_list_lock); | |
1765 | list_del_init(&q->tag_set_list); | |
1766 | blk_mq_update_tag_set_depth(set); | |
1767 | mutex_unlock(&set->tag_list_lock); | |
1768 | ||
1769 | blk_mq_unfreeze_queue(q); | |
1770 | } | |
1771 | ||
1772 | static void blk_mq_add_queue_tag_set(struct blk_mq_tag_set *set, | |
1773 | struct request_queue *q) | |
1774 | { | |
1775 | q->tag_set = set; | |
1776 | ||
1777 | mutex_lock(&set->tag_list_lock); | |
1778 | list_add_tail(&q->tag_set_list, &set->tag_list); | |
1779 | blk_mq_update_tag_set_depth(set); | |
1780 | mutex_unlock(&set->tag_list_lock); | |
1781 | } | |
1782 | ||
1783 | struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *set) | |
1784 | { | |
1785 | struct blk_mq_hw_ctx **hctxs; | |
1786 | struct blk_mq_ctx *ctx; | |
1787 | struct request_queue *q; | |
1788 | unsigned int *map; | |
1789 | int i; | |
1790 | ||
1791 | ctx = alloc_percpu(struct blk_mq_ctx); | |
1792 | if (!ctx) | |
1793 | return ERR_PTR(-ENOMEM); | |
1794 | ||
1795 | hctxs = kmalloc_node(set->nr_hw_queues * sizeof(*hctxs), GFP_KERNEL, | |
1796 | set->numa_node); | |
1797 | ||
1798 | if (!hctxs) | |
1799 | goto err_percpu; | |
1800 | ||
1801 | map = blk_mq_make_queue_map(set); | |
1802 | if (!map) | |
1803 | goto err_map; | |
1804 | ||
1805 | for (i = 0; i < set->nr_hw_queues; i++) { | |
1806 | int node = blk_mq_hw_queue_to_node(map, i); | |
1807 | ||
1808 | hctxs[i] = set->ops->alloc_hctx(set, i, node); | |
1809 | if (!hctxs[i]) | |
1810 | goto err_hctxs; | |
1811 | ||
1812 | if (!zalloc_cpumask_var(&hctxs[i]->cpumask, GFP_KERNEL)) | |
1813 | goto err_hctxs; | |
1814 | ||
1815 | atomic_set(&hctxs[i]->nr_active, 0); | |
1816 | hctxs[i]->numa_node = node; | |
1817 | hctxs[i]->queue_num = i; | |
1818 | } | |
1819 | ||
1820 | q = blk_alloc_queue_node(GFP_KERNEL, set->numa_node); | |
1821 | if (!q) | |
1822 | goto err_hctxs; | |
1823 | ||
1824 | if (percpu_counter_init(&q->mq_usage_counter, 0)) | |
1825 | goto err_map; | |
1826 | ||
1827 | setup_timer(&q->timeout, blk_mq_rq_timer, (unsigned long) q); | |
1828 | blk_queue_rq_timeout(q, 30000); | |
1829 | ||
1830 | q->nr_queues = nr_cpu_ids; | |
1831 | q->nr_hw_queues = set->nr_hw_queues; | |
1832 | q->mq_map = map; | |
1833 | ||
1834 | q->queue_ctx = ctx; | |
1835 | q->queue_hw_ctx = hctxs; | |
1836 | ||
1837 | q->mq_ops = set->ops; | |
1838 | q->queue_flags |= QUEUE_FLAG_MQ_DEFAULT; | |
1839 | ||
1840 | q->sg_reserved_size = INT_MAX; | |
1841 | ||
1842 | INIT_WORK(&q->requeue_work, blk_mq_requeue_work); | |
1843 | INIT_LIST_HEAD(&q->requeue_list); | |
1844 | spin_lock_init(&q->requeue_lock); | |
1845 | ||
1846 | if (q->nr_hw_queues > 1) | |
1847 | blk_queue_make_request(q, blk_mq_make_request); | |
1848 | else | |
1849 | blk_queue_make_request(q, blk_sq_make_request); | |
1850 | ||
1851 | blk_queue_rq_timed_out(q, blk_mq_rq_timed_out); | |
1852 | if (set->timeout) | |
1853 | blk_queue_rq_timeout(q, set->timeout); | |
1854 | ||
1855 | /* | |
1856 | * Do this after blk_queue_make_request() overrides it... | |
1857 | */ | |
1858 | q->nr_requests = set->queue_depth; | |
1859 | ||
1860 | if (set->ops->complete) | |
1861 | blk_queue_softirq_done(q, set->ops->complete); | |
1862 | ||
1863 | blk_mq_init_flush(q); | |
1864 | blk_mq_init_cpu_queues(q, set->nr_hw_queues); | |
1865 | ||
1866 | q->flush_rq = kzalloc(round_up(sizeof(struct request) + | |
1867 | set->cmd_size, cache_line_size()), | |
1868 | GFP_KERNEL); | |
1869 | if (!q->flush_rq) | |
1870 | goto err_hw; | |
1871 | ||
1872 | if (blk_mq_init_hw_queues(q, set)) | |
1873 | goto err_flush_rq; | |
1874 | ||
1875 | mutex_lock(&all_q_mutex); | |
1876 | list_add_tail(&q->all_q_node, &all_q_list); | |
1877 | mutex_unlock(&all_q_mutex); | |
1878 | ||
1879 | blk_mq_add_queue_tag_set(set, q); | |
1880 | ||
1881 | blk_mq_map_swqueue(q); | |
1882 | ||
1883 | return q; | |
1884 | ||
1885 | err_flush_rq: | |
1886 | kfree(q->flush_rq); | |
1887 | err_hw: | |
1888 | blk_cleanup_queue(q); | |
1889 | err_hctxs: | |
1890 | kfree(map); | |
1891 | for (i = 0; i < set->nr_hw_queues; i++) { | |
1892 | if (!hctxs[i]) | |
1893 | break; | |
1894 | free_cpumask_var(hctxs[i]->cpumask); | |
1895 | set->ops->free_hctx(hctxs[i], i); | |
1896 | } | |
1897 | err_map: | |
1898 | kfree(hctxs); | |
1899 | err_percpu: | |
1900 | free_percpu(ctx); | |
1901 | return ERR_PTR(-ENOMEM); | |
1902 | } | |
1903 | EXPORT_SYMBOL(blk_mq_init_queue); | |
1904 | ||
1905 | void blk_mq_free_queue(struct request_queue *q) | |
1906 | { | |
1907 | struct blk_mq_tag_set *set = q->tag_set; | |
1908 | ||
1909 | blk_mq_del_queue_tag_set(q); | |
1910 | ||
1911 | blk_mq_exit_hw_queues(q, set, set->nr_hw_queues); | |
1912 | blk_mq_free_hw_queues(q, set); | |
1913 | ||
1914 | percpu_counter_destroy(&q->mq_usage_counter); | |
1915 | ||
1916 | free_percpu(q->queue_ctx); | |
1917 | kfree(q->queue_hw_ctx); | |
1918 | kfree(q->mq_map); | |
1919 | ||
1920 | q->queue_ctx = NULL; | |
1921 | q->queue_hw_ctx = NULL; | |
1922 | q->mq_map = NULL; | |
1923 | ||
1924 | mutex_lock(&all_q_mutex); | |
1925 | list_del_init(&q->all_q_node); | |
1926 | mutex_unlock(&all_q_mutex); | |
1927 | } | |
1928 | ||
1929 | /* Basically redo blk_mq_init_queue with queue frozen */ | |
1930 | static void blk_mq_queue_reinit(struct request_queue *q) | |
1931 | { | |
1932 | blk_mq_freeze_queue(q); | |
1933 | ||
1934 | blk_mq_update_queue_map(q->mq_map, q->nr_hw_queues); | |
1935 | ||
1936 | /* | |
1937 | * redo blk_mq_init_cpu_queues and blk_mq_init_hw_queues. FIXME: maybe | |
1938 | * we should change hctx numa_node according to new topology (this | |
1939 | * involves free and re-allocate memory, worthy doing?) | |
1940 | */ | |
1941 | ||
1942 | blk_mq_map_swqueue(q); | |
1943 | ||
1944 | blk_mq_unfreeze_queue(q); | |
1945 | } | |
1946 | ||
1947 | static int blk_mq_queue_reinit_notify(struct notifier_block *nb, | |
1948 | unsigned long action, void *hcpu) | |
1949 | { | |
1950 | struct request_queue *q; | |
1951 | ||
1952 | /* | |
1953 | * Before new mappings are established, hotadded cpu might already | |
1954 | * start handling requests. This doesn't break anything as we map | |
1955 | * offline CPUs to first hardware queue. We will re-init the queue | |
1956 | * below to get optimal settings. | |
1957 | */ | |
1958 | if (action != CPU_DEAD && action != CPU_DEAD_FROZEN && | |
1959 | action != CPU_ONLINE && action != CPU_ONLINE_FROZEN) | |
1960 | return NOTIFY_OK; | |
1961 | ||
1962 | mutex_lock(&all_q_mutex); | |
1963 | list_for_each_entry(q, &all_q_list, all_q_node) | |
1964 | blk_mq_queue_reinit(q); | |
1965 | mutex_unlock(&all_q_mutex); | |
1966 | return NOTIFY_OK; | |
1967 | } | |
1968 | ||
1969 | int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set) | |
1970 | { | |
1971 | int i; | |
1972 | ||
1973 | if (!set->nr_hw_queues) | |
1974 | return -EINVAL; | |
1975 | if (!set->queue_depth || set->queue_depth > BLK_MQ_MAX_DEPTH) | |
1976 | return -EINVAL; | |
1977 | if (set->queue_depth < set->reserved_tags + BLK_MQ_TAG_MIN) | |
1978 | return -EINVAL; | |
1979 | ||
1980 | if (!set->nr_hw_queues || | |
1981 | !set->ops->queue_rq || !set->ops->map_queue || | |
1982 | !set->ops->alloc_hctx || !set->ops->free_hctx) | |
1983 | return -EINVAL; | |
1984 | ||
1985 | ||
1986 | set->tags = kmalloc_node(set->nr_hw_queues * | |
1987 | sizeof(struct blk_mq_tags *), | |
1988 | GFP_KERNEL, set->numa_node); | |
1989 | if (!set->tags) | |
1990 | goto out; | |
1991 | ||
1992 | for (i = 0; i < set->nr_hw_queues; i++) { | |
1993 | set->tags[i] = blk_mq_init_rq_map(set, i); | |
1994 | if (!set->tags[i]) | |
1995 | goto out_unwind; | |
1996 | } | |
1997 | ||
1998 | mutex_init(&set->tag_list_lock); | |
1999 | INIT_LIST_HEAD(&set->tag_list); | |
2000 | ||
2001 | return 0; | |
2002 | ||
2003 | out_unwind: | |
2004 | while (--i >= 0) | |
2005 | blk_mq_free_rq_map(set, set->tags[i], i); | |
2006 | out: | |
2007 | return -ENOMEM; | |
2008 | } | |
2009 | EXPORT_SYMBOL(blk_mq_alloc_tag_set); | |
2010 | ||
2011 | void blk_mq_free_tag_set(struct blk_mq_tag_set *set) | |
2012 | { | |
2013 | int i; | |
2014 | ||
2015 | for (i = 0; i < set->nr_hw_queues; i++) { | |
2016 | if (set->tags[i]) | |
2017 | blk_mq_free_rq_map(set, set->tags[i], i); | |
2018 | } | |
2019 | ||
2020 | kfree(set->tags); | |
2021 | } | |
2022 | EXPORT_SYMBOL(blk_mq_free_tag_set); | |
2023 | ||
2024 | int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr) | |
2025 | { | |
2026 | struct blk_mq_tag_set *set = q->tag_set; | |
2027 | struct blk_mq_hw_ctx *hctx; | |
2028 | int i, ret; | |
2029 | ||
2030 | if (!set || nr > set->queue_depth) | |
2031 | return -EINVAL; | |
2032 | ||
2033 | ret = 0; | |
2034 | queue_for_each_hw_ctx(q, hctx, i) { | |
2035 | ret = blk_mq_tag_update_depth(hctx->tags, nr); | |
2036 | if (ret) | |
2037 | break; | |
2038 | } | |
2039 | ||
2040 | if (!ret) | |
2041 | q->nr_requests = nr; | |
2042 | ||
2043 | return ret; | |
2044 | } | |
2045 | ||
2046 | void blk_mq_disable_hotplug(void) | |
2047 | { | |
2048 | mutex_lock(&all_q_mutex); | |
2049 | } | |
2050 | ||
2051 | void blk_mq_enable_hotplug(void) | |
2052 | { | |
2053 | mutex_unlock(&all_q_mutex); | |
2054 | } | |
2055 | ||
2056 | static int __init blk_mq_init(void) | |
2057 | { | |
2058 | blk_mq_cpu_init(); | |
2059 | ||
2060 | /* Must be called after percpu_counter_hotcpu_callback() */ | |
2061 | hotcpu_notifier(blk_mq_queue_reinit_notify, -10); | |
2062 | ||
2063 | return 0; | |
2064 | } | |
2065 | subsys_initcall(blk_mq_init); |