Commit | Line | Data |
---|---|---|
75bb4625 JA |
1 | /* |
2 | * Block multiqueue core code | |
3 | * | |
4 | * Copyright (C) 2013-2014 Jens Axboe | |
5 | * Copyright (C) 2013-2014 Christoph Hellwig | |
6 | */ | |
320ae51f JA |
7 | #include <linux/kernel.h> |
8 | #include <linux/module.h> | |
9 | #include <linux/backing-dev.h> | |
10 | #include <linux/bio.h> | |
11 | #include <linux/blkdev.h> | |
12 | #include <linux/mm.h> | |
13 | #include <linux/init.h> | |
14 | #include <linux/slab.h> | |
15 | #include <linux/workqueue.h> | |
16 | #include <linux/smp.h> | |
17 | #include <linux/llist.h> | |
18 | #include <linux/list_sort.h> | |
19 | #include <linux/cpu.h> | |
20 | #include <linux/cache.h> | |
21 | #include <linux/sched/sysctl.h> | |
22 | #include <linux/delay.h> | |
23 | ||
24 | #include <trace/events/block.h> | |
25 | ||
26 | #include <linux/blk-mq.h> | |
27 | #include "blk.h" | |
28 | #include "blk-mq.h" | |
29 | #include "blk-mq-tag.h" | |
30 | ||
31 | static DEFINE_MUTEX(all_q_mutex); | |
32 | static LIST_HEAD(all_q_list); | |
33 | ||
34 | static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx); | |
35 | ||
320ae51f JA |
36 | /* |
37 | * Check if any of the ctx's have pending work in this hardware queue | |
38 | */ | |
39 | static bool blk_mq_hctx_has_pending(struct blk_mq_hw_ctx *hctx) | |
40 | { | |
41 | unsigned int i; | |
42 | ||
1429d7c9 JA |
43 | for (i = 0; i < hctx->ctx_map.map_size; i++) |
44 | if (hctx->ctx_map.map[i].word) | |
320ae51f JA |
45 | return true; |
46 | ||
47 | return false; | |
48 | } | |
49 | ||
1429d7c9 JA |
50 | static inline struct blk_align_bitmap *get_bm(struct blk_mq_hw_ctx *hctx, |
51 | struct blk_mq_ctx *ctx) | |
52 | { | |
53 | return &hctx->ctx_map.map[ctx->index_hw / hctx->ctx_map.bits_per_word]; | |
54 | } | |
55 | ||
56 | #define CTX_TO_BIT(hctx, ctx) \ | |
57 | ((ctx)->index_hw & ((hctx)->ctx_map.bits_per_word - 1)) | |
58 | ||
320ae51f JA |
59 | /* |
60 | * Mark this ctx as having pending work in this hardware queue | |
61 | */ | |
62 | static void blk_mq_hctx_mark_pending(struct blk_mq_hw_ctx *hctx, | |
63 | struct blk_mq_ctx *ctx) | |
64 | { | |
1429d7c9 JA |
65 | struct blk_align_bitmap *bm = get_bm(hctx, ctx); |
66 | ||
67 | if (!test_bit(CTX_TO_BIT(hctx, ctx), &bm->word)) | |
68 | set_bit(CTX_TO_BIT(hctx, ctx), &bm->word); | |
69 | } | |
70 | ||
71 | static void blk_mq_hctx_clear_pending(struct blk_mq_hw_ctx *hctx, | |
72 | struct blk_mq_ctx *ctx) | |
73 | { | |
74 | struct blk_align_bitmap *bm = get_bm(hctx, ctx); | |
75 | ||
76 | clear_bit(CTX_TO_BIT(hctx, ctx), &bm->word); | |
320ae51f JA |
77 | } |
78 | ||
320ae51f JA |
79 | static int blk_mq_queue_enter(struct request_queue *q) |
80 | { | |
add703fd TH |
81 | while (true) { |
82 | int ret; | |
320ae51f | 83 | |
add703fd TH |
84 | if (percpu_ref_tryget_live(&q->mq_usage_counter)) |
85 | return 0; | |
320ae51f | 86 | |
add703fd TH |
87 | ret = wait_event_interruptible(q->mq_freeze_wq, |
88 | !q->mq_freeze_depth || blk_queue_dying(q)); | |
89 | if (blk_queue_dying(q)) | |
90 | return -ENODEV; | |
91 | if (ret) | |
92 | return ret; | |
93 | } | |
320ae51f JA |
94 | } |
95 | ||
96 | static void blk_mq_queue_exit(struct request_queue *q) | |
97 | { | |
add703fd TH |
98 | percpu_ref_put(&q->mq_usage_counter); |
99 | } | |
100 | ||
101 | static void blk_mq_usage_counter_release(struct percpu_ref *ref) | |
102 | { | |
103 | struct request_queue *q = | |
104 | container_of(ref, struct request_queue, mq_usage_counter); | |
105 | ||
106 | wake_up_all(&q->mq_freeze_wq); | |
320ae51f JA |
107 | } |
108 | ||
72d6f02a TH |
109 | /* |
110 | * Guarantee no request is in use, so we can change any data structure of | |
111 | * the queue afterward. | |
112 | */ | |
113 | void blk_mq_freeze_queue(struct request_queue *q) | |
43a5e4e2 | 114 | { |
cddd5d17 TH |
115 | bool freeze; |
116 | ||
72d6f02a | 117 | spin_lock_irq(q->queue_lock); |
cddd5d17 | 118 | freeze = !q->mq_freeze_depth++; |
72d6f02a TH |
119 | spin_unlock_irq(q->queue_lock); |
120 | ||
cddd5d17 TH |
121 | if (freeze) { |
122 | percpu_ref_kill(&q->mq_usage_counter); | |
123 | blk_mq_run_queues(q, false); | |
124 | } | |
add703fd | 125 | wait_event(q->mq_freeze_wq, percpu_ref_is_zero(&q->mq_usage_counter)); |
43a5e4e2 ML |
126 | } |
127 | ||
320ae51f JA |
128 | static void blk_mq_unfreeze_queue(struct request_queue *q) |
129 | { | |
cddd5d17 | 130 | bool wake; |
320ae51f JA |
131 | |
132 | spin_lock_irq(q->queue_lock); | |
780db207 TH |
133 | wake = !--q->mq_freeze_depth; |
134 | WARN_ON_ONCE(q->mq_freeze_depth < 0); | |
320ae51f | 135 | spin_unlock_irq(q->queue_lock); |
add703fd TH |
136 | if (wake) { |
137 | percpu_ref_reinit(&q->mq_usage_counter); | |
320ae51f | 138 | wake_up_all(&q->mq_freeze_wq); |
add703fd | 139 | } |
320ae51f JA |
140 | } |
141 | ||
142 | bool blk_mq_can_queue(struct blk_mq_hw_ctx *hctx) | |
143 | { | |
144 | return blk_mq_has_free_tags(hctx->tags); | |
145 | } | |
146 | EXPORT_SYMBOL(blk_mq_can_queue); | |
147 | ||
94eddfbe JA |
148 | static void blk_mq_rq_ctx_init(struct request_queue *q, struct blk_mq_ctx *ctx, |
149 | struct request *rq, unsigned int rw_flags) | |
320ae51f | 150 | { |
94eddfbe JA |
151 | if (blk_queue_io_stat(q)) |
152 | rw_flags |= REQ_IO_STAT; | |
153 | ||
af76e555 CH |
154 | INIT_LIST_HEAD(&rq->queuelist); |
155 | /* csd/requeue_work/fifo_time is initialized before use */ | |
156 | rq->q = q; | |
320ae51f | 157 | rq->mq_ctx = ctx; |
0d2602ca | 158 | rq->cmd_flags |= rw_flags; |
af76e555 CH |
159 | /* do not touch atomic flags, it needs atomic ops against the timer */ |
160 | rq->cpu = -1; | |
af76e555 CH |
161 | INIT_HLIST_NODE(&rq->hash); |
162 | RB_CLEAR_NODE(&rq->rb_node); | |
af76e555 CH |
163 | rq->rq_disk = NULL; |
164 | rq->part = NULL; | |
3ee32372 | 165 | rq->start_time = jiffies; |
af76e555 CH |
166 | #ifdef CONFIG_BLK_CGROUP |
167 | rq->rl = NULL; | |
0fec08b4 | 168 | set_start_time_ns(rq); |
af76e555 CH |
169 | rq->io_start_time_ns = 0; |
170 | #endif | |
171 | rq->nr_phys_segments = 0; | |
172 | #if defined(CONFIG_BLK_DEV_INTEGRITY) | |
173 | rq->nr_integrity_segments = 0; | |
174 | #endif | |
af76e555 CH |
175 | rq->special = NULL; |
176 | /* tag was already set */ | |
177 | rq->errors = 0; | |
af76e555 | 178 | |
6f4a1626 TB |
179 | rq->cmd = rq->__cmd; |
180 | ||
af76e555 CH |
181 | rq->extra_len = 0; |
182 | rq->sense_len = 0; | |
183 | rq->resid_len = 0; | |
184 | rq->sense = NULL; | |
185 | ||
af76e555 | 186 | INIT_LIST_HEAD(&rq->timeout_list); |
f6be4fb4 JA |
187 | rq->timeout = 0; |
188 | ||
af76e555 CH |
189 | rq->end_io = NULL; |
190 | rq->end_io_data = NULL; | |
191 | rq->next_rq = NULL; | |
192 | ||
320ae51f JA |
193 | ctx->rq_dispatched[rw_is_sync(rw_flags)]++; |
194 | } | |
195 | ||
5dee8577 | 196 | static struct request * |
cb96a42c | 197 | __blk_mq_alloc_request(struct blk_mq_alloc_data *data, int rw) |
5dee8577 CH |
198 | { |
199 | struct request *rq; | |
200 | unsigned int tag; | |
201 | ||
cb96a42c | 202 | tag = blk_mq_get_tag(data); |
5dee8577 | 203 | if (tag != BLK_MQ_TAG_FAIL) { |
cb96a42c | 204 | rq = data->hctx->tags->rqs[tag]; |
5dee8577 CH |
205 | |
206 | rq->cmd_flags = 0; | |
cb96a42c | 207 | if (blk_mq_tag_busy(data->hctx)) { |
5dee8577 | 208 | rq->cmd_flags = REQ_MQ_INFLIGHT; |
cb96a42c | 209 | atomic_inc(&data->hctx->nr_active); |
5dee8577 CH |
210 | } |
211 | ||
212 | rq->tag = tag; | |
cb96a42c | 213 | blk_mq_rq_ctx_init(data->q, data->ctx, rq, rw); |
5dee8577 CH |
214 | return rq; |
215 | } | |
216 | ||
217 | return NULL; | |
218 | } | |
219 | ||
4ce01dd1 CH |
220 | struct request *blk_mq_alloc_request(struct request_queue *q, int rw, gfp_t gfp, |
221 | bool reserved) | |
320ae51f | 222 | { |
d852564f CH |
223 | struct blk_mq_ctx *ctx; |
224 | struct blk_mq_hw_ctx *hctx; | |
320ae51f | 225 | struct request *rq; |
cb96a42c | 226 | struct blk_mq_alloc_data alloc_data; |
320ae51f JA |
227 | |
228 | if (blk_mq_queue_enter(q)) | |
229 | return NULL; | |
230 | ||
d852564f CH |
231 | ctx = blk_mq_get_ctx(q); |
232 | hctx = q->mq_ops->map_queue(q, ctx->cpu); | |
cb96a42c ML |
233 | blk_mq_set_alloc_data(&alloc_data, q, gfp & ~__GFP_WAIT, |
234 | reserved, ctx, hctx); | |
d852564f | 235 | |
cb96a42c | 236 | rq = __blk_mq_alloc_request(&alloc_data, rw); |
d852564f CH |
237 | if (!rq && (gfp & __GFP_WAIT)) { |
238 | __blk_mq_run_hw_queue(hctx); | |
239 | blk_mq_put_ctx(ctx); | |
240 | ||
241 | ctx = blk_mq_get_ctx(q); | |
242 | hctx = q->mq_ops->map_queue(q, ctx->cpu); | |
cb96a42c ML |
243 | blk_mq_set_alloc_data(&alloc_data, q, gfp, reserved, ctx, |
244 | hctx); | |
245 | rq = __blk_mq_alloc_request(&alloc_data, rw); | |
246 | ctx = alloc_data.ctx; | |
d852564f CH |
247 | } |
248 | blk_mq_put_ctx(ctx); | |
320ae51f JA |
249 | return rq; |
250 | } | |
4bb659b1 | 251 | EXPORT_SYMBOL(blk_mq_alloc_request); |
320ae51f | 252 | |
320ae51f JA |
253 | static void __blk_mq_free_request(struct blk_mq_hw_ctx *hctx, |
254 | struct blk_mq_ctx *ctx, struct request *rq) | |
255 | { | |
256 | const int tag = rq->tag; | |
257 | struct request_queue *q = rq->q; | |
258 | ||
0d2602ca JA |
259 | if (rq->cmd_flags & REQ_MQ_INFLIGHT) |
260 | atomic_dec(&hctx->nr_active); | |
261 | ||
af76e555 | 262 | clear_bit(REQ_ATOM_STARTED, &rq->atomic_flags); |
0d2602ca | 263 | blk_mq_put_tag(hctx, tag, &ctx->last_tag); |
320ae51f JA |
264 | blk_mq_queue_exit(q); |
265 | } | |
266 | ||
267 | void blk_mq_free_request(struct request *rq) | |
268 | { | |
269 | struct blk_mq_ctx *ctx = rq->mq_ctx; | |
270 | struct blk_mq_hw_ctx *hctx; | |
271 | struct request_queue *q = rq->q; | |
272 | ||
273 | ctx->rq_completed[rq_is_sync(rq)]++; | |
274 | ||
275 | hctx = q->mq_ops->map_queue(q, ctx->cpu); | |
276 | __blk_mq_free_request(hctx, ctx, rq); | |
277 | } | |
278 | ||
8727af4b CH |
279 | /* |
280 | * Clone all relevant state from a request that has been put on hold in | |
281 | * the flush state machine into the preallocated flush request that hangs | |
282 | * off the request queue. | |
283 | * | |
284 | * For a driver the flush request should be invisible, that's why we are | |
285 | * impersonating the original request here. | |
286 | */ | |
287 | void blk_mq_clone_flush_request(struct request *flush_rq, | |
288 | struct request *orig_rq) | |
289 | { | |
290 | struct blk_mq_hw_ctx *hctx = | |
291 | orig_rq->q->mq_ops->map_queue(orig_rq->q, orig_rq->mq_ctx->cpu); | |
292 | ||
293 | flush_rq->mq_ctx = orig_rq->mq_ctx; | |
294 | flush_rq->tag = orig_rq->tag; | |
295 | memcpy(blk_mq_rq_to_pdu(flush_rq), blk_mq_rq_to_pdu(orig_rq), | |
296 | hctx->cmd_size); | |
297 | } | |
298 | ||
63151a44 | 299 | inline void __blk_mq_end_io(struct request *rq, int error) |
320ae51f | 300 | { |
0d11e6ac ML |
301 | blk_account_io_done(rq); |
302 | ||
91b63639 | 303 | if (rq->end_io) { |
320ae51f | 304 | rq->end_io(rq, error); |
91b63639 CH |
305 | } else { |
306 | if (unlikely(blk_bidi_rq(rq))) | |
307 | blk_mq_free_request(rq->next_rq); | |
320ae51f | 308 | blk_mq_free_request(rq); |
91b63639 | 309 | } |
320ae51f | 310 | } |
63151a44 CH |
311 | EXPORT_SYMBOL(__blk_mq_end_io); |
312 | ||
313 | void blk_mq_end_io(struct request *rq, int error) | |
314 | { | |
315 | if (blk_update_request(rq, error, blk_rq_bytes(rq))) | |
316 | BUG(); | |
317 | __blk_mq_end_io(rq, error); | |
318 | } | |
319 | EXPORT_SYMBOL(blk_mq_end_io); | |
320ae51f | 320 | |
30a91cb4 | 321 | static void __blk_mq_complete_request_remote(void *data) |
320ae51f | 322 | { |
3d6efbf6 | 323 | struct request *rq = data; |
320ae51f | 324 | |
30a91cb4 | 325 | rq->q->softirq_done_fn(rq); |
320ae51f | 326 | } |
320ae51f | 327 | |
ed851860 | 328 | static void blk_mq_ipi_complete_request(struct request *rq) |
320ae51f JA |
329 | { |
330 | struct blk_mq_ctx *ctx = rq->mq_ctx; | |
38535201 | 331 | bool shared = false; |
320ae51f JA |
332 | int cpu; |
333 | ||
38535201 | 334 | if (!test_bit(QUEUE_FLAG_SAME_COMP, &rq->q->queue_flags)) { |
30a91cb4 CH |
335 | rq->q->softirq_done_fn(rq); |
336 | return; | |
337 | } | |
320ae51f JA |
338 | |
339 | cpu = get_cpu(); | |
38535201 CH |
340 | if (!test_bit(QUEUE_FLAG_SAME_FORCE, &rq->q->queue_flags)) |
341 | shared = cpus_share_cache(cpu, ctx->cpu); | |
342 | ||
343 | if (cpu != ctx->cpu && !shared && cpu_online(ctx->cpu)) { | |
30a91cb4 | 344 | rq->csd.func = __blk_mq_complete_request_remote; |
3d6efbf6 CH |
345 | rq->csd.info = rq; |
346 | rq->csd.flags = 0; | |
c46fff2a | 347 | smp_call_function_single_async(ctx->cpu, &rq->csd); |
3d6efbf6 | 348 | } else { |
30a91cb4 | 349 | rq->q->softirq_done_fn(rq); |
3d6efbf6 | 350 | } |
320ae51f JA |
351 | put_cpu(); |
352 | } | |
30a91cb4 | 353 | |
ed851860 JA |
354 | void __blk_mq_complete_request(struct request *rq) |
355 | { | |
356 | struct request_queue *q = rq->q; | |
357 | ||
358 | if (!q->softirq_done_fn) | |
359 | blk_mq_end_io(rq, rq->errors); | |
360 | else | |
361 | blk_mq_ipi_complete_request(rq); | |
362 | } | |
363 | ||
30a91cb4 CH |
364 | /** |
365 | * blk_mq_complete_request - end I/O on a request | |
366 | * @rq: the request being processed | |
367 | * | |
368 | * Description: | |
369 | * Ends all I/O on a request. It does not handle partial completions. | |
370 | * The actual completion happens out-of-order, through a IPI handler. | |
371 | **/ | |
372 | void blk_mq_complete_request(struct request *rq) | |
373 | { | |
95f09684 JA |
374 | struct request_queue *q = rq->q; |
375 | ||
376 | if (unlikely(blk_should_fake_timeout(q))) | |
30a91cb4 | 377 | return; |
ed851860 JA |
378 | if (!blk_mark_rq_complete(rq)) |
379 | __blk_mq_complete_request(rq); | |
30a91cb4 CH |
380 | } |
381 | EXPORT_SYMBOL(blk_mq_complete_request); | |
320ae51f | 382 | |
49f5baa5 | 383 | static void blk_mq_start_request(struct request *rq, bool last) |
320ae51f JA |
384 | { |
385 | struct request_queue *q = rq->q; | |
386 | ||
387 | trace_block_rq_issue(q, rq); | |
388 | ||
742ee69b | 389 | rq->resid_len = blk_rq_bytes(rq); |
91b63639 CH |
390 | if (unlikely(blk_bidi_rq(rq))) |
391 | rq->next_rq->resid_len = blk_rq_bytes(rq->next_rq); | |
742ee69b | 392 | |
2b8393b4 | 393 | blk_add_timer(rq); |
87ee7b11 JA |
394 | |
395 | /* | |
396 | * Mark us as started and clear complete. Complete might have been | |
397 | * set if requeue raced with timeout, which then marked it as | |
398 | * complete. So be sure to clear complete again when we start | |
399 | * the request, otherwise we'll ignore the completion event. | |
400 | */ | |
4b570521 JA |
401 | if (!test_bit(REQ_ATOM_STARTED, &rq->atomic_flags)) |
402 | set_bit(REQ_ATOM_STARTED, &rq->atomic_flags); | |
403 | if (test_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags)) | |
404 | clear_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags); | |
49f5baa5 CH |
405 | |
406 | if (q->dma_drain_size && blk_rq_bytes(rq)) { | |
407 | /* | |
408 | * Make sure space for the drain appears. We know we can do | |
409 | * this because max_hw_segments has been adjusted to be one | |
410 | * fewer than the device can handle. | |
411 | */ | |
412 | rq->nr_phys_segments++; | |
413 | } | |
414 | ||
415 | /* | |
416 | * Flag the last request in the series so that drivers know when IO | |
417 | * should be kicked off, if they don't do it on a per-request basis. | |
418 | * | |
419 | * Note: the flag isn't the only condition drivers should do kick off. | |
420 | * If drive is busy, the last request might not have the bit set. | |
421 | */ | |
422 | if (last) | |
423 | rq->cmd_flags |= REQ_END; | |
320ae51f JA |
424 | } |
425 | ||
ed0791b2 | 426 | static void __blk_mq_requeue_request(struct request *rq) |
320ae51f JA |
427 | { |
428 | struct request_queue *q = rq->q; | |
429 | ||
430 | trace_block_rq_requeue(q, rq); | |
431 | clear_bit(REQ_ATOM_STARTED, &rq->atomic_flags); | |
49f5baa5 CH |
432 | |
433 | rq->cmd_flags &= ~REQ_END; | |
434 | ||
435 | if (q->dma_drain_size && blk_rq_bytes(rq)) | |
436 | rq->nr_phys_segments--; | |
320ae51f JA |
437 | } |
438 | ||
ed0791b2 CH |
439 | void blk_mq_requeue_request(struct request *rq) |
440 | { | |
ed0791b2 CH |
441 | __blk_mq_requeue_request(rq); |
442 | blk_clear_rq_complete(rq); | |
443 | ||
ed0791b2 | 444 | BUG_ON(blk_queued_rq(rq)); |
6fca6a61 | 445 | blk_mq_add_to_requeue_list(rq, true); |
ed0791b2 CH |
446 | } |
447 | EXPORT_SYMBOL(blk_mq_requeue_request); | |
448 | ||
6fca6a61 CH |
449 | static void blk_mq_requeue_work(struct work_struct *work) |
450 | { | |
451 | struct request_queue *q = | |
452 | container_of(work, struct request_queue, requeue_work); | |
453 | LIST_HEAD(rq_list); | |
454 | struct request *rq, *next; | |
455 | unsigned long flags; | |
456 | ||
457 | spin_lock_irqsave(&q->requeue_lock, flags); | |
458 | list_splice_init(&q->requeue_list, &rq_list); | |
459 | spin_unlock_irqrestore(&q->requeue_lock, flags); | |
460 | ||
461 | list_for_each_entry_safe(rq, next, &rq_list, queuelist) { | |
462 | if (!(rq->cmd_flags & REQ_SOFTBARRIER)) | |
463 | continue; | |
464 | ||
465 | rq->cmd_flags &= ~REQ_SOFTBARRIER; | |
466 | list_del_init(&rq->queuelist); | |
467 | blk_mq_insert_request(rq, true, false, false); | |
468 | } | |
469 | ||
470 | while (!list_empty(&rq_list)) { | |
471 | rq = list_entry(rq_list.next, struct request, queuelist); | |
472 | list_del_init(&rq->queuelist); | |
473 | blk_mq_insert_request(rq, false, false, false); | |
474 | } | |
475 | ||
476 | blk_mq_run_queues(q, false); | |
477 | } | |
478 | ||
479 | void blk_mq_add_to_requeue_list(struct request *rq, bool at_head) | |
480 | { | |
481 | struct request_queue *q = rq->q; | |
482 | unsigned long flags; | |
483 | ||
484 | /* | |
485 | * We abuse this flag that is otherwise used by the I/O scheduler to | |
486 | * request head insertation from the workqueue. | |
487 | */ | |
488 | BUG_ON(rq->cmd_flags & REQ_SOFTBARRIER); | |
489 | ||
490 | spin_lock_irqsave(&q->requeue_lock, flags); | |
491 | if (at_head) { | |
492 | rq->cmd_flags |= REQ_SOFTBARRIER; | |
493 | list_add(&rq->queuelist, &q->requeue_list); | |
494 | } else { | |
495 | list_add_tail(&rq->queuelist, &q->requeue_list); | |
496 | } | |
497 | spin_unlock_irqrestore(&q->requeue_lock, flags); | |
498 | } | |
499 | EXPORT_SYMBOL(blk_mq_add_to_requeue_list); | |
500 | ||
501 | void blk_mq_kick_requeue_list(struct request_queue *q) | |
502 | { | |
503 | kblockd_schedule_work(&q->requeue_work); | |
504 | } | |
505 | EXPORT_SYMBOL(blk_mq_kick_requeue_list); | |
506 | ||
0e62f51f | 507 | static inline bool is_flush_request(struct request *rq, unsigned int tag) |
24d2f903 | 508 | { |
0e62f51f JA |
509 | return ((rq->cmd_flags & REQ_FLUSH_SEQ) && |
510 | rq->q->flush_rq->tag == tag); | |
511 | } | |
512 | ||
513 | struct request *blk_mq_tag_to_rq(struct blk_mq_tags *tags, unsigned int tag) | |
514 | { | |
515 | struct request *rq = tags->rqs[tag]; | |
22302375 | 516 | |
0e62f51f JA |
517 | if (!is_flush_request(rq, tag)) |
518 | return rq; | |
22302375 | 519 | |
0e62f51f | 520 | return rq->q->flush_rq; |
24d2f903 CH |
521 | } |
522 | EXPORT_SYMBOL(blk_mq_tag_to_rq); | |
523 | ||
320ae51f JA |
524 | struct blk_mq_timeout_data { |
525 | struct blk_mq_hw_ctx *hctx; | |
526 | unsigned long *next; | |
527 | unsigned int *next_set; | |
528 | }; | |
529 | ||
530 | static void blk_mq_timeout_check(void *__data, unsigned long *free_tags) | |
531 | { | |
532 | struct blk_mq_timeout_data *data = __data; | |
533 | struct blk_mq_hw_ctx *hctx = data->hctx; | |
534 | unsigned int tag; | |
535 | ||
536 | /* It may not be in flight yet (this is where | |
537 | * the REQ_ATOMIC_STARTED flag comes in). The requests are | |
538 | * statically allocated, so we know it's always safe to access the | |
539 | * memory associated with a bit offset into ->rqs[]. | |
540 | */ | |
541 | tag = 0; | |
542 | do { | |
543 | struct request *rq; | |
544 | ||
24d2f903 CH |
545 | tag = find_next_zero_bit(free_tags, hctx->tags->nr_tags, tag); |
546 | if (tag >= hctx->tags->nr_tags) | |
320ae51f JA |
547 | break; |
548 | ||
0e62f51f | 549 | rq = blk_mq_tag_to_rq(hctx->tags, tag++); |
24d2f903 CH |
550 | if (rq->q != hctx->queue) |
551 | continue; | |
320ae51f JA |
552 | if (!test_bit(REQ_ATOM_STARTED, &rq->atomic_flags)) |
553 | continue; | |
554 | ||
555 | blk_rq_check_expired(rq, data->next, data->next_set); | |
556 | } while (1); | |
557 | } | |
558 | ||
559 | static void blk_mq_hw_ctx_check_timeout(struct blk_mq_hw_ctx *hctx, | |
560 | unsigned long *next, | |
561 | unsigned int *next_set) | |
562 | { | |
563 | struct blk_mq_timeout_data data = { | |
564 | .hctx = hctx, | |
565 | .next = next, | |
566 | .next_set = next_set, | |
567 | }; | |
568 | ||
569 | /* | |
570 | * Ask the tagging code to iterate busy requests, so we can | |
571 | * check them for timeout. | |
572 | */ | |
573 | blk_mq_tag_busy_iter(hctx->tags, blk_mq_timeout_check, &data); | |
574 | } | |
575 | ||
87ee7b11 JA |
576 | static enum blk_eh_timer_return blk_mq_rq_timed_out(struct request *rq) |
577 | { | |
578 | struct request_queue *q = rq->q; | |
579 | ||
580 | /* | |
581 | * We know that complete is set at this point. If STARTED isn't set | |
582 | * anymore, then the request isn't active and the "timeout" should | |
583 | * just be ignored. This can happen due to the bitflag ordering. | |
584 | * Timeout first checks if STARTED is set, and if it is, assumes | |
585 | * the request is active. But if we race with completion, then | |
586 | * we both flags will get cleared. So check here again, and ignore | |
587 | * a timeout event with a request that isn't active. | |
588 | */ | |
589 | if (!test_bit(REQ_ATOM_STARTED, &rq->atomic_flags)) | |
590 | return BLK_EH_NOT_HANDLED; | |
591 | ||
592 | if (!q->mq_ops->timeout) | |
593 | return BLK_EH_RESET_TIMER; | |
594 | ||
595 | return q->mq_ops->timeout(rq); | |
596 | } | |
597 | ||
320ae51f JA |
598 | static void blk_mq_rq_timer(unsigned long data) |
599 | { | |
600 | struct request_queue *q = (struct request_queue *) data; | |
601 | struct blk_mq_hw_ctx *hctx; | |
602 | unsigned long next = 0; | |
603 | int i, next_set = 0; | |
604 | ||
484b4061 JA |
605 | queue_for_each_hw_ctx(q, hctx, i) { |
606 | /* | |
607 | * If not software queues are currently mapped to this | |
608 | * hardware queue, there's nothing to check | |
609 | */ | |
610 | if (!hctx->nr_ctx || !hctx->tags) | |
611 | continue; | |
612 | ||
320ae51f | 613 | blk_mq_hw_ctx_check_timeout(hctx, &next, &next_set); |
484b4061 | 614 | } |
320ae51f | 615 | |
0d2602ca JA |
616 | if (next_set) { |
617 | next = blk_rq_timeout(round_jiffies_up(next)); | |
618 | mod_timer(&q->timeout, next); | |
619 | } else { | |
620 | queue_for_each_hw_ctx(q, hctx, i) | |
621 | blk_mq_tag_idle(hctx); | |
622 | } | |
320ae51f JA |
623 | } |
624 | ||
625 | /* | |
626 | * Reverse check our software queue for entries that we could potentially | |
627 | * merge with. Currently includes a hand-wavy stop count of 8, to not spend | |
628 | * too much time checking for merges. | |
629 | */ | |
630 | static bool blk_mq_attempt_merge(struct request_queue *q, | |
631 | struct blk_mq_ctx *ctx, struct bio *bio) | |
632 | { | |
633 | struct request *rq; | |
634 | int checked = 8; | |
635 | ||
636 | list_for_each_entry_reverse(rq, &ctx->rq_list, queuelist) { | |
637 | int el_ret; | |
638 | ||
639 | if (!checked--) | |
640 | break; | |
641 | ||
642 | if (!blk_rq_merge_ok(rq, bio)) | |
643 | continue; | |
644 | ||
645 | el_ret = blk_try_merge(rq, bio); | |
646 | if (el_ret == ELEVATOR_BACK_MERGE) { | |
647 | if (bio_attempt_back_merge(q, rq, bio)) { | |
648 | ctx->rq_merged++; | |
649 | return true; | |
650 | } | |
651 | break; | |
652 | } else if (el_ret == ELEVATOR_FRONT_MERGE) { | |
653 | if (bio_attempt_front_merge(q, rq, bio)) { | |
654 | ctx->rq_merged++; | |
655 | return true; | |
656 | } | |
657 | break; | |
658 | } | |
659 | } | |
660 | ||
661 | return false; | |
662 | } | |
663 | ||
1429d7c9 JA |
664 | /* |
665 | * Process software queues that have been marked busy, splicing them | |
666 | * to the for-dispatch | |
667 | */ | |
668 | static void flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, struct list_head *list) | |
669 | { | |
670 | struct blk_mq_ctx *ctx; | |
671 | int i; | |
672 | ||
673 | for (i = 0; i < hctx->ctx_map.map_size; i++) { | |
674 | struct blk_align_bitmap *bm = &hctx->ctx_map.map[i]; | |
675 | unsigned int off, bit; | |
676 | ||
677 | if (!bm->word) | |
678 | continue; | |
679 | ||
680 | bit = 0; | |
681 | off = i * hctx->ctx_map.bits_per_word; | |
682 | do { | |
683 | bit = find_next_bit(&bm->word, bm->depth, bit); | |
684 | if (bit >= bm->depth) | |
685 | break; | |
686 | ||
687 | ctx = hctx->ctxs[bit + off]; | |
688 | clear_bit(bit, &bm->word); | |
689 | spin_lock(&ctx->lock); | |
690 | list_splice_tail_init(&ctx->rq_list, list); | |
691 | spin_unlock(&ctx->lock); | |
692 | ||
693 | bit++; | |
694 | } while (1); | |
695 | } | |
696 | } | |
697 | ||
320ae51f JA |
698 | /* |
699 | * Run this hardware queue, pulling any software queues mapped to it in. | |
700 | * Note that this function currently has various problems around ordering | |
701 | * of IO. In particular, we'd like FIFO behaviour on handling existing | |
702 | * items on the hctx->dispatch list. Ignore that for now. | |
703 | */ | |
704 | static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx) | |
705 | { | |
706 | struct request_queue *q = hctx->queue; | |
320ae51f JA |
707 | struct request *rq; |
708 | LIST_HEAD(rq_list); | |
1429d7c9 | 709 | int queued; |
320ae51f | 710 | |
fd1270d5 | 711 | WARN_ON(!cpumask_test_cpu(raw_smp_processor_id(), hctx->cpumask)); |
e4043dcf | 712 | |
5d12f905 | 713 | if (unlikely(test_bit(BLK_MQ_S_STOPPED, &hctx->state))) |
320ae51f JA |
714 | return; |
715 | ||
716 | hctx->run++; | |
717 | ||
718 | /* | |
719 | * Touch any software queue that has pending entries. | |
720 | */ | |
1429d7c9 | 721 | flush_busy_ctxs(hctx, &rq_list); |
320ae51f JA |
722 | |
723 | /* | |
724 | * If we have previous entries on our dispatch list, grab them | |
725 | * and stuff them at the front for more fair dispatch. | |
726 | */ | |
727 | if (!list_empty_careful(&hctx->dispatch)) { | |
728 | spin_lock(&hctx->lock); | |
729 | if (!list_empty(&hctx->dispatch)) | |
730 | list_splice_init(&hctx->dispatch, &rq_list); | |
731 | spin_unlock(&hctx->lock); | |
732 | } | |
733 | ||
320ae51f JA |
734 | /* |
735 | * Now process all the entries, sending them to the driver. | |
736 | */ | |
1429d7c9 | 737 | queued = 0; |
320ae51f JA |
738 | while (!list_empty(&rq_list)) { |
739 | int ret; | |
740 | ||
741 | rq = list_first_entry(&rq_list, struct request, queuelist); | |
742 | list_del_init(&rq->queuelist); | |
320ae51f | 743 | |
49f5baa5 | 744 | blk_mq_start_request(rq, list_empty(&rq_list)); |
320ae51f JA |
745 | |
746 | ret = q->mq_ops->queue_rq(hctx, rq); | |
747 | switch (ret) { | |
748 | case BLK_MQ_RQ_QUEUE_OK: | |
749 | queued++; | |
750 | continue; | |
751 | case BLK_MQ_RQ_QUEUE_BUSY: | |
320ae51f | 752 | list_add(&rq->queuelist, &rq_list); |
ed0791b2 | 753 | __blk_mq_requeue_request(rq); |
320ae51f JA |
754 | break; |
755 | default: | |
756 | pr_err("blk-mq: bad return on queue: %d\n", ret); | |
320ae51f | 757 | case BLK_MQ_RQ_QUEUE_ERROR: |
1e93b8c2 | 758 | rq->errors = -EIO; |
320ae51f JA |
759 | blk_mq_end_io(rq, rq->errors); |
760 | break; | |
761 | } | |
762 | ||
763 | if (ret == BLK_MQ_RQ_QUEUE_BUSY) | |
764 | break; | |
765 | } | |
766 | ||
767 | if (!queued) | |
768 | hctx->dispatched[0]++; | |
769 | else if (queued < (1 << (BLK_MQ_MAX_DISPATCH_ORDER - 1))) | |
770 | hctx->dispatched[ilog2(queued) + 1]++; | |
771 | ||
772 | /* | |
773 | * Any items that need requeuing? Stuff them into hctx->dispatch, | |
774 | * that is where we will continue on next queue run. | |
775 | */ | |
776 | if (!list_empty(&rq_list)) { | |
777 | spin_lock(&hctx->lock); | |
778 | list_splice(&rq_list, &hctx->dispatch); | |
779 | spin_unlock(&hctx->lock); | |
780 | } | |
781 | } | |
782 | ||
506e931f JA |
783 | /* |
784 | * It'd be great if the workqueue API had a way to pass | |
785 | * in a mask and had some smarts for more clever placement. | |
786 | * For now we just round-robin here, switching for every | |
787 | * BLK_MQ_CPU_WORK_BATCH queued items. | |
788 | */ | |
789 | static int blk_mq_hctx_next_cpu(struct blk_mq_hw_ctx *hctx) | |
790 | { | |
791 | int cpu = hctx->next_cpu; | |
792 | ||
793 | if (--hctx->next_cpu_batch <= 0) { | |
794 | int next_cpu; | |
795 | ||
796 | next_cpu = cpumask_next(hctx->next_cpu, hctx->cpumask); | |
797 | if (next_cpu >= nr_cpu_ids) | |
798 | next_cpu = cpumask_first(hctx->cpumask); | |
799 | ||
800 | hctx->next_cpu = next_cpu; | |
801 | hctx->next_cpu_batch = BLK_MQ_CPU_WORK_BATCH; | |
802 | } | |
803 | ||
804 | return cpu; | |
805 | } | |
806 | ||
320ae51f JA |
807 | void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async) |
808 | { | |
5d12f905 | 809 | if (unlikely(test_bit(BLK_MQ_S_STOPPED, &hctx->state))) |
320ae51f JA |
810 | return; |
811 | ||
e4043dcf | 812 | if (!async && cpumask_test_cpu(smp_processor_id(), hctx->cpumask)) |
320ae51f | 813 | __blk_mq_run_hw_queue(hctx); |
e4043dcf | 814 | else if (hctx->queue->nr_hw_queues == 1) |
70f4db63 | 815 | kblockd_schedule_delayed_work(&hctx->run_work, 0); |
e4043dcf JA |
816 | else { |
817 | unsigned int cpu; | |
818 | ||
506e931f | 819 | cpu = blk_mq_hctx_next_cpu(hctx); |
70f4db63 | 820 | kblockd_schedule_delayed_work_on(cpu, &hctx->run_work, 0); |
e4043dcf | 821 | } |
320ae51f JA |
822 | } |
823 | ||
824 | void blk_mq_run_queues(struct request_queue *q, bool async) | |
825 | { | |
826 | struct blk_mq_hw_ctx *hctx; | |
827 | int i; | |
828 | ||
829 | queue_for_each_hw_ctx(q, hctx, i) { | |
830 | if ((!blk_mq_hctx_has_pending(hctx) && | |
831 | list_empty_careful(&hctx->dispatch)) || | |
5d12f905 | 832 | test_bit(BLK_MQ_S_STOPPED, &hctx->state)) |
320ae51f JA |
833 | continue; |
834 | ||
e4043dcf | 835 | preempt_disable(); |
320ae51f | 836 | blk_mq_run_hw_queue(hctx, async); |
e4043dcf | 837 | preempt_enable(); |
320ae51f JA |
838 | } |
839 | } | |
840 | EXPORT_SYMBOL(blk_mq_run_queues); | |
841 | ||
842 | void blk_mq_stop_hw_queue(struct blk_mq_hw_ctx *hctx) | |
843 | { | |
70f4db63 CH |
844 | cancel_delayed_work(&hctx->run_work); |
845 | cancel_delayed_work(&hctx->delay_work); | |
320ae51f JA |
846 | set_bit(BLK_MQ_S_STOPPED, &hctx->state); |
847 | } | |
848 | EXPORT_SYMBOL(blk_mq_stop_hw_queue); | |
849 | ||
280d45f6 CH |
850 | void blk_mq_stop_hw_queues(struct request_queue *q) |
851 | { | |
852 | struct blk_mq_hw_ctx *hctx; | |
853 | int i; | |
854 | ||
855 | queue_for_each_hw_ctx(q, hctx, i) | |
856 | blk_mq_stop_hw_queue(hctx); | |
857 | } | |
858 | EXPORT_SYMBOL(blk_mq_stop_hw_queues); | |
859 | ||
320ae51f JA |
860 | void blk_mq_start_hw_queue(struct blk_mq_hw_ctx *hctx) |
861 | { | |
862 | clear_bit(BLK_MQ_S_STOPPED, &hctx->state); | |
e4043dcf JA |
863 | |
864 | preempt_disable(); | |
0ffbce80 | 865 | blk_mq_run_hw_queue(hctx, false); |
e4043dcf | 866 | preempt_enable(); |
320ae51f JA |
867 | } |
868 | EXPORT_SYMBOL(blk_mq_start_hw_queue); | |
869 | ||
2f268556 CH |
870 | void blk_mq_start_hw_queues(struct request_queue *q) |
871 | { | |
872 | struct blk_mq_hw_ctx *hctx; | |
873 | int i; | |
874 | ||
875 | queue_for_each_hw_ctx(q, hctx, i) | |
876 | blk_mq_start_hw_queue(hctx); | |
877 | } | |
878 | EXPORT_SYMBOL(blk_mq_start_hw_queues); | |
879 | ||
880 | ||
1b4a3258 | 881 | void blk_mq_start_stopped_hw_queues(struct request_queue *q, bool async) |
320ae51f JA |
882 | { |
883 | struct blk_mq_hw_ctx *hctx; | |
884 | int i; | |
885 | ||
886 | queue_for_each_hw_ctx(q, hctx, i) { | |
887 | if (!test_bit(BLK_MQ_S_STOPPED, &hctx->state)) | |
888 | continue; | |
889 | ||
890 | clear_bit(BLK_MQ_S_STOPPED, &hctx->state); | |
e4043dcf | 891 | preempt_disable(); |
1b4a3258 | 892 | blk_mq_run_hw_queue(hctx, async); |
e4043dcf | 893 | preempt_enable(); |
320ae51f JA |
894 | } |
895 | } | |
896 | EXPORT_SYMBOL(blk_mq_start_stopped_hw_queues); | |
897 | ||
70f4db63 | 898 | static void blk_mq_run_work_fn(struct work_struct *work) |
320ae51f JA |
899 | { |
900 | struct blk_mq_hw_ctx *hctx; | |
901 | ||
70f4db63 | 902 | hctx = container_of(work, struct blk_mq_hw_ctx, run_work.work); |
e4043dcf | 903 | |
320ae51f JA |
904 | __blk_mq_run_hw_queue(hctx); |
905 | } | |
906 | ||
70f4db63 CH |
907 | static void blk_mq_delay_work_fn(struct work_struct *work) |
908 | { | |
909 | struct blk_mq_hw_ctx *hctx; | |
910 | ||
911 | hctx = container_of(work, struct blk_mq_hw_ctx, delay_work.work); | |
912 | ||
913 | if (test_and_clear_bit(BLK_MQ_S_STOPPED, &hctx->state)) | |
914 | __blk_mq_run_hw_queue(hctx); | |
915 | } | |
916 | ||
917 | void blk_mq_delay_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs) | |
918 | { | |
919 | unsigned long tmo = msecs_to_jiffies(msecs); | |
920 | ||
921 | if (hctx->queue->nr_hw_queues == 1) | |
922 | kblockd_schedule_delayed_work(&hctx->delay_work, tmo); | |
923 | else { | |
924 | unsigned int cpu; | |
925 | ||
506e931f | 926 | cpu = blk_mq_hctx_next_cpu(hctx); |
70f4db63 CH |
927 | kblockd_schedule_delayed_work_on(cpu, &hctx->delay_work, tmo); |
928 | } | |
929 | } | |
930 | EXPORT_SYMBOL(blk_mq_delay_queue); | |
931 | ||
320ae51f | 932 | static void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, |
72a0a36e | 933 | struct request *rq, bool at_head) |
320ae51f JA |
934 | { |
935 | struct blk_mq_ctx *ctx = rq->mq_ctx; | |
936 | ||
01b983c9 JA |
937 | trace_block_rq_insert(hctx->queue, rq); |
938 | ||
72a0a36e CH |
939 | if (at_head) |
940 | list_add(&rq->queuelist, &ctx->rq_list); | |
941 | else | |
942 | list_add_tail(&rq->queuelist, &ctx->rq_list); | |
4bb659b1 | 943 | |
320ae51f | 944 | blk_mq_hctx_mark_pending(hctx, ctx); |
320ae51f JA |
945 | } |
946 | ||
eeabc850 CH |
947 | void blk_mq_insert_request(struct request *rq, bool at_head, bool run_queue, |
948 | bool async) | |
320ae51f | 949 | { |
eeabc850 | 950 | struct request_queue *q = rq->q; |
320ae51f | 951 | struct blk_mq_hw_ctx *hctx; |
eeabc850 CH |
952 | struct blk_mq_ctx *ctx = rq->mq_ctx, *current_ctx; |
953 | ||
954 | current_ctx = blk_mq_get_ctx(q); | |
955 | if (!cpu_online(ctx->cpu)) | |
956 | rq->mq_ctx = ctx = current_ctx; | |
320ae51f | 957 | |
320ae51f JA |
958 | hctx = q->mq_ops->map_queue(q, ctx->cpu); |
959 | ||
eeabc850 CH |
960 | if (rq->cmd_flags & (REQ_FLUSH | REQ_FUA) && |
961 | !(rq->cmd_flags & (REQ_FLUSH_SEQ))) { | |
320ae51f JA |
962 | blk_insert_flush(rq); |
963 | } else { | |
320ae51f | 964 | spin_lock(&ctx->lock); |
72a0a36e | 965 | __blk_mq_insert_request(hctx, rq, at_head); |
320ae51f | 966 | spin_unlock(&ctx->lock); |
320ae51f JA |
967 | } |
968 | ||
320ae51f JA |
969 | if (run_queue) |
970 | blk_mq_run_hw_queue(hctx, async); | |
e4043dcf JA |
971 | |
972 | blk_mq_put_ctx(current_ctx); | |
320ae51f JA |
973 | } |
974 | ||
975 | static void blk_mq_insert_requests(struct request_queue *q, | |
976 | struct blk_mq_ctx *ctx, | |
977 | struct list_head *list, | |
978 | int depth, | |
979 | bool from_schedule) | |
980 | ||
981 | { | |
982 | struct blk_mq_hw_ctx *hctx; | |
983 | struct blk_mq_ctx *current_ctx; | |
984 | ||
985 | trace_block_unplug(q, depth, !from_schedule); | |
986 | ||
987 | current_ctx = blk_mq_get_ctx(q); | |
988 | ||
989 | if (!cpu_online(ctx->cpu)) | |
990 | ctx = current_ctx; | |
991 | hctx = q->mq_ops->map_queue(q, ctx->cpu); | |
992 | ||
993 | /* | |
994 | * preemption doesn't flush plug list, so it's possible ctx->cpu is | |
995 | * offline now | |
996 | */ | |
997 | spin_lock(&ctx->lock); | |
998 | while (!list_empty(list)) { | |
999 | struct request *rq; | |
1000 | ||
1001 | rq = list_first_entry(list, struct request, queuelist); | |
1002 | list_del_init(&rq->queuelist); | |
1003 | rq->mq_ctx = ctx; | |
72a0a36e | 1004 | __blk_mq_insert_request(hctx, rq, false); |
320ae51f JA |
1005 | } |
1006 | spin_unlock(&ctx->lock); | |
1007 | ||
320ae51f | 1008 | blk_mq_run_hw_queue(hctx, from_schedule); |
e4043dcf | 1009 | blk_mq_put_ctx(current_ctx); |
320ae51f JA |
1010 | } |
1011 | ||
1012 | static int plug_ctx_cmp(void *priv, struct list_head *a, struct list_head *b) | |
1013 | { | |
1014 | struct request *rqa = container_of(a, struct request, queuelist); | |
1015 | struct request *rqb = container_of(b, struct request, queuelist); | |
1016 | ||
1017 | return !(rqa->mq_ctx < rqb->mq_ctx || | |
1018 | (rqa->mq_ctx == rqb->mq_ctx && | |
1019 | blk_rq_pos(rqa) < blk_rq_pos(rqb))); | |
1020 | } | |
1021 | ||
1022 | void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule) | |
1023 | { | |
1024 | struct blk_mq_ctx *this_ctx; | |
1025 | struct request_queue *this_q; | |
1026 | struct request *rq; | |
1027 | LIST_HEAD(list); | |
1028 | LIST_HEAD(ctx_list); | |
1029 | unsigned int depth; | |
1030 | ||
1031 | list_splice_init(&plug->mq_list, &list); | |
1032 | ||
1033 | list_sort(NULL, &list, plug_ctx_cmp); | |
1034 | ||
1035 | this_q = NULL; | |
1036 | this_ctx = NULL; | |
1037 | depth = 0; | |
1038 | ||
1039 | while (!list_empty(&list)) { | |
1040 | rq = list_entry_rq(list.next); | |
1041 | list_del_init(&rq->queuelist); | |
1042 | BUG_ON(!rq->q); | |
1043 | if (rq->mq_ctx != this_ctx) { | |
1044 | if (this_ctx) { | |
1045 | blk_mq_insert_requests(this_q, this_ctx, | |
1046 | &ctx_list, depth, | |
1047 | from_schedule); | |
1048 | } | |
1049 | ||
1050 | this_ctx = rq->mq_ctx; | |
1051 | this_q = rq->q; | |
1052 | depth = 0; | |
1053 | } | |
1054 | ||
1055 | depth++; | |
1056 | list_add_tail(&rq->queuelist, &ctx_list); | |
1057 | } | |
1058 | ||
1059 | /* | |
1060 | * If 'this_ctx' is set, we know we have entries to complete | |
1061 | * on 'ctx_list'. Do those. | |
1062 | */ | |
1063 | if (this_ctx) { | |
1064 | blk_mq_insert_requests(this_q, this_ctx, &ctx_list, depth, | |
1065 | from_schedule); | |
1066 | } | |
1067 | } | |
1068 | ||
1069 | static void blk_mq_bio_to_request(struct request *rq, struct bio *bio) | |
1070 | { | |
1071 | init_request_from_bio(rq, bio); | |
4b570521 | 1072 | |
3ee32372 | 1073 | if (blk_do_io_stat(rq)) |
4b570521 | 1074 | blk_account_io_start(rq, 1); |
320ae51f JA |
1075 | } |
1076 | ||
274a5843 JA |
1077 | static inline bool hctx_allow_merges(struct blk_mq_hw_ctx *hctx) |
1078 | { | |
1079 | return (hctx->flags & BLK_MQ_F_SHOULD_MERGE) && | |
1080 | !blk_queue_nomerges(hctx->queue); | |
1081 | } | |
1082 | ||
07068d5b JA |
1083 | static inline bool blk_mq_merge_queue_io(struct blk_mq_hw_ctx *hctx, |
1084 | struct blk_mq_ctx *ctx, | |
1085 | struct request *rq, struct bio *bio) | |
320ae51f | 1086 | { |
274a5843 | 1087 | if (!hctx_allow_merges(hctx)) { |
07068d5b JA |
1088 | blk_mq_bio_to_request(rq, bio); |
1089 | spin_lock(&ctx->lock); | |
1090 | insert_rq: | |
1091 | __blk_mq_insert_request(hctx, rq, false); | |
1092 | spin_unlock(&ctx->lock); | |
1093 | return false; | |
1094 | } else { | |
274a5843 JA |
1095 | struct request_queue *q = hctx->queue; |
1096 | ||
07068d5b JA |
1097 | spin_lock(&ctx->lock); |
1098 | if (!blk_mq_attempt_merge(q, ctx, bio)) { | |
1099 | blk_mq_bio_to_request(rq, bio); | |
1100 | goto insert_rq; | |
1101 | } | |
320ae51f | 1102 | |
07068d5b JA |
1103 | spin_unlock(&ctx->lock); |
1104 | __blk_mq_free_request(hctx, ctx, rq); | |
1105 | return true; | |
14ec77f3 | 1106 | } |
07068d5b | 1107 | } |
14ec77f3 | 1108 | |
07068d5b JA |
1109 | struct blk_map_ctx { |
1110 | struct blk_mq_hw_ctx *hctx; | |
1111 | struct blk_mq_ctx *ctx; | |
1112 | }; | |
1113 | ||
1114 | static struct request *blk_mq_map_request(struct request_queue *q, | |
1115 | struct bio *bio, | |
1116 | struct blk_map_ctx *data) | |
1117 | { | |
1118 | struct blk_mq_hw_ctx *hctx; | |
1119 | struct blk_mq_ctx *ctx; | |
1120 | struct request *rq; | |
1121 | int rw = bio_data_dir(bio); | |
cb96a42c | 1122 | struct blk_mq_alloc_data alloc_data; |
320ae51f | 1123 | |
07068d5b | 1124 | if (unlikely(blk_mq_queue_enter(q))) { |
320ae51f | 1125 | bio_endio(bio, -EIO); |
07068d5b | 1126 | return NULL; |
320ae51f JA |
1127 | } |
1128 | ||
1129 | ctx = blk_mq_get_ctx(q); | |
1130 | hctx = q->mq_ops->map_queue(q, ctx->cpu); | |
1131 | ||
07068d5b | 1132 | if (rw_is_sync(bio->bi_rw)) |
27fbf4e8 | 1133 | rw |= REQ_SYNC; |
07068d5b | 1134 | |
320ae51f | 1135 | trace_block_getrq(q, bio, rw); |
cb96a42c ML |
1136 | blk_mq_set_alloc_data(&alloc_data, q, GFP_ATOMIC, false, ctx, |
1137 | hctx); | |
1138 | rq = __blk_mq_alloc_request(&alloc_data, rw); | |
5dee8577 | 1139 | if (unlikely(!rq)) { |
793597a6 | 1140 | __blk_mq_run_hw_queue(hctx); |
320ae51f JA |
1141 | blk_mq_put_ctx(ctx); |
1142 | trace_block_sleeprq(q, bio, rw); | |
793597a6 CH |
1143 | |
1144 | ctx = blk_mq_get_ctx(q); | |
320ae51f | 1145 | hctx = q->mq_ops->map_queue(q, ctx->cpu); |
cb96a42c ML |
1146 | blk_mq_set_alloc_data(&alloc_data, q, |
1147 | __GFP_WAIT|GFP_ATOMIC, false, ctx, hctx); | |
1148 | rq = __blk_mq_alloc_request(&alloc_data, rw); | |
1149 | ctx = alloc_data.ctx; | |
1150 | hctx = alloc_data.hctx; | |
320ae51f JA |
1151 | } |
1152 | ||
1153 | hctx->queued++; | |
07068d5b JA |
1154 | data->hctx = hctx; |
1155 | data->ctx = ctx; | |
1156 | return rq; | |
1157 | } | |
1158 | ||
1159 | /* | |
1160 | * Multiple hardware queue variant. This will not use per-process plugs, | |
1161 | * but will attempt to bypass the hctx queueing if we can go straight to | |
1162 | * hardware for SYNC IO. | |
1163 | */ | |
1164 | static void blk_mq_make_request(struct request_queue *q, struct bio *bio) | |
1165 | { | |
1166 | const int is_sync = rw_is_sync(bio->bi_rw); | |
1167 | const int is_flush_fua = bio->bi_rw & (REQ_FLUSH | REQ_FUA); | |
1168 | struct blk_map_ctx data; | |
1169 | struct request *rq; | |
1170 | ||
1171 | blk_queue_bounce(q, &bio); | |
1172 | ||
1173 | if (bio_integrity_enabled(bio) && bio_integrity_prep(bio)) { | |
1174 | bio_endio(bio, -EIO); | |
1175 | return; | |
1176 | } | |
1177 | ||
1178 | rq = blk_mq_map_request(q, bio, &data); | |
1179 | if (unlikely(!rq)) | |
1180 | return; | |
1181 | ||
1182 | if (unlikely(is_flush_fua)) { | |
1183 | blk_mq_bio_to_request(rq, bio); | |
1184 | blk_insert_flush(rq); | |
1185 | goto run_queue; | |
1186 | } | |
1187 | ||
1188 | if (is_sync) { | |
1189 | int ret; | |
1190 | ||
1191 | blk_mq_bio_to_request(rq, bio); | |
1192 | blk_mq_start_request(rq, true); | |
1193 | ||
1194 | /* | |
1195 | * For OK queue, we are done. For error, kill it. Any other | |
1196 | * error (busy), just add it to our list as we previously | |
1197 | * would have done | |
1198 | */ | |
1199 | ret = q->mq_ops->queue_rq(data.hctx, rq); | |
1200 | if (ret == BLK_MQ_RQ_QUEUE_OK) | |
1201 | goto done; | |
1202 | else { | |
1203 | __blk_mq_requeue_request(rq); | |
1204 | ||
1205 | if (ret == BLK_MQ_RQ_QUEUE_ERROR) { | |
1206 | rq->errors = -EIO; | |
1207 | blk_mq_end_io(rq, rq->errors); | |
1208 | goto done; | |
1209 | } | |
1210 | } | |
1211 | } | |
1212 | ||
1213 | if (!blk_mq_merge_queue_io(data.hctx, data.ctx, rq, bio)) { | |
1214 | /* | |
1215 | * For a SYNC request, send it to the hardware immediately. For | |
1216 | * an ASYNC request, just ensure that we run it later on. The | |
1217 | * latter allows for merging opportunities and more efficient | |
1218 | * dispatching. | |
1219 | */ | |
1220 | run_queue: | |
1221 | blk_mq_run_hw_queue(data.hctx, !is_sync || is_flush_fua); | |
1222 | } | |
1223 | done: | |
1224 | blk_mq_put_ctx(data.ctx); | |
1225 | } | |
1226 | ||
1227 | /* | |
1228 | * Single hardware queue variant. This will attempt to use any per-process | |
1229 | * plug for merging and IO deferral. | |
1230 | */ | |
1231 | static void blk_sq_make_request(struct request_queue *q, struct bio *bio) | |
1232 | { | |
1233 | const int is_sync = rw_is_sync(bio->bi_rw); | |
1234 | const int is_flush_fua = bio->bi_rw & (REQ_FLUSH | REQ_FUA); | |
1235 | unsigned int use_plug, request_count = 0; | |
1236 | struct blk_map_ctx data; | |
1237 | struct request *rq; | |
1238 | ||
1239 | /* | |
1240 | * If we have multiple hardware queues, just go directly to | |
1241 | * one of those for sync IO. | |
1242 | */ | |
1243 | use_plug = !is_flush_fua && !is_sync; | |
1244 | ||
1245 | blk_queue_bounce(q, &bio); | |
1246 | ||
1247 | if (bio_integrity_enabled(bio) && bio_integrity_prep(bio)) { | |
1248 | bio_endio(bio, -EIO); | |
1249 | return; | |
1250 | } | |
1251 | ||
1252 | if (use_plug && !blk_queue_nomerges(q) && | |
1253 | blk_attempt_plug_merge(q, bio, &request_count)) | |
1254 | return; | |
1255 | ||
1256 | rq = blk_mq_map_request(q, bio, &data); | |
ff87bcec JA |
1257 | if (unlikely(!rq)) |
1258 | return; | |
320ae51f JA |
1259 | |
1260 | if (unlikely(is_flush_fua)) { | |
1261 | blk_mq_bio_to_request(rq, bio); | |
320ae51f JA |
1262 | blk_insert_flush(rq); |
1263 | goto run_queue; | |
1264 | } | |
1265 | ||
1266 | /* | |
1267 | * A task plug currently exists. Since this is completely lockless, | |
1268 | * utilize that to temporarily store requests until the task is | |
1269 | * either done or scheduled away. | |
1270 | */ | |
1271 | if (use_plug) { | |
1272 | struct blk_plug *plug = current->plug; | |
1273 | ||
1274 | if (plug) { | |
1275 | blk_mq_bio_to_request(rq, bio); | |
92f399c7 | 1276 | if (list_empty(&plug->mq_list)) |
320ae51f JA |
1277 | trace_block_plug(q); |
1278 | else if (request_count >= BLK_MAX_REQUEST_COUNT) { | |
1279 | blk_flush_plug_list(plug, false); | |
1280 | trace_block_plug(q); | |
1281 | } | |
1282 | list_add_tail(&rq->queuelist, &plug->mq_list); | |
07068d5b | 1283 | blk_mq_put_ctx(data.ctx); |
320ae51f JA |
1284 | return; |
1285 | } | |
1286 | } | |
1287 | ||
07068d5b JA |
1288 | if (!blk_mq_merge_queue_io(data.hctx, data.ctx, rq, bio)) { |
1289 | /* | |
1290 | * For a SYNC request, send it to the hardware immediately. For | |
1291 | * an ASYNC request, just ensure that we run it later on. The | |
1292 | * latter allows for merging opportunities and more efficient | |
1293 | * dispatching. | |
1294 | */ | |
1295 | run_queue: | |
1296 | blk_mq_run_hw_queue(data.hctx, !is_sync || is_flush_fua); | |
320ae51f JA |
1297 | } |
1298 | ||
07068d5b | 1299 | blk_mq_put_ctx(data.ctx); |
320ae51f JA |
1300 | } |
1301 | ||
1302 | /* | |
1303 | * Default mapping to a software queue, since we use one per CPU. | |
1304 | */ | |
1305 | struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q, const int cpu) | |
1306 | { | |
1307 | return q->queue_hw_ctx[q->mq_map[cpu]]; | |
1308 | } | |
1309 | EXPORT_SYMBOL(blk_mq_map_queue); | |
1310 | ||
24d2f903 CH |
1311 | static void blk_mq_free_rq_map(struct blk_mq_tag_set *set, |
1312 | struct blk_mq_tags *tags, unsigned int hctx_idx) | |
95363efd | 1313 | { |
e9b267d9 | 1314 | struct page *page; |
320ae51f | 1315 | |
24d2f903 | 1316 | if (tags->rqs && set->ops->exit_request) { |
e9b267d9 | 1317 | int i; |
320ae51f | 1318 | |
24d2f903 CH |
1319 | for (i = 0; i < tags->nr_tags; i++) { |
1320 | if (!tags->rqs[i]) | |
e9b267d9 | 1321 | continue; |
24d2f903 CH |
1322 | set->ops->exit_request(set->driver_data, tags->rqs[i], |
1323 | hctx_idx, i); | |
e9b267d9 | 1324 | } |
320ae51f | 1325 | } |
320ae51f | 1326 | |
24d2f903 CH |
1327 | while (!list_empty(&tags->page_list)) { |
1328 | page = list_first_entry(&tags->page_list, struct page, lru); | |
6753471c | 1329 | list_del_init(&page->lru); |
320ae51f JA |
1330 | __free_pages(page, page->private); |
1331 | } | |
1332 | ||
24d2f903 | 1333 | kfree(tags->rqs); |
320ae51f | 1334 | |
24d2f903 | 1335 | blk_mq_free_tags(tags); |
320ae51f JA |
1336 | } |
1337 | ||
1338 | static size_t order_to_size(unsigned int order) | |
1339 | { | |
4ca08500 | 1340 | return (size_t)PAGE_SIZE << order; |
320ae51f JA |
1341 | } |
1342 | ||
24d2f903 CH |
1343 | static struct blk_mq_tags *blk_mq_init_rq_map(struct blk_mq_tag_set *set, |
1344 | unsigned int hctx_idx) | |
320ae51f | 1345 | { |
24d2f903 | 1346 | struct blk_mq_tags *tags; |
320ae51f JA |
1347 | unsigned int i, j, entries_per_page, max_order = 4; |
1348 | size_t rq_size, left; | |
1349 | ||
24d2f903 CH |
1350 | tags = blk_mq_init_tags(set->queue_depth, set->reserved_tags, |
1351 | set->numa_node); | |
1352 | if (!tags) | |
1353 | return NULL; | |
320ae51f | 1354 | |
24d2f903 CH |
1355 | INIT_LIST_HEAD(&tags->page_list); |
1356 | ||
1357 | tags->rqs = kmalloc_node(set->queue_depth * sizeof(struct request *), | |
1358 | GFP_KERNEL, set->numa_node); | |
1359 | if (!tags->rqs) { | |
1360 | blk_mq_free_tags(tags); | |
1361 | return NULL; | |
1362 | } | |
320ae51f JA |
1363 | |
1364 | /* | |
1365 | * rq_size is the size of the request plus driver payload, rounded | |
1366 | * to the cacheline size | |
1367 | */ | |
24d2f903 | 1368 | rq_size = round_up(sizeof(struct request) + set->cmd_size, |
320ae51f | 1369 | cache_line_size()); |
24d2f903 | 1370 | left = rq_size * set->queue_depth; |
320ae51f | 1371 | |
24d2f903 | 1372 | for (i = 0; i < set->queue_depth; ) { |
320ae51f JA |
1373 | int this_order = max_order; |
1374 | struct page *page; | |
1375 | int to_do; | |
1376 | void *p; | |
1377 | ||
1378 | while (left < order_to_size(this_order - 1) && this_order) | |
1379 | this_order--; | |
1380 | ||
1381 | do { | |
24d2f903 CH |
1382 | page = alloc_pages_node(set->numa_node, GFP_KERNEL, |
1383 | this_order); | |
320ae51f JA |
1384 | if (page) |
1385 | break; | |
1386 | if (!this_order--) | |
1387 | break; | |
1388 | if (order_to_size(this_order) < rq_size) | |
1389 | break; | |
1390 | } while (1); | |
1391 | ||
1392 | if (!page) | |
24d2f903 | 1393 | goto fail; |
320ae51f JA |
1394 | |
1395 | page->private = this_order; | |
24d2f903 | 1396 | list_add_tail(&page->lru, &tags->page_list); |
320ae51f JA |
1397 | |
1398 | p = page_address(page); | |
1399 | entries_per_page = order_to_size(this_order) / rq_size; | |
24d2f903 | 1400 | to_do = min(entries_per_page, set->queue_depth - i); |
320ae51f JA |
1401 | left -= to_do * rq_size; |
1402 | for (j = 0; j < to_do; j++) { | |
24d2f903 CH |
1403 | tags->rqs[i] = p; |
1404 | if (set->ops->init_request) { | |
1405 | if (set->ops->init_request(set->driver_data, | |
1406 | tags->rqs[i], hctx_idx, i, | |
1407 | set->numa_node)) | |
1408 | goto fail; | |
e9b267d9 CH |
1409 | } |
1410 | ||
320ae51f JA |
1411 | p += rq_size; |
1412 | i++; | |
1413 | } | |
1414 | } | |
1415 | ||
24d2f903 | 1416 | return tags; |
320ae51f | 1417 | |
24d2f903 CH |
1418 | fail: |
1419 | pr_warn("%s: failed to allocate requests\n", __func__); | |
1420 | blk_mq_free_rq_map(set, tags, hctx_idx); | |
1421 | return NULL; | |
320ae51f JA |
1422 | } |
1423 | ||
1429d7c9 JA |
1424 | static void blk_mq_free_bitmap(struct blk_mq_ctxmap *bitmap) |
1425 | { | |
1426 | kfree(bitmap->map); | |
1427 | } | |
1428 | ||
1429 | static int blk_mq_alloc_bitmap(struct blk_mq_ctxmap *bitmap, int node) | |
1430 | { | |
1431 | unsigned int bpw = 8, total, num_maps, i; | |
1432 | ||
1433 | bitmap->bits_per_word = bpw; | |
1434 | ||
1435 | num_maps = ALIGN(nr_cpu_ids, bpw) / bpw; | |
1436 | bitmap->map = kzalloc_node(num_maps * sizeof(struct blk_align_bitmap), | |
1437 | GFP_KERNEL, node); | |
1438 | if (!bitmap->map) | |
1439 | return -ENOMEM; | |
1440 | ||
1441 | bitmap->map_size = num_maps; | |
1442 | ||
1443 | total = nr_cpu_ids; | |
1444 | for (i = 0; i < num_maps; i++) { | |
1445 | bitmap->map[i].depth = min(total, bitmap->bits_per_word); | |
1446 | total -= bitmap->map[i].depth; | |
1447 | } | |
1448 | ||
1449 | return 0; | |
1450 | } | |
1451 | ||
484b4061 JA |
1452 | static int blk_mq_hctx_cpu_offline(struct blk_mq_hw_ctx *hctx, int cpu) |
1453 | { | |
1454 | struct request_queue *q = hctx->queue; | |
1455 | struct blk_mq_ctx *ctx; | |
1456 | LIST_HEAD(tmp); | |
1457 | ||
1458 | /* | |
1459 | * Move ctx entries to new CPU, if this one is going away. | |
1460 | */ | |
1461 | ctx = __blk_mq_get_ctx(q, cpu); | |
1462 | ||
1463 | spin_lock(&ctx->lock); | |
1464 | if (!list_empty(&ctx->rq_list)) { | |
1465 | list_splice_init(&ctx->rq_list, &tmp); | |
1466 | blk_mq_hctx_clear_pending(hctx, ctx); | |
1467 | } | |
1468 | spin_unlock(&ctx->lock); | |
1469 | ||
1470 | if (list_empty(&tmp)) | |
1471 | return NOTIFY_OK; | |
1472 | ||
1473 | ctx = blk_mq_get_ctx(q); | |
1474 | spin_lock(&ctx->lock); | |
1475 | ||
1476 | while (!list_empty(&tmp)) { | |
1477 | struct request *rq; | |
1478 | ||
1479 | rq = list_first_entry(&tmp, struct request, queuelist); | |
1480 | rq->mq_ctx = ctx; | |
1481 | list_move_tail(&rq->queuelist, &ctx->rq_list); | |
1482 | } | |
1483 | ||
1484 | hctx = q->mq_ops->map_queue(q, ctx->cpu); | |
1485 | blk_mq_hctx_mark_pending(hctx, ctx); | |
1486 | ||
1487 | spin_unlock(&ctx->lock); | |
1488 | ||
1489 | blk_mq_run_hw_queue(hctx, true); | |
1490 | blk_mq_put_ctx(ctx); | |
1491 | return NOTIFY_OK; | |
1492 | } | |
1493 | ||
1494 | static int blk_mq_hctx_cpu_online(struct blk_mq_hw_ctx *hctx, int cpu) | |
1495 | { | |
1496 | struct request_queue *q = hctx->queue; | |
1497 | struct blk_mq_tag_set *set = q->tag_set; | |
1498 | ||
1499 | if (set->tags[hctx->queue_num]) | |
1500 | return NOTIFY_OK; | |
1501 | ||
1502 | set->tags[hctx->queue_num] = blk_mq_init_rq_map(set, hctx->queue_num); | |
1503 | if (!set->tags[hctx->queue_num]) | |
1504 | return NOTIFY_STOP; | |
1505 | ||
1506 | hctx->tags = set->tags[hctx->queue_num]; | |
1507 | return NOTIFY_OK; | |
1508 | } | |
1509 | ||
1510 | static int blk_mq_hctx_notify(void *data, unsigned long action, | |
1511 | unsigned int cpu) | |
1512 | { | |
1513 | struct blk_mq_hw_ctx *hctx = data; | |
1514 | ||
1515 | if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) | |
1516 | return blk_mq_hctx_cpu_offline(hctx, cpu); | |
1517 | else if (action == CPU_ONLINE || action == CPU_ONLINE_FROZEN) | |
1518 | return blk_mq_hctx_cpu_online(hctx, cpu); | |
1519 | ||
1520 | return NOTIFY_OK; | |
1521 | } | |
1522 | ||
624dbe47 ML |
1523 | static void blk_mq_exit_hw_queues(struct request_queue *q, |
1524 | struct blk_mq_tag_set *set, int nr_queue) | |
1525 | { | |
1526 | struct blk_mq_hw_ctx *hctx; | |
1527 | unsigned int i; | |
1528 | ||
1529 | queue_for_each_hw_ctx(q, hctx, i) { | |
1530 | if (i == nr_queue) | |
1531 | break; | |
1532 | ||
f899fed4 JA |
1533 | blk_mq_tag_idle(hctx); |
1534 | ||
624dbe47 ML |
1535 | if (set->ops->exit_hctx) |
1536 | set->ops->exit_hctx(hctx, i); | |
1537 | ||
1538 | blk_mq_unregister_cpu_notifier(&hctx->cpu_notifier); | |
1539 | kfree(hctx->ctxs); | |
1540 | blk_mq_free_bitmap(&hctx->ctx_map); | |
1541 | } | |
1542 | ||
1543 | } | |
1544 | ||
1545 | static void blk_mq_free_hw_queues(struct request_queue *q, | |
1546 | struct blk_mq_tag_set *set) | |
1547 | { | |
1548 | struct blk_mq_hw_ctx *hctx; | |
1549 | unsigned int i; | |
1550 | ||
1551 | queue_for_each_hw_ctx(q, hctx, i) { | |
1552 | free_cpumask_var(hctx->cpumask); | |
cdef54dd | 1553 | kfree(hctx); |
624dbe47 ML |
1554 | } |
1555 | } | |
1556 | ||
320ae51f | 1557 | static int blk_mq_init_hw_queues(struct request_queue *q, |
24d2f903 | 1558 | struct blk_mq_tag_set *set) |
320ae51f JA |
1559 | { |
1560 | struct blk_mq_hw_ctx *hctx; | |
624dbe47 | 1561 | unsigned int i; |
320ae51f JA |
1562 | |
1563 | /* | |
1564 | * Initialize hardware queues | |
1565 | */ | |
1566 | queue_for_each_hw_ctx(q, hctx, i) { | |
320ae51f JA |
1567 | int node; |
1568 | ||
1569 | node = hctx->numa_node; | |
1570 | if (node == NUMA_NO_NODE) | |
24d2f903 | 1571 | node = hctx->numa_node = set->numa_node; |
320ae51f | 1572 | |
70f4db63 CH |
1573 | INIT_DELAYED_WORK(&hctx->run_work, blk_mq_run_work_fn); |
1574 | INIT_DELAYED_WORK(&hctx->delay_work, blk_mq_delay_work_fn); | |
320ae51f JA |
1575 | spin_lock_init(&hctx->lock); |
1576 | INIT_LIST_HEAD(&hctx->dispatch); | |
1577 | hctx->queue = q; | |
1578 | hctx->queue_num = i; | |
24d2f903 CH |
1579 | hctx->flags = set->flags; |
1580 | hctx->cmd_size = set->cmd_size; | |
320ae51f JA |
1581 | |
1582 | blk_mq_init_cpu_notifier(&hctx->cpu_notifier, | |
1583 | blk_mq_hctx_notify, hctx); | |
1584 | blk_mq_register_cpu_notifier(&hctx->cpu_notifier); | |
1585 | ||
24d2f903 | 1586 | hctx->tags = set->tags[i]; |
320ae51f JA |
1587 | |
1588 | /* | |
a68aafa5 | 1589 | * Allocate space for all possible cpus to avoid allocation at |
320ae51f JA |
1590 | * runtime |
1591 | */ | |
1592 | hctx->ctxs = kmalloc_node(nr_cpu_ids * sizeof(void *), | |
1593 | GFP_KERNEL, node); | |
1594 | if (!hctx->ctxs) | |
1595 | break; | |
1596 | ||
1429d7c9 | 1597 | if (blk_mq_alloc_bitmap(&hctx->ctx_map, node)) |
320ae51f JA |
1598 | break; |
1599 | ||
320ae51f JA |
1600 | hctx->nr_ctx = 0; |
1601 | ||
24d2f903 CH |
1602 | if (set->ops->init_hctx && |
1603 | set->ops->init_hctx(hctx, set->driver_data, i)) | |
320ae51f JA |
1604 | break; |
1605 | } | |
1606 | ||
1607 | if (i == q->nr_hw_queues) | |
1608 | return 0; | |
1609 | ||
1610 | /* | |
1611 | * Init failed | |
1612 | */ | |
624dbe47 | 1613 | blk_mq_exit_hw_queues(q, set, i); |
320ae51f JA |
1614 | |
1615 | return 1; | |
1616 | } | |
1617 | ||
1618 | static void blk_mq_init_cpu_queues(struct request_queue *q, | |
1619 | unsigned int nr_hw_queues) | |
1620 | { | |
1621 | unsigned int i; | |
1622 | ||
1623 | for_each_possible_cpu(i) { | |
1624 | struct blk_mq_ctx *__ctx = per_cpu_ptr(q->queue_ctx, i); | |
1625 | struct blk_mq_hw_ctx *hctx; | |
1626 | ||
1627 | memset(__ctx, 0, sizeof(*__ctx)); | |
1628 | __ctx->cpu = i; | |
1629 | spin_lock_init(&__ctx->lock); | |
1630 | INIT_LIST_HEAD(&__ctx->rq_list); | |
1631 | __ctx->queue = q; | |
1632 | ||
1633 | /* If the cpu isn't online, the cpu is mapped to first hctx */ | |
320ae51f JA |
1634 | if (!cpu_online(i)) |
1635 | continue; | |
1636 | ||
e4043dcf JA |
1637 | hctx = q->mq_ops->map_queue(q, i); |
1638 | cpumask_set_cpu(i, hctx->cpumask); | |
1639 | hctx->nr_ctx++; | |
1640 | ||
320ae51f JA |
1641 | /* |
1642 | * Set local node, IFF we have more than one hw queue. If | |
1643 | * not, we remain on the home node of the device | |
1644 | */ | |
1645 | if (nr_hw_queues > 1 && hctx->numa_node == NUMA_NO_NODE) | |
1646 | hctx->numa_node = cpu_to_node(i); | |
1647 | } | |
1648 | } | |
1649 | ||
1650 | static void blk_mq_map_swqueue(struct request_queue *q) | |
1651 | { | |
1652 | unsigned int i; | |
1653 | struct blk_mq_hw_ctx *hctx; | |
1654 | struct blk_mq_ctx *ctx; | |
1655 | ||
1656 | queue_for_each_hw_ctx(q, hctx, i) { | |
e4043dcf | 1657 | cpumask_clear(hctx->cpumask); |
320ae51f JA |
1658 | hctx->nr_ctx = 0; |
1659 | } | |
1660 | ||
1661 | /* | |
1662 | * Map software to hardware queues | |
1663 | */ | |
1664 | queue_for_each_ctx(q, ctx, i) { | |
1665 | /* If the cpu isn't online, the cpu is mapped to first hctx */ | |
e4043dcf JA |
1666 | if (!cpu_online(i)) |
1667 | continue; | |
1668 | ||
320ae51f | 1669 | hctx = q->mq_ops->map_queue(q, i); |
e4043dcf | 1670 | cpumask_set_cpu(i, hctx->cpumask); |
320ae51f JA |
1671 | ctx->index_hw = hctx->nr_ctx; |
1672 | hctx->ctxs[hctx->nr_ctx++] = ctx; | |
1673 | } | |
506e931f JA |
1674 | |
1675 | queue_for_each_hw_ctx(q, hctx, i) { | |
484b4061 | 1676 | /* |
a68aafa5 JA |
1677 | * If no software queues are mapped to this hardware queue, |
1678 | * disable it and free the request entries. | |
484b4061 JA |
1679 | */ |
1680 | if (!hctx->nr_ctx) { | |
1681 | struct blk_mq_tag_set *set = q->tag_set; | |
1682 | ||
1683 | if (set->tags[i]) { | |
1684 | blk_mq_free_rq_map(set, set->tags[i], i); | |
1685 | set->tags[i] = NULL; | |
1686 | hctx->tags = NULL; | |
1687 | } | |
1688 | continue; | |
1689 | } | |
1690 | ||
1691 | /* | |
1692 | * Initialize batch roundrobin counts | |
1693 | */ | |
506e931f JA |
1694 | hctx->next_cpu = cpumask_first(hctx->cpumask); |
1695 | hctx->next_cpu_batch = BLK_MQ_CPU_WORK_BATCH; | |
1696 | } | |
320ae51f JA |
1697 | } |
1698 | ||
0d2602ca JA |
1699 | static void blk_mq_update_tag_set_depth(struct blk_mq_tag_set *set) |
1700 | { | |
1701 | struct blk_mq_hw_ctx *hctx; | |
1702 | struct request_queue *q; | |
1703 | bool shared; | |
1704 | int i; | |
1705 | ||
1706 | if (set->tag_list.next == set->tag_list.prev) | |
1707 | shared = false; | |
1708 | else | |
1709 | shared = true; | |
1710 | ||
1711 | list_for_each_entry(q, &set->tag_list, tag_set_list) { | |
1712 | blk_mq_freeze_queue(q); | |
1713 | ||
1714 | queue_for_each_hw_ctx(q, hctx, i) { | |
1715 | if (shared) | |
1716 | hctx->flags |= BLK_MQ_F_TAG_SHARED; | |
1717 | else | |
1718 | hctx->flags &= ~BLK_MQ_F_TAG_SHARED; | |
1719 | } | |
1720 | blk_mq_unfreeze_queue(q); | |
1721 | } | |
1722 | } | |
1723 | ||
1724 | static void blk_mq_del_queue_tag_set(struct request_queue *q) | |
1725 | { | |
1726 | struct blk_mq_tag_set *set = q->tag_set; | |
1727 | ||
0d2602ca JA |
1728 | mutex_lock(&set->tag_list_lock); |
1729 | list_del_init(&q->tag_set_list); | |
1730 | blk_mq_update_tag_set_depth(set); | |
1731 | mutex_unlock(&set->tag_list_lock); | |
0d2602ca JA |
1732 | } |
1733 | ||
1734 | static void blk_mq_add_queue_tag_set(struct blk_mq_tag_set *set, | |
1735 | struct request_queue *q) | |
1736 | { | |
1737 | q->tag_set = set; | |
1738 | ||
1739 | mutex_lock(&set->tag_list_lock); | |
1740 | list_add_tail(&q->tag_set_list, &set->tag_list); | |
1741 | blk_mq_update_tag_set_depth(set); | |
1742 | mutex_unlock(&set->tag_list_lock); | |
1743 | } | |
1744 | ||
24d2f903 | 1745 | struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *set) |
320ae51f JA |
1746 | { |
1747 | struct blk_mq_hw_ctx **hctxs; | |
e6cdb092 | 1748 | struct blk_mq_ctx __percpu *ctx; |
320ae51f | 1749 | struct request_queue *q; |
f14bbe77 | 1750 | unsigned int *map; |
320ae51f JA |
1751 | int i; |
1752 | ||
320ae51f JA |
1753 | ctx = alloc_percpu(struct blk_mq_ctx); |
1754 | if (!ctx) | |
1755 | return ERR_PTR(-ENOMEM); | |
1756 | ||
24d2f903 CH |
1757 | hctxs = kmalloc_node(set->nr_hw_queues * sizeof(*hctxs), GFP_KERNEL, |
1758 | set->numa_node); | |
320ae51f JA |
1759 | |
1760 | if (!hctxs) | |
1761 | goto err_percpu; | |
1762 | ||
f14bbe77 JA |
1763 | map = blk_mq_make_queue_map(set); |
1764 | if (!map) | |
1765 | goto err_map; | |
1766 | ||
24d2f903 | 1767 | for (i = 0; i < set->nr_hw_queues; i++) { |
f14bbe77 JA |
1768 | int node = blk_mq_hw_queue_to_node(map, i); |
1769 | ||
cdef54dd CH |
1770 | hctxs[i] = kzalloc_node(sizeof(struct blk_mq_hw_ctx), |
1771 | GFP_KERNEL, node); | |
320ae51f JA |
1772 | if (!hctxs[i]) |
1773 | goto err_hctxs; | |
1774 | ||
e4043dcf JA |
1775 | if (!zalloc_cpumask_var(&hctxs[i]->cpumask, GFP_KERNEL)) |
1776 | goto err_hctxs; | |
1777 | ||
0d2602ca | 1778 | atomic_set(&hctxs[i]->nr_active, 0); |
f14bbe77 | 1779 | hctxs[i]->numa_node = node; |
320ae51f JA |
1780 | hctxs[i]->queue_num = i; |
1781 | } | |
1782 | ||
24d2f903 | 1783 | q = blk_alloc_queue_node(GFP_KERNEL, set->numa_node); |
320ae51f JA |
1784 | if (!q) |
1785 | goto err_hctxs; | |
1786 | ||
add703fd | 1787 | if (percpu_ref_init(&q->mq_usage_counter, blk_mq_usage_counter_release)) |
3d2936f4 ML |
1788 | goto err_map; |
1789 | ||
320ae51f JA |
1790 | setup_timer(&q->timeout, blk_mq_rq_timer, (unsigned long) q); |
1791 | blk_queue_rq_timeout(q, 30000); | |
1792 | ||
1793 | q->nr_queues = nr_cpu_ids; | |
24d2f903 | 1794 | q->nr_hw_queues = set->nr_hw_queues; |
f14bbe77 | 1795 | q->mq_map = map; |
320ae51f JA |
1796 | |
1797 | q->queue_ctx = ctx; | |
1798 | q->queue_hw_ctx = hctxs; | |
1799 | ||
24d2f903 | 1800 | q->mq_ops = set->ops; |
94eddfbe | 1801 | q->queue_flags |= QUEUE_FLAG_MQ_DEFAULT; |
320ae51f | 1802 | |
05f1dd53 JA |
1803 | if (!(set->flags & BLK_MQ_F_SG_MERGE)) |
1804 | q->queue_flags |= 1 << QUEUE_FLAG_NO_SG_MERGE; | |
1805 | ||
1be036e9 CH |
1806 | q->sg_reserved_size = INT_MAX; |
1807 | ||
6fca6a61 CH |
1808 | INIT_WORK(&q->requeue_work, blk_mq_requeue_work); |
1809 | INIT_LIST_HEAD(&q->requeue_list); | |
1810 | spin_lock_init(&q->requeue_lock); | |
1811 | ||
07068d5b JA |
1812 | if (q->nr_hw_queues > 1) |
1813 | blk_queue_make_request(q, blk_mq_make_request); | |
1814 | else | |
1815 | blk_queue_make_request(q, blk_sq_make_request); | |
1816 | ||
87ee7b11 | 1817 | blk_queue_rq_timed_out(q, blk_mq_rq_timed_out); |
24d2f903 CH |
1818 | if (set->timeout) |
1819 | blk_queue_rq_timeout(q, set->timeout); | |
320ae51f | 1820 | |
eba71768 JA |
1821 | /* |
1822 | * Do this after blk_queue_make_request() overrides it... | |
1823 | */ | |
1824 | q->nr_requests = set->queue_depth; | |
1825 | ||
24d2f903 CH |
1826 | if (set->ops->complete) |
1827 | blk_queue_softirq_done(q, set->ops->complete); | |
30a91cb4 | 1828 | |
320ae51f | 1829 | blk_mq_init_flush(q); |
24d2f903 | 1830 | blk_mq_init_cpu_queues(q, set->nr_hw_queues); |
320ae51f | 1831 | |
24d2f903 CH |
1832 | q->flush_rq = kzalloc(round_up(sizeof(struct request) + |
1833 | set->cmd_size, cache_line_size()), | |
1834 | GFP_KERNEL); | |
18741986 | 1835 | if (!q->flush_rq) |
320ae51f JA |
1836 | goto err_hw; |
1837 | ||
24d2f903 | 1838 | if (blk_mq_init_hw_queues(q, set)) |
18741986 CH |
1839 | goto err_flush_rq; |
1840 | ||
320ae51f JA |
1841 | mutex_lock(&all_q_mutex); |
1842 | list_add_tail(&q->all_q_node, &all_q_list); | |
1843 | mutex_unlock(&all_q_mutex); | |
1844 | ||
0d2602ca JA |
1845 | blk_mq_add_queue_tag_set(set, q); |
1846 | ||
484b4061 JA |
1847 | blk_mq_map_swqueue(q); |
1848 | ||
320ae51f | 1849 | return q; |
18741986 CH |
1850 | |
1851 | err_flush_rq: | |
1852 | kfree(q->flush_rq); | |
320ae51f | 1853 | err_hw: |
320ae51f JA |
1854 | blk_cleanup_queue(q); |
1855 | err_hctxs: | |
f14bbe77 | 1856 | kfree(map); |
24d2f903 | 1857 | for (i = 0; i < set->nr_hw_queues; i++) { |
320ae51f JA |
1858 | if (!hctxs[i]) |
1859 | break; | |
e4043dcf | 1860 | free_cpumask_var(hctxs[i]->cpumask); |
cdef54dd | 1861 | kfree(hctxs[i]); |
320ae51f | 1862 | } |
f14bbe77 | 1863 | err_map: |
320ae51f JA |
1864 | kfree(hctxs); |
1865 | err_percpu: | |
1866 | free_percpu(ctx); | |
1867 | return ERR_PTR(-ENOMEM); | |
1868 | } | |
1869 | EXPORT_SYMBOL(blk_mq_init_queue); | |
1870 | ||
1871 | void blk_mq_free_queue(struct request_queue *q) | |
1872 | { | |
624dbe47 | 1873 | struct blk_mq_tag_set *set = q->tag_set; |
320ae51f | 1874 | |
0d2602ca JA |
1875 | blk_mq_del_queue_tag_set(q); |
1876 | ||
624dbe47 ML |
1877 | blk_mq_exit_hw_queues(q, set, set->nr_hw_queues); |
1878 | blk_mq_free_hw_queues(q, set); | |
320ae51f | 1879 | |
add703fd | 1880 | percpu_ref_exit(&q->mq_usage_counter); |
3d2936f4 | 1881 | |
320ae51f JA |
1882 | free_percpu(q->queue_ctx); |
1883 | kfree(q->queue_hw_ctx); | |
1884 | kfree(q->mq_map); | |
1885 | ||
1886 | q->queue_ctx = NULL; | |
1887 | q->queue_hw_ctx = NULL; | |
1888 | q->mq_map = NULL; | |
1889 | ||
1890 | mutex_lock(&all_q_mutex); | |
1891 | list_del_init(&q->all_q_node); | |
1892 | mutex_unlock(&all_q_mutex); | |
1893 | } | |
320ae51f JA |
1894 | |
1895 | /* Basically redo blk_mq_init_queue with queue frozen */ | |
f618ef7c | 1896 | static void blk_mq_queue_reinit(struct request_queue *q) |
320ae51f JA |
1897 | { |
1898 | blk_mq_freeze_queue(q); | |
1899 | ||
67aec14c JA |
1900 | blk_mq_sysfs_unregister(q); |
1901 | ||
320ae51f JA |
1902 | blk_mq_update_queue_map(q->mq_map, q->nr_hw_queues); |
1903 | ||
1904 | /* | |
1905 | * redo blk_mq_init_cpu_queues and blk_mq_init_hw_queues. FIXME: maybe | |
1906 | * we should change hctx numa_node according to new topology (this | |
1907 | * involves free and re-allocate memory, worthy doing?) | |
1908 | */ | |
1909 | ||
1910 | blk_mq_map_swqueue(q); | |
1911 | ||
67aec14c JA |
1912 | blk_mq_sysfs_register(q); |
1913 | ||
320ae51f JA |
1914 | blk_mq_unfreeze_queue(q); |
1915 | } | |
1916 | ||
f618ef7c PG |
1917 | static int blk_mq_queue_reinit_notify(struct notifier_block *nb, |
1918 | unsigned long action, void *hcpu) | |
320ae51f JA |
1919 | { |
1920 | struct request_queue *q; | |
1921 | ||
1922 | /* | |
9fccfed8 JA |
1923 | * Before new mappings are established, hotadded cpu might already |
1924 | * start handling requests. This doesn't break anything as we map | |
1925 | * offline CPUs to first hardware queue. We will re-init the queue | |
1926 | * below to get optimal settings. | |
320ae51f JA |
1927 | */ |
1928 | if (action != CPU_DEAD && action != CPU_DEAD_FROZEN && | |
1929 | action != CPU_ONLINE && action != CPU_ONLINE_FROZEN) | |
1930 | return NOTIFY_OK; | |
1931 | ||
1932 | mutex_lock(&all_q_mutex); | |
1933 | list_for_each_entry(q, &all_q_list, all_q_node) | |
1934 | blk_mq_queue_reinit(q); | |
1935 | mutex_unlock(&all_q_mutex); | |
1936 | return NOTIFY_OK; | |
1937 | } | |
1938 | ||
a4391c64 JA |
1939 | /* |
1940 | * Alloc a tag set to be associated with one or more request queues. | |
1941 | * May fail with EINVAL for various error conditions. May adjust the | |
1942 | * requested depth down, if if it too large. In that case, the set | |
1943 | * value will be stored in set->queue_depth. | |
1944 | */ | |
24d2f903 CH |
1945 | int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set) |
1946 | { | |
1947 | int i; | |
1948 | ||
1949 | if (!set->nr_hw_queues) | |
1950 | return -EINVAL; | |
a4391c64 | 1951 | if (!set->queue_depth) |
24d2f903 CH |
1952 | return -EINVAL; |
1953 | if (set->queue_depth < set->reserved_tags + BLK_MQ_TAG_MIN) | |
1954 | return -EINVAL; | |
1955 | ||
cdef54dd | 1956 | if (!set->nr_hw_queues || !set->ops->queue_rq || !set->ops->map_queue) |
24d2f903 CH |
1957 | return -EINVAL; |
1958 | ||
a4391c64 JA |
1959 | if (set->queue_depth > BLK_MQ_MAX_DEPTH) { |
1960 | pr_info("blk-mq: reduced tag depth to %u\n", | |
1961 | BLK_MQ_MAX_DEPTH); | |
1962 | set->queue_depth = BLK_MQ_MAX_DEPTH; | |
1963 | } | |
24d2f903 | 1964 | |
48479005 ML |
1965 | set->tags = kmalloc_node(set->nr_hw_queues * |
1966 | sizeof(struct blk_mq_tags *), | |
24d2f903 CH |
1967 | GFP_KERNEL, set->numa_node); |
1968 | if (!set->tags) | |
1969 | goto out; | |
1970 | ||
1971 | for (i = 0; i < set->nr_hw_queues; i++) { | |
1972 | set->tags[i] = blk_mq_init_rq_map(set, i); | |
1973 | if (!set->tags[i]) | |
1974 | goto out_unwind; | |
1975 | } | |
1976 | ||
0d2602ca JA |
1977 | mutex_init(&set->tag_list_lock); |
1978 | INIT_LIST_HEAD(&set->tag_list); | |
1979 | ||
24d2f903 CH |
1980 | return 0; |
1981 | ||
1982 | out_unwind: | |
1983 | while (--i >= 0) | |
1984 | blk_mq_free_rq_map(set, set->tags[i], i); | |
1985 | out: | |
1986 | return -ENOMEM; | |
1987 | } | |
1988 | EXPORT_SYMBOL(blk_mq_alloc_tag_set); | |
1989 | ||
1990 | void blk_mq_free_tag_set(struct blk_mq_tag_set *set) | |
1991 | { | |
1992 | int i; | |
1993 | ||
484b4061 JA |
1994 | for (i = 0; i < set->nr_hw_queues; i++) { |
1995 | if (set->tags[i]) | |
1996 | blk_mq_free_rq_map(set, set->tags[i], i); | |
1997 | } | |
1998 | ||
981bd189 | 1999 | kfree(set->tags); |
24d2f903 CH |
2000 | } |
2001 | EXPORT_SYMBOL(blk_mq_free_tag_set); | |
2002 | ||
e3a2b3f9 JA |
2003 | int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr) |
2004 | { | |
2005 | struct blk_mq_tag_set *set = q->tag_set; | |
2006 | struct blk_mq_hw_ctx *hctx; | |
2007 | int i, ret; | |
2008 | ||
2009 | if (!set || nr > set->queue_depth) | |
2010 | return -EINVAL; | |
2011 | ||
2012 | ret = 0; | |
2013 | queue_for_each_hw_ctx(q, hctx, i) { | |
2014 | ret = blk_mq_tag_update_depth(hctx->tags, nr); | |
2015 | if (ret) | |
2016 | break; | |
2017 | } | |
2018 | ||
2019 | if (!ret) | |
2020 | q->nr_requests = nr; | |
2021 | ||
2022 | return ret; | |
2023 | } | |
2024 | ||
676141e4 JA |
2025 | void blk_mq_disable_hotplug(void) |
2026 | { | |
2027 | mutex_lock(&all_q_mutex); | |
2028 | } | |
2029 | ||
2030 | void blk_mq_enable_hotplug(void) | |
2031 | { | |
2032 | mutex_unlock(&all_q_mutex); | |
2033 | } | |
2034 | ||
320ae51f JA |
2035 | static int __init blk_mq_init(void) |
2036 | { | |
320ae51f JA |
2037 | blk_mq_cpu_init(); |
2038 | ||
add703fd | 2039 | hotcpu_notifier(blk_mq_queue_reinit_notify, 0); |
320ae51f JA |
2040 | |
2041 | return 0; | |
2042 | } | |
2043 | subsys_initcall(blk_mq_init); |