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Commit | Line | Data |
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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> | |
f75782e4 | 12 | #include <linux/kmemleak.h> |
320ae51f JA |
13 | #include <linux/mm.h> |
14 | #include <linux/init.h> | |
15 | #include <linux/slab.h> | |
16 | #include <linux/workqueue.h> | |
17 | #include <linux/smp.h> | |
18 | #include <linux/llist.h> | |
19 | #include <linux/list_sort.h> | |
20 | #include <linux/cpu.h> | |
21 | #include <linux/cache.h> | |
22 | #include <linux/sched/sysctl.h> | |
23 | #include <linux/delay.h> | |
aedcd72f | 24 | #include <linux/crash_dump.h> |
320ae51f JA |
25 | |
26 | #include <trace/events/block.h> | |
27 | ||
28 | #include <linux/blk-mq.h> | |
29 | #include "blk.h" | |
30 | #include "blk-mq.h" | |
31 | #include "blk-mq-tag.h" | |
32 | ||
33 | static DEFINE_MUTEX(all_q_mutex); | |
34 | static LIST_HEAD(all_q_list); | |
35 | ||
36 | static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx); | |
37 | ||
320ae51f JA |
38 | /* |
39 | * Check if any of the ctx's have pending work in this hardware queue | |
40 | */ | |
41 | static bool blk_mq_hctx_has_pending(struct blk_mq_hw_ctx *hctx) | |
42 | { | |
43 | unsigned int i; | |
44 | ||
569fd0ce | 45 | for (i = 0; i < hctx->ctx_map.size; i++) |
1429d7c9 | 46 | if (hctx->ctx_map.map[i].word) |
320ae51f JA |
47 | return true; |
48 | ||
49 | return false; | |
50 | } | |
51 | ||
1429d7c9 JA |
52 | static inline struct blk_align_bitmap *get_bm(struct blk_mq_hw_ctx *hctx, |
53 | struct blk_mq_ctx *ctx) | |
54 | { | |
55 | return &hctx->ctx_map.map[ctx->index_hw / hctx->ctx_map.bits_per_word]; | |
56 | } | |
57 | ||
58 | #define CTX_TO_BIT(hctx, ctx) \ | |
59 | ((ctx)->index_hw & ((hctx)->ctx_map.bits_per_word - 1)) | |
60 | ||
320ae51f JA |
61 | /* |
62 | * Mark this ctx as having pending work in this hardware queue | |
63 | */ | |
64 | static void blk_mq_hctx_mark_pending(struct blk_mq_hw_ctx *hctx, | |
65 | struct blk_mq_ctx *ctx) | |
66 | { | |
1429d7c9 JA |
67 | struct blk_align_bitmap *bm = get_bm(hctx, ctx); |
68 | ||
69 | if (!test_bit(CTX_TO_BIT(hctx, ctx), &bm->word)) | |
70 | set_bit(CTX_TO_BIT(hctx, ctx), &bm->word); | |
71 | } | |
72 | ||
73 | static void blk_mq_hctx_clear_pending(struct blk_mq_hw_ctx *hctx, | |
74 | struct blk_mq_ctx *ctx) | |
75 | { | |
76 | struct blk_align_bitmap *bm = get_bm(hctx, ctx); | |
77 | ||
78 | clear_bit(CTX_TO_BIT(hctx, ctx), &bm->word); | |
320ae51f JA |
79 | } |
80 | ||
b4c6a028 | 81 | void blk_mq_freeze_queue_start(struct request_queue *q) |
43a5e4e2 | 82 | { |
4ecd4fef | 83 | int freeze_depth; |
cddd5d17 | 84 | |
4ecd4fef CH |
85 | freeze_depth = atomic_inc_return(&q->mq_freeze_depth); |
86 | if (freeze_depth == 1) { | |
3ef28e83 | 87 | percpu_ref_kill(&q->q_usage_counter); |
b94ec296 | 88 | blk_mq_run_hw_queues(q, false); |
cddd5d17 | 89 | } |
f3af020b | 90 | } |
b4c6a028 | 91 | EXPORT_SYMBOL_GPL(blk_mq_freeze_queue_start); |
f3af020b TH |
92 | |
93 | static void blk_mq_freeze_queue_wait(struct request_queue *q) | |
94 | { | |
3ef28e83 | 95 | wait_event(q->mq_freeze_wq, percpu_ref_is_zero(&q->q_usage_counter)); |
43a5e4e2 ML |
96 | } |
97 | ||
f3af020b TH |
98 | /* |
99 | * Guarantee no request is in use, so we can change any data structure of | |
100 | * the queue afterward. | |
101 | */ | |
3ef28e83 | 102 | void blk_freeze_queue(struct request_queue *q) |
f3af020b | 103 | { |
3ef28e83 DW |
104 | /* |
105 | * In the !blk_mq case we are only calling this to kill the | |
106 | * q_usage_counter, otherwise this increases the freeze depth | |
107 | * and waits for it to return to zero. For this reason there is | |
108 | * no blk_unfreeze_queue(), and blk_freeze_queue() is not | |
109 | * exported to drivers as the only user for unfreeze is blk_mq. | |
110 | */ | |
f3af020b TH |
111 | blk_mq_freeze_queue_start(q); |
112 | blk_mq_freeze_queue_wait(q); | |
113 | } | |
3ef28e83 DW |
114 | |
115 | void blk_mq_freeze_queue(struct request_queue *q) | |
116 | { | |
117 | /* | |
118 | * ...just an alias to keep freeze and unfreeze actions balanced | |
119 | * in the blk_mq_* namespace | |
120 | */ | |
121 | blk_freeze_queue(q); | |
122 | } | |
c761d96b | 123 | EXPORT_SYMBOL_GPL(blk_mq_freeze_queue); |
f3af020b | 124 | |
b4c6a028 | 125 | void blk_mq_unfreeze_queue(struct request_queue *q) |
320ae51f | 126 | { |
4ecd4fef | 127 | int freeze_depth; |
320ae51f | 128 | |
4ecd4fef CH |
129 | freeze_depth = atomic_dec_return(&q->mq_freeze_depth); |
130 | WARN_ON_ONCE(freeze_depth < 0); | |
131 | if (!freeze_depth) { | |
3ef28e83 | 132 | percpu_ref_reinit(&q->q_usage_counter); |
320ae51f | 133 | wake_up_all(&q->mq_freeze_wq); |
add703fd | 134 | } |
320ae51f | 135 | } |
b4c6a028 | 136 | EXPORT_SYMBOL_GPL(blk_mq_unfreeze_queue); |
320ae51f | 137 | |
aed3ea94 JA |
138 | void blk_mq_wake_waiters(struct request_queue *q) |
139 | { | |
140 | struct blk_mq_hw_ctx *hctx; | |
141 | unsigned int i; | |
142 | ||
143 | queue_for_each_hw_ctx(q, hctx, i) | |
144 | if (blk_mq_hw_queue_mapped(hctx)) | |
145 | blk_mq_tag_wakeup_all(hctx->tags, true); | |
3fd5940c KB |
146 | |
147 | /* | |
148 | * If we are called because the queue has now been marked as | |
149 | * dying, we need to ensure that processes currently waiting on | |
150 | * the queue are notified as well. | |
151 | */ | |
152 | wake_up_all(&q->mq_freeze_wq); | |
aed3ea94 JA |
153 | } |
154 | ||
320ae51f JA |
155 | bool blk_mq_can_queue(struct blk_mq_hw_ctx *hctx) |
156 | { | |
157 | return blk_mq_has_free_tags(hctx->tags); | |
158 | } | |
159 | EXPORT_SYMBOL(blk_mq_can_queue); | |
160 | ||
94eddfbe | 161 | static void blk_mq_rq_ctx_init(struct request_queue *q, struct blk_mq_ctx *ctx, |
cc6e3b10 MC |
162 | struct request *rq, int op, |
163 | unsigned int op_flags) | |
320ae51f | 164 | { |
94eddfbe | 165 | if (blk_queue_io_stat(q)) |
cc6e3b10 | 166 | op_flags |= REQ_IO_STAT; |
94eddfbe | 167 | |
af76e555 CH |
168 | INIT_LIST_HEAD(&rq->queuelist); |
169 | /* csd/requeue_work/fifo_time is initialized before use */ | |
170 | rq->q = q; | |
320ae51f | 171 | rq->mq_ctx = ctx; |
cc6e3b10 | 172 | req_set_op_attrs(rq, op, op_flags); |
af76e555 CH |
173 | /* do not touch atomic flags, it needs atomic ops against the timer */ |
174 | rq->cpu = -1; | |
af76e555 CH |
175 | INIT_HLIST_NODE(&rq->hash); |
176 | RB_CLEAR_NODE(&rq->rb_node); | |
af76e555 CH |
177 | rq->rq_disk = NULL; |
178 | rq->part = NULL; | |
3ee32372 | 179 | rq->start_time = jiffies; |
af76e555 CH |
180 | #ifdef CONFIG_BLK_CGROUP |
181 | rq->rl = NULL; | |
0fec08b4 | 182 | set_start_time_ns(rq); |
af76e555 CH |
183 | rq->io_start_time_ns = 0; |
184 | #endif | |
185 | rq->nr_phys_segments = 0; | |
186 | #if defined(CONFIG_BLK_DEV_INTEGRITY) | |
187 | rq->nr_integrity_segments = 0; | |
188 | #endif | |
af76e555 CH |
189 | rq->special = NULL; |
190 | /* tag was already set */ | |
191 | rq->errors = 0; | |
af76e555 | 192 | |
6f4a1626 TB |
193 | rq->cmd = rq->__cmd; |
194 | ||
af76e555 CH |
195 | rq->extra_len = 0; |
196 | rq->sense_len = 0; | |
197 | rq->resid_len = 0; | |
198 | rq->sense = NULL; | |
199 | ||
af76e555 | 200 | INIT_LIST_HEAD(&rq->timeout_list); |
f6be4fb4 JA |
201 | rq->timeout = 0; |
202 | ||
af76e555 CH |
203 | rq->end_io = NULL; |
204 | rq->end_io_data = NULL; | |
205 | rq->next_rq = NULL; | |
206 | ||
d9d8c5c4 | 207 | ctx->rq_dispatched[rw_is_sync(op, op_flags)]++; |
320ae51f JA |
208 | } |
209 | ||
5dee8577 | 210 | static struct request * |
cc6e3b10 | 211 | __blk_mq_alloc_request(struct blk_mq_alloc_data *data, int op, int op_flags) |
5dee8577 CH |
212 | { |
213 | struct request *rq; | |
214 | unsigned int tag; | |
215 | ||
cb96a42c | 216 | tag = blk_mq_get_tag(data); |
5dee8577 | 217 | if (tag != BLK_MQ_TAG_FAIL) { |
cb96a42c | 218 | rq = data->hctx->tags->rqs[tag]; |
5dee8577 | 219 | |
cb96a42c | 220 | if (blk_mq_tag_busy(data->hctx)) { |
5dee8577 | 221 | rq->cmd_flags = REQ_MQ_INFLIGHT; |
cb96a42c | 222 | atomic_inc(&data->hctx->nr_active); |
5dee8577 CH |
223 | } |
224 | ||
225 | rq->tag = tag; | |
cc6e3b10 | 226 | blk_mq_rq_ctx_init(data->q, data->ctx, rq, op, op_flags); |
5dee8577 CH |
227 | return rq; |
228 | } | |
229 | ||
230 | return NULL; | |
231 | } | |
232 | ||
6f3b0e8b CH |
233 | struct request *blk_mq_alloc_request(struct request_queue *q, int rw, |
234 | unsigned int flags) | |
320ae51f | 235 | { |
d852564f CH |
236 | struct blk_mq_ctx *ctx; |
237 | struct blk_mq_hw_ctx *hctx; | |
320ae51f | 238 | struct request *rq; |
cb96a42c | 239 | struct blk_mq_alloc_data alloc_data; |
a492f075 | 240 | int ret; |
320ae51f | 241 | |
6f3b0e8b | 242 | ret = blk_queue_enter(q, flags & BLK_MQ_REQ_NOWAIT); |
a492f075 JL |
243 | if (ret) |
244 | return ERR_PTR(ret); | |
320ae51f | 245 | |
d852564f CH |
246 | ctx = blk_mq_get_ctx(q); |
247 | hctx = q->mq_ops->map_queue(q, ctx->cpu); | |
6f3b0e8b | 248 | blk_mq_set_alloc_data(&alloc_data, q, flags, ctx, hctx); |
d852564f | 249 | |
cc6e3b10 | 250 | rq = __blk_mq_alloc_request(&alloc_data, rw, 0); |
6f3b0e8b | 251 | if (!rq && !(flags & BLK_MQ_REQ_NOWAIT)) { |
d852564f CH |
252 | __blk_mq_run_hw_queue(hctx); |
253 | blk_mq_put_ctx(ctx); | |
254 | ||
255 | ctx = blk_mq_get_ctx(q); | |
256 | hctx = q->mq_ops->map_queue(q, ctx->cpu); | |
6f3b0e8b | 257 | blk_mq_set_alloc_data(&alloc_data, q, flags, ctx, hctx); |
cc6e3b10 | 258 | rq = __blk_mq_alloc_request(&alloc_data, rw, 0); |
cb96a42c | 259 | ctx = alloc_data.ctx; |
d852564f CH |
260 | } |
261 | blk_mq_put_ctx(ctx); | |
c76541a9 | 262 | if (!rq) { |
3ef28e83 | 263 | blk_queue_exit(q); |
a492f075 | 264 | return ERR_PTR(-EWOULDBLOCK); |
c76541a9 | 265 | } |
0c4de0f3 CH |
266 | |
267 | rq->__data_len = 0; | |
268 | rq->__sector = (sector_t) -1; | |
269 | rq->bio = rq->biotail = NULL; | |
320ae51f JA |
270 | return rq; |
271 | } | |
4bb659b1 | 272 | EXPORT_SYMBOL(blk_mq_alloc_request); |
320ae51f | 273 | |
1f5bd336 ML |
274 | struct request *blk_mq_alloc_request_hctx(struct request_queue *q, int rw, |
275 | unsigned int flags, unsigned int hctx_idx) | |
276 | { | |
277 | struct blk_mq_hw_ctx *hctx; | |
278 | struct blk_mq_ctx *ctx; | |
279 | struct request *rq; | |
280 | struct blk_mq_alloc_data alloc_data; | |
281 | int ret; | |
282 | ||
283 | /* | |
284 | * If the tag allocator sleeps we could get an allocation for a | |
285 | * different hardware context. No need to complicate the low level | |
286 | * allocator for this for the rare use case of a command tied to | |
287 | * a specific queue. | |
288 | */ | |
289 | if (WARN_ON_ONCE(!(flags & BLK_MQ_REQ_NOWAIT))) | |
290 | return ERR_PTR(-EINVAL); | |
291 | ||
292 | if (hctx_idx >= q->nr_hw_queues) | |
293 | return ERR_PTR(-EIO); | |
294 | ||
295 | ret = blk_queue_enter(q, true); | |
296 | if (ret) | |
297 | return ERR_PTR(ret); | |
298 | ||
c8712c6a CH |
299 | /* |
300 | * Check if the hardware context is actually mapped to anything. | |
301 | * If not tell the caller that it should skip this queue. | |
302 | */ | |
1f5bd336 | 303 | hctx = q->queue_hw_ctx[hctx_idx]; |
c8712c6a CH |
304 | if (!blk_mq_hw_queue_mapped(hctx)) { |
305 | ret = -EXDEV; | |
306 | goto out_queue_exit; | |
307 | } | |
1f5bd336 ML |
308 | ctx = __blk_mq_get_ctx(q, cpumask_first(hctx->cpumask)); |
309 | ||
310 | blk_mq_set_alloc_data(&alloc_data, q, flags, ctx, hctx); | |
311 | rq = __blk_mq_alloc_request(&alloc_data, rw, 0); | |
312 | if (!rq) { | |
c8712c6a CH |
313 | ret = -EWOULDBLOCK; |
314 | goto out_queue_exit; | |
1f5bd336 ML |
315 | } |
316 | ||
317 | return rq; | |
c8712c6a CH |
318 | |
319 | out_queue_exit: | |
320 | blk_queue_exit(q); | |
321 | return ERR_PTR(ret); | |
1f5bd336 ML |
322 | } |
323 | EXPORT_SYMBOL_GPL(blk_mq_alloc_request_hctx); | |
324 | ||
320ae51f JA |
325 | static void __blk_mq_free_request(struct blk_mq_hw_ctx *hctx, |
326 | struct blk_mq_ctx *ctx, struct request *rq) | |
327 | { | |
328 | const int tag = rq->tag; | |
329 | struct request_queue *q = rq->q; | |
330 | ||
0d2602ca JA |
331 | if (rq->cmd_flags & REQ_MQ_INFLIGHT) |
332 | atomic_dec(&hctx->nr_active); | |
683d0e12 | 333 | rq->cmd_flags = 0; |
0d2602ca | 334 | |
af76e555 | 335 | clear_bit(REQ_ATOM_STARTED, &rq->atomic_flags); |
0d2602ca | 336 | blk_mq_put_tag(hctx, tag, &ctx->last_tag); |
3ef28e83 | 337 | blk_queue_exit(q); |
320ae51f JA |
338 | } |
339 | ||
7c7f2f2b | 340 | void blk_mq_free_hctx_request(struct blk_mq_hw_ctx *hctx, struct request *rq) |
320ae51f JA |
341 | { |
342 | struct blk_mq_ctx *ctx = rq->mq_ctx; | |
320ae51f JA |
343 | |
344 | ctx->rq_completed[rq_is_sync(rq)]++; | |
320ae51f | 345 | __blk_mq_free_request(hctx, ctx, rq); |
7c7f2f2b JA |
346 | |
347 | } | |
348 | EXPORT_SYMBOL_GPL(blk_mq_free_hctx_request); | |
349 | ||
350 | void blk_mq_free_request(struct request *rq) | |
351 | { | |
352 | struct blk_mq_hw_ctx *hctx; | |
353 | struct request_queue *q = rq->q; | |
354 | ||
355 | hctx = q->mq_ops->map_queue(q, rq->mq_ctx->cpu); | |
356 | blk_mq_free_hctx_request(hctx, rq); | |
320ae51f | 357 | } |
1a3b595a | 358 | EXPORT_SYMBOL_GPL(blk_mq_free_request); |
320ae51f | 359 | |
c8a446ad | 360 | inline void __blk_mq_end_request(struct request *rq, int error) |
320ae51f | 361 | { |
0d11e6ac ML |
362 | blk_account_io_done(rq); |
363 | ||
91b63639 | 364 | if (rq->end_io) { |
320ae51f | 365 | rq->end_io(rq, error); |
91b63639 CH |
366 | } else { |
367 | if (unlikely(blk_bidi_rq(rq))) | |
368 | blk_mq_free_request(rq->next_rq); | |
320ae51f | 369 | blk_mq_free_request(rq); |
91b63639 | 370 | } |
320ae51f | 371 | } |
c8a446ad | 372 | EXPORT_SYMBOL(__blk_mq_end_request); |
63151a44 | 373 | |
c8a446ad | 374 | void blk_mq_end_request(struct request *rq, int error) |
63151a44 CH |
375 | { |
376 | if (blk_update_request(rq, error, blk_rq_bytes(rq))) | |
377 | BUG(); | |
c8a446ad | 378 | __blk_mq_end_request(rq, error); |
63151a44 | 379 | } |
c8a446ad | 380 | EXPORT_SYMBOL(blk_mq_end_request); |
320ae51f | 381 | |
30a91cb4 | 382 | static void __blk_mq_complete_request_remote(void *data) |
320ae51f | 383 | { |
3d6efbf6 | 384 | struct request *rq = data; |
320ae51f | 385 | |
30a91cb4 | 386 | rq->q->softirq_done_fn(rq); |
320ae51f | 387 | } |
320ae51f | 388 | |
ed851860 | 389 | static void blk_mq_ipi_complete_request(struct request *rq) |
320ae51f JA |
390 | { |
391 | struct blk_mq_ctx *ctx = rq->mq_ctx; | |
38535201 | 392 | bool shared = false; |
320ae51f JA |
393 | int cpu; |
394 | ||
38535201 | 395 | if (!test_bit(QUEUE_FLAG_SAME_COMP, &rq->q->queue_flags)) { |
30a91cb4 CH |
396 | rq->q->softirq_done_fn(rq); |
397 | return; | |
398 | } | |
320ae51f JA |
399 | |
400 | cpu = get_cpu(); | |
38535201 CH |
401 | if (!test_bit(QUEUE_FLAG_SAME_FORCE, &rq->q->queue_flags)) |
402 | shared = cpus_share_cache(cpu, ctx->cpu); | |
403 | ||
404 | if (cpu != ctx->cpu && !shared && cpu_online(ctx->cpu)) { | |
30a91cb4 | 405 | rq->csd.func = __blk_mq_complete_request_remote; |
3d6efbf6 CH |
406 | rq->csd.info = rq; |
407 | rq->csd.flags = 0; | |
c46fff2a | 408 | smp_call_function_single_async(ctx->cpu, &rq->csd); |
3d6efbf6 | 409 | } else { |
30a91cb4 | 410 | rq->q->softirq_done_fn(rq); |
3d6efbf6 | 411 | } |
320ae51f JA |
412 | put_cpu(); |
413 | } | |
30a91cb4 | 414 | |
1fa8cc52 | 415 | static void __blk_mq_complete_request(struct request *rq) |
ed851860 JA |
416 | { |
417 | struct request_queue *q = rq->q; | |
418 | ||
419 | if (!q->softirq_done_fn) | |
c8a446ad | 420 | blk_mq_end_request(rq, rq->errors); |
ed851860 JA |
421 | else |
422 | blk_mq_ipi_complete_request(rq); | |
423 | } | |
424 | ||
30a91cb4 CH |
425 | /** |
426 | * blk_mq_complete_request - end I/O on a request | |
427 | * @rq: the request being processed | |
428 | * | |
429 | * Description: | |
430 | * Ends all I/O on a request. It does not handle partial completions. | |
431 | * The actual completion happens out-of-order, through a IPI handler. | |
432 | **/ | |
f4829a9b | 433 | void blk_mq_complete_request(struct request *rq, int error) |
30a91cb4 | 434 | { |
95f09684 JA |
435 | struct request_queue *q = rq->q; |
436 | ||
437 | if (unlikely(blk_should_fake_timeout(q))) | |
30a91cb4 | 438 | return; |
f4829a9b CH |
439 | if (!blk_mark_rq_complete(rq)) { |
440 | rq->errors = error; | |
ed851860 | 441 | __blk_mq_complete_request(rq); |
f4829a9b | 442 | } |
30a91cb4 CH |
443 | } |
444 | EXPORT_SYMBOL(blk_mq_complete_request); | |
320ae51f | 445 | |
973c0191 KB |
446 | int blk_mq_request_started(struct request *rq) |
447 | { | |
448 | return test_bit(REQ_ATOM_STARTED, &rq->atomic_flags); | |
449 | } | |
450 | EXPORT_SYMBOL_GPL(blk_mq_request_started); | |
451 | ||
e2490073 | 452 | void blk_mq_start_request(struct request *rq) |
320ae51f JA |
453 | { |
454 | struct request_queue *q = rq->q; | |
455 | ||
456 | trace_block_rq_issue(q, rq); | |
457 | ||
742ee69b | 458 | rq->resid_len = blk_rq_bytes(rq); |
91b63639 CH |
459 | if (unlikely(blk_bidi_rq(rq))) |
460 | rq->next_rq->resid_len = blk_rq_bytes(rq->next_rq); | |
742ee69b | 461 | |
2b8393b4 | 462 | blk_add_timer(rq); |
87ee7b11 | 463 | |
538b7534 JA |
464 | /* |
465 | * Ensure that ->deadline is visible before set the started | |
466 | * flag and clear the completed flag. | |
467 | */ | |
468 | smp_mb__before_atomic(); | |
469 | ||
87ee7b11 JA |
470 | /* |
471 | * Mark us as started and clear complete. Complete might have been | |
472 | * set if requeue raced with timeout, which then marked it as | |
473 | * complete. So be sure to clear complete again when we start | |
474 | * the request, otherwise we'll ignore the completion event. | |
475 | */ | |
4b570521 JA |
476 | if (!test_bit(REQ_ATOM_STARTED, &rq->atomic_flags)) |
477 | set_bit(REQ_ATOM_STARTED, &rq->atomic_flags); | |
478 | if (test_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags)) | |
479 | clear_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags); | |
49f5baa5 CH |
480 | |
481 | if (q->dma_drain_size && blk_rq_bytes(rq)) { | |
482 | /* | |
483 | * Make sure space for the drain appears. We know we can do | |
484 | * this because max_hw_segments has been adjusted to be one | |
485 | * fewer than the device can handle. | |
486 | */ | |
487 | rq->nr_phys_segments++; | |
488 | } | |
320ae51f | 489 | } |
e2490073 | 490 | EXPORT_SYMBOL(blk_mq_start_request); |
320ae51f | 491 | |
ed0791b2 | 492 | static void __blk_mq_requeue_request(struct request *rq) |
320ae51f JA |
493 | { |
494 | struct request_queue *q = rq->q; | |
495 | ||
496 | trace_block_rq_requeue(q, rq); | |
49f5baa5 | 497 | |
e2490073 CH |
498 | if (test_and_clear_bit(REQ_ATOM_STARTED, &rq->atomic_flags)) { |
499 | if (q->dma_drain_size && blk_rq_bytes(rq)) | |
500 | rq->nr_phys_segments--; | |
501 | } | |
320ae51f JA |
502 | } |
503 | ||
ed0791b2 CH |
504 | void blk_mq_requeue_request(struct request *rq) |
505 | { | |
ed0791b2 | 506 | __blk_mq_requeue_request(rq); |
ed0791b2 | 507 | |
ed0791b2 | 508 | BUG_ON(blk_queued_rq(rq)); |
6fca6a61 | 509 | blk_mq_add_to_requeue_list(rq, true); |
ed0791b2 CH |
510 | } |
511 | EXPORT_SYMBOL(blk_mq_requeue_request); | |
512 | ||
6fca6a61 CH |
513 | static void blk_mq_requeue_work(struct work_struct *work) |
514 | { | |
515 | struct request_queue *q = | |
516 | container_of(work, struct request_queue, requeue_work); | |
517 | LIST_HEAD(rq_list); | |
518 | struct request *rq, *next; | |
519 | unsigned long flags; | |
520 | ||
521 | spin_lock_irqsave(&q->requeue_lock, flags); | |
522 | list_splice_init(&q->requeue_list, &rq_list); | |
523 | spin_unlock_irqrestore(&q->requeue_lock, flags); | |
524 | ||
525 | list_for_each_entry_safe(rq, next, &rq_list, queuelist) { | |
526 | if (!(rq->cmd_flags & REQ_SOFTBARRIER)) | |
527 | continue; | |
528 | ||
529 | rq->cmd_flags &= ~REQ_SOFTBARRIER; | |
530 | list_del_init(&rq->queuelist); | |
531 | blk_mq_insert_request(rq, true, false, false); | |
532 | } | |
533 | ||
534 | while (!list_empty(&rq_list)) { | |
535 | rq = list_entry(rq_list.next, struct request, queuelist); | |
536 | list_del_init(&rq->queuelist); | |
537 | blk_mq_insert_request(rq, false, false, false); | |
538 | } | |
539 | ||
8b957415 JA |
540 | /* |
541 | * Use the start variant of queue running here, so that running | |
542 | * the requeue work will kick stopped queues. | |
543 | */ | |
544 | blk_mq_start_hw_queues(q); | |
6fca6a61 CH |
545 | } |
546 | ||
547 | void blk_mq_add_to_requeue_list(struct request *rq, bool at_head) | |
548 | { | |
549 | struct request_queue *q = rq->q; | |
550 | unsigned long flags; | |
551 | ||
552 | /* | |
553 | * We abuse this flag that is otherwise used by the I/O scheduler to | |
554 | * request head insertation from the workqueue. | |
555 | */ | |
556 | BUG_ON(rq->cmd_flags & REQ_SOFTBARRIER); | |
557 | ||
558 | spin_lock_irqsave(&q->requeue_lock, flags); | |
559 | if (at_head) { | |
560 | rq->cmd_flags |= REQ_SOFTBARRIER; | |
561 | list_add(&rq->queuelist, &q->requeue_list); | |
562 | } else { | |
563 | list_add_tail(&rq->queuelist, &q->requeue_list); | |
564 | } | |
565 | spin_unlock_irqrestore(&q->requeue_lock, flags); | |
566 | } | |
567 | EXPORT_SYMBOL(blk_mq_add_to_requeue_list); | |
568 | ||
c68ed59f KB |
569 | void blk_mq_cancel_requeue_work(struct request_queue *q) |
570 | { | |
571 | cancel_work_sync(&q->requeue_work); | |
572 | } | |
573 | EXPORT_SYMBOL_GPL(blk_mq_cancel_requeue_work); | |
574 | ||
6fca6a61 CH |
575 | void blk_mq_kick_requeue_list(struct request_queue *q) |
576 | { | |
577 | kblockd_schedule_work(&q->requeue_work); | |
578 | } | |
579 | EXPORT_SYMBOL(blk_mq_kick_requeue_list); | |
580 | ||
1885b24d JA |
581 | void blk_mq_abort_requeue_list(struct request_queue *q) |
582 | { | |
583 | unsigned long flags; | |
584 | LIST_HEAD(rq_list); | |
585 | ||
586 | spin_lock_irqsave(&q->requeue_lock, flags); | |
587 | list_splice_init(&q->requeue_list, &rq_list); | |
588 | spin_unlock_irqrestore(&q->requeue_lock, flags); | |
589 | ||
590 | while (!list_empty(&rq_list)) { | |
591 | struct request *rq; | |
592 | ||
593 | rq = list_first_entry(&rq_list, struct request, queuelist); | |
594 | list_del_init(&rq->queuelist); | |
595 | rq->errors = -EIO; | |
596 | blk_mq_end_request(rq, rq->errors); | |
597 | } | |
598 | } | |
599 | EXPORT_SYMBOL(blk_mq_abort_requeue_list); | |
600 | ||
0e62f51f JA |
601 | struct request *blk_mq_tag_to_rq(struct blk_mq_tags *tags, unsigned int tag) |
602 | { | |
4ee86bab HR |
603 | if (tag < tags->nr_tags) |
604 | return tags->rqs[tag]; | |
605 | ||
606 | return NULL; | |
24d2f903 CH |
607 | } |
608 | EXPORT_SYMBOL(blk_mq_tag_to_rq); | |
609 | ||
320ae51f | 610 | struct blk_mq_timeout_data { |
46f92d42 CH |
611 | unsigned long next; |
612 | unsigned int next_set; | |
320ae51f JA |
613 | }; |
614 | ||
90415837 | 615 | void blk_mq_rq_timed_out(struct request *req, bool reserved) |
320ae51f | 616 | { |
46f92d42 CH |
617 | struct blk_mq_ops *ops = req->q->mq_ops; |
618 | enum blk_eh_timer_return ret = BLK_EH_RESET_TIMER; | |
87ee7b11 JA |
619 | |
620 | /* | |
621 | * We know that complete is set at this point. If STARTED isn't set | |
622 | * anymore, then the request isn't active and the "timeout" should | |
623 | * just be ignored. This can happen due to the bitflag ordering. | |
624 | * Timeout first checks if STARTED is set, and if it is, assumes | |
625 | * the request is active. But if we race with completion, then | |
626 | * we both flags will get cleared. So check here again, and ignore | |
627 | * a timeout event with a request that isn't active. | |
628 | */ | |
46f92d42 CH |
629 | if (!test_bit(REQ_ATOM_STARTED, &req->atomic_flags)) |
630 | return; | |
87ee7b11 | 631 | |
46f92d42 | 632 | if (ops->timeout) |
0152fb6b | 633 | ret = ops->timeout(req, reserved); |
46f92d42 CH |
634 | |
635 | switch (ret) { | |
636 | case BLK_EH_HANDLED: | |
637 | __blk_mq_complete_request(req); | |
638 | break; | |
639 | case BLK_EH_RESET_TIMER: | |
640 | blk_add_timer(req); | |
641 | blk_clear_rq_complete(req); | |
642 | break; | |
643 | case BLK_EH_NOT_HANDLED: | |
644 | break; | |
645 | default: | |
646 | printk(KERN_ERR "block: bad eh return: %d\n", ret); | |
647 | break; | |
648 | } | |
87ee7b11 | 649 | } |
5b3f25fc | 650 | |
81481eb4 CH |
651 | static void blk_mq_check_expired(struct blk_mq_hw_ctx *hctx, |
652 | struct request *rq, void *priv, bool reserved) | |
653 | { | |
654 | struct blk_mq_timeout_data *data = priv; | |
87ee7b11 | 655 | |
eb130dbf KB |
656 | if (!test_bit(REQ_ATOM_STARTED, &rq->atomic_flags)) { |
657 | /* | |
658 | * If a request wasn't started before the queue was | |
659 | * marked dying, kill it here or it'll go unnoticed. | |
660 | */ | |
a59e0f57 KB |
661 | if (unlikely(blk_queue_dying(rq->q))) { |
662 | rq->errors = -EIO; | |
663 | blk_mq_end_request(rq, rq->errors); | |
664 | } | |
46f92d42 | 665 | return; |
eb130dbf | 666 | } |
87ee7b11 | 667 | |
46f92d42 CH |
668 | if (time_after_eq(jiffies, rq->deadline)) { |
669 | if (!blk_mark_rq_complete(rq)) | |
0152fb6b | 670 | blk_mq_rq_timed_out(rq, reserved); |
46f92d42 CH |
671 | } else if (!data->next_set || time_after(data->next, rq->deadline)) { |
672 | data->next = rq->deadline; | |
673 | data->next_set = 1; | |
674 | } | |
87ee7b11 JA |
675 | } |
676 | ||
287922eb | 677 | static void blk_mq_timeout_work(struct work_struct *work) |
320ae51f | 678 | { |
287922eb CH |
679 | struct request_queue *q = |
680 | container_of(work, struct request_queue, timeout_work); | |
81481eb4 CH |
681 | struct blk_mq_timeout_data data = { |
682 | .next = 0, | |
683 | .next_set = 0, | |
684 | }; | |
81481eb4 | 685 | int i; |
320ae51f | 686 | |
71f79fb3 GKB |
687 | /* A deadlock might occur if a request is stuck requiring a |
688 | * timeout at the same time a queue freeze is waiting | |
689 | * completion, since the timeout code would not be able to | |
690 | * acquire the queue reference here. | |
691 | * | |
692 | * That's why we don't use blk_queue_enter here; instead, we use | |
693 | * percpu_ref_tryget directly, because we need to be able to | |
694 | * obtain a reference even in the short window between the queue | |
695 | * starting to freeze, by dropping the first reference in | |
696 | * blk_mq_freeze_queue_start, and the moment the last request is | |
697 | * consumed, marked by the instant q_usage_counter reaches | |
698 | * zero. | |
699 | */ | |
700 | if (!percpu_ref_tryget(&q->q_usage_counter)) | |
287922eb CH |
701 | return; |
702 | ||
0bf6cd5b | 703 | blk_mq_queue_tag_busy_iter(q, blk_mq_check_expired, &data); |
320ae51f | 704 | |
81481eb4 CH |
705 | if (data.next_set) { |
706 | data.next = blk_rq_timeout(round_jiffies_up(data.next)); | |
707 | mod_timer(&q->timeout, data.next); | |
0d2602ca | 708 | } else { |
0bf6cd5b CH |
709 | struct blk_mq_hw_ctx *hctx; |
710 | ||
f054b56c ML |
711 | queue_for_each_hw_ctx(q, hctx, i) { |
712 | /* the hctx may be unmapped, so check it here */ | |
713 | if (blk_mq_hw_queue_mapped(hctx)) | |
714 | blk_mq_tag_idle(hctx); | |
715 | } | |
0d2602ca | 716 | } |
287922eb | 717 | blk_queue_exit(q); |
320ae51f JA |
718 | } |
719 | ||
720 | /* | |
721 | * Reverse check our software queue for entries that we could potentially | |
722 | * merge with. Currently includes a hand-wavy stop count of 8, to not spend | |
723 | * too much time checking for merges. | |
724 | */ | |
725 | static bool blk_mq_attempt_merge(struct request_queue *q, | |
726 | struct blk_mq_ctx *ctx, struct bio *bio) | |
727 | { | |
728 | struct request *rq; | |
729 | int checked = 8; | |
730 | ||
731 | list_for_each_entry_reverse(rq, &ctx->rq_list, queuelist) { | |
732 | int el_ret; | |
733 | ||
734 | if (!checked--) | |
735 | break; | |
736 | ||
737 | if (!blk_rq_merge_ok(rq, bio)) | |
738 | continue; | |
739 | ||
740 | el_ret = blk_try_merge(rq, bio); | |
741 | if (el_ret == ELEVATOR_BACK_MERGE) { | |
742 | if (bio_attempt_back_merge(q, rq, bio)) { | |
743 | ctx->rq_merged++; | |
744 | return true; | |
745 | } | |
746 | break; | |
747 | } else if (el_ret == ELEVATOR_FRONT_MERGE) { | |
748 | if (bio_attempt_front_merge(q, rq, bio)) { | |
749 | ctx->rq_merged++; | |
750 | return true; | |
751 | } | |
752 | break; | |
753 | } | |
754 | } | |
755 | ||
756 | return false; | |
757 | } | |
758 | ||
1429d7c9 JA |
759 | /* |
760 | * Process software queues that have been marked busy, splicing them | |
761 | * to the for-dispatch | |
762 | */ | |
763 | static void flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, struct list_head *list) | |
764 | { | |
765 | struct blk_mq_ctx *ctx; | |
766 | int i; | |
767 | ||
569fd0ce | 768 | for (i = 0; i < hctx->ctx_map.size; i++) { |
1429d7c9 JA |
769 | struct blk_align_bitmap *bm = &hctx->ctx_map.map[i]; |
770 | unsigned int off, bit; | |
771 | ||
772 | if (!bm->word) | |
773 | continue; | |
774 | ||
775 | bit = 0; | |
776 | off = i * hctx->ctx_map.bits_per_word; | |
777 | do { | |
778 | bit = find_next_bit(&bm->word, bm->depth, bit); | |
779 | if (bit >= bm->depth) | |
780 | break; | |
781 | ||
782 | ctx = hctx->ctxs[bit + off]; | |
783 | clear_bit(bit, &bm->word); | |
784 | spin_lock(&ctx->lock); | |
785 | list_splice_tail_init(&ctx->rq_list, list); | |
786 | spin_unlock(&ctx->lock); | |
787 | ||
788 | bit++; | |
789 | } while (1); | |
790 | } | |
791 | } | |
792 | ||
320ae51f JA |
793 | /* |
794 | * Run this hardware queue, pulling any software queues mapped to it in. | |
795 | * Note that this function currently has various problems around ordering | |
796 | * of IO. In particular, we'd like FIFO behaviour on handling existing | |
797 | * items on the hctx->dispatch list. Ignore that for now. | |
798 | */ | |
799 | static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx) | |
800 | { | |
801 | struct request_queue *q = hctx->queue; | |
320ae51f JA |
802 | struct request *rq; |
803 | LIST_HEAD(rq_list); | |
74c45052 JA |
804 | LIST_HEAD(driver_list); |
805 | struct list_head *dptr; | |
1429d7c9 | 806 | int queued; |
320ae51f | 807 | |
5d12f905 | 808 | if (unlikely(test_bit(BLK_MQ_S_STOPPED, &hctx->state))) |
320ae51f JA |
809 | return; |
810 | ||
0e87e58b JA |
811 | WARN_ON(!cpumask_test_cpu(raw_smp_processor_id(), hctx->cpumask) && |
812 | cpu_online(hctx->next_cpu)); | |
813 | ||
320ae51f JA |
814 | hctx->run++; |
815 | ||
816 | /* | |
817 | * Touch any software queue that has pending entries. | |
818 | */ | |
1429d7c9 | 819 | flush_busy_ctxs(hctx, &rq_list); |
320ae51f JA |
820 | |
821 | /* | |
822 | * If we have previous entries on our dispatch list, grab them | |
823 | * and stuff them at the front for more fair dispatch. | |
824 | */ | |
825 | if (!list_empty_careful(&hctx->dispatch)) { | |
826 | spin_lock(&hctx->lock); | |
827 | if (!list_empty(&hctx->dispatch)) | |
828 | list_splice_init(&hctx->dispatch, &rq_list); | |
829 | spin_unlock(&hctx->lock); | |
830 | } | |
831 | ||
74c45052 JA |
832 | /* |
833 | * Start off with dptr being NULL, so we start the first request | |
834 | * immediately, even if we have more pending. | |
835 | */ | |
836 | dptr = NULL; | |
837 | ||
320ae51f JA |
838 | /* |
839 | * Now process all the entries, sending them to the driver. | |
840 | */ | |
1429d7c9 | 841 | queued = 0; |
320ae51f | 842 | while (!list_empty(&rq_list)) { |
74c45052 | 843 | struct blk_mq_queue_data bd; |
320ae51f JA |
844 | int ret; |
845 | ||
846 | rq = list_first_entry(&rq_list, struct request, queuelist); | |
847 | list_del_init(&rq->queuelist); | |
320ae51f | 848 | |
74c45052 JA |
849 | bd.rq = rq; |
850 | bd.list = dptr; | |
851 | bd.last = list_empty(&rq_list); | |
852 | ||
853 | ret = q->mq_ops->queue_rq(hctx, &bd); | |
320ae51f JA |
854 | switch (ret) { |
855 | case BLK_MQ_RQ_QUEUE_OK: | |
856 | queued++; | |
52b9c330 | 857 | break; |
320ae51f | 858 | case BLK_MQ_RQ_QUEUE_BUSY: |
320ae51f | 859 | list_add(&rq->queuelist, &rq_list); |
ed0791b2 | 860 | __blk_mq_requeue_request(rq); |
320ae51f JA |
861 | break; |
862 | default: | |
863 | pr_err("blk-mq: bad return on queue: %d\n", ret); | |
320ae51f | 864 | case BLK_MQ_RQ_QUEUE_ERROR: |
1e93b8c2 | 865 | rq->errors = -EIO; |
c8a446ad | 866 | blk_mq_end_request(rq, rq->errors); |
320ae51f JA |
867 | break; |
868 | } | |
869 | ||
870 | if (ret == BLK_MQ_RQ_QUEUE_BUSY) | |
871 | break; | |
74c45052 JA |
872 | |
873 | /* | |
874 | * We've done the first request. If we have more than 1 | |
875 | * left in the list, set dptr to defer issue. | |
876 | */ | |
877 | if (!dptr && rq_list.next != rq_list.prev) | |
878 | dptr = &driver_list; | |
320ae51f JA |
879 | } |
880 | ||
881 | if (!queued) | |
882 | hctx->dispatched[0]++; | |
883 | else if (queued < (1 << (BLK_MQ_MAX_DISPATCH_ORDER - 1))) | |
884 | hctx->dispatched[ilog2(queued) + 1]++; | |
885 | ||
886 | /* | |
887 | * Any items that need requeuing? Stuff them into hctx->dispatch, | |
888 | * that is where we will continue on next queue run. | |
889 | */ | |
890 | if (!list_empty(&rq_list)) { | |
891 | spin_lock(&hctx->lock); | |
892 | list_splice(&rq_list, &hctx->dispatch); | |
893 | spin_unlock(&hctx->lock); | |
9ba52e58 SL |
894 | /* |
895 | * the queue is expected stopped with BLK_MQ_RQ_QUEUE_BUSY, but | |
896 | * it's possible the queue is stopped and restarted again | |
897 | * before this. Queue restart will dispatch requests. And since | |
898 | * requests in rq_list aren't added into hctx->dispatch yet, | |
899 | * the requests in rq_list might get lost. | |
900 | * | |
901 | * blk_mq_run_hw_queue() already checks the STOPPED bit | |
902 | **/ | |
903 | blk_mq_run_hw_queue(hctx, true); | |
320ae51f JA |
904 | } |
905 | } | |
906 | ||
506e931f JA |
907 | /* |
908 | * It'd be great if the workqueue API had a way to pass | |
909 | * in a mask and had some smarts for more clever placement. | |
910 | * For now we just round-robin here, switching for every | |
911 | * BLK_MQ_CPU_WORK_BATCH queued items. | |
912 | */ | |
913 | static int blk_mq_hctx_next_cpu(struct blk_mq_hw_ctx *hctx) | |
914 | { | |
b657d7e6 CH |
915 | if (hctx->queue->nr_hw_queues == 1) |
916 | return WORK_CPU_UNBOUND; | |
506e931f JA |
917 | |
918 | if (--hctx->next_cpu_batch <= 0) { | |
b657d7e6 | 919 | int cpu = hctx->next_cpu, next_cpu; |
506e931f JA |
920 | |
921 | next_cpu = cpumask_next(hctx->next_cpu, hctx->cpumask); | |
922 | if (next_cpu >= nr_cpu_ids) | |
923 | next_cpu = cpumask_first(hctx->cpumask); | |
924 | ||
925 | hctx->next_cpu = next_cpu; | |
926 | hctx->next_cpu_batch = BLK_MQ_CPU_WORK_BATCH; | |
b657d7e6 CH |
927 | |
928 | return cpu; | |
506e931f JA |
929 | } |
930 | ||
b657d7e6 | 931 | return hctx->next_cpu; |
506e931f JA |
932 | } |
933 | ||
320ae51f JA |
934 | void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async) |
935 | { | |
19c66e59 ML |
936 | if (unlikely(test_bit(BLK_MQ_S_STOPPED, &hctx->state) || |
937 | !blk_mq_hw_queue_mapped(hctx))) | |
320ae51f JA |
938 | return; |
939 | ||
398205b8 | 940 | if (!async) { |
2a90d4aa PB |
941 | int cpu = get_cpu(); |
942 | if (cpumask_test_cpu(cpu, hctx->cpumask)) { | |
398205b8 | 943 | __blk_mq_run_hw_queue(hctx); |
2a90d4aa | 944 | put_cpu(); |
398205b8 PB |
945 | return; |
946 | } | |
e4043dcf | 947 | |
2a90d4aa | 948 | put_cpu(); |
e4043dcf | 949 | } |
398205b8 | 950 | |
b657d7e6 CH |
951 | kblockd_schedule_delayed_work_on(blk_mq_hctx_next_cpu(hctx), |
952 | &hctx->run_work, 0); | |
320ae51f JA |
953 | } |
954 | ||
b94ec296 | 955 | void blk_mq_run_hw_queues(struct request_queue *q, bool async) |
320ae51f JA |
956 | { |
957 | struct blk_mq_hw_ctx *hctx; | |
958 | int i; | |
959 | ||
960 | queue_for_each_hw_ctx(q, hctx, i) { | |
961 | if ((!blk_mq_hctx_has_pending(hctx) && | |
962 | list_empty_careful(&hctx->dispatch)) || | |
5d12f905 | 963 | test_bit(BLK_MQ_S_STOPPED, &hctx->state)) |
320ae51f JA |
964 | continue; |
965 | ||
b94ec296 | 966 | blk_mq_run_hw_queue(hctx, async); |
320ae51f JA |
967 | } |
968 | } | |
b94ec296 | 969 | EXPORT_SYMBOL(blk_mq_run_hw_queues); |
320ae51f JA |
970 | |
971 | void blk_mq_stop_hw_queue(struct blk_mq_hw_ctx *hctx) | |
972 | { | |
70f4db63 CH |
973 | cancel_delayed_work(&hctx->run_work); |
974 | cancel_delayed_work(&hctx->delay_work); | |
320ae51f JA |
975 | set_bit(BLK_MQ_S_STOPPED, &hctx->state); |
976 | } | |
977 | EXPORT_SYMBOL(blk_mq_stop_hw_queue); | |
978 | ||
280d45f6 CH |
979 | void blk_mq_stop_hw_queues(struct request_queue *q) |
980 | { | |
981 | struct blk_mq_hw_ctx *hctx; | |
982 | int i; | |
983 | ||
984 | queue_for_each_hw_ctx(q, hctx, i) | |
985 | blk_mq_stop_hw_queue(hctx); | |
986 | } | |
987 | EXPORT_SYMBOL(blk_mq_stop_hw_queues); | |
988 | ||
320ae51f JA |
989 | void blk_mq_start_hw_queue(struct blk_mq_hw_ctx *hctx) |
990 | { | |
991 | clear_bit(BLK_MQ_S_STOPPED, &hctx->state); | |
e4043dcf | 992 | |
0ffbce80 | 993 | blk_mq_run_hw_queue(hctx, false); |
320ae51f JA |
994 | } |
995 | EXPORT_SYMBOL(blk_mq_start_hw_queue); | |
996 | ||
2f268556 CH |
997 | void blk_mq_start_hw_queues(struct request_queue *q) |
998 | { | |
999 | struct blk_mq_hw_ctx *hctx; | |
1000 | int i; | |
1001 | ||
1002 | queue_for_each_hw_ctx(q, hctx, i) | |
1003 | blk_mq_start_hw_queue(hctx); | |
1004 | } | |
1005 | EXPORT_SYMBOL(blk_mq_start_hw_queues); | |
1006 | ||
1b4a3258 | 1007 | void blk_mq_start_stopped_hw_queues(struct request_queue *q, bool async) |
320ae51f JA |
1008 | { |
1009 | struct blk_mq_hw_ctx *hctx; | |
1010 | int i; | |
1011 | ||
1012 | queue_for_each_hw_ctx(q, hctx, i) { | |
1013 | if (!test_bit(BLK_MQ_S_STOPPED, &hctx->state)) | |
1014 | continue; | |
1015 | ||
1016 | clear_bit(BLK_MQ_S_STOPPED, &hctx->state); | |
1b4a3258 | 1017 | blk_mq_run_hw_queue(hctx, async); |
320ae51f JA |
1018 | } |
1019 | } | |
1020 | EXPORT_SYMBOL(blk_mq_start_stopped_hw_queues); | |
1021 | ||
70f4db63 | 1022 | static void blk_mq_run_work_fn(struct work_struct *work) |
320ae51f JA |
1023 | { |
1024 | struct blk_mq_hw_ctx *hctx; | |
1025 | ||
70f4db63 | 1026 | hctx = container_of(work, struct blk_mq_hw_ctx, run_work.work); |
e4043dcf | 1027 | |
320ae51f JA |
1028 | __blk_mq_run_hw_queue(hctx); |
1029 | } | |
1030 | ||
70f4db63 CH |
1031 | static void blk_mq_delay_work_fn(struct work_struct *work) |
1032 | { | |
1033 | struct blk_mq_hw_ctx *hctx; | |
1034 | ||
1035 | hctx = container_of(work, struct blk_mq_hw_ctx, delay_work.work); | |
1036 | ||
1037 | if (test_and_clear_bit(BLK_MQ_S_STOPPED, &hctx->state)) | |
1038 | __blk_mq_run_hw_queue(hctx); | |
1039 | } | |
1040 | ||
1041 | void blk_mq_delay_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs) | |
1042 | { | |
19c66e59 ML |
1043 | if (unlikely(!blk_mq_hw_queue_mapped(hctx))) |
1044 | return; | |
70f4db63 | 1045 | |
b657d7e6 CH |
1046 | kblockd_schedule_delayed_work_on(blk_mq_hctx_next_cpu(hctx), |
1047 | &hctx->delay_work, msecs_to_jiffies(msecs)); | |
70f4db63 CH |
1048 | } |
1049 | EXPORT_SYMBOL(blk_mq_delay_queue); | |
1050 | ||
cfd0c552 | 1051 | static inline void __blk_mq_insert_req_list(struct blk_mq_hw_ctx *hctx, |
cfd0c552 ML |
1052 | struct request *rq, |
1053 | bool at_head) | |
320ae51f | 1054 | { |
e57690fe JA |
1055 | struct blk_mq_ctx *ctx = rq->mq_ctx; |
1056 | ||
01b983c9 JA |
1057 | trace_block_rq_insert(hctx->queue, rq); |
1058 | ||
72a0a36e CH |
1059 | if (at_head) |
1060 | list_add(&rq->queuelist, &ctx->rq_list); | |
1061 | else | |
1062 | list_add_tail(&rq->queuelist, &ctx->rq_list); | |
cfd0c552 | 1063 | } |
4bb659b1 | 1064 | |
cfd0c552 ML |
1065 | static void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, |
1066 | struct request *rq, bool at_head) | |
1067 | { | |
1068 | struct blk_mq_ctx *ctx = rq->mq_ctx; | |
1069 | ||
e57690fe | 1070 | __blk_mq_insert_req_list(hctx, rq, at_head); |
320ae51f | 1071 | blk_mq_hctx_mark_pending(hctx, ctx); |
320ae51f JA |
1072 | } |
1073 | ||
eeabc850 | 1074 | void blk_mq_insert_request(struct request *rq, bool at_head, bool run_queue, |
e57690fe | 1075 | bool async) |
320ae51f | 1076 | { |
e57690fe | 1077 | struct blk_mq_ctx *ctx = rq->mq_ctx; |
eeabc850 | 1078 | struct request_queue *q = rq->q; |
320ae51f | 1079 | struct blk_mq_hw_ctx *hctx; |
320ae51f | 1080 | |
320ae51f JA |
1081 | hctx = q->mq_ops->map_queue(q, ctx->cpu); |
1082 | ||
a57a178a CH |
1083 | spin_lock(&ctx->lock); |
1084 | __blk_mq_insert_request(hctx, rq, at_head); | |
1085 | spin_unlock(&ctx->lock); | |
320ae51f | 1086 | |
320ae51f JA |
1087 | if (run_queue) |
1088 | blk_mq_run_hw_queue(hctx, async); | |
1089 | } | |
1090 | ||
1091 | static void blk_mq_insert_requests(struct request_queue *q, | |
1092 | struct blk_mq_ctx *ctx, | |
1093 | struct list_head *list, | |
1094 | int depth, | |
1095 | bool from_schedule) | |
1096 | ||
1097 | { | |
1098 | struct blk_mq_hw_ctx *hctx; | |
320ae51f JA |
1099 | |
1100 | trace_block_unplug(q, depth, !from_schedule); | |
1101 | ||
320ae51f JA |
1102 | hctx = q->mq_ops->map_queue(q, ctx->cpu); |
1103 | ||
1104 | /* | |
1105 | * preemption doesn't flush plug list, so it's possible ctx->cpu is | |
1106 | * offline now | |
1107 | */ | |
1108 | spin_lock(&ctx->lock); | |
1109 | while (!list_empty(list)) { | |
1110 | struct request *rq; | |
1111 | ||
1112 | rq = list_first_entry(list, struct request, queuelist); | |
e57690fe | 1113 | BUG_ON(rq->mq_ctx != ctx); |
320ae51f | 1114 | list_del_init(&rq->queuelist); |
e57690fe | 1115 | __blk_mq_insert_req_list(hctx, rq, false); |
320ae51f | 1116 | } |
cfd0c552 | 1117 | blk_mq_hctx_mark_pending(hctx, ctx); |
320ae51f JA |
1118 | spin_unlock(&ctx->lock); |
1119 | ||
320ae51f JA |
1120 | blk_mq_run_hw_queue(hctx, from_schedule); |
1121 | } | |
1122 | ||
1123 | static int plug_ctx_cmp(void *priv, struct list_head *a, struct list_head *b) | |
1124 | { | |
1125 | struct request *rqa = container_of(a, struct request, queuelist); | |
1126 | struct request *rqb = container_of(b, struct request, queuelist); | |
1127 | ||
1128 | return !(rqa->mq_ctx < rqb->mq_ctx || | |
1129 | (rqa->mq_ctx == rqb->mq_ctx && | |
1130 | blk_rq_pos(rqa) < blk_rq_pos(rqb))); | |
1131 | } | |
1132 | ||
1133 | void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule) | |
1134 | { | |
1135 | struct blk_mq_ctx *this_ctx; | |
1136 | struct request_queue *this_q; | |
1137 | struct request *rq; | |
1138 | LIST_HEAD(list); | |
1139 | LIST_HEAD(ctx_list); | |
1140 | unsigned int depth; | |
1141 | ||
1142 | list_splice_init(&plug->mq_list, &list); | |
1143 | ||
1144 | list_sort(NULL, &list, plug_ctx_cmp); | |
1145 | ||
1146 | this_q = NULL; | |
1147 | this_ctx = NULL; | |
1148 | depth = 0; | |
1149 | ||
1150 | while (!list_empty(&list)) { | |
1151 | rq = list_entry_rq(list.next); | |
1152 | list_del_init(&rq->queuelist); | |
1153 | BUG_ON(!rq->q); | |
1154 | if (rq->mq_ctx != this_ctx) { | |
1155 | if (this_ctx) { | |
1156 | blk_mq_insert_requests(this_q, this_ctx, | |
1157 | &ctx_list, depth, | |
1158 | from_schedule); | |
1159 | } | |
1160 | ||
1161 | this_ctx = rq->mq_ctx; | |
1162 | this_q = rq->q; | |
1163 | depth = 0; | |
1164 | } | |
1165 | ||
1166 | depth++; | |
1167 | list_add_tail(&rq->queuelist, &ctx_list); | |
1168 | } | |
1169 | ||
1170 | /* | |
1171 | * If 'this_ctx' is set, we know we have entries to complete | |
1172 | * on 'ctx_list'. Do those. | |
1173 | */ | |
1174 | if (this_ctx) { | |
1175 | blk_mq_insert_requests(this_q, this_ctx, &ctx_list, depth, | |
1176 | from_schedule); | |
1177 | } | |
1178 | } | |
1179 | ||
1180 | static void blk_mq_bio_to_request(struct request *rq, struct bio *bio) | |
1181 | { | |
1182 | init_request_from_bio(rq, bio); | |
4b570521 | 1183 | |
a21f2a3e | 1184 | blk_account_io_start(rq, 1); |
320ae51f JA |
1185 | } |
1186 | ||
274a5843 JA |
1187 | static inline bool hctx_allow_merges(struct blk_mq_hw_ctx *hctx) |
1188 | { | |
1189 | return (hctx->flags & BLK_MQ_F_SHOULD_MERGE) && | |
1190 | !blk_queue_nomerges(hctx->queue); | |
1191 | } | |
1192 | ||
07068d5b JA |
1193 | static inline bool blk_mq_merge_queue_io(struct blk_mq_hw_ctx *hctx, |
1194 | struct blk_mq_ctx *ctx, | |
1195 | struct request *rq, struct bio *bio) | |
320ae51f | 1196 | { |
e18378a6 | 1197 | if (!hctx_allow_merges(hctx) || !bio_mergeable(bio)) { |
07068d5b JA |
1198 | blk_mq_bio_to_request(rq, bio); |
1199 | spin_lock(&ctx->lock); | |
1200 | insert_rq: | |
1201 | __blk_mq_insert_request(hctx, rq, false); | |
1202 | spin_unlock(&ctx->lock); | |
1203 | return false; | |
1204 | } else { | |
274a5843 JA |
1205 | struct request_queue *q = hctx->queue; |
1206 | ||
07068d5b JA |
1207 | spin_lock(&ctx->lock); |
1208 | if (!blk_mq_attempt_merge(q, ctx, bio)) { | |
1209 | blk_mq_bio_to_request(rq, bio); | |
1210 | goto insert_rq; | |
1211 | } | |
320ae51f | 1212 | |
07068d5b JA |
1213 | spin_unlock(&ctx->lock); |
1214 | __blk_mq_free_request(hctx, ctx, rq); | |
1215 | return true; | |
14ec77f3 | 1216 | } |
07068d5b | 1217 | } |
14ec77f3 | 1218 | |
07068d5b JA |
1219 | struct blk_map_ctx { |
1220 | struct blk_mq_hw_ctx *hctx; | |
1221 | struct blk_mq_ctx *ctx; | |
1222 | }; | |
1223 | ||
1224 | static struct request *blk_mq_map_request(struct request_queue *q, | |
1225 | struct bio *bio, | |
1226 | struct blk_map_ctx *data) | |
1227 | { | |
1228 | struct blk_mq_hw_ctx *hctx; | |
1229 | struct blk_mq_ctx *ctx; | |
1230 | struct request *rq; | |
cc6e3b10 MC |
1231 | int op = bio_data_dir(bio); |
1232 | int op_flags = 0; | |
cb96a42c | 1233 | struct blk_mq_alloc_data alloc_data; |
320ae51f | 1234 | |
3ef28e83 | 1235 | blk_queue_enter_live(q); |
320ae51f JA |
1236 | ctx = blk_mq_get_ctx(q); |
1237 | hctx = q->mq_ops->map_queue(q, ctx->cpu); | |
1238 | ||
1eff9d32 | 1239 | if (rw_is_sync(bio_op(bio), bio->bi_opf)) |
cc6e3b10 | 1240 | op_flags |= REQ_SYNC; |
07068d5b | 1241 | |
cc6e3b10 | 1242 | trace_block_getrq(q, bio, op); |
6f3b0e8b | 1243 | blk_mq_set_alloc_data(&alloc_data, q, BLK_MQ_REQ_NOWAIT, ctx, hctx); |
cc6e3b10 | 1244 | rq = __blk_mq_alloc_request(&alloc_data, op, op_flags); |
5dee8577 | 1245 | if (unlikely(!rq)) { |
793597a6 | 1246 | __blk_mq_run_hw_queue(hctx); |
320ae51f | 1247 | blk_mq_put_ctx(ctx); |
cc6e3b10 | 1248 | trace_block_sleeprq(q, bio, op); |
793597a6 CH |
1249 | |
1250 | ctx = blk_mq_get_ctx(q); | |
320ae51f | 1251 | hctx = q->mq_ops->map_queue(q, ctx->cpu); |
6f3b0e8b | 1252 | blk_mq_set_alloc_data(&alloc_data, q, 0, ctx, hctx); |
cc6e3b10 | 1253 | rq = __blk_mq_alloc_request(&alloc_data, op, op_flags); |
cb96a42c ML |
1254 | ctx = alloc_data.ctx; |
1255 | hctx = alloc_data.hctx; | |
320ae51f JA |
1256 | } |
1257 | ||
1258 | hctx->queued++; | |
07068d5b JA |
1259 | data->hctx = hctx; |
1260 | data->ctx = ctx; | |
1261 | return rq; | |
1262 | } | |
1263 | ||
7b371636 | 1264 | static int blk_mq_direct_issue_request(struct request *rq, blk_qc_t *cookie) |
f984df1f SL |
1265 | { |
1266 | int ret; | |
1267 | struct request_queue *q = rq->q; | |
1268 | struct blk_mq_hw_ctx *hctx = q->mq_ops->map_queue(q, | |
1269 | rq->mq_ctx->cpu); | |
1270 | struct blk_mq_queue_data bd = { | |
1271 | .rq = rq, | |
1272 | .list = NULL, | |
1273 | .last = 1 | |
1274 | }; | |
7b371636 | 1275 | blk_qc_t new_cookie = blk_tag_to_qc_t(rq->tag, hctx->queue_num); |
f984df1f SL |
1276 | |
1277 | /* | |
1278 | * For OK queue, we are done. For error, kill it. Any other | |
1279 | * error (busy), just add it to our list as we previously | |
1280 | * would have done | |
1281 | */ | |
1282 | ret = q->mq_ops->queue_rq(hctx, &bd); | |
7b371636 JA |
1283 | if (ret == BLK_MQ_RQ_QUEUE_OK) { |
1284 | *cookie = new_cookie; | |
f984df1f | 1285 | return 0; |
7b371636 | 1286 | } |
f984df1f | 1287 | |
7b371636 JA |
1288 | __blk_mq_requeue_request(rq); |
1289 | ||
1290 | if (ret == BLK_MQ_RQ_QUEUE_ERROR) { | |
1291 | *cookie = BLK_QC_T_NONE; | |
1292 | rq->errors = -EIO; | |
1293 | blk_mq_end_request(rq, rq->errors); | |
1294 | return 0; | |
f984df1f | 1295 | } |
7b371636 JA |
1296 | |
1297 | return -1; | |
f984df1f SL |
1298 | } |
1299 | ||
07068d5b JA |
1300 | /* |
1301 | * Multiple hardware queue variant. This will not use per-process plugs, | |
1302 | * but will attempt to bypass the hctx queueing if we can go straight to | |
1303 | * hardware for SYNC IO. | |
1304 | */ | |
dece1635 | 1305 | static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio) |
07068d5b | 1306 | { |
1eff9d32 JA |
1307 | const int is_sync = rw_is_sync(bio_op(bio), bio->bi_opf); |
1308 | const int is_flush_fua = bio->bi_opf & (REQ_PREFLUSH | REQ_FUA); | |
07068d5b JA |
1309 | struct blk_map_ctx data; |
1310 | struct request *rq; | |
f984df1f SL |
1311 | unsigned int request_count = 0; |
1312 | struct blk_plug *plug; | |
5b3f341f | 1313 | struct request *same_queue_rq = NULL; |
7b371636 | 1314 | blk_qc_t cookie; |
07068d5b JA |
1315 | |
1316 | blk_queue_bounce(q, &bio); | |
1317 | ||
1318 | if (bio_integrity_enabled(bio) && bio_integrity_prep(bio)) { | |
4246a0b6 | 1319 | bio_io_error(bio); |
dece1635 | 1320 | return BLK_QC_T_NONE; |
07068d5b JA |
1321 | } |
1322 | ||
54efd50b KO |
1323 | blk_queue_split(q, &bio, q->bio_split); |
1324 | ||
87c279e6 OS |
1325 | if (!is_flush_fua && !blk_queue_nomerges(q) && |
1326 | blk_attempt_plug_merge(q, bio, &request_count, &same_queue_rq)) | |
1327 | return BLK_QC_T_NONE; | |
f984df1f | 1328 | |
07068d5b JA |
1329 | rq = blk_mq_map_request(q, bio, &data); |
1330 | if (unlikely(!rq)) | |
dece1635 | 1331 | return BLK_QC_T_NONE; |
07068d5b | 1332 | |
7b371636 | 1333 | cookie = blk_tag_to_qc_t(rq->tag, data.hctx->queue_num); |
07068d5b JA |
1334 | |
1335 | if (unlikely(is_flush_fua)) { | |
1336 | blk_mq_bio_to_request(rq, bio); | |
1337 | blk_insert_flush(rq); | |
1338 | goto run_queue; | |
1339 | } | |
1340 | ||
f984df1f | 1341 | plug = current->plug; |
e167dfb5 JA |
1342 | /* |
1343 | * If the driver supports defer issued based on 'last', then | |
1344 | * queue it up like normal since we can potentially save some | |
1345 | * CPU this way. | |
1346 | */ | |
f984df1f SL |
1347 | if (((plug && !blk_queue_nomerges(q)) || is_sync) && |
1348 | !(data.hctx->flags & BLK_MQ_F_DEFER_ISSUE)) { | |
1349 | struct request *old_rq = NULL; | |
07068d5b JA |
1350 | |
1351 | blk_mq_bio_to_request(rq, bio); | |
07068d5b JA |
1352 | |
1353 | /* | |
b094f89c | 1354 | * We do limited pluging. If the bio can be merged, do that. |
f984df1f SL |
1355 | * Otherwise the existing request in the plug list will be |
1356 | * issued. So the plug list will have one request at most | |
07068d5b | 1357 | */ |
f984df1f | 1358 | if (plug) { |
5b3f341f SL |
1359 | /* |
1360 | * The plug list might get flushed before this. If that | |
b094f89c JA |
1361 | * happens, same_queue_rq is invalid and plug list is |
1362 | * empty | |
1363 | */ | |
5b3f341f SL |
1364 | if (same_queue_rq && !list_empty(&plug->mq_list)) { |
1365 | old_rq = same_queue_rq; | |
f984df1f | 1366 | list_del_init(&old_rq->queuelist); |
07068d5b | 1367 | } |
f984df1f SL |
1368 | list_add_tail(&rq->queuelist, &plug->mq_list); |
1369 | } else /* is_sync */ | |
1370 | old_rq = rq; | |
1371 | blk_mq_put_ctx(data.ctx); | |
1372 | if (!old_rq) | |
7b371636 JA |
1373 | goto done; |
1374 | if (!blk_mq_direct_issue_request(old_rq, &cookie)) | |
1375 | goto done; | |
f984df1f | 1376 | blk_mq_insert_request(old_rq, false, true, true); |
7b371636 | 1377 | goto done; |
07068d5b JA |
1378 | } |
1379 | ||
1380 | if (!blk_mq_merge_queue_io(data.hctx, data.ctx, rq, bio)) { | |
1381 | /* | |
1382 | * For a SYNC request, send it to the hardware immediately. For | |
1383 | * an ASYNC request, just ensure that we run it later on. The | |
1384 | * latter allows for merging opportunities and more efficient | |
1385 | * dispatching. | |
1386 | */ | |
1387 | run_queue: | |
1388 | blk_mq_run_hw_queue(data.hctx, !is_sync || is_flush_fua); | |
1389 | } | |
07068d5b | 1390 | blk_mq_put_ctx(data.ctx); |
7b371636 JA |
1391 | done: |
1392 | return cookie; | |
07068d5b JA |
1393 | } |
1394 | ||
1395 | /* | |
1396 | * Single hardware queue variant. This will attempt to use any per-process | |
1397 | * plug for merging and IO deferral. | |
1398 | */ | |
dece1635 | 1399 | static blk_qc_t blk_sq_make_request(struct request_queue *q, struct bio *bio) |
07068d5b | 1400 | { |
1eff9d32 JA |
1401 | const int is_sync = rw_is_sync(bio_op(bio), bio->bi_opf); |
1402 | const int is_flush_fua = bio->bi_opf & (REQ_PREFLUSH | REQ_FUA); | |
e6c4438b JM |
1403 | struct blk_plug *plug; |
1404 | unsigned int request_count = 0; | |
07068d5b JA |
1405 | struct blk_map_ctx data; |
1406 | struct request *rq; | |
7b371636 | 1407 | blk_qc_t cookie; |
07068d5b | 1408 | |
07068d5b JA |
1409 | blk_queue_bounce(q, &bio); |
1410 | ||
1411 | if (bio_integrity_enabled(bio) && bio_integrity_prep(bio)) { | |
4246a0b6 | 1412 | bio_io_error(bio); |
dece1635 | 1413 | return BLK_QC_T_NONE; |
07068d5b JA |
1414 | } |
1415 | ||
54efd50b KO |
1416 | blk_queue_split(q, &bio, q->bio_split); |
1417 | ||
87c279e6 OS |
1418 | if (!is_flush_fua && !blk_queue_nomerges(q)) { |
1419 | if (blk_attempt_plug_merge(q, bio, &request_count, NULL)) | |
1420 | return BLK_QC_T_NONE; | |
1421 | } else | |
1422 | request_count = blk_plug_queued_count(q); | |
07068d5b JA |
1423 | |
1424 | rq = blk_mq_map_request(q, bio, &data); | |
ff87bcec | 1425 | if (unlikely(!rq)) |
dece1635 | 1426 | return BLK_QC_T_NONE; |
320ae51f | 1427 | |
7b371636 | 1428 | cookie = blk_tag_to_qc_t(rq->tag, data.hctx->queue_num); |
320ae51f JA |
1429 | |
1430 | if (unlikely(is_flush_fua)) { | |
1431 | blk_mq_bio_to_request(rq, bio); | |
320ae51f JA |
1432 | blk_insert_flush(rq); |
1433 | goto run_queue; | |
1434 | } | |
1435 | ||
1436 | /* | |
1437 | * A task plug currently exists. Since this is completely lockless, | |
1438 | * utilize that to temporarily store requests until the task is | |
1439 | * either done or scheduled away. | |
1440 | */ | |
e6c4438b JM |
1441 | plug = current->plug; |
1442 | if (plug) { | |
1443 | blk_mq_bio_to_request(rq, bio); | |
676d0607 | 1444 | if (!request_count) |
e6c4438b | 1445 | trace_block_plug(q); |
b094f89c JA |
1446 | |
1447 | blk_mq_put_ctx(data.ctx); | |
1448 | ||
1449 | if (request_count >= BLK_MAX_REQUEST_COUNT) { | |
e6c4438b JM |
1450 | blk_flush_plug_list(plug, false); |
1451 | trace_block_plug(q); | |
320ae51f | 1452 | } |
b094f89c | 1453 | |
e6c4438b | 1454 | list_add_tail(&rq->queuelist, &plug->mq_list); |
7b371636 | 1455 | return cookie; |
320ae51f JA |
1456 | } |
1457 | ||
07068d5b JA |
1458 | if (!blk_mq_merge_queue_io(data.hctx, data.ctx, rq, bio)) { |
1459 | /* | |
1460 | * For a SYNC request, send it to the hardware immediately. For | |
1461 | * an ASYNC request, just ensure that we run it later on. The | |
1462 | * latter allows for merging opportunities and more efficient | |
1463 | * dispatching. | |
1464 | */ | |
1465 | run_queue: | |
1466 | blk_mq_run_hw_queue(data.hctx, !is_sync || is_flush_fua); | |
320ae51f JA |
1467 | } |
1468 | ||
07068d5b | 1469 | blk_mq_put_ctx(data.ctx); |
7b371636 | 1470 | return cookie; |
320ae51f JA |
1471 | } |
1472 | ||
1473 | /* | |
1474 | * Default mapping to a software queue, since we use one per CPU. | |
1475 | */ | |
1476 | struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q, const int cpu) | |
1477 | { | |
1478 | return q->queue_hw_ctx[q->mq_map[cpu]]; | |
1479 | } | |
1480 | EXPORT_SYMBOL(blk_mq_map_queue); | |
1481 | ||
24d2f903 CH |
1482 | static void blk_mq_free_rq_map(struct blk_mq_tag_set *set, |
1483 | struct blk_mq_tags *tags, unsigned int hctx_idx) | |
95363efd | 1484 | { |
e9b267d9 | 1485 | struct page *page; |
320ae51f | 1486 | |
24d2f903 | 1487 | if (tags->rqs && set->ops->exit_request) { |
e9b267d9 | 1488 | int i; |
320ae51f | 1489 | |
24d2f903 CH |
1490 | for (i = 0; i < tags->nr_tags; i++) { |
1491 | if (!tags->rqs[i]) | |
e9b267d9 | 1492 | continue; |
24d2f903 CH |
1493 | set->ops->exit_request(set->driver_data, tags->rqs[i], |
1494 | hctx_idx, i); | |
a5164405 | 1495 | tags->rqs[i] = NULL; |
e9b267d9 | 1496 | } |
320ae51f | 1497 | } |
320ae51f | 1498 | |
24d2f903 CH |
1499 | while (!list_empty(&tags->page_list)) { |
1500 | page = list_first_entry(&tags->page_list, struct page, lru); | |
6753471c | 1501 | list_del_init(&page->lru); |
f75782e4 CM |
1502 | /* |
1503 | * Remove kmemleak object previously allocated in | |
1504 | * blk_mq_init_rq_map(). | |
1505 | */ | |
1506 | kmemleak_free(page_address(page)); | |
320ae51f JA |
1507 | __free_pages(page, page->private); |
1508 | } | |
1509 | ||
24d2f903 | 1510 | kfree(tags->rqs); |
320ae51f | 1511 | |
24d2f903 | 1512 | blk_mq_free_tags(tags); |
320ae51f JA |
1513 | } |
1514 | ||
1515 | static size_t order_to_size(unsigned int order) | |
1516 | { | |
4ca08500 | 1517 | return (size_t)PAGE_SIZE << order; |
320ae51f JA |
1518 | } |
1519 | ||
24d2f903 CH |
1520 | static struct blk_mq_tags *blk_mq_init_rq_map(struct blk_mq_tag_set *set, |
1521 | unsigned int hctx_idx) | |
320ae51f | 1522 | { |
24d2f903 | 1523 | struct blk_mq_tags *tags; |
320ae51f JA |
1524 | unsigned int i, j, entries_per_page, max_order = 4; |
1525 | size_t rq_size, left; | |
1526 | ||
24d2f903 | 1527 | tags = blk_mq_init_tags(set->queue_depth, set->reserved_tags, |
24391c0d SL |
1528 | set->numa_node, |
1529 | BLK_MQ_FLAG_TO_ALLOC_POLICY(set->flags)); | |
24d2f903 CH |
1530 | if (!tags) |
1531 | return NULL; | |
320ae51f | 1532 | |
24d2f903 CH |
1533 | INIT_LIST_HEAD(&tags->page_list); |
1534 | ||
a5164405 JA |
1535 | tags->rqs = kzalloc_node(set->queue_depth * sizeof(struct request *), |
1536 | GFP_KERNEL | __GFP_NOWARN | __GFP_NORETRY, | |
1537 | set->numa_node); | |
24d2f903 CH |
1538 | if (!tags->rqs) { |
1539 | blk_mq_free_tags(tags); | |
1540 | return NULL; | |
1541 | } | |
320ae51f JA |
1542 | |
1543 | /* | |
1544 | * rq_size is the size of the request plus driver payload, rounded | |
1545 | * to the cacheline size | |
1546 | */ | |
24d2f903 | 1547 | rq_size = round_up(sizeof(struct request) + set->cmd_size, |
320ae51f | 1548 | cache_line_size()); |
24d2f903 | 1549 | left = rq_size * set->queue_depth; |
320ae51f | 1550 | |
24d2f903 | 1551 | for (i = 0; i < set->queue_depth; ) { |
320ae51f JA |
1552 | int this_order = max_order; |
1553 | struct page *page; | |
1554 | int to_do; | |
1555 | void *p; | |
1556 | ||
b3a834b1 | 1557 | while (this_order && left < order_to_size(this_order - 1)) |
320ae51f JA |
1558 | this_order--; |
1559 | ||
1560 | do { | |
a5164405 | 1561 | page = alloc_pages_node(set->numa_node, |
ac211175 | 1562 | GFP_KERNEL | __GFP_NOWARN | __GFP_NORETRY | __GFP_ZERO, |
a5164405 | 1563 | this_order); |
320ae51f JA |
1564 | if (page) |
1565 | break; | |
1566 | if (!this_order--) | |
1567 | break; | |
1568 | if (order_to_size(this_order) < rq_size) | |
1569 | break; | |
1570 | } while (1); | |
1571 | ||
1572 | if (!page) | |
24d2f903 | 1573 | goto fail; |
320ae51f JA |
1574 | |
1575 | page->private = this_order; | |
24d2f903 | 1576 | list_add_tail(&page->lru, &tags->page_list); |
320ae51f JA |
1577 | |
1578 | p = page_address(page); | |
f75782e4 CM |
1579 | /* |
1580 | * Allow kmemleak to scan these pages as they contain pointers | |
1581 | * to additional allocations like via ops->init_request(). | |
1582 | */ | |
1583 | kmemleak_alloc(p, order_to_size(this_order), 1, GFP_KERNEL); | |
320ae51f | 1584 | entries_per_page = order_to_size(this_order) / rq_size; |
24d2f903 | 1585 | to_do = min(entries_per_page, set->queue_depth - i); |
320ae51f JA |
1586 | left -= to_do * rq_size; |
1587 | for (j = 0; j < to_do; j++) { | |
24d2f903 CH |
1588 | tags->rqs[i] = p; |
1589 | if (set->ops->init_request) { | |
1590 | if (set->ops->init_request(set->driver_data, | |
1591 | tags->rqs[i], hctx_idx, i, | |
a5164405 JA |
1592 | set->numa_node)) { |
1593 | tags->rqs[i] = NULL; | |
24d2f903 | 1594 | goto fail; |
a5164405 | 1595 | } |
e9b267d9 CH |
1596 | } |
1597 | ||
320ae51f JA |
1598 | p += rq_size; |
1599 | i++; | |
1600 | } | |
1601 | } | |
24d2f903 | 1602 | return tags; |
320ae51f | 1603 | |
24d2f903 | 1604 | fail: |
24d2f903 CH |
1605 | blk_mq_free_rq_map(set, tags, hctx_idx); |
1606 | return NULL; | |
320ae51f JA |
1607 | } |
1608 | ||
1429d7c9 JA |
1609 | static void blk_mq_free_bitmap(struct blk_mq_ctxmap *bitmap) |
1610 | { | |
1611 | kfree(bitmap->map); | |
1612 | } | |
1613 | ||
1614 | static int blk_mq_alloc_bitmap(struct blk_mq_ctxmap *bitmap, int node) | |
1615 | { | |
1616 | unsigned int bpw = 8, total, num_maps, i; | |
1617 | ||
1618 | bitmap->bits_per_word = bpw; | |
1619 | ||
1620 | num_maps = ALIGN(nr_cpu_ids, bpw) / bpw; | |
1621 | bitmap->map = kzalloc_node(num_maps * sizeof(struct blk_align_bitmap), | |
1622 | GFP_KERNEL, node); | |
1623 | if (!bitmap->map) | |
1624 | return -ENOMEM; | |
1625 | ||
1429d7c9 JA |
1626 | total = nr_cpu_ids; |
1627 | for (i = 0; i < num_maps; i++) { | |
1628 | bitmap->map[i].depth = min(total, bitmap->bits_per_word); | |
1629 | total -= bitmap->map[i].depth; | |
1630 | } | |
1631 | ||
1632 | return 0; | |
1633 | } | |
1634 | ||
e57690fe JA |
1635 | /* |
1636 | * 'cpu' is going away. splice any existing rq_list entries from this | |
1637 | * software queue to the hw queue dispatch list, and ensure that it | |
1638 | * gets run. | |
1639 | */ | |
484b4061 JA |
1640 | static int blk_mq_hctx_cpu_offline(struct blk_mq_hw_ctx *hctx, int cpu) |
1641 | { | |
484b4061 JA |
1642 | struct blk_mq_ctx *ctx; |
1643 | LIST_HEAD(tmp); | |
1644 | ||
e57690fe | 1645 | ctx = __blk_mq_get_ctx(hctx->queue, cpu); |
484b4061 JA |
1646 | |
1647 | spin_lock(&ctx->lock); | |
1648 | if (!list_empty(&ctx->rq_list)) { | |
1649 | list_splice_init(&ctx->rq_list, &tmp); | |
1650 | blk_mq_hctx_clear_pending(hctx, ctx); | |
1651 | } | |
1652 | spin_unlock(&ctx->lock); | |
1653 | ||
1654 | if (list_empty(&tmp)) | |
1655 | return NOTIFY_OK; | |
1656 | ||
e57690fe JA |
1657 | spin_lock(&hctx->lock); |
1658 | list_splice_tail_init(&tmp, &hctx->dispatch); | |
1659 | spin_unlock(&hctx->lock); | |
484b4061 JA |
1660 | |
1661 | blk_mq_run_hw_queue(hctx, true); | |
484b4061 JA |
1662 | return NOTIFY_OK; |
1663 | } | |
1664 | ||
484b4061 JA |
1665 | static int blk_mq_hctx_notify(void *data, unsigned long action, |
1666 | unsigned int cpu) | |
1667 | { | |
1668 | struct blk_mq_hw_ctx *hctx = data; | |
1669 | ||
1670 | if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) | |
1671 | return blk_mq_hctx_cpu_offline(hctx, cpu); | |
2a34c087 ML |
1672 | |
1673 | /* | |
1674 | * In case of CPU online, tags may be reallocated | |
1675 | * in blk_mq_map_swqueue() after mapping is updated. | |
1676 | */ | |
484b4061 JA |
1677 | |
1678 | return NOTIFY_OK; | |
1679 | } | |
1680 | ||
c3b4afca | 1681 | /* hctx->ctxs will be freed in queue's release handler */ |
08e98fc6 ML |
1682 | static void blk_mq_exit_hctx(struct request_queue *q, |
1683 | struct blk_mq_tag_set *set, | |
1684 | struct blk_mq_hw_ctx *hctx, unsigned int hctx_idx) | |
1685 | { | |
f70ced09 ML |
1686 | unsigned flush_start_tag = set->queue_depth; |
1687 | ||
08e98fc6 ML |
1688 | blk_mq_tag_idle(hctx); |
1689 | ||
f70ced09 ML |
1690 | if (set->ops->exit_request) |
1691 | set->ops->exit_request(set->driver_data, | |
1692 | hctx->fq->flush_rq, hctx_idx, | |
1693 | flush_start_tag + hctx_idx); | |
1694 | ||
08e98fc6 ML |
1695 | if (set->ops->exit_hctx) |
1696 | set->ops->exit_hctx(hctx, hctx_idx); | |
1697 | ||
1698 | blk_mq_unregister_cpu_notifier(&hctx->cpu_notifier); | |
f70ced09 | 1699 | blk_free_flush_queue(hctx->fq); |
08e98fc6 ML |
1700 | blk_mq_free_bitmap(&hctx->ctx_map); |
1701 | } | |
1702 | ||
624dbe47 ML |
1703 | static void blk_mq_exit_hw_queues(struct request_queue *q, |
1704 | struct blk_mq_tag_set *set, int nr_queue) | |
1705 | { | |
1706 | struct blk_mq_hw_ctx *hctx; | |
1707 | unsigned int i; | |
1708 | ||
1709 | queue_for_each_hw_ctx(q, hctx, i) { | |
1710 | if (i == nr_queue) | |
1711 | break; | |
08e98fc6 | 1712 | blk_mq_exit_hctx(q, set, hctx, i); |
624dbe47 | 1713 | } |
624dbe47 ML |
1714 | } |
1715 | ||
1716 | static void blk_mq_free_hw_queues(struct request_queue *q, | |
1717 | struct blk_mq_tag_set *set) | |
1718 | { | |
1719 | struct blk_mq_hw_ctx *hctx; | |
1720 | unsigned int i; | |
1721 | ||
e09aae7e | 1722 | queue_for_each_hw_ctx(q, hctx, i) |
624dbe47 | 1723 | free_cpumask_var(hctx->cpumask); |
624dbe47 ML |
1724 | } |
1725 | ||
08e98fc6 ML |
1726 | static int blk_mq_init_hctx(struct request_queue *q, |
1727 | struct blk_mq_tag_set *set, | |
1728 | struct blk_mq_hw_ctx *hctx, unsigned hctx_idx) | |
320ae51f | 1729 | { |
08e98fc6 | 1730 | int node; |
f70ced09 | 1731 | unsigned flush_start_tag = set->queue_depth; |
08e98fc6 ML |
1732 | |
1733 | node = hctx->numa_node; | |
1734 | if (node == NUMA_NO_NODE) | |
1735 | node = hctx->numa_node = set->numa_node; | |
1736 | ||
1737 | INIT_DELAYED_WORK(&hctx->run_work, blk_mq_run_work_fn); | |
1738 | INIT_DELAYED_WORK(&hctx->delay_work, blk_mq_delay_work_fn); | |
1739 | spin_lock_init(&hctx->lock); | |
1740 | INIT_LIST_HEAD(&hctx->dispatch); | |
1741 | hctx->queue = q; | |
1742 | hctx->queue_num = hctx_idx; | |
2404e607 | 1743 | hctx->flags = set->flags & ~BLK_MQ_F_TAG_SHARED; |
08e98fc6 ML |
1744 | |
1745 | blk_mq_init_cpu_notifier(&hctx->cpu_notifier, | |
1746 | blk_mq_hctx_notify, hctx); | |
1747 | blk_mq_register_cpu_notifier(&hctx->cpu_notifier); | |
1748 | ||
1749 | hctx->tags = set->tags[hctx_idx]; | |
320ae51f JA |
1750 | |
1751 | /* | |
08e98fc6 ML |
1752 | * Allocate space for all possible cpus to avoid allocation at |
1753 | * runtime | |
320ae51f | 1754 | */ |
08e98fc6 ML |
1755 | hctx->ctxs = kmalloc_node(nr_cpu_ids * sizeof(void *), |
1756 | GFP_KERNEL, node); | |
1757 | if (!hctx->ctxs) | |
1758 | goto unregister_cpu_notifier; | |
320ae51f | 1759 | |
08e98fc6 ML |
1760 | if (blk_mq_alloc_bitmap(&hctx->ctx_map, node)) |
1761 | goto free_ctxs; | |
320ae51f | 1762 | |
08e98fc6 | 1763 | hctx->nr_ctx = 0; |
320ae51f | 1764 | |
08e98fc6 ML |
1765 | if (set->ops->init_hctx && |
1766 | set->ops->init_hctx(hctx, set->driver_data, hctx_idx)) | |
1767 | goto free_bitmap; | |
320ae51f | 1768 | |
f70ced09 ML |
1769 | hctx->fq = blk_alloc_flush_queue(q, hctx->numa_node, set->cmd_size); |
1770 | if (!hctx->fq) | |
1771 | goto exit_hctx; | |
320ae51f | 1772 | |
f70ced09 ML |
1773 | if (set->ops->init_request && |
1774 | set->ops->init_request(set->driver_data, | |
1775 | hctx->fq->flush_rq, hctx_idx, | |
1776 | flush_start_tag + hctx_idx, node)) | |
1777 | goto free_fq; | |
320ae51f | 1778 | |
08e98fc6 | 1779 | return 0; |
320ae51f | 1780 | |
f70ced09 ML |
1781 | free_fq: |
1782 | kfree(hctx->fq); | |
1783 | exit_hctx: | |
1784 | if (set->ops->exit_hctx) | |
1785 | set->ops->exit_hctx(hctx, hctx_idx); | |
08e98fc6 ML |
1786 | free_bitmap: |
1787 | blk_mq_free_bitmap(&hctx->ctx_map); | |
1788 | free_ctxs: | |
1789 | kfree(hctx->ctxs); | |
1790 | unregister_cpu_notifier: | |
1791 | blk_mq_unregister_cpu_notifier(&hctx->cpu_notifier); | |
320ae51f | 1792 | |
08e98fc6 ML |
1793 | return -1; |
1794 | } | |
320ae51f | 1795 | |
320ae51f JA |
1796 | static void blk_mq_init_cpu_queues(struct request_queue *q, |
1797 | unsigned int nr_hw_queues) | |
1798 | { | |
1799 | unsigned int i; | |
1800 | ||
1801 | for_each_possible_cpu(i) { | |
1802 | struct blk_mq_ctx *__ctx = per_cpu_ptr(q->queue_ctx, i); | |
1803 | struct blk_mq_hw_ctx *hctx; | |
1804 | ||
1805 | memset(__ctx, 0, sizeof(*__ctx)); | |
1806 | __ctx->cpu = i; | |
1807 | spin_lock_init(&__ctx->lock); | |
1808 | INIT_LIST_HEAD(&__ctx->rq_list); | |
1809 | __ctx->queue = q; | |
1810 | ||
1811 | /* If the cpu isn't online, the cpu is mapped to first hctx */ | |
320ae51f JA |
1812 | if (!cpu_online(i)) |
1813 | continue; | |
1814 | ||
e4043dcf | 1815 | hctx = q->mq_ops->map_queue(q, i); |
e4043dcf | 1816 | |
320ae51f JA |
1817 | /* |
1818 | * Set local node, IFF we have more than one hw queue. If | |
1819 | * not, we remain on the home node of the device | |
1820 | */ | |
1821 | if (nr_hw_queues > 1 && hctx->numa_node == NUMA_NO_NODE) | |
bffed457 | 1822 | hctx->numa_node = local_memory_node(cpu_to_node(i)); |
320ae51f JA |
1823 | } |
1824 | } | |
1825 | ||
5778322e AM |
1826 | static void blk_mq_map_swqueue(struct request_queue *q, |
1827 | const struct cpumask *online_mask) | |
320ae51f JA |
1828 | { |
1829 | unsigned int i; | |
1830 | struct blk_mq_hw_ctx *hctx; | |
1831 | struct blk_mq_ctx *ctx; | |
2a34c087 | 1832 | struct blk_mq_tag_set *set = q->tag_set; |
320ae51f | 1833 | |
60de074b AM |
1834 | /* |
1835 | * Avoid others reading imcomplete hctx->cpumask through sysfs | |
1836 | */ | |
1837 | mutex_lock(&q->sysfs_lock); | |
1838 | ||
320ae51f | 1839 | queue_for_each_hw_ctx(q, hctx, i) { |
e4043dcf | 1840 | cpumask_clear(hctx->cpumask); |
320ae51f JA |
1841 | hctx->nr_ctx = 0; |
1842 | } | |
1843 | ||
1844 | /* | |
1845 | * Map software to hardware queues | |
1846 | */ | |
897bb0c7 | 1847 | for_each_possible_cpu(i) { |
320ae51f | 1848 | /* If the cpu isn't online, the cpu is mapped to first hctx */ |
5778322e | 1849 | if (!cpumask_test_cpu(i, online_mask)) |
e4043dcf JA |
1850 | continue; |
1851 | ||
897bb0c7 | 1852 | ctx = per_cpu_ptr(q->queue_ctx, i); |
320ae51f | 1853 | hctx = q->mq_ops->map_queue(q, i); |
868f2f0b | 1854 | |
e4043dcf | 1855 | cpumask_set_cpu(i, hctx->cpumask); |
320ae51f JA |
1856 | ctx->index_hw = hctx->nr_ctx; |
1857 | hctx->ctxs[hctx->nr_ctx++] = ctx; | |
1858 | } | |
506e931f | 1859 | |
60de074b AM |
1860 | mutex_unlock(&q->sysfs_lock); |
1861 | ||
506e931f | 1862 | queue_for_each_hw_ctx(q, hctx, i) { |
889fa31f CY |
1863 | struct blk_mq_ctxmap *map = &hctx->ctx_map; |
1864 | ||
484b4061 | 1865 | /* |
a68aafa5 JA |
1866 | * If no software queues are mapped to this hardware queue, |
1867 | * disable it and free the request entries. | |
484b4061 JA |
1868 | */ |
1869 | if (!hctx->nr_ctx) { | |
484b4061 JA |
1870 | if (set->tags[i]) { |
1871 | blk_mq_free_rq_map(set, set->tags[i], i); | |
1872 | set->tags[i] = NULL; | |
484b4061 | 1873 | } |
2a34c087 | 1874 | hctx->tags = NULL; |
484b4061 JA |
1875 | continue; |
1876 | } | |
1877 | ||
2a34c087 ML |
1878 | /* unmapped hw queue can be remapped after CPU topo changed */ |
1879 | if (!set->tags[i]) | |
1880 | set->tags[i] = blk_mq_init_rq_map(set, i); | |
1881 | hctx->tags = set->tags[i]; | |
1882 | WARN_ON(!hctx->tags); | |
1883 | ||
e0e827b9 | 1884 | cpumask_copy(hctx->tags->cpumask, hctx->cpumask); |
889fa31f CY |
1885 | /* |
1886 | * Set the map size to the number of mapped software queues. | |
1887 | * This is more accurate and more efficient than looping | |
1888 | * over all possibly mapped software queues. | |
1889 | */ | |
569fd0ce | 1890 | map->size = DIV_ROUND_UP(hctx->nr_ctx, map->bits_per_word); |
889fa31f | 1891 | |
484b4061 JA |
1892 | /* |
1893 | * Initialize batch roundrobin counts | |
1894 | */ | |
506e931f JA |
1895 | hctx->next_cpu = cpumask_first(hctx->cpumask); |
1896 | hctx->next_cpu_batch = BLK_MQ_CPU_WORK_BATCH; | |
1897 | } | |
320ae51f JA |
1898 | } |
1899 | ||
2404e607 | 1900 | static void queue_set_hctx_shared(struct request_queue *q, bool shared) |
0d2602ca JA |
1901 | { |
1902 | struct blk_mq_hw_ctx *hctx; | |
0d2602ca JA |
1903 | int i; |
1904 | ||
2404e607 JM |
1905 | queue_for_each_hw_ctx(q, hctx, i) { |
1906 | if (shared) | |
1907 | hctx->flags |= BLK_MQ_F_TAG_SHARED; | |
1908 | else | |
1909 | hctx->flags &= ~BLK_MQ_F_TAG_SHARED; | |
1910 | } | |
1911 | } | |
1912 | ||
1913 | static void blk_mq_update_tag_set_depth(struct blk_mq_tag_set *set, bool shared) | |
1914 | { | |
1915 | struct request_queue *q; | |
0d2602ca JA |
1916 | |
1917 | list_for_each_entry(q, &set->tag_list, tag_set_list) { | |
1918 | blk_mq_freeze_queue(q); | |
2404e607 | 1919 | queue_set_hctx_shared(q, shared); |
0d2602ca JA |
1920 | blk_mq_unfreeze_queue(q); |
1921 | } | |
1922 | } | |
1923 | ||
1924 | static void blk_mq_del_queue_tag_set(struct request_queue *q) | |
1925 | { | |
1926 | struct blk_mq_tag_set *set = q->tag_set; | |
1927 | ||
0d2602ca JA |
1928 | mutex_lock(&set->tag_list_lock); |
1929 | list_del_init(&q->tag_set_list); | |
2404e607 JM |
1930 | if (list_is_singular(&set->tag_list)) { |
1931 | /* just transitioned to unshared */ | |
1932 | set->flags &= ~BLK_MQ_F_TAG_SHARED; | |
1933 | /* update existing queue */ | |
1934 | blk_mq_update_tag_set_depth(set, false); | |
1935 | } | |
0d2602ca | 1936 | mutex_unlock(&set->tag_list_lock); |
0d2602ca JA |
1937 | } |
1938 | ||
1939 | static void blk_mq_add_queue_tag_set(struct blk_mq_tag_set *set, | |
1940 | struct request_queue *q) | |
1941 | { | |
1942 | q->tag_set = set; | |
1943 | ||
1944 | mutex_lock(&set->tag_list_lock); | |
2404e607 JM |
1945 | |
1946 | /* Check to see if we're transitioning to shared (from 1 to 2 queues). */ | |
1947 | if (!list_empty(&set->tag_list) && !(set->flags & BLK_MQ_F_TAG_SHARED)) { | |
1948 | set->flags |= BLK_MQ_F_TAG_SHARED; | |
1949 | /* update existing queue */ | |
1950 | blk_mq_update_tag_set_depth(set, true); | |
1951 | } | |
1952 | if (set->flags & BLK_MQ_F_TAG_SHARED) | |
1953 | queue_set_hctx_shared(q, true); | |
0d2602ca | 1954 | list_add_tail(&q->tag_set_list, &set->tag_list); |
2404e607 | 1955 | |
0d2602ca JA |
1956 | mutex_unlock(&set->tag_list_lock); |
1957 | } | |
1958 | ||
e09aae7e ML |
1959 | /* |
1960 | * It is the actual release handler for mq, but we do it from | |
1961 | * request queue's release handler for avoiding use-after-free | |
1962 | * and headache because q->mq_kobj shouldn't have been introduced, | |
1963 | * but we can't group ctx/kctx kobj without it. | |
1964 | */ | |
1965 | void blk_mq_release(struct request_queue *q) | |
1966 | { | |
1967 | struct blk_mq_hw_ctx *hctx; | |
1968 | unsigned int i; | |
1969 | ||
1970 | /* hctx kobj stays in hctx */ | |
c3b4afca ML |
1971 | queue_for_each_hw_ctx(q, hctx, i) { |
1972 | if (!hctx) | |
1973 | continue; | |
1974 | kfree(hctx->ctxs); | |
e09aae7e | 1975 | kfree(hctx); |
c3b4afca | 1976 | } |
e09aae7e | 1977 | |
a723bab3 AM |
1978 | kfree(q->mq_map); |
1979 | q->mq_map = NULL; | |
1980 | ||
e09aae7e ML |
1981 | kfree(q->queue_hw_ctx); |
1982 | ||
1983 | /* ctx kobj stays in queue_ctx */ | |
1984 | free_percpu(q->queue_ctx); | |
1985 | } | |
1986 | ||
24d2f903 | 1987 | struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *set) |
b62c21b7 MS |
1988 | { |
1989 | struct request_queue *uninit_q, *q; | |
1990 | ||
1991 | uninit_q = blk_alloc_queue_node(GFP_KERNEL, set->numa_node); | |
1992 | if (!uninit_q) | |
1993 | return ERR_PTR(-ENOMEM); | |
1994 | ||
1995 | q = blk_mq_init_allocated_queue(set, uninit_q); | |
1996 | if (IS_ERR(q)) | |
1997 | blk_cleanup_queue(uninit_q); | |
1998 | ||
1999 | return q; | |
2000 | } | |
2001 | EXPORT_SYMBOL(blk_mq_init_queue); | |
2002 | ||
868f2f0b KB |
2003 | static void blk_mq_realloc_hw_ctxs(struct blk_mq_tag_set *set, |
2004 | struct request_queue *q) | |
320ae51f | 2005 | { |
868f2f0b KB |
2006 | int i, j; |
2007 | struct blk_mq_hw_ctx **hctxs = q->queue_hw_ctx; | |
f14bbe77 | 2008 | |
868f2f0b | 2009 | blk_mq_sysfs_unregister(q); |
24d2f903 | 2010 | for (i = 0; i < set->nr_hw_queues; i++) { |
868f2f0b | 2011 | int node; |
f14bbe77 | 2012 | |
868f2f0b KB |
2013 | if (hctxs[i]) |
2014 | continue; | |
2015 | ||
2016 | node = blk_mq_hw_queue_to_node(q->mq_map, i); | |
cdef54dd CH |
2017 | hctxs[i] = kzalloc_node(sizeof(struct blk_mq_hw_ctx), |
2018 | GFP_KERNEL, node); | |
320ae51f | 2019 | if (!hctxs[i]) |
868f2f0b | 2020 | break; |
320ae51f | 2021 | |
a86073e4 | 2022 | if (!zalloc_cpumask_var_node(&hctxs[i]->cpumask, GFP_KERNEL, |
868f2f0b KB |
2023 | node)) { |
2024 | kfree(hctxs[i]); | |
2025 | hctxs[i] = NULL; | |
2026 | break; | |
2027 | } | |
e4043dcf | 2028 | |
0d2602ca | 2029 | atomic_set(&hctxs[i]->nr_active, 0); |
f14bbe77 | 2030 | hctxs[i]->numa_node = node; |
320ae51f | 2031 | hctxs[i]->queue_num = i; |
868f2f0b KB |
2032 | |
2033 | if (blk_mq_init_hctx(q, set, hctxs[i], i)) { | |
2034 | free_cpumask_var(hctxs[i]->cpumask); | |
2035 | kfree(hctxs[i]); | |
2036 | hctxs[i] = NULL; | |
2037 | break; | |
2038 | } | |
2039 | blk_mq_hctx_kobj_init(hctxs[i]); | |
320ae51f | 2040 | } |
868f2f0b KB |
2041 | for (j = i; j < q->nr_hw_queues; j++) { |
2042 | struct blk_mq_hw_ctx *hctx = hctxs[j]; | |
2043 | ||
2044 | if (hctx) { | |
2045 | if (hctx->tags) { | |
2046 | blk_mq_free_rq_map(set, hctx->tags, j); | |
2047 | set->tags[j] = NULL; | |
2048 | } | |
2049 | blk_mq_exit_hctx(q, set, hctx, j); | |
2050 | free_cpumask_var(hctx->cpumask); | |
2051 | kobject_put(&hctx->kobj); | |
2052 | kfree(hctx->ctxs); | |
2053 | kfree(hctx); | |
2054 | hctxs[j] = NULL; | |
2055 | ||
2056 | } | |
2057 | } | |
2058 | q->nr_hw_queues = i; | |
2059 | blk_mq_sysfs_register(q); | |
2060 | } | |
2061 | ||
2062 | struct request_queue *blk_mq_init_allocated_queue(struct blk_mq_tag_set *set, | |
2063 | struct request_queue *q) | |
2064 | { | |
66841672 ML |
2065 | /* mark the queue as mq asap */ |
2066 | q->mq_ops = set->ops; | |
2067 | ||
868f2f0b KB |
2068 | q->queue_ctx = alloc_percpu(struct blk_mq_ctx); |
2069 | if (!q->queue_ctx) | |
c7de5726 | 2070 | goto err_exit; |
868f2f0b KB |
2071 | |
2072 | q->queue_hw_ctx = kzalloc_node(nr_cpu_ids * sizeof(*(q->queue_hw_ctx)), | |
2073 | GFP_KERNEL, set->numa_node); | |
2074 | if (!q->queue_hw_ctx) | |
2075 | goto err_percpu; | |
2076 | ||
2077 | q->mq_map = blk_mq_make_queue_map(set); | |
2078 | if (!q->mq_map) | |
2079 | goto err_map; | |
2080 | ||
2081 | blk_mq_realloc_hw_ctxs(set, q); | |
2082 | if (!q->nr_hw_queues) | |
2083 | goto err_hctxs; | |
320ae51f | 2084 | |
287922eb | 2085 | INIT_WORK(&q->timeout_work, blk_mq_timeout_work); |
e56f698b | 2086 | blk_queue_rq_timeout(q, set->timeout ? set->timeout : 30 * HZ); |
320ae51f JA |
2087 | |
2088 | q->nr_queues = nr_cpu_ids; | |
320ae51f | 2089 | |
94eddfbe | 2090 | q->queue_flags |= QUEUE_FLAG_MQ_DEFAULT; |
320ae51f | 2091 | |
05f1dd53 JA |
2092 | if (!(set->flags & BLK_MQ_F_SG_MERGE)) |
2093 | q->queue_flags |= 1 << QUEUE_FLAG_NO_SG_MERGE; | |
2094 | ||
1be036e9 CH |
2095 | q->sg_reserved_size = INT_MAX; |
2096 | ||
6fca6a61 CH |
2097 | INIT_WORK(&q->requeue_work, blk_mq_requeue_work); |
2098 | INIT_LIST_HEAD(&q->requeue_list); | |
2099 | spin_lock_init(&q->requeue_lock); | |
2100 | ||
07068d5b JA |
2101 | if (q->nr_hw_queues > 1) |
2102 | blk_queue_make_request(q, blk_mq_make_request); | |
2103 | else | |
2104 | blk_queue_make_request(q, blk_sq_make_request); | |
2105 | ||
eba71768 JA |
2106 | /* |
2107 | * Do this after blk_queue_make_request() overrides it... | |
2108 | */ | |
2109 | q->nr_requests = set->queue_depth; | |
2110 | ||
24d2f903 CH |
2111 | if (set->ops->complete) |
2112 | blk_queue_softirq_done(q, set->ops->complete); | |
30a91cb4 | 2113 | |
24d2f903 | 2114 | blk_mq_init_cpu_queues(q, set->nr_hw_queues); |
320ae51f | 2115 | |
5778322e | 2116 | get_online_cpus(); |
320ae51f | 2117 | mutex_lock(&all_q_mutex); |
320ae51f | 2118 | |
4593fdbe | 2119 | list_add_tail(&q->all_q_node, &all_q_list); |
0d2602ca | 2120 | blk_mq_add_queue_tag_set(set, q); |
5778322e | 2121 | blk_mq_map_swqueue(q, cpu_online_mask); |
484b4061 | 2122 | |
4593fdbe | 2123 | mutex_unlock(&all_q_mutex); |
5778322e | 2124 | put_online_cpus(); |
4593fdbe | 2125 | |
320ae51f | 2126 | return q; |
18741986 | 2127 | |
320ae51f | 2128 | err_hctxs: |
868f2f0b | 2129 | kfree(q->mq_map); |
f14bbe77 | 2130 | err_map: |
868f2f0b | 2131 | kfree(q->queue_hw_ctx); |
320ae51f | 2132 | err_percpu: |
868f2f0b | 2133 | free_percpu(q->queue_ctx); |
c7de5726 ML |
2134 | err_exit: |
2135 | q->mq_ops = NULL; | |
320ae51f JA |
2136 | return ERR_PTR(-ENOMEM); |
2137 | } | |
b62c21b7 | 2138 | EXPORT_SYMBOL(blk_mq_init_allocated_queue); |
320ae51f JA |
2139 | |
2140 | void blk_mq_free_queue(struct request_queue *q) | |
2141 | { | |
624dbe47 | 2142 | struct blk_mq_tag_set *set = q->tag_set; |
320ae51f | 2143 | |
0e626368 AM |
2144 | mutex_lock(&all_q_mutex); |
2145 | list_del_init(&q->all_q_node); | |
2146 | mutex_unlock(&all_q_mutex); | |
2147 | ||
0d2602ca JA |
2148 | blk_mq_del_queue_tag_set(q); |
2149 | ||
624dbe47 ML |
2150 | blk_mq_exit_hw_queues(q, set, set->nr_hw_queues); |
2151 | blk_mq_free_hw_queues(q, set); | |
320ae51f | 2152 | } |
320ae51f JA |
2153 | |
2154 | /* Basically redo blk_mq_init_queue with queue frozen */ | |
5778322e AM |
2155 | static void blk_mq_queue_reinit(struct request_queue *q, |
2156 | const struct cpumask *online_mask) | |
320ae51f | 2157 | { |
4ecd4fef | 2158 | WARN_ON_ONCE(!atomic_read(&q->mq_freeze_depth)); |
320ae51f | 2159 | |
67aec14c JA |
2160 | blk_mq_sysfs_unregister(q); |
2161 | ||
5778322e | 2162 | blk_mq_update_queue_map(q->mq_map, q->nr_hw_queues, online_mask); |
320ae51f JA |
2163 | |
2164 | /* | |
2165 | * redo blk_mq_init_cpu_queues and blk_mq_init_hw_queues. FIXME: maybe | |
2166 | * we should change hctx numa_node according to new topology (this | |
2167 | * involves free and re-allocate memory, worthy doing?) | |
2168 | */ | |
2169 | ||
5778322e | 2170 | blk_mq_map_swqueue(q, online_mask); |
320ae51f | 2171 | |
67aec14c | 2172 | blk_mq_sysfs_register(q); |
320ae51f JA |
2173 | } |
2174 | ||
f618ef7c PG |
2175 | static int blk_mq_queue_reinit_notify(struct notifier_block *nb, |
2176 | unsigned long action, void *hcpu) | |
320ae51f JA |
2177 | { |
2178 | struct request_queue *q; | |
5778322e AM |
2179 | int cpu = (unsigned long)hcpu; |
2180 | /* | |
2181 | * New online cpumask which is going to be set in this hotplug event. | |
2182 | * Declare this cpumasks as global as cpu-hotplug operation is invoked | |
2183 | * one-by-one and dynamically allocating this could result in a failure. | |
2184 | */ | |
2185 | static struct cpumask online_new; | |
320ae51f JA |
2186 | |
2187 | /* | |
5778322e AM |
2188 | * Before hotadded cpu starts handling requests, new mappings must |
2189 | * be established. Otherwise, these requests in hw queue might | |
2190 | * never be dispatched. | |
2191 | * | |
2192 | * For example, there is a single hw queue (hctx) and two CPU queues | |
2193 | * (ctx0 for CPU0, and ctx1 for CPU1). | |
2194 | * | |
2195 | * Now CPU1 is just onlined and a request is inserted into | |
2196 | * ctx1->rq_list and set bit0 in pending bitmap as ctx1->index_hw is | |
2197 | * still zero. | |
2198 | * | |
2199 | * And then while running hw queue, flush_busy_ctxs() finds bit0 is | |
2200 | * set in pending bitmap and tries to retrieve requests in | |
2201 | * hctx->ctxs[0]->rq_list. But htx->ctxs[0] is a pointer to ctx0, | |
2202 | * so the request in ctx1->rq_list is ignored. | |
320ae51f | 2203 | */ |
5778322e AM |
2204 | switch (action & ~CPU_TASKS_FROZEN) { |
2205 | case CPU_DEAD: | |
2206 | case CPU_UP_CANCELED: | |
2207 | cpumask_copy(&online_new, cpu_online_mask); | |
2208 | break; | |
2209 | case CPU_UP_PREPARE: | |
2210 | cpumask_copy(&online_new, cpu_online_mask); | |
2211 | cpumask_set_cpu(cpu, &online_new); | |
2212 | break; | |
2213 | default: | |
320ae51f | 2214 | return NOTIFY_OK; |
5778322e | 2215 | } |
320ae51f JA |
2216 | |
2217 | mutex_lock(&all_q_mutex); | |
f3af020b TH |
2218 | |
2219 | /* | |
2220 | * We need to freeze and reinit all existing queues. Freezing | |
2221 | * involves synchronous wait for an RCU grace period and doing it | |
2222 | * one by one may take a long time. Start freezing all queues in | |
2223 | * one swoop and then wait for the completions so that freezing can | |
2224 | * take place in parallel. | |
2225 | */ | |
2226 | list_for_each_entry(q, &all_q_list, all_q_node) | |
2227 | blk_mq_freeze_queue_start(q); | |
f054b56c | 2228 | list_for_each_entry(q, &all_q_list, all_q_node) { |
f3af020b TH |
2229 | blk_mq_freeze_queue_wait(q); |
2230 | ||
f054b56c ML |
2231 | /* |
2232 | * timeout handler can't touch hw queue during the | |
2233 | * reinitialization | |
2234 | */ | |
2235 | del_timer_sync(&q->timeout); | |
2236 | } | |
2237 | ||
320ae51f | 2238 | list_for_each_entry(q, &all_q_list, all_q_node) |
5778322e | 2239 | blk_mq_queue_reinit(q, &online_new); |
f3af020b TH |
2240 | |
2241 | list_for_each_entry(q, &all_q_list, all_q_node) | |
2242 | blk_mq_unfreeze_queue(q); | |
2243 | ||
320ae51f JA |
2244 | mutex_unlock(&all_q_mutex); |
2245 | return NOTIFY_OK; | |
2246 | } | |
2247 | ||
a5164405 JA |
2248 | static int __blk_mq_alloc_rq_maps(struct blk_mq_tag_set *set) |
2249 | { | |
2250 | int i; | |
2251 | ||
2252 | for (i = 0; i < set->nr_hw_queues; i++) { | |
2253 | set->tags[i] = blk_mq_init_rq_map(set, i); | |
2254 | if (!set->tags[i]) | |
2255 | goto out_unwind; | |
2256 | } | |
2257 | ||
2258 | return 0; | |
2259 | ||
2260 | out_unwind: | |
2261 | while (--i >= 0) | |
2262 | blk_mq_free_rq_map(set, set->tags[i], i); | |
2263 | ||
a5164405 JA |
2264 | return -ENOMEM; |
2265 | } | |
2266 | ||
2267 | /* | |
2268 | * Allocate the request maps associated with this tag_set. Note that this | |
2269 | * may reduce the depth asked for, if memory is tight. set->queue_depth | |
2270 | * will be updated to reflect the allocated depth. | |
2271 | */ | |
2272 | static int blk_mq_alloc_rq_maps(struct blk_mq_tag_set *set) | |
2273 | { | |
2274 | unsigned int depth; | |
2275 | int err; | |
2276 | ||
2277 | depth = set->queue_depth; | |
2278 | do { | |
2279 | err = __blk_mq_alloc_rq_maps(set); | |
2280 | if (!err) | |
2281 | break; | |
2282 | ||
2283 | set->queue_depth >>= 1; | |
2284 | if (set->queue_depth < set->reserved_tags + BLK_MQ_TAG_MIN) { | |
2285 | err = -ENOMEM; | |
2286 | break; | |
2287 | } | |
2288 | } while (set->queue_depth); | |
2289 | ||
2290 | if (!set->queue_depth || err) { | |
2291 | pr_err("blk-mq: failed to allocate request map\n"); | |
2292 | return -ENOMEM; | |
2293 | } | |
2294 | ||
2295 | if (depth != set->queue_depth) | |
2296 | pr_info("blk-mq: reduced tag depth (%u -> %u)\n", | |
2297 | depth, set->queue_depth); | |
2298 | ||
2299 | return 0; | |
2300 | } | |
2301 | ||
f26cdc85 KB |
2302 | struct cpumask *blk_mq_tags_cpumask(struct blk_mq_tags *tags) |
2303 | { | |
2304 | return tags->cpumask; | |
2305 | } | |
2306 | EXPORT_SYMBOL_GPL(blk_mq_tags_cpumask); | |
2307 | ||
a4391c64 JA |
2308 | /* |
2309 | * Alloc a tag set to be associated with one or more request queues. | |
2310 | * May fail with EINVAL for various error conditions. May adjust the | |
2311 | * requested depth down, if if it too large. In that case, the set | |
2312 | * value will be stored in set->queue_depth. | |
2313 | */ | |
24d2f903 CH |
2314 | int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set) |
2315 | { | |
205fb5f5 BVA |
2316 | BUILD_BUG_ON(BLK_MQ_MAX_DEPTH > 1 << BLK_MQ_UNIQUE_TAG_BITS); |
2317 | ||
24d2f903 CH |
2318 | if (!set->nr_hw_queues) |
2319 | return -EINVAL; | |
a4391c64 | 2320 | if (!set->queue_depth) |
24d2f903 CH |
2321 | return -EINVAL; |
2322 | if (set->queue_depth < set->reserved_tags + BLK_MQ_TAG_MIN) | |
2323 | return -EINVAL; | |
2324 | ||
f9018ac9 | 2325 | if (!set->ops->queue_rq || !set->ops->map_queue) |
24d2f903 CH |
2326 | return -EINVAL; |
2327 | ||
a4391c64 JA |
2328 | if (set->queue_depth > BLK_MQ_MAX_DEPTH) { |
2329 | pr_info("blk-mq: reduced tag depth to %u\n", | |
2330 | BLK_MQ_MAX_DEPTH); | |
2331 | set->queue_depth = BLK_MQ_MAX_DEPTH; | |
2332 | } | |
24d2f903 | 2333 | |
6637fadf SL |
2334 | /* |
2335 | * If a crashdump is active, then we are potentially in a very | |
2336 | * memory constrained environment. Limit us to 1 queue and | |
2337 | * 64 tags to prevent using too much memory. | |
2338 | */ | |
2339 | if (is_kdump_kernel()) { | |
2340 | set->nr_hw_queues = 1; | |
2341 | set->queue_depth = min(64U, set->queue_depth); | |
2342 | } | |
868f2f0b KB |
2343 | /* |
2344 | * There is no use for more h/w queues than cpus. | |
2345 | */ | |
2346 | if (set->nr_hw_queues > nr_cpu_ids) | |
2347 | set->nr_hw_queues = nr_cpu_ids; | |
6637fadf | 2348 | |
868f2f0b | 2349 | set->tags = kzalloc_node(nr_cpu_ids * sizeof(struct blk_mq_tags *), |
24d2f903 CH |
2350 | GFP_KERNEL, set->numa_node); |
2351 | if (!set->tags) | |
a5164405 | 2352 | return -ENOMEM; |
24d2f903 | 2353 | |
a5164405 JA |
2354 | if (blk_mq_alloc_rq_maps(set)) |
2355 | goto enomem; | |
24d2f903 | 2356 | |
0d2602ca JA |
2357 | mutex_init(&set->tag_list_lock); |
2358 | INIT_LIST_HEAD(&set->tag_list); | |
2359 | ||
24d2f903 | 2360 | return 0; |
a5164405 | 2361 | enomem: |
5676e7b6 RE |
2362 | kfree(set->tags); |
2363 | set->tags = NULL; | |
24d2f903 CH |
2364 | return -ENOMEM; |
2365 | } | |
2366 | EXPORT_SYMBOL(blk_mq_alloc_tag_set); | |
2367 | ||
2368 | void blk_mq_free_tag_set(struct blk_mq_tag_set *set) | |
2369 | { | |
2370 | int i; | |
2371 | ||
868f2f0b | 2372 | for (i = 0; i < nr_cpu_ids; i++) { |
f42d79ab | 2373 | if (set->tags[i]) |
484b4061 JA |
2374 | blk_mq_free_rq_map(set, set->tags[i], i); |
2375 | } | |
2376 | ||
981bd189 | 2377 | kfree(set->tags); |
5676e7b6 | 2378 | set->tags = NULL; |
24d2f903 CH |
2379 | } |
2380 | EXPORT_SYMBOL(blk_mq_free_tag_set); | |
2381 | ||
e3a2b3f9 JA |
2382 | int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr) |
2383 | { | |
2384 | struct blk_mq_tag_set *set = q->tag_set; | |
2385 | struct blk_mq_hw_ctx *hctx; | |
2386 | int i, ret; | |
2387 | ||
2388 | if (!set || nr > set->queue_depth) | |
2389 | return -EINVAL; | |
2390 | ||
2391 | ret = 0; | |
2392 | queue_for_each_hw_ctx(q, hctx, i) { | |
e9137d4b KB |
2393 | if (!hctx->tags) |
2394 | continue; | |
e3a2b3f9 JA |
2395 | ret = blk_mq_tag_update_depth(hctx->tags, nr); |
2396 | if (ret) | |
2397 | break; | |
2398 | } | |
2399 | ||
2400 | if (!ret) | |
2401 | q->nr_requests = nr; | |
2402 | ||
2403 | return ret; | |
2404 | } | |
2405 | ||
868f2f0b KB |
2406 | void blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set, int nr_hw_queues) |
2407 | { | |
2408 | struct request_queue *q; | |
2409 | ||
2410 | if (nr_hw_queues > nr_cpu_ids) | |
2411 | nr_hw_queues = nr_cpu_ids; | |
2412 | if (nr_hw_queues < 1 || nr_hw_queues == set->nr_hw_queues) | |
2413 | return; | |
2414 | ||
2415 | list_for_each_entry(q, &set->tag_list, tag_set_list) | |
2416 | blk_mq_freeze_queue(q); | |
2417 | ||
2418 | set->nr_hw_queues = nr_hw_queues; | |
2419 | list_for_each_entry(q, &set->tag_list, tag_set_list) { | |
2420 | blk_mq_realloc_hw_ctxs(set, q); | |
2421 | ||
2422 | if (q->nr_hw_queues > 1) | |
2423 | blk_queue_make_request(q, blk_mq_make_request); | |
2424 | else | |
2425 | blk_queue_make_request(q, blk_sq_make_request); | |
2426 | ||
2427 | blk_mq_queue_reinit(q, cpu_online_mask); | |
2428 | } | |
2429 | ||
2430 | list_for_each_entry(q, &set->tag_list, tag_set_list) | |
2431 | blk_mq_unfreeze_queue(q); | |
2432 | } | |
2433 | EXPORT_SYMBOL_GPL(blk_mq_update_nr_hw_queues); | |
2434 | ||
676141e4 JA |
2435 | void blk_mq_disable_hotplug(void) |
2436 | { | |
2437 | mutex_lock(&all_q_mutex); | |
2438 | } | |
2439 | ||
2440 | void blk_mq_enable_hotplug(void) | |
2441 | { | |
2442 | mutex_unlock(&all_q_mutex); | |
2443 | } | |
2444 | ||
320ae51f JA |
2445 | static int __init blk_mq_init(void) |
2446 | { | |
320ae51f JA |
2447 | blk_mq_cpu_init(); |
2448 | ||
add703fd | 2449 | hotcpu_notifier(blk_mq_queue_reinit_notify, 0); |
320ae51f JA |
2450 | |
2451 | return 0; | |
2452 | } | |
2453 | subsys_initcall(blk_mq_init); |