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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> | |
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> | |
aedcd72f | 23 | #include <linux/crash_dump.h> |
320ae51f JA |
24 | |
25 | #include <trace/events/block.h> | |
26 | ||
27 | #include <linux/blk-mq.h> | |
28 | #include "blk.h" | |
29 | #include "blk-mq.h" | |
30 | #include "blk-mq-tag.h" | |
31 | ||
32 | static DEFINE_MUTEX(all_q_mutex); | |
33 | static LIST_HEAD(all_q_list); | |
34 | ||
35 | static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx); | |
36 | ||
320ae51f JA |
37 | /* |
38 | * Check if any of the ctx's have pending work in this hardware queue | |
39 | */ | |
40 | static bool blk_mq_hctx_has_pending(struct blk_mq_hw_ctx *hctx) | |
41 | { | |
42 | unsigned int i; | |
43 | ||
1429d7c9 JA |
44 | for (i = 0; i < hctx->ctx_map.map_size; i++) |
45 | if (hctx->ctx_map.map[i].word) | |
320ae51f JA |
46 | return true; |
47 | ||
48 | return false; | |
49 | } | |
50 | ||
1429d7c9 JA |
51 | static inline struct blk_align_bitmap *get_bm(struct blk_mq_hw_ctx *hctx, |
52 | struct blk_mq_ctx *ctx) | |
53 | { | |
54 | return &hctx->ctx_map.map[ctx->index_hw / hctx->ctx_map.bits_per_word]; | |
55 | } | |
56 | ||
57 | #define CTX_TO_BIT(hctx, ctx) \ | |
58 | ((ctx)->index_hw & ((hctx)->ctx_map.bits_per_word - 1)) | |
59 | ||
320ae51f JA |
60 | /* |
61 | * Mark this ctx as having pending work in this hardware queue | |
62 | */ | |
63 | static void blk_mq_hctx_mark_pending(struct blk_mq_hw_ctx *hctx, | |
64 | struct blk_mq_ctx *ctx) | |
65 | { | |
1429d7c9 JA |
66 | struct blk_align_bitmap *bm = get_bm(hctx, ctx); |
67 | ||
68 | if (!test_bit(CTX_TO_BIT(hctx, ctx), &bm->word)) | |
69 | set_bit(CTX_TO_BIT(hctx, ctx), &bm->word); | |
70 | } | |
71 | ||
72 | static void blk_mq_hctx_clear_pending(struct blk_mq_hw_ctx *hctx, | |
73 | struct blk_mq_ctx *ctx) | |
74 | { | |
75 | struct blk_align_bitmap *bm = get_bm(hctx, ctx); | |
76 | ||
77 | clear_bit(CTX_TO_BIT(hctx, ctx), &bm->word); | |
320ae51f JA |
78 | } |
79 | ||
320ae51f JA |
80 | static int blk_mq_queue_enter(struct request_queue *q) |
81 | { | |
add703fd TH |
82 | while (true) { |
83 | int ret; | |
320ae51f | 84 | |
add703fd TH |
85 | if (percpu_ref_tryget_live(&q->mq_usage_counter)) |
86 | return 0; | |
320ae51f | 87 | |
add703fd TH |
88 | ret = wait_event_interruptible(q->mq_freeze_wq, |
89 | !q->mq_freeze_depth || blk_queue_dying(q)); | |
90 | if (blk_queue_dying(q)) | |
91 | return -ENODEV; | |
92 | if (ret) | |
93 | return ret; | |
94 | } | |
320ae51f JA |
95 | } |
96 | ||
97 | static void blk_mq_queue_exit(struct request_queue *q) | |
98 | { | |
add703fd TH |
99 | percpu_ref_put(&q->mq_usage_counter); |
100 | } | |
101 | ||
102 | static void blk_mq_usage_counter_release(struct percpu_ref *ref) | |
103 | { | |
104 | struct request_queue *q = | |
105 | container_of(ref, struct request_queue, mq_usage_counter); | |
106 | ||
107 | wake_up_all(&q->mq_freeze_wq); | |
320ae51f JA |
108 | } |
109 | ||
72d6f02a TH |
110 | /* |
111 | * Guarantee no request is in use, so we can change any data structure of | |
112 | * the queue afterward. | |
113 | */ | |
114 | void blk_mq_freeze_queue(struct request_queue *q) | |
43a5e4e2 | 115 | { |
cddd5d17 TH |
116 | bool freeze; |
117 | ||
72d6f02a | 118 | spin_lock_irq(q->queue_lock); |
cddd5d17 | 119 | freeze = !q->mq_freeze_depth++; |
72d6f02a TH |
120 | spin_unlock_irq(q->queue_lock); |
121 | ||
cddd5d17 TH |
122 | if (freeze) { |
123 | percpu_ref_kill(&q->mq_usage_counter); | |
124 | blk_mq_run_queues(q, false); | |
125 | } | |
add703fd | 126 | wait_event(q->mq_freeze_wq, percpu_ref_is_zero(&q->mq_usage_counter)); |
43a5e4e2 ML |
127 | } |
128 | ||
320ae51f JA |
129 | static void blk_mq_unfreeze_queue(struct request_queue *q) |
130 | { | |
cddd5d17 | 131 | bool wake; |
320ae51f JA |
132 | |
133 | spin_lock_irq(q->queue_lock); | |
780db207 TH |
134 | wake = !--q->mq_freeze_depth; |
135 | WARN_ON_ONCE(q->mq_freeze_depth < 0); | |
320ae51f | 136 | spin_unlock_irq(q->queue_lock); |
add703fd TH |
137 | if (wake) { |
138 | percpu_ref_reinit(&q->mq_usage_counter); | |
320ae51f | 139 | wake_up_all(&q->mq_freeze_wq); |
add703fd | 140 | } |
320ae51f JA |
141 | } |
142 | ||
143 | bool blk_mq_can_queue(struct blk_mq_hw_ctx *hctx) | |
144 | { | |
145 | return blk_mq_has_free_tags(hctx->tags); | |
146 | } | |
147 | EXPORT_SYMBOL(blk_mq_can_queue); | |
148 | ||
94eddfbe JA |
149 | static void blk_mq_rq_ctx_init(struct request_queue *q, struct blk_mq_ctx *ctx, |
150 | struct request *rq, unsigned int rw_flags) | |
320ae51f | 151 | { |
94eddfbe JA |
152 | if (blk_queue_io_stat(q)) |
153 | rw_flags |= REQ_IO_STAT; | |
154 | ||
af76e555 CH |
155 | INIT_LIST_HEAD(&rq->queuelist); |
156 | /* csd/requeue_work/fifo_time is initialized before use */ | |
157 | rq->q = q; | |
320ae51f | 158 | rq->mq_ctx = ctx; |
0d2602ca | 159 | rq->cmd_flags |= rw_flags; |
af76e555 CH |
160 | /* do not touch atomic flags, it needs atomic ops against the timer */ |
161 | rq->cpu = -1; | |
af76e555 CH |
162 | INIT_HLIST_NODE(&rq->hash); |
163 | RB_CLEAR_NODE(&rq->rb_node); | |
af76e555 CH |
164 | rq->rq_disk = NULL; |
165 | rq->part = NULL; | |
3ee32372 | 166 | rq->start_time = jiffies; |
af76e555 CH |
167 | #ifdef CONFIG_BLK_CGROUP |
168 | rq->rl = NULL; | |
0fec08b4 | 169 | set_start_time_ns(rq); |
af76e555 CH |
170 | rq->io_start_time_ns = 0; |
171 | #endif | |
172 | rq->nr_phys_segments = 0; | |
173 | #if defined(CONFIG_BLK_DEV_INTEGRITY) | |
174 | rq->nr_integrity_segments = 0; | |
175 | #endif | |
af76e555 CH |
176 | rq->special = NULL; |
177 | /* tag was already set */ | |
178 | rq->errors = 0; | |
af76e555 | 179 | |
6f4a1626 TB |
180 | rq->cmd = rq->__cmd; |
181 | ||
af76e555 CH |
182 | rq->extra_len = 0; |
183 | rq->sense_len = 0; | |
184 | rq->resid_len = 0; | |
185 | rq->sense = NULL; | |
186 | ||
af76e555 | 187 | INIT_LIST_HEAD(&rq->timeout_list); |
f6be4fb4 JA |
188 | rq->timeout = 0; |
189 | ||
af76e555 CH |
190 | rq->end_io = NULL; |
191 | rq->end_io_data = NULL; | |
192 | rq->next_rq = NULL; | |
193 | ||
320ae51f JA |
194 | ctx->rq_dispatched[rw_is_sync(rw_flags)]++; |
195 | } | |
196 | ||
5dee8577 | 197 | static struct request * |
cb96a42c | 198 | __blk_mq_alloc_request(struct blk_mq_alloc_data *data, int rw) |
5dee8577 CH |
199 | { |
200 | struct request *rq; | |
201 | unsigned int tag; | |
202 | ||
cb96a42c | 203 | tag = blk_mq_get_tag(data); |
5dee8577 | 204 | if (tag != BLK_MQ_TAG_FAIL) { |
cb96a42c | 205 | rq = data->hctx->tags->rqs[tag]; |
5dee8577 | 206 | |
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; |
a492f075 | 227 | int ret; |
320ae51f | 228 | |
a492f075 JL |
229 | ret = blk_mq_queue_enter(q); |
230 | if (ret) | |
231 | return ERR_PTR(ret); | |
320ae51f | 232 | |
d852564f CH |
233 | ctx = blk_mq_get_ctx(q); |
234 | hctx = q->mq_ops->map_queue(q, ctx->cpu); | |
cb96a42c ML |
235 | blk_mq_set_alloc_data(&alloc_data, q, gfp & ~__GFP_WAIT, |
236 | reserved, ctx, hctx); | |
d852564f | 237 | |
cb96a42c | 238 | rq = __blk_mq_alloc_request(&alloc_data, rw); |
d852564f CH |
239 | if (!rq && (gfp & __GFP_WAIT)) { |
240 | __blk_mq_run_hw_queue(hctx); | |
241 | blk_mq_put_ctx(ctx); | |
242 | ||
243 | ctx = blk_mq_get_ctx(q); | |
244 | hctx = q->mq_ops->map_queue(q, ctx->cpu); | |
cb96a42c ML |
245 | blk_mq_set_alloc_data(&alloc_data, q, gfp, reserved, ctx, |
246 | hctx); | |
247 | rq = __blk_mq_alloc_request(&alloc_data, rw); | |
248 | ctx = alloc_data.ctx; | |
d852564f CH |
249 | } |
250 | blk_mq_put_ctx(ctx); | |
a492f075 JL |
251 | if (!rq) |
252 | return ERR_PTR(-EWOULDBLOCK); | |
320ae51f JA |
253 | return rq; |
254 | } | |
4bb659b1 | 255 | EXPORT_SYMBOL(blk_mq_alloc_request); |
320ae51f | 256 | |
320ae51f JA |
257 | static void __blk_mq_free_request(struct blk_mq_hw_ctx *hctx, |
258 | struct blk_mq_ctx *ctx, struct request *rq) | |
259 | { | |
260 | const int tag = rq->tag; | |
261 | struct request_queue *q = rq->q; | |
262 | ||
0d2602ca JA |
263 | if (rq->cmd_flags & REQ_MQ_INFLIGHT) |
264 | atomic_dec(&hctx->nr_active); | |
683d0e12 | 265 | rq->cmd_flags = 0; |
0d2602ca | 266 | |
af76e555 | 267 | clear_bit(REQ_ATOM_STARTED, &rq->atomic_flags); |
0d2602ca | 268 | blk_mq_put_tag(hctx, tag, &ctx->last_tag); |
320ae51f JA |
269 | blk_mq_queue_exit(q); |
270 | } | |
271 | ||
272 | void blk_mq_free_request(struct request *rq) | |
273 | { | |
274 | struct blk_mq_ctx *ctx = rq->mq_ctx; | |
275 | struct blk_mq_hw_ctx *hctx; | |
276 | struct request_queue *q = rq->q; | |
277 | ||
278 | ctx->rq_completed[rq_is_sync(rq)]++; | |
279 | ||
280 | hctx = q->mq_ops->map_queue(q, ctx->cpu); | |
281 | __blk_mq_free_request(hctx, ctx, rq); | |
282 | } | |
283 | ||
8727af4b CH |
284 | /* |
285 | * Clone all relevant state from a request that has been put on hold in | |
286 | * the flush state machine into the preallocated flush request that hangs | |
287 | * off the request queue. | |
288 | * | |
289 | * For a driver the flush request should be invisible, that's why we are | |
290 | * impersonating the original request here. | |
291 | */ | |
292 | void blk_mq_clone_flush_request(struct request *flush_rq, | |
293 | struct request *orig_rq) | |
294 | { | |
295 | struct blk_mq_hw_ctx *hctx = | |
296 | orig_rq->q->mq_ops->map_queue(orig_rq->q, orig_rq->mq_ctx->cpu); | |
297 | ||
298 | flush_rq->mq_ctx = orig_rq->mq_ctx; | |
299 | flush_rq->tag = orig_rq->tag; | |
300 | memcpy(blk_mq_rq_to_pdu(flush_rq), blk_mq_rq_to_pdu(orig_rq), | |
301 | hctx->cmd_size); | |
302 | } | |
303 | ||
c8a446ad | 304 | inline void __blk_mq_end_request(struct request *rq, int error) |
320ae51f | 305 | { |
0d11e6ac ML |
306 | blk_account_io_done(rq); |
307 | ||
91b63639 | 308 | if (rq->end_io) { |
320ae51f | 309 | rq->end_io(rq, error); |
91b63639 CH |
310 | } else { |
311 | if (unlikely(blk_bidi_rq(rq))) | |
312 | blk_mq_free_request(rq->next_rq); | |
320ae51f | 313 | blk_mq_free_request(rq); |
91b63639 | 314 | } |
320ae51f | 315 | } |
c8a446ad | 316 | EXPORT_SYMBOL(__blk_mq_end_request); |
63151a44 | 317 | |
c8a446ad | 318 | void blk_mq_end_request(struct request *rq, int error) |
63151a44 CH |
319 | { |
320 | if (blk_update_request(rq, error, blk_rq_bytes(rq))) | |
321 | BUG(); | |
c8a446ad | 322 | __blk_mq_end_request(rq, error); |
63151a44 | 323 | } |
c8a446ad | 324 | EXPORT_SYMBOL(blk_mq_end_request); |
320ae51f | 325 | |
30a91cb4 | 326 | static void __blk_mq_complete_request_remote(void *data) |
320ae51f | 327 | { |
3d6efbf6 | 328 | struct request *rq = data; |
320ae51f | 329 | |
30a91cb4 | 330 | rq->q->softirq_done_fn(rq); |
320ae51f | 331 | } |
320ae51f | 332 | |
ed851860 | 333 | static void blk_mq_ipi_complete_request(struct request *rq) |
320ae51f JA |
334 | { |
335 | struct blk_mq_ctx *ctx = rq->mq_ctx; | |
38535201 | 336 | bool shared = false; |
320ae51f JA |
337 | int cpu; |
338 | ||
38535201 | 339 | if (!test_bit(QUEUE_FLAG_SAME_COMP, &rq->q->queue_flags)) { |
30a91cb4 CH |
340 | rq->q->softirq_done_fn(rq); |
341 | return; | |
342 | } | |
320ae51f JA |
343 | |
344 | cpu = get_cpu(); | |
38535201 CH |
345 | if (!test_bit(QUEUE_FLAG_SAME_FORCE, &rq->q->queue_flags)) |
346 | shared = cpus_share_cache(cpu, ctx->cpu); | |
347 | ||
348 | if (cpu != ctx->cpu && !shared && cpu_online(ctx->cpu)) { | |
30a91cb4 | 349 | rq->csd.func = __blk_mq_complete_request_remote; |
3d6efbf6 CH |
350 | rq->csd.info = rq; |
351 | rq->csd.flags = 0; | |
c46fff2a | 352 | smp_call_function_single_async(ctx->cpu, &rq->csd); |
3d6efbf6 | 353 | } else { |
30a91cb4 | 354 | rq->q->softirq_done_fn(rq); |
3d6efbf6 | 355 | } |
320ae51f JA |
356 | put_cpu(); |
357 | } | |
30a91cb4 | 358 | |
ed851860 JA |
359 | void __blk_mq_complete_request(struct request *rq) |
360 | { | |
361 | struct request_queue *q = rq->q; | |
362 | ||
363 | if (!q->softirq_done_fn) | |
c8a446ad | 364 | blk_mq_end_request(rq, rq->errors); |
ed851860 JA |
365 | else |
366 | blk_mq_ipi_complete_request(rq); | |
367 | } | |
368 | ||
30a91cb4 CH |
369 | /** |
370 | * blk_mq_complete_request - end I/O on a request | |
371 | * @rq: the request being processed | |
372 | * | |
373 | * Description: | |
374 | * Ends all I/O on a request. It does not handle partial completions. | |
375 | * The actual completion happens out-of-order, through a IPI handler. | |
376 | **/ | |
377 | void blk_mq_complete_request(struct request *rq) | |
378 | { | |
95f09684 JA |
379 | struct request_queue *q = rq->q; |
380 | ||
381 | if (unlikely(blk_should_fake_timeout(q))) | |
30a91cb4 | 382 | return; |
ed851860 JA |
383 | if (!blk_mark_rq_complete(rq)) |
384 | __blk_mq_complete_request(rq); | |
30a91cb4 CH |
385 | } |
386 | EXPORT_SYMBOL(blk_mq_complete_request); | |
320ae51f | 387 | |
e2490073 | 388 | void blk_mq_start_request(struct request *rq) |
320ae51f JA |
389 | { |
390 | struct request_queue *q = rq->q; | |
391 | ||
392 | trace_block_rq_issue(q, rq); | |
393 | ||
742ee69b | 394 | rq->resid_len = blk_rq_bytes(rq); |
91b63639 CH |
395 | if (unlikely(blk_bidi_rq(rq))) |
396 | rq->next_rq->resid_len = blk_rq_bytes(rq->next_rq); | |
742ee69b | 397 | |
2b8393b4 | 398 | blk_add_timer(rq); |
87ee7b11 | 399 | |
538b7534 JA |
400 | /* |
401 | * Ensure that ->deadline is visible before set the started | |
402 | * flag and clear the completed flag. | |
403 | */ | |
404 | smp_mb__before_atomic(); | |
405 | ||
87ee7b11 JA |
406 | /* |
407 | * Mark us as started and clear complete. Complete might have been | |
408 | * set if requeue raced with timeout, which then marked it as | |
409 | * complete. So be sure to clear complete again when we start | |
410 | * the request, otherwise we'll ignore the completion event. | |
411 | */ | |
4b570521 JA |
412 | if (!test_bit(REQ_ATOM_STARTED, &rq->atomic_flags)) |
413 | set_bit(REQ_ATOM_STARTED, &rq->atomic_flags); | |
414 | if (test_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags)) | |
415 | clear_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags); | |
49f5baa5 CH |
416 | |
417 | if (q->dma_drain_size && blk_rq_bytes(rq)) { | |
418 | /* | |
419 | * Make sure space for the drain appears. We know we can do | |
420 | * this because max_hw_segments has been adjusted to be one | |
421 | * fewer than the device can handle. | |
422 | */ | |
423 | rq->nr_phys_segments++; | |
424 | } | |
320ae51f | 425 | } |
e2490073 | 426 | EXPORT_SYMBOL(blk_mq_start_request); |
320ae51f | 427 | |
ed0791b2 | 428 | static void __blk_mq_requeue_request(struct request *rq) |
320ae51f JA |
429 | { |
430 | struct request_queue *q = rq->q; | |
431 | ||
432 | trace_block_rq_requeue(q, rq); | |
49f5baa5 | 433 | |
e2490073 CH |
434 | if (test_and_clear_bit(REQ_ATOM_STARTED, &rq->atomic_flags)) { |
435 | if (q->dma_drain_size && blk_rq_bytes(rq)) | |
436 | rq->nr_phys_segments--; | |
437 | } | |
320ae51f JA |
438 | } |
439 | ||
ed0791b2 CH |
440 | void blk_mq_requeue_request(struct request *rq) |
441 | { | |
ed0791b2 | 442 | __blk_mq_requeue_request(rq); |
ed0791b2 | 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 | ||
8b957415 JA |
476 | /* |
477 | * Use the start variant of queue running here, so that running | |
478 | * the requeue work will kick stopped queues. | |
479 | */ | |
480 | blk_mq_start_hw_queues(q); | |
6fca6a61 CH |
481 | } |
482 | ||
483 | void blk_mq_add_to_requeue_list(struct request *rq, bool at_head) | |
484 | { | |
485 | struct request_queue *q = rq->q; | |
486 | unsigned long flags; | |
487 | ||
488 | /* | |
489 | * We abuse this flag that is otherwise used by the I/O scheduler to | |
490 | * request head insertation from the workqueue. | |
491 | */ | |
492 | BUG_ON(rq->cmd_flags & REQ_SOFTBARRIER); | |
493 | ||
494 | spin_lock_irqsave(&q->requeue_lock, flags); | |
495 | if (at_head) { | |
496 | rq->cmd_flags |= REQ_SOFTBARRIER; | |
497 | list_add(&rq->queuelist, &q->requeue_list); | |
498 | } else { | |
499 | list_add_tail(&rq->queuelist, &q->requeue_list); | |
500 | } | |
501 | spin_unlock_irqrestore(&q->requeue_lock, flags); | |
502 | } | |
503 | EXPORT_SYMBOL(blk_mq_add_to_requeue_list); | |
504 | ||
505 | void blk_mq_kick_requeue_list(struct request_queue *q) | |
506 | { | |
507 | kblockd_schedule_work(&q->requeue_work); | |
508 | } | |
509 | EXPORT_SYMBOL(blk_mq_kick_requeue_list); | |
510 | ||
0e62f51f | 511 | static inline bool is_flush_request(struct request *rq, unsigned int tag) |
24d2f903 | 512 | { |
0e62f51f JA |
513 | return ((rq->cmd_flags & REQ_FLUSH_SEQ) && |
514 | rq->q->flush_rq->tag == tag); | |
515 | } | |
516 | ||
517 | struct request *blk_mq_tag_to_rq(struct blk_mq_tags *tags, unsigned int tag) | |
518 | { | |
519 | struct request *rq = tags->rqs[tag]; | |
22302375 | 520 | |
0e62f51f JA |
521 | if (!is_flush_request(rq, tag)) |
522 | return rq; | |
22302375 | 523 | |
0e62f51f | 524 | return rq->q->flush_rq; |
24d2f903 CH |
525 | } |
526 | EXPORT_SYMBOL(blk_mq_tag_to_rq); | |
527 | ||
46f92d42 CH |
528 | struct blk_mq_timeout_data { |
529 | unsigned long next; | |
530 | unsigned int next_set; | |
531 | }; | |
532 | ||
90415837 | 533 | void blk_mq_rq_timed_out(struct request *req, bool reserved) |
87ee7b11 | 534 | { |
46f92d42 CH |
535 | struct blk_mq_ops *ops = req->q->mq_ops; |
536 | enum blk_eh_timer_return ret = BLK_EH_RESET_TIMER; | |
87ee7b11 JA |
537 | |
538 | /* | |
539 | * We know that complete is set at this point. If STARTED isn't set | |
540 | * anymore, then the request isn't active and the "timeout" should | |
541 | * just be ignored. This can happen due to the bitflag ordering. | |
542 | * Timeout first checks if STARTED is set, and if it is, assumes | |
543 | * the request is active. But if we race with completion, then | |
544 | * we both flags will get cleared. So check here again, and ignore | |
545 | * a timeout event with a request that isn't active. | |
546 | */ | |
46f92d42 CH |
547 | if (!test_bit(REQ_ATOM_STARTED, &req->atomic_flags)) |
548 | return; | |
87ee7b11 | 549 | |
46f92d42 | 550 | if (ops->timeout) |
0152fb6b | 551 | ret = ops->timeout(req, reserved); |
46f92d42 CH |
552 | |
553 | switch (ret) { | |
554 | case BLK_EH_HANDLED: | |
555 | __blk_mq_complete_request(req); | |
556 | break; | |
557 | case BLK_EH_RESET_TIMER: | |
558 | blk_add_timer(req); | |
559 | blk_clear_rq_complete(req); | |
560 | break; | |
561 | case BLK_EH_NOT_HANDLED: | |
562 | break; | |
563 | default: | |
564 | printk(KERN_ERR "block: bad eh return: %d\n", ret); | |
565 | break; | |
566 | } | |
87ee7b11 | 567 | } |
81481eb4 | 568 | |
81481eb4 CH |
569 | static void blk_mq_check_expired(struct blk_mq_hw_ctx *hctx, |
570 | struct request *rq, void *priv, bool reserved) | |
571 | { | |
572 | struct blk_mq_timeout_data *data = priv; | |
87ee7b11 | 573 | |
46f92d42 CH |
574 | if (!test_bit(REQ_ATOM_STARTED, &rq->atomic_flags)) |
575 | return; | |
576 | ||
577 | if (time_after_eq(jiffies, rq->deadline)) { | |
578 | if (!blk_mark_rq_complete(rq)) | |
0152fb6b | 579 | blk_mq_rq_timed_out(rq, reserved); |
46f92d42 CH |
580 | } else if (!data->next_set || time_after(data->next, rq->deadline)) { |
581 | data->next = rq->deadline; | |
582 | data->next_set = 1; | |
583 | } | |
81481eb4 CH |
584 | } |
585 | ||
586 | static void blk_mq_rq_timer(unsigned long priv) | |
320ae51f | 587 | { |
81481eb4 CH |
588 | struct request_queue *q = (struct request_queue *)priv; |
589 | struct blk_mq_timeout_data data = { | |
590 | .next = 0, | |
591 | .next_set = 0, | |
592 | }; | |
320ae51f | 593 | struct blk_mq_hw_ctx *hctx; |
81481eb4 | 594 | int i; |
320ae51f | 595 | |
484b4061 JA |
596 | queue_for_each_hw_ctx(q, hctx, i) { |
597 | /* | |
598 | * If not software queues are currently mapped to this | |
599 | * hardware queue, there's nothing to check | |
600 | */ | |
601 | if (!hctx->nr_ctx || !hctx->tags) | |
602 | continue; | |
603 | ||
81481eb4 | 604 | blk_mq_tag_busy_iter(hctx, blk_mq_check_expired, &data); |
484b4061 | 605 | } |
320ae51f | 606 | |
81481eb4 CH |
607 | if (data.next_set) { |
608 | data.next = blk_rq_timeout(round_jiffies_up(data.next)); | |
609 | mod_timer(&q->timeout, data.next); | |
0d2602ca JA |
610 | } else { |
611 | queue_for_each_hw_ctx(q, hctx, i) | |
612 | blk_mq_tag_idle(hctx); | |
613 | } | |
320ae51f JA |
614 | } |
615 | ||
616 | /* | |
617 | * Reverse check our software queue for entries that we could potentially | |
618 | * merge with. Currently includes a hand-wavy stop count of 8, to not spend | |
619 | * too much time checking for merges. | |
620 | */ | |
621 | static bool blk_mq_attempt_merge(struct request_queue *q, | |
622 | struct blk_mq_ctx *ctx, struct bio *bio) | |
623 | { | |
624 | struct request *rq; | |
625 | int checked = 8; | |
626 | ||
627 | list_for_each_entry_reverse(rq, &ctx->rq_list, queuelist) { | |
628 | int el_ret; | |
629 | ||
630 | if (!checked--) | |
631 | break; | |
632 | ||
633 | if (!blk_rq_merge_ok(rq, bio)) | |
634 | continue; | |
635 | ||
636 | el_ret = blk_try_merge(rq, bio); | |
637 | if (el_ret == ELEVATOR_BACK_MERGE) { | |
638 | if (bio_attempt_back_merge(q, rq, bio)) { | |
639 | ctx->rq_merged++; | |
640 | return true; | |
641 | } | |
642 | break; | |
643 | } else if (el_ret == ELEVATOR_FRONT_MERGE) { | |
644 | if (bio_attempt_front_merge(q, rq, bio)) { | |
645 | ctx->rq_merged++; | |
646 | return true; | |
647 | } | |
648 | break; | |
649 | } | |
650 | } | |
651 | ||
652 | return false; | |
653 | } | |
654 | ||
1429d7c9 JA |
655 | /* |
656 | * Process software queues that have been marked busy, splicing them | |
657 | * to the for-dispatch | |
658 | */ | |
659 | static void flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, struct list_head *list) | |
660 | { | |
661 | struct blk_mq_ctx *ctx; | |
662 | int i; | |
663 | ||
664 | for (i = 0; i < hctx->ctx_map.map_size; i++) { | |
665 | struct blk_align_bitmap *bm = &hctx->ctx_map.map[i]; | |
666 | unsigned int off, bit; | |
667 | ||
668 | if (!bm->word) | |
669 | continue; | |
670 | ||
671 | bit = 0; | |
672 | off = i * hctx->ctx_map.bits_per_word; | |
673 | do { | |
674 | bit = find_next_bit(&bm->word, bm->depth, bit); | |
675 | if (bit >= bm->depth) | |
676 | break; | |
677 | ||
678 | ctx = hctx->ctxs[bit + off]; | |
679 | clear_bit(bit, &bm->word); | |
680 | spin_lock(&ctx->lock); | |
681 | list_splice_tail_init(&ctx->rq_list, list); | |
682 | spin_unlock(&ctx->lock); | |
683 | ||
684 | bit++; | |
685 | } while (1); | |
686 | } | |
687 | } | |
688 | ||
320ae51f JA |
689 | /* |
690 | * Run this hardware queue, pulling any software queues mapped to it in. | |
691 | * Note that this function currently has various problems around ordering | |
692 | * of IO. In particular, we'd like FIFO behaviour on handling existing | |
693 | * items on the hctx->dispatch list. Ignore that for now. | |
694 | */ | |
695 | static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx) | |
696 | { | |
697 | struct request_queue *q = hctx->queue; | |
320ae51f JA |
698 | struct request *rq; |
699 | LIST_HEAD(rq_list); | |
1429d7c9 | 700 | int queued; |
320ae51f | 701 | |
fd1270d5 | 702 | WARN_ON(!cpumask_test_cpu(raw_smp_processor_id(), hctx->cpumask)); |
e4043dcf | 703 | |
5d12f905 | 704 | if (unlikely(test_bit(BLK_MQ_S_STOPPED, &hctx->state))) |
320ae51f JA |
705 | return; |
706 | ||
707 | hctx->run++; | |
708 | ||
709 | /* | |
710 | * Touch any software queue that has pending entries. | |
711 | */ | |
1429d7c9 | 712 | flush_busy_ctxs(hctx, &rq_list); |
320ae51f JA |
713 | |
714 | /* | |
715 | * If we have previous entries on our dispatch list, grab them | |
716 | * and stuff them at the front for more fair dispatch. | |
717 | */ | |
718 | if (!list_empty_careful(&hctx->dispatch)) { | |
719 | spin_lock(&hctx->lock); | |
720 | if (!list_empty(&hctx->dispatch)) | |
721 | list_splice_init(&hctx->dispatch, &rq_list); | |
722 | spin_unlock(&hctx->lock); | |
723 | } | |
724 | ||
320ae51f JA |
725 | /* |
726 | * Now process all the entries, sending them to the driver. | |
727 | */ | |
1429d7c9 | 728 | queued = 0; |
320ae51f JA |
729 | while (!list_empty(&rq_list)) { |
730 | int ret; | |
731 | ||
732 | rq = list_first_entry(&rq_list, struct request, queuelist); | |
733 | list_del_init(&rq->queuelist); | |
320ae51f | 734 | |
bf572297 | 735 | ret = q->mq_ops->queue_rq(hctx, rq, list_empty(&rq_list)); |
320ae51f JA |
736 | switch (ret) { |
737 | case BLK_MQ_RQ_QUEUE_OK: | |
738 | queued++; | |
739 | continue; | |
740 | case BLK_MQ_RQ_QUEUE_BUSY: | |
320ae51f | 741 | list_add(&rq->queuelist, &rq_list); |
ed0791b2 | 742 | __blk_mq_requeue_request(rq); |
320ae51f JA |
743 | break; |
744 | default: | |
745 | pr_err("blk-mq: bad return on queue: %d\n", ret); | |
320ae51f | 746 | case BLK_MQ_RQ_QUEUE_ERROR: |
1e93b8c2 | 747 | rq->errors = -EIO; |
c8a446ad | 748 | blk_mq_end_request(rq, rq->errors); |
320ae51f JA |
749 | break; |
750 | } | |
751 | ||
752 | if (ret == BLK_MQ_RQ_QUEUE_BUSY) | |
753 | break; | |
754 | } | |
755 | ||
756 | if (!queued) | |
757 | hctx->dispatched[0]++; | |
758 | else if (queued < (1 << (BLK_MQ_MAX_DISPATCH_ORDER - 1))) | |
759 | hctx->dispatched[ilog2(queued) + 1]++; | |
760 | ||
761 | /* | |
762 | * Any items that need requeuing? Stuff them into hctx->dispatch, | |
763 | * that is where we will continue on next queue run. | |
764 | */ | |
765 | if (!list_empty(&rq_list)) { | |
766 | spin_lock(&hctx->lock); | |
767 | list_splice(&rq_list, &hctx->dispatch); | |
768 | spin_unlock(&hctx->lock); | |
769 | } | |
770 | } | |
771 | ||
506e931f JA |
772 | /* |
773 | * It'd be great if the workqueue API had a way to pass | |
774 | * in a mask and had some smarts for more clever placement. | |
775 | * For now we just round-robin here, switching for every | |
776 | * BLK_MQ_CPU_WORK_BATCH queued items. | |
777 | */ | |
778 | static int blk_mq_hctx_next_cpu(struct blk_mq_hw_ctx *hctx) | |
779 | { | |
780 | int cpu = hctx->next_cpu; | |
781 | ||
782 | if (--hctx->next_cpu_batch <= 0) { | |
783 | int next_cpu; | |
784 | ||
785 | next_cpu = cpumask_next(hctx->next_cpu, hctx->cpumask); | |
786 | if (next_cpu >= nr_cpu_ids) | |
787 | next_cpu = cpumask_first(hctx->cpumask); | |
788 | ||
789 | hctx->next_cpu = next_cpu; | |
790 | hctx->next_cpu_batch = BLK_MQ_CPU_WORK_BATCH; | |
791 | } | |
792 | ||
793 | return cpu; | |
794 | } | |
795 | ||
320ae51f JA |
796 | void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async) |
797 | { | |
5d12f905 | 798 | if (unlikely(test_bit(BLK_MQ_S_STOPPED, &hctx->state))) |
320ae51f JA |
799 | return; |
800 | ||
e4043dcf | 801 | if (!async && cpumask_test_cpu(smp_processor_id(), hctx->cpumask)) |
320ae51f | 802 | __blk_mq_run_hw_queue(hctx); |
e4043dcf | 803 | else if (hctx->queue->nr_hw_queues == 1) |
70f4db63 | 804 | kblockd_schedule_delayed_work(&hctx->run_work, 0); |
e4043dcf JA |
805 | else { |
806 | unsigned int cpu; | |
807 | ||
506e931f | 808 | cpu = blk_mq_hctx_next_cpu(hctx); |
70f4db63 | 809 | kblockd_schedule_delayed_work_on(cpu, &hctx->run_work, 0); |
e4043dcf | 810 | } |
320ae51f JA |
811 | } |
812 | ||
813 | void blk_mq_run_queues(struct request_queue *q, bool async) | |
814 | { | |
815 | struct blk_mq_hw_ctx *hctx; | |
816 | int i; | |
817 | ||
818 | queue_for_each_hw_ctx(q, hctx, i) { | |
819 | if ((!blk_mq_hctx_has_pending(hctx) && | |
820 | list_empty_careful(&hctx->dispatch)) || | |
5d12f905 | 821 | test_bit(BLK_MQ_S_STOPPED, &hctx->state)) |
320ae51f JA |
822 | continue; |
823 | ||
e4043dcf | 824 | preempt_disable(); |
320ae51f | 825 | blk_mq_run_hw_queue(hctx, async); |
e4043dcf | 826 | preempt_enable(); |
320ae51f JA |
827 | } |
828 | } | |
829 | EXPORT_SYMBOL(blk_mq_run_queues); | |
830 | ||
831 | void blk_mq_stop_hw_queue(struct blk_mq_hw_ctx *hctx) | |
832 | { | |
70f4db63 CH |
833 | cancel_delayed_work(&hctx->run_work); |
834 | cancel_delayed_work(&hctx->delay_work); | |
320ae51f JA |
835 | set_bit(BLK_MQ_S_STOPPED, &hctx->state); |
836 | } | |
837 | EXPORT_SYMBOL(blk_mq_stop_hw_queue); | |
838 | ||
280d45f6 CH |
839 | void blk_mq_stop_hw_queues(struct request_queue *q) |
840 | { | |
841 | struct blk_mq_hw_ctx *hctx; | |
842 | int i; | |
843 | ||
844 | queue_for_each_hw_ctx(q, hctx, i) | |
845 | blk_mq_stop_hw_queue(hctx); | |
846 | } | |
847 | EXPORT_SYMBOL(blk_mq_stop_hw_queues); | |
848 | ||
320ae51f JA |
849 | void blk_mq_start_hw_queue(struct blk_mq_hw_ctx *hctx) |
850 | { | |
851 | clear_bit(BLK_MQ_S_STOPPED, &hctx->state); | |
e4043dcf JA |
852 | |
853 | preempt_disable(); | |
0ffbce80 | 854 | blk_mq_run_hw_queue(hctx, false); |
e4043dcf | 855 | preempt_enable(); |
320ae51f JA |
856 | } |
857 | EXPORT_SYMBOL(blk_mq_start_hw_queue); | |
858 | ||
2f268556 CH |
859 | void blk_mq_start_hw_queues(struct request_queue *q) |
860 | { | |
861 | struct blk_mq_hw_ctx *hctx; | |
862 | int i; | |
863 | ||
864 | queue_for_each_hw_ctx(q, hctx, i) | |
865 | blk_mq_start_hw_queue(hctx); | |
866 | } | |
867 | EXPORT_SYMBOL(blk_mq_start_hw_queues); | |
868 | ||
869 | ||
1b4a3258 | 870 | void blk_mq_start_stopped_hw_queues(struct request_queue *q, bool async) |
320ae51f JA |
871 | { |
872 | struct blk_mq_hw_ctx *hctx; | |
873 | int i; | |
874 | ||
875 | queue_for_each_hw_ctx(q, hctx, i) { | |
876 | if (!test_bit(BLK_MQ_S_STOPPED, &hctx->state)) | |
877 | continue; | |
878 | ||
879 | clear_bit(BLK_MQ_S_STOPPED, &hctx->state); | |
e4043dcf | 880 | preempt_disable(); |
1b4a3258 | 881 | blk_mq_run_hw_queue(hctx, async); |
e4043dcf | 882 | preempt_enable(); |
320ae51f JA |
883 | } |
884 | } | |
885 | EXPORT_SYMBOL(blk_mq_start_stopped_hw_queues); | |
886 | ||
70f4db63 | 887 | static void blk_mq_run_work_fn(struct work_struct *work) |
320ae51f JA |
888 | { |
889 | struct blk_mq_hw_ctx *hctx; | |
890 | ||
70f4db63 | 891 | hctx = container_of(work, struct blk_mq_hw_ctx, run_work.work); |
e4043dcf | 892 | |
320ae51f JA |
893 | __blk_mq_run_hw_queue(hctx); |
894 | } | |
895 | ||
70f4db63 CH |
896 | static void blk_mq_delay_work_fn(struct work_struct *work) |
897 | { | |
898 | struct blk_mq_hw_ctx *hctx; | |
899 | ||
900 | hctx = container_of(work, struct blk_mq_hw_ctx, delay_work.work); | |
901 | ||
902 | if (test_and_clear_bit(BLK_MQ_S_STOPPED, &hctx->state)) | |
903 | __blk_mq_run_hw_queue(hctx); | |
904 | } | |
905 | ||
906 | void blk_mq_delay_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs) | |
907 | { | |
908 | unsigned long tmo = msecs_to_jiffies(msecs); | |
909 | ||
910 | if (hctx->queue->nr_hw_queues == 1) | |
911 | kblockd_schedule_delayed_work(&hctx->delay_work, tmo); | |
912 | else { | |
913 | unsigned int cpu; | |
914 | ||
506e931f | 915 | cpu = blk_mq_hctx_next_cpu(hctx); |
70f4db63 CH |
916 | kblockd_schedule_delayed_work_on(cpu, &hctx->delay_work, tmo); |
917 | } | |
918 | } | |
919 | EXPORT_SYMBOL(blk_mq_delay_queue); | |
920 | ||
320ae51f | 921 | static void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, |
72a0a36e | 922 | struct request *rq, bool at_head) |
320ae51f JA |
923 | { |
924 | struct blk_mq_ctx *ctx = rq->mq_ctx; | |
925 | ||
01b983c9 JA |
926 | trace_block_rq_insert(hctx->queue, rq); |
927 | ||
72a0a36e CH |
928 | if (at_head) |
929 | list_add(&rq->queuelist, &ctx->rq_list); | |
930 | else | |
931 | list_add_tail(&rq->queuelist, &ctx->rq_list); | |
4bb659b1 | 932 | |
320ae51f | 933 | blk_mq_hctx_mark_pending(hctx, ctx); |
320ae51f JA |
934 | } |
935 | ||
eeabc850 CH |
936 | void blk_mq_insert_request(struct request *rq, bool at_head, bool run_queue, |
937 | bool async) | |
320ae51f | 938 | { |
eeabc850 | 939 | struct request_queue *q = rq->q; |
320ae51f | 940 | struct blk_mq_hw_ctx *hctx; |
eeabc850 CH |
941 | struct blk_mq_ctx *ctx = rq->mq_ctx, *current_ctx; |
942 | ||
943 | current_ctx = blk_mq_get_ctx(q); | |
944 | if (!cpu_online(ctx->cpu)) | |
945 | rq->mq_ctx = ctx = current_ctx; | |
320ae51f | 946 | |
320ae51f JA |
947 | hctx = q->mq_ops->map_queue(q, ctx->cpu); |
948 | ||
a57a178a CH |
949 | spin_lock(&ctx->lock); |
950 | __blk_mq_insert_request(hctx, rq, at_head); | |
951 | spin_unlock(&ctx->lock); | |
320ae51f | 952 | |
320ae51f JA |
953 | if (run_queue) |
954 | blk_mq_run_hw_queue(hctx, async); | |
e4043dcf JA |
955 | |
956 | blk_mq_put_ctx(current_ctx); | |
320ae51f JA |
957 | } |
958 | ||
959 | static void blk_mq_insert_requests(struct request_queue *q, | |
960 | struct blk_mq_ctx *ctx, | |
961 | struct list_head *list, | |
962 | int depth, | |
963 | bool from_schedule) | |
964 | ||
965 | { | |
966 | struct blk_mq_hw_ctx *hctx; | |
967 | struct blk_mq_ctx *current_ctx; | |
968 | ||
969 | trace_block_unplug(q, depth, !from_schedule); | |
970 | ||
971 | current_ctx = blk_mq_get_ctx(q); | |
972 | ||
973 | if (!cpu_online(ctx->cpu)) | |
974 | ctx = current_ctx; | |
975 | hctx = q->mq_ops->map_queue(q, ctx->cpu); | |
976 | ||
977 | /* | |
978 | * preemption doesn't flush plug list, so it's possible ctx->cpu is | |
979 | * offline now | |
980 | */ | |
981 | spin_lock(&ctx->lock); | |
982 | while (!list_empty(list)) { | |
983 | struct request *rq; | |
984 | ||
985 | rq = list_first_entry(list, struct request, queuelist); | |
986 | list_del_init(&rq->queuelist); | |
987 | rq->mq_ctx = ctx; | |
72a0a36e | 988 | __blk_mq_insert_request(hctx, rq, false); |
320ae51f JA |
989 | } |
990 | spin_unlock(&ctx->lock); | |
991 | ||
320ae51f | 992 | blk_mq_run_hw_queue(hctx, from_schedule); |
e4043dcf | 993 | blk_mq_put_ctx(current_ctx); |
320ae51f JA |
994 | } |
995 | ||
996 | static int plug_ctx_cmp(void *priv, struct list_head *a, struct list_head *b) | |
997 | { | |
998 | struct request *rqa = container_of(a, struct request, queuelist); | |
999 | struct request *rqb = container_of(b, struct request, queuelist); | |
1000 | ||
1001 | return !(rqa->mq_ctx < rqb->mq_ctx || | |
1002 | (rqa->mq_ctx == rqb->mq_ctx && | |
1003 | blk_rq_pos(rqa) < blk_rq_pos(rqb))); | |
1004 | } | |
1005 | ||
1006 | void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule) | |
1007 | { | |
1008 | struct blk_mq_ctx *this_ctx; | |
1009 | struct request_queue *this_q; | |
1010 | struct request *rq; | |
1011 | LIST_HEAD(list); | |
1012 | LIST_HEAD(ctx_list); | |
1013 | unsigned int depth; | |
1014 | ||
1015 | list_splice_init(&plug->mq_list, &list); | |
1016 | ||
1017 | list_sort(NULL, &list, plug_ctx_cmp); | |
1018 | ||
1019 | this_q = NULL; | |
1020 | this_ctx = NULL; | |
1021 | depth = 0; | |
1022 | ||
1023 | while (!list_empty(&list)) { | |
1024 | rq = list_entry_rq(list.next); | |
1025 | list_del_init(&rq->queuelist); | |
1026 | BUG_ON(!rq->q); | |
1027 | if (rq->mq_ctx != this_ctx) { | |
1028 | if (this_ctx) { | |
1029 | blk_mq_insert_requests(this_q, this_ctx, | |
1030 | &ctx_list, depth, | |
1031 | from_schedule); | |
1032 | } | |
1033 | ||
1034 | this_ctx = rq->mq_ctx; | |
1035 | this_q = rq->q; | |
1036 | depth = 0; | |
1037 | } | |
1038 | ||
1039 | depth++; | |
1040 | list_add_tail(&rq->queuelist, &ctx_list); | |
1041 | } | |
1042 | ||
1043 | /* | |
1044 | * If 'this_ctx' is set, we know we have entries to complete | |
1045 | * on 'ctx_list'. Do those. | |
1046 | */ | |
1047 | if (this_ctx) { | |
1048 | blk_mq_insert_requests(this_q, this_ctx, &ctx_list, depth, | |
1049 | from_schedule); | |
1050 | } | |
1051 | } | |
1052 | ||
1053 | static void blk_mq_bio_to_request(struct request *rq, struct bio *bio) | |
1054 | { | |
1055 | init_request_from_bio(rq, bio); | |
4b570521 | 1056 | |
3ee32372 | 1057 | if (blk_do_io_stat(rq)) |
4b570521 | 1058 | blk_account_io_start(rq, 1); |
320ae51f JA |
1059 | } |
1060 | ||
274a5843 JA |
1061 | static inline bool hctx_allow_merges(struct blk_mq_hw_ctx *hctx) |
1062 | { | |
1063 | return (hctx->flags & BLK_MQ_F_SHOULD_MERGE) && | |
1064 | !blk_queue_nomerges(hctx->queue); | |
1065 | } | |
1066 | ||
07068d5b JA |
1067 | static inline bool blk_mq_merge_queue_io(struct blk_mq_hw_ctx *hctx, |
1068 | struct blk_mq_ctx *ctx, | |
1069 | struct request *rq, struct bio *bio) | |
320ae51f | 1070 | { |
274a5843 | 1071 | if (!hctx_allow_merges(hctx)) { |
07068d5b JA |
1072 | blk_mq_bio_to_request(rq, bio); |
1073 | spin_lock(&ctx->lock); | |
1074 | insert_rq: | |
1075 | __blk_mq_insert_request(hctx, rq, false); | |
1076 | spin_unlock(&ctx->lock); | |
1077 | return false; | |
1078 | } else { | |
274a5843 JA |
1079 | struct request_queue *q = hctx->queue; |
1080 | ||
07068d5b JA |
1081 | spin_lock(&ctx->lock); |
1082 | if (!blk_mq_attempt_merge(q, ctx, bio)) { | |
1083 | blk_mq_bio_to_request(rq, bio); | |
1084 | goto insert_rq; | |
1085 | } | |
320ae51f | 1086 | |
07068d5b JA |
1087 | spin_unlock(&ctx->lock); |
1088 | __blk_mq_free_request(hctx, ctx, rq); | |
1089 | return true; | |
14ec77f3 | 1090 | } |
07068d5b | 1091 | } |
14ec77f3 | 1092 | |
07068d5b JA |
1093 | struct blk_map_ctx { |
1094 | struct blk_mq_hw_ctx *hctx; | |
1095 | struct blk_mq_ctx *ctx; | |
1096 | }; | |
1097 | ||
1098 | static struct request *blk_mq_map_request(struct request_queue *q, | |
1099 | struct bio *bio, | |
1100 | struct blk_map_ctx *data) | |
1101 | { | |
1102 | struct blk_mq_hw_ctx *hctx; | |
1103 | struct blk_mq_ctx *ctx; | |
1104 | struct request *rq; | |
1105 | int rw = bio_data_dir(bio); | |
cb96a42c | 1106 | struct blk_mq_alloc_data alloc_data; |
320ae51f | 1107 | |
07068d5b | 1108 | if (unlikely(blk_mq_queue_enter(q))) { |
320ae51f | 1109 | bio_endio(bio, -EIO); |
07068d5b | 1110 | return NULL; |
320ae51f JA |
1111 | } |
1112 | ||
1113 | ctx = blk_mq_get_ctx(q); | |
1114 | hctx = q->mq_ops->map_queue(q, ctx->cpu); | |
1115 | ||
07068d5b | 1116 | if (rw_is_sync(bio->bi_rw)) |
27fbf4e8 | 1117 | rw |= REQ_SYNC; |
07068d5b | 1118 | |
320ae51f | 1119 | trace_block_getrq(q, bio, rw); |
cb96a42c ML |
1120 | blk_mq_set_alloc_data(&alloc_data, q, GFP_ATOMIC, false, ctx, |
1121 | hctx); | |
1122 | rq = __blk_mq_alloc_request(&alloc_data, rw); | |
5dee8577 | 1123 | if (unlikely(!rq)) { |
793597a6 | 1124 | __blk_mq_run_hw_queue(hctx); |
320ae51f JA |
1125 | blk_mq_put_ctx(ctx); |
1126 | trace_block_sleeprq(q, bio, rw); | |
793597a6 CH |
1127 | |
1128 | ctx = blk_mq_get_ctx(q); | |
320ae51f | 1129 | hctx = q->mq_ops->map_queue(q, ctx->cpu); |
cb96a42c ML |
1130 | blk_mq_set_alloc_data(&alloc_data, q, |
1131 | __GFP_WAIT|GFP_ATOMIC, false, ctx, hctx); | |
1132 | rq = __blk_mq_alloc_request(&alloc_data, rw); | |
1133 | ctx = alloc_data.ctx; | |
1134 | hctx = alloc_data.hctx; | |
320ae51f JA |
1135 | } |
1136 | ||
1137 | hctx->queued++; | |
07068d5b JA |
1138 | data->hctx = hctx; |
1139 | data->ctx = ctx; | |
1140 | return rq; | |
1141 | } | |
1142 | ||
1143 | /* | |
1144 | * Multiple hardware queue variant. This will not use per-process plugs, | |
1145 | * but will attempt to bypass the hctx queueing if we can go straight to | |
1146 | * hardware for SYNC IO. | |
1147 | */ | |
1148 | static void blk_mq_make_request(struct request_queue *q, struct bio *bio) | |
1149 | { | |
1150 | const int is_sync = rw_is_sync(bio->bi_rw); | |
1151 | const int is_flush_fua = bio->bi_rw & (REQ_FLUSH | REQ_FUA); | |
1152 | struct blk_map_ctx data; | |
1153 | struct request *rq; | |
1154 | ||
1155 | blk_queue_bounce(q, &bio); | |
1156 | ||
1157 | if (bio_integrity_enabled(bio) && bio_integrity_prep(bio)) { | |
1158 | bio_endio(bio, -EIO); | |
1159 | return; | |
1160 | } | |
1161 | ||
1162 | rq = blk_mq_map_request(q, bio, &data); | |
1163 | if (unlikely(!rq)) | |
1164 | return; | |
1165 | ||
1166 | if (unlikely(is_flush_fua)) { | |
1167 | blk_mq_bio_to_request(rq, bio); | |
1168 | blk_insert_flush(rq); | |
1169 | goto run_queue; | |
1170 | } | |
1171 | ||
1172 | if (is_sync) { | |
1173 | int ret; | |
1174 | ||
1175 | blk_mq_bio_to_request(rq, bio); | |
07068d5b JA |
1176 | |
1177 | /* | |
1178 | * For OK queue, we are done. For error, kill it. Any other | |
1179 | * error (busy), just add it to our list as we previously | |
1180 | * would have done | |
1181 | */ | |
bf572297 | 1182 | ret = q->mq_ops->queue_rq(data.hctx, rq, true); |
07068d5b JA |
1183 | if (ret == BLK_MQ_RQ_QUEUE_OK) |
1184 | goto done; | |
1185 | else { | |
1186 | __blk_mq_requeue_request(rq); | |
1187 | ||
1188 | if (ret == BLK_MQ_RQ_QUEUE_ERROR) { | |
1189 | rq->errors = -EIO; | |
c8a446ad | 1190 | blk_mq_end_request(rq, rq->errors); |
07068d5b JA |
1191 | goto done; |
1192 | } | |
1193 | } | |
1194 | } | |
1195 | ||
1196 | if (!blk_mq_merge_queue_io(data.hctx, data.ctx, rq, bio)) { | |
1197 | /* | |
1198 | * For a SYNC request, send it to the hardware immediately. For | |
1199 | * an ASYNC request, just ensure that we run it later on. The | |
1200 | * latter allows for merging opportunities and more efficient | |
1201 | * dispatching. | |
1202 | */ | |
1203 | run_queue: | |
1204 | blk_mq_run_hw_queue(data.hctx, !is_sync || is_flush_fua); | |
1205 | } | |
1206 | done: | |
1207 | blk_mq_put_ctx(data.ctx); | |
1208 | } | |
1209 | ||
1210 | /* | |
1211 | * Single hardware queue variant. This will attempt to use any per-process | |
1212 | * plug for merging and IO deferral. | |
1213 | */ | |
1214 | static void blk_sq_make_request(struct request_queue *q, struct bio *bio) | |
1215 | { | |
1216 | const int is_sync = rw_is_sync(bio->bi_rw); | |
1217 | const int is_flush_fua = bio->bi_rw & (REQ_FLUSH | REQ_FUA); | |
1218 | unsigned int use_plug, request_count = 0; | |
1219 | struct blk_map_ctx data; | |
1220 | struct request *rq; | |
1221 | ||
1222 | /* | |
1223 | * If we have multiple hardware queues, just go directly to | |
1224 | * one of those for sync IO. | |
1225 | */ | |
1226 | use_plug = !is_flush_fua && !is_sync; | |
1227 | ||
1228 | blk_queue_bounce(q, &bio); | |
1229 | ||
1230 | if (bio_integrity_enabled(bio) && bio_integrity_prep(bio)) { | |
1231 | bio_endio(bio, -EIO); | |
1232 | return; | |
1233 | } | |
1234 | ||
1235 | if (use_plug && !blk_queue_nomerges(q) && | |
1236 | blk_attempt_plug_merge(q, bio, &request_count)) | |
1237 | return; | |
1238 | ||
1239 | rq = blk_mq_map_request(q, bio, &data); | |
ff87bcec JA |
1240 | if (unlikely(!rq)) |
1241 | return; | |
320ae51f JA |
1242 | |
1243 | if (unlikely(is_flush_fua)) { | |
1244 | blk_mq_bio_to_request(rq, bio); | |
320ae51f JA |
1245 | blk_insert_flush(rq); |
1246 | goto run_queue; | |
1247 | } | |
1248 | ||
1249 | /* | |
1250 | * A task plug currently exists. Since this is completely lockless, | |
1251 | * utilize that to temporarily store requests until the task is | |
1252 | * either done or scheduled away. | |
1253 | */ | |
1254 | if (use_plug) { | |
1255 | struct blk_plug *plug = current->plug; | |
1256 | ||
1257 | if (plug) { | |
1258 | blk_mq_bio_to_request(rq, bio); | |
92f399c7 | 1259 | if (list_empty(&plug->mq_list)) |
320ae51f JA |
1260 | trace_block_plug(q); |
1261 | else if (request_count >= BLK_MAX_REQUEST_COUNT) { | |
1262 | blk_flush_plug_list(plug, false); | |
1263 | trace_block_plug(q); | |
1264 | } | |
1265 | list_add_tail(&rq->queuelist, &plug->mq_list); | |
07068d5b | 1266 | blk_mq_put_ctx(data.ctx); |
320ae51f JA |
1267 | return; |
1268 | } | |
1269 | } | |
1270 | ||
07068d5b JA |
1271 | if (!blk_mq_merge_queue_io(data.hctx, data.ctx, rq, bio)) { |
1272 | /* | |
1273 | * For a SYNC request, send it to the hardware immediately. For | |
1274 | * an ASYNC request, just ensure that we run it later on. The | |
1275 | * latter allows for merging opportunities and more efficient | |
1276 | * dispatching. | |
1277 | */ | |
1278 | run_queue: | |
1279 | blk_mq_run_hw_queue(data.hctx, !is_sync || is_flush_fua); | |
320ae51f JA |
1280 | } |
1281 | ||
07068d5b | 1282 | blk_mq_put_ctx(data.ctx); |
320ae51f JA |
1283 | } |
1284 | ||
1285 | /* | |
1286 | * Default mapping to a software queue, since we use one per CPU. | |
1287 | */ | |
1288 | struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q, const int cpu) | |
1289 | { | |
1290 | return q->queue_hw_ctx[q->mq_map[cpu]]; | |
1291 | } | |
1292 | EXPORT_SYMBOL(blk_mq_map_queue); | |
1293 | ||
24d2f903 CH |
1294 | static void blk_mq_free_rq_map(struct blk_mq_tag_set *set, |
1295 | struct blk_mq_tags *tags, unsigned int hctx_idx) | |
95363efd | 1296 | { |
e9b267d9 | 1297 | struct page *page; |
320ae51f | 1298 | |
24d2f903 | 1299 | if (tags->rqs && set->ops->exit_request) { |
e9b267d9 | 1300 | int i; |
320ae51f | 1301 | |
24d2f903 CH |
1302 | for (i = 0; i < tags->nr_tags; i++) { |
1303 | if (!tags->rqs[i]) | |
e9b267d9 | 1304 | continue; |
24d2f903 CH |
1305 | set->ops->exit_request(set->driver_data, tags->rqs[i], |
1306 | hctx_idx, i); | |
a5164405 | 1307 | tags->rqs[i] = NULL; |
e9b267d9 | 1308 | } |
320ae51f | 1309 | } |
320ae51f | 1310 | |
24d2f903 CH |
1311 | while (!list_empty(&tags->page_list)) { |
1312 | page = list_first_entry(&tags->page_list, struct page, lru); | |
6753471c | 1313 | list_del_init(&page->lru); |
320ae51f JA |
1314 | __free_pages(page, page->private); |
1315 | } | |
1316 | ||
24d2f903 | 1317 | kfree(tags->rqs); |
320ae51f | 1318 | |
24d2f903 | 1319 | blk_mq_free_tags(tags); |
320ae51f JA |
1320 | } |
1321 | ||
1322 | static size_t order_to_size(unsigned int order) | |
1323 | { | |
4ca08500 | 1324 | return (size_t)PAGE_SIZE << order; |
320ae51f JA |
1325 | } |
1326 | ||
24d2f903 CH |
1327 | static struct blk_mq_tags *blk_mq_init_rq_map(struct blk_mq_tag_set *set, |
1328 | unsigned int hctx_idx) | |
320ae51f | 1329 | { |
24d2f903 | 1330 | struct blk_mq_tags *tags; |
320ae51f JA |
1331 | unsigned int i, j, entries_per_page, max_order = 4; |
1332 | size_t rq_size, left; | |
1333 | ||
24d2f903 CH |
1334 | tags = blk_mq_init_tags(set->queue_depth, set->reserved_tags, |
1335 | set->numa_node); | |
1336 | if (!tags) | |
1337 | return NULL; | |
320ae51f | 1338 | |
24d2f903 CH |
1339 | INIT_LIST_HEAD(&tags->page_list); |
1340 | ||
a5164405 JA |
1341 | tags->rqs = kzalloc_node(set->queue_depth * sizeof(struct request *), |
1342 | GFP_KERNEL | __GFP_NOWARN | __GFP_NORETRY, | |
1343 | set->numa_node); | |
24d2f903 CH |
1344 | if (!tags->rqs) { |
1345 | blk_mq_free_tags(tags); | |
1346 | return NULL; | |
1347 | } | |
320ae51f JA |
1348 | |
1349 | /* | |
1350 | * rq_size is the size of the request plus driver payload, rounded | |
1351 | * to the cacheline size | |
1352 | */ | |
24d2f903 | 1353 | rq_size = round_up(sizeof(struct request) + set->cmd_size, |
320ae51f | 1354 | cache_line_size()); |
24d2f903 | 1355 | left = rq_size * set->queue_depth; |
320ae51f | 1356 | |
24d2f903 | 1357 | for (i = 0; i < set->queue_depth; ) { |
320ae51f JA |
1358 | int this_order = max_order; |
1359 | struct page *page; | |
1360 | int to_do; | |
1361 | void *p; | |
1362 | ||
1363 | while (left < order_to_size(this_order - 1) && this_order) | |
1364 | this_order--; | |
1365 | ||
1366 | do { | |
a5164405 JA |
1367 | page = alloc_pages_node(set->numa_node, |
1368 | GFP_KERNEL | __GFP_NOWARN | __GFP_NORETRY, | |
1369 | this_order); | |
320ae51f JA |
1370 | if (page) |
1371 | break; | |
1372 | if (!this_order--) | |
1373 | break; | |
1374 | if (order_to_size(this_order) < rq_size) | |
1375 | break; | |
1376 | } while (1); | |
1377 | ||
1378 | if (!page) | |
24d2f903 | 1379 | goto fail; |
320ae51f JA |
1380 | |
1381 | page->private = this_order; | |
24d2f903 | 1382 | list_add_tail(&page->lru, &tags->page_list); |
320ae51f JA |
1383 | |
1384 | p = page_address(page); | |
1385 | entries_per_page = order_to_size(this_order) / rq_size; | |
24d2f903 | 1386 | to_do = min(entries_per_page, set->queue_depth - i); |
320ae51f JA |
1387 | left -= to_do * rq_size; |
1388 | for (j = 0; j < to_do; j++) { | |
24d2f903 | 1389 | tags->rqs[i] = p; |
683d0e12 DH |
1390 | tags->rqs[i]->atomic_flags = 0; |
1391 | tags->rqs[i]->cmd_flags = 0; | |
24d2f903 CH |
1392 | if (set->ops->init_request) { |
1393 | if (set->ops->init_request(set->driver_data, | |
1394 | tags->rqs[i], hctx_idx, i, | |
a5164405 JA |
1395 | set->numa_node)) { |
1396 | tags->rqs[i] = NULL; | |
24d2f903 | 1397 | goto fail; |
a5164405 | 1398 | } |
e9b267d9 CH |
1399 | } |
1400 | ||
320ae51f JA |
1401 | p += rq_size; |
1402 | i++; | |
1403 | } | |
1404 | } | |
1405 | ||
24d2f903 | 1406 | return tags; |
320ae51f | 1407 | |
24d2f903 | 1408 | fail: |
24d2f903 CH |
1409 | blk_mq_free_rq_map(set, tags, hctx_idx); |
1410 | return NULL; | |
320ae51f JA |
1411 | } |
1412 | ||
1429d7c9 JA |
1413 | static void blk_mq_free_bitmap(struct blk_mq_ctxmap *bitmap) |
1414 | { | |
1415 | kfree(bitmap->map); | |
1416 | } | |
1417 | ||
1418 | static int blk_mq_alloc_bitmap(struct blk_mq_ctxmap *bitmap, int node) | |
1419 | { | |
1420 | unsigned int bpw = 8, total, num_maps, i; | |
1421 | ||
1422 | bitmap->bits_per_word = bpw; | |
1423 | ||
1424 | num_maps = ALIGN(nr_cpu_ids, bpw) / bpw; | |
1425 | bitmap->map = kzalloc_node(num_maps * sizeof(struct blk_align_bitmap), | |
1426 | GFP_KERNEL, node); | |
1427 | if (!bitmap->map) | |
1428 | return -ENOMEM; | |
1429 | ||
1430 | bitmap->map_size = num_maps; | |
1431 | ||
1432 | total = nr_cpu_ids; | |
1433 | for (i = 0; i < num_maps; i++) { | |
1434 | bitmap->map[i].depth = min(total, bitmap->bits_per_word); | |
1435 | total -= bitmap->map[i].depth; | |
1436 | } | |
1437 | ||
1438 | return 0; | |
1439 | } | |
1440 | ||
484b4061 JA |
1441 | static int blk_mq_hctx_cpu_offline(struct blk_mq_hw_ctx *hctx, int cpu) |
1442 | { | |
1443 | struct request_queue *q = hctx->queue; | |
1444 | struct blk_mq_ctx *ctx; | |
1445 | LIST_HEAD(tmp); | |
1446 | ||
1447 | /* | |
1448 | * Move ctx entries to new CPU, if this one is going away. | |
1449 | */ | |
1450 | ctx = __blk_mq_get_ctx(q, cpu); | |
1451 | ||
1452 | spin_lock(&ctx->lock); | |
1453 | if (!list_empty(&ctx->rq_list)) { | |
1454 | list_splice_init(&ctx->rq_list, &tmp); | |
1455 | blk_mq_hctx_clear_pending(hctx, ctx); | |
1456 | } | |
1457 | spin_unlock(&ctx->lock); | |
1458 | ||
1459 | if (list_empty(&tmp)) | |
1460 | return NOTIFY_OK; | |
1461 | ||
1462 | ctx = blk_mq_get_ctx(q); | |
1463 | spin_lock(&ctx->lock); | |
1464 | ||
1465 | while (!list_empty(&tmp)) { | |
1466 | struct request *rq; | |
1467 | ||
1468 | rq = list_first_entry(&tmp, struct request, queuelist); | |
1469 | rq->mq_ctx = ctx; | |
1470 | list_move_tail(&rq->queuelist, &ctx->rq_list); | |
1471 | } | |
1472 | ||
1473 | hctx = q->mq_ops->map_queue(q, ctx->cpu); | |
1474 | blk_mq_hctx_mark_pending(hctx, ctx); | |
1475 | ||
1476 | spin_unlock(&ctx->lock); | |
1477 | ||
1478 | blk_mq_run_hw_queue(hctx, true); | |
1479 | blk_mq_put_ctx(ctx); | |
1480 | return NOTIFY_OK; | |
1481 | } | |
1482 | ||
1483 | static int blk_mq_hctx_cpu_online(struct blk_mq_hw_ctx *hctx, int cpu) | |
1484 | { | |
1485 | struct request_queue *q = hctx->queue; | |
1486 | struct blk_mq_tag_set *set = q->tag_set; | |
1487 | ||
1488 | if (set->tags[hctx->queue_num]) | |
1489 | return NOTIFY_OK; | |
1490 | ||
1491 | set->tags[hctx->queue_num] = blk_mq_init_rq_map(set, hctx->queue_num); | |
1492 | if (!set->tags[hctx->queue_num]) | |
1493 | return NOTIFY_STOP; | |
1494 | ||
1495 | hctx->tags = set->tags[hctx->queue_num]; | |
1496 | return NOTIFY_OK; | |
1497 | } | |
1498 | ||
1499 | static int blk_mq_hctx_notify(void *data, unsigned long action, | |
1500 | unsigned int cpu) | |
1501 | { | |
1502 | struct blk_mq_hw_ctx *hctx = data; | |
1503 | ||
1504 | if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) | |
1505 | return blk_mq_hctx_cpu_offline(hctx, cpu); | |
1506 | else if (action == CPU_ONLINE || action == CPU_ONLINE_FROZEN) | |
1507 | return blk_mq_hctx_cpu_online(hctx, cpu); | |
1508 | ||
1509 | return NOTIFY_OK; | |
1510 | } | |
1511 | ||
624dbe47 ML |
1512 | static void blk_mq_exit_hw_queues(struct request_queue *q, |
1513 | struct blk_mq_tag_set *set, int nr_queue) | |
1514 | { | |
1515 | struct blk_mq_hw_ctx *hctx; | |
1516 | unsigned int i; | |
1517 | ||
1518 | queue_for_each_hw_ctx(q, hctx, i) { | |
1519 | if (i == nr_queue) | |
1520 | break; | |
1521 | ||
f899fed4 JA |
1522 | blk_mq_tag_idle(hctx); |
1523 | ||
624dbe47 ML |
1524 | if (set->ops->exit_hctx) |
1525 | set->ops->exit_hctx(hctx, i); | |
1526 | ||
1527 | blk_mq_unregister_cpu_notifier(&hctx->cpu_notifier); | |
1528 | kfree(hctx->ctxs); | |
1529 | blk_mq_free_bitmap(&hctx->ctx_map); | |
1530 | } | |
1531 | ||
1532 | } | |
1533 | ||
1534 | static void blk_mq_free_hw_queues(struct request_queue *q, | |
1535 | struct blk_mq_tag_set *set) | |
1536 | { | |
1537 | struct blk_mq_hw_ctx *hctx; | |
1538 | unsigned int i; | |
1539 | ||
1540 | queue_for_each_hw_ctx(q, hctx, i) { | |
1541 | free_cpumask_var(hctx->cpumask); | |
cdef54dd | 1542 | kfree(hctx); |
624dbe47 ML |
1543 | } |
1544 | } | |
1545 | ||
320ae51f | 1546 | static int blk_mq_init_hw_queues(struct request_queue *q, |
24d2f903 | 1547 | struct blk_mq_tag_set *set) |
320ae51f JA |
1548 | { |
1549 | struct blk_mq_hw_ctx *hctx; | |
624dbe47 | 1550 | unsigned int i; |
320ae51f JA |
1551 | |
1552 | /* | |
1553 | * Initialize hardware queues | |
1554 | */ | |
1555 | queue_for_each_hw_ctx(q, hctx, i) { | |
320ae51f JA |
1556 | int node; |
1557 | ||
1558 | node = hctx->numa_node; | |
1559 | if (node == NUMA_NO_NODE) | |
24d2f903 | 1560 | node = hctx->numa_node = set->numa_node; |
320ae51f | 1561 | |
70f4db63 CH |
1562 | INIT_DELAYED_WORK(&hctx->run_work, blk_mq_run_work_fn); |
1563 | INIT_DELAYED_WORK(&hctx->delay_work, blk_mq_delay_work_fn); | |
320ae51f JA |
1564 | spin_lock_init(&hctx->lock); |
1565 | INIT_LIST_HEAD(&hctx->dispatch); | |
1566 | hctx->queue = q; | |
1567 | hctx->queue_num = i; | |
24d2f903 CH |
1568 | hctx->flags = set->flags; |
1569 | hctx->cmd_size = set->cmd_size; | |
320ae51f JA |
1570 | |
1571 | blk_mq_init_cpu_notifier(&hctx->cpu_notifier, | |
1572 | blk_mq_hctx_notify, hctx); | |
1573 | blk_mq_register_cpu_notifier(&hctx->cpu_notifier); | |
1574 | ||
24d2f903 | 1575 | hctx->tags = set->tags[i]; |
320ae51f JA |
1576 | |
1577 | /* | |
a68aafa5 | 1578 | * Allocate space for all possible cpus to avoid allocation at |
320ae51f JA |
1579 | * runtime |
1580 | */ | |
1581 | hctx->ctxs = kmalloc_node(nr_cpu_ids * sizeof(void *), | |
1582 | GFP_KERNEL, node); | |
1583 | if (!hctx->ctxs) | |
1584 | break; | |
1585 | ||
1429d7c9 | 1586 | if (blk_mq_alloc_bitmap(&hctx->ctx_map, node)) |
320ae51f JA |
1587 | break; |
1588 | ||
320ae51f JA |
1589 | hctx->nr_ctx = 0; |
1590 | ||
24d2f903 CH |
1591 | if (set->ops->init_hctx && |
1592 | set->ops->init_hctx(hctx, set->driver_data, i)) | |
320ae51f JA |
1593 | break; |
1594 | } | |
1595 | ||
1596 | if (i == q->nr_hw_queues) | |
1597 | return 0; | |
1598 | ||
1599 | /* | |
1600 | * Init failed | |
1601 | */ | |
624dbe47 | 1602 | blk_mq_exit_hw_queues(q, set, i); |
320ae51f JA |
1603 | |
1604 | return 1; | |
1605 | } | |
1606 | ||
1607 | static void blk_mq_init_cpu_queues(struct request_queue *q, | |
1608 | unsigned int nr_hw_queues) | |
1609 | { | |
1610 | unsigned int i; | |
1611 | ||
1612 | for_each_possible_cpu(i) { | |
1613 | struct blk_mq_ctx *__ctx = per_cpu_ptr(q->queue_ctx, i); | |
1614 | struct blk_mq_hw_ctx *hctx; | |
1615 | ||
1616 | memset(__ctx, 0, sizeof(*__ctx)); | |
1617 | __ctx->cpu = i; | |
1618 | spin_lock_init(&__ctx->lock); | |
1619 | INIT_LIST_HEAD(&__ctx->rq_list); | |
1620 | __ctx->queue = q; | |
1621 | ||
1622 | /* If the cpu isn't online, the cpu is mapped to first hctx */ | |
320ae51f JA |
1623 | if (!cpu_online(i)) |
1624 | continue; | |
1625 | ||
e4043dcf JA |
1626 | hctx = q->mq_ops->map_queue(q, i); |
1627 | cpumask_set_cpu(i, hctx->cpumask); | |
1628 | hctx->nr_ctx++; | |
1629 | ||
320ae51f JA |
1630 | /* |
1631 | * Set local node, IFF we have more than one hw queue. If | |
1632 | * not, we remain on the home node of the device | |
1633 | */ | |
1634 | if (nr_hw_queues > 1 && hctx->numa_node == NUMA_NO_NODE) | |
1635 | hctx->numa_node = cpu_to_node(i); | |
1636 | } | |
1637 | } | |
1638 | ||
1639 | static void blk_mq_map_swqueue(struct request_queue *q) | |
1640 | { | |
1641 | unsigned int i; | |
1642 | struct blk_mq_hw_ctx *hctx; | |
1643 | struct blk_mq_ctx *ctx; | |
1644 | ||
1645 | queue_for_each_hw_ctx(q, hctx, i) { | |
e4043dcf | 1646 | cpumask_clear(hctx->cpumask); |
320ae51f JA |
1647 | hctx->nr_ctx = 0; |
1648 | } | |
1649 | ||
1650 | /* | |
1651 | * Map software to hardware queues | |
1652 | */ | |
1653 | queue_for_each_ctx(q, ctx, i) { | |
1654 | /* If the cpu isn't online, the cpu is mapped to first hctx */ | |
e4043dcf JA |
1655 | if (!cpu_online(i)) |
1656 | continue; | |
1657 | ||
320ae51f | 1658 | hctx = q->mq_ops->map_queue(q, i); |
e4043dcf | 1659 | cpumask_set_cpu(i, hctx->cpumask); |
320ae51f JA |
1660 | ctx->index_hw = hctx->nr_ctx; |
1661 | hctx->ctxs[hctx->nr_ctx++] = ctx; | |
1662 | } | |
506e931f JA |
1663 | |
1664 | queue_for_each_hw_ctx(q, hctx, i) { | |
484b4061 | 1665 | /* |
a68aafa5 JA |
1666 | * If no software queues are mapped to this hardware queue, |
1667 | * disable it and free the request entries. | |
484b4061 JA |
1668 | */ |
1669 | if (!hctx->nr_ctx) { | |
1670 | struct blk_mq_tag_set *set = q->tag_set; | |
1671 | ||
1672 | if (set->tags[i]) { | |
1673 | blk_mq_free_rq_map(set, set->tags[i], i); | |
1674 | set->tags[i] = NULL; | |
1675 | hctx->tags = NULL; | |
1676 | } | |
1677 | continue; | |
1678 | } | |
1679 | ||
1680 | /* | |
1681 | * Initialize batch roundrobin counts | |
1682 | */ | |
506e931f JA |
1683 | hctx->next_cpu = cpumask_first(hctx->cpumask); |
1684 | hctx->next_cpu_batch = BLK_MQ_CPU_WORK_BATCH; | |
1685 | } | |
320ae51f JA |
1686 | } |
1687 | ||
0d2602ca JA |
1688 | static void blk_mq_update_tag_set_depth(struct blk_mq_tag_set *set) |
1689 | { | |
1690 | struct blk_mq_hw_ctx *hctx; | |
1691 | struct request_queue *q; | |
1692 | bool shared; | |
1693 | int i; | |
1694 | ||
1695 | if (set->tag_list.next == set->tag_list.prev) | |
1696 | shared = false; | |
1697 | else | |
1698 | shared = true; | |
1699 | ||
1700 | list_for_each_entry(q, &set->tag_list, tag_set_list) { | |
1701 | blk_mq_freeze_queue(q); | |
1702 | ||
1703 | queue_for_each_hw_ctx(q, hctx, i) { | |
1704 | if (shared) | |
1705 | hctx->flags |= BLK_MQ_F_TAG_SHARED; | |
1706 | else | |
1707 | hctx->flags &= ~BLK_MQ_F_TAG_SHARED; | |
1708 | } | |
1709 | blk_mq_unfreeze_queue(q); | |
1710 | } | |
1711 | } | |
1712 | ||
1713 | static void blk_mq_del_queue_tag_set(struct request_queue *q) | |
1714 | { | |
1715 | struct blk_mq_tag_set *set = q->tag_set; | |
1716 | ||
0d2602ca JA |
1717 | mutex_lock(&set->tag_list_lock); |
1718 | list_del_init(&q->tag_set_list); | |
1719 | blk_mq_update_tag_set_depth(set); | |
1720 | mutex_unlock(&set->tag_list_lock); | |
0d2602ca JA |
1721 | } |
1722 | ||
1723 | static void blk_mq_add_queue_tag_set(struct blk_mq_tag_set *set, | |
1724 | struct request_queue *q) | |
1725 | { | |
1726 | q->tag_set = set; | |
1727 | ||
1728 | mutex_lock(&set->tag_list_lock); | |
1729 | list_add_tail(&q->tag_set_list, &set->tag_list); | |
1730 | blk_mq_update_tag_set_depth(set); | |
1731 | mutex_unlock(&set->tag_list_lock); | |
1732 | } | |
1733 | ||
24d2f903 | 1734 | struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *set) |
320ae51f JA |
1735 | { |
1736 | struct blk_mq_hw_ctx **hctxs; | |
e6cdb092 | 1737 | struct blk_mq_ctx __percpu *ctx; |
320ae51f | 1738 | struct request_queue *q; |
f14bbe77 | 1739 | unsigned int *map; |
320ae51f JA |
1740 | int i; |
1741 | ||
320ae51f JA |
1742 | ctx = alloc_percpu(struct blk_mq_ctx); |
1743 | if (!ctx) | |
1744 | return ERR_PTR(-ENOMEM); | |
1745 | ||
aedcd72f JA |
1746 | /* |
1747 | * If a crashdump is active, then we are potentially in a very | |
1748 | * memory constrained environment. Limit us to 1 queue and | |
1749 | * 64 tags to prevent using too much memory. | |
1750 | */ | |
1751 | if (is_kdump_kernel()) { | |
1752 | set->nr_hw_queues = 1; | |
1753 | set->queue_depth = min(64U, set->queue_depth); | |
1754 | } | |
1755 | ||
24d2f903 CH |
1756 | hctxs = kmalloc_node(set->nr_hw_queues * sizeof(*hctxs), GFP_KERNEL, |
1757 | set->numa_node); | |
320ae51f JA |
1758 | |
1759 | if (!hctxs) | |
1760 | goto err_percpu; | |
1761 | ||
f14bbe77 JA |
1762 | map = blk_mq_make_queue_map(set); |
1763 | if (!map) | |
1764 | goto err_map; | |
1765 | ||
24d2f903 | 1766 | for (i = 0; i < set->nr_hw_queues; i++) { |
f14bbe77 JA |
1767 | int node = blk_mq_hw_queue_to_node(map, i); |
1768 | ||
cdef54dd CH |
1769 | hctxs[i] = kzalloc_node(sizeof(struct blk_mq_hw_ctx), |
1770 | GFP_KERNEL, node); | |
320ae51f JA |
1771 | if (!hctxs[i]) |
1772 | goto err_hctxs; | |
1773 | ||
e4043dcf JA |
1774 | if (!zalloc_cpumask_var(&hctxs[i]->cpumask, GFP_KERNEL)) |
1775 | goto err_hctxs; | |
1776 | ||
0d2602ca | 1777 | atomic_set(&hctxs[i]->nr_active, 0); |
f14bbe77 | 1778 | hctxs[i]->numa_node = node; |
320ae51f JA |
1779 | hctxs[i]->queue_num = i; |
1780 | } | |
1781 | ||
24d2f903 | 1782 | q = blk_alloc_queue_node(GFP_KERNEL, set->numa_node); |
320ae51f JA |
1783 | if (!q) |
1784 | goto err_hctxs; | |
1785 | ||
add703fd | 1786 | if (percpu_ref_init(&q->mq_usage_counter, blk_mq_usage_counter_release)) |
3d2936f4 ML |
1787 | goto err_map; |
1788 | ||
320ae51f JA |
1789 | setup_timer(&q->timeout, blk_mq_rq_timer, (unsigned long) q); |
1790 | blk_queue_rq_timeout(q, 30000); | |
1791 | ||
1792 | q->nr_queues = nr_cpu_ids; | |
24d2f903 | 1793 | q->nr_hw_queues = set->nr_hw_queues; |
f14bbe77 | 1794 | q->mq_map = map; |
320ae51f JA |
1795 | |
1796 | q->queue_ctx = ctx; | |
1797 | q->queue_hw_ctx = hctxs; | |
1798 | ||
24d2f903 | 1799 | q->mq_ops = set->ops; |
94eddfbe | 1800 | q->queue_flags |= QUEUE_FLAG_MQ_DEFAULT; |
320ae51f | 1801 | |
05f1dd53 JA |
1802 | if (!(set->flags & BLK_MQ_F_SG_MERGE)) |
1803 | q->queue_flags |= 1 << QUEUE_FLAG_NO_SG_MERGE; | |
1804 | ||
1be036e9 CH |
1805 | q->sg_reserved_size = INT_MAX; |
1806 | ||
6fca6a61 CH |
1807 | INIT_WORK(&q->requeue_work, blk_mq_requeue_work); |
1808 | INIT_LIST_HEAD(&q->requeue_list); | |
1809 | spin_lock_init(&q->requeue_lock); | |
1810 | ||
07068d5b JA |
1811 | if (q->nr_hw_queues > 1) |
1812 | blk_queue_make_request(q, blk_mq_make_request); | |
1813 | else | |
1814 | blk_queue_make_request(q, blk_sq_make_request); | |
1815 | ||
24d2f903 CH |
1816 | if (set->timeout) |
1817 | blk_queue_rq_timeout(q, set->timeout); | |
320ae51f | 1818 | |
eba71768 JA |
1819 | /* |
1820 | * Do this after blk_queue_make_request() overrides it... | |
1821 | */ | |
1822 | q->nr_requests = set->queue_depth; | |
1823 | ||
24d2f903 CH |
1824 | if (set->ops->complete) |
1825 | blk_queue_softirq_done(q, set->ops->complete); | |
30a91cb4 | 1826 | |
320ae51f | 1827 | blk_mq_init_flush(q); |
24d2f903 | 1828 | blk_mq_init_cpu_queues(q, set->nr_hw_queues); |
320ae51f | 1829 | |
24d2f903 CH |
1830 | q->flush_rq = kzalloc(round_up(sizeof(struct request) + |
1831 | set->cmd_size, cache_line_size()), | |
1832 | GFP_KERNEL); | |
18741986 | 1833 | if (!q->flush_rq) |
320ae51f JA |
1834 | goto err_hw; |
1835 | ||
24d2f903 | 1836 | if (blk_mq_init_hw_queues(q, set)) |
18741986 CH |
1837 | goto err_flush_rq; |
1838 | ||
320ae51f JA |
1839 | mutex_lock(&all_q_mutex); |
1840 | list_add_tail(&q->all_q_node, &all_q_list); | |
1841 | mutex_unlock(&all_q_mutex); | |
1842 | ||
0d2602ca JA |
1843 | blk_mq_add_queue_tag_set(set, q); |
1844 | ||
484b4061 JA |
1845 | blk_mq_map_swqueue(q); |
1846 | ||
320ae51f | 1847 | return q; |
18741986 CH |
1848 | |
1849 | err_flush_rq: | |
1850 | kfree(q->flush_rq); | |
320ae51f | 1851 | err_hw: |
320ae51f JA |
1852 | blk_cleanup_queue(q); |
1853 | err_hctxs: | |
f14bbe77 | 1854 | kfree(map); |
24d2f903 | 1855 | for (i = 0; i < set->nr_hw_queues; i++) { |
320ae51f JA |
1856 | if (!hctxs[i]) |
1857 | break; | |
e4043dcf | 1858 | free_cpumask_var(hctxs[i]->cpumask); |
cdef54dd | 1859 | kfree(hctxs[i]); |
320ae51f | 1860 | } |
f14bbe77 | 1861 | err_map: |
320ae51f JA |
1862 | kfree(hctxs); |
1863 | err_percpu: | |
1864 | free_percpu(ctx); | |
1865 | return ERR_PTR(-ENOMEM); | |
1866 | } | |
1867 | EXPORT_SYMBOL(blk_mq_init_queue); | |
1868 | ||
1869 | void blk_mq_free_queue(struct request_queue *q) | |
1870 | { | |
624dbe47 | 1871 | struct blk_mq_tag_set *set = q->tag_set; |
320ae51f | 1872 | |
0d2602ca JA |
1873 | blk_mq_del_queue_tag_set(q); |
1874 | ||
624dbe47 ML |
1875 | blk_mq_exit_hw_queues(q, set, set->nr_hw_queues); |
1876 | blk_mq_free_hw_queues(q, set); | |
320ae51f | 1877 | |
add703fd | 1878 | percpu_ref_exit(&q->mq_usage_counter); |
3d2936f4 | 1879 | |
320ae51f JA |
1880 | free_percpu(q->queue_ctx); |
1881 | kfree(q->queue_hw_ctx); | |
1882 | kfree(q->mq_map); | |
1883 | ||
1884 | q->queue_ctx = NULL; | |
1885 | q->queue_hw_ctx = NULL; | |
1886 | q->mq_map = NULL; | |
1887 | ||
1888 | mutex_lock(&all_q_mutex); | |
1889 | list_del_init(&q->all_q_node); | |
1890 | mutex_unlock(&all_q_mutex); | |
1891 | } | |
320ae51f JA |
1892 | |
1893 | /* Basically redo blk_mq_init_queue with queue frozen */ | |
f618ef7c | 1894 | static void blk_mq_queue_reinit(struct request_queue *q) |
320ae51f JA |
1895 | { |
1896 | blk_mq_freeze_queue(q); | |
1897 | ||
67aec14c JA |
1898 | blk_mq_sysfs_unregister(q); |
1899 | ||
320ae51f JA |
1900 | blk_mq_update_queue_map(q->mq_map, q->nr_hw_queues); |
1901 | ||
1902 | /* | |
1903 | * redo blk_mq_init_cpu_queues and blk_mq_init_hw_queues. FIXME: maybe | |
1904 | * we should change hctx numa_node according to new topology (this | |
1905 | * involves free and re-allocate memory, worthy doing?) | |
1906 | */ | |
1907 | ||
1908 | blk_mq_map_swqueue(q); | |
1909 | ||
67aec14c JA |
1910 | blk_mq_sysfs_register(q); |
1911 | ||
320ae51f JA |
1912 | blk_mq_unfreeze_queue(q); |
1913 | } | |
1914 | ||
f618ef7c PG |
1915 | static int blk_mq_queue_reinit_notify(struct notifier_block *nb, |
1916 | unsigned long action, void *hcpu) | |
320ae51f JA |
1917 | { |
1918 | struct request_queue *q; | |
1919 | ||
1920 | /* | |
9fccfed8 JA |
1921 | * Before new mappings are established, hotadded cpu might already |
1922 | * start handling requests. This doesn't break anything as we map | |
1923 | * offline CPUs to first hardware queue. We will re-init the queue | |
1924 | * below to get optimal settings. | |
320ae51f JA |
1925 | */ |
1926 | if (action != CPU_DEAD && action != CPU_DEAD_FROZEN && | |
1927 | action != CPU_ONLINE && action != CPU_ONLINE_FROZEN) | |
1928 | return NOTIFY_OK; | |
1929 | ||
1930 | mutex_lock(&all_q_mutex); | |
1931 | list_for_each_entry(q, &all_q_list, all_q_node) | |
1932 | blk_mq_queue_reinit(q); | |
1933 | mutex_unlock(&all_q_mutex); | |
1934 | return NOTIFY_OK; | |
1935 | } | |
1936 | ||
a5164405 JA |
1937 | static int __blk_mq_alloc_rq_maps(struct blk_mq_tag_set *set) |
1938 | { | |
1939 | int i; | |
1940 | ||
1941 | for (i = 0; i < set->nr_hw_queues; i++) { | |
1942 | set->tags[i] = blk_mq_init_rq_map(set, i); | |
1943 | if (!set->tags[i]) | |
1944 | goto out_unwind; | |
1945 | } | |
1946 | ||
1947 | return 0; | |
1948 | ||
1949 | out_unwind: | |
1950 | while (--i >= 0) | |
1951 | blk_mq_free_rq_map(set, set->tags[i], i); | |
1952 | ||
a5164405 JA |
1953 | return -ENOMEM; |
1954 | } | |
1955 | ||
1956 | /* | |
1957 | * Allocate the request maps associated with this tag_set. Note that this | |
1958 | * may reduce the depth asked for, if memory is tight. set->queue_depth | |
1959 | * will be updated to reflect the allocated depth. | |
1960 | */ | |
1961 | static int blk_mq_alloc_rq_maps(struct blk_mq_tag_set *set) | |
1962 | { | |
1963 | unsigned int depth; | |
1964 | int err; | |
1965 | ||
1966 | depth = set->queue_depth; | |
1967 | do { | |
1968 | err = __blk_mq_alloc_rq_maps(set); | |
1969 | if (!err) | |
1970 | break; | |
1971 | ||
1972 | set->queue_depth >>= 1; | |
1973 | if (set->queue_depth < set->reserved_tags + BLK_MQ_TAG_MIN) { | |
1974 | err = -ENOMEM; | |
1975 | break; | |
1976 | } | |
1977 | } while (set->queue_depth); | |
1978 | ||
1979 | if (!set->queue_depth || err) { | |
1980 | pr_err("blk-mq: failed to allocate request map\n"); | |
1981 | return -ENOMEM; | |
1982 | } | |
1983 | ||
1984 | if (depth != set->queue_depth) | |
1985 | pr_info("blk-mq: reduced tag depth (%u -> %u)\n", | |
1986 | depth, set->queue_depth); | |
1987 | ||
1988 | return 0; | |
1989 | } | |
1990 | ||
a4391c64 JA |
1991 | /* |
1992 | * Alloc a tag set to be associated with one or more request queues. | |
1993 | * May fail with EINVAL for various error conditions. May adjust the | |
1994 | * requested depth down, if if it too large. In that case, the set | |
1995 | * value will be stored in set->queue_depth. | |
1996 | */ | |
24d2f903 CH |
1997 | int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set) |
1998 | { | |
24d2f903 CH |
1999 | if (!set->nr_hw_queues) |
2000 | return -EINVAL; | |
a4391c64 | 2001 | if (!set->queue_depth) |
24d2f903 CH |
2002 | return -EINVAL; |
2003 | if (set->queue_depth < set->reserved_tags + BLK_MQ_TAG_MIN) | |
2004 | return -EINVAL; | |
2005 | ||
cdef54dd | 2006 | if (!set->nr_hw_queues || !set->ops->queue_rq || !set->ops->map_queue) |
24d2f903 CH |
2007 | return -EINVAL; |
2008 | ||
a4391c64 JA |
2009 | if (set->queue_depth > BLK_MQ_MAX_DEPTH) { |
2010 | pr_info("blk-mq: reduced tag depth to %u\n", | |
2011 | BLK_MQ_MAX_DEPTH); | |
2012 | set->queue_depth = BLK_MQ_MAX_DEPTH; | |
2013 | } | |
24d2f903 | 2014 | |
48479005 ML |
2015 | set->tags = kmalloc_node(set->nr_hw_queues * |
2016 | sizeof(struct blk_mq_tags *), | |
24d2f903 CH |
2017 | GFP_KERNEL, set->numa_node); |
2018 | if (!set->tags) | |
a5164405 | 2019 | return -ENOMEM; |
24d2f903 | 2020 | |
a5164405 JA |
2021 | if (blk_mq_alloc_rq_maps(set)) |
2022 | goto enomem; | |
24d2f903 | 2023 | |
0d2602ca JA |
2024 | mutex_init(&set->tag_list_lock); |
2025 | INIT_LIST_HEAD(&set->tag_list); | |
2026 | ||
24d2f903 | 2027 | return 0; |
a5164405 | 2028 | enomem: |
5676e7b6 RE |
2029 | kfree(set->tags); |
2030 | set->tags = NULL; | |
24d2f903 CH |
2031 | return -ENOMEM; |
2032 | } | |
2033 | EXPORT_SYMBOL(blk_mq_alloc_tag_set); | |
2034 | ||
2035 | void blk_mq_free_tag_set(struct blk_mq_tag_set *set) | |
2036 | { | |
2037 | int i; | |
2038 | ||
484b4061 JA |
2039 | for (i = 0; i < set->nr_hw_queues; i++) { |
2040 | if (set->tags[i]) | |
2041 | blk_mq_free_rq_map(set, set->tags[i], i); | |
2042 | } | |
2043 | ||
981bd189 | 2044 | kfree(set->tags); |
5676e7b6 | 2045 | set->tags = NULL; |
24d2f903 CH |
2046 | } |
2047 | EXPORT_SYMBOL(blk_mq_free_tag_set); | |
2048 | ||
e3a2b3f9 JA |
2049 | int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr) |
2050 | { | |
2051 | struct blk_mq_tag_set *set = q->tag_set; | |
2052 | struct blk_mq_hw_ctx *hctx; | |
2053 | int i, ret; | |
2054 | ||
2055 | if (!set || nr > set->queue_depth) | |
2056 | return -EINVAL; | |
2057 | ||
2058 | ret = 0; | |
2059 | queue_for_each_hw_ctx(q, hctx, i) { | |
2060 | ret = blk_mq_tag_update_depth(hctx->tags, nr); | |
2061 | if (ret) | |
2062 | break; | |
2063 | } | |
2064 | ||
2065 | if (!ret) | |
2066 | q->nr_requests = nr; | |
2067 | ||
2068 | return ret; | |
2069 | } | |
2070 | ||
676141e4 JA |
2071 | void blk_mq_disable_hotplug(void) |
2072 | { | |
2073 | mutex_lock(&all_q_mutex); | |
2074 | } | |
2075 | ||
2076 | void blk_mq_enable_hotplug(void) | |
2077 | { | |
2078 | mutex_unlock(&all_q_mutex); | |
2079 | } | |
2080 | ||
320ae51f JA |
2081 | static int __init blk_mq_init(void) |
2082 | { | |
320ae51f JA |
2083 | blk_mq_cpu_init(); |
2084 | ||
add703fd | 2085 | hotcpu_notifier(blk_mq_queue_reinit_notify, 0); |
320ae51f JA |
2086 | |
2087 | return 0; | |
2088 | } | |
2089 | subsys_initcall(blk_mq_init); |