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