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 | { | |
81 | int ret; | |
82 | ||
83 | __percpu_counter_add(&q->mq_usage_counter, 1, 1000000); | |
84 | smp_wmb(); | |
3b632cf0 KB |
85 | |
86 | /* we have problems freezing the queue if it's initializing */ | |
87 | if (!blk_queue_dying(q) && | |
88 | (!blk_queue_bypass(q) || !blk_queue_init_done(q))) | |
320ae51f JA |
89 | return 0; |
90 | ||
91 | __percpu_counter_add(&q->mq_usage_counter, -1, 1000000); | |
92 | ||
93 | spin_lock_irq(q->queue_lock); | |
94 | ret = wait_event_interruptible_lock_irq(q->mq_freeze_wq, | |
43a5e4e2 ML |
95 | !blk_queue_bypass(q) || blk_queue_dying(q), |
96 | *q->queue_lock); | |
320ae51f | 97 | /* inc usage with lock hold to avoid freeze_queue runs here */ |
43a5e4e2 | 98 | if (!ret && !blk_queue_dying(q)) |
320ae51f | 99 | __percpu_counter_add(&q->mq_usage_counter, 1, 1000000); |
43a5e4e2 ML |
100 | else if (blk_queue_dying(q)) |
101 | ret = -ENODEV; | |
320ae51f JA |
102 | spin_unlock_irq(q->queue_lock); |
103 | ||
104 | return ret; | |
105 | } | |
106 | ||
107 | static void blk_mq_queue_exit(struct request_queue *q) | |
108 | { | |
109 | __percpu_counter_add(&q->mq_usage_counter, -1, 1000000); | |
110 | } | |
111 | ||
95ed0681 | 112 | void blk_mq_drain_queue(struct request_queue *q) |
43a5e4e2 ML |
113 | { |
114 | while (true) { | |
115 | s64 count; | |
116 | ||
117 | spin_lock_irq(q->queue_lock); | |
118 | count = percpu_counter_sum(&q->mq_usage_counter); | |
119 | spin_unlock_irq(q->queue_lock); | |
120 | ||
121 | if (count == 0) | |
122 | break; | |
8f5280f4 | 123 | blk_mq_start_hw_queues(q); |
43a5e4e2 ML |
124 | msleep(10); |
125 | } | |
126 | } | |
127 | ||
320ae51f JA |
128 | /* |
129 | * Guarantee no request is in use, so we can change any data structure of | |
130 | * the queue afterward. | |
131 | */ | |
132 | static void blk_mq_freeze_queue(struct request_queue *q) | |
133 | { | |
134 | bool drain; | |
135 | ||
136 | spin_lock_irq(q->queue_lock); | |
137 | drain = !q->bypass_depth++; | |
138 | queue_flag_set(QUEUE_FLAG_BYPASS, q); | |
139 | spin_unlock_irq(q->queue_lock); | |
140 | ||
43a5e4e2 | 141 | if (drain) |
95ed0681 | 142 | blk_mq_drain_queue(q); |
320ae51f JA |
143 | } |
144 | ||
145 | static void blk_mq_unfreeze_queue(struct request_queue *q) | |
146 | { | |
147 | bool wake = false; | |
148 | ||
149 | spin_lock_irq(q->queue_lock); | |
150 | if (!--q->bypass_depth) { | |
151 | queue_flag_clear(QUEUE_FLAG_BYPASS, q); | |
152 | wake = true; | |
153 | } | |
154 | WARN_ON_ONCE(q->bypass_depth < 0); | |
155 | spin_unlock_irq(q->queue_lock); | |
156 | if (wake) | |
157 | wake_up_all(&q->mq_freeze_wq); | |
158 | } | |
159 | ||
160 | bool blk_mq_can_queue(struct blk_mq_hw_ctx *hctx) | |
161 | { | |
162 | return blk_mq_has_free_tags(hctx->tags); | |
163 | } | |
164 | EXPORT_SYMBOL(blk_mq_can_queue); | |
165 | ||
94eddfbe JA |
166 | static void blk_mq_rq_ctx_init(struct request_queue *q, struct blk_mq_ctx *ctx, |
167 | struct request *rq, unsigned int rw_flags) | |
320ae51f | 168 | { |
94eddfbe JA |
169 | if (blk_queue_io_stat(q)) |
170 | rw_flags |= REQ_IO_STAT; | |
171 | ||
af76e555 CH |
172 | INIT_LIST_HEAD(&rq->queuelist); |
173 | /* csd/requeue_work/fifo_time is initialized before use */ | |
174 | rq->q = q; | |
320ae51f | 175 | rq->mq_ctx = ctx; |
0d2602ca | 176 | rq->cmd_flags |= rw_flags; |
af76e555 CH |
177 | /* do not touch atomic flags, it needs atomic ops against the timer */ |
178 | rq->cpu = -1; | |
af76e555 CH |
179 | INIT_HLIST_NODE(&rq->hash); |
180 | RB_CLEAR_NODE(&rq->rb_node); | |
af76e555 CH |
181 | rq->rq_disk = NULL; |
182 | rq->part = NULL; | |
3ee32372 | 183 | rq->start_time = jiffies; |
af76e555 CH |
184 | #ifdef CONFIG_BLK_CGROUP |
185 | rq->rl = NULL; | |
0fec08b4 | 186 | set_start_time_ns(rq); |
af76e555 CH |
187 | rq->io_start_time_ns = 0; |
188 | #endif | |
189 | rq->nr_phys_segments = 0; | |
190 | #if defined(CONFIG_BLK_DEV_INTEGRITY) | |
191 | rq->nr_integrity_segments = 0; | |
192 | #endif | |
af76e555 CH |
193 | rq->special = NULL; |
194 | /* tag was already set */ | |
195 | rq->errors = 0; | |
af76e555 CH |
196 | |
197 | rq->extra_len = 0; | |
198 | rq->sense_len = 0; | |
199 | rq->resid_len = 0; | |
200 | rq->sense = NULL; | |
201 | ||
af76e555 | 202 | INIT_LIST_HEAD(&rq->timeout_list); |
f6be4fb4 JA |
203 | rq->timeout = 0; |
204 | ||
af76e555 CH |
205 | rq->end_io = NULL; |
206 | rq->end_io_data = NULL; | |
207 | rq->next_rq = NULL; | |
208 | ||
320ae51f JA |
209 | ctx->rq_dispatched[rw_is_sync(rw_flags)]++; |
210 | } | |
211 | ||
5dee8577 | 212 | static struct request * |
cb96a42c | 213 | __blk_mq_alloc_request(struct blk_mq_alloc_data *data, int rw) |
5dee8577 CH |
214 | { |
215 | struct request *rq; | |
216 | unsigned int tag; | |
217 | ||
cb96a42c | 218 | tag = blk_mq_get_tag(data); |
5dee8577 | 219 | if (tag != BLK_MQ_TAG_FAIL) { |
cb96a42c | 220 | rq = data->hctx->tags->rqs[tag]; |
5dee8577 CH |
221 | |
222 | rq->cmd_flags = 0; | |
cb96a42c | 223 | if (blk_mq_tag_busy(data->hctx)) { |
5dee8577 | 224 | rq->cmd_flags = REQ_MQ_INFLIGHT; |
cb96a42c | 225 | atomic_inc(&data->hctx->nr_active); |
5dee8577 CH |
226 | } |
227 | ||
228 | rq->tag = tag; | |
cb96a42c | 229 | blk_mq_rq_ctx_init(data->q, data->ctx, rq, rw); |
5dee8577 CH |
230 | return rq; |
231 | } | |
232 | ||
233 | return NULL; | |
234 | } | |
235 | ||
4ce01dd1 CH |
236 | struct request *blk_mq_alloc_request(struct request_queue *q, int rw, gfp_t gfp, |
237 | bool reserved) | |
320ae51f | 238 | { |
d852564f CH |
239 | struct blk_mq_ctx *ctx; |
240 | struct blk_mq_hw_ctx *hctx; | |
320ae51f | 241 | struct request *rq; |
cb96a42c | 242 | struct blk_mq_alloc_data alloc_data; |
320ae51f JA |
243 | |
244 | if (blk_mq_queue_enter(q)) | |
245 | return NULL; | |
246 | ||
d852564f CH |
247 | ctx = blk_mq_get_ctx(q); |
248 | hctx = q->mq_ops->map_queue(q, ctx->cpu); | |
cb96a42c ML |
249 | blk_mq_set_alloc_data(&alloc_data, q, gfp & ~__GFP_WAIT, |
250 | reserved, ctx, hctx); | |
d852564f | 251 | |
cb96a42c | 252 | rq = __blk_mq_alloc_request(&alloc_data, rw); |
d852564f CH |
253 | if (!rq && (gfp & __GFP_WAIT)) { |
254 | __blk_mq_run_hw_queue(hctx); | |
255 | blk_mq_put_ctx(ctx); | |
256 | ||
257 | ctx = blk_mq_get_ctx(q); | |
258 | hctx = q->mq_ops->map_queue(q, ctx->cpu); | |
cb96a42c ML |
259 | blk_mq_set_alloc_data(&alloc_data, q, gfp, reserved, ctx, |
260 | hctx); | |
261 | rq = __blk_mq_alloc_request(&alloc_data, rw); | |
262 | ctx = alloc_data.ctx; | |
d852564f CH |
263 | } |
264 | blk_mq_put_ctx(ctx); | |
320ae51f JA |
265 | return rq; |
266 | } | |
4bb659b1 | 267 | EXPORT_SYMBOL(blk_mq_alloc_request); |
320ae51f | 268 | |
320ae51f JA |
269 | static void __blk_mq_free_request(struct blk_mq_hw_ctx *hctx, |
270 | struct blk_mq_ctx *ctx, struct request *rq) | |
271 | { | |
272 | const int tag = rq->tag; | |
273 | struct request_queue *q = rq->q; | |
274 | ||
0d2602ca JA |
275 | if (rq->cmd_flags & REQ_MQ_INFLIGHT) |
276 | atomic_dec(&hctx->nr_active); | |
277 | ||
af76e555 | 278 | clear_bit(REQ_ATOM_STARTED, &rq->atomic_flags); |
0d2602ca | 279 | blk_mq_put_tag(hctx, tag, &ctx->last_tag); |
320ae51f JA |
280 | blk_mq_queue_exit(q); |
281 | } | |
282 | ||
283 | void blk_mq_free_request(struct request *rq) | |
284 | { | |
285 | struct blk_mq_ctx *ctx = rq->mq_ctx; | |
286 | struct blk_mq_hw_ctx *hctx; | |
287 | struct request_queue *q = rq->q; | |
288 | ||
289 | ctx->rq_completed[rq_is_sync(rq)]++; | |
290 | ||
291 | hctx = q->mq_ops->map_queue(q, ctx->cpu); | |
292 | __blk_mq_free_request(hctx, ctx, rq); | |
293 | } | |
294 | ||
8727af4b CH |
295 | /* |
296 | * Clone all relevant state from a request that has been put on hold in | |
297 | * the flush state machine into the preallocated flush request that hangs | |
298 | * off the request queue. | |
299 | * | |
300 | * For a driver the flush request should be invisible, that's why we are | |
301 | * impersonating the original request here. | |
302 | */ | |
303 | void blk_mq_clone_flush_request(struct request *flush_rq, | |
304 | struct request *orig_rq) | |
305 | { | |
306 | struct blk_mq_hw_ctx *hctx = | |
307 | orig_rq->q->mq_ops->map_queue(orig_rq->q, orig_rq->mq_ctx->cpu); | |
308 | ||
309 | flush_rq->mq_ctx = orig_rq->mq_ctx; | |
310 | flush_rq->tag = orig_rq->tag; | |
311 | memcpy(blk_mq_rq_to_pdu(flush_rq), blk_mq_rq_to_pdu(orig_rq), | |
312 | hctx->cmd_size); | |
313 | } | |
314 | ||
63151a44 | 315 | inline void __blk_mq_end_io(struct request *rq, int error) |
320ae51f | 316 | { |
0d11e6ac ML |
317 | blk_account_io_done(rq); |
318 | ||
91b63639 | 319 | if (rq->end_io) { |
320ae51f | 320 | rq->end_io(rq, error); |
91b63639 CH |
321 | } else { |
322 | if (unlikely(blk_bidi_rq(rq))) | |
323 | blk_mq_free_request(rq->next_rq); | |
320ae51f | 324 | blk_mq_free_request(rq); |
91b63639 | 325 | } |
320ae51f | 326 | } |
63151a44 CH |
327 | EXPORT_SYMBOL(__blk_mq_end_io); |
328 | ||
329 | void blk_mq_end_io(struct request *rq, int error) | |
330 | { | |
331 | if (blk_update_request(rq, error, blk_rq_bytes(rq))) | |
332 | BUG(); | |
333 | __blk_mq_end_io(rq, error); | |
334 | } | |
335 | EXPORT_SYMBOL(blk_mq_end_io); | |
320ae51f | 336 | |
30a91cb4 | 337 | static void __blk_mq_complete_request_remote(void *data) |
320ae51f | 338 | { |
3d6efbf6 | 339 | struct request *rq = data; |
320ae51f | 340 | |
30a91cb4 | 341 | rq->q->softirq_done_fn(rq); |
320ae51f | 342 | } |
320ae51f | 343 | |
ed851860 | 344 | static void blk_mq_ipi_complete_request(struct request *rq) |
320ae51f JA |
345 | { |
346 | struct blk_mq_ctx *ctx = rq->mq_ctx; | |
38535201 | 347 | bool shared = false; |
320ae51f JA |
348 | int cpu; |
349 | ||
38535201 | 350 | if (!test_bit(QUEUE_FLAG_SAME_COMP, &rq->q->queue_flags)) { |
30a91cb4 CH |
351 | rq->q->softirq_done_fn(rq); |
352 | return; | |
353 | } | |
320ae51f JA |
354 | |
355 | cpu = get_cpu(); | |
38535201 CH |
356 | if (!test_bit(QUEUE_FLAG_SAME_FORCE, &rq->q->queue_flags)) |
357 | shared = cpus_share_cache(cpu, ctx->cpu); | |
358 | ||
359 | if (cpu != ctx->cpu && !shared && cpu_online(ctx->cpu)) { | |
30a91cb4 | 360 | rq->csd.func = __blk_mq_complete_request_remote; |
3d6efbf6 CH |
361 | rq->csd.info = rq; |
362 | rq->csd.flags = 0; | |
c46fff2a | 363 | smp_call_function_single_async(ctx->cpu, &rq->csd); |
3d6efbf6 | 364 | } else { |
30a91cb4 | 365 | rq->q->softirq_done_fn(rq); |
3d6efbf6 | 366 | } |
320ae51f JA |
367 | put_cpu(); |
368 | } | |
30a91cb4 | 369 | |
ed851860 JA |
370 | void __blk_mq_complete_request(struct request *rq) |
371 | { | |
372 | struct request_queue *q = rq->q; | |
373 | ||
374 | if (!q->softirq_done_fn) | |
375 | blk_mq_end_io(rq, rq->errors); | |
376 | else | |
377 | blk_mq_ipi_complete_request(rq); | |
378 | } | |
379 | ||
30a91cb4 CH |
380 | /** |
381 | * blk_mq_complete_request - end I/O on a request | |
382 | * @rq: the request being processed | |
383 | * | |
384 | * Description: | |
385 | * Ends all I/O on a request. It does not handle partial completions. | |
386 | * The actual completion happens out-of-order, through a IPI handler. | |
387 | **/ | |
388 | void blk_mq_complete_request(struct request *rq) | |
389 | { | |
95f09684 JA |
390 | struct request_queue *q = rq->q; |
391 | ||
392 | if (unlikely(blk_should_fake_timeout(q))) | |
30a91cb4 | 393 | return; |
ed851860 JA |
394 | if (!blk_mark_rq_complete(rq)) |
395 | __blk_mq_complete_request(rq); | |
30a91cb4 CH |
396 | } |
397 | EXPORT_SYMBOL(blk_mq_complete_request); | |
320ae51f | 398 | |
49f5baa5 | 399 | static void blk_mq_start_request(struct request *rq, bool last) |
320ae51f JA |
400 | { |
401 | struct request_queue *q = rq->q; | |
402 | ||
403 | trace_block_rq_issue(q, rq); | |
404 | ||
742ee69b | 405 | rq->resid_len = blk_rq_bytes(rq); |
91b63639 CH |
406 | if (unlikely(blk_bidi_rq(rq))) |
407 | rq->next_rq->resid_len = blk_rq_bytes(rq->next_rq); | |
742ee69b | 408 | |
2b8393b4 | 409 | blk_add_timer(rq); |
87ee7b11 JA |
410 | |
411 | /* | |
412 | * Mark us as started and clear complete. Complete might have been | |
413 | * set if requeue raced with timeout, which then marked it as | |
414 | * complete. So be sure to clear complete again when we start | |
415 | * the request, otherwise we'll ignore the completion event. | |
416 | */ | |
4b570521 JA |
417 | if (!test_bit(REQ_ATOM_STARTED, &rq->atomic_flags)) |
418 | set_bit(REQ_ATOM_STARTED, &rq->atomic_flags); | |
419 | if (test_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags)) | |
420 | clear_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags); | |
49f5baa5 CH |
421 | |
422 | if (q->dma_drain_size && blk_rq_bytes(rq)) { | |
423 | /* | |
424 | * Make sure space for the drain appears. We know we can do | |
425 | * this because max_hw_segments has been adjusted to be one | |
426 | * fewer than the device can handle. | |
427 | */ | |
428 | rq->nr_phys_segments++; | |
429 | } | |
430 | ||
431 | /* | |
432 | * Flag the last request in the series so that drivers know when IO | |
433 | * should be kicked off, if they don't do it on a per-request basis. | |
434 | * | |
435 | * Note: the flag isn't the only condition drivers should do kick off. | |
436 | * If drive is busy, the last request might not have the bit set. | |
437 | */ | |
438 | if (last) | |
439 | rq->cmd_flags |= REQ_END; | |
320ae51f JA |
440 | } |
441 | ||
ed0791b2 | 442 | static void __blk_mq_requeue_request(struct request *rq) |
320ae51f JA |
443 | { |
444 | struct request_queue *q = rq->q; | |
445 | ||
446 | trace_block_rq_requeue(q, rq); | |
447 | clear_bit(REQ_ATOM_STARTED, &rq->atomic_flags); | |
49f5baa5 CH |
448 | |
449 | rq->cmd_flags &= ~REQ_END; | |
450 | ||
451 | if (q->dma_drain_size && blk_rq_bytes(rq)) | |
452 | rq->nr_phys_segments--; | |
320ae51f JA |
453 | } |
454 | ||
ed0791b2 CH |
455 | void blk_mq_requeue_request(struct request *rq) |
456 | { | |
ed0791b2 CH |
457 | __blk_mq_requeue_request(rq); |
458 | blk_clear_rq_complete(rq); | |
459 | ||
ed0791b2 | 460 | BUG_ON(blk_queued_rq(rq)); |
6fca6a61 | 461 | blk_mq_add_to_requeue_list(rq, true); |
ed0791b2 CH |
462 | } |
463 | EXPORT_SYMBOL(blk_mq_requeue_request); | |
464 | ||
6fca6a61 CH |
465 | static void blk_mq_requeue_work(struct work_struct *work) |
466 | { | |
467 | struct request_queue *q = | |
468 | container_of(work, struct request_queue, requeue_work); | |
469 | LIST_HEAD(rq_list); | |
470 | struct request *rq, *next; | |
471 | unsigned long flags; | |
472 | ||
473 | spin_lock_irqsave(&q->requeue_lock, flags); | |
474 | list_splice_init(&q->requeue_list, &rq_list); | |
475 | spin_unlock_irqrestore(&q->requeue_lock, flags); | |
476 | ||
477 | list_for_each_entry_safe(rq, next, &rq_list, queuelist) { | |
478 | if (!(rq->cmd_flags & REQ_SOFTBARRIER)) | |
479 | continue; | |
480 | ||
481 | rq->cmd_flags &= ~REQ_SOFTBARRIER; | |
482 | list_del_init(&rq->queuelist); | |
483 | blk_mq_insert_request(rq, true, false, false); | |
484 | } | |
485 | ||
486 | while (!list_empty(&rq_list)) { | |
487 | rq = list_entry(rq_list.next, struct request, queuelist); | |
488 | list_del_init(&rq->queuelist); | |
489 | blk_mq_insert_request(rq, false, false, false); | |
490 | } | |
491 | ||
492 | blk_mq_run_queues(q, false); | |
493 | } | |
494 | ||
495 | void blk_mq_add_to_requeue_list(struct request *rq, bool at_head) | |
496 | { | |
497 | struct request_queue *q = rq->q; | |
498 | unsigned long flags; | |
499 | ||
500 | /* | |
501 | * We abuse this flag that is otherwise used by the I/O scheduler to | |
502 | * request head insertation from the workqueue. | |
503 | */ | |
504 | BUG_ON(rq->cmd_flags & REQ_SOFTBARRIER); | |
505 | ||
506 | spin_lock_irqsave(&q->requeue_lock, flags); | |
507 | if (at_head) { | |
508 | rq->cmd_flags |= REQ_SOFTBARRIER; | |
509 | list_add(&rq->queuelist, &q->requeue_list); | |
510 | } else { | |
511 | list_add_tail(&rq->queuelist, &q->requeue_list); | |
512 | } | |
513 | spin_unlock_irqrestore(&q->requeue_lock, flags); | |
514 | } | |
515 | EXPORT_SYMBOL(blk_mq_add_to_requeue_list); | |
516 | ||
517 | void blk_mq_kick_requeue_list(struct request_queue *q) | |
518 | { | |
519 | kblockd_schedule_work(&q->requeue_work); | |
520 | } | |
521 | EXPORT_SYMBOL(blk_mq_kick_requeue_list); | |
522 | ||
0e62f51f | 523 | static inline bool is_flush_request(struct request *rq, unsigned int tag) |
24d2f903 | 524 | { |
0e62f51f JA |
525 | return ((rq->cmd_flags & REQ_FLUSH_SEQ) && |
526 | rq->q->flush_rq->tag == tag); | |
527 | } | |
528 | ||
529 | struct request *blk_mq_tag_to_rq(struct blk_mq_tags *tags, unsigned int tag) | |
530 | { | |
531 | struct request *rq = tags->rqs[tag]; | |
22302375 | 532 | |
0e62f51f JA |
533 | if (!is_flush_request(rq, tag)) |
534 | return rq; | |
22302375 | 535 | |
0e62f51f | 536 | return rq->q->flush_rq; |
24d2f903 CH |
537 | } |
538 | EXPORT_SYMBOL(blk_mq_tag_to_rq); | |
539 | ||
320ae51f JA |
540 | struct blk_mq_timeout_data { |
541 | struct blk_mq_hw_ctx *hctx; | |
542 | unsigned long *next; | |
543 | unsigned int *next_set; | |
544 | }; | |
545 | ||
546 | static void blk_mq_timeout_check(void *__data, unsigned long *free_tags) | |
547 | { | |
548 | struct blk_mq_timeout_data *data = __data; | |
549 | struct blk_mq_hw_ctx *hctx = data->hctx; | |
550 | unsigned int tag; | |
551 | ||
552 | /* It may not be in flight yet (this is where | |
553 | * the REQ_ATOMIC_STARTED flag comes in). The requests are | |
554 | * statically allocated, so we know it's always safe to access the | |
555 | * memory associated with a bit offset into ->rqs[]. | |
556 | */ | |
557 | tag = 0; | |
558 | do { | |
559 | struct request *rq; | |
560 | ||
24d2f903 CH |
561 | tag = find_next_zero_bit(free_tags, hctx->tags->nr_tags, tag); |
562 | if (tag >= hctx->tags->nr_tags) | |
320ae51f JA |
563 | break; |
564 | ||
0e62f51f | 565 | rq = blk_mq_tag_to_rq(hctx->tags, tag++); |
24d2f903 CH |
566 | if (rq->q != hctx->queue) |
567 | continue; | |
320ae51f JA |
568 | if (!test_bit(REQ_ATOM_STARTED, &rq->atomic_flags)) |
569 | continue; | |
570 | ||
571 | blk_rq_check_expired(rq, data->next, data->next_set); | |
572 | } while (1); | |
573 | } | |
574 | ||
575 | static void blk_mq_hw_ctx_check_timeout(struct blk_mq_hw_ctx *hctx, | |
576 | unsigned long *next, | |
577 | unsigned int *next_set) | |
578 | { | |
579 | struct blk_mq_timeout_data data = { | |
580 | .hctx = hctx, | |
581 | .next = next, | |
582 | .next_set = next_set, | |
583 | }; | |
584 | ||
585 | /* | |
586 | * Ask the tagging code to iterate busy requests, so we can | |
587 | * check them for timeout. | |
588 | */ | |
589 | blk_mq_tag_busy_iter(hctx->tags, blk_mq_timeout_check, &data); | |
590 | } | |
591 | ||
87ee7b11 JA |
592 | static enum blk_eh_timer_return blk_mq_rq_timed_out(struct request *rq) |
593 | { | |
594 | struct request_queue *q = rq->q; | |
595 | ||
596 | /* | |
597 | * We know that complete is set at this point. If STARTED isn't set | |
598 | * anymore, then the request isn't active and the "timeout" should | |
599 | * just be ignored. This can happen due to the bitflag ordering. | |
600 | * Timeout first checks if STARTED is set, and if it is, assumes | |
601 | * the request is active. But if we race with completion, then | |
602 | * we both flags will get cleared. So check here again, and ignore | |
603 | * a timeout event with a request that isn't active. | |
604 | */ | |
605 | if (!test_bit(REQ_ATOM_STARTED, &rq->atomic_flags)) | |
606 | return BLK_EH_NOT_HANDLED; | |
607 | ||
608 | if (!q->mq_ops->timeout) | |
609 | return BLK_EH_RESET_TIMER; | |
610 | ||
611 | return q->mq_ops->timeout(rq); | |
612 | } | |
613 | ||
320ae51f JA |
614 | static void blk_mq_rq_timer(unsigned long data) |
615 | { | |
616 | struct request_queue *q = (struct request_queue *) data; | |
617 | struct blk_mq_hw_ctx *hctx; | |
618 | unsigned long next = 0; | |
619 | int i, next_set = 0; | |
620 | ||
484b4061 JA |
621 | queue_for_each_hw_ctx(q, hctx, i) { |
622 | /* | |
623 | * If not software queues are currently mapped to this | |
624 | * hardware queue, there's nothing to check | |
625 | */ | |
626 | if (!hctx->nr_ctx || !hctx->tags) | |
627 | continue; | |
628 | ||
320ae51f | 629 | blk_mq_hw_ctx_check_timeout(hctx, &next, &next_set); |
484b4061 | 630 | } |
320ae51f | 631 | |
0d2602ca JA |
632 | if (next_set) { |
633 | next = blk_rq_timeout(round_jiffies_up(next)); | |
634 | mod_timer(&q->timeout, next); | |
635 | } else { | |
636 | queue_for_each_hw_ctx(q, hctx, i) | |
637 | blk_mq_tag_idle(hctx); | |
638 | } | |
320ae51f JA |
639 | } |
640 | ||
641 | /* | |
642 | * Reverse check our software queue for entries that we could potentially | |
643 | * merge with. Currently includes a hand-wavy stop count of 8, to not spend | |
644 | * too much time checking for merges. | |
645 | */ | |
646 | static bool blk_mq_attempt_merge(struct request_queue *q, | |
647 | struct blk_mq_ctx *ctx, struct bio *bio) | |
648 | { | |
649 | struct request *rq; | |
650 | int checked = 8; | |
651 | ||
652 | list_for_each_entry_reverse(rq, &ctx->rq_list, queuelist) { | |
653 | int el_ret; | |
654 | ||
655 | if (!checked--) | |
656 | break; | |
657 | ||
658 | if (!blk_rq_merge_ok(rq, bio)) | |
659 | continue; | |
660 | ||
661 | el_ret = blk_try_merge(rq, bio); | |
662 | if (el_ret == ELEVATOR_BACK_MERGE) { | |
663 | if (bio_attempt_back_merge(q, rq, bio)) { | |
664 | ctx->rq_merged++; | |
665 | return true; | |
666 | } | |
667 | break; | |
668 | } else if (el_ret == ELEVATOR_FRONT_MERGE) { | |
669 | if (bio_attempt_front_merge(q, rq, bio)) { | |
670 | ctx->rq_merged++; | |
671 | return true; | |
672 | } | |
673 | break; | |
674 | } | |
675 | } | |
676 | ||
677 | return false; | |
678 | } | |
679 | ||
1429d7c9 JA |
680 | /* |
681 | * Process software queues that have been marked busy, splicing them | |
682 | * to the for-dispatch | |
683 | */ | |
684 | static void flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, struct list_head *list) | |
685 | { | |
686 | struct blk_mq_ctx *ctx; | |
687 | int i; | |
688 | ||
689 | for (i = 0; i < hctx->ctx_map.map_size; i++) { | |
690 | struct blk_align_bitmap *bm = &hctx->ctx_map.map[i]; | |
691 | unsigned int off, bit; | |
692 | ||
693 | if (!bm->word) | |
694 | continue; | |
695 | ||
696 | bit = 0; | |
697 | off = i * hctx->ctx_map.bits_per_word; | |
698 | do { | |
699 | bit = find_next_bit(&bm->word, bm->depth, bit); | |
700 | if (bit >= bm->depth) | |
701 | break; | |
702 | ||
703 | ctx = hctx->ctxs[bit + off]; | |
704 | clear_bit(bit, &bm->word); | |
705 | spin_lock(&ctx->lock); | |
706 | list_splice_tail_init(&ctx->rq_list, list); | |
707 | spin_unlock(&ctx->lock); | |
708 | ||
709 | bit++; | |
710 | } while (1); | |
711 | } | |
712 | } | |
713 | ||
320ae51f JA |
714 | /* |
715 | * Run this hardware queue, pulling any software queues mapped to it in. | |
716 | * Note that this function currently has various problems around ordering | |
717 | * of IO. In particular, we'd like FIFO behaviour on handling existing | |
718 | * items on the hctx->dispatch list. Ignore that for now. | |
719 | */ | |
720 | static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx) | |
721 | { | |
722 | struct request_queue *q = hctx->queue; | |
320ae51f JA |
723 | struct request *rq; |
724 | LIST_HEAD(rq_list); | |
1429d7c9 | 725 | int queued; |
320ae51f | 726 | |
fd1270d5 | 727 | WARN_ON(!cpumask_test_cpu(raw_smp_processor_id(), hctx->cpumask)); |
e4043dcf | 728 | |
5d12f905 | 729 | if (unlikely(test_bit(BLK_MQ_S_STOPPED, &hctx->state))) |
320ae51f JA |
730 | return; |
731 | ||
732 | hctx->run++; | |
733 | ||
734 | /* | |
735 | * Touch any software queue that has pending entries. | |
736 | */ | |
1429d7c9 | 737 | flush_busy_ctxs(hctx, &rq_list); |
320ae51f JA |
738 | |
739 | /* | |
740 | * If we have previous entries on our dispatch list, grab them | |
741 | * and stuff them at the front for more fair dispatch. | |
742 | */ | |
743 | if (!list_empty_careful(&hctx->dispatch)) { | |
744 | spin_lock(&hctx->lock); | |
745 | if (!list_empty(&hctx->dispatch)) | |
746 | list_splice_init(&hctx->dispatch, &rq_list); | |
747 | spin_unlock(&hctx->lock); | |
748 | } | |
749 | ||
320ae51f JA |
750 | /* |
751 | * Now process all the entries, sending them to the driver. | |
752 | */ | |
1429d7c9 | 753 | queued = 0; |
320ae51f JA |
754 | while (!list_empty(&rq_list)) { |
755 | int ret; | |
756 | ||
757 | rq = list_first_entry(&rq_list, struct request, queuelist); | |
758 | list_del_init(&rq->queuelist); | |
320ae51f | 759 | |
49f5baa5 | 760 | blk_mq_start_request(rq, list_empty(&rq_list)); |
320ae51f JA |
761 | |
762 | ret = q->mq_ops->queue_rq(hctx, rq); | |
763 | switch (ret) { | |
764 | case BLK_MQ_RQ_QUEUE_OK: | |
765 | queued++; | |
766 | continue; | |
767 | case BLK_MQ_RQ_QUEUE_BUSY: | |
320ae51f | 768 | list_add(&rq->queuelist, &rq_list); |
ed0791b2 | 769 | __blk_mq_requeue_request(rq); |
320ae51f JA |
770 | break; |
771 | default: | |
772 | pr_err("blk-mq: bad return on queue: %d\n", ret); | |
320ae51f | 773 | case BLK_MQ_RQ_QUEUE_ERROR: |
1e93b8c2 | 774 | rq->errors = -EIO; |
320ae51f JA |
775 | blk_mq_end_io(rq, rq->errors); |
776 | break; | |
777 | } | |
778 | ||
779 | if (ret == BLK_MQ_RQ_QUEUE_BUSY) | |
780 | break; | |
781 | } | |
782 | ||
783 | if (!queued) | |
784 | hctx->dispatched[0]++; | |
785 | else if (queued < (1 << (BLK_MQ_MAX_DISPATCH_ORDER - 1))) | |
786 | hctx->dispatched[ilog2(queued) + 1]++; | |
787 | ||
788 | /* | |
789 | * Any items that need requeuing? Stuff them into hctx->dispatch, | |
790 | * that is where we will continue on next queue run. | |
791 | */ | |
792 | if (!list_empty(&rq_list)) { | |
793 | spin_lock(&hctx->lock); | |
794 | list_splice(&rq_list, &hctx->dispatch); | |
795 | spin_unlock(&hctx->lock); | |
796 | } | |
797 | } | |
798 | ||
506e931f JA |
799 | /* |
800 | * It'd be great if the workqueue API had a way to pass | |
801 | * in a mask and had some smarts for more clever placement. | |
802 | * For now we just round-robin here, switching for every | |
803 | * BLK_MQ_CPU_WORK_BATCH queued items. | |
804 | */ | |
805 | static int blk_mq_hctx_next_cpu(struct blk_mq_hw_ctx *hctx) | |
806 | { | |
807 | int cpu = hctx->next_cpu; | |
808 | ||
809 | if (--hctx->next_cpu_batch <= 0) { | |
810 | int next_cpu; | |
811 | ||
812 | next_cpu = cpumask_next(hctx->next_cpu, hctx->cpumask); | |
813 | if (next_cpu >= nr_cpu_ids) | |
814 | next_cpu = cpumask_first(hctx->cpumask); | |
815 | ||
816 | hctx->next_cpu = next_cpu; | |
817 | hctx->next_cpu_batch = BLK_MQ_CPU_WORK_BATCH; | |
818 | } | |
819 | ||
820 | return cpu; | |
821 | } | |
822 | ||
320ae51f JA |
823 | void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async) |
824 | { | |
5d12f905 | 825 | if (unlikely(test_bit(BLK_MQ_S_STOPPED, &hctx->state))) |
320ae51f JA |
826 | return; |
827 | ||
e4043dcf | 828 | if (!async && cpumask_test_cpu(smp_processor_id(), hctx->cpumask)) |
320ae51f | 829 | __blk_mq_run_hw_queue(hctx); |
e4043dcf | 830 | else if (hctx->queue->nr_hw_queues == 1) |
70f4db63 | 831 | kblockd_schedule_delayed_work(&hctx->run_work, 0); |
e4043dcf JA |
832 | else { |
833 | unsigned int cpu; | |
834 | ||
506e931f | 835 | cpu = blk_mq_hctx_next_cpu(hctx); |
70f4db63 | 836 | kblockd_schedule_delayed_work_on(cpu, &hctx->run_work, 0); |
e4043dcf | 837 | } |
320ae51f JA |
838 | } |
839 | ||
840 | void blk_mq_run_queues(struct request_queue *q, bool async) | |
841 | { | |
842 | struct blk_mq_hw_ctx *hctx; | |
843 | int i; | |
844 | ||
845 | queue_for_each_hw_ctx(q, hctx, i) { | |
846 | if ((!blk_mq_hctx_has_pending(hctx) && | |
847 | list_empty_careful(&hctx->dispatch)) || | |
5d12f905 | 848 | test_bit(BLK_MQ_S_STOPPED, &hctx->state)) |
320ae51f JA |
849 | continue; |
850 | ||
e4043dcf | 851 | preempt_disable(); |
320ae51f | 852 | blk_mq_run_hw_queue(hctx, async); |
e4043dcf | 853 | preempt_enable(); |
320ae51f JA |
854 | } |
855 | } | |
856 | EXPORT_SYMBOL(blk_mq_run_queues); | |
857 | ||
858 | void blk_mq_stop_hw_queue(struct blk_mq_hw_ctx *hctx) | |
859 | { | |
70f4db63 CH |
860 | cancel_delayed_work(&hctx->run_work); |
861 | cancel_delayed_work(&hctx->delay_work); | |
320ae51f JA |
862 | set_bit(BLK_MQ_S_STOPPED, &hctx->state); |
863 | } | |
864 | EXPORT_SYMBOL(blk_mq_stop_hw_queue); | |
865 | ||
280d45f6 CH |
866 | void blk_mq_stop_hw_queues(struct request_queue *q) |
867 | { | |
868 | struct blk_mq_hw_ctx *hctx; | |
869 | int i; | |
870 | ||
871 | queue_for_each_hw_ctx(q, hctx, i) | |
872 | blk_mq_stop_hw_queue(hctx); | |
873 | } | |
874 | EXPORT_SYMBOL(blk_mq_stop_hw_queues); | |
875 | ||
320ae51f JA |
876 | void blk_mq_start_hw_queue(struct blk_mq_hw_ctx *hctx) |
877 | { | |
878 | clear_bit(BLK_MQ_S_STOPPED, &hctx->state); | |
e4043dcf JA |
879 | |
880 | preempt_disable(); | |
0ffbce80 | 881 | blk_mq_run_hw_queue(hctx, false); |
e4043dcf | 882 | preempt_enable(); |
320ae51f JA |
883 | } |
884 | EXPORT_SYMBOL(blk_mq_start_hw_queue); | |
885 | ||
2f268556 CH |
886 | void blk_mq_start_hw_queues(struct request_queue *q) |
887 | { | |
888 | struct blk_mq_hw_ctx *hctx; | |
889 | int i; | |
890 | ||
891 | queue_for_each_hw_ctx(q, hctx, i) | |
892 | blk_mq_start_hw_queue(hctx); | |
893 | } | |
894 | EXPORT_SYMBOL(blk_mq_start_hw_queues); | |
895 | ||
896 | ||
1b4a3258 | 897 | void blk_mq_start_stopped_hw_queues(struct request_queue *q, bool async) |
320ae51f JA |
898 | { |
899 | struct blk_mq_hw_ctx *hctx; | |
900 | int i; | |
901 | ||
902 | queue_for_each_hw_ctx(q, hctx, i) { | |
903 | if (!test_bit(BLK_MQ_S_STOPPED, &hctx->state)) | |
904 | continue; | |
905 | ||
906 | clear_bit(BLK_MQ_S_STOPPED, &hctx->state); | |
e4043dcf | 907 | preempt_disable(); |
1b4a3258 | 908 | blk_mq_run_hw_queue(hctx, async); |
e4043dcf | 909 | preempt_enable(); |
320ae51f JA |
910 | } |
911 | } | |
912 | EXPORT_SYMBOL(blk_mq_start_stopped_hw_queues); | |
913 | ||
70f4db63 | 914 | static void blk_mq_run_work_fn(struct work_struct *work) |
320ae51f JA |
915 | { |
916 | struct blk_mq_hw_ctx *hctx; | |
917 | ||
70f4db63 | 918 | hctx = container_of(work, struct blk_mq_hw_ctx, run_work.work); |
e4043dcf | 919 | |
320ae51f JA |
920 | __blk_mq_run_hw_queue(hctx); |
921 | } | |
922 | ||
70f4db63 CH |
923 | static void blk_mq_delay_work_fn(struct work_struct *work) |
924 | { | |
925 | struct blk_mq_hw_ctx *hctx; | |
926 | ||
927 | hctx = container_of(work, struct blk_mq_hw_ctx, delay_work.work); | |
928 | ||
929 | if (test_and_clear_bit(BLK_MQ_S_STOPPED, &hctx->state)) | |
930 | __blk_mq_run_hw_queue(hctx); | |
931 | } | |
932 | ||
933 | void blk_mq_delay_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs) | |
934 | { | |
935 | unsigned long tmo = msecs_to_jiffies(msecs); | |
936 | ||
937 | if (hctx->queue->nr_hw_queues == 1) | |
938 | kblockd_schedule_delayed_work(&hctx->delay_work, tmo); | |
939 | else { | |
940 | unsigned int cpu; | |
941 | ||
506e931f | 942 | cpu = blk_mq_hctx_next_cpu(hctx); |
70f4db63 CH |
943 | kblockd_schedule_delayed_work_on(cpu, &hctx->delay_work, tmo); |
944 | } | |
945 | } | |
946 | EXPORT_SYMBOL(blk_mq_delay_queue); | |
947 | ||
320ae51f | 948 | static void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, |
72a0a36e | 949 | struct request *rq, bool at_head) |
320ae51f JA |
950 | { |
951 | struct blk_mq_ctx *ctx = rq->mq_ctx; | |
952 | ||
01b983c9 JA |
953 | trace_block_rq_insert(hctx->queue, rq); |
954 | ||
72a0a36e CH |
955 | if (at_head) |
956 | list_add(&rq->queuelist, &ctx->rq_list); | |
957 | else | |
958 | list_add_tail(&rq->queuelist, &ctx->rq_list); | |
4bb659b1 | 959 | |
320ae51f | 960 | blk_mq_hctx_mark_pending(hctx, ctx); |
320ae51f JA |
961 | } |
962 | ||
eeabc850 CH |
963 | void blk_mq_insert_request(struct request *rq, bool at_head, bool run_queue, |
964 | bool async) | |
320ae51f | 965 | { |
eeabc850 | 966 | struct request_queue *q = rq->q; |
320ae51f | 967 | struct blk_mq_hw_ctx *hctx; |
eeabc850 CH |
968 | struct blk_mq_ctx *ctx = rq->mq_ctx, *current_ctx; |
969 | ||
970 | current_ctx = blk_mq_get_ctx(q); | |
971 | if (!cpu_online(ctx->cpu)) | |
972 | rq->mq_ctx = ctx = current_ctx; | |
320ae51f | 973 | |
320ae51f JA |
974 | hctx = q->mq_ops->map_queue(q, ctx->cpu); |
975 | ||
eeabc850 CH |
976 | if (rq->cmd_flags & (REQ_FLUSH | REQ_FUA) && |
977 | !(rq->cmd_flags & (REQ_FLUSH_SEQ))) { | |
320ae51f JA |
978 | blk_insert_flush(rq); |
979 | } else { | |
320ae51f | 980 | spin_lock(&ctx->lock); |
72a0a36e | 981 | __blk_mq_insert_request(hctx, rq, at_head); |
320ae51f | 982 | spin_unlock(&ctx->lock); |
320ae51f JA |
983 | } |
984 | ||
320ae51f JA |
985 | if (run_queue) |
986 | blk_mq_run_hw_queue(hctx, async); | |
e4043dcf JA |
987 | |
988 | blk_mq_put_ctx(current_ctx); | |
320ae51f JA |
989 | } |
990 | ||
991 | static void blk_mq_insert_requests(struct request_queue *q, | |
992 | struct blk_mq_ctx *ctx, | |
993 | struct list_head *list, | |
994 | int depth, | |
995 | bool from_schedule) | |
996 | ||
997 | { | |
998 | struct blk_mq_hw_ctx *hctx; | |
999 | struct blk_mq_ctx *current_ctx; | |
1000 | ||
1001 | trace_block_unplug(q, depth, !from_schedule); | |
1002 | ||
1003 | current_ctx = blk_mq_get_ctx(q); | |
1004 | ||
1005 | if (!cpu_online(ctx->cpu)) | |
1006 | ctx = current_ctx; | |
1007 | hctx = q->mq_ops->map_queue(q, ctx->cpu); | |
1008 | ||
1009 | /* | |
1010 | * preemption doesn't flush plug list, so it's possible ctx->cpu is | |
1011 | * offline now | |
1012 | */ | |
1013 | spin_lock(&ctx->lock); | |
1014 | while (!list_empty(list)) { | |
1015 | struct request *rq; | |
1016 | ||
1017 | rq = list_first_entry(list, struct request, queuelist); | |
1018 | list_del_init(&rq->queuelist); | |
1019 | rq->mq_ctx = ctx; | |
72a0a36e | 1020 | __blk_mq_insert_request(hctx, rq, false); |
320ae51f JA |
1021 | } |
1022 | spin_unlock(&ctx->lock); | |
1023 | ||
320ae51f | 1024 | blk_mq_run_hw_queue(hctx, from_schedule); |
e4043dcf | 1025 | blk_mq_put_ctx(current_ctx); |
320ae51f JA |
1026 | } |
1027 | ||
1028 | static int plug_ctx_cmp(void *priv, struct list_head *a, struct list_head *b) | |
1029 | { | |
1030 | struct request *rqa = container_of(a, struct request, queuelist); | |
1031 | struct request *rqb = container_of(b, struct request, queuelist); | |
1032 | ||
1033 | return !(rqa->mq_ctx < rqb->mq_ctx || | |
1034 | (rqa->mq_ctx == rqb->mq_ctx && | |
1035 | blk_rq_pos(rqa) < blk_rq_pos(rqb))); | |
1036 | } | |
1037 | ||
1038 | void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule) | |
1039 | { | |
1040 | struct blk_mq_ctx *this_ctx; | |
1041 | struct request_queue *this_q; | |
1042 | struct request *rq; | |
1043 | LIST_HEAD(list); | |
1044 | LIST_HEAD(ctx_list); | |
1045 | unsigned int depth; | |
1046 | ||
1047 | list_splice_init(&plug->mq_list, &list); | |
1048 | ||
1049 | list_sort(NULL, &list, plug_ctx_cmp); | |
1050 | ||
1051 | this_q = NULL; | |
1052 | this_ctx = NULL; | |
1053 | depth = 0; | |
1054 | ||
1055 | while (!list_empty(&list)) { | |
1056 | rq = list_entry_rq(list.next); | |
1057 | list_del_init(&rq->queuelist); | |
1058 | BUG_ON(!rq->q); | |
1059 | if (rq->mq_ctx != this_ctx) { | |
1060 | if (this_ctx) { | |
1061 | blk_mq_insert_requests(this_q, this_ctx, | |
1062 | &ctx_list, depth, | |
1063 | from_schedule); | |
1064 | } | |
1065 | ||
1066 | this_ctx = rq->mq_ctx; | |
1067 | this_q = rq->q; | |
1068 | depth = 0; | |
1069 | } | |
1070 | ||
1071 | depth++; | |
1072 | list_add_tail(&rq->queuelist, &ctx_list); | |
1073 | } | |
1074 | ||
1075 | /* | |
1076 | * If 'this_ctx' is set, we know we have entries to complete | |
1077 | * on 'ctx_list'. Do those. | |
1078 | */ | |
1079 | if (this_ctx) { | |
1080 | blk_mq_insert_requests(this_q, this_ctx, &ctx_list, depth, | |
1081 | from_schedule); | |
1082 | } | |
1083 | } | |
1084 | ||
1085 | static void blk_mq_bio_to_request(struct request *rq, struct bio *bio) | |
1086 | { | |
1087 | init_request_from_bio(rq, bio); | |
4b570521 | 1088 | |
3ee32372 | 1089 | if (blk_do_io_stat(rq)) |
4b570521 | 1090 | blk_account_io_start(rq, 1); |
320ae51f JA |
1091 | } |
1092 | ||
07068d5b JA |
1093 | static inline bool blk_mq_merge_queue_io(struct blk_mq_hw_ctx *hctx, |
1094 | struct blk_mq_ctx *ctx, | |
1095 | struct request *rq, struct bio *bio) | |
320ae51f | 1096 | { |
07068d5b | 1097 | struct request_queue *q = hctx->queue; |
320ae51f | 1098 | |
07068d5b JA |
1099 | if (!(hctx->flags & BLK_MQ_F_SHOULD_MERGE)) { |
1100 | blk_mq_bio_to_request(rq, bio); | |
1101 | spin_lock(&ctx->lock); | |
1102 | insert_rq: | |
1103 | __blk_mq_insert_request(hctx, rq, false); | |
1104 | spin_unlock(&ctx->lock); | |
1105 | return false; | |
1106 | } else { | |
1107 | spin_lock(&ctx->lock); | |
1108 | if (!blk_mq_attempt_merge(q, ctx, bio)) { | |
1109 | blk_mq_bio_to_request(rq, bio); | |
1110 | goto insert_rq; | |
1111 | } | |
320ae51f | 1112 | |
07068d5b JA |
1113 | spin_unlock(&ctx->lock); |
1114 | __blk_mq_free_request(hctx, ctx, rq); | |
1115 | return true; | |
14ec77f3 | 1116 | } |
07068d5b | 1117 | } |
14ec77f3 | 1118 | |
07068d5b JA |
1119 | struct blk_map_ctx { |
1120 | struct blk_mq_hw_ctx *hctx; | |
1121 | struct blk_mq_ctx *ctx; | |
1122 | }; | |
1123 | ||
1124 | static struct request *blk_mq_map_request(struct request_queue *q, | |
1125 | struct bio *bio, | |
1126 | struct blk_map_ctx *data) | |
1127 | { | |
1128 | struct blk_mq_hw_ctx *hctx; | |
1129 | struct blk_mq_ctx *ctx; | |
1130 | struct request *rq; | |
1131 | int rw = bio_data_dir(bio); | |
cb96a42c | 1132 | struct blk_mq_alloc_data alloc_data; |
320ae51f | 1133 | |
07068d5b | 1134 | if (unlikely(blk_mq_queue_enter(q))) { |
320ae51f | 1135 | bio_endio(bio, -EIO); |
07068d5b | 1136 | return NULL; |
320ae51f JA |
1137 | } |
1138 | ||
1139 | ctx = blk_mq_get_ctx(q); | |
1140 | hctx = q->mq_ops->map_queue(q, ctx->cpu); | |
1141 | ||
07068d5b | 1142 | if (rw_is_sync(bio->bi_rw)) |
27fbf4e8 | 1143 | rw |= REQ_SYNC; |
07068d5b | 1144 | |
320ae51f | 1145 | trace_block_getrq(q, bio, rw); |
cb96a42c ML |
1146 | blk_mq_set_alloc_data(&alloc_data, q, GFP_ATOMIC, false, ctx, |
1147 | hctx); | |
1148 | rq = __blk_mq_alloc_request(&alloc_data, rw); | |
5dee8577 | 1149 | if (unlikely(!rq)) { |
793597a6 | 1150 | __blk_mq_run_hw_queue(hctx); |
320ae51f JA |
1151 | blk_mq_put_ctx(ctx); |
1152 | trace_block_sleeprq(q, bio, rw); | |
793597a6 CH |
1153 | |
1154 | ctx = blk_mq_get_ctx(q); | |
320ae51f | 1155 | hctx = q->mq_ops->map_queue(q, ctx->cpu); |
cb96a42c ML |
1156 | blk_mq_set_alloc_data(&alloc_data, q, |
1157 | __GFP_WAIT|GFP_ATOMIC, false, ctx, hctx); | |
1158 | rq = __blk_mq_alloc_request(&alloc_data, rw); | |
1159 | ctx = alloc_data.ctx; | |
1160 | hctx = alloc_data.hctx; | |
320ae51f JA |
1161 | } |
1162 | ||
1163 | hctx->queued++; | |
07068d5b JA |
1164 | data->hctx = hctx; |
1165 | data->ctx = ctx; | |
1166 | return rq; | |
1167 | } | |
1168 | ||
1169 | /* | |
1170 | * Multiple hardware queue variant. This will not use per-process plugs, | |
1171 | * but will attempt to bypass the hctx queueing if we can go straight to | |
1172 | * hardware for SYNC IO. | |
1173 | */ | |
1174 | static void blk_mq_make_request(struct request_queue *q, struct bio *bio) | |
1175 | { | |
1176 | const int is_sync = rw_is_sync(bio->bi_rw); | |
1177 | const int is_flush_fua = bio->bi_rw & (REQ_FLUSH | REQ_FUA); | |
1178 | struct blk_map_ctx data; | |
1179 | struct request *rq; | |
1180 | ||
1181 | blk_queue_bounce(q, &bio); | |
1182 | ||
1183 | if (bio_integrity_enabled(bio) && bio_integrity_prep(bio)) { | |
1184 | bio_endio(bio, -EIO); | |
1185 | return; | |
1186 | } | |
1187 | ||
1188 | rq = blk_mq_map_request(q, bio, &data); | |
1189 | if (unlikely(!rq)) | |
1190 | return; | |
1191 | ||
1192 | if (unlikely(is_flush_fua)) { | |
1193 | blk_mq_bio_to_request(rq, bio); | |
1194 | blk_insert_flush(rq); | |
1195 | goto run_queue; | |
1196 | } | |
1197 | ||
1198 | if (is_sync) { | |
1199 | int ret; | |
1200 | ||
1201 | blk_mq_bio_to_request(rq, bio); | |
1202 | blk_mq_start_request(rq, true); | |
1203 | ||
1204 | /* | |
1205 | * For OK queue, we are done. For error, kill it. Any other | |
1206 | * error (busy), just add it to our list as we previously | |
1207 | * would have done | |
1208 | */ | |
1209 | ret = q->mq_ops->queue_rq(data.hctx, rq); | |
1210 | if (ret == BLK_MQ_RQ_QUEUE_OK) | |
1211 | goto done; | |
1212 | else { | |
1213 | __blk_mq_requeue_request(rq); | |
1214 | ||
1215 | if (ret == BLK_MQ_RQ_QUEUE_ERROR) { | |
1216 | rq->errors = -EIO; | |
1217 | blk_mq_end_io(rq, rq->errors); | |
1218 | goto done; | |
1219 | } | |
1220 | } | |
1221 | } | |
1222 | ||
1223 | if (!blk_mq_merge_queue_io(data.hctx, data.ctx, rq, bio)) { | |
1224 | /* | |
1225 | * For a SYNC request, send it to the hardware immediately. For | |
1226 | * an ASYNC request, just ensure that we run it later on. The | |
1227 | * latter allows for merging opportunities and more efficient | |
1228 | * dispatching. | |
1229 | */ | |
1230 | run_queue: | |
1231 | blk_mq_run_hw_queue(data.hctx, !is_sync || is_flush_fua); | |
1232 | } | |
1233 | done: | |
1234 | blk_mq_put_ctx(data.ctx); | |
1235 | } | |
1236 | ||
1237 | /* | |
1238 | * Single hardware queue variant. This will attempt to use any per-process | |
1239 | * plug for merging and IO deferral. | |
1240 | */ | |
1241 | static void blk_sq_make_request(struct request_queue *q, struct bio *bio) | |
1242 | { | |
1243 | const int is_sync = rw_is_sync(bio->bi_rw); | |
1244 | const int is_flush_fua = bio->bi_rw & (REQ_FLUSH | REQ_FUA); | |
1245 | unsigned int use_plug, request_count = 0; | |
1246 | struct blk_map_ctx data; | |
1247 | struct request *rq; | |
1248 | ||
1249 | /* | |
1250 | * If we have multiple hardware queues, just go directly to | |
1251 | * one of those for sync IO. | |
1252 | */ | |
1253 | use_plug = !is_flush_fua && !is_sync; | |
1254 | ||
1255 | blk_queue_bounce(q, &bio); | |
1256 | ||
1257 | if (bio_integrity_enabled(bio) && bio_integrity_prep(bio)) { | |
1258 | bio_endio(bio, -EIO); | |
1259 | return; | |
1260 | } | |
1261 | ||
1262 | if (use_plug && !blk_queue_nomerges(q) && | |
1263 | blk_attempt_plug_merge(q, bio, &request_count)) | |
1264 | return; | |
1265 | ||
1266 | rq = blk_mq_map_request(q, bio, &data); | |
ff87bcec JA |
1267 | if (unlikely(!rq)) |
1268 | return; | |
320ae51f JA |
1269 | |
1270 | if (unlikely(is_flush_fua)) { | |
1271 | blk_mq_bio_to_request(rq, bio); | |
320ae51f JA |
1272 | blk_insert_flush(rq); |
1273 | goto run_queue; | |
1274 | } | |
1275 | ||
1276 | /* | |
1277 | * A task plug currently exists. Since this is completely lockless, | |
1278 | * utilize that to temporarily store requests until the task is | |
1279 | * either done or scheduled away. | |
1280 | */ | |
1281 | if (use_plug) { | |
1282 | struct blk_plug *plug = current->plug; | |
1283 | ||
1284 | if (plug) { | |
1285 | blk_mq_bio_to_request(rq, bio); | |
92f399c7 | 1286 | if (list_empty(&plug->mq_list)) |
320ae51f JA |
1287 | trace_block_plug(q); |
1288 | else if (request_count >= BLK_MAX_REQUEST_COUNT) { | |
1289 | blk_flush_plug_list(plug, false); | |
1290 | trace_block_plug(q); | |
1291 | } | |
1292 | list_add_tail(&rq->queuelist, &plug->mq_list); | |
07068d5b | 1293 | blk_mq_put_ctx(data.ctx); |
320ae51f JA |
1294 | return; |
1295 | } | |
1296 | } | |
1297 | ||
07068d5b JA |
1298 | if (!blk_mq_merge_queue_io(data.hctx, data.ctx, rq, bio)) { |
1299 | /* | |
1300 | * For a SYNC request, send it to the hardware immediately. For | |
1301 | * an ASYNC request, just ensure that we run it later on. The | |
1302 | * latter allows for merging opportunities and more efficient | |
1303 | * dispatching. | |
1304 | */ | |
1305 | run_queue: | |
1306 | blk_mq_run_hw_queue(data.hctx, !is_sync || is_flush_fua); | |
320ae51f JA |
1307 | } |
1308 | ||
07068d5b | 1309 | blk_mq_put_ctx(data.ctx); |
320ae51f JA |
1310 | } |
1311 | ||
1312 | /* | |
1313 | * Default mapping to a software queue, since we use one per CPU. | |
1314 | */ | |
1315 | struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q, const int cpu) | |
1316 | { | |
1317 | return q->queue_hw_ctx[q->mq_map[cpu]]; | |
1318 | } | |
1319 | EXPORT_SYMBOL(blk_mq_map_queue); | |
1320 | ||
24d2f903 CH |
1321 | static void blk_mq_free_rq_map(struct blk_mq_tag_set *set, |
1322 | struct blk_mq_tags *tags, unsigned int hctx_idx) | |
95363efd | 1323 | { |
e9b267d9 | 1324 | struct page *page; |
320ae51f | 1325 | |
24d2f903 | 1326 | if (tags->rqs && set->ops->exit_request) { |
e9b267d9 | 1327 | int i; |
320ae51f | 1328 | |
24d2f903 CH |
1329 | for (i = 0; i < tags->nr_tags; i++) { |
1330 | if (!tags->rqs[i]) | |
e9b267d9 | 1331 | continue; |
24d2f903 CH |
1332 | set->ops->exit_request(set->driver_data, tags->rqs[i], |
1333 | hctx_idx, i); | |
e9b267d9 | 1334 | } |
320ae51f | 1335 | } |
320ae51f | 1336 | |
24d2f903 CH |
1337 | while (!list_empty(&tags->page_list)) { |
1338 | page = list_first_entry(&tags->page_list, struct page, lru); | |
6753471c | 1339 | list_del_init(&page->lru); |
320ae51f JA |
1340 | __free_pages(page, page->private); |
1341 | } | |
1342 | ||
24d2f903 | 1343 | kfree(tags->rqs); |
320ae51f | 1344 | |
24d2f903 | 1345 | blk_mq_free_tags(tags); |
320ae51f JA |
1346 | } |
1347 | ||
1348 | static size_t order_to_size(unsigned int order) | |
1349 | { | |
4ca08500 | 1350 | return (size_t)PAGE_SIZE << order; |
320ae51f JA |
1351 | } |
1352 | ||
24d2f903 CH |
1353 | static struct blk_mq_tags *blk_mq_init_rq_map(struct blk_mq_tag_set *set, |
1354 | unsigned int hctx_idx) | |
320ae51f | 1355 | { |
24d2f903 | 1356 | struct blk_mq_tags *tags; |
320ae51f JA |
1357 | unsigned int i, j, entries_per_page, max_order = 4; |
1358 | size_t rq_size, left; | |
1359 | ||
24d2f903 CH |
1360 | tags = blk_mq_init_tags(set->queue_depth, set->reserved_tags, |
1361 | set->numa_node); | |
1362 | if (!tags) | |
1363 | return NULL; | |
320ae51f | 1364 | |
24d2f903 CH |
1365 | INIT_LIST_HEAD(&tags->page_list); |
1366 | ||
1367 | tags->rqs = kmalloc_node(set->queue_depth * sizeof(struct request *), | |
1368 | GFP_KERNEL, set->numa_node); | |
1369 | if (!tags->rqs) { | |
1370 | blk_mq_free_tags(tags); | |
1371 | return NULL; | |
1372 | } | |
320ae51f JA |
1373 | |
1374 | /* | |
1375 | * rq_size is the size of the request plus driver payload, rounded | |
1376 | * to the cacheline size | |
1377 | */ | |
24d2f903 | 1378 | rq_size = round_up(sizeof(struct request) + set->cmd_size, |
320ae51f | 1379 | cache_line_size()); |
24d2f903 | 1380 | left = rq_size * set->queue_depth; |
320ae51f | 1381 | |
24d2f903 | 1382 | for (i = 0; i < set->queue_depth; ) { |
320ae51f JA |
1383 | int this_order = max_order; |
1384 | struct page *page; | |
1385 | int to_do; | |
1386 | void *p; | |
1387 | ||
1388 | while (left < order_to_size(this_order - 1) && this_order) | |
1389 | this_order--; | |
1390 | ||
1391 | do { | |
24d2f903 CH |
1392 | page = alloc_pages_node(set->numa_node, GFP_KERNEL, |
1393 | this_order); | |
320ae51f JA |
1394 | if (page) |
1395 | break; | |
1396 | if (!this_order--) | |
1397 | break; | |
1398 | if (order_to_size(this_order) < rq_size) | |
1399 | break; | |
1400 | } while (1); | |
1401 | ||
1402 | if (!page) | |
24d2f903 | 1403 | goto fail; |
320ae51f JA |
1404 | |
1405 | page->private = this_order; | |
24d2f903 | 1406 | list_add_tail(&page->lru, &tags->page_list); |
320ae51f JA |
1407 | |
1408 | p = page_address(page); | |
1409 | entries_per_page = order_to_size(this_order) / rq_size; | |
24d2f903 | 1410 | to_do = min(entries_per_page, set->queue_depth - i); |
320ae51f JA |
1411 | left -= to_do * rq_size; |
1412 | for (j = 0; j < to_do; j++) { | |
24d2f903 CH |
1413 | tags->rqs[i] = p; |
1414 | if (set->ops->init_request) { | |
1415 | if (set->ops->init_request(set->driver_data, | |
1416 | tags->rqs[i], hctx_idx, i, | |
1417 | set->numa_node)) | |
1418 | goto fail; | |
e9b267d9 CH |
1419 | } |
1420 | ||
320ae51f JA |
1421 | p += rq_size; |
1422 | i++; | |
1423 | } | |
1424 | } | |
1425 | ||
24d2f903 | 1426 | return tags; |
320ae51f | 1427 | |
24d2f903 CH |
1428 | fail: |
1429 | pr_warn("%s: failed to allocate requests\n", __func__); | |
1430 | blk_mq_free_rq_map(set, tags, hctx_idx); | |
1431 | return NULL; | |
320ae51f JA |
1432 | } |
1433 | ||
1429d7c9 JA |
1434 | static void blk_mq_free_bitmap(struct blk_mq_ctxmap *bitmap) |
1435 | { | |
1436 | kfree(bitmap->map); | |
1437 | } | |
1438 | ||
1439 | static int blk_mq_alloc_bitmap(struct blk_mq_ctxmap *bitmap, int node) | |
1440 | { | |
1441 | unsigned int bpw = 8, total, num_maps, i; | |
1442 | ||
1443 | bitmap->bits_per_word = bpw; | |
1444 | ||
1445 | num_maps = ALIGN(nr_cpu_ids, bpw) / bpw; | |
1446 | bitmap->map = kzalloc_node(num_maps * sizeof(struct blk_align_bitmap), | |
1447 | GFP_KERNEL, node); | |
1448 | if (!bitmap->map) | |
1449 | return -ENOMEM; | |
1450 | ||
1451 | bitmap->map_size = num_maps; | |
1452 | ||
1453 | total = nr_cpu_ids; | |
1454 | for (i = 0; i < num_maps; i++) { | |
1455 | bitmap->map[i].depth = min(total, bitmap->bits_per_word); | |
1456 | total -= bitmap->map[i].depth; | |
1457 | } | |
1458 | ||
1459 | return 0; | |
1460 | } | |
1461 | ||
484b4061 JA |
1462 | static int blk_mq_hctx_cpu_offline(struct blk_mq_hw_ctx *hctx, int cpu) |
1463 | { | |
1464 | struct request_queue *q = hctx->queue; | |
1465 | struct blk_mq_ctx *ctx; | |
1466 | LIST_HEAD(tmp); | |
1467 | ||
1468 | /* | |
1469 | * Move ctx entries to new CPU, if this one is going away. | |
1470 | */ | |
1471 | ctx = __blk_mq_get_ctx(q, cpu); | |
1472 | ||
1473 | spin_lock(&ctx->lock); | |
1474 | if (!list_empty(&ctx->rq_list)) { | |
1475 | list_splice_init(&ctx->rq_list, &tmp); | |
1476 | blk_mq_hctx_clear_pending(hctx, ctx); | |
1477 | } | |
1478 | spin_unlock(&ctx->lock); | |
1479 | ||
1480 | if (list_empty(&tmp)) | |
1481 | return NOTIFY_OK; | |
1482 | ||
1483 | ctx = blk_mq_get_ctx(q); | |
1484 | spin_lock(&ctx->lock); | |
1485 | ||
1486 | while (!list_empty(&tmp)) { | |
1487 | struct request *rq; | |
1488 | ||
1489 | rq = list_first_entry(&tmp, struct request, queuelist); | |
1490 | rq->mq_ctx = ctx; | |
1491 | list_move_tail(&rq->queuelist, &ctx->rq_list); | |
1492 | } | |
1493 | ||
1494 | hctx = q->mq_ops->map_queue(q, ctx->cpu); | |
1495 | blk_mq_hctx_mark_pending(hctx, ctx); | |
1496 | ||
1497 | spin_unlock(&ctx->lock); | |
1498 | ||
1499 | blk_mq_run_hw_queue(hctx, true); | |
1500 | blk_mq_put_ctx(ctx); | |
1501 | return NOTIFY_OK; | |
1502 | } | |
1503 | ||
1504 | static int blk_mq_hctx_cpu_online(struct blk_mq_hw_ctx *hctx, int cpu) | |
1505 | { | |
1506 | struct request_queue *q = hctx->queue; | |
1507 | struct blk_mq_tag_set *set = q->tag_set; | |
1508 | ||
1509 | if (set->tags[hctx->queue_num]) | |
1510 | return NOTIFY_OK; | |
1511 | ||
1512 | set->tags[hctx->queue_num] = blk_mq_init_rq_map(set, hctx->queue_num); | |
1513 | if (!set->tags[hctx->queue_num]) | |
1514 | return NOTIFY_STOP; | |
1515 | ||
1516 | hctx->tags = set->tags[hctx->queue_num]; | |
1517 | return NOTIFY_OK; | |
1518 | } | |
1519 | ||
1520 | static int blk_mq_hctx_notify(void *data, unsigned long action, | |
1521 | unsigned int cpu) | |
1522 | { | |
1523 | struct blk_mq_hw_ctx *hctx = data; | |
1524 | ||
1525 | if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) | |
1526 | return blk_mq_hctx_cpu_offline(hctx, cpu); | |
1527 | else if (action == CPU_ONLINE || action == CPU_ONLINE_FROZEN) | |
1528 | return blk_mq_hctx_cpu_online(hctx, cpu); | |
1529 | ||
1530 | return NOTIFY_OK; | |
1531 | } | |
1532 | ||
624dbe47 ML |
1533 | static void blk_mq_exit_hw_queues(struct request_queue *q, |
1534 | struct blk_mq_tag_set *set, int nr_queue) | |
1535 | { | |
1536 | struct blk_mq_hw_ctx *hctx; | |
1537 | unsigned int i; | |
1538 | ||
1539 | queue_for_each_hw_ctx(q, hctx, i) { | |
1540 | if (i == nr_queue) | |
1541 | break; | |
1542 | ||
f899fed4 JA |
1543 | blk_mq_tag_idle(hctx); |
1544 | ||
624dbe47 ML |
1545 | if (set->ops->exit_hctx) |
1546 | set->ops->exit_hctx(hctx, i); | |
1547 | ||
1548 | blk_mq_unregister_cpu_notifier(&hctx->cpu_notifier); | |
1549 | kfree(hctx->ctxs); | |
1550 | blk_mq_free_bitmap(&hctx->ctx_map); | |
1551 | } | |
1552 | ||
1553 | } | |
1554 | ||
1555 | static void blk_mq_free_hw_queues(struct request_queue *q, | |
1556 | struct blk_mq_tag_set *set) | |
1557 | { | |
1558 | struct blk_mq_hw_ctx *hctx; | |
1559 | unsigned int i; | |
1560 | ||
1561 | queue_for_each_hw_ctx(q, hctx, i) { | |
1562 | free_cpumask_var(hctx->cpumask); | |
cdef54dd | 1563 | kfree(hctx); |
624dbe47 ML |
1564 | } |
1565 | } | |
1566 | ||
320ae51f | 1567 | static int blk_mq_init_hw_queues(struct request_queue *q, |
24d2f903 | 1568 | struct blk_mq_tag_set *set) |
320ae51f JA |
1569 | { |
1570 | struct blk_mq_hw_ctx *hctx; | |
624dbe47 | 1571 | unsigned int i; |
320ae51f JA |
1572 | |
1573 | /* | |
1574 | * Initialize hardware queues | |
1575 | */ | |
1576 | queue_for_each_hw_ctx(q, hctx, i) { | |
320ae51f JA |
1577 | int node; |
1578 | ||
1579 | node = hctx->numa_node; | |
1580 | if (node == NUMA_NO_NODE) | |
24d2f903 | 1581 | node = hctx->numa_node = set->numa_node; |
320ae51f | 1582 | |
70f4db63 CH |
1583 | INIT_DELAYED_WORK(&hctx->run_work, blk_mq_run_work_fn); |
1584 | INIT_DELAYED_WORK(&hctx->delay_work, blk_mq_delay_work_fn); | |
320ae51f JA |
1585 | spin_lock_init(&hctx->lock); |
1586 | INIT_LIST_HEAD(&hctx->dispatch); | |
1587 | hctx->queue = q; | |
1588 | hctx->queue_num = i; | |
24d2f903 CH |
1589 | hctx->flags = set->flags; |
1590 | hctx->cmd_size = set->cmd_size; | |
320ae51f JA |
1591 | |
1592 | blk_mq_init_cpu_notifier(&hctx->cpu_notifier, | |
1593 | blk_mq_hctx_notify, hctx); | |
1594 | blk_mq_register_cpu_notifier(&hctx->cpu_notifier); | |
1595 | ||
24d2f903 | 1596 | hctx->tags = set->tags[i]; |
320ae51f JA |
1597 | |
1598 | /* | |
1599 | * Allocate space for all possible cpus to avoid allocation in | |
1600 | * runtime | |
1601 | */ | |
1602 | hctx->ctxs = kmalloc_node(nr_cpu_ids * sizeof(void *), | |
1603 | GFP_KERNEL, node); | |
1604 | if (!hctx->ctxs) | |
1605 | break; | |
1606 | ||
1429d7c9 | 1607 | if (blk_mq_alloc_bitmap(&hctx->ctx_map, node)) |
320ae51f JA |
1608 | break; |
1609 | ||
320ae51f JA |
1610 | hctx->nr_ctx = 0; |
1611 | ||
24d2f903 CH |
1612 | if (set->ops->init_hctx && |
1613 | set->ops->init_hctx(hctx, set->driver_data, i)) | |
320ae51f JA |
1614 | break; |
1615 | } | |
1616 | ||
1617 | if (i == q->nr_hw_queues) | |
1618 | return 0; | |
1619 | ||
1620 | /* | |
1621 | * Init failed | |
1622 | */ | |
624dbe47 | 1623 | blk_mq_exit_hw_queues(q, set, i); |
320ae51f JA |
1624 | |
1625 | return 1; | |
1626 | } | |
1627 | ||
1628 | static void blk_mq_init_cpu_queues(struct request_queue *q, | |
1629 | unsigned int nr_hw_queues) | |
1630 | { | |
1631 | unsigned int i; | |
1632 | ||
1633 | for_each_possible_cpu(i) { | |
1634 | struct blk_mq_ctx *__ctx = per_cpu_ptr(q->queue_ctx, i); | |
1635 | struct blk_mq_hw_ctx *hctx; | |
1636 | ||
1637 | memset(__ctx, 0, sizeof(*__ctx)); | |
1638 | __ctx->cpu = i; | |
1639 | spin_lock_init(&__ctx->lock); | |
1640 | INIT_LIST_HEAD(&__ctx->rq_list); | |
1641 | __ctx->queue = q; | |
1642 | ||
1643 | /* If the cpu isn't online, the cpu is mapped to first hctx */ | |
320ae51f JA |
1644 | if (!cpu_online(i)) |
1645 | continue; | |
1646 | ||
e4043dcf JA |
1647 | hctx = q->mq_ops->map_queue(q, i); |
1648 | cpumask_set_cpu(i, hctx->cpumask); | |
1649 | hctx->nr_ctx++; | |
1650 | ||
320ae51f JA |
1651 | /* |
1652 | * Set local node, IFF we have more than one hw queue. If | |
1653 | * not, we remain on the home node of the device | |
1654 | */ | |
1655 | if (nr_hw_queues > 1 && hctx->numa_node == NUMA_NO_NODE) | |
1656 | hctx->numa_node = cpu_to_node(i); | |
1657 | } | |
1658 | } | |
1659 | ||
1660 | static void blk_mq_map_swqueue(struct request_queue *q) | |
1661 | { | |
1662 | unsigned int i; | |
1663 | struct blk_mq_hw_ctx *hctx; | |
1664 | struct blk_mq_ctx *ctx; | |
1665 | ||
1666 | queue_for_each_hw_ctx(q, hctx, i) { | |
e4043dcf | 1667 | cpumask_clear(hctx->cpumask); |
320ae51f JA |
1668 | hctx->nr_ctx = 0; |
1669 | } | |
1670 | ||
1671 | /* | |
1672 | * Map software to hardware queues | |
1673 | */ | |
1674 | queue_for_each_ctx(q, ctx, i) { | |
1675 | /* If the cpu isn't online, the cpu is mapped to first hctx */ | |
e4043dcf JA |
1676 | if (!cpu_online(i)) |
1677 | continue; | |
1678 | ||
320ae51f | 1679 | hctx = q->mq_ops->map_queue(q, i); |
e4043dcf | 1680 | cpumask_set_cpu(i, hctx->cpumask); |
320ae51f JA |
1681 | ctx->index_hw = hctx->nr_ctx; |
1682 | hctx->ctxs[hctx->nr_ctx++] = ctx; | |
1683 | } | |
506e931f JA |
1684 | |
1685 | queue_for_each_hw_ctx(q, hctx, i) { | |
484b4061 JA |
1686 | /* |
1687 | * If not software queues are mapped to this hardware queue, | |
1688 | * disable it and free the request entries | |
1689 | */ | |
1690 | if (!hctx->nr_ctx) { | |
1691 | struct blk_mq_tag_set *set = q->tag_set; | |
1692 | ||
1693 | if (set->tags[i]) { | |
1694 | blk_mq_free_rq_map(set, set->tags[i], i); | |
1695 | set->tags[i] = NULL; | |
1696 | hctx->tags = NULL; | |
1697 | } | |
1698 | continue; | |
1699 | } | |
1700 | ||
1701 | /* | |
1702 | * Initialize batch roundrobin counts | |
1703 | */ | |
506e931f JA |
1704 | hctx->next_cpu = cpumask_first(hctx->cpumask); |
1705 | hctx->next_cpu_batch = BLK_MQ_CPU_WORK_BATCH; | |
1706 | } | |
320ae51f JA |
1707 | } |
1708 | ||
0d2602ca JA |
1709 | static void blk_mq_update_tag_set_depth(struct blk_mq_tag_set *set) |
1710 | { | |
1711 | struct blk_mq_hw_ctx *hctx; | |
1712 | struct request_queue *q; | |
1713 | bool shared; | |
1714 | int i; | |
1715 | ||
1716 | if (set->tag_list.next == set->tag_list.prev) | |
1717 | shared = false; | |
1718 | else | |
1719 | shared = true; | |
1720 | ||
1721 | list_for_each_entry(q, &set->tag_list, tag_set_list) { | |
1722 | blk_mq_freeze_queue(q); | |
1723 | ||
1724 | queue_for_each_hw_ctx(q, hctx, i) { | |
1725 | if (shared) | |
1726 | hctx->flags |= BLK_MQ_F_TAG_SHARED; | |
1727 | else | |
1728 | hctx->flags &= ~BLK_MQ_F_TAG_SHARED; | |
1729 | } | |
1730 | blk_mq_unfreeze_queue(q); | |
1731 | } | |
1732 | } | |
1733 | ||
1734 | static void blk_mq_del_queue_tag_set(struct request_queue *q) | |
1735 | { | |
1736 | struct blk_mq_tag_set *set = q->tag_set; | |
1737 | ||
1738 | blk_mq_freeze_queue(q); | |
1739 | ||
1740 | mutex_lock(&set->tag_list_lock); | |
1741 | list_del_init(&q->tag_set_list); | |
1742 | blk_mq_update_tag_set_depth(set); | |
1743 | mutex_unlock(&set->tag_list_lock); | |
1744 | ||
1745 | blk_mq_unfreeze_queue(q); | |
1746 | } | |
1747 | ||
1748 | static void blk_mq_add_queue_tag_set(struct blk_mq_tag_set *set, | |
1749 | struct request_queue *q) | |
1750 | { | |
1751 | q->tag_set = set; | |
1752 | ||
1753 | mutex_lock(&set->tag_list_lock); | |
1754 | list_add_tail(&q->tag_set_list, &set->tag_list); | |
1755 | blk_mq_update_tag_set_depth(set); | |
1756 | mutex_unlock(&set->tag_list_lock); | |
1757 | } | |
1758 | ||
24d2f903 | 1759 | struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *set) |
320ae51f JA |
1760 | { |
1761 | struct blk_mq_hw_ctx **hctxs; | |
e6cdb092 | 1762 | struct blk_mq_ctx __percpu *ctx; |
320ae51f | 1763 | struct request_queue *q; |
f14bbe77 | 1764 | unsigned int *map; |
320ae51f JA |
1765 | int i; |
1766 | ||
320ae51f JA |
1767 | ctx = alloc_percpu(struct blk_mq_ctx); |
1768 | if (!ctx) | |
1769 | return ERR_PTR(-ENOMEM); | |
1770 | ||
24d2f903 CH |
1771 | hctxs = kmalloc_node(set->nr_hw_queues * sizeof(*hctxs), GFP_KERNEL, |
1772 | set->numa_node); | |
320ae51f JA |
1773 | |
1774 | if (!hctxs) | |
1775 | goto err_percpu; | |
1776 | ||
f14bbe77 JA |
1777 | map = blk_mq_make_queue_map(set); |
1778 | if (!map) | |
1779 | goto err_map; | |
1780 | ||
24d2f903 | 1781 | for (i = 0; i < set->nr_hw_queues; i++) { |
f14bbe77 JA |
1782 | int node = blk_mq_hw_queue_to_node(map, i); |
1783 | ||
cdef54dd CH |
1784 | hctxs[i] = kzalloc_node(sizeof(struct blk_mq_hw_ctx), |
1785 | GFP_KERNEL, node); | |
320ae51f JA |
1786 | if (!hctxs[i]) |
1787 | goto err_hctxs; | |
1788 | ||
e4043dcf JA |
1789 | if (!zalloc_cpumask_var(&hctxs[i]->cpumask, GFP_KERNEL)) |
1790 | goto err_hctxs; | |
1791 | ||
0d2602ca | 1792 | atomic_set(&hctxs[i]->nr_active, 0); |
f14bbe77 | 1793 | hctxs[i]->numa_node = node; |
320ae51f JA |
1794 | hctxs[i]->queue_num = i; |
1795 | } | |
1796 | ||
24d2f903 | 1797 | q = blk_alloc_queue_node(GFP_KERNEL, set->numa_node); |
320ae51f JA |
1798 | if (!q) |
1799 | goto err_hctxs; | |
1800 | ||
3d2936f4 ML |
1801 | if (percpu_counter_init(&q->mq_usage_counter, 0)) |
1802 | goto err_map; | |
1803 | ||
320ae51f JA |
1804 | setup_timer(&q->timeout, blk_mq_rq_timer, (unsigned long) q); |
1805 | blk_queue_rq_timeout(q, 30000); | |
1806 | ||
1807 | q->nr_queues = nr_cpu_ids; | |
24d2f903 | 1808 | q->nr_hw_queues = set->nr_hw_queues; |
f14bbe77 | 1809 | q->mq_map = map; |
320ae51f JA |
1810 | |
1811 | q->queue_ctx = ctx; | |
1812 | q->queue_hw_ctx = hctxs; | |
1813 | ||
24d2f903 | 1814 | q->mq_ops = set->ops; |
94eddfbe | 1815 | q->queue_flags |= QUEUE_FLAG_MQ_DEFAULT; |
320ae51f | 1816 | |
05f1dd53 JA |
1817 | if (!(set->flags & BLK_MQ_F_SG_MERGE)) |
1818 | q->queue_flags |= 1 << QUEUE_FLAG_NO_SG_MERGE; | |
1819 | ||
1be036e9 CH |
1820 | q->sg_reserved_size = INT_MAX; |
1821 | ||
6fca6a61 CH |
1822 | INIT_WORK(&q->requeue_work, blk_mq_requeue_work); |
1823 | INIT_LIST_HEAD(&q->requeue_list); | |
1824 | spin_lock_init(&q->requeue_lock); | |
1825 | ||
07068d5b JA |
1826 | if (q->nr_hw_queues > 1) |
1827 | blk_queue_make_request(q, blk_mq_make_request); | |
1828 | else | |
1829 | blk_queue_make_request(q, blk_sq_make_request); | |
1830 | ||
87ee7b11 | 1831 | blk_queue_rq_timed_out(q, blk_mq_rq_timed_out); |
24d2f903 CH |
1832 | if (set->timeout) |
1833 | blk_queue_rq_timeout(q, set->timeout); | |
320ae51f | 1834 | |
eba71768 JA |
1835 | /* |
1836 | * Do this after blk_queue_make_request() overrides it... | |
1837 | */ | |
1838 | q->nr_requests = set->queue_depth; | |
1839 | ||
24d2f903 CH |
1840 | if (set->ops->complete) |
1841 | blk_queue_softirq_done(q, set->ops->complete); | |
30a91cb4 | 1842 | |
320ae51f | 1843 | blk_mq_init_flush(q); |
24d2f903 | 1844 | blk_mq_init_cpu_queues(q, set->nr_hw_queues); |
320ae51f | 1845 | |
24d2f903 CH |
1846 | q->flush_rq = kzalloc(round_up(sizeof(struct request) + |
1847 | set->cmd_size, cache_line_size()), | |
1848 | GFP_KERNEL); | |
18741986 | 1849 | if (!q->flush_rq) |
320ae51f JA |
1850 | goto err_hw; |
1851 | ||
24d2f903 | 1852 | if (blk_mq_init_hw_queues(q, set)) |
18741986 CH |
1853 | goto err_flush_rq; |
1854 | ||
320ae51f JA |
1855 | mutex_lock(&all_q_mutex); |
1856 | list_add_tail(&q->all_q_node, &all_q_list); | |
1857 | mutex_unlock(&all_q_mutex); | |
1858 | ||
0d2602ca JA |
1859 | blk_mq_add_queue_tag_set(set, q); |
1860 | ||
484b4061 JA |
1861 | blk_mq_map_swqueue(q); |
1862 | ||
320ae51f | 1863 | return q; |
18741986 CH |
1864 | |
1865 | err_flush_rq: | |
1866 | kfree(q->flush_rq); | |
320ae51f | 1867 | err_hw: |
320ae51f JA |
1868 | blk_cleanup_queue(q); |
1869 | err_hctxs: | |
f14bbe77 | 1870 | kfree(map); |
24d2f903 | 1871 | for (i = 0; i < set->nr_hw_queues; i++) { |
320ae51f JA |
1872 | if (!hctxs[i]) |
1873 | break; | |
e4043dcf | 1874 | free_cpumask_var(hctxs[i]->cpumask); |
cdef54dd | 1875 | kfree(hctxs[i]); |
320ae51f | 1876 | } |
f14bbe77 | 1877 | err_map: |
320ae51f JA |
1878 | kfree(hctxs); |
1879 | err_percpu: | |
1880 | free_percpu(ctx); | |
1881 | return ERR_PTR(-ENOMEM); | |
1882 | } | |
1883 | EXPORT_SYMBOL(blk_mq_init_queue); | |
1884 | ||
1885 | void blk_mq_free_queue(struct request_queue *q) | |
1886 | { | |
624dbe47 | 1887 | struct blk_mq_tag_set *set = q->tag_set; |
320ae51f | 1888 | |
0d2602ca JA |
1889 | blk_mq_del_queue_tag_set(q); |
1890 | ||
624dbe47 ML |
1891 | blk_mq_exit_hw_queues(q, set, set->nr_hw_queues); |
1892 | blk_mq_free_hw_queues(q, set); | |
320ae51f | 1893 | |
3d2936f4 ML |
1894 | percpu_counter_destroy(&q->mq_usage_counter); |
1895 | ||
320ae51f JA |
1896 | free_percpu(q->queue_ctx); |
1897 | kfree(q->queue_hw_ctx); | |
1898 | kfree(q->mq_map); | |
1899 | ||
1900 | q->queue_ctx = NULL; | |
1901 | q->queue_hw_ctx = NULL; | |
1902 | q->mq_map = NULL; | |
1903 | ||
1904 | mutex_lock(&all_q_mutex); | |
1905 | list_del_init(&q->all_q_node); | |
1906 | mutex_unlock(&all_q_mutex); | |
1907 | } | |
320ae51f JA |
1908 | |
1909 | /* Basically redo blk_mq_init_queue with queue frozen */ | |
f618ef7c | 1910 | static void blk_mq_queue_reinit(struct request_queue *q) |
320ae51f JA |
1911 | { |
1912 | blk_mq_freeze_queue(q); | |
1913 | ||
67aec14c JA |
1914 | blk_mq_sysfs_unregister(q); |
1915 | ||
320ae51f JA |
1916 | blk_mq_update_queue_map(q->mq_map, q->nr_hw_queues); |
1917 | ||
1918 | /* | |
1919 | * redo blk_mq_init_cpu_queues and blk_mq_init_hw_queues. FIXME: maybe | |
1920 | * we should change hctx numa_node according to new topology (this | |
1921 | * involves free and re-allocate memory, worthy doing?) | |
1922 | */ | |
1923 | ||
1924 | blk_mq_map_swqueue(q); | |
1925 | ||
67aec14c JA |
1926 | blk_mq_sysfs_register(q); |
1927 | ||
320ae51f JA |
1928 | blk_mq_unfreeze_queue(q); |
1929 | } | |
1930 | ||
f618ef7c PG |
1931 | static int blk_mq_queue_reinit_notify(struct notifier_block *nb, |
1932 | unsigned long action, void *hcpu) | |
320ae51f JA |
1933 | { |
1934 | struct request_queue *q; | |
1935 | ||
1936 | /* | |
9fccfed8 JA |
1937 | * Before new mappings are established, hotadded cpu might already |
1938 | * start handling requests. This doesn't break anything as we map | |
1939 | * offline CPUs to first hardware queue. We will re-init the queue | |
1940 | * below to get optimal settings. | |
320ae51f JA |
1941 | */ |
1942 | if (action != CPU_DEAD && action != CPU_DEAD_FROZEN && | |
1943 | action != CPU_ONLINE && action != CPU_ONLINE_FROZEN) | |
1944 | return NOTIFY_OK; | |
1945 | ||
1946 | mutex_lock(&all_q_mutex); | |
1947 | list_for_each_entry(q, &all_q_list, all_q_node) | |
1948 | blk_mq_queue_reinit(q); | |
1949 | mutex_unlock(&all_q_mutex); | |
1950 | return NOTIFY_OK; | |
1951 | } | |
1952 | ||
a4391c64 JA |
1953 | /* |
1954 | * Alloc a tag set to be associated with one or more request queues. | |
1955 | * May fail with EINVAL for various error conditions. May adjust the | |
1956 | * requested depth down, if if it too large. In that case, the set | |
1957 | * value will be stored in set->queue_depth. | |
1958 | */ | |
24d2f903 CH |
1959 | int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set) |
1960 | { | |
1961 | int i; | |
1962 | ||
1963 | if (!set->nr_hw_queues) | |
1964 | return -EINVAL; | |
a4391c64 | 1965 | if (!set->queue_depth) |
24d2f903 CH |
1966 | return -EINVAL; |
1967 | if (set->queue_depth < set->reserved_tags + BLK_MQ_TAG_MIN) | |
1968 | return -EINVAL; | |
1969 | ||
cdef54dd | 1970 | if (!set->nr_hw_queues || !set->ops->queue_rq || !set->ops->map_queue) |
24d2f903 CH |
1971 | return -EINVAL; |
1972 | ||
a4391c64 JA |
1973 | if (set->queue_depth > BLK_MQ_MAX_DEPTH) { |
1974 | pr_info("blk-mq: reduced tag depth to %u\n", | |
1975 | BLK_MQ_MAX_DEPTH); | |
1976 | set->queue_depth = BLK_MQ_MAX_DEPTH; | |
1977 | } | |
24d2f903 | 1978 | |
48479005 ML |
1979 | set->tags = kmalloc_node(set->nr_hw_queues * |
1980 | sizeof(struct blk_mq_tags *), | |
24d2f903 CH |
1981 | GFP_KERNEL, set->numa_node); |
1982 | if (!set->tags) | |
1983 | goto out; | |
1984 | ||
1985 | for (i = 0; i < set->nr_hw_queues; i++) { | |
1986 | set->tags[i] = blk_mq_init_rq_map(set, i); | |
1987 | if (!set->tags[i]) | |
1988 | goto out_unwind; | |
1989 | } | |
1990 | ||
0d2602ca JA |
1991 | mutex_init(&set->tag_list_lock); |
1992 | INIT_LIST_HEAD(&set->tag_list); | |
1993 | ||
24d2f903 CH |
1994 | return 0; |
1995 | ||
1996 | out_unwind: | |
1997 | while (--i >= 0) | |
1998 | blk_mq_free_rq_map(set, set->tags[i], i); | |
1999 | out: | |
2000 | return -ENOMEM; | |
2001 | } | |
2002 | EXPORT_SYMBOL(blk_mq_alloc_tag_set); | |
2003 | ||
2004 | void blk_mq_free_tag_set(struct blk_mq_tag_set *set) | |
2005 | { | |
2006 | int i; | |
2007 | ||
484b4061 JA |
2008 | for (i = 0; i < set->nr_hw_queues; i++) { |
2009 | if (set->tags[i]) | |
2010 | blk_mq_free_rq_map(set, set->tags[i], i); | |
2011 | } | |
2012 | ||
981bd189 | 2013 | kfree(set->tags); |
24d2f903 CH |
2014 | } |
2015 | EXPORT_SYMBOL(blk_mq_free_tag_set); | |
2016 | ||
e3a2b3f9 JA |
2017 | int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr) |
2018 | { | |
2019 | struct blk_mq_tag_set *set = q->tag_set; | |
2020 | struct blk_mq_hw_ctx *hctx; | |
2021 | int i, ret; | |
2022 | ||
2023 | if (!set || nr > set->queue_depth) | |
2024 | return -EINVAL; | |
2025 | ||
2026 | ret = 0; | |
2027 | queue_for_each_hw_ctx(q, hctx, i) { | |
2028 | ret = blk_mq_tag_update_depth(hctx->tags, nr); | |
2029 | if (ret) | |
2030 | break; | |
2031 | } | |
2032 | ||
2033 | if (!ret) | |
2034 | q->nr_requests = nr; | |
2035 | ||
2036 | return ret; | |
2037 | } | |
2038 | ||
676141e4 JA |
2039 | void blk_mq_disable_hotplug(void) |
2040 | { | |
2041 | mutex_lock(&all_q_mutex); | |
2042 | } | |
2043 | ||
2044 | void blk_mq_enable_hotplug(void) | |
2045 | { | |
2046 | mutex_unlock(&all_q_mutex); | |
2047 | } | |
2048 | ||
320ae51f JA |
2049 | static int __init blk_mq_init(void) |
2050 | { | |
320ae51f JA |
2051 | blk_mq_cpu_init(); |
2052 | ||
2053 | /* Must be called after percpu_counter_hotcpu_callback() */ | |
2054 | hotcpu_notifier(blk_mq_queue_reinit_notify, -10); | |
2055 | ||
2056 | return 0; | |
2057 | } | |
2058 | subsys_initcall(blk_mq_init); |