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 | ||
43a5e4e2 ML |
112 | static void __blk_mq_drain_queue(struct request_queue *q) |
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; | |
123 | blk_mq_run_queues(q, false); | |
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 ML |
141 | if (drain) |
142 | __blk_mq_drain_queue(q); | |
143 | } | |
320ae51f | 144 | |
43a5e4e2 ML |
145 | void blk_mq_drain_queue(struct request_queue *q) |
146 | { | |
147 | __blk_mq_drain_queue(q); | |
320ae51f JA |
148 | } |
149 | ||
150 | static void blk_mq_unfreeze_queue(struct request_queue *q) | |
151 | { | |
152 | bool wake = false; | |
153 | ||
154 | spin_lock_irq(q->queue_lock); | |
155 | if (!--q->bypass_depth) { | |
156 | queue_flag_clear(QUEUE_FLAG_BYPASS, q); | |
157 | wake = true; | |
158 | } | |
159 | WARN_ON_ONCE(q->bypass_depth < 0); | |
160 | spin_unlock_irq(q->queue_lock); | |
161 | if (wake) | |
162 | wake_up_all(&q->mq_freeze_wq); | |
163 | } | |
164 | ||
165 | bool blk_mq_can_queue(struct blk_mq_hw_ctx *hctx) | |
166 | { | |
167 | return blk_mq_has_free_tags(hctx->tags); | |
168 | } | |
169 | EXPORT_SYMBOL(blk_mq_can_queue); | |
170 | ||
94eddfbe JA |
171 | static void blk_mq_rq_ctx_init(struct request_queue *q, struct blk_mq_ctx *ctx, |
172 | struct request *rq, unsigned int rw_flags) | |
320ae51f | 173 | { |
94eddfbe JA |
174 | if (blk_queue_io_stat(q)) |
175 | rw_flags |= REQ_IO_STAT; | |
176 | ||
af76e555 CH |
177 | INIT_LIST_HEAD(&rq->queuelist); |
178 | /* csd/requeue_work/fifo_time is initialized before use */ | |
179 | rq->q = q; | |
320ae51f | 180 | rq->mq_ctx = ctx; |
0d2602ca | 181 | rq->cmd_flags |= rw_flags; |
af76e555 CH |
182 | /* do not touch atomic flags, it needs atomic ops against the timer */ |
183 | rq->cpu = -1; | |
af76e555 CH |
184 | INIT_HLIST_NODE(&rq->hash); |
185 | RB_CLEAR_NODE(&rq->rb_node); | |
af76e555 CH |
186 | rq->rq_disk = NULL; |
187 | rq->part = NULL; | |
3ee32372 | 188 | rq->start_time = jiffies; |
af76e555 CH |
189 | #ifdef CONFIG_BLK_CGROUP |
190 | rq->rl = NULL; | |
0fec08b4 | 191 | set_start_time_ns(rq); |
af76e555 CH |
192 | rq->io_start_time_ns = 0; |
193 | #endif | |
194 | rq->nr_phys_segments = 0; | |
195 | #if defined(CONFIG_BLK_DEV_INTEGRITY) | |
196 | rq->nr_integrity_segments = 0; | |
197 | #endif | |
af76e555 CH |
198 | rq->special = NULL; |
199 | /* tag was already set */ | |
200 | rq->errors = 0; | |
af76e555 CH |
201 | |
202 | rq->extra_len = 0; | |
203 | rq->sense_len = 0; | |
204 | rq->resid_len = 0; | |
205 | rq->sense = NULL; | |
206 | ||
af76e555 | 207 | INIT_LIST_HEAD(&rq->timeout_list); |
f6be4fb4 JA |
208 | rq->timeout = 0; |
209 | ||
af76e555 CH |
210 | rq->end_io = NULL; |
211 | rq->end_io_data = NULL; | |
212 | rq->next_rq = NULL; | |
213 | ||
320ae51f JA |
214 | ctx->rq_dispatched[rw_is_sync(rw_flags)]++; |
215 | } | |
216 | ||
5dee8577 | 217 | static struct request * |
cb96a42c | 218 | __blk_mq_alloc_request(struct blk_mq_alloc_data *data, int rw) |
5dee8577 CH |
219 | { |
220 | struct request *rq; | |
221 | unsigned int tag; | |
222 | ||
cb96a42c | 223 | tag = blk_mq_get_tag(data); |
5dee8577 | 224 | if (tag != BLK_MQ_TAG_FAIL) { |
cb96a42c | 225 | rq = data->hctx->tags->rqs[tag]; |
5dee8577 CH |
226 | |
227 | rq->cmd_flags = 0; | |
cb96a42c | 228 | if (blk_mq_tag_busy(data->hctx)) { |
5dee8577 | 229 | rq->cmd_flags = REQ_MQ_INFLIGHT; |
cb96a42c | 230 | atomic_inc(&data->hctx->nr_active); |
5dee8577 CH |
231 | } |
232 | ||
233 | rq->tag = tag; | |
cb96a42c | 234 | blk_mq_rq_ctx_init(data->q, data->ctx, rq, rw); |
5dee8577 CH |
235 | return rq; |
236 | } | |
237 | ||
238 | return NULL; | |
239 | } | |
240 | ||
4ce01dd1 CH |
241 | struct request *blk_mq_alloc_request(struct request_queue *q, int rw, gfp_t gfp, |
242 | bool reserved) | |
320ae51f | 243 | { |
d852564f CH |
244 | struct blk_mq_ctx *ctx; |
245 | struct blk_mq_hw_ctx *hctx; | |
320ae51f | 246 | struct request *rq; |
cb96a42c | 247 | struct blk_mq_alloc_data alloc_data; |
320ae51f JA |
248 | |
249 | if (blk_mq_queue_enter(q)) | |
250 | return NULL; | |
251 | ||
d852564f CH |
252 | ctx = blk_mq_get_ctx(q); |
253 | hctx = q->mq_ops->map_queue(q, ctx->cpu); | |
cb96a42c ML |
254 | blk_mq_set_alloc_data(&alloc_data, q, gfp & ~__GFP_WAIT, |
255 | reserved, ctx, hctx); | |
d852564f | 256 | |
cb96a42c | 257 | rq = __blk_mq_alloc_request(&alloc_data, rw); |
d852564f CH |
258 | if (!rq && (gfp & __GFP_WAIT)) { |
259 | __blk_mq_run_hw_queue(hctx); | |
260 | blk_mq_put_ctx(ctx); | |
261 | ||
262 | ctx = blk_mq_get_ctx(q); | |
263 | hctx = q->mq_ops->map_queue(q, ctx->cpu); | |
cb96a42c ML |
264 | blk_mq_set_alloc_data(&alloc_data, q, gfp, reserved, ctx, |
265 | hctx); | |
266 | rq = __blk_mq_alloc_request(&alloc_data, rw); | |
267 | ctx = alloc_data.ctx; | |
d852564f CH |
268 | } |
269 | blk_mq_put_ctx(ctx); | |
320ae51f JA |
270 | return rq; |
271 | } | |
4bb659b1 | 272 | EXPORT_SYMBOL(blk_mq_alloc_request); |
320ae51f | 273 | |
320ae51f JA |
274 | static void __blk_mq_free_request(struct blk_mq_hw_ctx *hctx, |
275 | struct blk_mq_ctx *ctx, struct request *rq) | |
276 | { | |
277 | const int tag = rq->tag; | |
278 | struct request_queue *q = rq->q; | |
279 | ||
0d2602ca JA |
280 | if (rq->cmd_flags & REQ_MQ_INFLIGHT) |
281 | atomic_dec(&hctx->nr_active); | |
282 | ||
af76e555 | 283 | clear_bit(REQ_ATOM_STARTED, &rq->atomic_flags); |
0d2602ca | 284 | blk_mq_put_tag(hctx, tag, &ctx->last_tag); |
320ae51f JA |
285 | blk_mq_queue_exit(q); |
286 | } | |
287 | ||
288 | void blk_mq_free_request(struct request *rq) | |
289 | { | |
290 | struct blk_mq_ctx *ctx = rq->mq_ctx; | |
291 | struct blk_mq_hw_ctx *hctx; | |
292 | struct request_queue *q = rq->q; | |
293 | ||
294 | ctx->rq_completed[rq_is_sync(rq)]++; | |
295 | ||
296 | hctx = q->mq_ops->map_queue(q, ctx->cpu); | |
297 | __blk_mq_free_request(hctx, ctx, rq); | |
298 | } | |
299 | ||
8727af4b CH |
300 | /* |
301 | * Clone all relevant state from a request that has been put on hold in | |
302 | * the flush state machine into the preallocated flush request that hangs | |
303 | * off the request queue. | |
304 | * | |
305 | * For a driver the flush request should be invisible, that's why we are | |
306 | * impersonating the original request here. | |
307 | */ | |
308 | void blk_mq_clone_flush_request(struct request *flush_rq, | |
309 | struct request *orig_rq) | |
310 | { | |
311 | struct blk_mq_hw_ctx *hctx = | |
312 | orig_rq->q->mq_ops->map_queue(orig_rq->q, orig_rq->mq_ctx->cpu); | |
313 | ||
314 | flush_rq->mq_ctx = orig_rq->mq_ctx; | |
315 | flush_rq->tag = orig_rq->tag; | |
316 | memcpy(blk_mq_rq_to_pdu(flush_rq), blk_mq_rq_to_pdu(orig_rq), | |
317 | hctx->cmd_size); | |
318 | } | |
319 | ||
63151a44 | 320 | inline void __blk_mq_end_io(struct request *rq, int error) |
320ae51f | 321 | { |
0d11e6ac ML |
322 | blk_account_io_done(rq); |
323 | ||
91b63639 | 324 | if (rq->end_io) { |
320ae51f | 325 | rq->end_io(rq, error); |
91b63639 CH |
326 | } else { |
327 | if (unlikely(blk_bidi_rq(rq))) | |
328 | blk_mq_free_request(rq->next_rq); | |
320ae51f | 329 | blk_mq_free_request(rq); |
91b63639 | 330 | } |
320ae51f | 331 | } |
63151a44 CH |
332 | EXPORT_SYMBOL(__blk_mq_end_io); |
333 | ||
334 | void blk_mq_end_io(struct request *rq, int error) | |
335 | { | |
336 | if (blk_update_request(rq, error, blk_rq_bytes(rq))) | |
337 | BUG(); | |
338 | __blk_mq_end_io(rq, error); | |
339 | } | |
340 | EXPORT_SYMBOL(blk_mq_end_io); | |
320ae51f | 341 | |
30a91cb4 | 342 | static void __blk_mq_complete_request_remote(void *data) |
320ae51f | 343 | { |
3d6efbf6 | 344 | struct request *rq = data; |
320ae51f | 345 | |
30a91cb4 | 346 | rq->q->softirq_done_fn(rq); |
320ae51f | 347 | } |
320ae51f | 348 | |
ed851860 | 349 | static void blk_mq_ipi_complete_request(struct request *rq) |
320ae51f JA |
350 | { |
351 | struct blk_mq_ctx *ctx = rq->mq_ctx; | |
38535201 | 352 | bool shared = false; |
320ae51f JA |
353 | int cpu; |
354 | ||
38535201 | 355 | if (!test_bit(QUEUE_FLAG_SAME_COMP, &rq->q->queue_flags)) { |
30a91cb4 CH |
356 | rq->q->softirq_done_fn(rq); |
357 | return; | |
358 | } | |
320ae51f JA |
359 | |
360 | cpu = get_cpu(); | |
38535201 CH |
361 | if (!test_bit(QUEUE_FLAG_SAME_FORCE, &rq->q->queue_flags)) |
362 | shared = cpus_share_cache(cpu, ctx->cpu); | |
363 | ||
364 | if (cpu != ctx->cpu && !shared && cpu_online(ctx->cpu)) { | |
30a91cb4 | 365 | rq->csd.func = __blk_mq_complete_request_remote; |
3d6efbf6 CH |
366 | rq->csd.info = rq; |
367 | rq->csd.flags = 0; | |
c46fff2a | 368 | smp_call_function_single_async(ctx->cpu, &rq->csd); |
3d6efbf6 | 369 | } else { |
30a91cb4 | 370 | rq->q->softirq_done_fn(rq); |
3d6efbf6 | 371 | } |
320ae51f JA |
372 | put_cpu(); |
373 | } | |
30a91cb4 | 374 | |
ed851860 JA |
375 | void __blk_mq_complete_request(struct request *rq) |
376 | { | |
377 | struct request_queue *q = rq->q; | |
378 | ||
379 | if (!q->softirq_done_fn) | |
380 | blk_mq_end_io(rq, rq->errors); | |
381 | else | |
382 | blk_mq_ipi_complete_request(rq); | |
383 | } | |
384 | ||
30a91cb4 CH |
385 | /** |
386 | * blk_mq_complete_request - end I/O on a request | |
387 | * @rq: the request being processed | |
388 | * | |
389 | * Description: | |
390 | * Ends all I/O on a request. It does not handle partial completions. | |
391 | * The actual completion happens out-of-order, through a IPI handler. | |
392 | **/ | |
393 | void blk_mq_complete_request(struct request *rq) | |
394 | { | |
95f09684 JA |
395 | struct request_queue *q = rq->q; |
396 | ||
397 | if (unlikely(blk_should_fake_timeout(q))) | |
30a91cb4 | 398 | return; |
ed851860 JA |
399 | if (!blk_mark_rq_complete(rq)) |
400 | __blk_mq_complete_request(rq); | |
30a91cb4 CH |
401 | } |
402 | EXPORT_SYMBOL(blk_mq_complete_request); | |
320ae51f | 403 | |
49f5baa5 | 404 | static void blk_mq_start_request(struct request *rq, bool last) |
320ae51f JA |
405 | { |
406 | struct request_queue *q = rq->q; | |
407 | ||
408 | trace_block_rq_issue(q, rq); | |
409 | ||
742ee69b | 410 | rq->resid_len = blk_rq_bytes(rq); |
91b63639 CH |
411 | if (unlikely(blk_bidi_rq(rq))) |
412 | rq->next_rq->resid_len = blk_rq_bytes(rq->next_rq); | |
742ee69b | 413 | |
2b8393b4 | 414 | blk_add_timer(rq); |
87ee7b11 JA |
415 | |
416 | /* | |
417 | * Mark us as started and clear complete. Complete might have been | |
418 | * set if requeue raced with timeout, which then marked it as | |
419 | * complete. So be sure to clear complete again when we start | |
420 | * the request, otherwise we'll ignore the completion event. | |
421 | */ | |
4b570521 JA |
422 | if (!test_bit(REQ_ATOM_STARTED, &rq->atomic_flags)) |
423 | set_bit(REQ_ATOM_STARTED, &rq->atomic_flags); | |
424 | if (test_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags)) | |
425 | clear_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags); | |
49f5baa5 CH |
426 | |
427 | if (q->dma_drain_size && blk_rq_bytes(rq)) { | |
428 | /* | |
429 | * Make sure space for the drain appears. We know we can do | |
430 | * this because max_hw_segments has been adjusted to be one | |
431 | * fewer than the device can handle. | |
432 | */ | |
433 | rq->nr_phys_segments++; | |
434 | } | |
435 | ||
436 | /* | |
437 | * Flag the last request in the series so that drivers know when IO | |
438 | * should be kicked off, if they don't do it on a per-request basis. | |
439 | * | |
440 | * Note: the flag isn't the only condition drivers should do kick off. | |
441 | * If drive is busy, the last request might not have the bit set. | |
442 | */ | |
443 | if (last) | |
444 | rq->cmd_flags |= REQ_END; | |
320ae51f JA |
445 | } |
446 | ||
ed0791b2 | 447 | static void __blk_mq_requeue_request(struct request *rq) |
320ae51f JA |
448 | { |
449 | struct request_queue *q = rq->q; | |
450 | ||
451 | trace_block_rq_requeue(q, rq); | |
452 | clear_bit(REQ_ATOM_STARTED, &rq->atomic_flags); | |
49f5baa5 CH |
453 | |
454 | rq->cmd_flags &= ~REQ_END; | |
455 | ||
456 | if (q->dma_drain_size && blk_rq_bytes(rq)) | |
457 | rq->nr_phys_segments--; | |
320ae51f JA |
458 | } |
459 | ||
ed0791b2 CH |
460 | void blk_mq_requeue_request(struct request *rq) |
461 | { | |
ed0791b2 CH |
462 | __blk_mq_requeue_request(rq); |
463 | blk_clear_rq_complete(rq); | |
464 | ||
ed0791b2 | 465 | BUG_ON(blk_queued_rq(rq)); |
6fca6a61 | 466 | blk_mq_add_to_requeue_list(rq, true); |
ed0791b2 CH |
467 | } |
468 | EXPORT_SYMBOL(blk_mq_requeue_request); | |
469 | ||
6fca6a61 CH |
470 | static void blk_mq_requeue_work(struct work_struct *work) |
471 | { | |
472 | struct request_queue *q = | |
473 | container_of(work, struct request_queue, requeue_work); | |
474 | LIST_HEAD(rq_list); | |
475 | struct request *rq, *next; | |
476 | unsigned long flags; | |
477 | ||
478 | spin_lock_irqsave(&q->requeue_lock, flags); | |
479 | list_splice_init(&q->requeue_list, &rq_list); | |
480 | spin_unlock_irqrestore(&q->requeue_lock, flags); | |
481 | ||
482 | list_for_each_entry_safe(rq, next, &rq_list, queuelist) { | |
483 | if (!(rq->cmd_flags & REQ_SOFTBARRIER)) | |
484 | continue; | |
485 | ||
486 | rq->cmd_flags &= ~REQ_SOFTBARRIER; | |
487 | list_del_init(&rq->queuelist); | |
488 | blk_mq_insert_request(rq, true, false, false); | |
489 | } | |
490 | ||
491 | while (!list_empty(&rq_list)) { | |
492 | rq = list_entry(rq_list.next, struct request, queuelist); | |
493 | list_del_init(&rq->queuelist); | |
494 | blk_mq_insert_request(rq, false, false, false); | |
495 | } | |
496 | ||
497 | blk_mq_run_queues(q, false); | |
498 | } | |
499 | ||
500 | void blk_mq_add_to_requeue_list(struct request *rq, bool at_head) | |
501 | { | |
502 | struct request_queue *q = rq->q; | |
503 | unsigned long flags; | |
504 | ||
505 | /* | |
506 | * We abuse this flag that is otherwise used by the I/O scheduler to | |
507 | * request head insertation from the workqueue. | |
508 | */ | |
509 | BUG_ON(rq->cmd_flags & REQ_SOFTBARRIER); | |
510 | ||
511 | spin_lock_irqsave(&q->requeue_lock, flags); | |
512 | if (at_head) { | |
513 | rq->cmd_flags |= REQ_SOFTBARRIER; | |
514 | list_add(&rq->queuelist, &q->requeue_list); | |
515 | } else { | |
516 | list_add_tail(&rq->queuelist, &q->requeue_list); | |
517 | } | |
518 | spin_unlock_irqrestore(&q->requeue_lock, flags); | |
519 | } | |
520 | EXPORT_SYMBOL(blk_mq_add_to_requeue_list); | |
521 | ||
522 | void blk_mq_kick_requeue_list(struct request_queue *q) | |
523 | { | |
524 | kblockd_schedule_work(&q->requeue_work); | |
525 | } | |
526 | EXPORT_SYMBOL(blk_mq_kick_requeue_list); | |
527 | ||
0e62f51f | 528 | static inline bool is_flush_request(struct request *rq, unsigned int tag) |
24d2f903 | 529 | { |
0e62f51f JA |
530 | return ((rq->cmd_flags & REQ_FLUSH_SEQ) && |
531 | rq->q->flush_rq->tag == tag); | |
532 | } | |
533 | ||
534 | struct request *blk_mq_tag_to_rq(struct blk_mq_tags *tags, unsigned int tag) | |
535 | { | |
536 | struct request *rq = tags->rqs[tag]; | |
22302375 | 537 | |
0e62f51f JA |
538 | if (!is_flush_request(rq, tag)) |
539 | return rq; | |
22302375 | 540 | |
0e62f51f | 541 | return rq->q->flush_rq; |
24d2f903 CH |
542 | } |
543 | EXPORT_SYMBOL(blk_mq_tag_to_rq); | |
544 | ||
320ae51f JA |
545 | struct blk_mq_timeout_data { |
546 | struct blk_mq_hw_ctx *hctx; | |
547 | unsigned long *next; | |
548 | unsigned int *next_set; | |
549 | }; | |
550 | ||
551 | static void blk_mq_timeout_check(void *__data, unsigned long *free_tags) | |
552 | { | |
553 | struct blk_mq_timeout_data *data = __data; | |
554 | struct blk_mq_hw_ctx *hctx = data->hctx; | |
555 | unsigned int tag; | |
556 | ||
557 | /* It may not be in flight yet (this is where | |
558 | * the REQ_ATOMIC_STARTED flag comes in). The requests are | |
559 | * statically allocated, so we know it's always safe to access the | |
560 | * memory associated with a bit offset into ->rqs[]. | |
561 | */ | |
562 | tag = 0; | |
563 | do { | |
564 | struct request *rq; | |
565 | ||
24d2f903 CH |
566 | tag = find_next_zero_bit(free_tags, hctx->tags->nr_tags, tag); |
567 | if (tag >= hctx->tags->nr_tags) | |
320ae51f JA |
568 | break; |
569 | ||
0e62f51f | 570 | rq = blk_mq_tag_to_rq(hctx->tags, tag++); |
24d2f903 CH |
571 | if (rq->q != hctx->queue) |
572 | continue; | |
320ae51f JA |
573 | if (!test_bit(REQ_ATOM_STARTED, &rq->atomic_flags)) |
574 | continue; | |
575 | ||
576 | blk_rq_check_expired(rq, data->next, data->next_set); | |
577 | } while (1); | |
578 | } | |
579 | ||
580 | static void blk_mq_hw_ctx_check_timeout(struct blk_mq_hw_ctx *hctx, | |
581 | unsigned long *next, | |
582 | unsigned int *next_set) | |
583 | { | |
584 | struct blk_mq_timeout_data data = { | |
585 | .hctx = hctx, | |
586 | .next = next, | |
587 | .next_set = next_set, | |
588 | }; | |
589 | ||
590 | /* | |
591 | * Ask the tagging code to iterate busy requests, so we can | |
592 | * check them for timeout. | |
593 | */ | |
594 | blk_mq_tag_busy_iter(hctx->tags, blk_mq_timeout_check, &data); | |
595 | } | |
596 | ||
87ee7b11 JA |
597 | static enum blk_eh_timer_return blk_mq_rq_timed_out(struct request *rq) |
598 | { | |
599 | struct request_queue *q = rq->q; | |
600 | ||
601 | /* | |
602 | * We know that complete is set at this point. If STARTED isn't set | |
603 | * anymore, then the request isn't active and the "timeout" should | |
604 | * just be ignored. This can happen due to the bitflag ordering. | |
605 | * Timeout first checks if STARTED is set, and if it is, assumes | |
606 | * the request is active. But if we race with completion, then | |
607 | * we both flags will get cleared. So check here again, and ignore | |
608 | * a timeout event with a request that isn't active. | |
609 | */ | |
610 | if (!test_bit(REQ_ATOM_STARTED, &rq->atomic_flags)) | |
611 | return BLK_EH_NOT_HANDLED; | |
612 | ||
613 | if (!q->mq_ops->timeout) | |
614 | return BLK_EH_RESET_TIMER; | |
615 | ||
616 | return q->mq_ops->timeout(rq); | |
617 | } | |
618 | ||
320ae51f JA |
619 | static void blk_mq_rq_timer(unsigned long data) |
620 | { | |
621 | struct request_queue *q = (struct request_queue *) data; | |
622 | struct blk_mq_hw_ctx *hctx; | |
623 | unsigned long next = 0; | |
624 | int i, next_set = 0; | |
625 | ||
484b4061 JA |
626 | queue_for_each_hw_ctx(q, hctx, i) { |
627 | /* | |
628 | * If not software queues are currently mapped to this | |
629 | * hardware queue, there's nothing to check | |
630 | */ | |
631 | if (!hctx->nr_ctx || !hctx->tags) | |
632 | continue; | |
633 | ||
320ae51f | 634 | blk_mq_hw_ctx_check_timeout(hctx, &next, &next_set); |
484b4061 | 635 | } |
320ae51f | 636 | |
0d2602ca JA |
637 | if (next_set) { |
638 | next = blk_rq_timeout(round_jiffies_up(next)); | |
639 | mod_timer(&q->timeout, next); | |
640 | } else { | |
641 | queue_for_each_hw_ctx(q, hctx, i) | |
642 | blk_mq_tag_idle(hctx); | |
643 | } | |
320ae51f JA |
644 | } |
645 | ||
646 | /* | |
647 | * Reverse check our software queue for entries that we could potentially | |
648 | * merge with. Currently includes a hand-wavy stop count of 8, to not spend | |
649 | * too much time checking for merges. | |
650 | */ | |
651 | static bool blk_mq_attempt_merge(struct request_queue *q, | |
652 | struct blk_mq_ctx *ctx, struct bio *bio) | |
653 | { | |
654 | struct request *rq; | |
655 | int checked = 8; | |
656 | ||
657 | list_for_each_entry_reverse(rq, &ctx->rq_list, queuelist) { | |
658 | int el_ret; | |
659 | ||
660 | if (!checked--) | |
661 | break; | |
662 | ||
663 | if (!blk_rq_merge_ok(rq, bio)) | |
664 | continue; | |
665 | ||
666 | el_ret = blk_try_merge(rq, bio); | |
667 | if (el_ret == ELEVATOR_BACK_MERGE) { | |
668 | if (bio_attempt_back_merge(q, rq, bio)) { | |
669 | ctx->rq_merged++; | |
670 | return true; | |
671 | } | |
672 | break; | |
673 | } else if (el_ret == ELEVATOR_FRONT_MERGE) { | |
674 | if (bio_attempt_front_merge(q, rq, bio)) { | |
675 | ctx->rq_merged++; | |
676 | return true; | |
677 | } | |
678 | break; | |
679 | } | |
680 | } | |
681 | ||
682 | return false; | |
683 | } | |
684 | ||
1429d7c9 JA |
685 | /* |
686 | * Process software queues that have been marked busy, splicing them | |
687 | * to the for-dispatch | |
688 | */ | |
689 | static void flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, struct list_head *list) | |
690 | { | |
691 | struct blk_mq_ctx *ctx; | |
692 | int i; | |
693 | ||
694 | for (i = 0; i < hctx->ctx_map.map_size; i++) { | |
695 | struct blk_align_bitmap *bm = &hctx->ctx_map.map[i]; | |
696 | unsigned int off, bit; | |
697 | ||
698 | if (!bm->word) | |
699 | continue; | |
700 | ||
701 | bit = 0; | |
702 | off = i * hctx->ctx_map.bits_per_word; | |
703 | do { | |
704 | bit = find_next_bit(&bm->word, bm->depth, bit); | |
705 | if (bit >= bm->depth) | |
706 | break; | |
707 | ||
708 | ctx = hctx->ctxs[bit + off]; | |
709 | clear_bit(bit, &bm->word); | |
710 | spin_lock(&ctx->lock); | |
711 | list_splice_tail_init(&ctx->rq_list, list); | |
712 | spin_unlock(&ctx->lock); | |
713 | ||
714 | bit++; | |
715 | } while (1); | |
716 | } | |
717 | } | |
718 | ||
320ae51f JA |
719 | /* |
720 | * Run this hardware queue, pulling any software queues mapped to it in. | |
721 | * Note that this function currently has various problems around ordering | |
722 | * of IO. In particular, we'd like FIFO behaviour on handling existing | |
723 | * items on the hctx->dispatch list. Ignore that for now. | |
724 | */ | |
725 | static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx) | |
726 | { | |
727 | struct request_queue *q = hctx->queue; | |
320ae51f JA |
728 | struct request *rq; |
729 | LIST_HEAD(rq_list); | |
1429d7c9 | 730 | int queued; |
320ae51f | 731 | |
fd1270d5 | 732 | WARN_ON(!cpumask_test_cpu(raw_smp_processor_id(), hctx->cpumask)); |
e4043dcf | 733 | |
5d12f905 | 734 | if (unlikely(test_bit(BLK_MQ_S_STOPPED, &hctx->state))) |
320ae51f JA |
735 | return; |
736 | ||
737 | hctx->run++; | |
738 | ||
739 | /* | |
740 | * Touch any software queue that has pending entries. | |
741 | */ | |
1429d7c9 | 742 | flush_busy_ctxs(hctx, &rq_list); |
320ae51f JA |
743 | |
744 | /* | |
745 | * If we have previous entries on our dispatch list, grab them | |
746 | * and stuff them at the front for more fair dispatch. | |
747 | */ | |
748 | if (!list_empty_careful(&hctx->dispatch)) { | |
749 | spin_lock(&hctx->lock); | |
750 | if (!list_empty(&hctx->dispatch)) | |
751 | list_splice_init(&hctx->dispatch, &rq_list); | |
752 | spin_unlock(&hctx->lock); | |
753 | } | |
754 | ||
320ae51f JA |
755 | /* |
756 | * Now process all the entries, sending them to the driver. | |
757 | */ | |
1429d7c9 | 758 | queued = 0; |
320ae51f JA |
759 | while (!list_empty(&rq_list)) { |
760 | int ret; | |
761 | ||
762 | rq = list_first_entry(&rq_list, struct request, queuelist); | |
763 | list_del_init(&rq->queuelist); | |
320ae51f | 764 | |
49f5baa5 | 765 | blk_mq_start_request(rq, list_empty(&rq_list)); |
320ae51f JA |
766 | |
767 | ret = q->mq_ops->queue_rq(hctx, rq); | |
768 | switch (ret) { | |
769 | case BLK_MQ_RQ_QUEUE_OK: | |
770 | queued++; | |
771 | continue; | |
772 | case BLK_MQ_RQ_QUEUE_BUSY: | |
320ae51f | 773 | list_add(&rq->queuelist, &rq_list); |
ed0791b2 | 774 | __blk_mq_requeue_request(rq); |
320ae51f JA |
775 | break; |
776 | default: | |
777 | pr_err("blk-mq: bad return on queue: %d\n", ret); | |
320ae51f | 778 | case BLK_MQ_RQ_QUEUE_ERROR: |
1e93b8c2 | 779 | rq->errors = -EIO; |
320ae51f JA |
780 | blk_mq_end_io(rq, rq->errors); |
781 | break; | |
782 | } | |
783 | ||
784 | if (ret == BLK_MQ_RQ_QUEUE_BUSY) | |
785 | break; | |
786 | } | |
787 | ||
788 | if (!queued) | |
789 | hctx->dispatched[0]++; | |
790 | else if (queued < (1 << (BLK_MQ_MAX_DISPATCH_ORDER - 1))) | |
791 | hctx->dispatched[ilog2(queued) + 1]++; | |
792 | ||
793 | /* | |
794 | * Any items that need requeuing? Stuff them into hctx->dispatch, | |
795 | * that is where we will continue on next queue run. | |
796 | */ | |
797 | if (!list_empty(&rq_list)) { | |
798 | spin_lock(&hctx->lock); | |
799 | list_splice(&rq_list, &hctx->dispatch); | |
800 | spin_unlock(&hctx->lock); | |
801 | } | |
802 | } | |
803 | ||
506e931f JA |
804 | /* |
805 | * It'd be great if the workqueue API had a way to pass | |
806 | * in a mask and had some smarts for more clever placement. | |
807 | * For now we just round-robin here, switching for every | |
808 | * BLK_MQ_CPU_WORK_BATCH queued items. | |
809 | */ | |
810 | static int blk_mq_hctx_next_cpu(struct blk_mq_hw_ctx *hctx) | |
811 | { | |
812 | int cpu = hctx->next_cpu; | |
813 | ||
814 | if (--hctx->next_cpu_batch <= 0) { | |
815 | int next_cpu; | |
816 | ||
817 | next_cpu = cpumask_next(hctx->next_cpu, hctx->cpumask); | |
818 | if (next_cpu >= nr_cpu_ids) | |
819 | next_cpu = cpumask_first(hctx->cpumask); | |
820 | ||
821 | hctx->next_cpu = next_cpu; | |
822 | hctx->next_cpu_batch = BLK_MQ_CPU_WORK_BATCH; | |
823 | } | |
824 | ||
825 | return cpu; | |
826 | } | |
827 | ||
320ae51f JA |
828 | void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async) |
829 | { | |
5d12f905 | 830 | if (unlikely(test_bit(BLK_MQ_S_STOPPED, &hctx->state))) |
320ae51f JA |
831 | return; |
832 | ||
e4043dcf | 833 | if (!async && cpumask_test_cpu(smp_processor_id(), hctx->cpumask)) |
320ae51f | 834 | __blk_mq_run_hw_queue(hctx); |
e4043dcf | 835 | else if (hctx->queue->nr_hw_queues == 1) |
70f4db63 | 836 | kblockd_schedule_delayed_work(&hctx->run_work, 0); |
e4043dcf JA |
837 | else { |
838 | unsigned int cpu; | |
839 | ||
506e931f | 840 | cpu = blk_mq_hctx_next_cpu(hctx); |
70f4db63 | 841 | kblockd_schedule_delayed_work_on(cpu, &hctx->run_work, 0); |
e4043dcf | 842 | } |
320ae51f JA |
843 | } |
844 | ||
845 | void blk_mq_run_queues(struct request_queue *q, bool async) | |
846 | { | |
847 | struct blk_mq_hw_ctx *hctx; | |
848 | int i; | |
849 | ||
850 | queue_for_each_hw_ctx(q, hctx, i) { | |
851 | if ((!blk_mq_hctx_has_pending(hctx) && | |
852 | list_empty_careful(&hctx->dispatch)) || | |
5d12f905 | 853 | test_bit(BLK_MQ_S_STOPPED, &hctx->state)) |
320ae51f JA |
854 | continue; |
855 | ||
e4043dcf | 856 | preempt_disable(); |
320ae51f | 857 | blk_mq_run_hw_queue(hctx, async); |
e4043dcf | 858 | preempt_enable(); |
320ae51f JA |
859 | } |
860 | } | |
861 | EXPORT_SYMBOL(blk_mq_run_queues); | |
862 | ||
863 | void blk_mq_stop_hw_queue(struct blk_mq_hw_ctx *hctx) | |
864 | { | |
70f4db63 CH |
865 | cancel_delayed_work(&hctx->run_work); |
866 | cancel_delayed_work(&hctx->delay_work); | |
320ae51f JA |
867 | set_bit(BLK_MQ_S_STOPPED, &hctx->state); |
868 | } | |
869 | EXPORT_SYMBOL(blk_mq_stop_hw_queue); | |
870 | ||
280d45f6 CH |
871 | void blk_mq_stop_hw_queues(struct request_queue *q) |
872 | { | |
873 | struct blk_mq_hw_ctx *hctx; | |
874 | int i; | |
875 | ||
876 | queue_for_each_hw_ctx(q, hctx, i) | |
877 | blk_mq_stop_hw_queue(hctx); | |
878 | } | |
879 | EXPORT_SYMBOL(blk_mq_stop_hw_queues); | |
880 | ||
320ae51f JA |
881 | void blk_mq_start_hw_queue(struct blk_mq_hw_ctx *hctx) |
882 | { | |
883 | clear_bit(BLK_MQ_S_STOPPED, &hctx->state); | |
e4043dcf JA |
884 | |
885 | preempt_disable(); | |
320ae51f | 886 | __blk_mq_run_hw_queue(hctx); |
e4043dcf | 887 | preempt_enable(); |
320ae51f JA |
888 | } |
889 | EXPORT_SYMBOL(blk_mq_start_hw_queue); | |
890 | ||
2f268556 CH |
891 | void blk_mq_start_hw_queues(struct request_queue *q) |
892 | { | |
893 | struct blk_mq_hw_ctx *hctx; | |
894 | int i; | |
895 | ||
896 | queue_for_each_hw_ctx(q, hctx, i) | |
897 | blk_mq_start_hw_queue(hctx); | |
898 | } | |
899 | EXPORT_SYMBOL(blk_mq_start_hw_queues); | |
900 | ||
901 | ||
1b4a3258 | 902 | void blk_mq_start_stopped_hw_queues(struct request_queue *q, bool async) |
320ae51f JA |
903 | { |
904 | struct blk_mq_hw_ctx *hctx; | |
905 | int i; | |
906 | ||
907 | queue_for_each_hw_ctx(q, hctx, i) { | |
908 | if (!test_bit(BLK_MQ_S_STOPPED, &hctx->state)) | |
909 | continue; | |
910 | ||
911 | clear_bit(BLK_MQ_S_STOPPED, &hctx->state); | |
e4043dcf | 912 | preempt_disable(); |
1b4a3258 | 913 | blk_mq_run_hw_queue(hctx, async); |
e4043dcf | 914 | preempt_enable(); |
320ae51f JA |
915 | } |
916 | } | |
917 | EXPORT_SYMBOL(blk_mq_start_stopped_hw_queues); | |
918 | ||
70f4db63 | 919 | static void blk_mq_run_work_fn(struct work_struct *work) |
320ae51f JA |
920 | { |
921 | struct blk_mq_hw_ctx *hctx; | |
922 | ||
70f4db63 | 923 | hctx = container_of(work, struct blk_mq_hw_ctx, run_work.work); |
e4043dcf | 924 | |
320ae51f JA |
925 | __blk_mq_run_hw_queue(hctx); |
926 | } | |
927 | ||
70f4db63 CH |
928 | static void blk_mq_delay_work_fn(struct work_struct *work) |
929 | { | |
930 | struct blk_mq_hw_ctx *hctx; | |
931 | ||
932 | hctx = container_of(work, struct blk_mq_hw_ctx, delay_work.work); | |
933 | ||
934 | if (test_and_clear_bit(BLK_MQ_S_STOPPED, &hctx->state)) | |
935 | __blk_mq_run_hw_queue(hctx); | |
936 | } | |
937 | ||
938 | void blk_mq_delay_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs) | |
939 | { | |
940 | unsigned long tmo = msecs_to_jiffies(msecs); | |
941 | ||
942 | if (hctx->queue->nr_hw_queues == 1) | |
943 | kblockd_schedule_delayed_work(&hctx->delay_work, tmo); | |
944 | else { | |
945 | unsigned int cpu; | |
946 | ||
506e931f | 947 | cpu = blk_mq_hctx_next_cpu(hctx); |
70f4db63 CH |
948 | kblockd_schedule_delayed_work_on(cpu, &hctx->delay_work, tmo); |
949 | } | |
950 | } | |
951 | EXPORT_SYMBOL(blk_mq_delay_queue); | |
952 | ||
320ae51f | 953 | static void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, |
72a0a36e | 954 | struct request *rq, bool at_head) |
320ae51f JA |
955 | { |
956 | struct blk_mq_ctx *ctx = rq->mq_ctx; | |
957 | ||
01b983c9 JA |
958 | trace_block_rq_insert(hctx->queue, rq); |
959 | ||
72a0a36e CH |
960 | if (at_head) |
961 | list_add(&rq->queuelist, &ctx->rq_list); | |
962 | else | |
963 | list_add_tail(&rq->queuelist, &ctx->rq_list); | |
4bb659b1 | 964 | |
320ae51f | 965 | blk_mq_hctx_mark_pending(hctx, ctx); |
320ae51f JA |
966 | } |
967 | ||
eeabc850 CH |
968 | void blk_mq_insert_request(struct request *rq, bool at_head, bool run_queue, |
969 | bool async) | |
320ae51f | 970 | { |
eeabc850 | 971 | struct request_queue *q = rq->q; |
320ae51f | 972 | struct blk_mq_hw_ctx *hctx; |
eeabc850 CH |
973 | struct blk_mq_ctx *ctx = rq->mq_ctx, *current_ctx; |
974 | ||
975 | current_ctx = blk_mq_get_ctx(q); | |
976 | if (!cpu_online(ctx->cpu)) | |
977 | rq->mq_ctx = ctx = current_ctx; | |
320ae51f | 978 | |
320ae51f JA |
979 | hctx = q->mq_ops->map_queue(q, ctx->cpu); |
980 | ||
eeabc850 CH |
981 | if (rq->cmd_flags & (REQ_FLUSH | REQ_FUA) && |
982 | !(rq->cmd_flags & (REQ_FLUSH_SEQ))) { | |
320ae51f JA |
983 | blk_insert_flush(rq); |
984 | } else { | |
320ae51f | 985 | spin_lock(&ctx->lock); |
72a0a36e | 986 | __blk_mq_insert_request(hctx, rq, at_head); |
320ae51f | 987 | spin_unlock(&ctx->lock); |
320ae51f JA |
988 | } |
989 | ||
320ae51f JA |
990 | if (run_queue) |
991 | blk_mq_run_hw_queue(hctx, async); | |
e4043dcf JA |
992 | |
993 | blk_mq_put_ctx(current_ctx); | |
320ae51f JA |
994 | } |
995 | ||
996 | static void blk_mq_insert_requests(struct request_queue *q, | |
997 | struct blk_mq_ctx *ctx, | |
998 | struct list_head *list, | |
999 | int depth, | |
1000 | bool from_schedule) | |
1001 | ||
1002 | { | |
1003 | struct blk_mq_hw_ctx *hctx; | |
1004 | struct blk_mq_ctx *current_ctx; | |
1005 | ||
1006 | trace_block_unplug(q, depth, !from_schedule); | |
1007 | ||
1008 | current_ctx = blk_mq_get_ctx(q); | |
1009 | ||
1010 | if (!cpu_online(ctx->cpu)) | |
1011 | ctx = current_ctx; | |
1012 | hctx = q->mq_ops->map_queue(q, ctx->cpu); | |
1013 | ||
1014 | /* | |
1015 | * preemption doesn't flush plug list, so it's possible ctx->cpu is | |
1016 | * offline now | |
1017 | */ | |
1018 | spin_lock(&ctx->lock); | |
1019 | while (!list_empty(list)) { | |
1020 | struct request *rq; | |
1021 | ||
1022 | rq = list_first_entry(list, struct request, queuelist); | |
1023 | list_del_init(&rq->queuelist); | |
1024 | rq->mq_ctx = ctx; | |
72a0a36e | 1025 | __blk_mq_insert_request(hctx, rq, false); |
320ae51f JA |
1026 | } |
1027 | spin_unlock(&ctx->lock); | |
1028 | ||
320ae51f | 1029 | blk_mq_run_hw_queue(hctx, from_schedule); |
e4043dcf | 1030 | blk_mq_put_ctx(current_ctx); |
320ae51f JA |
1031 | } |
1032 | ||
1033 | static int plug_ctx_cmp(void *priv, struct list_head *a, struct list_head *b) | |
1034 | { | |
1035 | struct request *rqa = container_of(a, struct request, queuelist); | |
1036 | struct request *rqb = container_of(b, struct request, queuelist); | |
1037 | ||
1038 | return !(rqa->mq_ctx < rqb->mq_ctx || | |
1039 | (rqa->mq_ctx == rqb->mq_ctx && | |
1040 | blk_rq_pos(rqa) < blk_rq_pos(rqb))); | |
1041 | } | |
1042 | ||
1043 | void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule) | |
1044 | { | |
1045 | struct blk_mq_ctx *this_ctx; | |
1046 | struct request_queue *this_q; | |
1047 | struct request *rq; | |
1048 | LIST_HEAD(list); | |
1049 | LIST_HEAD(ctx_list); | |
1050 | unsigned int depth; | |
1051 | ||
1052 | list_splice_init(&plug->mq_list, &list); | |
1053 | ||
1054 | list_sort(NULL, &list, plug_ctx_cmp); | |
1055 | ||
1056 | this_q = NULL; | |
1057 | this_ctx = NULL; | |
1058 | depth = 0; | |
1059 | ||
1060 | while (!list_empty(&list)) { | |
1061 | rq = list_entry_rq(list.next); | |
1062 | list_del_init(&rq->queuelist); | |
1063 | BUG_ON(!rq->q); | |
1064 | if (rq->mq_ctx != this_ctx) { | |
1065 | if (this_ctx) { | |
1066 | blk_mq_insert_requests(this_q, this_ctx, | |
1067 | &ctx_list, depth, | |
1068 | from_schedule); | |
1069 | } | |
1070 | ||
1071 | this_ctx = rq->mq_ctx; | |
1072 | this_q = rq->q; | |
1073 | depth = 0; | |
1074 | } | |
1075 | ||
1076 | depth++; | |
1077 | list_add_tail(&rq->queuelist, &ctx_list); | |
1078 | } | |
1079 | ||
1080 | /* | |
1081 | * If 'this_ctx' is set, we know we have entries to complete | |
1082 | * on 'ctx_list'. Do those. | |
1083 | */ | |
1084 | if (this_ctx) { | |
1085 | blk_mq_insert_requests(this_q, this_ctx, &ctx_list, depth, | |
1086 | from_schedule); | |
1087 | } | |
1088 | } | |
1089 | ||
1090 | static void blk_mq_bio_to_request(struct request *rq, struct bio *bio) | |
1091 | { | |
1092 | init_request_from_bio(rq, bio); | |
4b570521 | 1093 | |
3ee32372 | 1094 | if (blk_do_io_stat(rq)) |
4b570521 | 1095 | blk_account_io_start(rq, 1); |
320ae51f JA |
1096 | } |
1097 | ||
07068d5b JA |
1098 | static inline bool blk_mq_merge_queue_io(struct blk_mq_hw_ctx *hctx, |
1099 | struct blk_mq_ctx *ctx, | |
1100 | struct request *rq, struct bio *bio) | |
320ae51f | 1101 | { |
07068d5b | 1102 | struct request_queue *q = hctx->queue; |
320ae51f | 1103 | |
07068d5b JA |
1104 | if (!(hctx->flags & BLK_MQ_F_SHOULD_MERGE)) { |
1105 | blk_mq_bio_to_request(rq, bio); | |
1106 | spin_lock(&ctx->lock); | |
1107 | insert_rq: | |
1108 | __blk_mq_insert_request(hctx, rq, false); | |
1109 | spin_unlock(&ctx->lock); | |
1110 | return false; | |
1111 | } else { | |
1112 | spin_lock(&ctx->lock); | |
1113 | if (!blk_mq_attempt_merge(q, ctx, bio)) { | |
1114 | blk_mq_bio_to_request(rq, bio); | |
1115 | goto insert_rq; | |
1116 | } | |
320ae51f | 1117 | |
07068d5b JA |
1118 | spin_unlock(&ctx->lock); |
1119 | __blk_mq_free_request(hctx, ctx, rq); | |
1120 | return true; | |
14ec77f3 | 1121 | } |
07068d5b | 1122 | } |
14ec77f3 | 1123 | |
07068d5b JA |
1124 | struct blk_map_ctx { |
1125 | struct blk_mq_hw_ctx *hctx; | |
1126 | struct blk_mq_ctx *ctx; | |
1127 | }; | |
1128 | ||
1129 | static struct request *blk_mq_map_request(struct request_queue *q, | |
1130 | struct bio *bio, | |
1131 | struct blk_map_ctx *data) | |
1132 | { | |
1133 | struct blk_mq_hw_ctx *hctx; | |
1134 | struct blk_mq_ctx *ctx; | |
1135 | struct request *rq; | |
1136 | int rw = bio_data_dir(bio); | |
cb96a42c | 1137 | struct blk_mq_alloc_data alloc_data; |
320ae51f | 1138 | |
07068d5b | 1139 | if (unlikely(blk_mq_queue_enter(q))) { |
320ae51f | 1140 | bio_endio(bio, -EIO); |
07068d5b | 1141 | return NULL; |
320ae51f JA |
1142 | } |
1143 | ||
1144 | ctx = blk_mq_get_ctx(q); | |
1145 | hctx = q->mq_ops->map_queue(q, ctx->cpu); | |
1146 | ||
07068d5b | 1147 | if (rw_is_sync(bio->bi_rw)) |
27fbf4e8 | 1148 | rw |= REQ_SYNC; |
07068d5b | 1149 | |
320ae51f | 1150 | trace_block_getrq(q, bio, rw); |
cb96a42c ML |
1151 | blk_mq_set_alloc_data(&alloc_data, q, GFP_ATOMIC, false, ctx, |
1152 | hctx); | |
1153 | rq = __blk_mq_alloc_request(&alloc_data, rw); | |
5dee8577 | 1154 | if (unlikely(!rq)) { |
793597a6 | 1155 | __blk_mq_run_hw_queue(hctx); |
320ae51f JA |
1156 | blk_mq_put_ctx(ctx); |
1157 | trace_block_sleeprq(q, bio, rw); | |
793597a6 CH |
1158 | |
1159 | ctx = blk_mq_get_ctx(q); | |
320ae51f | 1160 | hctx = q->mq_ops->map_queue(q, ctx->cpu); |
cb96a42c ML |
1161 | blk_mq_set_alloc_data(&alloc_data, q, |
1162 | __GFP_WAIT|GFP_ATOMIC, false, ctx, hctx); | |
1163 | rq = __blk_mq_alloc_request(&alloc_data, rw); | |
1164 | ctx = alloc_data.ctx; | |
1165 | hctx = alloc_data.hctx; | |
320ae51f JA |
1166 | } |
1167 | ||
1168 | hctx->queued++; | |
07068d5b JA |
1169 | data->hctx = hctx; |
1170 | data->ctx = ctx; | |
1171 | return rq; | |
1172 | } | |
1173 | ||
1174 | /* | |
1175 | * Multiple hardware queue variant. This will not use per-process plugs, | |
1176 | * but will attempt to bypass the hctx queueing if we can go straight to | |
1177 | * hardware for SYNC IO. | |
1178 | */ | |
1179 | static void blk_mq_make_request(struct request_queue *q, struct bio *bio) | |
1180 | { | |
1181 | const int is_sync = rw_is_sync(bio->bi_rw); | |
1182 | const int is_flush_fua = bio->bi_rw & (REQ_FLUSH | REQ_FUA); | |
1183 | struct blk_map_ctx data; | |
1184 | struct request *rq; | |
1185 | ||
1186 | blk_queue_bounce(q, &bio); | |
1187 | ||
1188 | if (bio_integrity_enabled(bio) && bio_integrity_prep(bio)) { | |
1189 | bio_endio(bio, -EIO); | |
1190 | return; | |
1191 | } | |
1192 | ||
1193 | rq = blk_mq_map_request(q, bio, &data); | |
1194 | if (unlikely(!rq)) | |
1195 | return; | |
1196 | ||
1197 | if (unlikely(is_flush_fua)) { | |
1198 | blk_mq_bio_to_request(rq, bio); | |
1199 | blk_insert_flush(rq); | |
1200 | goto run_queue; | |
1201 | } | |
1202 | ||
1203 | if (is_sync) { | |
1204 | int ret; | |
1205 | ||
1206 | blk_mq_bio_to_request(rq, bio); | |
1207 | blk_mq_start_request(rq, true); | |
1208 | ||
1209 | /* | |
1210 | * For OK queue, we are done. For error, kill it. Any other | |
1211 | * error (busy), just add it to our list as we previously | |
1212 | * would have done | |
1213 | */ | |
1214 | ret = q->mq_ops->queue_rq(data.hctx, rq); | |
1215 | if (ret == BLK_MQ_RQ_QUEUE_OK) | |
1216 | goto done; | |
1217 | else { | |
1218 | __blk_mq_requeue_request(rq); | |
1219 | ||
1220 | if (ret == BLK_MQ_RQ_QUEUE_ERROR) { | |
1221 | rq->errors = -EIO; | |
1222 | blk_mq_end_io(rq, rq->errors); | |
1223 | goto done; | |
1224 | } | |
1225 | } | |
1226 | } | |
1227 | ||
1228 | if (!blk_mq_merge_queue_io(data.hctx, data.ctx, rq, bio)) { | |
1229 | /* | |
1230 | * For a SYNC request, send it to the hardware immediately. For | |
1231 | * an ASYNC request, just ensure that we run it later on. The | |
1232 | * latter allows for merging opportunities and more efficient | |
1233 | * dispatching. | |
1234 | */ | |
1235 | run_queue: | |
1236 | blk_mq_run_hw_queue(data.hctx, !is_sync || is_flush_fua); | |
1237 | } | |
1238 | done: | |
1239 | blk_mq_put_ctx(data.ctx); | |
1240 | } | |
1241 | ||
1242 | /* | |
1243 | * Single hardware queue variant. This will attempt to use any per-process | |
1244 | * plug for merging and IO deferral. | |
1245 | */ | |
1246 | static void blk_sq_make_request(struct request_queue *q, struct bio *bio) | |
1247 | { | |
1248 | const int is_sync = rw_is_sync(bio->bi_rw); | |
1249 | const int is_flush_fua = bio->bi_rw & (REQ_FLUSH | REQ_FUA); | |
1250 | unsigned int use_plug, request_count = 0; | |
1251 | struct blk_map_ctx data; | |
1252 | struct request *rq; | |
1253 | ||
1254 | /* | |
1255 | * If we have multiple hardware queues, just go directly to | |
1256 | * one of those for sync IO. | |
1257 | */ | |
1258 | use_plug = !is_flush_fua && !is_sync; | |
1259 | ||
1260 | blk_queue_bounce(q, &bio); | |
1261 | ||
1262 | if (bio_integrity_enabled(bio) && bio_integrity_prep(bio)) { | |
1263 | bio_endio(bio, -EIO); | |
1264 | return; | |
1265 | } | |
1266 | ||
1267 | if (use_plug && !blk_queue_nomerges(q) && | |
1268 | blk_attempt_plug_merge(q, bio, &request_count)) | |
1269 | return; | |
1270 | ||
1271 | rq = blk_mq_map_request(q, bio, &data); | |
ff87bcec JA |
1272 | if (unlikely(!rq)) |
1273 | return; | |
320ae51f JA |
1274 | |
1275 | if (unlikely(is_flush_fua)) { | |
1276 | blk_mq_bio_to_request(rq, bio); | |
320ae51f JA |
1277 | blk_insert_flush(rq); |
1278 | goto run_queue; | |
1279 | } | |
1280 | ||
1281 | /* | |
1282 | * A task plug currently exists. Since this is completely lockless, | |
1283 | * utilize that to temporarily store requests until the task is | |
1284 | * either done or scheduled away. | |
1285 | */ | |
1286 | if (use_plug) { | |
1287 | struct blk_plug *plug = current->plug; | |
1288 | ||
1289 | if (plug) { | |
1290 | blk_mq_bio_to_request(rq, bio); | |
92f399c7 | 1291 | if (list_empty(&plug->mq_list)) |
320ae51f JA |
1292 | trace_block_plug(q); |
1293 | else if (request_count >= BLK_MAX_REQUEST_COUNT) { | |
1294 | blk_flush_plug_list(plug, false); | |
1295 | trace_block_plug(q); | |
1296 | } | |
1297 | list_add_tail(&rq->queuelist, &plug->mq_list); | |
07068d5b | 1298 | blk_mq_put_ctx(data.ctx); |
320ae51f JA |
1299 | return; |
1300 | } | |
1301 | } | |
1302 | ||
07068d5b JA |
1303 | if (!blk_mq_merge_queue_io(data.hctx, data.ctx, rq, bio)) { |
1304 | /* | |
1305 | * For a SYNC request, send it to the hardware immediately. For | |
1306 | * an ASYNC request, just ensure that we run it later on. The | |
1307 | * latter allows for merging opportunities and more efficient | |
1308 | * dispatching. | |
1309 | */ | |
1310 | run_queue: | |
1311 | blk_mq_run_hw_queue(data.hctx, !is_sync || is_flush_fua); | |
320ae51f JA |
1312 | } |
1313 | ||
07068d5b | 1314 | blk_mq_put_ctx(data.ctx); |
320ae51f JA |
1315 | } |
1316 | ||
1317 | /* | |
1318 | * Default mapping to a software queue, since we use one per CPU. | |
1319 | */ | |
1320 | struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q, const int cpu) | |
1321 | { | |
1322 | return q->queue_hw_ctx[q->mq_map[cpu]]; | |
1323 | } | |
1324 | EXPORT_SYMBOL(blk_mq_map_queue); | |
1325 | ||
24d2f903 CH |
1326 | static void blk_mq_free_rq_map(struct blk_mq_tag_set *set, |
1327 | struct blk_mq_tags *tags, unsigned int hctx_idx) | |
95363efd | 1328 | { |
e9b267d9 | 1329 | struct page *page; |
320ae51f | 1330 | |
24d2f903 | 1331 | if (tags->rqs && set->ops->exit_request) { |
e9b267d9 | 1332 | int i; |
320ae51f | 1333 | |
24d2f903 CH |
1334 | for (i = 0; i < tags->nr_tags; i++) { |
1335 | if (!tags->rqs[i]) | |
e9b267d9 | 1336 | continue; |
24d2f903 CH |
1337 | set->ops->exit_request(set->driver_data, tags->rqs[i], |
1338 | hctx_idx, i); | |
e9b267d9 | 1339 | } |
320ae51f | 1340 | } |
320ae51f | 1341 | |
24d2f903 CH |
1342 | while (!list_empty(&tags->page_list)) { |
1343 | page = list_first_entry(&tags->page_list, struct page, lru); | |
6753471c | 1344 | list_del_init(&page->lru); |
320ae51f JA |
1345 | __free_pages(page, page->private); |
1346 | } | |
1347 | ||
24d2f903 | 1348 | kfree(tags->rqs); |
320ae51f | 1349 | |
24d2f903 | 1350 | blk_mq_free_tags(tags); |
320ae51f JA |
1351 | } |
1352 | ||
1353 | static size_t order_to_size(unsigned int order) | |
1354 | { | |
4ca08500 | 1355 | return (size_t)PAGE_SIZE << order; |
320ae51f JA |
1356 | } |
1357 | ||
24d2f903 CH |
1358 | static struct blk_mq_tags *blk_mq_init_rq_map(struct blk_mq_tag_set *set, |
1359 | unsigned int hctx_idx) | |
320ae51f | 1360 | { |
24d2f903 | 1361 | struct blk_mq_tags *tags; |
320ae51f JA |
1362 | unsigned int i, j, entries_per_page, max_order = 4; |
1363 | size_t rq_size, left; | |
1364 | ||
24d2f903 CH |
1365 | tags = blk_mq_init_tags(set->queue_depth, set->reserved_tags, |
1366 | set->numa_node); | |
1367 | if (!tags) | |
1368 | return NULL; | |
320ae51f | 1369 | |
24d2f903 CH |
1370 | INIT_LIST_HEAD(&tags->page_list); |
1371 | ||
1372 | tags->rqs = kmalloc_node(set->queue_depth * sizeof(struct request *), | |
1373 | GFP_KERNEL, set->numa_node); | |
1374 | if (!tags->rqs) { | |
1375 | blk_mq_free_tags(tags); | |
1376 | return NULL; | |
1377 | } | |
320ae51f JA |
1378 | |
1379 | /* | |
1380 | * rq_size is the size of the request plus driver payload, rounded | |
1381 | * to the cacheline size | |
1382 | */ | |
24d2f903 | 1383 | rq_size = round_up(sizeof(struct request) + set->cmd_size, |
320ae51f | 1384 | cache_line_size()); |
24d2f903 | 1385 | left = rq_size * set->queue_depth; |
320ae51f | 1386 | |
24d2f903 | 1387 | for (i = 0; i < set->queue_depth; ) { |
320ae51f JA |
1388 | int this_order = max_order; |
1389 | struct page *page; | |
1390 | int to_do; | |
1391 | void *p; | |
1392 | ||
1393 | while (left < order_to_size(this_order - 1) && this_order) | |
1394 | this_order--; | |
1395 | ||
1396 | do { | |
24d2f903 CH |
1397 | page = alloc_pages_node(set->numa_node, GFP_KERNEL, |
1398 | this_order); | |
320ae51f JA |
1399 | if (page) |
1400 | break; | |
1401 | if (!this_order--) | |
1402 | break; | |
1403 | if (order_to_size(this_order) < rq_size) | |
1404 | break; | |
1405 | } while (1); | |
1406 | ||
1407 | if (!page) | |
24d2f903 | 1408 | goto fail; |
320ae51f JA |
1409 | |
1410 | page->private = this_order; | |
24d2f903 | 1411 | list_add_tail(&page->lru, &tags->page_list); |
320ae51f JA |
1412 | |
1413 | p = page_address(page); | |
1414 | entries_per_page = order_to_size(this_order) / rq_size; | |
24d2f903 | 1415 | to_do = min(entries_per_page, set->queue_depth - i); |
320ae51f JA |
1416 | left -= to_do * rq_size; |
1417 | for (j = 0; j < to_do; j++) { | |
24d2f903 CH |
1418 | tags->rqs[i] = p; |
1419 | if (set->ops->init_request) { | |
1420 | if (set->ops->init_request(set->driver_data, | |
1421 | tags->rqs[i], hctx_idx, i, | |
1422 | set->numa_node)) | |
1423 | goto fail; | |
e9b267d9 CH |
1424 | } |
1425 | ||
320ae51f JA |
1426 | p += rq_size; |
1427 | i++; | |
1428 | } | |
1429 | } | |
1430 | ||
24d2f903 | 1431 | return tags; |
320ae51f | 1432 | |
24d2f903 CH |
1433 | fail: |
1434 | pr_warn("%s: failed to allocate requests\n", __func__); | |
1435 | blk_mq_free_rq_map(set, tags, hctx_idx); | |
1436 | return NULL; | |
320ae51f JA |
1437 | } |
1438 | ||
1429d7c9 JA |
1439 | static void blk_mq_free_bitmap(struct blk_mq_ctxmap *bitmap) |
1440 | { | |
1441 | kfree(bitmap->map); | |
1442 | } | |
1443 | ||
1444 | static int blk_mq_alloc_bitmap(struct blk_mq_ctxmap *bitmap, int node) | |
1445 | { | |
1446 | unsigned int bpw = 8, total, num_maps, i; | |
1447 | ||
1448 | bitmap->bits_per_word = bpw; | |
1449 | ||
1450 | num_maps = ALIGN(nr_cpu_ids, bpw) / bpw; | |
1451 | bitmap->map = kzalloc_node(num_maps * sizeof(struct blk_align_bitmap), | |
1452 | GFP_KERNEL, node); | |
1453 | if (!bitmap->map) | |
1454 | return -ENOMEM; | |
1455 | ||
1456 | bitmap->map_size = num_maps; | |
1457 | ||
1458 | total = nr_cpu_ids; | |
1459 | for (i = 0; i < num_maps; i++) { | |
1460 | bitmap->map[i].depth = min(total, bitmap->bits_per_word); | |
1461 | total -= bitmap->map[i].depth; | |
1462 | } | |
1463 | ||
1464 | return 0; | |
1465 | } | |
1466 | ||
484b4061 JA |
1467 | static int blk_mq_hctx_cpu_offline(struct blk_mq_hw_ctx *hctx, int cpu) |
1468 | { | |
1469 | struct request_queue *q = hctx->queue; | |
1470 | struct blk_mq_ctx *ctx; | |
1471 | LIST_HEAD(tmp); | |
1472 | ||
1473 | /* | |
1474 | * Move ctx entries to new CPU, if this one is going away. | |
1475 | */ | |
1476 | ctx = __blk_mq_get_ctx(q, cpu); | |
1477 | ||
1478 | spin_lock(&ctx->lock); | |
1479 | if (!list_empty(&ctx->rq_list)) { | |
1480 | list_splice_init(&ctx->rq_list, &tmp); | |
1481 | blk_mq_hctx_clear_pending(hctx, ctx); | |
1482 | } | |
1483 | spin_unlock(&ctx->lock); | |
1484 | ||
1485 | if (list_empty(&tmp)) | |
1486 | return NOTIFY_OK; | |
1487 | ||
1488 | ctx = blk_mq_get_ctx(q); | |
1489 | spin_lock(&ctx->lock); | |
1490 | ||
1491 | while (!list_empty(&tmp)) { | |
1492 | struct request *rq; | |
1493 | ||
1494 | rq = list_first_entry(&tmp, struct request, queuelist); | |
1495 | rq->mq_ctx = ctx; | |
1496 | list_move_tail(&rq->queuelist, &ctx->rq_list); | |
1497 | } | |
1498 | ||
1499 | hctx = q->mq_ops->map_queue(q, ctx->cpu); | |
1500 | blk_mq_hctx_mark_pending(hctx, ctx); | |
1501 | ||
1502 | spin_unlock(&ctx->lock); | |
1503 | ||
1504 | blk_mq_run_hw_queue(hctx, true); | |
1505 | blk_mq_put_ctx(ctx); | |
1506 | return NOTIFY_OK; | |
1507 | } | |
1508 | ||
1509 | static int blk_mq_hctx_cpu_online(struct blk_mq_hw_ctx *hctx, int cpu) | |
1510 | { | |
1511 | struct request_queue *q = hctx->queue; | |
1512 | struct blk_mq_tag_set *set = q->tag_set; | |
1513 | ||
1514 | if (set->tags[hctx->queue_num]) | |
1515 | return NOTIFY_OK; | |
1516 | ||
1517 | set->tags[hctx->queue_num] = blk_mq_init_rq_map(set, hctx->queue_num); | |
1518 | if (!set->tags[hctx->queue_num]) | |
1519 | return NOTIFY_STOP; | |
1520 | ||
1521 | hctx->tags = set->tags[hctx->queue_num]; | |
1522 | return NOTIFY_OK; | |
1523 | } | |
1524 | ||
1525 | static int blk_mq_hctx_notify(void *data, unsigned long action, | |
1526 | unsigned int cpu) | |
1527 | { | |
1528 | struct blk_mq_hw_ctx *hctx = data; | |
1529 | ||
1530 | if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) | |
1531 | return blk_mq_hctx_cpu_offline(hctx, cpu); | |
1532 | else if (action == CPU_ONLINE || action == CPU_ONLINE_FROZEN) | |
1533 | return blk_mq_hctx_cpu_online(hctx, cpu); | |
1534 | ||
1535 | return NOTIFY_OK; | |
1536 | } | |
1537 | ||
624dbe47 ML |
1538 | static void blk_mq_exit_hw_queues(struct request_queue *q, |
1539 | struct blk_mq_tag_set *set, int nr_queue) | |
1540 | { | |
1541 | struct blk_mq_hw_ctx *hctx; | |
1542 | unsigned int i; | |
1543 | ||
1544 | queue_for_each_hw_ctx(q, hctx, i) { | |
1545 | if (i == nr_queue) | |
1546 | break; | |
1547 | ||
f899fed4 JA |
1548 | blk_mq_tag_idle(hctx); |
1549 | ||
624dbe47 ML |
1550 | if (set->ops->exit_hctx) |
1551 | set->ops->exit_hctx(hctx, i); | |
1552 | ||
1553 | blk_mq_unregister_cpu_notifier(&hctx->cpu_notifier); | |
1554 | kfree(hctx->ctxs); | |
1555 | blk_mq_free_bitmap(&hctx->ctx_map); | |
1556 | } | |
1557 | ||
1558 | } | |
1559 | ||
1560 | static void blk_mq_free_hw_queues(struct request_queue *q, | |
1561 | struct blk_mq_tag_set *set) | |
1562 | { | |
1563 | struct blk_mq_hw_ctx *hctx; | |
1564 | unsigned int i; | |
1565 | ||
1566 | queue_for_each_hw_ctx(q, hctx, i) { | |
1567 | free_cpumask_var(hctx->cpumask); | |
cdef54dd | 1568 | kfree(hctx); |
624dbe47 ML |
1569 | } |
1570 | } | |
1571 | ||
320ae51f | 1572 | static int blk_mq_init_hw_queues(struct request_queue *q, |
24d2f903 | 1573 | struct blk_mq_tag_set *set) |
320ae51f JA |
1574 | { |
1575 | struct blk_mq_hw_ctx *hctx; | |
624dbe47 | 1576 | unsigned int i; |
320ae51f JA |
1577 | |
1578 | /* | |
1579 | * Initialize hardware queues | |
1580 | */ | |
1581 | queue_for_each_hw_ctx(q, hctx, i) { | |
320ae51f JA |
1582 | int node; |
1583 | ||
1584 | node = hctx->numa_node; | |
1585 | if (node == NUMA_NO_NODE) | |
24d2f903 | 1586 | node = hctx->numa_node = set->numa_node; |
320ae51f | 1587 | |
70f4db63 CH |
1588 | INIT_DELAYED_WORK(&hctx->run_work, blk_mq_run_work_fn); |
1589 | INIT_DELAYED_WORK(&hctx->delay_work, blk_mq_delay_work_fn); | |
320ae51f JA |
1590 | spin_lock_init(&hctx->lock); |
1591 | INIT_LIST_HEAD(&hctx->dispatch); | |
1592 | hctx->queue = q; | |
1593 | hctx->queue_num = i; | |
24d2f903 CH |
1594 | hctx->flags = set->flags; |
1595 | hctx->cmd_size = set->cmd_size; | |
320ae51f JA |
1596 | |
1597 | blk_mq_init_cpu_notifier(&hctx->cpu_notifier, | |
1598 | blk_mq_hctx_notify, hctx); | |
1599 | blk_mq_register_cpu_notifier(&hctx->cpu_notifier); | |
1600 | ||
24d2f903 | 1601 | hctx->tags = set->tags[i]; |
320ae51f JA |
1602 | |
1603 | /* | |
1604 | * Allocate space for all possible cpus to avoid allocation in | |
1605 | * runtime | |
1606 | */ | |
1607 | hctx->ctxs = kmalloc_node(nr_cpu_ids * sizeof(void *), | |
1608 | GFP_KERNEL, node); | |
1609 | if (!hctx->ctxs) | |
1610 | break; | |
1611 | ||
1429d7c9 | 1612 | if (blk_mq_alloc_bitmap(&hctx->ctx_map, node)) |
320ae51f JA |
1613 | break; |
1614 | ||
320ae51f JA |
1615 | hctx->nr_ctx = 0; |
1616 | ||
24d2f903 CH |
1617 | if (set->ops->init_hctx && |
1618 | set->ops->init_hctx(hctx, set->driver_data, i)) | |
320ae51f JA |
1619 | break; |
1620 | } | |
1621 | ||
1622 | if (i == q->nr_hw_queues) | |
1623 | return 0; | |
1624 | ||
1625 | /* | |
1626 | * Init failed | |
1627 | */ | |
624dbe47 | 1628 | blk_mq_exit_hw_queues(q, set, i); |
320ae51f JA |
1629 | |
1630 | return 1; | |
1631 | } | |
1632 | ||
1633 | static void blk_mq_init_cpu_queues(struct request_queue *q, | |
1634 | unsigned int nr_hw_queues) | |
1635 | { | |
1636 | unsigned int i; | |
1637 | ||
1638 | for_each_possible_cpu(i) { | |
1639 | struct blk_mq_ctx *__ctx = per_cpu_ptr(q->queue_ctx, i); | |
1640 | struct blk_mq_hw_ctx *hctx; | |
1641 | ||
1642 | memset(__ctx, 0, sizeof(*__ctx)); | |
1643 | __ctx->cpu = i; | |
1644 | spin_lock_init(&__ctx->lock); | |
1645 | INIT_LIST_HEAD(&__ctx->rq_list); | |
1646 | __ctx->queue = q; | |
1647 | ||
1648 | /* If the cpu isn't online, the cpu is mapped to first hctx */ | |
320ae51f JA |
1649 | if (!cpu_online(i)) |
1650 | continue; | |
1651 | ||
e4043dcf JA |
1652 | hctx = q->mq_ops->map_queue(q, i); |
1653 | cpumask_set_cpu(i, hctx->cpumask); | |
1654 | hctx->nr_ctx++; | |
1655 | ||
320ae51f JA |
1656 | /* |
1657 | * Set local node, IFF we have more than one hw queue. If | |
1658 | * not, we remain on the home node of the device | |
1659 | */ | |
1660 | if (nr_hw_queues > 1 && hctx->numa_node == NUMA_NO_NODE) | |
1661 | hctx->numa_node = cpu_to_node(i); | |
1662 | } | |
1663 | } | |
1664 | ||
1665 | static void blk_mq_map_swqueue(struct request_queue *q) | |
1666 | { | |
1667 | unsigned int i; | |
1668 | struct blk_mq_hw_ctx *hctx; | |
1669 | struct blk_mq_ctx *ctx; | |
1670 | ||
1671 | queue_for_each_hw_ctx(q, hctx, i) { | |
e4043dcf | 1672 | cpumask_clear(hctx->cpumask); |
320ae51f JA |
1673 | hctx->nr_ctx = 0; |
1674 | } | |
1675 | ||
1676 | /* | |
1677 | * Map software to hardware queues | |
1678 | */ | |
1679 | queue_for_each_ctx(q, ctx, i) { | |
1680 | /* If the cpu isn't online, the cpu is mapped to first hctx */ | |
e4043dcf JA |
1681 | if (!cpu_online(i)) |
1682 | continue; | |
1683 | ||
320ae51f | 1684 | hctx = q->mq_ops->map_queue(q, i); |
e4043dcf | 1685 | cpumask_set_cpu(i, hctx->cpumask); |
320ae51f JA |
1686 | ctx->index_hw = hctx->nr_ctx; |
1687 | hctx->ctxs[hctx->nr_ctx++] = ctx; | |
1688 | } | |
506e931f JA |
1689 | |
1690 | queue_for_each_hw_ctx(q, hctx, i) { | |
484b4061 JA |
1691 | /* |
1692 | * If not software queues are mapped to this hardware queue, | |
1693 | * disable it and free the request entries | |
1694 | */ | |
1695 | if (!hctx->nr_ctx) { | |
1696 | struct blk_mq_tag_set *set = q->tag_set; | |
1697 | ||
1698 | if (set->tags[i]) { | |
1699 | blk_mq_free_rq_map(set, set->tags[i], i); | |
1700 | set->tags[i] = NULL; | |
1701 | hctx->tags = NULL; | |
1702 | } | |
1703 | continue; | |
1704 | } | |
1705 | ||
1706 | /* | |
1707 | * Initialize batch roundrobin counts | |
1708 | */ | |
506e931f JA |
1709 | hctx->next_cpu = cpumask_first(hctx->cpumask); |
1710 | hctx->next_cpu_batch = BLK_MQ_CPU_WORK_BATCH; | |
1711 | } | |
320ae51f JA |
1712 | } |
1713 | ||
0d2602ca JA |
1714 | static void blk_mq_update_tag_set_depth(struct blk_mq_tag_set *set) |
1715 | { | |
1716 | struct blk_mq_hw_ctx *hctx; | |
1717 | struct request_queue *q; | |
1718 | bool shared; | |
1719 | int i; | |
1720 | ||
1721 | if (set->tag_list.next == set->tag_list.prev) | |
1722 | shared = false; | |
1723 | else | |
1724 | shared = true; | |
1725 | ||
1726 | list_for_each_entry(q, &set->tag_list, tag_set_list) { | |
1727 | blk_mq_freeze_queue(q); | |
1728 | ||
1729 | queue_for_each_hw_ctx(q, hctx, i) { | |
1730 | if (shared) | |
1731 | hctx->flags |= BLK_MQ_F_TAG_SHARED; | |
1732 | else | |
1733 | hctx->flags &= ~BLK_MQ_F_TAG_SHARED; | |
1734 | } | |
1735 | blk_mq_unfreeze_queue(q); | |
1736 | } | |
1737 | } | |
1738 | ||
1739 | static void blk_mq_del_queue_tag_set(struct request_queue *q) | |
1740 | { | |
1741 | struct blk_mq_tag_set *set = q->tag_set; | |
1742 | ||
1743 | blk_mq_freeze_queue(q); | |
1744 | ||
1745 | mutex_lock(&set->tag_list_lock); | |
1746 | list_del_init(&q->tag_set_list); | |
1747 | blk_mq_update_tag_set_depth(set); | |
1748 | mutex_unlock(&set->tag_list_lock); | |
1749 | ||
1750 | blk_mq_unfreeze_queue(q); | |
1751 | } | |
1752 | ||
1753 | static void blk_mq_add_queue_tag_set(struct blk_mq_tag_set *set, | |
1754 | struct request_queue *q) | |
1755 | { | |
1756 | q->tag_set = set; | |
1757 | ||
1758 | mutex_lock(&set->tag_list_lock); | |
1759 | list_add_tail(&q->tag_set_list, &set->tag_list); | |
1760 | blk_mq_update_tag_set_depth(set); | |
1761 | mutex_unlock(&set->tag_list_lock); | |
1762 | } | |
1763 | ||
24d2f903 | 1764 | struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *set) |
320ae51f JA |
1765 | { |
1766 | struct blk_mq_hw_ctx **hctxs; | |
e6cdb092 | 1767 | struct blk_mq_ctx __percpu *ctx; |
320ae51f | 1768 | struct request_queue *q; |
f14bbe77 | 1769 | unsigned int *map; |
320ae51f JA |
1770 | int i; |
1771 | ||
320ae51f JA |
1772 | ctx = alloc_percpu(struct blk_mq_ctx); |
1773 | if (!ctx) | |
1774 | return ERR_PTR(-ENOMEM); | |
1775 | ||
24d2f903 CH |
1776 | hctxs = kmalloc_node(set->nr_hw_queues * sizeof(*hctxs), GFP_KERNEL, |
1777 | set->numa_node); | |
320ae51f JA |
1778 | |
1779 | if (!hctxs) | |
1780 | goto err_percpu; | |
1781 | ||
f14bbe77 JA |
1782 | map = blk_mq_make_queue_map(set); |
1783 | if (!map) | |
1784 | goto err_map; | |
1785 | ||
24d2f903 | 1786 | for (i = 0; i < set->nr_hw_queues; i++) { |
f14bbe77 JA |
1787 | int node = blk_mq_hw_queue_to_node(map, i); |
1788 | ||
cdef54dd CH |
1789 | hctxs[i] = kzalloc_node(sizeof(struct blk_mq_hw_ctx), |
1790 | GFP_KERNEL, node); | |
320ae51f JA |
1791 | if (!hctxs[i]) |
1792 | goto err_hctxs; | |
1793 | ||
e4043dcf JA |
1794 | if (!zalloc_cpumask_var(&hctxs[i]->cpumask, GFP_KERNEL)) |
1795 | goto err_hctxs; | |
1796 | ||
0d2602ca | 1797 | atomic_set(&hctxs[i]->nr_active, 0); |
f14bbe77 | 1798 | hctxs[i]->numa_node = node; |
320ae51f JA |
1799 | hctxs[i]->queue_num = i; |
1800 | } | |
1801 | ||
24d2f903 | 1802 | q = blk_alloc_queue_node(GFP_KERNEL, set->numa_node); |
320ae51f JA |
1803 | if (!q) |
1804 | goto err_hctxs; | |
1805 | ||
3d2936f4 ML |
1806 | if (percpu_counter_init(&q->mq_usage_counter, 0)) |
1807 | goto err_map; | |
1808 | ||
320ae51f JA |
1809 | setup_timer(&q->timeout, blk_mq_rq_timer, (unsigned long) q); |
1810 | blk_queue_rq_timeout(q, 30000); | |
1811 | ||
1812 | q->nr_queues = nr_cpu_ids; | |
24d2f903 | 1813 | q->nr_hw_queues = set->nr_hw_queues; |
f14bbe77 | 1814 | q->mq_map = map; |
320ae51f JA |
1815 | |
1816 | q->queue_ctx = ctx; | |
1817 | q->queue_hw_ctx = hctxs; | |
1818 | ||
24d2f903 | 1819 | q->mq_ops = set->ops; |
94eddfbe | 1820 | q->queue_flags |= QUEUE_FLAG_MQ_DEFAULT; |
320ae51f | 1821 | |
05f1dd53 JA |
1822 | if (!(set->flags & BLK_MQ_F_SG_MERGE)) |
1823 | q->queue_flags |= 1 << QUEUE_FLAG_NO_SG_MERGE; | |
1824 | ||
1be036e9 CH |
1825 | q->sg_reserved_size = INT_MAX; |
1826 | ||
6fca6a61 CH |
1827 | INIT_WORK(&q->requeue_work, blk_mq_requeue_work); |
1828 | INIT_LIST_HEAD(&q->requeue_list); | |
1829 | spin_lock_init(&q->requeue_lock); | |
1830 | ||
07068d5b JA |
1831 | if (q->nr_hw_queues > 1) |
1832 | blk_queue_make_request(q, blk_mq_make_request); | |
1833 | else | |
1834 | blk_queue_make_request(q, blk_sq_make_request); | |
1835 | ||
87ee7b11 | 1836 | blk_queue_rq_timed_out(q, blk_mq_rq_timed_out); |
24d2f903 CH |
1837 | if (set->timeout) |
1838 | blk_queue_rq_timeout(q, set->timeout); | |
320ae51f | 1839 | |
eba71768 JA |
1840 | /* |
1841 | * Do this after blk_queue_make_request() overrides it... | |
1842 | */ | |
1843 | q->nr_requests = set->queue_depth; | |
1844 | ||
24d2f903 CH |
1845 | if (set->ops->complete) |
1846 | blk_queue_softirq_done(q, set->ops->complete); | |
30a91cb4 | 1847 | |
320ae51f | 1848 | blk_mq_init_flush(q); |
24d2f903 | 1849 | blk_mq_init_cpu_queues(q, set->nr_hw_queues); |
320ae51f | 1850 | |
24d2f903 CH |
1851 | q->flush_rq = kzalloc(round_up(sizeof(struct request) + |
1852 | set->cmd_size, cache_line_size()), | |
1853 | GFP_KERNEL); | |
18741986 | 1854 | if (!q->flush_rq) |
320ae51f JA |
1855 | goto err_hw; |
1856 | ||
24d2f903 | 1857 | if (blk_mq_init_hw_queues(q, set)) |
18741986 CH |
1858 | goto err_flush_rq; |
1859 | ||
320ae51f JA |
1860 | mutex_lock(&all_q_mutex); |
1861 | list_add_tail(&q->all_q_node, &all_q_list); | |
1862 | mutex_unlock(&all_q_mutex); | |
1863 | ||
0d2602ca JA |
1864 | blk_mq_add_queue_tag_set(set, q); |
1865 | ||
484b4061 JA |
1866 | blk_mq_map_swqueue(q); |
1867 | ||
320ae51f | 1868 | return q; |
18741986 CH |
1869 | |
1870 | err_flush_rq: | |
1871 | kfree(q->flush_rq); | |
320ae51f | 1872 | err_hw: |
320ae51f JA |
1873 | blk_cleanup_queue(q); |
1874 | err_hctxs: | |
f14bbe77 | 1875 | kfree(map); |
24d2f903 | 1876 | for (i = 0; i < set->nr_hw_queues; i++) { |
320ae51f JA |
1877 | if (!hctxs[i]) |
1878 | break; | |
e4043dcf | 1879 | free_cpumask_var(hctxs[i]->cpumask); |
cdef54dd | 1880 | kfree(hctxs[i]); |
320ae51f | 1881 | } |
f14bbe77 | 1882 | err_map: |
320ae51f JA |
1883 | kfree(hctxs); |
1884 | err_percpu: | |
1885 | free_percpu(ctx); | |
1886 | return ERR_PTR(-ENOMEM); | |
1887 | } | |
1888 | EXPORT_SYMBOL(blk_mq_init_queue); | |
1889 | ||
1890 | void blk_mq_free_queue(struct request_queue *q) | |
1891 | { | |
624dbe47 | 1892 | struct blk_mq_tag_set *set = q->tag_set; |
320ae51f | 1893 | |
0d2602ca JA |
1894 | blk_mq_del_queue_tag_set(q); |
1895 | ||
624dbe47 ML |
1896 | blk_mq_exit_hw_queues(q, set, set->nr_hw_queues); |
1897 | blk_mq_free_hw_queues(q, set); | |
320ae51f | 1898 | |
3d2936f4 ML |
1899 | percpu_counter_destroy(&q->mq_usage_counter); |
1900 | ||
320ae51f JA |
1901 | free_percpu(q->queue_ctx); |
1902 | kfree(q->queue_hw_ctx); | |
1903 | kfree(q->mq_map); | |
1904 | ||
1905 | q->queue_ctx = NULL; | |
1906 | q->queue_hw_ctx = NULL; | |
1907 | q->mq_map = NULL; | |
1908 | ||
1909 | mutex_lock(&all_q_mutex); | |
1910 | list_del_init(&q->all_q_node); | |
1911 | mutex_unlock(&all_q_mutex); | |
1912 | } | |
320ae51f JA |
1913 | |
1914 | /* Basically redo blk_mq_init_queue with queue frozen */ | |
f618ef7c | 1915 | static void blk_mq_queue_reinit(struct request_queue *q) |
320ae51f JA |
1916 | { |
1917 | blk_mq_freeze_queue(q); | |
1918 | ||
67aec14c JA |
1919 | blk_mq_sysfs_unregister(q); |
1920 | ||
320ae51f JA |
1921 | blk_mq_update_queue_map(q->mq_map, q->nr_hw_queues); |
1922 | ||
1923 | /* | |
1924 | * redo blk_mq_init_cpu_queues and blk_mq_init_hw_queues. FIXME: maybe | |
1925 | * we should change hctx numa_node according to new topology (this | |
1926 | * involves free and re-allocate memory, worthy doing?) | |
1927 | */ | |
1928 | ||
1929 | blk_mq_map_swqueue(q); | |
1930 | ||
67aec14c JA |
1931 | blk_mq_sysfs_register(q); |
1932 | ||
320ae51f JA |
1933 | blk_mq_unfreeze_queue(q); |
1934 | } | |
1935 | ||
f618ef7c PG |
1936 | static int blk_mq_queue_reinit_notify(struct notifier_block *nb, |
1937 | unsigned long action, void *hcpu) | |
320ae51f JA |
1938 | { |
1939 | struct request_queue *q; | |
1940 | ||
1941 | /* | |
9fccfed8 JA |
1942 | * Before new mappings are established, hotadded cpu might already |
1943 | * start handling requests. This doesn't break anything as we map | |
1944 | * offline CPUs to first hardware queue. We will re-init the queue | |
1945 | * below to get optimal settings. | |
320ae51f JA |
1946 | */ |
1947 | if (action != CPU_DEAD && action != CPU_DEAD_FROZEN && | |
1948 | action != CPU_ONLINE && action != CPU_ONLINE_FROZEN) | |
1949 | return NOTIFY_OK; | |
1950 | ||
1951 | mutex_lock(&all_q_mutex); | |
1952 | list_for_each_entry(q, &all_q_list, all_q_node) | |
1953 | blk_mq_queue_reinit(q); | |
1954 | mutex_unlock(&all_q_mutex); | |
1955 | return NOTIFY_OK; | |
1956 | } | |
1957 | ||
a4391c64 JA |
1958 | /* |
1959 | * Alloc a tag set to be associated with one or more request queues. | |
1960 | * May fail with EINVAL for various error conditions. May adjust the | |
1961 | * requested depth down, if if it too large. In that case, the set | |
1962 | * value will be stored in set->queue_depth. | |
1963 | */ | |
24d2f903 CH |
1964 | int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set) |
1965 | { | |
1966 | int i; | |
1967 | ||
1968 | if (!set->nr_hw_queues) | |
1969 | return -EINVAL; | |
a4391c64 | 1970 | if (!set->queue_depth) |
24d2f903 CH |
1971 | return -EINVAL; |
1972 | if (set->queue_depth < set->reserved_tags + BLK_MQ_TAG_MIN) | |
1973 | return -EINVAL; | |
1974 | ||
cdef54dd | 1975 | if (!set->nr_hw_queues || !set->ops->queue_rq || !set->ops->map_queue) |
24d2f903 CH |
1976 | return -EINVAL; |
1977 | ||
a4391c64 JA |
1978 | if (set->queue_depth > BLK_MQ_MAX_DEPTH) { |
1979 | pr_info("blk-mq: reduced tag depth to %u\n", | |
1980 | BLK_MQ_MAX_DEPTH); | |
1981 | set->queue_depth = BLK_MQ_MAX_DEPTH; | |
1982 | } | |
24d2f903 | 1983 | |
48479005 ML |
1984 | set->tags = kmalloc_node(set->nr_hw_queues * |
1985 | sizeof(struct blk_mq_tags *), | |
24d2f903 CH |
1986 | GFP_KERNEL, set->numa_node); |
1987 | if (!set->tags) | |
1988 | goto out; | |
1989 | ||
1990 | for (i = 0; i < set->nr_hw_queues; i++) { | |
1991 | set->tags[i] = blk_mq_init_rq_map(set, i); | |
1992 | if (!set->tags[i]) | |
1993 | goto out_unwind; | |
1994 | } | |
1995 | ||
0d2602ca JA |
1996 | mutex_init(&set->tag_list_lock); |
1997 | INIT_LIST_HEAD(&set->tag_list); | |
1998 | ||
24d2f903 CH |
1999 | return 0; |
2000 | ||
2001 | out_unwind: | |
2002 | while (--i >= 0) | |
2003 | blk_mq_free_rq_map(set, set->tags[i], i); | |
2004 | out: | |
2005 | return -ENOMEM; | |
2006 | } | |
2007 | EXPORT_SYMBOL(blk_mq_alloc_tag_set); | |
2008 | ||
2009 | void blk_mq_free_tag_set(struct blk_mq_tag_set *set) | |
2010 | { | |
2011 | int i; | |
2012 | ||
484b4061 JA |
2013 | for (i = 0; i < set->nr_hw_queues; i++) { |
2014 | if (set->tags[i]) | |
2015 | blk_mq_free_rq_map(set, set->tags[i], i); | |
2016 | } | |
2017 | ||
981bd189 | 2018 | kfree(set->tags); |
24d2f903 CH |
2019 | } |
2020 | EXPORT_SYMBOL(blk_mq_free_tag_set); | |
2021 | ||
e3a2b3f9 JA |
2022 | int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr) |
2023 | { | |
2024 | struct blk_mq_tag_set *set = q->tag_set; | |
2025 | struct blk_mq_hw_ctx *hctx; | |
2026 | int i, ret; | |
2027 | ||
2028 | if (!set || nr > set->queue_depth) | |
2029 | return -EINVAL; | |
2030 | ||
2031 | ret = 0; | |
2032 | queue_for_each_hw_ctx(q, hctx, i) { | |
2033 | ret = blk_mq_tag_update_depth(hctx->tags, nr); | |
2034 | if (ret) | |
2035 | break; | |
2036 | } | |
2037 | ||
2038 | if (!ret) | |
2039 | q->nr_requests = nr; | |
2040 | ||
2041 | return ret; | |
2042 | } | |
2043 | ||
676141e4 JA |
2044 | void blk_mq_disable_hotplug(void) |
2045 | { | |
2046 | mutex_lock(&all_q_mutex); | |
2047 | } | |
2048 | ||
2049 | void blk_mq_enable_hotplug(void) | |
2050 | { | |
2051 | mutex_unlock(&all_q_mutex); | |
2052 | } | |
2053 | ||
320ae51f JA |
2054 | static int __init blk_mq_init(void) |
2055 | { | |
320ae51f JA |
2056 | blk_mq_cpu_init(); |
2057 | ||
2058 | /* Must be called after percpu_counter_hotcpu_callback() */ | |
2059 | hotcpu_notifier(blk_mq_queue_reinit_notify, -10); | |
2060 | ||
2061 | return 0; | |
2062 | } | |
2063 | subsys_initcall(blk_mq_init); |