Commit | Line | Data |
---|---|---|
3dcf60bc | 1 | // SPDX-License-Identifier: GPL-2.0 |
75bb4625 | 2 | /* |
88459642 OS |
3 | * Tag allocation using scalable bitmaps. Uses active queue tracking to support |
4 | * fairer distribution of tags between multiple submitters when a shared tag map | |
5 | * is used. | |
75bb4625 JA |
6 | * |
7 | * Copyright (C) 2013-2014 Jens Axboe | |
8 | */ | |
320ae51f JA |
9 | #include <linux/kernel.h> |
10 | #include <linux/module.h> | |
320ae51f JA |
11 | |
12 | #include <linux/blk-mq.h> | |
13 | #include "blk.h" | |
14 | #include "blk-mq.h" | |
15 | #include "blk-mq-tag.h" | |
16 | ||
320ae51f JA |
17 | bool blk_mq_has_free_tags(struct blk_mq_tags *tags) |
18 | { | |
4bb659b1 JA |
19 | if (!tags) |
20 | return true; | |
21 | ||
88459642 | 22 | return sbitmap_any_bit_clear(&tags->bitmap_tags.sb); |
0d2602ca JA |
23 | } |
24 | ||
25 | /* | |
26 | * If a previously inactive queue goes active, bump the active user count. | |
d263ed99 JW |
27 | * We need to do this before try to allocate driver tag, then even if fail |
28 | * to get tag when first time, the other shared-tag users could reserve | |
29 | * budget for it. | |
0d2602ca JA |
30 | */ |
31 | bool __blk_mq_tag_busy(struct blk_mq_hw_ctx *hctx) | |
32 | { | |
33 | if (!test_bit(BLK_MQ_S_TAG_ACTIVE, &hctx->state) && | |
34 | !test_and_set_bit(BLK_MQ_S_TAG_ACTIVE, &hctx->state)) | |
35 | atomic_inc(&hctx->tags->active_queues); | |
36 | ||
37 | return true; | |
38 | } | |
39 | ||
40 | /* | |
aed3ea94 | 41 | * Wakeup all potentially sleeping on tags |
0d2602ca | 42 | */ |
aed3ea94 | 43 | void blk_mq_tag_wakeup_all(struct blk_mq_tags *tags, bool include_reserve) |
0d2602ca | 44 | { |
88459642 OS |
45 | sbitmap_queue_wake_all(&tags->bitmap_tags); |
46 | if (include_reserve) | |
47 | sbitmap_queue_wake_all(&tags->breserved_tags); | |
0d2602ca JA |
48 | } |
49 | ||
e3a2b3f9 JA |
50 | /* |
51 | * If a previously busy queue goes inactive, potential waiters could now | |
52 | * be allowed to queue. Wake them up and check. | |
53 | */ | |
54 | void __blk_mq_tag_idle(struct blk_mq_hw_ctx *hctx) | |
55 | { | |
56 | struct blk_mq_tags *tags = hctx->tags; | |
57 | ||
58 | if (!test_and_clear_bit(BLK_MQ_S_TAG_ACTIVE, &hctx->state)) | |
59 | return; | |
60 | ||
61 | atomic_dec(&tags->active_queues); | |
62 | ||
aed3ea94 | 63 | blk_mq_tag_wakeup_all(tags, false); |
e3a2b3f9 JA |
64 | } |
65 | ||
0d2602ca JA |
66 | /* |
67 | * For shared tag users, we track the number of currently active users | |
68 | * and attempt to provide a fair share of the tag depth for each of them. | |
69 | */ | |
70 | static inline bool hctx_may_queue(struct blk_mq_hw_ctx *hctx, | |
88459642 | 71 | struct sbitmap_queue *bt) |
0d2602ca JA |
72 | { |
73 | unsigned int depth, users; | |
74 | ||
75 | if (!hctx || !(hctx->flags & BLK_MQ_F_TAG_SHARED)) | |
76 | return true; | |
77 | if (!test_bit(BLK_MQ_S_TAG_ACTIVE, &hctx->state)) | |
78 | return true; | |
79 | ||
80 | /* | |
81 | * Don't try dividing an ant | |
82 | */ | |
88459642 | 83 | if (bt->sb.depth == 1) |
0d2602ca JA |
84 | return true; |
85 | ||
86 | users = atomic_read(&hctx->tags->active_queues); | |
87 | if (!users) | |
88 | return true; | |
89 | ||
90 | /* | |
91 | * Allow at least some tags | |
92 | */ | |
88459642 | 93 | depth = max((bt->sb.depth + users - 1) / users, 4U); |
0d2602ca JA |
94 | return atomic_read(&hctx->nr_active) < depth; |
95 | } | |
96 | ||
200e86b3 JA |
97 | static int __blk_mq_get_tag(struct blk_mq_alloc_data *data, |
98 | struct sbitmap_queue *bt) | |
4bb659b1 | 99 | { |
200e86b3 JA |
100 | if (!(data->flags & BLK_MQ_REQ_INTERNAL) && |
101 | !hctx_may_queue(data->hctx, bt)) | |
0d2602ca | 102 | return -1; |
229a9287 OS |
103 | if (data->shallow_depth) |
104 | return __sbitmap_queue_get_shallow(bt, data->shallow_depth); | |
105 | else | |
106 | return __sbitmap_queue_get(bt); | |
4bb659b1 JA |
107 | } |
108 | ||
4941115b | 109 | unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data) |
320ae51f | 110 | { |
4941115b JA |
111 | struct blk_mq_tags *tags = blk_mq_tags_from_data(data); |
112 | struct sbitmap_queue *bt; | |
88459642 | 113 | struct sbq_wait_state *ws; |
5d2ee712 | 114 | DEFINE_SBQ_WAIT(wait); |
4941115b | 115 | unsigned int tag_offset; |
320ae51f JA |
116 | int tag; |
117 | ||
4941115b JA |
118 | if (data->flags & BLK_MQ_REQ_RESERVED) { |
119 | if (unlikely(!tags->nr_reserved_tags)) { | |
120 | WARN_ON_ONCE(1); | |
121 | return BLK_MQ_TAG_FAIL; | |
122 | } | |
123 | bt = &tags->breserved_tags; | |
124 | tag_offset = 0; | |
125 | } else { | |
126 | bt = &tags->bitmap_tags; | |
127 | tag_offset = tags->nr_reserved_tags; | |
128 | } | |
129 | ||
200e86b3 | 130 | tag = __blk_mq_get_tag(data, bt); |
4bb659b1 | 131 | if (tag != -1) |
4941115b | 132 | goto found_tag; |
4bb659b1 | 133 | |
6f3b0e8b | 134 | if (data->flags & BLK_MQ_REQ_NOWAIT) |
4941115b | 135 | return BLK_MQ_TAG_FAIL; |
4bb659b1 | 136 | |
4941115b | 137 | ws = bt_wait_ptr(bt, data->hctx); |
4bb659b1 | 138 | do { |
e6fc4649 ML |
139 | struct sbitmap_queue *bt_prev; |
140 | ||
b3223207 BVA |
141 | /* |
142 | * We're out of tags on this hardware queue, kick any | |
143 | * pending IO submits before going to sleep waiting for | |
8cecb07d | 144 | * some to complete. |
b3223207 | 145 | */ |
8cecb07d | 146 | blk_mq_run_hw_queue(data->hctx, false); |
b3223207 | 147 | |
080ff351 JA |
148 | /* |
149 | * Retry tag allocation after running the hardware queue, | |
150 | * as running the queue may also have found completions. | |
151 | */ | |
200e86b3 | 152 | tag = __blk_mq_get_tag(data, bt); |
080ff351 JA |
153 | if (tag != -1) |
154 | break; | |
155 | ||
5d2ee712 | 156 | sbitmap_prepare_to_wait(bt, ws, &wait, TASK_UNINTERRUPTIBLE); |
4e5dff41 JA |
157 | |
158 | tag = __blk_mq_get_tag(data, bt); | |
159 | if (tag != -1) | |
160 | break; | |
161 | ||
e6fc4649 | 162 | bt_prev = bt; |
4bb659b1 | 163 | io_schedule(); |
cb96a42c | 164 | |
5d2ee712 JA |
165 | sbitmap_finish_wait(bt, ws, &wait); |
166 | ||
cb96a42c | 167 | data->ctx = blk_mq_get_ctx(data->q); |
f9afca4d | 168 | data->hctx = blk_mq_map_queue(data->q, data->cmd_flags, |
8ccdf4a3 | 169 | data->ctx); |
4941115b JA |
170 | tags = blk_mq_tags_from_data(data); |
171 | if (data->flags & BLK_MQ_REQ_RESERVED) | |
172 | bt = &tags->breserved_tags; | |
173 | else | |
174 | bt = &tags->bitmap_tags; | |
175 | ||
e6fc4649 ML |
176 | /* |
177 | * If destination hw queue is changed, fake wake up on | |
178 | * previous queue for compensating the wake up miss, so | |
179 | * other allocations on previous queue won't be starved. | |
180 | */ | |
181 | if (bt != bt_prev) | |
182 | sbitmap_queue_wake_up(bt_prev); | |
183 | ||
4941115b | 184 | ws = bt_wait_ptr(bt, data->hctx); |
4bb659b1 JA |
185 | } while (1); |
186 | ||
5d2ee712 | 187 | sbitmap_finish_wait(bt, ws, &wait); |
320ae51f | 188 | |
4941115b JA |
189 | found_tag: |
190 | return tag + tag_offset; | |
320ae51f JA |
191 | } |
192 | ||
4941115b JA |
193 | void blk_mq_put_tag(struct blk_mq_hw_ctx *hctx, struct blk_mq_tags *tags, |
194 | struct blk_mq_ctx *ctx, unsigned int tag) | |
320ae51f | 195 | { |
415b806d | 196 | if (!blk_mq_tag_is_reserved(tags, tag)) { |
4bb659b1 JA |
197 | const int real_tag = tag - tags->nr_reserved_tags; |
198 | ||
70114c39 | 199 | BUG_ON(real_tag >= tags->nr_tags); |
f4a644db | 200 | sbitmap_queue_clear(&tags->bitmap_tags, real_tag, ctx->cpu); |
70114c39 JA |
201 | } else { |
202 | BUG_ON(tag >= tags->nr_reserved_tags); | |
f4a644db | 203 | sbitmap_queue_clear(&tags->breserved_tags, tag, ctx->cpu); |
70114c39 | 204 | } |
320ae51f JA |
205 | } |
206 | ||
88459642 OS |
207 | struct bt_iter_data { |
208 | struct blk_mq_hw_ctx *hctx; | |
209 | busy_iter_fn *fn; | |
210 | void *data; | |
211 | bool reserved; | |
212 | }; | |
213 | ||
214 | static bool bt_iter(struct sbitmap *bitmap, unsigned int bitnr, void *data) | |
320ae51f | 215 | { |
88459642 OS |
216 | struct bt_iter_data *iter_data = data; |
217 | struct blk_mq_hw_ctx *hctx = iter_data->hctx; | |
218 | struct blk_mq_tags *tags = hctx->tags; | |
219 | bool reserved = iter_data->reserved; | |
81481eb4 | 220 | struct request *rq; |
4bb659b1 | 221 | |
88459642 OS |
222 | if (!reserved) |
223 | bitnr += tags->nr_reserved_tags; | |
224 | rq = tags->rqs[bitnr]; | |
4bb659b1 | 225 | |
7f5562d5 JA |
226 | /* |
227 | * We can hit rq == NULL here, because the tagging functions | |
c7b1bf5c | 228 | * test and set the bit before assigning ->rqs[]. |
7f5562d5 JA |
229 | */ |
230 | if (rq && rq->q == hctx->queue) | |
7baa8572 | 231 | return iter_data->fn(hctx, rq, iter_data->data, reserved); |
88459642 OS |
232 | return true; |
233 | } | |
4bb659b1 | 234 | |
c7b1bf5c BVA |
235 | /** |
236 | * bt_for_each - iterate over the requests associated with a hardware queue | |
237 | * @hctx: Hardware queue to examine. | |
238 | * @bt: sbitmap to examine. This is either the breserved_tags member | |
239 | * or the bitmap_tags member of struct blk_mq_tags. | |
240 | * @fn: Pointer to the function that will be called for each request | |
241 | * associated with @hctx that has been assigned a driver tag. | |
242 | * @fn will be called as follows: @fn(@hctx, rq, @data, @reserved) | |
ab11fe5a JA |
243 | * where rq is a pointer to a request. Return true to continue |
244 | * iterating tags, false to stop. | |
c7b1bf5c BVA |
245 | * @data: Will be passed as third argument to @fn. |
246 | * @reserved: Indicates whether @bt is the breserved_tags member or the | |
247 | * bitmap_tags member of struct blk_mq_tags. | |
248 | */ | |
88459642 OS |
249 | static void bt_for_each(struct blk_mq_hw_ctx *hctx, struct sbitmap_queue *bt, |
250 | busy_iter_fn *fn, void *data, bool reserved) | |
251 | { | |
252 | struct bt_iter_data iter_data = { | |
253 | .hctx = hctx, | |
254 | .fn = fn, | |
255 | .data = data, | |
256 | .reserved = reserved, | |
257 | }; | |
258 | ||
259 | sbitmap_for_each_set(&bt->sb, bt_iter, &iter_data); | |
320ae51f JA |
260 | } |
261 | ||
88459642 OS |
262 | struct bt_tags_iter_data { |
263 | struct blk_mq_tags *tags; | |
264 | busy_tag_iter_fn *fn; | |
265 | void *data; | |
266 | bool reserved; | |
267 | }; | |
268 | ||
269 | static bool bt_tags_iter(struct sbitmap *bitmap, unsigned int bitnr, void *data) | |
f26cdc85 | 270 | { |
88459642 OS |
271 | struct bt_tags_iter_data *iter_data = data; |
272 | struct blk_mq_tags *tags = iter_data->tags; | |
273 | bool reserved = iter_data->reserved; | |
f26cdc85 | 274 | struct request *rq; |
f26cdc85 | 275 | |
88459642 OS |
276 | if (!reserved) |
277 | bitnr += tags->nr_reserved_tags; | |
7f5562d5 JA |
278 | |
279 | /* | |
280 | * We can hit rq == NULL here, because the tagging functions | |
281 | * test and set the bit before assining ->rqs[]. | |
282 | */ | |
88459642 | 283 | rq = tags->rqs[bitnr]; |
2d5ba0e2 | 284 | if (rq && blk_mq_request_started(rq)) |
7baa8572 | 285 | return iter_data->fn(rq, iter_data->data, reserved); |
f26cdc85 | 286 | |
88459642 OS |
287 | return true; |
288 | } | |
289 | ||
c7b1bf5c BVA |
290 | /** |
291 | * bt_tags_for_each - iterate over the requests in a tag map | |
292 | * @tags: Tag map to iterate over. | |
293 | * @bt: sbitmap to examine. This is either the breserved_tags member | |
294 | * or the bitmap_tags member of struct blk_mq_tags. | |
295 | * @fn: Pointer to the function that will be called for each started | |
296 | * request. @fn will be called as follows: @fn(rq, @data, | |
ab11fe5a JA |
297 | * @reserved) where rq is a pointer to a request. Return true |
298 | * to continue iterating tags, false to stop. | |
c7b1bf5c BVA |
299 | * @data: Will be passed as second argument to @fn. |
300 | * @reserved: Indicates whether @bt is the breserved_tags member or the | |
301 | * bitmap_tags member of struct blk_mq_tags. | |
302 | */ | |
88459642 OS |
303 | static void bt_tags_for_each(struct blk_mq_tags *tags, struct sbitmap_queue *bt, |
304 | busy_tag_iter_fn *fn, void *data, bool reserved) | |
305 | { | |
306 | struct bt_tags_iter_data iter_data = { | |
307 | .tags = tags, | |
308 | .fn = fn, | |
309 | .data = data, | |
310 | .reserved = reserved, | |
311 | }; | |
312 | ||
313 | if (tags->rqs) | |
314 | sbitmap_for_each_set(&bt->sb, bt_tags_iter, &iter_data); | |
f26cdc85 KB |
315 | } |
316 | ||
c7b1bf5c BVA |
317 | /** |
318 | * blk_mq_all_tag_busy_iter - iterate over all started requests in a tag map | |
319 | * @tags: Tag map to iterate over. | |
320 | * @fn: Pointer to the function that will be called for each started | |
321 | * request. @fn will be called as follows: @fn(rq, @priv, | |
322 | * reserved) where rq is a pointer to a request. 'reserved' | |
ab11fe5a JA |
323 | * indicates whether or not @rq is a reserved request. Return |
324 | * true to continue iterating tags, false to stop. | |
c7b1bf5c BVA |
325 | * @priv: Will be passed as second argument to @fn. |
326 | */ | |
e8f1e163 SG |
327 | static void blk_mq_all_tag_busy_iter(struct blk_mq_tags *tags, |
328 | busy_tag_iter_fn *fn, void *priv) | |
f26cdc85 KB |
329 | { |
330 | if (tags->nr_reserved_tags) | |
88459642 OS |
331 | bt_tags_for_each(tags, &tags->breserved_tags, fn, priv, true); |
332 | bt_tags_for_each(tags, &tags->bitmap_tags, fn, priv, false); | |
f26cdc85 | 333 | } |
f26cdc85 | 334 | |
c7b1bf5c BVA |
335 | /** |
336 | * blk_mq_tagset_busy_iter - iterate over all started requests in a tag set | |
337 | * @tagset: Tag set to iterate over. | |
338 | * @fn: Pointer to the function that will be called for each started | |
339 | * request. @fn will be called as follows: @fn(rq, @priv, | |
340 | * reserved) where rq is a pointer to a request. 'reserved' | |
ab11fe5a JA |
341 | * indicates whether or not @rq is a reserved request. Return |
342 | * true to continue iterating tags, false to stop. | |
c7b1bf5c BVA |
343 | * @priv: Will be passed as second argument to @fn. |
344 | */ | |
e0489487 SG |
345 | void blk_mq_tagset_busy_iter(struct blk_mq_tag_set *tagset, |
346 | busy_tag_iter_fn *fn, void *priv) | |
347 | { | |
348 | int i; | |
349 | ||
350 | for (i = 0; i < tagset->nr_hw_queues; i++) { | |
351 | if (tagset->tags && tagset->tags[i]) | |
352 | blk_mq_all_tag_busy_iter(tagset->tags[i], fn, priv); | |
353 | } | |
354 | } | |
355 | EXPORT_SYMBOL(blk_mq_tagset_busy_iter); | |
356 | ||
c7b1bf5c BVA |
357 | /** |
358 | * blk_mq_queue_tag_busy_iter - iterate over all requests with a driver tag | |
359 | * @q: Request queue to examine. | |
360 | * @fn: Pointer to the function that will be called for each request | |
361 | * on @q. @fn will be called as follows: @fn(hctx, rq, @priv, | |
362 | * reserved) where rq is a pointer to a request and hctx points | |
363 | * to the hardware queue associated with the request. 'reserved' | |
364 | * indicates whether or not @rq is a reserved request. | |
365 | * @priv: Will be passed as third argument to @fn. | |
366 | * | |
367 | * Note: if @q->tag_set is shared with other request queues then @fn will be | |
368 | * called for all requests on all queues that share that tag set and not only | |
369 | * for requests associated with @q. | |
370 | */ | |
0bf6cd5b | 371 | void blk_mq_queue_tag_busy_iter(struct request_queue *q, busy_iter_fn *fn, |
81481eb4 | 372 | void *priv) |
320ae51f | 373 | { |
0bf6cd5b CH |
374 | struct blk_mq_hw_ctx *hctx; |
375 | int i; | |
376 | ||
f5bbbbe4 | 377 | /* |
c7b1bf5c BVA |
378 | * __blk_mq_update_nr_hw_queues() updates nr_hw_queues and queue_hw_ctx |
379 | * while the queue is frozen. So we can use q_usage_counter to avoid | |
380 | * racing with it. __blk_mq_update_nr_hw_queues() uses | |
381 | * synchronize_rcu() to ensure this function left the critical section | |
382 | * below. | |
f5bbbbe4 | 383 | */ |
530ca2c9 | 384 | if (!percpu_ref_tryget(&q->q_usage_counter)) |
f5bbbbe4 | 385 | return; |
0bf6cd5b CH |
386 | |
387 | queue_for_each_hw_ctx(q, hctx, i) { | |
388 | struct blk_mq_tags *tags = hctx->tags; | |
389 | ||
390 | /* | |
c7b1bf5c | 391 | * If no software queues are currently mapped to this |
0bf6cd5b CH |
392 | * hardware queue, there's nothing to check |
393 | */ | |
394 | if (!blk_mq_hw_queue_mapped(hctx)) | |
395 | continue; | |
396 | ||
397 | if (tags->nr_reserved_tags) | |
88459642 OS |
398 | bt_for_each(hctx, &tags->breserved_tags, fn, priv, true); |
399 | bt_for_each(hctx, &tags->bitmap_tags, fn, priv, false); | |
4bb659b1 | 400 | } |
530ca2c9 | 401 | blk_queue_exit(q); |
4bb659b1 JA |
402 | } |
403 | ||
f4a644db OS |
404 | static int bt_alloc(struct sbitmap_queue *bt, unsigned int depth, |
405 | bool round_robin, int node) | |
4bb659b1 | 406 | { |
f4a644db OS |
407 | return sbitmap_queue_init_node(bt, depth, -1, round_robin, GFP_KERNEL, |
408 | node); | |
4bb659b1 JA |
409 | } |
410 | ||
411 | static struct blk_mq_tags *blk_mq_init_bitmap_tags(struct blk_mq_tags *tags, | |
24391c0d | 412 | int node, int alloc_policy) |
4bb659b1 JA |
413 | { |
414 | unsigned int depth = tags->nr_tags - tags->nr_reserved_tags; | |
f4a644db | 415 | bool round_robin = alloc_policy == BLK_TAG_ALLOC_RR; |
4bb659b1 | 416 | |
f4a644db | 417 | if (bt_alloc(&tags->bitmap_tags, depth, round_robin, node)) |
88459642 | 418 | goto free_tags; |
f4a644db OS |
419 | if (bt_alloc(&tags->breserved_tags, tags->nr_reserved_tags, round_robin, |
420 | node)) | |
88459642 | 421 | goto free_bitmap_tags; |
4bb659b1 JA |
422 | |
423 | return tags; | |
88459642 OS |
424 | free_bitmap_tags: |
425 | sbitmap_queue_free(&tags->bitmap_tags); | |
426 | free_tags: | |
4bb659b1 JA |
427 | kfree(tags); |
428 | return NULL; | |
429 | } | |
430 | ||
320ae51f | 431 | struct blk_mq_tags *blk_mq_init_tags(unsigned int total_tags, |
24391c0d SL |
432 | unsigned int reserved_tags, |
433 | int node, int alloc_policy) | |
320ae51f | 434 | { |
320ae51f | 435 | struct blk_mq_tags *tags; |
320ae51f JA |
436 | |
437 | if (total_tags > BLK_MQ_TAG_MAX) { | |
438 | pr_err("blk-mq: tag depth too large\n"); | |
439 | return NULL; | |
440 | } | |
441 | ||
442 | tags = kzalloc_node(sizeof(*tags), GFP_KERNEL, node); | |
443 | if (!tags) | |
444 | return NULL; | |
445 | ||
320ae51f JA |
446 | tags->nr_tags = total_tags; |
447 | tags->nr_reserved_tags = reserved_tags; | |
320ae51f | 448 | |
24391c0d | 449 | return blk_mq_init_bitmap_tags(tags, node, alloc_policy); |
320ae51f JA |
450 | } |
451 | ||
452 | void blk_mq_free_tags(struct blk_mq_tags *tags) | |
453 | { | |
88459642 OS |
454 | sbitmap_queue_free(&tags->bitmap_tags); |
455 | sbitmap_queue_free(&tags->breserved_tags); | |
320ae51f JA |
456 | kfree(tags); |
457 | } | |
458 | ||
70f36b60 JA |
459 | int blk_mq_tag_update_depth(struct blk_mq_hw_ctx *hctx, |
460 | struct blk_mq_tags **tagsptr, unsigned int tdepth, | |
461 | bool can_grow) | |
e3a2b3f9 | 462 | { |
70f36b60 JA |
463 | struct blk_mq_tags *tags = *tagsptr; |
464 | ||
465 | if (tdepth <= tags->nr_reserved_tags) | |
e3a2b3f9 JA |
466 | return -EINVAL; |
467 | ||
468 | /* | |
70f36b60 JA |
469 | * If we are allowed to grow beyond the original size, allocate |
470 | * a new set of tags before freeing the old one. | |
e3a2b3f9 | 471 | */ |
70f36b60 JA |
472 | if (tdepth > tags->nr_tags) { |
473 | struct blk_mq_tag_set *set = hctx->queue->tag_set; | |
474 | struct blk_mq_tags *new; | |
475 | bool ret; | |
476 | ||
477 | if (!can_grow) | |
478 | return -EINVAL; | |
479 | ||
480 | /* | |
481 | * We need some sort of upper limit, set it high enough that | |
482 | * no valid use cases should require more. | |
483 | */ | |
484 | if (tdepth > 16 * BLKDEV_MAX_RQ) | |
485 | return -EINVAL; | |
486 | ||
75d6e175 ML |
487 | new = blk_mq_alloc_rq_map(set, hctx->queue_num, tdepth, |
488 | tags->nr_reserved_tags); | |
70f36b60 JA |
489 | if (!new) |
490 | return -ENOMEM; | |
491 | ret = blk_mq_alloc_rqs(set, new, hctx->queue_num, tdepth); | |
492 | if (ret) { | |
493 | blk_mq_free_rq_map(new); | |
494 | return -ENOMEM; | |
495 | } | |
496 | ||
497 | blk_mq_free_rqs(set, *tagsptr, hctx->queue_num); | |
498 | blk_mq_free_rq_map(*tagsptr); | |
499 | *tagsptr = new; | |
500 | } else { | |
501 | /* | |
502 | * Don't need (or can't) update reserved tags here, they | |
503 | * remain static and should never need resizing. | |
504 | */ | |
75d6e175 ML |
505 | sbitmap_queue_resize(&tags->bitmap_tags, |
506 | tdepth - tags->nr_reserved_tags); | |
70f36b60 | 507 | } |
88459642 | 508 | |
e3a2b3f9 JA |
509 | return 0; |
510 | } | |
511 | ||
205fb5f5 BVA |
512 | /** |
513 | * blk_mq_unique_tag() - return a tag that is unique queue-wide | |
514 | * @rq: request for which to compute a unique tag | |
515 | * | |
516 | * The tag field in struct request is unique per hardware queue but not over | |
517 | * all hardware queues. Hence this function that returns a tag with the | |
518 | * hardware context index in the upper bits and the per hardware queue tag in | |
519 | * the lower bits. | |
520 | * | |
521 | * Note: When called for a request that is queued on a non-multiqueue request | |
522 | * queue, the hardware context index is set to zero. | |
523 | */ | |
524 | u32 blk_mq_unique_tag(struct request *rq) | |
525 | { | |
ea4f995e | 526 | return (rq->mq_hctx->queue_num << BLK_MQ_UNIQUE_TAG_BITS) | |
205fb5f5 BVA |
527 | (rq->tag & BLK_MQ_UNIQUE_TAG_MASK); |
528 | } | |
529 | EXPORT_SYMBOL(blk_mq_unique_tag); |