Commit | Line | Data |
---|---|---|
75bb4625 | 1 | /* |
88459642 OS |
2 | * Tag allocation using scalable bitmaps. Uses active queue tracking to support |
3 | * fairer distribution of tags between multiple submitters when a shared tag map | |
4 | * is used. | |
75bb4625 JA |
5 | * |
6 | * Copyright (C) 2013-2014 Jens Axboe | |
7 | */ | |
320ae51f JA |
8 | #include <linux/kernel.h> |
9 | #include <linux/module.h> | |
320ae51f JA |
10 | |
11 | #include <linux/blk-mq.h> | |
12 | #include "blk.h" | |
13 | #include "blk-mq.h" | |
14 | #include "blk-mq-tag.h" | |
15 | ||
320ae51f JA |
16 | bool blk_mq_has_free_tags(struct blk_mq_tags *tags) |
17 | { | |
4bb659b1 JA |
18 | if (!tags) |
19 | return true; | |
20 | ||
88459642 | 21 | return sbitmap_any_bit_clear(&tags->bitmap_tags.sb); |
0d2602ca JA |
22 | } |
23 | ||
24 | /* | |
25 | * If a previously inactive queue goes active, bump the active user count. | |
d263ed99 JW |
26 | * We need to do this before try to allocate driver tag, then even if fail |
27 | * to get tag when first time, the other shared-tag users could reserve | |
28 | * budget for it. | |
0d2602ca JA |
29 | */ |
30 | bool __blk_mq_tag_busy(struct blk_mq_hw_ctx *hctx) | |
31 | { | |
32 | if (!test_bit(BLK_MQ_S_TAG_ACTIVE, &hctx->state) && | |
33 | !test_and_set_bit(BLK_MQ_S_TAG_ACTIVE, &hctx->state)) | |
34 | atomic_inc(&hctx->tags->active_queues); | |
35 | ||
36 | return true; | |
37 | } | |
38 | ||
39 | /* | |
aed3ea94 | 40 | * Wakeup all potentially sleeping on tags |
0d2602ca | 41 | */ |
aed3ea94 | 42 | void blk_mq_tag_wakeup_all(struct blk_mq_tags *tags, bool include_reserve) |
0d2602ca | 43 | { |
88459642 OS |
44 | sbitmap_queue_wake_all(&tags->bitmap_tags); |
45 | if (include_reserve) | |
46 | sbitmap_queue_wake_all(&tags->breserved_tags); | |
0d2602ca JA |
47 | } |
48 | ||
e3a2b3f9 JA |
49 | /* |
50 | * If a previously busy queue goes inactive, potential waiters could now | |
51 | * be allowed to queue. Wake them up and check. | |
52 | */ | |
53 | void __blk_mq_tag_idle(struct blk_mq_hw_ctx *hctx) | |
54 | { | |
55 | struct blk_mq_tags *tags = hctx->tags; | |
56 | ||
57 | if (!test_and_clear_bit(BLK_MQ_S_TAG_ACTIVE, &hctx->state)) | |
58 | return; | |
59 | ||
60 | atomic_dec(&tags->active_queues); | |
61 | ||
aed3ea94 | 62 | blk_mq_tag_wakeup_all(tags, false); |
e3a2b3f9 JA |
63 | } |
64 | ||
0d2602ca JA |
65 | /* |
66 | * For shared tag users, we track the number of currently active users | |
67 | * and attempt to provide a fair share of the tag depth for each of them. | |
68 | */ | |
69 | static inline bool hctx_may_queue(struct blk_mq_hw_ctx *hctx, | |
88459642 | 70 | struct sbitmap_queue *bt) |
0d2602ca JA |
71 | { |
72 | unsigned int depth, users; | |
73 | ||
74 | if (!hctx || !(hctx->flags & BLK_MQ_F_TAG_SHARED)) | |
75 | return true; | |
76 | if (!test_bit(BLK_MQ_S_TAG_ACTIVE, &hctx->state)) | |
77 | return true; | |
78 | ||
79 | /* | |
80 | * Don't try dividing an ant | |
81 | */ | |
88459642 | 82 | if (bt->sb.depth == 1) |
0d2602ca JA |
83 | return true; |
84 | ||
85 | users = atomic_read(&hctx->tags->active_queues); | |
86 | if (!users) | |
87 | return true; | |
88 | ||
89 | /* | |
90 | * Allow at least some tags | |
91 | */ | |
88459642 | 92 | depth = max((bt->sb.depth + users - 1) / users, 4U); |
0d2602ca JA |
93 | return atomic_read(&hctx->nr_active) < depth; |
94 | } | |
95 | ||
200e86b3 JA |
96 | static int __blk_mq_get_tag(struct blk_mq_alloc_data *data, |
97 | struct sbitmap_queue *bt) | |
4bb659b1 | 98 | { |
200e86b3 JA |
99 | if (!(data->flags & BLK_MQ_REQ_INTERNAL) && |
100 | !hctx_may_queue(data->hctx, bt)) | |
0d2602ca | 101 | return -1; |
229a9287 OS |
102 | if (data->shallow_depth) |
103 | return __sbitmap_queue_get_shallow(bt, data->shallow_depth); | |
104 | else | |
105 | return __sbitmap_queue_get(bt); | |
4bb659b1 JA |
106 | } |
107 | ||
4941115b | 108 | unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data) |
320ae51f | 109 | { |
4941115b JA |
110 | struct blk_mq_tags *tags = blk_mq_tags_from_data(data); |
111 | struct sbitmap_queue *bt; | |
88459642 | 112 | struct sbq_wait_state *ws; |
4bb659b1 | 113 | DEFINE_WAIT(wait); |
4941115b | 114 | unsigned int tag_offset; |
bd6737f1 | 115 | bool drop_ctx; |
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); |
bd6737f1 | 138 | drop_ctx = data->ctx == NULL; |
4bb659b1 | 139 | do { |
e6fc4649 ML |
140 | struct sbitmap_queue *bt_prev; |
141 | ||
b3223207 BVA |
142 | /* |
143 | * We're out of tags on this hardware queue, kick any | |
144 | * pending IO submits before going to sleep waiting for | |
8cecb07d | 145 | * some to complete. |
b3223207 | 146 | */ |
8cecb07d | 147 | blk_mq_run_hw_queue(data->hctx, false); |
b3223207 | 148 | |
080ff351 JA |
149 | /* |
150 | * Retry tag allocation after running the hardware queue, | |
151 | * as running the queue may also have found completions. | |
152 | */ | |
200e86b3 | 153 | tag = __blk_mq_get_tag(data, bt); |
080ff351 JA |
154 | if (tag != -1) |
155 | break; | |
156 | ||
4e5dff41 JA |
157 | prepare_to_wait_exclusive(&ws->wait, &wait, |
158 | TASK_UNINTERRUPTIBLE); | |
159 | ||
160 | tag = __blk_mq_get_tag(data, bt); | |
161 | if (tag != -1) | |
162 | break; | |
163 | ||
bd6737f1 JA |
164 | if (data->ctx) |
165 | blk_mq_put_ctx(data->ctx); | |
cb96a42c | 166 | |
e6fc4649 | 167 | bt_prev = bt; |
4bb659b1 | 168 | io_schedule(); |
cb96a42c ML |
169 | |
170 | data->ctx = blk_mq_get_ctx(data->q); | |
7d7e0f90 | 171 | data->hctx = blk_mq_map_queue(data->q, data->ctx->cpu); |
4941115b JA |
172 | tags = blk_mq_tags_from_data(data); |
173 | if (data->flags & BLK_MQ_REQ_RESERVED) | |
174 | bt = &tags->breserved_tags; | |
175 | else | |
176 | bt = &tags->bitmap_tags; | |
177 | ||
88459642 | 178 | finish_wait(&ws->wait, &wait); |
e6fc4649 ML |
179 | |
180 | /* | |
181 | * If destination hw queue is changed, fake wake up on | |
182 | * previous queue for compensating the wake up miss, so | |
183 | * other allocations on previous queue won't be starved. | |
184 | */ | |
185 | if (bt != bt_prev) | |
186 | sbitmap_queue_wake_up(bt_prev); | |
187 | ||
4941115b | 188 | ws = bt_wait_ptr(bt, data->hctx); |
4bb659b1 JA |
189 | } while (1); |
190 | ||
bd6737f1 JA |
191 | if (drop_ctx && data->ctx) |
192 | blk_mq_put_ctx(data->ctx); | |
193 | ||
88459642 | 194 | finish_wait(&ws->wait, &wait); |
320ae51f | 195 | |
4941115b JA |
196 | found_tag: |
197 | return tag + tag_offset; | |
320ae51f JA |
198 | } |
199 | ||
4941115b JA |
200 | void blk_mq_put_tag(struct blk_mq_hw_ctx *hctx, struct blk_mq_tags *tags, |
201 | struct blk_mq_ctx *ctx, unsigned int tag) | |
320ae51f | 202 | { |
415b806d | 203 | if (!blk_mq_tag_is_reserved(tags, tag)) { |
4bb659b1 JA |
204 | const int real_tag = tag - tags->nr_reserved_tags; |
205 | ||
70114c39 | 206 | BUG_ON(real_tag >= tags->nr_tags); |
f4a644db | 207 | sbitmap_queue_clear(&tags->bitmap_tags, real_tag, ctx->cpu); |
70114c39 JA |
208 | } else { |
209 | BUG_ON(tag >= tags->nr_reserved_tags); | |
f4a644db | 210 | sbitmap_queue_clear(&tags->breserved_tags, tag, ctx->cpu); |
70114c39 | 211 | } |
320ae51f JA |
212 | } |
213 | ||
88459642 OS |
214 | struct bt_iter_data { |
215 | struct blk_mq_hw_ctx *hctx; | |
216 | busy_iter_fn *fn; | |
217 | void *data; | |
218 | bool reserved; | |
219 | }; | |
220 | ||
221 | static bool bt_iter(struct sbitmap *bitmap, unsigned int bitnr, void *data) | |
320ae51f | 222 | { |
88459642 OS |
223 | struct bt_iter_data *iter_data = data; |
224 | struct blk_mq_hw_ctx *hctx = iter_data->hctx; | |
225 | struct blk_mq_tags *tags = hctx->tags; | |
226 | bool reserved = iter_data->reserved; | |
81481eb4 | 227 | struct request *rq; |
4bb659b1 | 228 | |
88459642 OS |
229 | if (!reserved) |
230 | bitnr += tags->nr_reserved_tags; | |
231 | rq = tags->rqs[bitnr]; | |
4bb659b1 | 232 | |
7f5562d5 JA |
233 | /* |
234 | * We can hit rq == NULL here, because the tagging functions | |
c7b1bf5c | 235 | * test and set the bit before assigning ->rqs[]. |
7f5562d5 JA |
236 | */ |
237 | if (rq && rq->q == hctx->queue) | |
88459642 OS |
238 | iter_data->fn(hctx, rq, iter_data->data, reserved); |
239 | return true; | |
240 | } | |
4bb659b1 | 241 | |
c7b1bf5c BVA |
242 | /** |
243 | * bt_for_each - iterate over the requests associated with a hardware queue | |
244 | * @hctx: Hardware queue to examine. | |
245 | * @bt: sbitmap to examine. This is either the breserved_tags member | |
246 | * or the bitmap_tags member of struct blk_mq_tags. | |
247 | * @fn: Pointer to the function that will be called for each request | |
248 | * associated with @hctx that has been assigned a driver tag. | |
249 | * @fn will be called as follows: @fn(@hctx, rq, @data, @reserved) | |
250 | * where rq is a pointer to a request. | |
251 | * @data: Will be passed as third argument to @fn. | |
252 | * @reserved: Indicates whether @bt is the breserved_tags member or the | |
253 | * bitmap_tags member of struct blk_mq_tags. | |
254 | */ | |
88459642 OS |
255 | static void bt_for_each(struct blk_mq_hw_ctx *hctx, struct sbitmap_queue *bt, |
256 | busy_iter_fn *fn, void *data, bool reserved) | |
257 | { | |
258 | struct bt_iter_data iter_data = { | |
259 | .hctx = hctx, | |
260 | .fn = fn, | |
261 | .data = data, | |
262 | .reserved = reserved, | |
263 | }; | |
264 | ||
265 | sbitmap_for_each_set(&bt->sb, bt_iter, &iter_data); | |
320ae51f JA |
266 | } |
267 | ||
88459642 OS |
268 | struct bt_tags_iter_data { |
269 | struct blk_mq_tags *tags; | |
270 | busy_tag_iter_fn *fn; | |
271 | void *data; | |
272 | bool reserved; | |
273 | }; | |
274 | ||
275 | static bool bt_tags_iter(struct sbitmap *bitmap, unsigned int bitnr, void *data) | |
f26cdc85 | 276 | { |
88459642 OS |
277 | struct bt_tags_iter_data *iter_data = data; |
278 | struct blk_mq_tags *tags = iter_data->tags; | |
279 | bool reserved = iter_data->reserved; | |
f26cdc85 | 280 | struct request *rq; |
f26cdc85 | 281 | |
88459642 OS |
282 | if (!reserved) |
283 | bitnr += tags->nr_reserved_tags; | |
7f5562d5 JA |
284 | |
285 | /* | |
286 | * We can hit rq == NULL here, because the tagging functions | |
287 | * test and set the bit before assining ->rqs[]. | |
288 | */ | |
88459642 | 289 | rq = tags->rqs[bitnr]; |
2d5ba0e2 | 290 | if (rq && blk_mq_request_started(rq)) |
7f5562d5 | 291 | iter_data->fn(rq, iter_data->data, reserved); |
f26cdc85 | 292 | |
88459642 OS |
293 | return true; |
294 | } | |
295 | ||
c7b1bf5c BVA |
296 | /** |
297 | * bt_tags_for_each - iterate over the requests in a tag map | |
298 | * @tags: Tag map to iterate over. | |
299 | * @bt: sbitmap to examine. This is either the breserved_tags member | |
300 | * or the bitmap_tags member of struct blk_mq_tags. | |
301 | * @fn: Pointer to the function that will be called for each started | |
302 | * request. @fn will be called as follows: @fn(rq, @data, | |
303 | * @reserved) where rq is a pointer to a request. | |
304 | * @data: Will be passed as second argument to @fn. | |
305 | * @reserved: Indicates whether @bt is the breserved_tags member or the | |
306 | * bitmap_tags member of struct blk_mq_tags. | |
307 | */ | |
88459642 OS |
308 | static void bt_tags_for_each(struct blk_mq_tags *tags, struct sbitmap_queue *bt, |
309 | busy_tag_iter_fn *fn, void *data, bool reserved) | |
310 | { | |
311 | struct bt_tags_iter_data iter_data = { | |
312 | .tags = tags, | |
313 | .fn = fn, | |
314 | .data = data, | |
315 | .reserved = reserved, | |
316 | }; | |
317 | ||
318 | if (tags->rqs) | |
319 | sbitmap_for_each_set(&bt->sb, bt_tags_iter, &iter_data); | |
f26cdc85 KB |
320 | } |
321 | ||
c7b1bf5c BVA |
322 | /** |
323 | * blk_mq_all_tag_busy_iter - iterate over all started requests in a tag map | |
324 | * @tags: Tag map to iterate over. | |
325 | * @fn: Pointer to the function that will be called for each started | |
326 | * request. @fn will be called as follows: @fn(rq, @priv, | |
327 | * reserved) where rq is a pointer to a request. 'reserved' | |
328 | * indicates whether or not @rq is a reserved request. | |
329 | * @priv: Will be passed as second argument to @fn. | |
330 | */ | |
e8f1e163 SG |
331 | static void blk_mq_all_tag_busy_iter(struct blk_mq_tags *tags, |
332 | busy_tag_iter_fn *fn, void *priv) | |
f26cdc85 KB |
333 | { |
334 | if (tags->nr_reserved_tags) | |
88459642 OS |
335 | bt_tags_for_each(tags, &tags->breserved_tags, fn, priv, true); |
336 | bt_tags_for_each(tags, &tags->bitmap_tags, fn, priv, false); | |
f26cdc85 | 337 | } |
f26cdc85 | 338 | |
c7b1bf5c BVA |
339 | /** |
340 | * blk_mq_tagset_busy_iter - iterate over all started requests in a tag set | |
341 | * @tagset: Tag set to iterate over. | |
342 | * @fn: Pointer to the function that will be called for each started | |
343 | * request. @fn will be called as follows: @fn(rq, @priv, | |
344 | * reserved) where rq is a pointer to a request. 'reserved' | |
345 | * indicates whether or not @rq is a reserved request. | |
346 | * @priv: Will be passed as second argument to @fn. | |
347 | */ | |
e0489487 SG |
348 | void blk_mq_tagset_busy_iter(struct blk_mq_tag_set *tagset, |
349 | busy_tag_iter_fn *fn, void *priv) | |
350 | { | |
351 | int i; | |
352 | ||
353 | for (i = 0; i < tagset->nr_hw_queues; i++) { | |
354 | if (tagset->tags && tagset->tags[i]) | |
355 | blk_mq_all_tag_busy_iter(tagset->tags[i], fn, priv); | |
356 | } | |
357 | } | |
358 | EXPORT_SYMBOL(blk_mq_tagset_busy_iter); | |
359 | ||
c7b1bf5c BVA |
360 | /** |
361 | * blk_mq_queue_tag_busy_iter - iterate over all requests with a driver tag | |
362 | * @q: Request queue to examine. | |
363 | * @fn: Pointer to the function that will be called for each request | |
364 | * on @q. @fn will be called as follows: @fn(hctx, rq, @priv, | |
365 | * reserved) where rq is a pointer to a request and hctx points | |
366 | * to the hardware queue associated with the request. 'reserved' | |
367 | * indicates whether or not @rq is a reserved request. | |
368 | * @priv: Will be passed as third argument to @fn. | |
369 | * | |
370 | * Note: if @q->tag_set is shared with other request queues then @fn will be | |
371 | * called for all requests on all queues that share that tag set and not only | |
372 | * for requests associated with @q. | |
373 | */ | |
0bf6cd5b | 374 | void blk_mq_queue_tag_busy_iter(struct request_queue *q, busy_iter_fn *fn, |
81481eb4 | 375 | void *priv) |
320ae51f | 376 | { |
0bf6cd5b CH |
377 | struct blk_mq_hw_ctx *hctx; |
378 | int i; | |
379 | ||
f5bbbbe4 | 380 | /* |
c7b1bf5c BVA |
381 | * __blk_mq_update_nr_hw_queues() updates nr_hw_queues and queue_hw_ctx |
382 | * while the queue is frozen. So we can use q_usage_counter to avoid | |
383 | * racing with it. __blk_mq_update_nr_hw_queues() uses | |
384 | * synchronize_rcu() to ensure this function left the critical section | |
385 | * below. | |
f5bbbbe4 | 386 | */ |
530ca2c9 | 387 | if (!percpu_ref_tryget(&q->q_usage_counter)) |
f5bbbbe4 | 388 | return; |
0bf6cd5b CH |
389 | |
390 | queue_for_each_hw_ctx(q, hctx, i) { | |
391 | struct blk_mq_tags *tags = hctx->tags; | |
392 | ||
393 | /* | |
c7b1bf5c | 394 | * If no software queues are currently mapped to this |
0bf6cd5b CH |
395 | * hardware queue, there's nothing to check |
396 | */ | |
397 | if (!blk_mq_hw_queue_mapped(hctx)) | |
398 | continue; | |
399 | ||
400 | if (tags->nr_reserved_tags) | |
88459642 OS |
401 | bt_for_each(hctx, &tags->breserved_tags, fn, priv, true); |
402 | bt_for_each(hctx, &tags->bitmap_tags, fn, priv, false); | |
4bb659b1 | 403 | } |
530ca2c9 | 404 | blk_queue_exit(q); |
4bb659b1 JA |
405 | } |
406 | ||
f4a644db OS |
407 | static int bt_alloc(struct sbitmap_queue *bt, unsigned int depth, |
408 | bool round_robin, int node) | |
4bb659b1 | 409 | { |
f4a644db OS |
410 | return sbitmap_queue_init_node(bt, depth, -1, round_robin, GFP_KERNEL, |
411 | node); | |
4bb659b1 JA |
412 | } |
413 | ||
414 | static struct blk_mq_tags *blk_mq_init_bitmap_tags(struct blk_mq_tags *tags, | |
24391c0d | 415 | int node, int alloc_policy) |
4bb659b1 JA |
416 | { |
417 | unsigned int depth = tags->nr_tags - tags->nr_reserved_tags; | |
f4a644db | 418 | bool round_robin = alloc_policy == BLK_TAG_ALLOC_RR; |
4bb659b1 | 419 | |
f4a644db | 420 | if (bt_alloc(&tags->bitmap_tags, depth, round_robin, node)) |
88459642 | 421 | goto free_tags; |
f4a644db OS |
422 | if (bt_alloc(&tags->breserved_tags, tags->nr_reserved_tags, round_robin, |
423 | node)) | |
88459642 | 424 | goto free_bitmap_tags; |
4bb659b1 JA |
425 | |
426 | return tags; | |
88459642 OS |
427 | free_bitmap_tags: |
428 | sbitmap_queue_free(&tags->bitmap_tags); | |
429 | free_tags: | |
4bb659b1 JA |
430 | kfree(tags); |
431 | return NULL; | |
432 | } | |
433 | ||
320ae51f | 434 | struct blk_mq_tags *blk_mq_init_tags(unsigned int total_tags, |
24391c0d SL |
435 | unsigned int reserved_tags, |
436 | int node, int alloc_policy) | |
320ae51f | 437 | { |
320ae51f | 438 | struct blk_mq_tags *tags; |
320ae51f JA |
439 | |
440 | if (total_tags > BLK_MQ_TAG_MAX) { | |
441 | pr_err("blk-mq: tag depth too large\n"); | |
442 | return NULL; | |
443 | } | |
444 | ||
445 | tags = kzalloc_node(sizeof(*tags), GFP_KERNEL, node); | |
446 | if (!tags) | |
447 | return NULL; | |
448 | ||
320ae51f JA |
449 | tags->nr_tags = total_tags; |
450 | tags->nr_reserved_tags = reserved_tags; | |
320ae51f | 451 | |
24391c0d | 452 | return blk_mq_init_bitmap_tags(tags, node, alloc_policy); |
320ae51f JA |
453 | } |
454 | ||
455 | void blk_mq_free_tags(struct blk_mq_tags *tags) | |
456 | { | |
88459642 OS |
457 | sbitmap_queue_free(&tags->bitmap_tags); |
458 | sbitmap_queue_free(&tags->breserved_tags); | |
320ae51f JA |
459 | kfree(tags); |
460 | } | |
461 | ||
70f36b60 JA |
462 | int blk_mq_tag_update_depth(struct blk_mq_hw_ctx *hctx, |
463 | struct blk_mq_tags **tagsptr, unsigned int tdepth, | |
464 | bool can_grow) | |
e3a2b3f9 | 465 | { |
70f36b60 JA |
466 | struct blk_mq_tags *tags = *tagsptr; |
467 | ||
468 | if (tdepth <= tags->nr_reserved_tags) | |
e3a2b3f9 JA |
469 | return -EINVAL; |
470 | ||
471 | /* | |
70f36b60 JA |
472 | * If we are allowed to grow beyond the original size, allocate |
473 | * a new set of tags before freeing the old one. | |
e3a2b3f9 | 474 | */ |
70f36b60 JA |
475 | if (tdepth > tags->nr_tags) { |
476 | struct blk_mq_tag_set *set = hctx->queue->tag_set; | |
477 | struct blk_mq_tags *new; | |
478 | bool ret; | |
479 | ||
480 | if (!can_grow) | |
481 | return -EINVAL; | |
482 | ||
483 | /* | |
484 | * We need some sort of upper limit, set it high enough that | |
485 | * no valid use cases should require more. | |
486 | */ | |
487 | if (tdepth > 16 * BLKDEV_MAX_RQ) | |
488 | return -EINVAL; | |
489 | ||
75d6e175 ML |
490 | new = blk_mq_alloc_rq_map(set, hctx->queue_num, tdepth, |
491 | tags->nr_reserved_tags); | |
70f36b60 JA |
492 | if (!new) |
493 | return -ENOMEM; | |
494 | ret = blk_mq_alloc_rqs(set, new, hctx->queue_num, tdepth); | |
495 | if (ret) { | |
496 | blk_mq_free_rq_map(new); | |
497 | return -ENOMEM; | |
498 | } | |
499 | ||
500 | blk_mq_free_rqs(set, *tagsptr, hctx->queue_num); | |
501 | blk_mq_free_rq_map(*tagsptr); | |
502 | *tagsptr = new; | |
503 | } else { | |
504 | /* | |
505 | * Don't need (or can't) update reserved tags here, they | |
506 | * remain static and should never need resizing. | |
507 | */ | |
75d6e175 ML |
508 | sbitmap_queue_resize(&tags->bitmap_tags, |
509 | tdepth - tags->nr_reserved_tags); | |
70f36b60 | 510 | } |
88459642 | 511 | |
e3a2b3f9 JA |
512 | return 0; |
513 | } | |
514 | ||
205fb5f5 BVA |
515 | /** |
516 | * blk_mq_unique_tag() - return a tag that is unique queue-wide | |
517 | * @rq: request for which to compute a unique tag | |
518 | * | |
519 | * The tag field in struct request is unique per hardware queue but not over | |
520 | * all hardware queues. Hence this function that returns a tag with the | |
521 | * hardware context index in the upper bits and the per hardware queue tag in | |
522 | * the lower bits. | |
523 | * | |
524 | * Note: When called for a request that is queued on a non-multiqueue request | |
525 | * queue, the hardware context index is set to zero. | |
526 | */ | |
527 | u32 blk_mq_unique_tag(struct request *rq) | |
528 | { | |
529 | struct request_queue *q = rq->q; | |
530 | struct blk_mq_hw_ctx *hctx; | |
531 | int hwq = 0; | |
532 | ||
533 | if (q->mq_ops) { | |
7d7e0f90 | 534 | hctx = blk_mq_map_queue(q, rq->mq_ctx->cpu); |
205fb5f5 BVA |
535 | hwq = hctx->queue_num; |
536 | } | |
537 | ||
538 | return (hwq << BLK_MQ_UNIQUE_TAG_BITS) | | |
539 | (rq->tag & BLK_MQ_UNIQUE_TAG_MASK); | |
540 | } | |
541 | EXPORT_SYMBOL(blk_mq_unique_tag); |