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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> | |
f9934a80 | 13 | #include <linux/delay.h> |
320ae51f JA |
14 | #include "blk.h" |
15 | #include "blk-mq.h" | |
16 | #include "blk-mq-tag.h" | |
17 | ||
0d2602ca JA |
18 | /* |
19 | * If a previously inactive queue goes active, bump the active user count. | |
d263ed99 JW |
20 | * We need to do this before try to allocate driver tag, then even if fail |
21 | * to get tag when first time, the other shared-tag users could reserve | |
22 | * budget for it. | |
0d2602ca JA |
23 | */ |
24 | bool __blk_mq_tag_busy(struct blk_mq_hw_ctx *hctx) | |
25 | { | |
26 | if (!test_bit(BLK_MQ_S_TAG_ACTIVE, &hctx->state) && | |
27 | !test_and_set_bit(BLK_MQ_S_TAG_ACTIVE, &hctx->state)) | |
28 | atomic_inc(&hctx->tags->active_queues); | |
29 | ||
30 | return true; | |
31 | } | |
32 | ||
33 | /* | |
aed3ea94 | 34 | * Wakeup all potentially sleeping on tags |
0d2602ca | 35 | */ |
aed3ea94 | 36 | void blk_mq_tag_wakeup_all(struct blk_mq_tags *tags, bool include_reserve) |
0d2602ca | 37 | { |
88459642 OS |
38 | sbitmap_queue_wake_all(&tags->bitmap_tags); |
39 | if (include_reserve) | |
40 | sbitmap_queue_wake_all(&tags->breserved_tags); | |
0d2602ca JA |
41 | } |
42 | ||
e3a2b3f9 JA |
43 | /* |
44 | * If a previously busy queue goes inactive, potential waiters could now | |
45 | * be allowed to queue. Wake them up and check. | |
46 | */ | |
47 | void __blk_mq_tag_idle(struct blk_mq_hw_ctx *hctx) | |
48 | { | |
49 | struct blk_mq_tags *tags = hctx->tags; | |
50 | ||
51 | if (!test_and_clear_bit(BLK_MQ_S_TAG_ACTIVE, &hctx->state)) | |
52 | return; | |
53 | ||
54 | atomic_dec(&tags->active_queues); | |
55 | ||
aed3ea94 | 56 | blk_mq_tag_wakeup_all(tags, false); |
e3a2b3f9 JA |
57 | } |
58 | ||
200e86b3 JA |
59 | static int __blk_mq_get_tag(struct blk_mq_alloc_data *data, |
60 | struct sbitmap_queue *bt) | |
4bb659b1 | 61 | { |
42fdc5e4 | 62 | if (!data->q->elevator && !hctx_may_queue(data->hctx, bt)) |
76647368 | 63 | return BLK_MQ_NO_TAG; |
42fdc5e4 | 64 | |
229a9287 OS |
65 | if (data->shallow_depth) |
66 | return __sbitmap_queue_get_shallow(bt, data->shallow_depth); | |
67 | else | |
68 | return __sbitmap_queue_get(bt); | |
4bb659b1 JA |
69 | } |
70 | ||
4941115b | 71 | unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data) |
320ae51f | 72 | { |
4941115b JA |
73 | struct blk_mq_tags *tags = blk_mq_tags_from_data(data); |
74 | struct sbitmap_queue *bt; | |
88459642 | 75 | struct sbq_wait_state *ws; |
5d2ee712 | 76 | DEFINE_SBQ_WAIT(wait); |
4941115b | 77 | unsigned int tag_offset; |
320ae51f JA |
78 | int tag; |
79 | ||
4941115b JA |
80 | if (data->flags & BLK_MQ_REQ_RESERVED) { |
81 | if (unlikely(!tags->nr_reserved_tags)) { | |
82 | WARN_ON_ONCE(1); | |
419c3d5e | 83 | return BLK_MQ_NO_TAG; |
4941115b JA |
84 | } |
85 | bt = &tags->breserved_tags; | |
86 | tag_offset = 0; | |
87 | } else { | |
88 | bt = &tags->bitmap_tags; | |
89 | tag_offset = tags->nr_reserved_tags; | |
90 | } | |
91 | ||
200e86b3 | 92 | tag = __blk_mq_get_tag(data, bt); |
76647368 | 93 | if (tag != BLK_MQ_NO_TAG) |
4941115b | 94 | goto found_tag; |
4bb659b1 | 95 | |
6f3b0e8b | 96 | if (data->flags & BLK_MQ_REQ_NOWAIT) |
419c3d5e | 97 | return BLK_MQ_NO_TAG; |
4bb659b1 | 98 | |
4941115b | 99 | ws = bt_wait_ptr(bt, data->hctx); |
4bb659b1 | 100 | do { |
e6fc4649 ML |
101 | struct sbitmap_queue *bt_prev; |
102 | ||
b3223207 BVA |
103 | /* |
104 | * We're out of tags on this hardware queue, kick any | |
105 | * pending IO submits before going to sleep waiting for | |
8cecb07d | 106 | * some to complete. |
b3223207 | 107 | */ |
8cecb07d | 108 | blk_mq_run_hw_queue(data->hctx, false); |
b3223207 | 109 | |
080ff351 JA |
110 | /* |
111 | * Retry tag allocation after running the hardware queue, | |
112 | * as running the queue may also have found completions. | |
113 | */ | |
200e86b3 | 114 | tag = __blk_mq_get_tag(data, bt); |
76647368 | 115 | if (tag != BLK_MQ_NO_TAG) |
080ff351 JA |
116 | break; |
117 | ||
5d2ee712 | 118 | sbitmap_prepare_to_wait(bt, ws, &wait, TASK_UNINTERRUPTIBLE); |
4e5dff41 JA |
119 | |
120 | tag = __blk_mq_get_tag(data, bt); | |
76647368 | 121 | if (tag != BLK_MQ_NO_TAG) |
4e5dff41 JA |
122 | break; |
123 | ||
e6fc4649 | 124 | bt_prev = bt; |
4bb659b1 | 125 | io_schedule(); |
cb96a42c | 126 | |
5d2ee712 JA |
127 | sbitmap_finish_wait(bt, ws, &wait); |
128 | ||
cb96a42c | 129 | data->ctx = blk_mq_get_ctx(data->q); |
f9afca4d | 130 | data->hctx = blk_mq_map_queue(data->q, data->cmd_flags, |
8ccdf4a3 | 131 | data->ctx); |
4941115b JA |
132 | tags = blk_mq_tags_from_data(data); |
133 | if (data->flags & BLK_MQ_REQ_RESERVED) | |
134 | bt = &tags->breserved_tags; | |
135 | else | |
136 | bt = &tags->bitmap_tags; | |
137 | ||
e6fc4649 ML |
138 | /* |
139 | * If destination hw queue is changed, fake wake up on | |
140 | * previous queue for compensating the wake up miss, so | |
141 | * other allocations on previous queue won't be starved. | |
142 | */ | |
143 | if (bt != bt_prev) | |
144 | sbitmap_queue_wake_up(bt_prev); | |
145 | ||
4941115b | 146 | ws = bt_wait_ptr(bt, data->hctx); |
4bb659b1 JA |
147 | } while (1); |
148 | ||
5d2ee712 | 149 | sbitmap_finish_wait(bt, ws, &wait); |
320ae51f | 150 | |
4941115b | 151 | found_tag: |
bf0beec0 ML |
152 | /* |
153 | * Give up this allocation if the hctx is inactive. The caller will | |
154 | * retry on an active hctx. | |
155 | */ | |
156 | if (unlikely(test_bit(BLK_MQ_S_INACTIVE, &data->hctx->state))) { | |
157 | blk_mq_put_tag(tags, data->ctx, tag + tag_offset); | |
158 | return BLK_MQ_NO_TAG; | |
159 | } | |
4941115b | 160 | return tag + tag_offset; |
320ae51f JA |
161 | } |
162 | ||
cae740a0 JG |
163 | void blk_mq_put_tag(struct blk_mq_tags *tags, struct blk_mq_ctx *ctx, |
164 | unsigned int tag) | |
320ae51f | 165 | { |
415b806d | 166 | if (!blk_mq_tag_is_reserved(tags, tag)) { |
4bb659b1 JA |
167 | const int real_tag = tag - tags->nr_reserved_tags; |
168 | ||
70114c39 | 169 | BUG_ON(real_tag >= tags->nr_tags); |
f4a644db | 170 | sbitmap_queue_clear(&tags->bitmap_tags, real_tag, ctx->cpu); |
70114c39 JA |
171 | } else { |
172 | BUG_ON(tag >= tags->nr_reserved_tags); | |
f4a644db | 173 | sbitmap_queue_clear(&tags->breserved_tags, tag, ctx->cpu); |
70114c39 | 174 | } |
320ae51f JA |
175 | } |
176 | ||
88459642 OS |
177 | struct bt_iter_data { |
178 | struct blk_mq_hw_ctx *hctx; | |
179 | busy_iter_fn *fn; | |
180 | void *data; | |
181 | bool reserved; | |
182 | }; | |
183 | ||
184 | static bool bt_iter(struct sbitmap *bitmap, unsigned int bitnr, void *data) | |
320ae51f | 185 | { |
88459642 OS |
186 | struct bt_iter_data *iter_data = data; |
187 | struct blk_mq_hw_ctx *hctx = iter_data->hctx; | |
188 | struct blk_mq_tags *tags = hctx->tags; | |
189 | bool reserved = iter_data->reserved; | |
81481eb4 | 190 | struct request *rq; |
4bb659b1 | 191 | |
88459642 OS |
192 | if (!reserved) |
193 | bitnr += tags->nr_reserved_tags; | |
194 | rq = tags->rqs[bitnr]; | |
4bb659b1 | 195 | |
7f5562d5 JA |
196 | /* |
197 | * We can hit rq == NULL here, because the tagging functions | |
c7b1bf5c | 198 | * test and set the bit before assigning ->rqs[]. |
7f5562d5 JA |
199 | */ |
200 | if (rq && rq->q == hctx->queue) | |
7baa8572 | 201 | return iter_data->fn(hctx, rq, iter_data->data, reserved); |
88459642 OS |
202 | return true; |
203 | } | |
4bb659b1 | 204 | |
c7b1bf5c BVA |
205 | /** |
206 | * bt_for_each - iterate over the requests associated with a hardware queue | |
207 | * @hctx: Hardware queue to examine. | |
208 | * @bt: sbitmap to examine. This is either the breserved_tags member | |
209 | * or the bitmap_tags member of struct blk_mq_tags. | |
210 | * @fn: Pointer to the function that will be called for each request | |
211 | * associated with @hctx that has been assigned a driver tag. | |
212 | * @fn will be called as follows: @fn(@hctx, rq, @data, @reserved) | |
ab11fe5a JA |
213 | * where rq is a pointer to a request. Return true to continue |
214 | * iterating tags, false to stop. | |
c7b1bf5c BVA |
215 | * @data: Will be passed as third argument to @fn. |
216 | * @reserved: Indicates whether @bt is the breserved_tags member or the | |
217 | * bitmap_tags member of struct blk_mq_tags. | |
218 | */ | |
88459642 OS |
219 | static void bt_for_each(struct blk_mq_hw_ctx *hctx, struct sbitmap_queue *bt, |
220 | busy_iter_fn *fn, void *data, bool reserved) | |
221 | { | |
222 | struct bt_iter_data iter_data = { | |
223 | .hctx = hctx, | |
224 | .fn = fn, | |
225 | .data = data, | |
226 | .reserved = reserved, | |
227 | }; | |
228 | ||
229 | sbitmap_for_each_set(&bt->sb, bt_iter, &iter_data); | |
320ae51f JA |
230 | } |
231 | ||
88459642 OS |
232 | struct bt_tags_iter_data { |
233 | struct blk_mq_tags *tags; | |
234 | busy_tag_iter_fn *fn; | |
235 | void *data; | |
602380d2 | 236 | unsigned int flags; |
88459642 OS |
237 | }; |
238 | ||
602380d2 ML |
239 | #define BT_TAG_ITER_RESERVED (1 << 0) |
240 | #define BT_TAG_ITER_STARTED (1 << 1) | |
22f614bc | 241 | #define BT_TAG_ITER_STATIC_RQS (1 << 2) |
602380d2 | 242 | |
88459642 | 243 | static bool bt_tags_iter(struct sbitmap *bitmap, unsigned int bitnr, void *data) |
f26cdc85 | 244 | { |
88459642 OS |
245 | struct bt_tags_iter_data *iter_data = data; |
246 | struct blk_mq_tags *tags = iter_data->tags; | |
602380d2 | 247 | bool reserved = iter_data->flags & BT_TAG_ITER_RESERVED; |
f26cdc85 | 248 | struct request *rq; |
f26cdc85 | 249 | |
88459642 OS |
250 | if (!reserved) |
251 | bitnr += tags->nr_reserved_tags; | |
7f5562d5 JA |
252 | |
253 | /* | |
254 | * We can hit rq == NULL here, because the tagging functions | |
22f614bc | 255 | * test and set the bit before assigning ->rqs[]. |
7f5562d5 | 256 | */ |
22f614bc ML |
257 | if (iter_data->flags & BT_TAG_ITER_STATIC_RQS) |
258 | rq = tags->static_rqs[bitnr]; | |
259 | else | |
260 | rq = tags->rqs[bitnr]; | |
602380d2 ML |
261 | if (!rq) |
262 | return true; | |
263 | if ((iter_data->flags & BT_TAG_ITER_STARTED) && | |
264 | !blk_mq_request_started(rq)) | |
265 | return true; | |
266 | return iter_data->fn(rq, iter_data->data, reserved); | |
88459642 OS |
267 | } |
268 | ||
c7b1bf5c BVA |
269 | /** |
270 | * bt_tags_for_each - iterate over the requests in a tag map | |
271 | * @tags: Tag map to iterate over. | |
272 | * @bt: sbitmap to examine. This is either the breserved_tags member | |
273 | * or the bitmap_tags member of struct blk_mq_tags. | |
274 | * @fn: Pointer to the function that will be called for each started | |
275 | * request. @fn will be called as follows: @fn(rq, @data, | |
ab11fe5a JA |
276 | * @reserved) where rq is a pointer to a request. Return true |
277 | * to continue iterating tags, false to stop. | |
c7b1bf5c | 278 | * @data: Will be passed as second argument to @fn. |
602380d2 | 279 | * @flags: BT_TAG_ITER_* |
c7b1bf5c | 280 | */ |
88459642 | 281 | static void bt_tags_for_each(struct blk_mq_tags *tags, struct sbitmap_queue *bt, |
602380d2 | 282 | busy_tag_iter_fn *fn, void *data, unsigned int flags) |
88459642 OS |
283 | { |
284 | struct bt_tags_iter_data iter_data = { | |
285 | .tags = tags, | |
286 | .fn = fn, | |
287 | .data = data, | |
602380d2 | 288 | .flags = flags, |
88459642 OS |
289 | }; |
290 | ||
291 | if (tags->rqs) | |
292 | sbitmap_for_each_set(&bt->sb, bt_tags_iter, &iter_data); | |
f26cdc85 KB |
293 | } |
294 | ||
602380d2 ML |
295 | static void __blk_mq_all_tag_iter(struct blk_mq_tags *tags, |
296 | busy_tag_iter_fn *fn, void *priv, unsigned int flags) | |
297 | { | |
298 | WARN_ON_ONCE(flags & BT_TAG_ITER_RESERVED); | |
299 | ||
300 | if (tags->nr_reserved_tags) | |
301 | bt_tags_for_each(tags, &tags->breserved_tags, fn, priv, | |
302 | flags | BT_TAG_ITER_RESERVED); | |
303 | bt_tags_for_each(tags, &tags->bitmap_tags, fn, priv, flags); | |
304 | } | |
305 | ||
c7b1bf5c | 306 | /** |
602380d2 | 307 | * blk_mq_all_tag_iter - iterate over all requests in a tag map |
c7b1bf5c | 308 | * @tags: Tag map to iterate over. |
602380d2 | 309 | * @fn: Pointer to the function that will be called for each |
c7b1bf5c BVA |
310 | * request. @fn will be called as follows: @fn(rq, @priv, |
311 | * reserved) where rq is a pointer to a request. 'reserved' | |
ab11fe5a JA |
312 | * indicates whether or not @rq is a reserved request. Return |
313 | * true to continue iterating tags, false to stop. | |
c7b1bf5c | 314 | * @priv: Will be passed as second argument to @fn. |
22f614bc ML |
315 | * |
316 | * Caller has to pass the tag map from which requests are allocated. | |
c7b1bf5c | 317 | */ |
602380d2 ML |
318 | void blk_mq_all_tag_iter(struct blk_mq_tags *tags, busy_tag_iter_fn *fn, |
319 | void *priv) | |
f26cdc85 | 320 | { |
a8a5e383 | 321 | __blk_mq_all_tag_iter(tags, fn, priv, BT_TAG_ITER_STATIC_RQS); |
f26cdc85 | 322 | } |
f26cdc85 | 323 | |
c7b1bf5c BVA |
324 | /** |
325 | * blk_mq_tagset_busy_iter - iterate over all started requests in a tag set | |
326 | * @tagset: Tag set to iterate over. | |
327 | * @fn: Pointer to the function that will be called for each started | |
328 | * request. @fn will be called as follows: @fn(rq, @priv, | |
329 | * reserved) where rq is a pointer to a request. 'reserved' | |
ab11fe5a JA |
330 | * indicates whether or not @rq is a reserved request. Return |
331 | * true to continue iterating tags, false to stop. | |
c7b1bf5c BVA |
332 | * @priv: Will be passed as second argument to @fn. |
333 | */ | |
e0489487 SG |
334 | void blk_mq_tagset_busy_iter(struct blk_mq_tag_set *tagset, |
335 | busy_tag_iter_fn *fn, void *priv) | |
336 | { | |
337 | int i; | |
338 | ||
339 | for (i = 0; i < tagset->nr_hw_queues; i++) { | |
340 | if (tagset->tags && tagset->tags[i]) | |
602380d2 ML |
341 | __blk_mq_all_tag_iter(tagset->tags[i], fn, priv, |
342 | BT_TAG_ITER_STARTED); | |
e0489487 SG |
343 | } |
344 | } | |
345 | EXPORT_SYMBOL(blk_mq_tagset_busy_iter); | |
346 | ||
f9934a80 ML |
347 | static bool blk_mq_tagset_count_completed_rqs(struct request *rq, |
348 | void *data, bool reserved) | |
349 | { | |
350 | unsigned *count = data; | |
351 | ||
352 | if (blk_mq_request_completed(rq)) | |
353 | (*count)++; | |
354 | return true; | |
355 | } | |
356 | ||
357 | /** | |
358 | * blk_mq_tagset_wait_completed_request - wait until all completed req's | |
359 | * complete funtion is run | |
360 | * @tagset: Tag set to drain completed request | |
361 | * | |
362 | * Note: This function has to be run after all IO queues are shutdown | |
363 | */ | |
364 | void blk_mq_tagset_wait_completed_request(struct blk_mq_tag_set *tagset) | |
365 | { | |
366 | while (true) { | |
367 | unsigned count = 0; | |
368 | ||
369 | blk_mq_tagset_busy_iter(tagset, | |
370 | blk_mq_tagset_count_completed_rqs, &count); | |
371 | if (!count) | |
372 | break; | |
373 | msleep(5); | |
374 | } | |
375 | } | |
376 | EXPORT_SYMBOL(blk_mq_tagset_wait_completed_request); | |
377 | ||
c7b1bf5c BVA |
378 | /** |
379 | * blk_mq_queue_tag_busy_iter - iterate over all requests with a driver tag | |
380 | * @q: Request queue to examine. | |
381 | * @fn: Pointer to the function that will be called for each request | |
382 | * on @q. @fn will be called as follows: @fn(hctx, rq, @priv, | |
383 | * reserved) where rq is a pointer to a request and hctx points | |
384 | * to the hardware queue associated with the request. 'reserved' | |
385 | * indicates whether or not @rq is a reserved request. | |
386 | * @priv: Will be passed as third argument to @fn. | |
387 | * | |
388 | * Note: if @q->tag_set is shared with other request queues then @fn will be | |
389 | * called for all requests on all queues that share that tag set and not only | |
390 | * for requests associated with @q. | |
391 | */ | |
0bf6cd5b | 392 | void blk_mq_queue_tag_busy_iter(struct request_queue *q, busy_iter_fn *fn, |
81481eb4 | 393 | void *priv) |
320ae51f | 394 | { |
0bf6cd5b CH |
395 | struct blk_mq_hw_ctx *hctx; |
396 | int i; | |
397 | ||
f5bbbbe4 | 398 | /* |
c7b1bf5c BVA |
399 | * __blk_mq_update_nr_hw_queues() updates nr_hw_queues and queue_hw_ctx |
400 | * while the queue is frozen. So we can use q_usage_counter to avoid | |
401 | * racing with it. __blk_mq_update_nr_hw_queues() uses | |
402 | * synchronize_rcu() to ensure this function left the critical section | |
403 | * below. | |
f5bbbbe4 | 404 | */ |
530ca2c9 | 405 | if (!percpu_ref_tryget(&q->q_usage_counter)) |
f5bbbbe4 | 406 | return; |
0bf6cd5b CH |
407 | |
408 | queue_for_each_hw_ctx(q, hctx, i) { | |
409 | struct blk_mq_tags *tags = hctx->tags; | |
410 | ||
411 | /* | |
c7b1bf5c | 412 | * If no software queues are currently mapped to this |
0bf6cd5b CH |
413 | * hardware queue, there's nothing to check |
414 | */ | |
415 | if (!blk_mq_hw_queue_mapped(hctx)) | |
416 | continue; | |
417 | ||
418 | if (tags->nr_reserved_tags) | |
88459642 OS |
419 | bt_for_each(hctx, &tags->breserved_tags, fn, priv, true); |
420 | bt_for_each(hctx, &tags->bitmap_tags, fn, priv, false); | |
4bb659b1 | 421 | } |
530ca2c9 | 422 | blk_queue_exit(q); |
4bb659b1 JA |
423 | } |
424 | ||
f4a644db OS |
425 | static int bt_alloc(struct sbitmap_queue *bt, unsigned int depth, |
426 | bool round_robin, int node) | |
4bb659b1 | 427 | { |
f4a644db OS |
428 | return sbitmap_queue_init_node(bt, depth, -1, round_robin, GFP_KERNEL, |
429 | node); | |
4bb659b1 JA |
430 | } |
431 | ||
432 | static struct blk_mq_tags *blk_mq_init_bitmap_tags(struct blk_mq_tags *tags, | |
24391c0d | 433 | int node, int alloc_policy) |
4bb659b1 JA |
434 | { |
435 | unsigned int depth = tags->nr_tags - tags->nr_reserved_tags; | |
f4a644db | 436 | bool round_robin = alloc_policy == BLK_TAG_ALLOC_RR; |
4bb659b1 | 437 | |
f4a644db | 438 | if (bt_alloc(&tags->bitmap_tags, depth, round_robin, node)) |
88459642 | 439 | goto free_tags; |
f4a644db OS |
440 | if (bt_alloc(&tags->breserved_tags, tags->nr_reserved_tags, round_robin, |
441 | node)) | |
88459642 | 442 | goto free_bitmap_tags; |
4bb659b1 JA |
443 | |
444 | return tags; | |
88459642 OS |
445 | free_bitmap_tags: |
446 | sbitmap_queue_free(&tags->bitmap_tags); | |
447 | free_tags: | |
4bb659b1 JA |
448 | kfree(tags); |
449 | return NULL; | |
450 | } | |
451 | ||
320ae51f | 452 | struct blk_mq_tags *blk_mq_init_tags(unsigned int total_tags, |
24391c0d SL |
453 | unsigned int reserved_tags, |
454 | int node, int alloc_policy) | |
320ae51f | 455 | { |
320ae51f | 456 | struct blk_mq_tags *tags; |
320ae51f JA |
457 | |
458 | if (total_tags > BLK_MQ_TAG_MAX) { | |
459 | pr_err("blk-mq: tag depth too large\n"); | |
460 | return NULL; | |
461 | } | |
462 | ||
463 | tags = kzalloc_node(sizeof(*tags), GFP_KERNEL, node); | |
464 | if (!tags) | |
465 | return NULL; | |
466 | ||
320ae51f JA |
467 | tags->nr_tags = total_tags; |
468 | tags->nr_reserved_tags = reserved_tags; | |
320ae51f | 469 | |
24391c0d | 470 | return blk_mq_init_bitmap_tags(tags, node, alloc_policy); |
320ae51f JA |
471 | } |
472 | ||
473 | void blk_mq_free_tags(struct blk_mq_tags *tags) | |
474 | { | |
88459642 OS |
475 | sbitmap_queue_free(&tags->bitmap_tags); |
476 | sbitmap_queue_free(&tags->breserved_tags); | |
320ae51f JA |
477 | kfree(tags); |
478 | } | |
479 | ||
70f36b60 JA |
480 | int blk_mq_tag_update_depth(struct blk_mq_hw_ctx *hctx, |
481 | struct blk_mq_tags **tagsptr, unsigned int tdepth, | |
482 | bool can_grow) | |
e3a2b3f9 | 483 | { |
70f36b60 JA |
484 | struct blk_mq_tags *tags = *tagsptr; |
485 | ||
486 | if (tdepth <= tags->nr_reserved_tags) | |
e3a2b3f9 JA |
487 | return -EINVAL; |
488 | ||
489 | /* | |
70f36b60 JA |
490 | * If we are allowed to grow beyond the original size, allocate |
491 | * a new set of tags before freeing the old one. | |
e3a2b3f9 | 492 | */ |
70f36b60 JA |
493 | if (tdepth > tags->nr_tags) { |
494 | struct blk_mq_tag_set *set = hctx->queue->tag_set; | |
495 | struct blk_mq_tags *new; | |
496 | bool ret; | |
497 | ||
498 | if (!can_grow) | |
499 | return -EINVAL; | |
500 | ||
501 | /* | |
502 | * We need some sort of upper limit, set it high enough that | |
503 | * no valid use cases should require more. | |
504 | */ | |
505 | if (tdepth > 16 * BLKDEV_MAX_RQ) | |
506 | return -EINVAL; | |
507 | ||
75d6e175 ML |
508 | new = blk_mq_alloc_rq_map(set, hctx->queue_num, tdepth, |
509 | tags->nr_reserved_tags); | |
70f36b60 JA |
510 | if (!new) |
511 | return -ENOMEM; | |
512 | ret = blk_mq_alloc_rqs(set, new, hctx->queue_num, tdepth); | |
513 | if (ret) { | |
514 | blk_mq_free_rq_map(new); | |
515 | return -ENOMEM; | |
516 | } | |
517 | ||
518 | blk_mq_free_rqs(set, *tagsptr, hctx->queue_num); | |
519 | blk_mq_free_rq_map(*tagsptr); | |
520 | *tagsptr = new; | |
521 | } else { | |
522 | /* | |
523 | * Don't need (or can't) update reserved tags here, they | |
524 | * remain static and should never need resizing. | |
525 | */ | |
75d6e175 ML |
526 | sbitmap_queue_resize(&tags->bitmap_tags, |
527 | tdepth - tags->nr_reserved_tags); | |
70f36b60 | 528 | } |
88459642 | 529 | |
e3a2b3f9 JA |
530 | return 0; |
531 | } | |
532 | ||
205fb5f5 BVA |
533 | /** |
534 | * blk_mq_unique_tag() - return a tag that is unique queue-wide | |
535 | * @rq: request for which to compute a unique tag | |
536 | * | |
537 | * The tag field in struct request is unique per hardware queue but not over | |
538 | * all hardware queues. Hence this function that returns a tag with the | |
539 | * hardware context index in the upper bits and the per hardware queue tag in | |
540 | * the lower bits. | |
541 | * | |
542 | * Note: When called for a request that is queued on a non-multiqueue request | |
543 | * queue, the hardware context index is set to zero. | |
544 | */ | |
545 | u32 blk_mq_unique_tag(struct request *rq) | |
546 | { | |
ea4f995e | 547 | return (rq->mq_hctx->queue_num << BLK_MQ_UNIQUE_TAG_BITS) | |
205fb5f5 BVA |
548 | (rq->tag & BLK_MQ_UNIQUE_TAG_MASK); |
549 | } | |
550 | EXPORT_SYMBOL(blk_mq_unique_tag); |