projects/linux·blob v5.19-rc7 · refs

819 lines · 19.2 KiB

1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2016 Facebook
4 * Copyright (C) 2013-2014 Jens Axboe
5 */
6
7#include <linux/sched.h>
8#include <linux/random.h>
9#include <linux/sbitmap.h>
10#include <linux/seq_file.h>
11
12static int init_alloc_hint(struct sbitmap *sb, gfp_t flags)
13{
14 unsigned depth = sb->depth;
15
16 sb->alloc_hint = alloc_percpu_gfp(unsigned int, flags);
17 if (!sb->alloc_hint)
18 return -ENOMEM;
19
20 if (depth && !sb->round_robin) {
21 int i;
22
23 for_each_possible_cpu(i)
24 *per_cpu_ptr(sb->alloc_hint, i) = prandom_u32() % depth;
25 }
26 return 0;
27}
28
29static inline unsigned update_alloc_hint_before_get(struct sbitmap *sb,
30 unsigned int depth)
31{
32 unsigned hint;
33
34 hint = this_cpu_read(*sb->alloc_hint);
35 if (unlikely(hint >= depth)) {
36 hint = depth ? prandom_u32() % depth : 0;
37 this_cpu_write(*sb->alloc_hint, hint);
38 }
39
40 return hint;
41}
42
43static inline void update_alloc_hint_after_get(struct sbitmap *sb,
44 unsigned int depth,
45 unsigned int hint,
46 unsigned int nr)
47{
48 if (nr == -1) {
49 /* If the map is full, a hint won't do us much good. */
50 this_cpu_write(*sb->alloc_hint, 0);
51 } else if (nr == hint || unlikely(sb->round_robin)) {
52 /* Only update the hint if we used it. */
53 hint = nr + 1;
54 if (hint >= depth - 1)
55 hint = 0;
56 this_cpu_write(*sb->alloc_hint, hint);
57 }
58}
59
60/*
61 * See if we have deferred clears that we can batch move
62 */
63static inline bool sbitmap_deferred_clear(struct sbitmap_word *map)
64{
65 unsigned long mask;
66
67 if (!READ_ONCE(map->cleared))
68 return false;
69
70 /*
71 * First get a stable cleared mask, setting the old mask to 0.
72 */
73 mask = xchg(&map->cleared, 0);
74
75 /*
76 * Now clear the masked bits in our free word
77 */
78 atomic_long_andnot(mask, (atomic_long_t *)&map->word);
79 BUILD_BUG_ON(sizeof(atomic_long_t) != sizeof(map->word));
80 return true;
81}
82
83int sbitmap_init_node(struct sbitmap *sb, unsigned int depth, int shift,
84 gfp_t flags, int node, bool round_robin,
85 bool alloc_hint)
86{
87 unsigned int bits_per_word;
88
89 if (shift < 0)
90 shift = sbitmap_calculate_shift(depth);
91
92 bits_per_word = 1U << shift;
93 if (bits_per_word > BITS_PER_LONG)
94 return -EINVAL;
95
96 sb->shift = shift;
97 sb->depth = depth;
98 sb->map_nr = DIV_ROUND_UP(sb->depth, bits_per_word);
99 sb->round_robin = round_robin;
100
101 if (depth == 0) {
102 sb->map = NULL;
103 return 0;
104 }
105
106 if (alloc_hint) {
107 if (init_alloc_hint(sb, flags))
108 return -ENOMEM;
109 } else {
110 sb->alloc_hint = NULL;
111 }
112
113 sb->map = kvzalloc_node(sb->map_nr * sizeof(*sb->map), flags, node);
114 if (!sb->map) {
115 free_percpu(sb->alloc_hint);
116 return -ENOMEM;
117 }
118
119 return 0;
120}
121EXPORT_SYMBOL_GPL(sbitmap_init_node);
122
123void sbitmap_resize(struct sbitmap *sb, unsigned int depth)
124{
125 unsigned int bits_per_word = 1U << sb->shift;
126 unsigned int i;
127
128 for (i = 0; i < sb->map_nr; i++)
129 sbitmap_deferred_clear(&sb->map[i]);
130
131 sb->depth = depth;
132 sb->map_nr = DIV_ROUND_UP(sb->depth, bits_per_word);
133}
134EXPORT_SYMBOL_GPL(sbitmap_resize);
135
136static int __sbitmap_get_word(unsigned long *word, unsigned long depth,
137 unsigned int hint, bool wrap)
138{
139 int nr;
140
141 /* don't wrap if starting from 0 */
142 wrap = wrap && hint;
143
144 while (1) {
145 nr = find_next_zero_bit(word, depth, hint);
146 if (unlikely(nr >= depth)) {
147 /*
148 * We started with an offset, and we didn't reset the
149 * offset to 0 in a failure case, so start from 0 to
150 * exhaust the map.
151 */
152 if (hint && wrap) {
153 hint = 0;
154 continue;
155 }
156 return -1;
157 }
158
159 if (!test_and_set_bit_lock(nr, word))
160 break;
161
162 hint = nr + 1;
163 if (hint >= depth - 1)
164 hint = 0;
165 }
166
167 return nr;
168}
169
170static int sbitmap_find_bit_in_index(struct sbitmap *sb, int index,
171 unsigned int alloc_hint)
172{
173 struct sbitmap_word *map = &sb->map[index];
174 int nr;
175
176 do {
177 nr = __sbitmap_get_word(&map->word, __map_depth(sb, index),
178 alloc_hint, !sb->round_robin);
179 if (nr != -1)
180 break;
181 if (!sbitmap_deferred_clear(map))
182 break;
183 } while (1);
184
185 return nr;
186}
187
188static int __sbitmap_get(struct sbitmap *sb, unsigned int alloc_hint)
189{
190 unsigned int i, index;
191 int nr = -1;
192
193 index = SB_NR_TO_INDEX(sb, alloc_hint);
194
195 /*
196 * Unless we're doing round robin tag allocation, just use the
197 * alloc_hint to find the right word index. No point in looping
198 * twice in find_next_zero_bit() for that case.
199 */
200 if (sb->round_robin)
201 alloc_hint = SB_NR_TO_BIT(sb, alloc_hint);
202 else
203 alloc_hint = 0;
204
205 for (i = 0; i < sb->map_nr; i++) {
206 nr = sbitmap_find_bit_in_index(sb, index, alloc_hint);
207 if (nr != -1) {
208 nr += index << sb->shift;
209 break;
210 }
211
212 /* Jump to next index. */
213 alloc_hint = 0;
214 if (++index >= sb->map_nr)
215 index = 0;
216 }
217
218 return nr;
219}
220
221int sbitmap_get(struct sbitmap *sb)
222{
223 int nr;
224 unsigned int hint, depth;
225
226 if (WARN_ON_ONCE(unlikely(!sb->alloc_hint)))
227 return -1;
228
229 depth = READ_ONCE(sb->depth);
230 hint = update_alloc_hint_before_get(sb, depth);
231 nr = __sbitmap_get(sb, hint);
232 update_alloc_hint_after_get(sb, depth, hint, nr);
233
234 return nr;
235}
236EXPORT_SYMBOL_GPL(sbitmap_get);
237
238static int __sbitmap_get_shallow(struct sbitmap *sb,
239 unsigned int alloc_hint,
240 unsigned long shallow_depth)
241{
242 unsigned int i, index;
243 int nr = -1;
244
245 index = SB_NR_TO_INDEX(sb, alloc_hint);
246
247 for (i = 0; i < sb->map_nr; i++) {
248again:
249 nr = __sbitmap_get_word(&sb->map[index].word,
250 min_t(unsigned int,
251 __map_depth(sb, index),
252 shallow_depth),
253 SB_NR_TO_BIT(sb, alloc_hint), true);
254 if (nr != -1) {
255 nr += index << sb->shift;
256 break;
257 }
258
259 if (sbitmap_deferred_clear(&sb->map[index]))
260 goto again;
261
262 /* Jump to next index. */
263 index++;
264 alloc_hint = index << sb->shift;
265
266 if (index >= sb->map_nr) {
267 index = 0;
268 alloc_hint = 0;
269 }
270 }
271
272 return nr;
273}
274
275int sbitmap_get_shallow(struct sbitmap *sb, unsigned long shallow_depth)
276{
277 int nr;
278 unsigned int hint, depth;
279
280 if (WARN_ON_ONCE(unlikely(!sb->alloc_hint)))
281 return -1;
282
283 depth = READ_ONCE(sb->depth);
284 hint = update_alloc_hint_before_get(sb, depth);
285 nr = __sbitmap_get_shallow(sb, hint, shallow_depth);
286 update_alloc_hint_after_get(sb, depth, hint, nr);
287
288 return nr;
289}
290EXPORT_SYMBOL_GPL(sbitmap_get_shallow);
291
292bool sbitmap_any_bit_set(const struct sbitmap *sb)
293{
294 unsigned int i;
295
296 for (i = 0; i < sb->map_nr; i++) {
297 if (sb->map[i].word & ~sb->map[i].cleared)
298 return true;
299 }
300 return false;
301}
302EXPORT_SYMBOL_GPL(sbitmap_any_bit_set);
303
304static unsigned int __sbitmap_weight(const struct sbitmap *sb, bool set)
305{
306 unsigned int i, weight = 0;
307
308 for (i = 0; i < sb->map_nr; i++) {
309 const struct sbitmap_word *word = &sb->map[i];
310 unsigned int word_depth = __map_depth(sb, i);
311
312 if (set)
313 weight += bitmap_weight(&word->word, word_depth);
314 else
315 weight += bitmap_weight(&word->cleared, word_depth);
316 }
317 return weight;
318}
319
320static unsigned int sbitmap_cleared(const struct sbitmap *sb)
321{
322 return __sbitmap_weight(sb, false);
323}
324
325unsigned int sbitmap_weight(const struct sbitmap *sb)
326{
327 return __sbitmap_weight(sb, true) - sbitmap_cleared(sb);
328}
329EXPORT_SYMBOL_GPL(sbitmap_weight);
330
331void sbitmap_show(struct sbitmap *sb, struct seq_file *m)
332{
333 seq_printf(m, "depth=%u\n", sb->depth);
334 seq_printf(m, "busy=%u\n", sbitmap_weight(sb));
335 seq_printf(m, "cleared=%u\n", sbitmap_cleared(sb));
336 seq_printf(m, "bits_per_word=%u\n", 1U << sb->shift);
337 seq_printf(m, "map_nr=%u\n", sb->map_nr);
338}
339EXPORT_SYMBOL_GPL(sbitmap_show);
340
341static inline void emit_byte(struct seq_file *m, unsigned int offset, u8 byte)
342{
343 if ((offset & 0xf) == 0) {
344 if (offset != 0)
345 seq_putc(m, '\n');
346 seq_printf(m, "%08x:", offset);
347 }
348 if ((offset & 0x1) == 0)
349 seq_putc(m, ' ');
350 seq_printf(m, "%02x", byte);
351}
352
353void sbitmap_bitmap_show(struct sbitmap *sb, struct seq_file *m)
354{
355 u8 byte = 0;
356 unsigned int byte_bits = 0;
357 unsigned int offset = 0;
358 int i;
359
360 for (i = 0; i < sb->map_nr; i++) {
361 unsigned long word = READ_ONCE(sb->map[i].word);
362 unsigned long cleared = READ_ONCE(sb->map[i].cleared);
363 unsigned int word_bits = __map_depth(sb, i);
364
365 word &= ~cleared;
366
367 while (word_bits > 0) {
368 unsigned int bits = min(8 - byte_bits, word_bits);
369
370 byte |= (word & (BIT(bits) - 1)) << byte_bits;
371 byte_bits += bits;
372 if (byte_bits == 8) {
373 emit_byte(m, offset, byte);
374 byte = 0;
375 byte_bits = 0;
376 offset++;
377 }
378 word >>= bits;
379 word_bits -= bits;
380 }
381 }
382 if (byte_bits) {
383 emit_byte(m, offset, byte);
384 offset++;
385 }
386 if (offset)
387 seq_putc(m, '\n');
388}
389EXPORT_SYMBOL_GPL(sbitmap_bitmap_show);
390
391static unsigned int sbq_calc_wake_batch(struct sbitmap_queue *sbq,
392 unsigned int depth)
393{
394 unsigned int wake_batch;
395 unsigned int shallow_depth;
396
397 /*
398 * For each batch, we wake up one queue. We need to make sure that our
399 * batch size is small enough that the full depth of the bitmap,
400 * potentially limited by a shallow depth, is enough to wake up all of
401 * the queues.
402 *
403 * Each full word of the bitmap has bits_per_word bits, and there might
404 * be a partial word. There are depth / bits_per_word full words and
405 * depth % bits_per_word bits left over. In bitwise arithmetic:
406 *
407 * bits_per_word = 1 << shift
408 * depth / bits_per_word = depth >> shift
409 * depth % bits_per_word = depth & ((1 << shift) - 1)
410 *
411 * Each word can be limited to sbq->min_shallow_depth bits.
412 */
413 shallow_depth = min(1U << sbq->sb.shift, sbq->min_shallow_depth);
414 depth = ((depth >> sbq->sb.shift) * shallow_depth +
415 min(depth & ((1U << sbq->sb.shift) - 1), shallow_depth));
416 wake_batch = clamp_t(unsigned int, depth / SBQ_WAIT_QUEUES, 1,
417 SBQ_WAKE_BATCH);
418
419 return wake_batch;
420}
421
422int sbitmap_queue_init_node(struct sbitmap_queue *sbq, unsigned int depth,
423 int shift, bool round_robin, gfp_t flags, int node)
424{
425 int ret;
426 int i;
427
428 ret = sbitmap_init_node(&sbq->sb, depth, shift, flags, node,
429 round_robin, true);
430 if (ret)
431 return ret;
432
433 sbq->min_shallow_depth = UINT_MAX;
434 sbq->wake_batch = sbq_calc_wake_batch(sbq, depth);
435 atomic_set(&sbq->wake_index, 0);
436 atomic_set(&sbq->ws_active, 0);
437
438 sbq->ws = kzalloc_node(SBQ_WAIT_QUEUES * sizeof(*sbq->ws), flags, node);
439 if (!sbq->ws) {
440 sbitmap_free(&sbq->sb);
441 return -ENOMEM;
442 }
443
444 for (i = 0; i < SBQ_WAIT_QUEUES; i++) {
445 init_waitqueue_head(&sbq->ws[i].wait);
446 atomic_set(&sbq->ws[i].wait_cnt, sbq->wake_batch);
447 }
448
449 return 0;
450}
451EXPORT_SYMBOL_GPL(sbitmap_queue_init_node);
452
453static inline void __sbitmap_queue_update_wake_batch(struct sbitmap_queue *sbq,
454 unsigned int wake_batch)
455{
456 int i;
457
458 if (sbq->wake_batch != wake_batch) {
459 WRITE_ONCE(sbq->wake_batch, wake_batch);
460 /*
461 * Pairs with the memory barrier in sbitmap_queue_wake_up()
462 * to ensure that the batch size is updated before the wait
463 * counts.
464 */
465 smp_mb();
466 for (i = 0; i < SBQ_WAIT_QUEUES; i++)
467 atomic_set(&sbq->ws[i].wait_cnt, 1);
468 }
469}
470
471static void sbitmap_queue_update_wake_batch(struct sbitmap_queue *sbq,
472 unsigned int depth)
473{
474 unsigned int wake_batch;
475
476 wake_batch = sbq_calc_wake_batch(sbq, depth);
477 __sbitmap_queue_update_wake_batch(sbq, wake_batch);
478}
479
480void sbitmap_queue_recalculate_wake_batch(struct sbitmap_queue *sbq,
481 unsigned int users)
482{
483 unsigned int wake_batch;
484 unsigned int min_batch;
485 unsigned int depth = (sbq->sb.depth + users - 1) / users;
486
487 min_batch = sbq->sb.depth >= (4 * SBQ_WAIT_QUEUES) ? 4 : 1;
488
489 wake_batch = clamp_val(depth / SBQ_WAIT_QUEUES,
490 min_batch, SBQ_WAKE_BATCH);
491 __sbitmap_queue_update_wake_batch(sbq, wake_batch);
492}
493EXPORT_SYMBOL_GPL(sbitmap_queue_recalculate_wake_batch);
494
495void sbitmap_queue_resize(struct sbitmap_queue *sbq, unsigned int depth)
496{
497 sbitmap_queue_update_wake_batch(sbq, depth);
498 sbitmap_resize(&sbq->sb, depth);
499}
500EXPORT_SYMBOL_GPL(sbitmap_queue_resize);
501
502int __sbitmap_queue_get(struct sbitmap_queue *sbq)
503{
504 return sbitmap_get(&sbq->sb);
505}
506EXPORT_SYMBOL_GPL(__sbitmap_queue_get);
507
508unsigned long __sbitmap_queue_get_batch(struct sbitmap_queue *sbq, int nr_tags,
509 unsigned int *offset)
510{
511 struct sbitmap *sb = &sbq->sb;
512 unsigned int hint, depth;
513 unsigned long index, nr;
514 int i;
515
516 if (unlikely(sb->round_robin))
517 return 0;
518
519 depth = READ_ONCE(sb->depth);
520 hint = update_alloc_hint_before_get(sb, depth);
521
522 index = SB_NR_TO_INDEX(sb, hint);
523
524 for (i = 0; i < sb->map_nr; i++) {
525 struct sbitmap_word *map = &sb->map[index];
526 unsigned long get_mask;
527 unsigned int map_depth = __map_depth(sb, index);
528
529 sbitmap_deferred_clear(map);
530 if (map->word == (1UL << (map_depth - 1)) - 1)
531 goto next;
532
533 nr = find_first_zero_bit(&map->word, map_depth);
534 if (nr + nr_tags <= map_depth) {
535 atomic_long_t *ptr = (atomic_long_t *) &map->word;
536 int map_tags = min_t(int, nr_tags, map_depth);
537 unsigned long val, ret;
538
539 get_mask = ((1UL << map_tags) - 1) << nr;
540 do {
541 val = READ_ONCE(map->word);
542 if ((val & ~get_mask) != val)
543 goto next;
544 ret = atomic_long_cmpxchg(ptr, val, get_mask | val);
545 } while (ret != val);
546 get_mask = (get_mask & ~ret) >> nr;
547 if (get_mask) {
548 *offset = nr + (index << sb->shift);
549 update_alloc_hint_after_get(sb, depth, hint,
550 *offset + map_tags - 1);
551 return get_mask;
552 }
553 }
554next:
555 /* Jump to next index. */
556 if (++index >= sb->map_nr)
557 index = 0;
558 }
559
560 return 0;
561}
562
563int sbitmap_queue_get_shallow(struct sbitmap_queue *sbq,
564 unsigned int shallow_depth)
565{
566 WARN_ON_ONCE(shallow_depth < sbq->min_shallow_depth);
567
568 return sbitmap_get_shallow(&sbq->sb, shallow_depth);
569}
570EXPORT_SYMBOL_GPL(sbitmap_queue_get_shallow);
571
572void sbitmap_queue_min_shallow_depth(struct sbitmap_queue *sbq,
573 unsigned int min_shallow_depth)
574{
575 sbq->min_shallow_depth = min_shallow_depth;
576 sbitmap_queue_update_wake_batch(sbq, sbq->sb.depth);
577}
578EXPORT_SYMBOL_GPL(sbitmap_queue_min_shallow_depth);
579
580static struct sbq_wait_state *sbq_wake_ptr(struct sbitmap_queue *sbq)
581{
582 int i, wake_index;
583
584 if (!atomic_read(&sbq->ws_active))
585 return NULL;
586
587 wake_index = atomic_read(&sbq->wake_index);
588 for (i = 0; i < SBQ_WAIT_QUEUES; i++) {
589 struct sbq_wait_state *ws = &sbq->ws[wake_index];
590
591 if (waitqueue_active(&ws->wait)) {
592 if (wake_index != atomic_read(&sbq->wake_index))
593 atomic_set(&sbq->wake_index, wake_index);
594 return ws;
595 }
596
597 wake_index = sbq_index_inc(wake_index);
598 }
599
600 return NULL;
601}
602
603static bool __sbq_wake_up(struct sbitmap_queue *sbq)
604{
605 struct sbq_wait_state *ws;
606 unsigned int wake_batch;
607 int wait_cnt;
608
609 ws = sbq_wake_ptr(sbq);
610 if (!ws)
611 return false;
612
613 wait_cnt = atomic_dec_return(&ws->wait_cnt);
614 if (wait_cnt <= 0) {
615 int ret;
616
617 wake_batch = READ_ONCE(sbq->wake_batch);
618
619 /*
620 * Pairs with the memory barrier in sbitmap_queue_resize() to
621 * ensure that we see the batch size update before the wait
622 * count is reset.
623 */
624 smp_mb__before_atomic();
625
626 /*
627 * For concurrent callers of this, the one that failed the
628 * atomic_cmpxhcg() race should call this function again
629 * to wakeup a new batch on a different 'ws'.
630 */
631 ret = atomic_cmpxchg(&ws->wait_cnt, wait_cnt, wake_batch);
632 if (ret == wait_cnt) {
633 sbq_index_atomic_inc(&sbq->wake_index);
634 wake_up_nr(&ws->wait, wake_batch);
635 return false;
636 }
637
638 return true;
639 }
640
641 return false;
642}
643
644void sbitmap_queue_wake_up(struct sbitmap_queue *sbq)
645{
646 while (__sbq_wake_up(sbq))
647 ;
648}
649EXPORT_SYMBOL_GPL(sbitmap_queue_wake_up);
650
651static inline void sbitmap_update_cpu_hint(struct sbitmap *sb, int cpu, int tag)
652{
653 if (likely(!sb->round_robin && tag < sb->depth))
654 data_race(*per_cpu_ptr(sb->alloc_hint, cpu) = tag);
655}
656
657void sbitmap_queue_clear_batch(struct sbitmap_queue *sbq, int offset,
658 int *tags, int nr_tags)
659{
660 struct sbitmap *sb = &sbq->sb;
661 unsigned long *addr = NULL;
662 unsigned long mask = 0;
663 int i;
664
665 smp_mb__before_atomic();
666 for (i = 0; i < nr_tags; i++) {
667 const int tag = tags[i] - offset;
668 unsigned long *this_addr;
669
670 /* since we're clearing a batch, skip the deferred map */
671 this_addr = &sb->map[SB_NR_TO_INDEX(sb, tag)].word;
672 if (!addr) {
673 addr = this_addr;
674 } else if (addr != this_addr) {
675 atomic_long_andnot(mask, (atomic_long_t *) addr);
676 mask = 0;
677 addr = this_addr;
678 }
679 mask |= (1UL << SB_NR_TO_BIT(sb, tag));
680 }
681
682 if (mask)
683 atomic_long_andnot(mask, (atomic_long_t *) addr);
684
685 smp_mb__after_atomic();
686 sbitmap_queue_wake_up(sbq);
687 sbitmap_update_cpu_hint(&sbq->sb, raw_smp_processor_id(),
688 tags[nr_tags - 1] - offset);
689}
690
691void sbitmap_queue_clear(struct sbitmap_queue *sbq, unsigned int nr,
692 unsigned int cpu)
693{
694 /*
695 * Once the clear bit is set, the bit may be allocated out.
696 *
697 * Orders READ/WRITE on the associated instance(such as request
698 * of blk_mq) by this bit for avoiding race with re-allocation,
699 * and its pair is the memory barrier implied in __sbitmap_get_word.
700 *
701 * One invariant is that the clear bit has to be zero when the bit
702 * is in use.
703 */
704 smp_mb__before_atomic();
705 sbitmap_deferred_clear_bit(&sbq->sb, nr);
706
707 /*
708 * Pairs with the memory barrier in set_current_state() to ensure the
709 * proper ordering of clear_bit_unlock()/waitqueue_active() in the waker
710 * and test_and_set_bit_lock()/prepare_to_wait()/finish_wait() in the
711 * waiter. See the comment on waitqueue_active().
712 */
713 smp_mb__after_atomic();
714 sbitmap_queue_wake_up(sbq);
715 sbitmap_update_cpu_hint(&sbq->sb, cpu, nr);
716}
717EXPORT_SYMBOL_GPL(sbitmap_queue_clear);
718
719void sbitmap_queue_wake_all(struct sbitmap_queue *sbq)
720{
721 int i, wake_index;
722
723 /*
724 * Pairs with the memory barrier in set_current_state() like in
725 * sbitmap_queue_wake_up().
726 */
727 smp_mb();
728 wake_index = atomic_read(&sbq->wake_index);
729 for (i = 0; i < SBQ_WAIT_QUEUES; i++) {
730 struct sbq_wait_state *ws = &sbq->ws[wake_index];
731
732 if (waitqueue_active(&ws->wait))
733 wake_up(&ws->wait);
734
735 wake_index = sbq_index_inc(wake_index);
736 }
737}
738EXPORT_SYMBOL_GPL(sbitmap_queue_wake_all);
739
740void sbitmap_queue_show(struct sbitmap_queue *sbq, struct seq_file *m)
741{
742 bool first;
743 int i;
744
745 sbitmap_show(&sbq->sb, m);
746
747 seq_puts(m, "alloc_hint={");
748 first = true;
749 for_each_possible_cpu(i) {
750 if (!first)
751 seq_puts(m, ", ");
752 first = false;
753 seq_printf(m, "%u", *per_cpu_ptr(sbq->sb.alloc_hint, i));
754 }
755 seq_puts(m, "}\n");
756
757 seq_printf(m, "wake_batch=%u\n", sbq->wake_batch);
758 seq_printf(m, "wake_index=%d\n", atomic_read(&sbq->wake_index));
759 seq_printf(m, "ws_active=%d\n", atomic_read(&sbq->ws_active));
760
761 seq_puts(m, "ws={\n");
762 for (i = 0; i < SBQ_WAIT_QUEUES; i++) {
763 struct sbq_wait_state *ws = &sbq->ws[i];
764
765 seq_printf(m, "\t{.wait_cnt=%d, .wait=%s},\n",
766 atomic_read(&ws->wait_cnt),
767 waitqueue_active(&ws->wait) ? "active" : "inactive");
768 }
769 seq_puts(m, "}\n");
770
771 seq_printf(m, "round_robin=%d\n", sbq->sb.round_robin);
772 seq_printf(m, "min_shallow_depth=%u\n", sbq->min_shallow_depth);
773}
774EXPORT_SYMBOL_GPL(sbitmap_queue_show);
775
776void sbitmap_add_wait_queue(struct sbitmap_queue *sbq,
777 struct sbq_wait_state *ws,
778 struct sbq_wait *sbq_wait)
779{
780 if (!sbq_wait->sbq) {
781 sbq_wait->sbq = sbq;
782 atomic_inc(&sbq->ws_active);
783 add_wait_queue(&ws->wait, &sbq_wait->wait);
784 }
785}
786EXPORT_SYMBOL_GPL(sbitmap_add_wait_queue);
787
788void sbitmap_del_wait_queue(struct sbq_wait *sbq_wait)
789{
790 list_del_init(&sbq_wait->wait.entry);
791 if (sbq_wait->sbq) {
792 atomic_dec(&sbq_wait->sbq->ws_active);
793 sbq_wait->sbq = NULL;
794 }
795}
796EXPORT_SYMBOL_GPL(sbitmap_del_wait_queue);
797
798void sbitmap_prepare_to_wait(struct sbitmap_queue *sbq,
799 struct sbq_wait_state *ws,
800 struct sbq_wait *sbq_wait, int state)
801{
802 if (!sbq_wait->sbq) {
803 atomic_inc(&sbq->ws_active);
804 sbq_wait->sbq = sbq;
805 }
806 prepare_to_wait_exclusive(&ws->wait, &sbq_wait->wait, state);
807}
808EXPORT_SYMBOL_GPL(sbitmap_prepare_to_wait);
809
810void sbitmap_finish_wait(struct sbitmap_queue *sbq, struct sbq_wait_state *ws,
811 struct sbq_wait *sbq_wait)
812{
813 finish_wait(&ws->wait, &sbq_wait->wait);
814 if (sbq_wait->sbq) {
815 atomic_dec(&sbq->ws_active);
816 sbq_wait->sbq = NULL;
817 }
818}
819EXPORT_SYMBOL_GPL(sbitmap_finish_wait);