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- // SPDX-License-Identifier: GPL-2.0-only
- /*
- * Copyright (C) 2016 Facebook
- * Copyright (C) 2013-2014 Jens Axboe
- */
- #include <linux/sched.h>
- #include <linux/random.h>
- #include <linux/sbitmap.h>
- #include <linux/seq_file.h>
- static int init_alloc_hint(struct sbitmap *sb, gfp_t flags)
- {
- unsigned depth = sb->depth;
- sb->alloc_hint = alloc_percpu_gfp(unsigned int, flags);
- if (!sb->alloc_hint)
- return -ENOMEM;
- if (depth && !sb->round_robin) {
- int i;
- for_each_possible_cpu(i)
- *per_cpu_ptr(sb->alloc_hint, i) = prandom_u32_max(depth);
- }
- return 0;
- }
- static inline unsigned update_alloc_hint_before_get(struct sbitmap *sb,
- unsigned int depth)
- {
- unsigned hint;
- hint = this_cpu_read(*sb->alloc_hint);
- if (unlikely(hint >= depth)) {
- hint = depth ? prandom_u32_max(depth) : 0;
- this_cpu_write(*sb->alloc_hint, hint);
- }
- return hint;
- }
- static inline void update_alloc_hint_after_get(struct sbitmap *sb,
- unsigned int depth,
- unsigned int hint,
- unsigned int nr)
- {
- if (nr == -1) {
- /* If the map is full, a hint won't do us much good. */
- this_cpu_write(*sb->alloc_hint, 0);
- } else if (nr == hint || unlikely(sb->round_robin)) {
- /* Only update the hint if we used it. */
- hint = nr + 1;
- if (hint >= depth - 1)
- hint = 0;
- this_cpu_write(*sb->alloc_hint, hint);
- }
- }
- /*
- * See if we have deferred clears that we can batch move
- */
- static inline bool sbitmap_deferred_clear(struct sbitmap_word *map)
- {
- unsigned long mask;
- if (!READ_ONCE(map->cleared))
- return false;
- /*
- * First get a stable cleared mask, setting the old mask to 0.
- */
- mask = xchg(&map->cleared, 0);
- /*
- * Now clear the masked bits in our free word
- */
- atomic_long_andnot(mask, (atomic_long_t *)&map->word);
- BUILD_BUG_ON(sizeof(atomic_long_t) != sizeof(map->word));
- return true;
- }
- int sbitmap_init_node(struct sbitmap *sb, unsigned int depth, int shift,
- gfp_t flags, int node, bool round_robin,
- bool alloc_hint)
- {
- unsigned int bits_per_word;
- if (shift < 0)
- shift = sbitmap_calculate_shift(depth);
- bits_per_word = 1U << shift;
- if (bits_per_word > BITS_PER_LONG)
- return -EINVAL;
- sb->shift = shift;
- sb->depth = depth;
- sb->map_nr = DIV_ROUND_UP(sb->depth, bits_per_word);
- sb->round_robin = round_robin;
- if (depth == 0) {
- sb->map = NULL;
- return 0;
- }
- if (alloc_hint) {
- if (init_alloc_hint(sb, flags))
- return -ENOMEM;
- } else {
- sb->alloc_hint = NULL;
- }
- sb->map = kvzalloc_node(sb->map_nr * sizeof(*sb->map), flags, node);
- if (!sb->map) {
- free_percpu(sb->alloc_hint);
- return -ENOMEM;
- }
- return 0;
- }
- EXPORT_SYMBOL_GPL(sbitmap_init_node);
- void sbitmap_resize(struct sbitmap *sb, unsigned int depth)
- {
- unsigned int bits_per_word = 1U << sb->shift;
- unsigned int i;
- for (i = 0; i < sb->map_nr; i++)
- sbitmap_deferred_clear(&sb->map[i]);
- sb->depth = depth;
- sb->map_nr = DIV_ROUND_UP(sb->depth, bits_per_word);
- }
- EXPORT_SYMBOL_GPL(sbitmap_resize);
- static int __sbitmap_get_word(unsigned long *word, unsigned long depth,
- unsigned int hint, bool wrap)
- {
- int nr;
- /* don't wrap if starting from 0 */
- wrap = wrap && hint;
- while (1) {
- nr = find_next_zero_bit(word, depth, hint);
- if (unlikely(nr >= depth)) {
- /*
- * We started with an offset, and we didn't reset the
- * offset to 0 in a failure case, so start from 0 to
- * exhaust the map.
- */
- if (hint && wrap) {
- hint = 0;
- continue;
- }
- return -1;
- }
- if (!test_and_set_bit_lock(nr, word))
- break;
- hint = nr + 1;
- if (hint >= depth - 1)
- hint = 0;
- }
- return nr;
- }
- static int sbitmap_find_bit_in_index(struct sbitmap *sb, int index,
- unsigned int alloc_hint)
- {
- struct sbitmap_word *map = &sb->map[index];
- int nr;
- do {
- nr = __sbitmap_get_word(&map->word, __map_depth(sb, index),
- alloc_hint, !sb->round_robin);
- if (nr != -1)
- break;
- if (!sbitmap_deferred_clear(map))
- break;
- } while (1);
- return nr;
- }
- static int __sbitmap_get(struct sbitmap *sb, unsigned int alloc_hint)
- {
- unsigned int i, index;
- int nr = -1;
- index = SB_NR_TO_INDEX(sb, alloc_hint);
- /*
- * Unless we're doing round robin tag allocation, just use the
- * alloc_hint to find the right word index. No point in looping
- * twice in find_next_zero_bit() for that case.
- */
- if (sb->round_robin)
- alloc_hint = SB_NR_TO_BIT(sb, alloc_hint);
- else
- alloc_hint = 0;
- for (i = 0; i < sb->map_nr; i++) {
- nr = sbitmap_find_bit_in_index(sb, index, alloc_hint);
- if (nr != -1) {
- nr += index << sb->shift;
- break;
- }
- /* Jump to next index. */
- alloc_hint = 0;
- if (++index >= sb->map_nr)
- index = 0;
- }
- return nr;
- }
- int sbitmap_get(struct sbitmap *sb)
- {
- int nr;
- unsigned int hint, depth;
- if (WARN_ON_ONCE(unlikely(!sb->alloc_hint)))
- return -1;
- depth = READ_ONCE(sb->depth);
- hint = update_alloc_hint_before_get(sb, depth);
- nr = __sbitmap_get(sb, hint);
- update_alloc_hint_after_get(sb, depth, hint, nr);
- return nr;
- }
- EXPORT_SYMBOL_GPL(sbitmap_get);
- static int __sbitmap_get_shallow(struct sbitmap *sb,
- unsigned int alloc_hint,
- unsigned long shallow_depth)
- {
- unsigned int i, index;
- int nr = -1;
- index = SB_NR_TO_INDEX(sb, alloc_hint);
- for (i = 0; i < sb->map_nr; i++) {
- again:
- nr = __sbitmap_get_word(&sb->map[index].word,
- min_t(unsigned int,
- __map_depth(sb, index),
- shallow_depth),
- SB_NR_TO_BIT(sb, alloc_hint), true);
- if (nr != -1) {
- nr += index << sb->shift;
- break;
- }
- if (sbitmap_deferred_clear(&sb->map[index]))
- goto again;
- /* Jump to next index. */
- index++;
- alloc_hint = index << sb->shift;
- if (index >= sb->map_nr) {
- index = 0;
- alloc_hint = 0;
- }
- }
- return nr;
- }
- int sbitmap_get_shallow(struct sbitmap *sb, unsigned long shallow_depth)
- {
- int nr;
- unsigned int hint, depth;
- if (WARN_ON_ONCE(unlikely(!sb->alloc_hint)))
- return -1;
- depth = READ_ONCE(sb->depth);
- hint = update_alloc_hint_before_get(sb, depth);
- nr = __sbitmap_get_shallow(sb, hint, shallow_depth);
- update_alloc_hint_after_get(sb, depth, hint, nr);
- return nr;
- }
- EXPORT_SYMBOL_GPL(sbitmap_get_shallow);
- bool sbitmap_any_bit_set(const struct sbitmap *sb)
- {
- unsigned int i;
- for (i = 0; i < sb->map_nr; i++) {
- if (sb->map[i].word & ~sb->map[i].cleared)
- return true;
- }
- return false;
- }
- EXPORT_SYMBOL_GPL(sbitmap_any_bit_set);
- static unsigned int __sbitmap_weight(const struct sbitmap *sb, bool set)
- {
- unsigned int i, weight = 0;
- for (i = 0; i < sb->map_nr; i++) {
- const struct sbitmap_word *word = &sb->map[i];
- unsigned int word_depth = __map_depth(sb, i);
- if (set)
- weight += bitmap_weight(&word->word, word_depth);
- else
- weight += bitmap_weight(&word->cleared, word_depth);
- }
- return weight;
- }
- static unsigned int sbitmap_cleared(const struct sbitmap *sb)
- {
- return __sbitmap_weight(sb, false);
- }
- unsigned int sbitmap_weight(const struct sbitmap *sb)
- {
- return __sbitmap_weight(sb, true) - sbitmap_cleared(sb);
- }
- EXPORT_SYMBOL_GPL(sbitmap_weight);
- void sbitmap_show(struct sbitmap *sb, struct seq_file *m)
- {
- seq_printf(m, "depth=%u\n", sb->depth);
- seq_printf(m, "busy=%u\n", sbitmap_weight(sb));
- seq_printf(m, "cleared=%u\n", sbitmap_cleared(sb));
- seq_printf(m, "bits_per_word=%u\n", 1U << sb->shift);
- seq_printf(m, "map_nr=%u\n", sb->map_nr);
- }
- EXPORT_SYMBOL_GPL(sbitmap_show);
- static inline void emit_byte(struct seq_file *m, unsigned int offset, u8 byte)
- {
- if ((offset & 0xf) == 0) {
- if (offset != 0)
- seq_putc(m, '\n');
- seq_printf(m, "%08x:", offset);
- }
- if ((offset & 0x1) == 0)
- seq_putc(m, ' ');
- seq_printf(m, "%02x", byte);
- }
- void sbitmap_bitmap_show(struct sbitmap *sb, struct seq_file *m)
- {
- u8 byte = 0;
- unsigned int byte_bits = 0;
- unsigned int offset = 0;
- int i;
- for (i = 0; i < sb->map_nr; i++) {
- unsigned long word = READ_ONCE(sb->map[i].word);
- unsigned long cleared = READ_ONCE(sb->map[i].cleared);
- unsigned int word_bits = __map_depth(sb, i);
- word &= ~cleared;
- while (word_bits > 0) {
- unsigned int bits = min(8 - byte_bits, word_bits);
- byte |= (word & (BIT(bits) - 1)) << byte_bits;
- byte_bits += bits;
- if (byte_bits == 8) {
- emit_byte(m, offset, byte);
- byte = 0;
- byte_bits = 0;
- offset++;
- }
- word >>= bits;
- word_bits -= bits;
- }
- }
- if (byte_bits) {
- emit_byte(m, offset, byte);
- offset++;
- }
- if (offset)
- seq_putc(m, '\n');
- }
- EXPORT_SYMBOL_GPL(sbitmap_bitmap_show);
- static unsigned int sbq_calc_wake_batch(struct sbitmap_queue *sbq,
- unsigned int depth)
- {
- unsigned int wake_batch;
- unsigned int shallow_depth;
- /*
- * For each batch, we wake up one queue. We need to make sure that our
- * batch size is small enough that the full depth of the bitmap,
- * potentially limited by a shallow depth, is enough to wake up all of
- * the queues.
- *
- * Each full word of the bitmap has bits_per_word bits, and there might
- * be a partial word. There are depth / bits_per_word full words and
- * depth % bits_per_word bits left over. In bitwise arithmetic:
- *
- * bits_per_word = 1 << shift
- * depth / bits_per_word = depth >> shift
- * depth % bits_per_word = depth & ((1 << shift) - 1)
- *
- * Each word can be limited to sbq->min_shallow_depth bits.
- */
- shallow_depth = min(1U << sbq->sb.shift, sbq->min_shallow_depth);
- depth = ((depth >> sbq->sb.shift) * shallow_depth +
- min(depth & ((1U << sbq->sb.shift) - 1), shallow_depth));
- wake_batch = clamp_t(unsigned int, depth / SBQ_WAIT_QUEUES, 1,
- SBQ_WAKE_BATCH);
- return wake_batch;
- }
- int sbitmap_queue_init_node(struct sbitmap_queue *sbq, unsigned int depth,
- int shift, bool round_robin, gfp_t flags, int node)
- {
- int ret;
- int i;
- ret = sbitmap_init_node(&sbq->sb, depth, shift, flags, node,
- round_robin, true);
- if (ret)
- return ret;
- sbq->min_shallow_depth = UINT_MAX;
- sbq->wake_batch = sbq_calc_wake_batch(sbq, depth);
- atomic_set(&sbq->wake_index, 0);
- atomic_set(&sbq->ws_active, 0);
- atomic_set(&sbq->completion_cnt, 0);
- atomic_set(&sbq->wakeup_cnt, 0);
- sbq->ws = kzalloc_node(SBQ_WAIT_QUEUES * sizeof(*sbq->ws), flags, node);
- if (!sbq->ws) {
- sbitmap_free(&sbq->sb);
- return -ENOMEM;
- }
- for (i = 0; i < SBQ_WAIT_QUEUES; i++)
- init_waitqueue_head(&sbq->ws[i].wait);
- return 0;
- }
- EXPORT_SYMBOL_GPL(sbitmap_queue_init_node);
- static void sbitmap_queue_update_wake_batch(struct sbitmap_queue *sbq,
- unsigned int depth)
- {
- unsigned int wake_batch;
- wake_batch = sbq_calc_wake_batch(sbq, depth);
- if (sbq->wake_batch != wake_batch)
- WRITE_ONCE(sbq->wake_batch, wake_batch);
- }
- void sbitmap_queue_recalculate_wake_batch(struct sbitmap_queue *sbq,
- unsigned int users)
- {
- unsigned int wake_batch;
- unsigned int depth = (sbq->sb.depth + users - 1) / users;
- wake_batch = clamp_val(depth / SBQ_WAIT_QUEUES,
- 1, SBQ_WAKE_BATCH);
- WRITE_ONCE(sbq->wake_batch, wake_batch);
- }
- EXPORT_SYMBOL_GPL(sbitmap_queue_recalculate_wake_batch);
- void sbitmap_queue_resize(struct sbitmap_queue *sbq, unsigned int depth)
- {
- sbitmap_queue_update_wake_batch(sbq, depth);
- sbitmap_resize(&sbq->sb, depth);
- }
- EXPORT_SYMBOL_GPL(sbitmap_queue_resize);
- int __sbitmap_queue_get(struct sbitmap_queue *sbq)
- {
- return sbitmap_get(&sbq->sb);
- }
- EXPORT_SYMBOL_GPL(__sbitmap_queue_get);
- unsigned long __sbitmap_queue_get_batch(struct sbitmap_queue *sbq, int nr_tags,
- unsigned int *offset)
- {
- struct sbitmap *sb = &sbq->sb;
- unsigned int hint, depth;
- unsigned long index, nr;
- int i;
- if (unlikely(sb->round_robin))
- return 0;
- depth = READ_ONCE(sb->depth);
- hint = update_alloc_hint_before_get(sb, depth);
- index = SB_NR_TO_INDEX(sb, hint);
- for (i = 0; i < sb->map_nr; i++) {
- struct sbitmap_word *map = &sb->map[index];
- unsigned long get_mask;
- unsigned int map_depth = __map_depth(sb, index);
- sbitmap_deferred_clear(map);
- if (map->word == (1UL << (map_depth - 1)) - 1)
- goto next;
- nr = find_first_zero_bit(&map->word, map_depth);
- if (nr + nr_tags <= map_depth) {
- atomic_long_t *ptr = (atomic_long_t *) &map->word;
- unsigned long val;
- get_mask = ((1UL << nr_tags) - 1) << nr;
- val = READ_ONCE(map->word);
- while (!atomic_long_try_cmpxchg(ptr, &val,
- get_mask | val))
- ;
- get_mask = (get_mask & ~val) >> nr;
- if (get_mask) {
- *offset = nr + (index << sb->shift);
- update_alloc_hint_after_get(sb, depth, hint,
- *offset + nr_tags - 1);
- return get_mask;
- }
- }
- next:
- /* Jump to next index. */
- if (++index >= sb->map_nr)
- index = 0;
- }
- return 0;
- }
- int sbitmap_queue_get_shallow(struct sbitmap_queue *sbq,
- unsigned int shallow_depth)
- {
- WARN_ON_ONCE(shallow_depth < sbq->min_shallow_depth);
- return sbitmap_get_shallow(&sbq->sb, shallow_depth);
- }
- EXPORT_SYMBOL_GPL(sbitmap_queue_get_shallow);
- void sbitmap_queue_min_shallow_depth(struct sbitmap_queue *sbq,
- unsigned int min_shallow_depth)
- {
- sbq->min_shallow_depth = min_shallow_depth;
- sbitmap_queue_update_wake_batch(sbq, sbq->sb.depth);
- }
- EXPORT_SYMBOL_GPL(sbitmap_queue_min_shallow_depth);
- static void __sbitmap_queue_wake_up(struct sbitmap_queue *sbq, int nr)
- {
- int i, wake_index;
- if (!atomic_read(&sbq->ws_active))
- return;
- wake_index = atomic_read(&sbq->wake_index);
- for (i = 0; i < SBQ_WAIT_QUEUES; i++) {
- struct sbq_wait_state *ws = &sbq->ws[wake_index];
- /*
- * Advance the index before checking the current queue.
- * It improves fairness, by ensuring the queue doesn't
- * need to be fully emptied before trying to wake up
- * from the next one.
- */
- wake_index = sbq_index_inc(wake_index);
- /*
- * It is sufficient to wake up at least one waiter to
- * guarantee forward progress.
- */
- if (waitqueue_active(&ws->wait) &&
- wake_up_nr(&ws->wait, nr))
- break;
- }
- if (wake_index != atomic_read(&sbq->wake_index))
- atomic_set(&sbq->wake_index, wake_index);
- }
- void sbitmap_queue_wake_up(struct sbitmap_queue *sbq, int nr)
- {
- unsigned int wake_batch = READ_ONCE(sbq->wake_batch);
- unsigned int wakeups;
- if (!atomic_read(&sbq->ws_active))
- return;
- atomic_add(nr, &sbq->completion_cnt);
- wakeups = atomic_read(&sbq->wakeup_cnt);
- do {
- if (atomic_read(&sbq->completion_cnt) - wakeups < wake_batch)
- return;
- } while (!atomic_try_cmpxchg(&sbq->wakeup_cnt,
- &wakeups, wakeups + wake_batch));
- __sbitmap_queue_wake_up(sbq, wake_batch);
- }
- EXPORT_SYMBOL_GPL(sbitmap_queue_wake_up);
- static inline void sbitmap_update_cpu_hint(struct sbitmap *sb, int cpu, int tag)
- {
- if (likely(!sb->round_robin && tag < sb->depth))
- data_race(*per_cpu_ptr(sb->alloc_hint, cpu) = tag);
- }
- void sbitmap_queue_clear_batch(struct sbitmap_queue *sbq, int offset,
- int *tags, int nr_tags)
- {
- struct sbitmap *sb = &sbq->sb;
- unsigned long *addr = NULL;
- unsigned long mask = 0;
- int i;
- smp_mb__before_atomic();
- for (i = 0; i < nr_tags; i++) {
- const int tag = tags[i] - offset;
- unsigned long *this_addr;
- /* since we're clearing a batch, skip the deferred map */
- this_addr = &sb->map[SB_NR_TO_INDEX(sb, tag)].word;
- if (!addr) {
- addr = this_addr;
- } else if (addr != this_addr) {
- atomic_long_andnot(mask, (atomic_long_t *) addr);
- mask = 0;
- addr = this_addr;
- }
- mask |= (1UL << SB_NR_TO_BIT(sb, tag));
- }
- if (mask)
- atomic_long_andnot(mask, (atomic_long_t *) addr);
- smp_mb__after_atomic();
- sbitmap_queue_wake_up(sbq, nr_tags);
- sbitmap_update_cpu_hint(&sbq->sb, raw_smp_processor_id(),
- tags[nr_tags - 1] - offset);
- }
- void sbitmap_queue_clear(struct sbitmap_queue *sbq, unsigned int nr,
- unsigned int cpu)
- {
- /*
- * Once the clear bit is set, the bit may be allocated out.
- *
- * Orders READ/WRITE on the associated instance(such as request
- * of blk_mq) by this bit for avoiding race with re-allocation,
- * and its pair is the memory barrier implied in __sbitmap_get_word.
- *
- * One invariant is that the clear bit has to be zero when the bit
- * is in use.
- */
- smp_mb__before_atomic();
- sbitmap_deferred_clear_bit(&sbq->sb, nr);
- /*
- * Pairs with the memory barrier in set_current_state() to ensure the
- * proper ordering of clear_bit_unlock()/waitqueue_active() in the waker
- * and test_and_set_bit_lock()/prepare_to_wait()/finish_wait() in the
- * waiter. See the comment on waitqueue_active().
- */
- smp_mb__after_atomic();
- sbitmap_queue_wake_up(sbq, 1);
- sbitmap_update_cpu_hint(&sbq->sb, cpu, nr);
- }
- EXPORT_SYMBOL_GPL(sbitmap_queue_clear);
- void sbitmap_queue_wake_all(struct sbitmap_queue *sbq)
- {
- int i, wake_index;
- /*
- * Pairs with the memory barrier in set_current_state() like in
- * sbitmap_queue_wake_up().
- */
- smp_mb();
- wake_index = atomic_read(&sbq->wake_index);
- for (i = 0; i < SBQ_WAIT_QUEUES; i++) {
- struct sbq_wait_state *ws = &sbq->ws[wake_index];
- if (waitqueue_active(&ws->wait))
- wake_up(&ws->wait);
- wake_index = sbq_index_inc(wake_index);
- }
- }
- EXPORT_SYMBOL_GPL(sbitmap_queue_wake_all);
- void sbitmap_queue_show(struct sbitmap_queue *sbq, struct seq_file *m)
- {
- bool first;
- int i;
- sbitmap_show(&sbq->sb, m);
- seq_puts(m, "alloc_hint={");
- first = true;
- for_each_possible_cpu(i) {
- if (!first)
- seq_puts(m, ", ");
- first = false;
- seq_printf(m, "%u", *per_cpu_ptr(sbq->sb.alloc_hint, i));
- }
- seq_puts(m, "}\n");
- seq_printf(m, "wake_batch=%u\n", sbq->wake_batch);
- seq_printf(m, "wake_index=%d\n", atomic_read(&sbq->wake_index));
- seq_printf(m, "ws_active=%d\n", atomic_read(&sbq->ws_active));
- seq_puts(m, "ws={\n");
- for (i = 0; i < SBQ_WAIT_QUEUES; i++) {
- struct sbq_wait_state *ws = &sbq->ws[i];
- seq_printf(m, "\t{.wait=%s},\n",
- waitqueue_active(&ws->wait) ? "active" : "inactive");
- }
- seq_puts(m, "}\n");
- seq_printf(m, "round_robin=%d\n", sbq->sb.round_robin);
- seq_printf(m, "min_shallow_depth=%u\n", sbq->min_shallow_depth);
- }
- EXPORT_SYMBOL_GPL(sbitmap_queue_show);
- void sbitmap_add_wait_queue(struct sbitmap_queue *sbq,
- struct sbq_wait_state *ws,
- struct sbq_wait *sbq_wait)
- {
- if (!sbq_wait->sbq) {
- sbq_wait->sbq = sbq;
- atomic_inc(&sbq->ws_active);
- add_wait_queue(&ws->wait, &sbq_wait->wait);
- }
- }
- EXPORT_SYMBOL_GPL(sbitmap_add_wait_queue);
- void sbitmap_del_wait_queue(struct sbq_wait *sbq_wait)
- {
- list_del_init(&sbq_wait->wait.entry);
- if (sbq_wait->sbq) {
- atomic_dec(&sbq_wait->sbq->ws_active);
- sbq_wait->sbq = NULL;
- }
- }
- EXPORT_SYMBOL_GPL(sbitmap_del_wait_queue);
- void sbitmap_prepare_to_wait(struct sbitmap_queue *sbq,
- struct sbq_wait_state *ws,
- struct sbq_wait *sbq_wait, int state)
- {
- if (!sbq_wait->sbq) {
- atomic_inc(&sbq->ws_active);
- sbq_wait->sbq = sbq;
- }
- prepare_to_wait_exclusive(&ws->wait, &sbq_wait->wait, state);
- }
- EXPORT_SYMBOL_GPL(sbitmap_prepare_to_wait);
- void sbitmap_finish_wait(struct sbitmap_queue *sbq, struct sbq_wait_state *ws,
- struct sbq_wait *sbq_wait)
- {
- finish_wait(&ws->wait, &sbq_wait->wait);
- if (sbq_wait->sbq) {
- atomic_dec(&sbq->ws_active);
- sbq_wait->sbq = NULL;
- }
- }
- EXPORT_SYMBOL_GPL(sbitmap_finish_wait);
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