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816 lines
19 KiB
816 lines
19 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* Copyright (C) 2016 Facebook |
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* Copyright (C) 2013-2014 Jens Axboe |
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*/ |
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|
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#include <linux/sched.h> |
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#include <linux/random.h> |
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#include <linux/sbitmap.h> |
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#include <linux/seq_file.h> |
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static int init_alloc_hint(struct sbitmap *sb, gfp_t flags) |
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{ |
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unsigned depth = sb->depth; |
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sb->alloc_hint = alloc_percpu_gfp(unsigned int, flags); |
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if (!sb->alloc_hint) |
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return -ENOMEM; |
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if (depth && !sb->round_robin) { |
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int i; |
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for_each_possible_cpu(i) |
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*per_cpu_ptr(sb->alloc_hint, i) = prandom_u32() % depth; |
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} |
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return 0; |
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} |
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static inline unsigned update_alloc_hint_before_get(struct sbitmap *sb, |
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unsigned int depth) |
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{ |
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unsigned hint; |
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hint = this_cpu_read(*sb->alloc_hint); |
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if (unlikely(hint >= depth)) { |
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hint = depth ? prandom_u32() % depth : 0; |
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this_cpu_write(*sb->alloc_hint, hint); |
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} |
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return hint; |
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} |
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static inline void update_alloc_hint_after_get(struct sbitmap *sb, |
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unsigned int depth, |
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unsigned int hint, |
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unsigned int nr) |
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{ |
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if (nr == -1) { |
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/* If the map is full, a hint won't do us much good. */ |
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this_cpu_write(*sb->alloc_hint, 0); |
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} else if (nr == hint || unlikely(sb->round_robin)) { |
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/* Only update the hint if we used it. */ |
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hint = nr + 1; |
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if (hint >= depth - 1) |
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hint = 0; |
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this_cpu_write(*sb->alloc_hint, hint); |
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} |
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} |
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/* |
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* See if we have deferred clears that we can batch move |
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*/ |
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static inline bool sbitmap_deferred_clear(struct sbitmap_word *map) |
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{ |
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unsigned long mask; |
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if (!READ_ONCE(map->cleared)) |
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return false; |
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/* |
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* First get a stable cleared mask, setting the old mask to 0. |
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*/ |
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mask = xchg(&map->cleared, 0); |
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/* |
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* Now clear the masked bits in our free word |
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*/ |
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atomic_long_andnot(mask, (atomic_long_t *)&map->word); |
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BUILD_BUG_ON(sizeof(atomic_long_t) != sizeof(map->word)); |
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return true; |
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} |
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int sbitmap_init_node(struct sbitmap *sb, unsigned int depth, int shift, |
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gfp_t flags, int node, bool round_robin, |
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bool alloc_hint) |
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{ |
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unsigned int bits_per_word; |
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if (shift < 0) |
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shift = sbitmap_calculate_shift(depth); |
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bits_per_word = 1U << shift; |
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if (bits_per_word > BITS_PER_LONG) |
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return -EINVAL; |
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sb->shift = shift; |
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sb->depth = depth; |
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sb->map_nr = DIV_ROUND_UP(sb->depth, bits_per_word); |
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sb->round_robin = round_robin; |
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if (depth == 0) { |
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sb->map = NULL; |
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return 0; |
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} |
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if (alloc_hint) { |
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if (init_alloc_hint(sb, flags)) |
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return -ENOMEM; |
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} else { |
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sb->alloc_hint = NULL; |
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} |
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sb->map = kvzalloc_node(sb->map_nr * sizeof(*sb->map), flags, node); |
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if (!sb->map) { |
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free_percpu(sb->alloc_hint); |
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return -ENOMEM; |
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} |
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return 0; |
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} |
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EXPORT_SYMBOL_GPL(sbitmap_init_node); |
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void sbitmap_resize(struct sbitmap *sb, unsigned int depth) |
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{ |
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unsigned int bits_per_word = 1U << sb->shift; |
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unsigned int i; |
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for (i = 0; i < sb->map_nr; i++) |
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sbitmap_deferred_clear(&sb->map[i]); |
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sb->depth = depth; |
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sb->map_nr = DIV_ROUND_UP(sb->depth, bits_per_word); |
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} |
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EXPORT_SYMBOL_GPL(sbitmap_resize); |
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static int __sbitmap_get_word(unsigned long *word, unsigned long depth, |
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unsigned int hint, bool wrap) |
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{ |
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int nr; |
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/* don't wrap if starting from 0 */ |
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wrap = wrap && hint; |
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while (1) { |
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nr = find_next_zero_bit(word, depth, hint); |
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if (unlikely(nr >= depth)) { |
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/* |
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* We started with an offset, and we didn't reset the |
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* offset to 0 in a failure case, so start from 0 to |
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* exhaust the map. |
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*/ |
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if (hint && wrap) { |
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hint = 0; |
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continue; |
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} |
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return -1; |
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} |
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if (!test_and_set_bit_lock(nr, word)) |
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break; |
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hint = nr + 1; |
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if (hint >= depth - 1) |
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hint = 0; |
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} |
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return nr; |
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} |
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static int sbitmap_find_bit_in_index(struct sbitmap *sb, int index, |
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unsigned int alloc_hint) |
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{ |
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struct sbitmap_word *map = &sb->map[index]; |
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int nr; |
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do { |
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nr = __sbitmap_get_word(&map->word, __map_depth(sb, index), |
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alloc_hint, !sb->round_robin); |
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if (nr != -1) |
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break; |
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if (!sbitmap_deferred_clear(map)) |
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break; |
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} while (1); |
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return nr; |
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} |
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static int __sbitmap_get(struct sbitmap *sb, unsigned int alloc_hint) |
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{ |
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unsigned int i, index; |
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int nr = -1; |
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index = SB_NR_TO_INDEX(sb, alloc_hint); |
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/* |
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* Unless we're doing round robin tag allocation, just use the |
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* alloc_hint to find the right word index. No point in looping |
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* twice in find_next_zero_bit() for that case. |
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*/ |
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if (sb->round_robin) |
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alloc_hint = SB_NR_TO_BIT(sb, alloc_hint); |
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else |
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alloc_hint = 0; |
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for (i = 0; i < sb->map_nr; i++) { |
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nr = sbitmap_find_bit_in_index(sb, index, alloc_hint); |
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if (nr != -1) { |
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nr += index << sb->shift; |
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break; |
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} |
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/* Jump to next index. */ |
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alloc_hint = 0; |
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if (++index >= sb->map_nr) |
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index = 0; |
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} |
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return nr; |
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} |
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int sbitmap_get(struct sbitmap *sb) |
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{ |
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int nr; |
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unsigned int hint, depth; |
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if (WARN_ON_ONCE(unlikely(!sb->alloc_hint))) |
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return -1; |
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depth = READ_ONCE(sb->depth); |
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hint = update_alloc_hint_before_get(sb, depth); |
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nr = __sbitmap_get(sb, hint); |
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update_alloc_hint_after_get(sb, depth, hint, nr); |
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return nr; |
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} |
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EXPORT_SYMBOL_GPL(sbitmap_get); |
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static int __sbitmap_get_shallow(struct sbitmap *sb, |
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unsigned int alloc_hint, |
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unsigned long shallow_depth) |
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{ |
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unsigned int i, index; |
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int nr = -1; |
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index = SB_NR_TO_INDEX(sb, alloc_hint); |
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for (i = 0; i < sb->map_nr; i++) { |
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again: |
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nr = __sbitmap_get_word(&sb->map[index].word, |
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min_t(unsigned int, |
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__map_depth(sb, index), |
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shallow_depth), |
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SB_NR_TO_BIT(sb, alloc_hint), true); |
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if (nr != -1) { |
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nr += index << sb->shift; |
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break; |
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} |
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if (sbitmap_deferred_clear(&sb->map[index])) |
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goto again; |
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/* Jump to next index. */ |
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index++; |
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alloc_hint = index << sb->shift; |
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if (index >= sb->map_nr) { |
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index = 0; |
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alloc_hint = 0; |
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} |
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} |
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return nr; |
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} |
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int sbitmap_get_shallow(struct sbitmap *sb, unsigned long shallow_depth) |
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{ |
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int nr; |
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unsigned int hint, depth; |
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if (WARN_ON_ONCE(unlikely(!sb->alloc_hint))) |
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return -1; |
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depth = READ_ONCE(sb->depth); |
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hint = update_alloc_hint_before_get(sb, depth); |
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nr = __sbitmap_get_shallow(sb, hint, shallow_depth); |
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update_alloc_hint_after_get(sb, depth, hint, nr); |
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return nr; |
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} |
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EXPORT_SYMBOL_GPL(sbitmap_get_shallow); |
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bool sbitmap_any_bit_set(const struct sbitmap *sb) |
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{ |
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unsigned int i; |
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for (i = 0; i < sb->map_nr; i++) { |
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if (sb->map[i].word & ~sb->map[i].cleared) |
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return true; |
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} |
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return false; |
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} |
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EXPORT_SYMBOL_GPL(sbitmap_any_bit_set); |
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static unsigned int __sbitmap_weight(const struct sbitmap *sb, bool set) |
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{ |
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unsigned int i, weight = 0; |
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for (i = 0; i < sb->map_nr; i++) { |
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const struct sbitmap_word *word = &sb->map[i]; |
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unsigned int word_depth = __map_depth(sb, i); |
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if (set) |
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weight += bitmap_weight(&word->word, word_depth); |
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else |
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weight += bitmap_weight(&word->cleared, word_depth); |
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} |
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return weight; |
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} |
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static unsigned int sbitmap_cleared(const struct sbitmap *sb) |
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{ |
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return __sbitmap_weight(sb, false); |
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} |
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unsigned int sbitmap_weight(const struct sbitmap *sb) |
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{ |
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return __sbitmap_weight(sb, true) - sbitmap_cleared(sb); |
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} |
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EXPORT_SYMBOL_GPL(sbitmap_weight); |
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void sbitmap_show(struct sbitmap *sb, struct seq_file *m) |
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{ |
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seq_printf(m, "depth=%u\n", sb->depth); |
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seq_printf(m, "busy=%u\n", sbitmap_weight(sb)); |
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seq_printf(m, "cleared=%u\n", sbitmap_cleared(sb)); |
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seq_printf(m, "bits_per_word=%u\n", 1U << sb->shift); |
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seq_printf(m, "map_nr=%u\n", sb->map_nr); |
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} |
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EXPORT_SYMBOL_GPL(sbitmap_show); |
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static inline void emit_byte(struct seq_file *m, unsigned int offset, u8 byte) |
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{ |
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if ((offset & 0xf) == 0) { |
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if (offset != 0) |
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seq_putc(m, '\n'); |
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seq_printf(m, "%08x:", offset); |
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} |
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if ((offset & 0x1) == 0) |
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seq_putc(m, ' '); |
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seq_printf(m, "%02x", byte); |
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} |
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void sbitmap_bitmap_show(struct sbitmap *sb, struct seq_file *m) |
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{ |
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u8 byte = 0; |
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unsigned int byte_bits = 0; |
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unsigned int offset = 0; |
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int i; |
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for (i = 0; i < sb->map_nr; i++) { |
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unsigned long word = READ_ONCE(sb->map[i].word); |
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unsigned long cleared = READ_ONCE(sb->map[i].cleared); |
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unsigned int word_bits = __map_depth(sb, i); |
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word &= ~cleared; |
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while (word_bits > 0) { |
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unsigned int bits = min(8 - byte_bits, word_bits); |
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byte |= (word & (BIT(bits) - 1)) << byte_bits; |
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byte_bits += bits; |
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if (byte_bits == 8) { |
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emit_byte(m, offset, byte); |
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byte = 0; |
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byte_bits = 0; |
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offset++; |
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} |
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word >>= bits; |
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word_bits -= bits; |
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} |
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} |
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if (byte_bits) { |
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emit_byte(m, offset, byte); |
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offset++; |
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} |
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if (offset) |
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seq_putc(m, '\n'); |
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} |
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EXPORT_SYMBOL_GPL(sbitmap_bitmap_show); |
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static unsigned int sbq_calc_wake_batch(struct sbitmap_queue *sbq, |
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unsigned int depth) |
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{ |
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unsigned int wake_batch; |
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unsigned int shallow_depth; |
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/* |
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* For each batch, we wake up one queue. We need to make sure that our |
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* batch size is small enough that the full depth of the bitmap, |
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* potentially limited by a shallow depth, is enough to wake up all of |
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* the queues. |
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* |
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* Each full word of the bitmap has bits_per_word bits, and there might |
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* be a partial word. There are depth / bits_per_word full words and |
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* depth % bits_per_word bits left over. In bitwise arithmetic: |
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* |
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* bits_per_word = 1 << shift |
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* depth / bits_per_word = depth >> shift |
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* depth % bits_per_word = depth & ((1 << shift) - 1) |
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* |
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* Each word can be limited to sbq->min_shallow_depth bits. |
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*/ |
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shallow_depth = min(1U << sbq->sb.shift, sbq->min_shallow_depth); |
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depth = ((depth >> sbq->sb.shift) * shallow_depth + |
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min(depth & ((1U << sbq->sb.shift) - 1), shallow_depth)); |
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wake_batch = clamp_t(unsigned int, depth / SBQ_WAIT_QUEUES, 1, |
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SBQ_WAKE_BATCH); |
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return wake_batch; |
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} |
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int sbitmap_queue_init_node(struct sbitmap_queue *sbq, unsigned int depth, |
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int shift, bool round_robin, gfp_t flags, int node) |
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{ |
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int ret; |
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int i; |
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ret = sbitmap_init_node(&sbq->sb, depth, shift, flags, node, |
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round_robin, true); |
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if (ret) |
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return ret; |
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sbq->min_shallow_depth = UINT_MAX; |
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sbq->wake_batch = sbq_calc_wake_batch(sbq, depth); |
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atomic_set(&sbq->wake_index, 0); |
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atomic_set(&sbq->ws_active, 0); |
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sbq->ws = kzalloc_node(SBQ_WAIT_QUEUES * sizeof(*sbq->ws), flags, node); |
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if (!sbq->ws) { |
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sbitmap_free(&sbq->sb); |
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return -ENOMEM; |
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} |
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for (i = 0; i < SBQ_WAIT_QUEUES; i++) { |
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init_waitqueue_head(&sbq->ws[i].wait); |
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atomic_set(&sbq->ws[i].wait_cnt, sbq->wake_batch); |
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} |
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return 0; |
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} |
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EXPORT_SYMBOL_GPL(sbitmap_queue_init_node); |
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static inline void __sbitmap_queue_update_wake_batch(struct sbitmap_queue *sbq, |
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unsigned int wake_batch) |
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{ |
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int i; |
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if (sbq->wake_batch != wake_batch) { |
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WRITE_ONCE(sbq->wake_batch, wake_batch); |
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/* |
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* Pairs with the memory barrier in sbitmap_queue_wake_up() |
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* to ensure that the batch size is updated before the wait |
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* counts. |
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*/ |
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smp_mb(); |
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for (i = 0; i < SBQ_WAIT_QUEUES; i++) |
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atomic_set(&sbq->ws[i].wait_cnt, 1); |
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} |
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} |
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static void sbitmap_queue_update_wake_batch(struct sbitmap_queue *sbq, |
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unsigned int depth) |
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{ |
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unsigned int wake_batch; |
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wake_batch = sbq_calc_wake_batch(sbq, depth); |
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__sbitmap_queue_update_wake_batch(sbq, wake_batch); |
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} |
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void sbitmap_queue_recalculate_wake_batch(struct sbitmap_queue *sbq, |
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unsigned int users) |
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{ |
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unsigned int wake_batch; |
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unsigned int min_batch; |
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unsigned int depth = (sbq->sb.depth + users - 1) / users; |
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min_batch = sbq->sb.depth >= (4 * SBQ_WAIT_QUEUES) ? 4 : 1; |
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wake_batch = clamp_val(depth / SBQ_WAIT_QUEUES, |
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min_batch, SBQ_WAKE_BATCH); |
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__sbitmap_queue_update_wake_batch(sbq, wake_batch); |
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} |
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EXPORT_SYMBOL_GPL(sbitmap_queue_recalculate_wake_batch); |
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void sbitmap_queue_resize(struct sbitmap_queue *sbq, unsigned int depth) |
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{ |
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sbitmap_queue_update_wake_batch(sbq, depth); |
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sbitmap_resize(&sbq->sb, depth); |
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} |
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EXPORT_SYMBOL_GPL(sbitmap_queue_resize); |
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int __sbitmap_queue_get(struct sbitmap_queue *sbq) |
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{ |
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return sbitmap_get(&sbq->sb); |
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} |
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EXPORT_SYMBOL_GPL(__sbitmap_queue_get); |
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unsigned long __sbitmap_queue_get_batch(struct sbitmap_queue *sbq, int nr_tags, |
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unsigned int *offset) |
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{ |
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struct sbitmap *sb = &sbq->sb; |
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unsigned int hint, depth; |
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unsigned long index, nr; |
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int i; |
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if (unlikely(sb->round_robin)) |
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return 0; |
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depth = READ_ONCE(sb->depth); |
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hint = update_alloc_hint_before_get(sb, depth); |
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index = SB_NR_TO_INDEX(sb, hint); |
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for (i = 0; i < sb->map_nr; i++) { |
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struct sbitmap_word *map = &sb->map[index]; |
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unsigned long get_mask; |
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unsigned int map_depth = __map_depth(sb, index); |
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sbitmap_deferred_clear(map); |
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if (map->word == (1UL << (map_depth - 1)) - 1) |
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continue; |
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nr = find_first_zero_bit(&map->word, map_depth); |
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if (nr + nr_tags <= map_depth) { |
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atomic_long_t *ptr = (atomic_long_t *) &map->word; |
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int map_tags = min_t(int, nr_tags, map_depth); |
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unsigned long val, ret; |
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get_mask = ((1UL << map_tags) - 1) << nr; |
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do { |
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val = READ_ONCE(map->word); |
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ret = atomic_long_cmpxchg(ptr, val, get_mask | val); |
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} while (ret != val); |
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get_mask = (get_mask & ~ret) >> nr; |
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if (get_mask) { |
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*offset = nr + (index << sb->shift); |
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update_alloc_hint_after_get(sb, depth, hint, |
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*offset + map_tags - 1); |
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return get_mask; |
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} |
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} |
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/* Jump to next index. */ |
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if (++index >= sb->map_nr) |
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index = 0; |
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} |
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return 0; |
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} |
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int sbitmap_queue_get_shallow(struct sbitmap_queue *sbq, |
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unsigned int shallow_depth) |
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{ |
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WARN_ON_ONCE(shallow_depth < sbq->min_shallow_depth); |
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return sbitmap_get_shallow(&sbq->sb, shallow_depth); |
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} |
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EXPORT_SYMBOL_GPL(sbitmap_queue_get_shallow); |
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|
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void sbitmap_queue_min_shallow_depth(struct sbitmap_queue *sbq, |
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unsigned int min_shallow_depth) |
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{ |
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sbq->min_shallow_depth = min_shallow_depth; |
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sbitmap_queue_update_wake_batch(sbq, sbq->sb.depth); |
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} |
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EXPORT_SYMBOL_GPL(sbitmap_queue_min_shallow_depth); |
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static struct sbq_wait_state *sbq_wake_ptr(struct sbitmap_queue *sbq) |
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{ |
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int i, wake_index; |
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|
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if (!atomic_read(&sbq->ws_active)) |
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return NULL; |
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wake_index = atomic_read(&sbq->wake_index); |
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for (i = 0; i < SBQ_WAIT_QUEUES; i++) { |
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struct sbq_wait_state *ws = &sbq->ws[wake_index]; |
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|
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if (waitqueue_active(&ws->wait)) { |
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if (wake_index != atomic_read(&sbq->wake_index)) |
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atomic_set(&sbq->wake_index, wake_index); |
|
return ws; |
|
} |
|
|
|
wake_index = sbq_index_inc(wake_index); |
|
} |
|
|
|
return NULL; |
|
} |
|
|
|
static bool __sbq_wake_up(struct sbitmap_queue *sbq) |
|
{ |
|
struct sbq_wait_state *ws; |
|
unsigned int wake_batch; |
|
int wait_cnt; |
|
|
|
ws = sbq_wake_ptr(sbq); |
|
if (!ws) |
|
return false; |
|
|
|
wait_cnt = atomic_dec_return(&ws->wait_cnt); |
|
if (wait_cnt <= 0) { |
|
int ret; |
|
|
|
wake_batch = READ_ONCE(sbq->wake_batch); |
|
|
|
/* |
|
* Pairs with the memory barrier in sbitmap_queue_resize() to |
|
* ensure that we see the batch size update before the wait |
|
* count is reset. |
|
*/ |
|
smp_mb__before_atomic(); |
|
|
|
/* |
|
* For concurrent callers of this, the one that failed the |
|
* atomic_cmpxhcg() race should call this function again |
|
* to wakeup a new batch on a different 'ws'. |
|
*/ |
|
ret = atomic_cmpxchg(&ws->wait_cnt, wait_cnt, wake_batch); |
|
if (ret == wait_cnt) { |
|
sbq_index_atomic_inc(&sbq->wake_index); |
|
wake_up_nr(&ws->wait, wake_batch); |
|
return false; |
|
} |
|
|
|
return true; |
|
} |
|
|
|
return false; |
|
} |
|
|
|
void sbitmap_queue_wake_up(struct sbitmap_queue *sbq) |
|
{ |
|
while (__sbq_wake_up(sbq)) |
|
; |
|
} |
|
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); |
|
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); |
|
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_cnt=%d, .wait=%s},\n", |
|
atomic_read(&ws->wait_cnt), |
|
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);
|
|
|