10fc479b1SThomas Gleixner // SPDX-License-Identifier: GPL-2.0-only 288459642SOmar Sandoval /* 388459642SOmar Sandoval * Copyright (C) 2016 Facebook 488459642SOmar Sandoval * Copyright (C) 2013-2014 Jens Axboe 588459642SOmar Sandoval */ 688459642SOmar Sandoval 7af8601adSIngo Molnar #include <linux/sched.h> 898d95416SOmar Sandoval #include <linux/random.h> 988459642SOmar Sandoval #include <linux/sbitmap.h> 1024af1ccfSOmar Sandoval #include <linux/seq_file.h> 1188459642SOmar Sandoval 12c548e62bSMing Lei static int init_alloc_hint(struct sbitmap *sb, gfp_t flags) 13bf2c4282SMing Lei { 14c548e62bSMing Lei unsigned depth = sb->depth; 15bf2c4282SMing Lei 16c548e62bSMing Lei sb->alloc_hint = alloc_percpu_gfp(unsigned int, flags); 17c548e62bSMing Lei if (!sb->alloc_hint) 18bf2c4282SMing Lei return -ENOMEM; 19bf2c4282SMing Lei 20c548e62bSMing Lei if (depth && !sb->round_robin) { 21bf2c4282SMing Lei int i; 22bf2c4282SMing Lei 23bf2c4282SMing Lei for_each_possible_cpu(i) 248032bf12SJason A. Donenfeld *per_cpu_ptr(sb->alloc_hint, i) = get_random_u32_below(depth); 25bf2c4282SMing Lei } 26bf2c4282SMing Lei return 0; 27bf2c4282SMing Lei } 28bf2c4282SMing Lei 29c548e62bSMing Lei static inline unsigned update_alloc_hint_before_get(struct sbitmap *sb, 30bf2c4282SMing Lei unsigned int depth) 31bf2c4282SMing Lei { 32bf2c4282SMing Lei unsigned hint; 33bf2c4282SMing Lei 34c548e62bSMing Lei hint = this_cpu_read(*sb->alloc_hint); 35bf2c4282SMing Lei if (unlikely(hint >= depth)) { 368032bf12SJason A. Donenfeld hint = depth ? get_random_u32_below(depth) : 0; 37c548e62bSMing Lei this_cpu_write(*sb->alloc_hint, hint); 38bf2c4282SMing Lei } 39bf2c4282SMing Lei 40bf2c4282SMing Lei return hint; 41bf2c4282SMing Lei } 42bf2c4282SMing Lei 43c548e62bSMing Lei static inline void update_alloc_hint_after_get(struct sbitmap *sb, 44bf2c4282SMing Lei unsigned int depth, 45bf2c4282SMing Lei unsigned int hint, 46bf2c4282SMing Lei unsigned int nr) 47bf2c4282SMing Lei { 48bf2c4282SMing Lei if (nr == -1) { 49bf2c4282SMing Lei /* If the map is full, a hint won't do us much good. */ 50c548e62bSMing Lei this_cpu_write(*sb->alloc_hint, 0); 51c548e62bSMing Lei } else if (nr == hint || unlikely(sb->round_robin)) { 52bf2c4282SMing Lei /* Only update the hint if we used it. */ 53bf2c4282SMing Lei hint = nr + 1; 54bf2c4282SMing Lei if (hint >= depth - 1) 55bf2c4282SMing Lei hint = 0; 56c548e62bSMing Lei this_cpu_write(*sb->alloc_hint, hint); 57bf2c4282SMing Lei } 58bf2c4282SMing Lei } 59bf2c4282SMing Lei 60b2dbff1bSJens Axboe /* 61b2dbff1bSJens Axboe * See if we have deferred clears that we can batch move 62b2dbff1bSJens Axboe */ 63b78beea0SPavel Begunkov static inline bool sbitmap_deferred_clear(struct sbitmap_word *map) 64b2dbff1bSJens Axboe { 65c3250c8dSPavel Begunkov unsigned long mask; 66b2dbff1bSJens Axboe 67661d4f55SPavel Begunkov if (!READ_ONCE(map->cleared)) 68661d4f55SPavel Begunkov return false; 69b2dbff1bSJens Axboe 70b2dbff1bSJens Axboe /* 71b2dbff1bSJens Axboe * First get a stable cleared mask, setting the old mask to 0. 72b2dbff1bSJens Axboe */ 73b78beea0SPavel Begunkov mask = xchg(&map->cleared, 0); 74b2dbff1bSJens Axboe 75b2dbff1bSJens Axboe /* 76b2dbff1bSJens Axboe * Now clear the masked bits in our free word 77b2dbff1bSJens Axboe */ 78c3250c8dSPavel Begunkov atomic_long_andnot(mask, (atomic_long_t *)&map->word); 79c3250c8dSPavel Begunkov BUILD_BUG_ON(sizeof(atomic_long_t) != sizeof(map->word)); 80661d4f55SPavel Begunkov return true; 81b2dbff1bSJens Axboe } 82b2dbff1bSJens Axboe 8388459642SOmar Sandoval int sbitmap_init_node(struct sbitmap *sb, unsigned int depth, int shift, 84c548e62bSMing Lei gfp_t flags, int node, bool round_robin, 85c548e62bSMing Lei bool alloc_hint) 8688459642SOmar Sandoval { 8788459642SOmar Sandoval unsigned int bits_per_word; 8888459642SOmar Sandoval 892d13b1eaSMing Lei if (shift < 0) 902d13b1eaSMing Lei shift = sbitmap_calculate_shift(depth); 912d13b1eaSMing Lei 9288459642SOmar Sandoval bits_per_word = 1U << shift; 9388459642SOmar Sandoval if (bits_per_word > BITS_PER_LONG) 9488459642SOmar Sandoval return -EINVAL; 9588459642SOmar Sandoval 9688459642SOmar Sandoval sb->shift = shift; 9788459642SOmar Sandoval sb->depth = depth; 9888459642SOmar Sandoval sb->map_nr = DIV_ROUND_UP(sb->depth, bits_per_word); 99efe1f3a1SMing Lei sb->round_robin = round_robin; 10088459642SOmar Sandoval 10188459642SOmar Sandoval if (depth == 0) { 10288459642SOmar Sandoval sb->map = NULL; 10388459642SOmar Sandoval return 0; 10488459642SOmar Sandoval } 10588459642SOmar Sandoval 106c548e62bSMing Lei if (alloc_hint) { 107c548e62bSMing Lei if (init_alloc_hint(sb, flags)) 10888459642SOmar Sandoval return -ENOMEM; 109c548e62bSMing Lei } else { 110c548e62bSMing Lei sb->alloc_hint = NULL; 111c548e62bSMing Lei } 112c548e62bSMing Lei 113863a66cdSMing Lei sb->map = kvzalloc_node(sb->map_nr * sizeof(*sb->map), flags, node); 114c548e62bSMing Lei if (!sb->map) { 115c548e62bSMing Lei free_percpu(sb->alloc_hint); 116c548e62bSMing Lei return -ENOMEM; 117c548e62bSMing Lei } 11888459642SOmar Sandoval 11988459642SOmar Sandoval return 0; 12088459642SOmar Sandoval } 12188459642SOmar Sandoval EXPORT_SYMBOL_GPL(sbitmap_init_node); 12288459642SOmar Sandoval 12388459642SOmar Sandoval void sbitmap_resize(struct sbitmap *sb, unsigned int depth) 12488459642SOmar Sandoval { 12588459642SOmar Sandoval unsigned int bits_per_word = 1U << sb->shift; 12688459642SOmar Sandoval unsigned int i; 12788459642SOmar Sandoval 128b2dbff1bSJens Axboe for (i = 0; i < sb->map_nr; i++) 129b78beea0SPavel Begunkov sbitmap_deferred_clear(&sb->map[i]); 130b2dbff1bSJens Axboe 13188459642SOmar Sandoval sb->depth = depth; 13288459642SOmar Sandoval sb->map_nr = DIV_ROUND_UP(sb->depth, bits_per_word); 13388459642SOmar Sandoval } 13488459642SOmar Sandoval EXPORT_SYMBOL_GPL(sbitmap_resize); 13588459642SOmar Sandoval 136c05e6673SOmar Sandoval static int __sbitmap_get_word(unsigned long *word, unsigned long depth, 137c05e6673SOmar Sandoval unsigned int hint, bool wrap) 13888459642SOmar Sandoval { 13988459642SOmar Sandoval int nr; 14088459642SOmar Sandoval 1410eff1f1aSPavel Begunkov /* don't wrap if starting from 0 */ 1420eff1f1aSPavel Begunkov wrap = wrap && hint; 1430eff1f1aSPavel Begunkov 14488459642SOmar Sandoval while (1) { 145c05e6673SOmar Sandoval nr = find_next_zero_bit(word, depth, hint); 146c05e6673SOmar Sandoval if (unlikely(nr >= depth)) { 14788459642SOmar Sandoval /* 14888459642SOmar Sandoval * We started with an offset, and we didn't reset the 14988459642SOmar Sandoval * offset to 0 in a failure case, so start from 0 to 15088459642SOmar Sandoval * exhaust the map. 15188459642SOmar Sandoval */ 1520eff1f1aSPavel Begunkov if (hint && wrap) { 1530eff1f1aSPavel Begunkov hint = 0; 15488459642SOmar Sandoval continue; 15588459642SOmar Sandoval } 15688459642SOmar Sandoval return -1; 15788459642SOmar Sandoval } 15888459642SOmar Sandoval 1594ace53f1SOmar Sandoval if (!test_and_set_bit_lock(nr, word)) 16088459642SOmar Sandoval break; 16188459642SOmar Sandoval 16288459642SOmar Sandoval hint = nr + 1; 163c05e6673SOmar Sandoval if (hint >= depth - 1) 16488459642SOmar Sandoval hint = 0; 16588459642SOmar Sandoval } 16688459642SOmar Sandoval 16788459642SOmar Sandoval return nr; 16888459642SOmar Sandoval } 16988459642SOmar Sandoval 170ea86ea2cSJens Axboe static int sbitmap_find_bit_in_index(struct sbitmap *sb, int index, 171efe1f3a1SMing Lei unsigned int alloc_hint) 172ea86ea2cSJens Axboe { 173b78beea0SPavel Begunkov struct sbitmap_word *map = &sb->map[index]; 174ea86ea2cSJens Axboe int nr; 175ea86ea2cSJens Axboe 176ea86ea2cSJens Axboe do { 1773301bc53SMing Lei nr = __sbitmap_get_word(&map->word, __map_depth(sb, index), 1783301bc53SMing Lei alloc_hint, !sb->round_robin); 179ea86ea2cSJens Axboe if (nr != -1) 180ea86ea2cSJens Axboe break; 181b78beea0SPavel Begunkov if (!sbitmap_deferred_clear(map)) 182ea86ea2cSJens Axboe break; 183ea86ea2cSJens Axboe } while (1); 184ea86ea2cSJens Axboe 185ea86ea2cSJens Axboe return nr; 186ea86ea2cSJens Axboe } 187ea86ea2cSJens Axboe 188c548e62bSMing Lei static int __sbitmap_get(struct sbitmap *sb, unsigned int alloc_hint) 18988459642SOmar Sandoval { 19088459642SOmar Sandoval unsigned int i, index; 19188459642SOmar Sandoval int nr = -1; 19288459642SOmar Sandoval 19388459642SOmar Sandoval index = SB_NR_TO_INDEX(sb, alloc_hint); 19488459642SOmar Sandoval 19527fae429SJens Axboe /* 19627fae429SJens Axboe * Unless we're doing round robin tag allocation, just use the 19727fae429SJens Axboe * alloc_hint to find the right word index. No point in looping 19827fae429SJens Axboe * twice in find_next_zero_bit() for that case. 19927fae429SJens Axboe */ 200efe1f3a1SMing Lei if (sb->round_robin) 20127fae429SJens Axboe alloc_hint = SB_NR_TO_BIT(sb, alloc_hint); 20227fae429SJens Axboe else 20327fae429SJens Axboe alloc_hint = 0; 20427fae429SJens Axboe 20588459642SOmar Sandoval for (i = 0; i < sb->map_nr; i++) { 206efe1f3a1SMing Lei nr = sbitmap_find_bit_in_index(sb, index, alloc_hint); 20788459642SOmar Sandoval if (nr != -1) { 20888459642SOmar Sandoval nr += index << sb->shift; 20988459642SOmar Sandoval break; 21088459642SOmar Sandoval } 21188459642SOmar Sandoval 21288459642SOmar Sandoval /* Jump to next index. */ 21388459642SOmar Sandoval alloc_hint = 0; 21427fae429SJens Axboe if (++index >= sb->map_nr) 21527fae429SJens Axboe index = 0; 21688459642SOmar Sandoval } 21788459642SOmar Sandoval 21888459642SOmar Sandoval return nr; 21988459642SOmar Sandoval } 220c548e62bSMing Lei 221c548e62bSMing Lei int sbitmap_get(struct sbitmap *sb) 222c548e62bSMing Lei { 223c548e62bSMing Lei int nr; 224c548e62bSMing Lei unsigned int hint, depth; 225c548e62bSMing Lei 226c548e62bSMing Lei if (WARN_ON_ONCE(unlikely(!sb->alloc_hint))) 227c548e62bSMing Lei return -1; 228c548e62bSMing Lei 229c548e62bSMing Lei depth = READ_ONCE(sb->depth); 230c548e62bSMing Lei hint = update_alloc_hint_before_get(sb, depth); 231c548e62bSMing Lei nr = __sbitmap_get(sb, hint); 232c548e62bSMing Lei update_alloc_hint_after_get(sb, depth, hint, nr); 233c548e62bSMing Lei 234c548e62bSMing Lei return nr; 235c548e62bSMing Lei } 23688459642SOmar Sandoval EXPORT_SYMBOL_GPL(sbitmap_get); 23788459642SOmar Sandoval 238c548e62bSMing Lei static int __sbitmap_get_shallow(struct sbitmap *sb, 239c548e62bSMing Lei unsigned int alloc_hint, 240c05e6673SOmar Sandoval unsigned long shallow_depth) 241c05e6673SOmar Sandoval { 242c05e6673SOmar Sandoval unsigned int i, index; 243c05e6673SOmar Sandoval int nr = -1; 244c05e6673SOmar Sandoval 245c05e6673SOmar Sandoval index = SB_NR_TO_INDEX(sb, alloc_hint); 246*f1591a8bSKemeng Shi alloc_hint = SB_NR_TO_BIT(sb, alloc_hint); 247c05e6673SOmar Sandoval 248c05e6673SOmar Sandoval for (i = 0; i < sb->map_nr; i++) { 249b2dbff1bSJens Axboe again: 250c05e6673SOmar Sandoval nr = __sbitmap_get_word(&sb->map[index].word, 2513301bc53SMing Lei min_t(unsigned int, 2523301bc53SMing Lei __map_depth(sb, index), 2533301bc53SMing Lei shallow_depth), 254*f1591a8bSKemeng Shi alloc_hint, true); 255c05e6673SOmar Sandoval if (nr != -1) { 256c05e6673SOmar Sandoval nr += index << sb->shift; 257c05e6673SOmar Sandoval break; 258c05e6673SOmar Sandoval } 259c05e6673SOmar Sandoval 260b78beea0SPavel Begunkov if (sbitmap_deferred_clear(&sb->map[index])) 261b2dbff1bSJens Axboe goto again; 262b2dbff1bSJens Axboe 263c05e6673SOmar Sandoval /* Jump to next index. */ 264c05e6673SOmar Sandoval alloc_hint = 0; 265*f1591a8bSKemeng Shi if (++index >= sb->map_nr) 266*f1591a8bSKemeng Shi index = 0; 267c05e6673SOmar Sandoval } 268c05e6673SOmar Sandoval 269c05e6673SOmar Sandoval return nr; 270c05e6673SOmar Sandoval } 271c548e62bSMing Lei 272c548e62bSMing Lei int sbitmap_get_shallow(struct sbitmap *sb, unsigned long shallow_depth) 273c548e62bSMing Lei { 274c548e62bSMing Lei int nr; 275c548e62bSMing Lei unsigned int hint, depth; 276c548e62bSMing Lei 277c548e62bSMing Lei if (WARN_ON_ONCE(unlikely(!sb->alloc_hint))) 278c548e62bSMing Lei return -1; 279c548e62bSMing Lei 280c548e62bSMing Lei depth = READ_ONCE(sb->depth); 281c548e62bSMing Lei hint = update_alloc_hint_before_get(sb, depth); 282c548e62bSMing Lei nr = __sbitmap_get_shallow(sb, hint, shallow_depth); 283c548e62bSMing Lei update_alloc_hint_after_get(sb, depth, hint, nr); 284c548e62bSMing Lei 285c548e62bSMing Lei return nr; 286c548e62bSMing Lei } 287c05e6673SOmar Sandoval EXPORT_SYMBOL_GPL(sbitmap_get_shallow); 288c05e6673SOmar Sandoval 28988459642SOmar Sandoval bool sbitmap_any_bit_set(const struct sbitmap *sb) 29088459642SOmar Sandoval { 29188459642SOmar Sandoval unsigned int i; 29288459642SOmar Sandoval 29388459642SOmar Sandoval for (i = 0; i < sb->map_nr; i++) { 294b2dbff1bSJens Axboe if (sb->map[i].word & ~sb->map[i].cleared) 29588459642SOmar Sandoval return true; 29688459642SOmar Sandoval } 29788459642SOmar Sandoval return false; 29888459642SOmar Sandoval } 29988459642SOmar Sandoval EXPORT_SYMBOL_GPL(sbitmap_any_bit_set); 30088459642SOmar Sandoval 301ea86ea2cSJens Axboe static unsigned int __sbitmap_weight(const struct sbitmap *sb, bool set) 30288459642SOmar Sandoval { 30360658e0dSColin Ian King unsigned int i, weight = 0; 30488459642SOmar Sandoval 30588459642SOmar Sandoval for (i = 0; i < sb->map_nr; i++) { 30688459642SOmar Sandoval const struct sbitmap_word *word = &sb->map[i]; 3073301bc53SMing Lei unsigned int word_depth = __map_depth(sb, i); 30888459642SOmar Sandoval 309ea86ea2cSJens Axboe if (set) 3103301bc53SMing Lei weight += bitmap_weight(&word->word, word_depth); 311ea86ea2cSJens Axboe else 3123301bc53SMing Lei weight += bitmap_weight(&word->cleared, word_depth); 31388459642SOmar Sandoval } 31488459642SOmar Sandoval return weight; 31588459642SOmar Sandoval } 316ea86ea2cSJens Axboe 317ea86ea2cSJens Axboe static unsigned int sbitmap_cleared(const struct sbitmap *sb) 318ea86ea2cSJens Axboe { 319ea86ea2cSJens Axboe return __sbitmap_weight(sb, false); 320ea86ea2cSJens Axboe } 32188459642SOmar Sandoval 322cbb9950bSMing Lei unsigned int sbitmap_weight(const struct sbitmap *sb) 323cbb9950bSMing Lei { 324cbb9950bSMing Lei return __sbitmap_weight(sb, true) - sbitmap_cleared(sb); 325cbb9950bSMing Lei } 326cbb9950bSMing Lei EXPORT_SYMBOL_GPL(sbitmap_weight); 327cbb9950bSMing Lei 32824af1ccfSOmar Sandoval void sbitmap_show(struct sbitmap *sb, struct seq_file *m) 32924af1ccfSOmar Sandoval { 33024af1ccfSOmar Sandoval seq_printf(m, "depth=%u\n", sb->depth); 331cbb9950bSMing Lei seq_printf(m, "busy=%u\n", sbitmap_weight(sb)); 332ea86ea2cSJens Axboe seq_printf(m, "cleared=%u\n", sbitmap_cleared(sb)); 33324af1ccfSOmar Sandoval seq_printf(m, "bits_per_word=%u\n", 1U << sb->shift); 33424af1ccfSOmar Sandoval seq_printf(m, "map_nr=%u\n", sb->map_nr); 33524af1ccfSOmar Sandoval } 33624af1ccfSOmar Sandoval EXPORT_SYMBOL_GPL(sbitmap_show); 33724af1ccfSOmar Sandoval 33824af1ccfSOmar Sandoval static inline void emit_byte(struct seq_file *m, unsigned int offset, u8 byte) 33924af1ccfSOmar Sandoval { 34024af1ccfSOmar Sandoval if ((offset & 0xf) == 0) { 34124af1ccfSOmar Sandoval if (offset != 0) 34224af1ccfSOmar Sandoval seq_putc(m, '\n'); 34324af1ccfSOmar Sandoval seq_printf(m, "%08x:", offset); 34424af1ccfSOmar Sandoval } 34524af1ccfSOmar Sandoval if ((offset & 0x1) == 0) 34624af1ccfSOmar Sandoval seq_putc(m, ' '); 34724af1ccfSOmar Sandoval seq_printf(m, "%02x", byte); 34824af1ccfSOmar Sandoval } 34924af1ccfSOmar Sandoval 35024af1ccfSOmar Sandoval void sbitmap_bitmap_show(struct sbitmap *sb, struct seq_file *m) 35124af1ccfSOmar Sandoval { 35224af1ccfSOmar Sandoval u8 byte = 0; 35324af1ccfSOmar Sandoval unsigned int byte_bits = 0; 35424af1ccfSOmar Sandoval unsigned int offset = 0; 35524af1ccfSOmar Sandoval int i; 35624af1ccfSOmar Sandoval 35724af1ccfSOmar Sandoval for (i = 0; i < sb->map_nr; i++) { 35824af1ccfSOmar Sandoval unsigned long word = READ_ONCE(sb->map[i].word); 3596bf0eb55SJohn Garry unsigned long cleared = READ_ONCE(sb->map[i].cleared); 3603301bc53SMing Lei unsigned int word_bits = __map_depth(sb, i); 36124af1ccfSOmar Sandoval 3626bf0eb55SJohn Garry word &= ~cleared; 3636bf0eb55SJohn Garry 36424af1ccfSOmar Sandoval while (word_bits > 0) { 36524af1ccfSOmar Sandoval unsigned int bits = min(8 - byte_bits, word_bits); 36624af1ccfSOmar Sandoval 36724af1ccfSOmar Sandoval byte |= (word & (BIT(bits) - 1)) << byte_bits; 36824af1ccfSOmar Sandoval byte_bits += bits; 36924af1ccfSOmar Sandoval if (byte_bits == 8) { 37024af1ccfSOmar Sandoval emit_byte(m, offset, byte); 37124af1ccfSOmar Sandoval byte = 0; 37224af1ccfSOmar Sandoval byte_bits = 0; 37324af1ccfSOmar Sandoval offset++; 37424af1ccfSOmar Sandoval } 37524af1ccfSOmar Sandoval word >>= bits; 37624af1ccfSOmar Sandoval word_bits -= bits; 37724af1ccfSOmar Sandoval } 37824af1ccfSOmar Sandoval } 37924af1ccfSOmar Sandoval if (byte_bits) { 38024af1ccfSOmar Sandoval emit_byte(m, offset, byte); 38124af1ccfSOmar Sandoval offset++; 38224af1ccfSOmar Sandoval } 38324af1ccfSOmar Sandoval if (offset) 38424af1ccfSOmar Sandoval seq_putc(m, '\n'); 38524af1ccfSOmar Sandoval } 38624af1ccfSOmar Sandoval EXPORT_SYMBOL_GPL(sbitmap_bitmap_show); 38724af1ccfSOmar Sandoval 388a3275539SOmar Sandoval static unsigned int sbq_calc_wake_batch(struct sbitmap_queue *sbq, 389a3275539SOmar Sandoval unsigned int depth) 39088459642SOmar Sandoval { 39188459642SOmar Sandoval unsigned int wake_batch; 392a3275539SOmar Sandoval unsigned int shallow_depth; 39388459642SOmar Sandoval 39488459642SOmar Sandoval /* 39588459642SOmar Sandoval * For each batch, we wake up one queue. We need to make sure that our 396a3275539SOmar Sandoval * batch size is small enough that the full depth of the bitmap, 397a3275539SOmar Sandoval * potentially limited by a shallow depth, is enough to wake up all of 398a3275539SOmar Sandoval * the queues. 399a3275539SOmar Sandoval * 400a3275539SOmar Sandoval * Each full word of the bitmap has bits_per_word bits, and there might 401a3275539SOmar Sandoval * be a partial word. There are depth / bits_per_word full words and 402a3275539SOmar Sandoval * depth % bits_per_word bits left over. In bitwise arithmetic: 403a3275539SOmar Sandoval * 404a3275539SOmar Sandoval * bits_per_word = 1 << shift 405a3275539SOmar Sandoval * depth / bits_per_word = depth >> shift 406a3275539SOmar Sandoval * depth % bits_per_word = depth & ((1 << shift) - 1) 407a3275539SOmar Sandoval * 408a3275539SOmar Sandoval * Each word can be limited to sbq->min_shallow_depth bits. 40988459642SOmar Sandoval */ 410a3275539SOmar Sandoval shallow_depth = min(1U << sbq->sb.shift, sbq->min_shallow_depth); 411a3275539SOmar Sandoval depth = ((depth >> sbq->sb.shift) * shallow_depth + 412a3275539SOmar Sandoval min(depth & ((1U << sbq->sb.shift) - 1), shallow_depth)); 413a3275539SOmar Sandoval wake_batch = clamp_t(unsigned int, depth / SBQ_WAIT_QUEUES, 1, 414a3275539SOmar Sandoval SBQ_WAKE_BATCH); 41588459642SOmar Sandoval 41688459642SOmar Sandoval return wake_batch; 41788459642SOmar Sandoval } 41888459642SOmar Sandoval 41988459642SOmar Sandoval int sbitmap_queue_init_node(struct sbitmap_queue *sbq, unsigned int depth, 420f4a644dbSOmar Sandoval int shift, bool round_robin, gfp_t flags, int node) 42188459642SOmar Sandoval { 42288459642SOmar Sandoval int ret; 42388459642SOmar Sandoval int i; 42488459642SOmar Sandoval 425efe1f3a1SMing Lei ret = sbitmap_init_node(&sbq->sb, depth, shift, flags, node, 426c548e62bSMing Lei round_robin, true); 42788459642SOmar Sandoval if (ret) 42888459642SOmar Sandoval return ret; 42988459642SOmar Sandoval 430a3275539SOmar Sandoval sbq->min_shallow_depth = UINT_MAX; 431a3275539SOmar Sandoval sbq->wake_batch = sbq_calc_wake_batch(sbq, depth); 43288459642SOmar Sandoval atomic_set(&sbq->wake_index, 0); 4335d2ee712SJens Axboe atomic_set(&sbq->ws_active, 0); 4344f8126bbSGabriel Krisman Bertazi atomic_set(&sbq->completion_cnt, 0); 4354f8126bbSGabriel Krisman Bertazi atomic_set(&sbq->wakeup_cnt, 0); 43688459642SOmar Sandoval 43748e28166SOmar Sandoval sbq->ws = kzalloc_node(SBQ_WAIT_QUEUES * sizeof(*sbq->ws), flags, node); 43888459642SOmar Sandoval if (!sbq->ws) { 43988459642SOmar Sandoval sbitmap_free(&sbq->sb); 44088459642SOmar Sandoval return -ENOMEM; 44188459642SOmar Sandoval } 44288459642SOmar Sandoval 4434f8126bbSGabriel Krisman Bertazi for (i = 0; i < SBQ_WAIT_QUEUES; i++) 44488459642SOmar Sandoval init_waitqueue_head(&sbq->ws[i].wait); 445f4a644dbSOmar Sandoval 44688459642SOmar Sandoval return 0; 44788459642SOmar Sandoval } 44888459642SOmar Sandoval EXPORT_SYMBOL_GPL(sbitmap_queue_init_node); 44988459642SOmar Sandoval 450180dccb0SLaibin Qiu static void sbitmap_queue_update_wake_batch(struct sbitmap_queue *sbq, 451180dccb0SLaibin Qiu unsigned int depth) 452180dccb0SLaibin Qiu { 453180dccb0SLaibin Qiu unsigned int wake_batch; 454180dccb0SLaibin Qiu 455180dccb0SLaibin Qiu wake_batch = sbq_calc_wake_batch(sbq, depth); 4564f8126bbSGabriel Krisman Bertazi if (sbq->wake_batch != wake_batch) 4574f8126bbSGabriel Krisman Bertazi WRITE_ONCE(sbq->wake_batch, wake_batch); 458180dccb0SLaibin Qiu } 459180dccb0SLaibin Qiu 460180dccb0SLaibin Qiu void sbitmap_queue_recalculate_wake_batch(struct sbitmap_queue *sbq, 461180dccb0SLaibin Qiu unsigned int users) 462180dccb0SLaibin Qiu { 463180dccb0SLaibin Qiu unsigned int wake_batch; 46410825410SLaibin Qiu unsigned int min_batch; 46510825410SLaibin Qiu unsigned int depth = (sbq->sb.depth + users - 1) / users; 466180dccb0SLaibin Qiu 46710825410SLaibin Qiu min_batch = sbq->sb.depth >= (4 * SBQ_WAIT_QUEUES) ? 4 : 1; 46810825410SLaibin Qiu 46910825410SLaibin Qiu wake_batch = clamp_val(depth / SBQ_WAIT_QUEUES, 47010825410SLaibin Qiu min_batch, SBQ_WAKE_BATCH); 4714f8126bbSGabriel Krisman Bertazi 4724f8126bbSGabriel Krisman Bertazi WRITE_ONCE(sbq->wake_batch, wake_batch); 473180dccb0SLaibin Qiu } 474180dccb0SLaibin Qiu EXPORT_SYMBOL_GPL(sbitmap_queue_recalculate_wake_batch); 475180dccb0SLaibin Qiu 476a3275539SOmar Sandoval void sbitmap_queue_resize(struct sbitmap_queue *sbq, unsigned int depth) 477a3275539SOmar Sandoval { 478a3275539SOmar Sandoval sbitmap_queue_update_wake_batch(sbq, depth); 47988459642SOmar Sandoval sbitmap_resize(&sbq->sb, depth); 48088459642SOmar Sandoval } 48188459642SOmar Sandoval EXPORT_SYMBOL_GPL(sbitmap_queue_resize); 48288459642SOmar Sandoval 483f4a644dbSOmar Sandoval int __sbitmap_queue_get(struct sbitmap_queue *sbq) 48440aabb67SOmar Sandoval { 485c548e62bSMing Lei return sbitmap_get(&sbq->sb); 48640aabb67SOmar Sandoval } 48740aabb67SOmar Sandoval EXPORT_SYMBOL_GPL(__sbitmap_queue_get); 48840aabb67SOmar Sandoval 4899672b0d4SJens Axboe unsigned long __sbitmap_queue_get_batch(struct sbitmap_queue *sbq, int nr_tags, 4909672b0d4SJens Axboe unsigned int *offset) 4919672b0d4SJens Axboe { 4929672b0d4SJens Axboe struct sbitmap *sb = &sbq->sb; 4939672b0d4SJens Axboe unsigned int hint, depth; 4949672b0d4SJens Axboe unsigned long index, nr; 4959672b0d4SJens Axboe int i; 4969672b0d4SJens Axboe 4979672b0d4SJens Axboe if (unlikely(sb->round_robin)) 4989672b0d4SJens Axboe return 0; 4999672b0d4SJens Axboe 5009672b0d4SJens Axboe depth = READ_ONCE(sb->depth); 5019672b0d4SJens Axboe hint = update_alloc_hint_before_get(sb, depth); 5029672b0d4SJens Axboe 5039672b0d4SJens Axboe index = SB_NR_TO_INDEX(sb, hint); 5049672b0d4SJens Axboe 5059672b0d4SJens Axboe for (i = 0; i < sb->map_nr; i++) { 5069672b0d4SJens Axboe struct sbitmap_word *map = &sb->map[index]; 5079672b0d4SJens Axboe unsigned long get_mask; 5083301bc53SMing Lei unsigned int map_depth = __map_depth(sb, index); 5099672b0d4SJens Axboe 5109672b0d4SJens Axboe sbitmap_deferred_clear(map); 5113301bc53SMing Lei if (map->word == (1UL << (map_depth - 1)) - 1) 512fbb564a5Swuchi goto next; 5139672b0d4SJens Axboe 5143301bc53SMing Lei nr = find_first_zero_bit(&map->word, map_depth); 5153301bc53SMing Lei if (nr + nr_tags <= map_depth) { 5169672b0d4SJens Axboe atomic_long_t *ptr = (atomic_long_t *) &map->word; 517c35227d4SUros Bizjak unsigned long val; 5189672b0d4SJens Axboe 519ddbfc34fSLiu Song get_mask = ((1UL << nr_tags) - 1) << nr; 5209672b0d4SJens Axboe val = READ_ONCE(map->word); 521c35227d4SUros Bizjak do { 522fbb564a5Swuchi if ((val & ~get_mask) != val) 523fbb564a5Swuchi goto next; 524c35227d4SUros Bizjak } while (!atomic_long_try_cmpxchg(ptr, &val, 525c35227d4SUros Bizjak get_mask | val)); 526c35227d4SUros Bizjak get_mask = (get_mask & ~val) >> nr; 5279672b0d4SJens Axboe if (get_mask) { 5289672b0d4SJens Axboe *offset = nr + (index << sb->shift); 5299672b0d4SJens Axboe update_alloc_hint_after_get(sb, depth, hint, 530ddbfc34fSLiu Song *offset + nr_tags - 1); 5319672b0d4SJens Axboe return get_mask; 5329672b0d4SJens Axboe } 5339672b0d4SJens Axboe } 534fbb564a5Swuchi next: 5359672b0d4SJens Axboe /* Jump to next index. */ 5369672b0d4SJens Axboe if (++index >= sb->map_nr) 5379672b0d4SJens Axboe index = 0; 5389672b0d4SJens Axboe } 5399672b0d4SJens Axboe 5409672b0d4SJens Axboe return 0; 5419672b0d4SJens Axboe } 5429672b0d4SJens Axboe 5433f607293SJohn Garry int sbitmap_queue_get_shallow(struct sbitmap_queue *sbq, 544c05e6673SOmar Sandoval unsigned int shallow_depth) 545c05e6673SOmar Sandoval { 54661445b56SOmar Sandoval WARN_ON_ONCE(shallow_depth < sbq->min_shallow_depth); 54761445b56SOmar Sandoval 548c548e62bSMing Lei return sbitmap_get_shallow(&sbq->sb, shallow_depth); 549c05e6673SOmar Sandoval } 5503f607293SJohn Garry EXPORT_SYMBOL_GPL(sbitmap_queue_get_shallow); 551c05e6673SOmar Sandoval 552a3275539SOmar Sandoval void sbitmap_queue_min_shallow_depth(struct sbitmap_queue *sbq, 553a3275539SOmar Sandoval unsigned int min_shallow_depth) 554a3275539SOmar Sandoval { 555a3275539SOmar Sandoval sbq->min_shallow_depth = min_shallow_depth; 556a3275539SOmar Sandoval sbitmap_queue_update_wake_batch(sbq, sbq->sb.depth); 557a3275539SOmar Sandoval } 558a3275539SOmar Sandoval EXPORT_SYMBOL_GPL(sbitmap_queue_min_shallow_depth); 559a3275539SOmar Sandoval 56026edb30dSGabriel Krisman Bertazi static void __sbitmap_queue_wake_up(struct sbitmap_queue *sbq, int nr) 56188459642SOmar Sandoval { 56288459642SOmar Sandoval int i, wake_index; 56388459642SOmar Sandoval 5645d2ee712SJens Axboe if (!atomic_read(&sbq->ws_active)) 56526edb30dSGabriel Krisman Bertazi return; 5665d2ee712SJens Axboe 56788459642SOmar Sandoval wake_index = atomic_read(&sbq->wake_index); 56888459642SOmar Sandoval for (i = 0; i < SBQ_WAIT_QUEUES; i++) { 56988459642SOmar Sandoval struct sbq_wait_state *ws = &sbq->ws[wake_index]; 57088459642SOmar Sandoval 571976570b4SGabriel Krisman Bertazi /* 572976570b4SGabriel Krisman Bertazi * Advance the index before checking the current queue. 573976570b4SGabriel Krisman Bertazi * It improves fairness, by ensuring the queue doesn't 574976570b4SGabriel Krisman Bertazi * need to be fully emptied before trying to wake up 575976570b4SGabriel Krisman Bertazi * from the next one. 576976570b4SGabriel Krisman Bertazi */ 577976570b4SGabriel Krisman Bertazi wake_index = sbq_index_inc(wake_index); 578976570b4SGabriel Krisman Bertazi 57926edb30dSGabriel Krisman Bertazi /* 58026edb30dSGabriel Krisman Bertazi * It is sufficient to wake up at least one waiter to 58126edb30dSGabriel Krisman Bertazi * guarantee forward progress. 58226edb30dSGabriel Krisman Bertazi */ 58326edb30dSGabriel Krisman Bertazi if (waitqueue_active(&ws->wait) && 58426edb30dSGabriel Krisman Bertazi wake_up_nr(&ws->wait, nr)) 58526edb30dSGabriel Krisman Bertazi break; 58688459642SOmar Sandoval } 58788459642SOmar Sandoval 58888459642SOmar Sandoval if (wake_index != atomic_read(&sbq->wake_index)) 58988459642SOmar Sandoval atomic_set(&sbq->wake_index, wake_index); 590c854ab57SJens Axboe } 591c854ab57SJens Axboe 5924acb8341SKeith Busch void sbitmap_queue_wake_up(struct sbitmap_queue *sbq, int nr) 593c854ab57SJens Axboe { 5944f8126bbSGabriel Krisman Bertazi unsigned int wake_batch = READ_ONCE(sbq->wake_batch); 5954f8126bbSGabriel Krisman Bertazi unsigned int wakeups; 5964f8126bbSGabriel Krisman Bertazi 5974f8126bbSGabriel Krisman Bertazi if (!atomic_read(&sbq->ws_active)) 5984f8126bbSGabriel Krisman Bertazi return; 5994f8126bbSGabriel Krisman Bertazi 6004f8126bbSGabriel Krisman Bertazi atomic_add(nr, &sbq->completion_cnt); 6014f8126bbSGabriel Krisman Bertazi wakeups = atomic_read(&sbq->wakeup_cnt); 6024f8126bbSGabriel Krisman Bertazi 6034f8126bbSGabriel Krisman Bertazi do { 6044f8126bbSGabriel Krisman Bertazi if (atomic_read(&sbq->completion_cnt) - wakeups < wake_batch) 6054f8126bbSGabriel Krisman Bertazi return; 6064f8126bbSGabriel Krisman Bertazi } while (!atomic_try_cmpxchg(&sbq->wakeup_cnt, 6074f8126bbSGabriel Krisman Bertazi &wakeups, wakeups + wake_batch)); 6084f8126bbSGabriel Krisman Bertazi 60926edb30dSGabriel Krisman Bertazi __sbitmap_queue_wake_up(sbq, wake_batch); 61088459642SOmar Sandoval } 611bce1b56cSJens Axboe EXPORT_SYMBOL_GPL(sbitmap_queue_wake_up); 61288459642SOmar Sandoval 6131aec5e4aSJens Axboe static inline void sbitmap_update_cpu_hint(struct sbitmap *sb, int cpu, int tag) 6141aec5e4aSJens Axboe { 6151aec5e4aSJens Axboe if (likely(!sb->round_robin && tag < sb->depth)) 6169f8b93a7SJens Axboe data_race(*per_cpu_ptr(sb->alloc_hint, cpu) = tag); 6171aec5e4aSJens Axboe } 6181aec5e4aSJens Axboe 6191aec5e4aSJens Axboe void sbitmap_queue_clear_batch(struct sbitmap_queue *sbq, int offset, 6201aec5e4aSJens Axboe int *tags, int nr_tags) 6211aec5e4aSJens Axboe { 6221aec5e4aSJens Axboe struct sbitmap *sb = &sbq->sb; 6231aec5e4aSJens Axboe unsigned long *addr = NULL; 6241aec5e4aSJens Axboe unsigned long mask = 0; 6251aec5e4aSJens Axboe int i; 6261aec5e4aSJens Axboe 6271aec5e4aSJens Axboe smp_mb__before_atomic(); 6281aec5e4aSJens Axboe for (i = 0; i < nr_tags; i++) { 6291aec5e4aSJens Axboe const int tag = tags[i] - offset; 6301aec5e4aSJens Axboe unsigned long *this_addr; 6311aec5e4aSJens Axboe 6321aec5e4aSJens Axboe /* since we're clearing a batch, skip the deferred map */ 6331aec5e4aSJens Axboe this_addr = &sb->map[SB_NR_TO_INDEX(sb, tag)].word; 6341aec5e4aSJens Axboe if (!addr) { 6351aec5e4aSJens Axboe addr = this_addr; 6361aec5e4aSJens Axboe } else if (addr != this_addr) { 6371aec5e4aSJens Axboe atomic_long_andnot(mask, (atomic_long_t *) addr); 6381aec5e4aSJens Axboe mask = 0; 6391aec5e4aSJens Axboe addr = this_addr; 6401aec5e4aSJens Axboe } 6411aec5e4aSJens Axboe mask |= (1UL << SB_NR_TO_BIT(sb, tag)); 6421aec5e4aSJens Axboe } 6431aec5e4aSJens Axboe 6441aec5e4aSJens Axboe if (mask) 6451aec5e4aSJens Axboe atomic_long_andnot(mask, (atomic_long_t *) addr); 6461aec5e4aSJens Axboe 6471aec5e4aSJens Axboe smp_mb__after_atomic(); 6484acb8341SKeith Busch sbitmap_queue_wake_up(sbq, nr_tags); 6491aec5e4aSJens Axboe sbitmap_update_cpu_hint(&sbq->sb, raw_smp_processor_id(), 6501aec5e4aSJens Axboe tags[nr_tags - 1] - offset); 6511aec5e4aSJens Axboe } 6521aec5e4aSJens Axboe 65340aabb67SOmar Sandoval void sbitmap_queue_clear(struct sbitmap_queue *sbq, unsigned int nr, 654f4a644dbSOmar Sandoval unsigned int cpu) 65588459642SOmar Sandoval { 656e6d1fa58SMing Lei /* 657e6d1fa58SMing Lei * Once the clear bit is set, the bit may be allocated out. 658e6d1fa58SMing Lei * 6599dbbc3b9SZhen Lei * Orders READ/WRITE on the associated instance(such as request 660e6d1fa58SMing Lei * of blk_mq) by this bit for avoiding race with re-allocation, 661e6d1fa58SMing Lei * and its pair is the memory barrier implied in __sbitmap_get_word. 662e6d1fa58SMing Lei * 663e6d1fa58SMing Lei * One invariant is that the clear bit has to be zero when the bit 664e6d1fa58SMing Lei * is in use. 665e6d1fa58SMing Lei */ 666e6d1fa58SMing Lei smp_mb__before_atomic(); 667ea86ea2cSJens Axboe sbitmap_deferred_clear_bit(&sbq->sb, nr); 668ea86ea2cSJens Axboe 669e6fc4649SMing Lei /* 670e6fc4649SMing Lei * Pairs with the memory barrier in set_current_state() to ensure the 671e6fc4649SMing Lei * proper ordering of clear_bit_unlock()/waitqueue_active() in the waker 672e6fc4649SMing Lei * and test_and_set_bit_lock()/prepare_to_wait()/finish_wait() in the 673e6fc4649SMing Lei * waiter. See the comment on waitqueue_active(). 674e6fc4649SMing Lei */ 675e6fc4649SMing Lei smp_mb__after_atomic(); 6764acb8341SKeith Busch sbitmap_queue_wake_up(sbq, 1); 6771aec5e4aSJens Axboe sbitmap_update_cpu_hint(&sbq->sb, cpu, nr); 67888459642SOmar Sandoval } 67988459642SOmar Sandoval EXPORT_SYMBOL_GPL(sbitmap_queue_clear); 68088459642SOmar Sandoval 68188459642SOmar Sandoval void sbitmap_queue_wake_all(struct sbitmap_queue *sbq) 68288459642SOmar Sandoval { 68388459642SOmar Sandoval int i, wake_index; 68488459642SOmar Sandoval 68588459642SOmar Sandoval /* 686f66227deSOmar Sandoval * Pairs with the memory barrier in set_current_state() like in 687e6fc4649SMing Lei * sbitmap_queue_wake_up(). 68888459642SOmar Sandoval */ 68988459642SOmar Sandoval smp_mb(); 69088459642SOmar Sandoval wake_index = atomic_read(&sbq->wake_index); 69188459642SOmar Sandoval for (i = 0; i < SBQ_WAIT_QUEUES; i++) { 69288459642SOmar Sandoval struct sbq_wait_state *ws = &sbq->ws[wake_index]; 69388459642SOmar Sandoval 69488459642SOmar Sandoval if (waitqueue_active(&ws->wait)) 69588459642SOmar Sandoval wake_up(&ws->wait); 69688459642SOmar Sandoval 69788459642SOmar Sandoval wake_index = sbq_index_inc(wake_index); 69888459642SOmar Sandoval } 69988459642SOmar Sandoval } 70088459642SOmar Sandoval EXPORT_SYMBOL_GPL(sbitmap_queue_wake_all); 70124af1ccfSOmar Sandoval 70224af1ccfSOmar Sandoval void sbitmap_queue_show(struct sbitmap_queue *sbq, struct seq_file *m) 70324af1ccfSOmar Sandoval { 70424af1ccfSOmar Sandoval bool first; 70524af1ccfSOmar Sandoval int i; 70624af1ccfSOmar Sandoval 70724af1ccfSOmar Sandoval sbitmap_show(&sbq->sb, m); 70824af1ccfSOmar Sandoval 70924af1ccfSOmar Sandoval seq_puts(m, "alloc_hint={"); 71024af1ccfSOmar Sandoval first = true; 71124af1ccfSOmar Sandoval for_each_possible_cpu(i) { 71224af1ccfSOmar Sandoval if (!first) 71324af1ccfSOmar Sandoval seq_puts(m, ", "); 71424af1ccfSOmar Sandoval first = false; 715c548e62bSMing Lei seq_printf(m, "%u", *per_cpu_ptr(sbq->sb.alloc_hint, i)); 71624af1ccfSOmar Sandoval } 71724af1ccfSOmar Sandoval seq_puts(m, "}\n"); 71824af1ccfSOmar Sandoval 71924af1ccfSOmar Sandoval seq_printf(m, "wake_batch=%u\n", sbq->wake_batch); 72024af1ccfSOmar Sandoval seq_printf(m, "wake_index=%d\n", atomic_read(&sbq->wake_index)); 7215d2ee712SJens Axboe seq_printf(m, "ws_active=%d\n", atomic_read(&sbq->ws_active)); 72224af1ccfSOmar Sandoval 72324af1ccfSOmar Sandoval seq_puts(m, "ws={\n"); 72424af1ccfSOmar Sandoval for (i = 0; i < SBQ_WAIT_QUEUES; i++) { 72524af1ccfSOmar Sandoval struct sbq_wait_state *ws = &sbq->ws[i]; 7264f8126bbSGabriel Krisman Bertazi seq_printf(m, "\t{.wait=%s},\n", 72724af1ccfSOmar Sandoval waitqueue_active(&ws->wait) ? "active" : "inactive"); 72824af1ccfSOmar Sandoval } 72924af1ccfSOmar Sandoval seq_puts(m, "}\n"); 73024af1ccfSOmar Sandoval 731efe1f3a1SMing Lei seq_printf(m, "round_robin=%d\n", sbq->sb.round_robin); 732a3275539SOmar Sandoval seq_printf(m, "min_shallow_depth=%u\n", sbq->min_shallow_depth); 73324af1ccfSOmar Sandoval } 73424af1ccfSOmar Sandoval EXPORT_SYMBOL_GPL(sbitmap_queue_show); 7355d2ee712SJens Axboe 7369f6b7ef6SJens Axboe void sbitmap_add_wait_queue(struct sbitmap_queue *sbq, 7379f6b7ef6SJens Axboe struct sbq_wait_state *ws, 7389f6b7ef6SJens Axboe struct sbq_wait *sbq_wait) 7399f6b7ef6SJens Axboe { 7409f6b7ef6SJens Axboe if (!sbq_wait->sbq) { 7419f6b7ef6SJens Axboe sbq_wait->sbq = sbq; 7429f6b7ef6SJens Axboe atomic_inc(&sbq->ws_active); 7439f6b7ef6SJens Axboe add_wait_queue(&ws->wait, &sbq_wait->wait); 7449f6b7ef6SJens Axboe } 745df034c93SDavid Jeffery } 7469f6b7ef6SJens Axboe EXPORT_SYMBOL_GPL(sbitmap_add_wait_queue); 7479f6b7ef6SJens Axboe 7489f6b7ef6SJens Axboe void sbitmap_del_wait_queue(struct sbq_wait *sbq_wait) 7499f6b7ef6SJens Axboe { 7509f6b7ef6SJens Axboe list_del_init(&sbq_wait->wait.entry); 7519f6b7ef6SJens Axboe if (sbq_wait->sbq) { 7529f6b7ef6SJens Axboe atomic_dec(&sbq_wait->sbq->ws_active); 7539f6b7ef6SJens Axboe sbq_wait->sbq = NULL; 7549f6b7ef6SJens Axboe } 7559f6b7ef6SJens Axboe } 7569f6b7ef6SJens Axboe EXPORT_SYMBOL_GPL(sbitmap_del_wait_queue); 7579f6b7ef6SJens Axboe 7585d2ee712SJens Axboe void sbitmap_prepare_to_wait(struct sbitmap_queue *sbq, 7595d2ee712SJens Axboe struct sbq_wait_state *ws, 7605d2ee712SJens Axboe struct sbq_wait *sbq_wait, int state) 7615d2ee712SJens Axboe { 7629f6b7ef6SJens Axboe if (!sbq_wait->sbq) { 7635d2ee712SJens Axboe atomic_inc(&sbq->ws_active); 7649f6b7ef6SJens Axboe sbq_wait->sbq = sbq; 7655d2ee712SJens Axboe } 7665d2ee712SJens Axboe prepare_to_wait_exclusive(&ws->wait, &sbq_wait->wait, state); 7675d2ee712SJens Axboe } 7685d2ee712SJens Axboe EXPORT_SYMBOL_GPL(sbitmap_prepare_to_wait); 7695d2ee712SJens Axboe 7705d2ee712SJens Axboe void sbitmap_finish_wait(struct sbitmap_queue *sbq, struct sbq_wait_state *ws, 7715d2ee712SJens Axboe struct sbq_wait *sbq_wait) 7725d2ee712SJens Axboe { 7735d2ee712SJens Axboe finish_wait(&ws->wait, &sbq_wait->wait); 7749f6b7ef6SJens Axboe if (sbq_wait->sbq) { 7755d2ee712SJens Axboe atomic_dec(&sbq->ws_active); 7769f6b7ef6SJens Axboe sbq_wait->sbq = NULL; 7775d2ee712SJens Axboe } 7785d2ee712SJens Axboe } 7795d2ee712SJens Axboe EXPORT_SYMBOL_GPL(sbitmap_finish_wait); 780