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178e776169
position of the found zero bit. Submitted by: Jaakko Heinonen <jh saunalahti fi> MFC after: 2 weeks
115 lines
2.8 KiB
C
115 lines
2.8 KiB
C
/*-
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* Copyright (c) 2003 Marcel Moolenaar
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*
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* $FreeBSD$
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*/
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#ifndef _SYS_GNU_EXT2FS_EXT2_BITOPS_H_
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#define _SYS_GNU_EXT2FS_EXT2_BITOPS_H_
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#define find_first_zero_bit(data, sz) find_next_zero_bit(data, sz, 0)
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static __inline int
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clear_bit(int no, void *data)
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{
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uint32_t *p;
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uint32_t mask, new, old;
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p = (uint32_t*)data + (no >> 5);
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mask = (1U << (no & 31));
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do {
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old = *p;
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new = old & ~mask;
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} while (!atomic_cmpset_32(p, old, new));
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return (old & mask);
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}
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static __inline int
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set_bit(int no, void *data)
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{
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uint32_t *p;
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uint32_t mask, new, old;
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p = (uint32_t*)data + (no >> 5);
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mask = (1U << (no & 31));
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do {
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old = *p;
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new = old | mask;
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} while (!atomic_cmpset_32(p, old, new));
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return (old & mask);
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}
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static __inline int
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test_bit(int no, void *data)
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{
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uint32_t *p;
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uint32_t mask;
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p = (uint32_t*)data + (no >> 5);
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mask = (1U << (no & 31));
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return (*p & mask);
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}
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static __inline size_t
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find_next_zero_bit(void *data, size_t sz, size_t ofs)
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{
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uint32_t *p;
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uint32_t mask;
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int bit;
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p = (uint32_t*)data + (ofs >> 5);
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if (ofs & 31) {
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mask = ~0U << (ofs & 31);
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bit = *p | ~mask;
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if (bit != ~0U)
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return (ffs(~bit) + (ofs & ~31U) - 1);
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p++;
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ofs = (ofs + 31U) & ~31U;
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}
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while(ofs < sz && *p == ~0U) {
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p++;
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ofs += 32;
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}
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if (ofs == sz)
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return (ofs);
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bit = *p;
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return (ffs(~bit) + ofs - 1);
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}
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static __inline void *
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memscan(void *data, int c, size_t sz)
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{
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uint8_t *p;
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p = data;
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while (sz && *p != c) {
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p++;
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sz--;
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}
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return (p);
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}
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#endif /* _SYS_GNU_EXT2FS_EXT2_BITOPS_H_ */
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