kernel: Move GPL'd kernel files to sys/gnu to have them all in one place.
[dragonfly.git] / sys / gnu / vfs / ext2fs / ext2_bitops.h
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1/*-
2 * Copyright (c) 2003 Marcel Moolenaar
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 *
26 * $FreeBSD: src/sys/gnu/fs/ext2fs/ext2_bitops.h,v 1.3 2006/04/13 19:37:32 cracauer Exp $
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27 */
28
29#ifndef _SYS_GNU_EXT2FS_EXT2_BITOPS_H_
30#define _SYS_GNU_EXT2FS_EXT2_BITOPS_H_
31
32#define find_first_zero_bit(data, sz) find_next_zero_bit(data, sz, 0)
33
34static __inline int
35clear_bit(int no, void *data)
36{
37 uint32_t *p;
38 uint32_t mask, new, old;
39
40 p = (uint32_t*)data + (no >> 5);
41 mask = (1U << (no & 31));
42 do {
43 old = *p;
44 new = old & ~mask;
45 } while (!atomic_cmpset_32(p, old, new));
46 return (old & mask);
47}
48
49static __inline int
50set_bit(int no, void *data)
51{
52 uint32_t *p;
53 uint32_t mask, new, old;
54
55 p = (uint32_t*)data + (no >> 5);
56 mask = (1U << (no & 31));
57 do {
58 old = *p;
59 new = old | mask;
60 } while (!atomic_cmpset_32(p, old, new));
61 return (old & mask);
62}
63
64static __inline int
65test_bit(int no, void *data)
66{
67 uint32_t *p;
68 uint32_t mask;
69
70 p = (uint32_t*)data + (no >> 5);
71 mask = (1U << (no & 31));
72 return (*p & mask);
73}
74
75static __inline size_t
76find_next_zero_bit(void *data, size_t sz, size_t ofs)
77{
78 uint32_t *p;
79 uint32_t mask;
80 int bit;
81
82 p = (uint32_t*)data + (ofs >> 5);
83 if (ofs & 31) {
84 mask = ~0U << (ofs & 31);
85 bit = *p | ~mask;
86 if (bit != ~0U)
87 return (ffs(~bit) + ofs - 1);
88 p++;
89 ofs = (ofs + 31U) & ~31U;
90 }
91 while(ofs < sz && *p == ~0U) {
92 p++;
93 ofs += 32;
94 }
95 if (ofs == sz)
96 return (ofs);
97 bit = *p;
98 return (ffs(~bit) + ofs - 1);
99}
100
101static __inline void *
102memscan(void *data, int c, size_t sz)
103{
104 uint8_t *p;
105
106 p = data;
107 while (sz && *p != c) {
108 p++;
109 sz--;
110 }
111 return (p);
112}
113
114#endif /* _SYS_GNU_EXT2FS_EXT2_BITOPS_H_ */