bitops.c revision d1154eb460efe588eaed3d439c1caaca149fa362 
1/*
2 * bitops.c --- Bitmap frobbing code.  See bitops.h for the inlined
3 * 	routines.
4 *
5 * Copyright (C) 1993, 1994, 1995, 1996 Theodore Ts'o.
6 *
7 * %Begin-Header%
8 * This file may be redistributed under the terms of the GNU Library
9 * General Public License, version 2.
10 * %End-Header%
11 */
12
13#include "config.h"
14#include <stdio.h>
15#if HAVE_SYS_TYPES_H
16#include <sys/types.h>
17#endif
18
19#include "ext2_fs.h"
20#include "ext2fs.h"
21
22#ifndef _EXT2_HAVE_ASM_BITOPS_
23
24/*
25 * For the benefit of those who are trying to port Linux to another
26 * architecture, here are some C-language equivalents.  You should
27 * recode these in the native assmebly language, if at all possible.
28 *
29 * C language equivalents written by Theodore Ts'o, 9/26/92.
30 * Modified by Pete A. Zaitcev 7/14/95 to be portable to big endian
31 * systems, as well as non-32 bit systems.
32 */
33
34int ext2fs_set_bit(unsigned int nr,void * addr)
35{
36	int		mask, retval;
37	unsigned char	*ADDR = (unsigned char *) addr;
38
39	ADDR += nr >> 3;
40	mask = 1 << (nr & 0x07);
41	retval = mask & *ADDR;
42	*ADDR |= mask;
43	return retval;
44}
45
46int ext2fs_clear_bit(unsigned int nr, void * addr)
47{
48	int		mask, retval;
49	unsigned char	*ADDR = (unsigned char *) addr;
50
51	ADDR += nr >> 3;
52	mask = 1 << (nr & 0x07);
53	retval = mask & *ADDR;
54	*ADDR &= ~mask;
55	return retval;
56}
57
58int ext2fs_test_bit(unsigned int nr, const void * addr)
59{
60	int			mask;
61	const unsigned char	*ADDR = (const unsigned char *) addr;
62
63	ADDR += nr >> 3;
64	mask = 1 << (nr & 0x07);
65	return (mask & *ADDR);
66}
67
68#endif	/* !_EXT2_HAVE_ASM_BITOPS_ */
69
70void ext2fs_warn_bitmap(errcode_t errcode, unsigned long arg,
71			const char *description)
72{
73#ifndef OMIT_COM_ERR
74	if (description)
75		com_err(0, errcode, "#%lu for %s", arg, description);
76	else
77		com_err(0, errcode, "#%lu", arg);
78#endif
79}
80
81/*
82 * C-only 64 bit ops.
83 */
84
85int ext2fs_set_bit64(__u64 nr, void * addr)
86{
87	int		mask, retval;
88	unsigned char	*ADDR = (unsigned char *) addr;
89
90	ADDR += nr >> 3;
91	mask = 1 << (nr & 0x07);
92	retval = mask & *ADDR;
93	*ADDR |= mask;
94	return retval;
95}
96
97int ext2fs_clear_bit64(__u64 nr, void * addr)
98{
99	int		mask, retval;
100	unsigned char	*ADDR = (unsigned char *) addr;
101
102	ADDR += nr >> 3;
103	mask = 1 << (nr & 0x07);
104	retval = mask & *ADDR;
105	*ADDR &= ~mask;
106	return retval;
107}
108
109int ext2fs_test_bit64(__u64 nr, const void * addr)
110{
111	int			mask;
112	const unsigned char	*ADDR = (const unsigned char *) addr;
113
114	ADDR += nr >> 3;
115	mask = 1 << (nr & 0x07);
116	return (mask & *ADDR);
117}
118
119