bitops.c revision 65f0aab98b20b5994a726ab90d355248bcddfffd 
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 <stdio.h>
14#if HAVE_SYS_TYPES_H
15#include <sys/types.h>
16#endif
17
18#include "ext2_fs.h"
19#include "ext2fs.h"
20
21#ifndef _EXT2_HAVE_ASM_BITOPS_
22
23/*
24 * For the benefit of those who are trying to port Linux to another
25 * architecture, here are some C-language equivalents.  You should
26 * recode these in the native assmebly language, if at all possible.
27 *
28 * C language equivalents written by Theodore Ts'o, 9/26/92.
29 * Modified by Pete A. Zaitcev 7/14/95 to be portable to big endian
30 * systems, as well as non-32 bit systems.
31 */
32
33int ext2fs_set_bit(unsigned int nr,void * addr)
34{
35	int		mask, retval;
36	unsigned char	*ADDR = (unsigned char *) addr;
37
38	ADDR += nr >> 3;
39	mask = 1 << (nr & 0x07);
40	retval = mask & *ADDR;
41	*ADDR |= mask;
42	return retval;
43}
44
45int ext2fs_clear_bit(unsigned int nr, void * addr)
46{
47	int		mask, retval;
48	unsigned char	*ADDR = (unsigned char *) addr;
49
50	ADDR += nr >> 3;
51	mask = 1 << (nr & 0x07);
52	retval = mask & *ADDR;
53	*ADDR &= ~mask;
54	return retval;
55}
56
57int ext2fs_test_bit(unsigned int nr, const void * addr)
58{
59	int			mask;
60	const unsigned char	*ADDR = (const unsigned char *) addr;
61
62	ADDR += nr >> 3;
63	mask = 1 << (nr & 0x07);
64	return (mask & *ADDR);
65}
66
67#endif	/* !_EXT2_HAVE_ASM_BITOPS_ */
68
69void ext2fs_warn_bitmap(errcode_t errcode, unsigned long arg,
70			const char *description)
71{
72#ifndef OMIT_COM_ERR
73	if (description)
74		com_err(0, errcode, "#%lu for %s", arg, description);
75	else
76		com_err(0, errcode, "#%lu", arg);
77#endif
78}
79