1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
|
/*
* bitops.c --- Bitmap frobbing code. See bitops.h for the inlined
* routines.
*
* Copyright (C) 1993, 1994, 1995, 1996 Theodore Ts'o.
*
* %Begin-Header%
* This file may be redistributed under the terms of the GNU Library
* General Public License, version 2.
* %End-Header%
*/
#include "config.h"
#include <stdio.h>
#if HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#include "ext2_fs.h"
#include "ext2fs.h"
/*
* C language bitmap functions written by Theodore Ts'o, 9/26/92.
* Modified by Pete A. Zaitcev 7/14/95 to be portable to big endian
* systems, as well as non-32 bit systems.
*/
int ext2fs_set_bit(unsigned int nr,void * addr)
{
int mask, retval;
unsigned char *ADDR = (unsigned char *) addr;
ADDR += nr >> 3;
mask = 1 << (nr & 0x07);
retval = mask & *ADDR;
*ADDR |= mask;
return retval;
}
int ext2fs_clear_bit(unsigned int nr, void * addr)
{
int mask, retval;
unsigned char *ADDR = (unsigned char *) addr;
ADDR += nr >> 3;
mask = 1 << (nr & 0x07);
retval = mask & *ADDR;
*ADDR &= ~mask;
return retval;
}
int ext2fs_test_bit(unsigned int nr, const void * addr)
{
int mask;
const unsigned char *ADDR = (const unsigned char *) addr;
ADDR += nr >> 3;
mask = 1 << (nr & 0x07);
return (mask & *ADDR);
}
void ext2fs_warn_bitmap(errcode_t errcode, unsigned long arg,
const char *description)
{
#ifndef OMIT_COM_ERR
if (description)
com_err(0, errcode, "#%lu for %s", arg, description);
else
com_err(0, errcode, "#%lu", arg);
#endif
}
/* Bitmap functions that take a 64-bit offset */
int ext2fs_set_bit64(__u64 nr, void * addr)
{
int mask, retval;
unsigned char *ADDR = (unsigned char *) addr;
ADDR += nr >> 3;
mask = 1 << (nr & 0x07);
retval = mask & *ADDR;
*ADDR |= mask;
return retval;
}
int ext2fs_clear_bit64(__u64 nr, void * addr)
{
int mask, retval;
unsigned char *ADDR = (unsigned char *) addr;
ADDR += nr >> 3;
mask = 1 << (nr & 0x07);
retval = mask & *ADDR;
*ADDR &= ~mask;
return retval;
}
int ext2fs_test_bit64(__u64 nr, const void * addr)
{
int mask;
const unsigned char *ADDR = (const unsigned char *) addr;
ADDR += nr >> 3;
mask = 1 << (nr & 0x07);
return (mask & *ADDR);
}
static unsigned int popcount8(unsigned int w)
{
unsigned int res = w - ((w >> 1) & 0x55);
res = (res & 0x33) + ((res >> 2) & 0x33);
return (res + (res >> 4)) & 0x0F;
}
static unsigned int popcount32(unsigned int w)
{
unsigned int res = w - ((w >> 1) & 0x55555555);
res = (res & 0x33333333) + ((res >> 2) & 0x33333333);
res = (res + (res >> 4)) & 0x0F0F0F0F;
res = res + (res >> 8);
return (res + (res >> 16)) & 0x000000FF;
}
unsigned int ext2fs_bitcount(const void *addr, unsigned int nbytes)
{
const unsigned char *cp = addr;
const __u32 *p;
unsigned int res = 0;
while (((((uintptr_t) cp) & 3) != 0) && (nbytes > 0)) {
res += popcount8(*cp++);
nbytes--;
}
p = (const __u32 *) cp;
while (nbytes > 4) {
res += popcount32(*p++);
nbytes -= 4;
}
cp = (const unsigned char *) p;
while (nbytes > 0) {
res += popcount8(*cp++);
nbytes--;
}
return res;
}
|
