bitops.h
5.84 KB
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
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
/*
* Copyright 1995, Russell King.
*
* Based on the arm32 version by RMK (and others). Their copyrights apply to
* Those parts.
* Modified for arm26 by Ian Molton on 25/11/04
*
* bit 0 is the LSB of an "unsigned long" quantity.
*
* Please note that the code in this file should never be included
* from user space. Many of these are not implemented in assembler
* since they would be too costly. Also, they require privileged
* instructions (which are not available from user mode) to ensure
* that they are atomic.
*/
#ifndef __ASM_ARM_BITOPS_H
#define __ASM_ARM_BITOPS_H
#ifdef __KERNEL__
#include <linux/compiler.h>
#include <asm/system.h>
#define smp_mb__before_clear_bit() do { } while (0)
#define smp_mb__after_clear_bit() do { } while (0)
/*
* These functions are the basis of our bit ops.
*
* First, the atomic bitops. These use native endian.
*/
static inline void ____atomic_set_bit(unsigned int bit, volatile unsigned long *p)
{
unsigned long flags;
unsigned long mask = 1UL << (bit & 31);
p += bit >> 5;
local_irq_save(flags);
*p |= mask;
local_irq_restore(flags);
}
static inline void ____atomic_clear_bit(unsigned int bit, volatile unsigned long *p)
{
unsigned long flags;
unsigned long mask = 1UL << (bit & 31);
p += bit >> 5;
local_irq_save(flags);
*p &= ~mask;
local_irq_restore(flags);
}
static inline void ____atomic_change_bit(unsigned int bit, volatile unsigned long *p)
{
unsigned long flags;
unsigned long mask = 1UL << (bit & 31);
p += bit >> 5;
local_irq_save(flags);
*p ^= mask;
local_irq_restore(flags);
}
static inline int
____atomic_test_and_set_bit(unsigned int bit, volatile unsigned long *p)
{
unsigned long flags;
unsigned int res;
unsigned long mask = 1UL << (bit & 31);
p += bit >> 5;
local_irq_save(flags);
res = *p;
*p = res | mask;
local_irq_restore(flags);
return res & mask;
}
static inline int
____atomic_test_and_clear_bit(unsigned int bit, volatile unsigned long *p)
{
unsigned long flags;
unsigned int res;
unsigned long mask = 1UL << (bit & 31);
p += bit >> 5;
local_irq_save(flags);
res = *p;
*p = res & ~mask;
local_irq_restore(flags);
return res & mask;
}
static inline int
____atomic_test_and_change_bit(unsigned int bit, volatile unsigned long *p)
{
unsigned long flags;
unsigned int res;
unsigned long mask = 1UL << (bit & 31);
p += bit >> 5;
local_irq_save(flags);
res = *p;
*p = res ^ mask;
local_irq_restore(flags);
return res & mask;
}
#include <asm-generic/bitops/non-atomic.h>
/*
* Little endian assembly bitops. nr = 0 -> byte 0 bit 0.
*/
extern void _set_bit_le(int nr, volatile unsigned long * p);
extern void _clear_bit_le(int nr, volatile unsigned long * p);
extern void _change_bit_le(int nr, volatile unsigned long * p);
extern int _test_and_set_bit_le(int nr, volatile unsigned long * p);
extern int _test_and_clear_bit_le(int nr, volatile unsigned long * p);
extern int _test_and_change_bit_le(int nr, volatile unsigned long * p);
extern int _find_first_zero_bit_le(const unsigned long * p, unsigned size);
extern int _find_next_zero_bit_le(void * p, int size, int offset);
extern int _find_first_bit_le(const unsigned long *p, unsigned size);
extern int _find_next_bit_le(const unsigned long *p, int size, int offset);
/*
* The __* form of bitops are non-atomic and may be reordered.
*/
#define ATOMIC_BITOP_LE(name,nr,p) \
(__builtin_constant_p(nr) ? \
____atomic_##name(nr, p) : \
_##name##_le(nr,p))
#define NONATOMIC_BITOP(name,nr,p) \
(____nonatomic_##name(nr, p))
/*
* These are the little endian, atomic definitions.
*/
#define set_bit(nr,p) ATOMIC_BITOP_LE(set_bit,nr,p)
#define clear_bit(nr,p) ATOMIC_BITOP_LE(clear_bit,nr,p)
#define change_bit(nr,p) ATOMIC_BITOP_LE(change_bit,nr,p)
#define test_and_set_bit(nr,p) ATOMIC_BITOP_LE(test_and_set_bit,nr,p)
#define test_and_clear_bit(nr,p) ATOMIC_BITOP_LE(test_and_clear_bit,nr,p)
#define test_and_change_bit(nr,p) ATOMIC_BITOP_LE(test_and_change_bit,nr,p)
#define find_first_zero_bit(p,sz) _find_first_zero_bit_le(p,sz)
#define find_next_zero_bit(p,sz,off) _find_next_zero_bit_le(p,sz,off)
#define find_first_bit(p,sz) _find_first_bit_le(p,sz)
#define find_next_bit(p,sz,off) _find_next_bit_le(p,sz,off)
#define WORD_BITOFF_TO_LE(x) ((x))
#include <asm-generic/bitops/ffz.h>
#include <asm-generic/bitops/__ffs.h>
#include <asm-generic/bitops/fls.h>
#include <asm-generic/bitops/fls64.h>
#include <asm-generic/bitops/ffs.h>
#include <asm-generic/bitops/sched.h>
#include <asm-generic/bitops/hweight.h>
/*
* Ext2 is defined to use little-endian byte ordering.
* These do not need to be atomic.
*/
#define ext2_set_bit(nr,p) \
__test_and_set_bit(WORD_BITOFF_TO_LE(nr), (unsigned long *)(p))
#define ext2_set_bit_atomic(lock,nr,p) \
test_and_set_bit(WORD_BITOFF_TO_LE(nr), (unsigned long *)(p))
#define ext2_clear_bit(nr,p) \
__test_and_clear_bit(WORD_BITOFF_TO_LE(nr), (unsigned long *)(p))
#define ext2_clear_bit_atomic(lock,nr,p) \
test_and_clear_bit(WORD_BITOFF_TO_LE(nr), (unsigned long *)(p))
#define ext2_test_bit(nr,p) \
test_bit(WORD_BITOFF_TO_LE(nr), (unsigned long *)(p))
#define ext2_find_first_zero_bit(p,sz) \
_find_first_zero_bit_le(p,sz)
#define ext2_find_next_zero_bit(p,sz,off) \
_find_next_zero_bit_le(p,sz,off)
/*
* Minix is defined to use little-endian byte ordering.
* These do not need to be atomic.
*/
#define minix_set_bit(nr,p) \
__set_bit(WORD_BITOFF_TO_LE(nr), (unsigned long *)(p))
#define minix_test_bit(nr,p) \
test_bit(WORD_BITOFF_TO_LE(nr), (unsigned long *)(p))
#define minix_test_and_set_bit(nr,p) \
__test_and_set_bit(WORD_BITOFF_TO_LE(nr), (unsigned long *)(p))
#define minix_test_and_clear_bit(nr,p) \
__test_and_clear_bit(WORD_BITOFF_TO_LE(nr), (unsigned long *)(p))
#define minix_find_first_zero_bit(p,sz) \
_find_first_zero_bit_le((unsigned long *)(p),sz)
#endif /* __KERNEL__ */
#endif /* _ARM_BITOPS_H */