bitops.h
4.38 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
/* asm/bitops.h for Linux/CRIS
*
* TODO: asm versions if speed is needed
*
* All bit operations return 0 if the bit was cleared before the
* operation and != 0 if it was not.
*
* bit 0 is the LSB of addr; bit 32 is the LSB of (addr+1).
*/
#ifndef _CRIS_BITOPS_H
#define _CRIS_BITOPS_H
/* Currently this is unsuitable for consumption outside the kernel. */
#ifdef __KERNEL__
#include <asm/arch/bitops.h>
#include <asm/system.h>
#include <asm/atomic.h>
#include <linux/compiler.h>
/*
* Some hacks to defeat gcc over-optimizations..
*/
struct __dummy { unsigned long a[100]; };
#define ADDR (*(struct __dummy *) addr)
#define CONST_ADDR (*(const struct __dummy *) addr)
/*
* set_bit - Atomically set a bit in memory
* @nr: the bit to set
* @addr: the address to start counting from
*
* This function is atomic and may not be reordered. See __set_bit()
* if you do not require the atomic guarantees.
* Note that @nr may be almost arbitrarily large; this function is not
* restricted to acting on a single-word quantity.
*/
#define set_bit(nr, addr) (void)test_and_set_bit(nr, addr)
/*
* clear_bit - Clears a bit in memory
* @nr: Bit to clear
* @addr: Address to start counting from
*
* clear_bit() is atomic and may not be reordered. However, it does
* not contain a memory barrier, so if it is used for locking purposes,
* you should call smp_mb__before_clear_bit() and/or smp_mb__after_clear_bit()
* in order to ensure changes are visible on other processors.
*/
#define clear_bit(nr, addr) (void)test_and_clear_bit(nr, addr)
/*
* change_bit - Toggle a bit in memory
* @nr: Bit to change
* @addr: Address to start counting from
*
* change_bit() is atomic and may not be reordered.
* Note that @nr may be almost arbitrarily large; this function is not
* restricted to acting on a single-word quantity.
*/
#define change_bit(nr, addr) (void)test_and_change_bit(nr, addr)
/**
* test_and_set_bit - Set a bit and return its old value
* @nr: Bit to set
* @addr: Address to count from
*
* This operation is atomic and cannot be reordered.
* It also implies a memory barrier.
*/
static inline int test_and_set_bit(int nr, volatile unsigned long *addr)
{
unsigned int mask, retval;
unsigned long flags;
unsigned int *adr = (unsigned int *)addr;
adr += nr >> 5;
mask = 1 << (nr & 0x1f);
cris_atomic_save(addr, flags);
retval = (mask & *adr) != 0;
*adr |= mask;
cris_atomic_restore(addr, flags);
return retval;
}
/*
* clear_bit() doesn't provide any barrier for the compiler.
*/
#define smp_mb__before_clear_bit() barrier()
#define smp_mb__after_clear_bit() barrier()
/**
* test_and_clear_bit - Clear a bit and return its old value
* @nr: Bit to clear
* @addr: Address to count from
*
* This operation is atomic and cannot be reordered.
* It also implies a memory barrier.
*/
static inline int test_and_clear_bit(int nr, volatile unsigned long *addr)
{
unsigned int mask, retval;
unsigned long flags;
unsigned int *adr = (unsigned int *)addr;
adr += nr >> 5;
mask = 1 << (nr & 0x1f);
cris_atomic_save(addr, flags);
retval = (mask & *adr) != 0;
*adr &= ~mask;
cris_atomic_restore(addr, flags);
return retval;
}
/**
* test_and_change_bit - Change a bit and return its old value
* @nr: Bit to change
* @addr: Address to count from
*
* This operation is atomic and cannot be reordered.
* It also implies a memory barrier.
*/
static inline int test_and_change_bit(int nr, volatile unsigned long *addr)
{
unsigned int mask, retval;
unsigned long flags;
unsigned int *adr = (unsigned int *)addr;
adr += nr >> 5;
mask = 1 << (nr & 0x1f);
cris_atomic_save(addr, flags);
retval = (mask & *adr) != 0;
*adr ^= mask;
cris_atomic_restore(addr, flags);
return retval;
}
#include <asm-generic/bitops/non-atomic.h>
/*
* Since we define it "external", it collides with the built-in
* definition, which doesn't have the same semantics. We don't want to
* use -fno-builtin, so just hide the name ffs.
*/
#define ffs kernel_ffs
#include <asm-generic/bitops/fls.h>
#include <asm-generic/bitops/fls64.h>
#include <asm-generic/bitops/hweight.h>
#include <asm-generic/bitops/find.h>
#include <asm-generic/bitops/ext2-non-atomic.h>
#define ext2_set_bit_atomic(l,n,a) test_and_set_bit(n,a)
#define ext2_clear_bit_atomic(l,n,a) test_and_clear_bit(n,a)
#include <asm-generic/bitops/minix.h>
#include <asm-generic/bitops/sched.h>
#endif /* __KERNEL__ */
#endif /* _CRIS_BITOPS_H */