aboutsummaryrefslogtreecommitdiff
path: root/arch/tile/include/asm/bitops_32.h
blob: ddc4c1efde43e4524b3942a43d1fa94c2a247417 (plain)
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
/*
 * Copyright 2010 Tilera Corporation. All Rights Reserved.
 *
 *   This program is free software; you can redistribute it and/or
 *   modify it under the terms of the GNU General Public License
 *   as published by the Free Software Foundation, version 2.
 *
 *   This program is distributed in the hope that it will be useful, but
 *   WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
 *   NON INFRINGEMENT.  See the GNU General Public License for
 *   more details.
 */

#ifndef _ASM_TILE_BITOPS_32_H
#define _ASM_TILE_BITOPS_32_H

#include <linux/compiler.h>
#include <linux/atomic.h>

/* Tile-specific routines to support <asm/bitops.h>. */
unsigned long _atomic_or(volatile unsigned long *p, unsigned long mask);
unsigned long _atomic_andn(volatile unsigned long *p, unsigned long mask);
unsigned long _atomic_xor(volatile unsigned long *p, unsigned long mask);

/**
 * 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.
 */
static inline void set_bit(unsigned nr, volatile unsigned long *addr)
{
	_atomic_or(addr + BIT_WORD(nr), BIT_MASK(nr));
}

/**
 * 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.
 * See __clear_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.
 *
 * clear_bit() may 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() to ensure changes are visible on other cpus.
 */
static inline void clear_bit(unsigned nr, volatile unsigned long *addr)
{
	_atomic_andn(addr + BIT_WORD(nr), BIT_MASK(nr));
}

/**
 * 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.
 * See __change_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.
 */
static inline void change_bit(unsigned nr, volatile unsigned long *addr)
{
	_atomic_xor(addr + BIT_WORD(nr), BIT_MASK(nr));
}

/**
 * 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(unsigned nr, volatile unsigned long *addr)
{
	unsigned long mask = BIT_MASK(nr);
	addr += BIT_WORD(nr);
	smp_mb();  /* barrier for proper semantics */
	return (_atomic_or(addr, mask) & mask) != 0;
}

/**
 * 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(unsigned nr, volatile unsigned long *addr)
{
	unsigned long mask = BIT_MASK(nr);
	addr += BIT_WORD(nr);
	smp_mb();  /* barrier for proper semantics */
	return (_atomic_andn(addr, mask) & mask) != 0;
}

/**
 * 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(unsigned nr,
				      volatile unsigned long *addr)
{
	unsigned long mask = BIT_MASK(nr);
	addr += BIT_WORD(nr);
	smp_mb();  /* barrier for proper semantics */
	return (_atomic_xor(addr, mask) & mask) != 0;
}

/* See discussion at smp_mb__before_atomic_dec() in <asm/atomic_32.h>. */
#define smp_mb__before_clear_bit()	smp_mb()
#define smp_mb__after_clear_bit()	do {} while (0)

#include <asm-generic/bitops/ext2-atomic.h>

#endif /* _ASM_TILE_BITOPS_32_H */