aboutsummaryrefslogtreecommitdiff
path: root/arch/tile/include/asm/atomic.h
blob: b8c49f98a44c3b945c2a0addeb62e30957215881 (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
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
/*
 * 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.
 *
 * Atomic primitives.
 */

#ifndef _ASM_TILE_ATOMIC_H
#define _ASM_TILE_ATOMIC_H

#ifndef __ASSEMBLY__

#include <linux/compiler.h>
#include <asm/system.h>

#define ATOMIC_INIT(i)	{ (i) }

/**
 * atomic_read - read atomic variable
 * @v: pointer of type atomic_t
 *
 * Atomically reads the value of @v.
 */
static inline int atomic_read(const atomic_t *v)
{
       return v->counter;
}

/**
 * atomic_sub_return - subtract integer and return
 * @v: pointer of type atomic_t
 * @i: integer value to subtract
 *
 * Atomically subtracts @i from @v and returns @v - @i
 */
#define atomic_sub_return(i, v)		atomic_add_return((int)(-(i)), (v))

/**
 * atomic_sub - subtract integer from atomic variable
 * @i: integer value to subtract
 * @v: pointer of type atomic_t
 *
 * Atomically subtracts @i from @v.
 */
#define atomic_sub(i, v)		atomic_add((int)(-(i)), (v))

/**
 * atomic_sub_and_test - subtract value from variable and test result
 * @i: integer value to subtract
 * @v: pointer of type atomic_t
 *
 * Atomically subtracts @i from @v and returns true if the result is
 * zero, or false for all other cases.
 */
#define atomic_sub_and_test(i, v)	(atomic_sub_return((i), (v)) == 0)

/**
 * atomic_inc_return - increment memory and return
 * @v: pointer of type atomic_t
 *
 * Atomically increments @v by 1 and returns the new value.
 */
#define atomic_inc_return(v)		atomic_add_return(1, (v))

/**
 * atomic_dec_return - decrement memory and return
 * @v: pointer of type atomic_t
 *
 * Atomically decrements @v by 1 and returns the new value.
 */
#define atomic_dec_return(v)		atomic_sub_return(1, (v))

/**
 * atomic_inc - increment atomic variable
 * @v: pointer of type atomic_t
 *
 * Atomically increments @v by 1.
 */
#define atomic_inc(v)			atomic_add(1, (v))

/**
 * atomic_dec - decrement atomic variable
 * @v: pointer of type atomic_t
 *
 * Atomically decrements @v by 1.
 */
#define atomic_dec(v)			atomic_sub(1, (v))

/**
 * atomic_dec_and_test - decrement and test
 * @v: pointer of type atomic_t
 *
 * Atomically decrements @v by 1 and returns true if the result is 0.
 */
#define atomic_dec_and_test(v)		(atomic_dec_return(v) == 0)

/**
 * atomic_inc_and_test - increment and test
 * @v: pointer of type atomic_t
 *
 * Atomically increments @v by 1 and returns true if the result is 0.
 */
#define atomic_inc_and_test(v)		(atomic_inc_return(v) == 0)

/**
 * atomic_add_negative - add and test if negative
 * @v: pointer of type atomic_t
 * @i: integer value to add
 *
 * Atomically adds @i to @v and returns true if the result is
 * negative, or false when result is greater than or equal to zero.
 */
#define atomic_add_negative(i, v)	(atomic_add_return((i), (v)) < 0)

/**
 * atomic_inc_not_zero - increment unless the number is zero
 * @v: pointer of type atomic_t
 *
 * Atomically increments @v by 1, so long as @v is non-zero.
 * Returns non-zero if @v was non-zero, and zero otherwise.
 */
#define atomic_inc_not_zero(v)		atomic_add_unless((v), 1, 0)


/*
 * We define xchg() and cmpxchg() in the included headers.
 * Note that we do not define __HAVE_ARCH_CMPXCHG, since that would imply
 * that cmpxchg() is an efficient operation, which is not particularly true.
 */

/* Nonexistent functions intended to cause link errors. */
extern unsigned long __xchg_called_with_bad_pointer(void);
extern unsigned long __cmpxchg_called_with_bad_pointer(void);

#define tas(ptr) (xchg((ptr), 1))

#endif /* __ASSEMBLY__ */

#ifndef __tilegx__
#include <asm/atomic_32.h>
#else
#include <asm/atomic_64.h>
#endif

/* Provide the appropriate atomic_long_t definitions. */
#ifndef __ASSEMBLY__
#include <asm-generic/atomic-long.h>
#endif

#endif /* _ASM_TILE_ATOMIC_H */