Linux kernel mirror (for testing)
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1/*
2 * Copyright 2010 Tilera Corporation. All Rights Reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation, version 2.
7 *
8 * This program is distributed in the hope that it will be useful, but
9 * WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
11 * NON INFRINGEMENT. See the GNU General Public License for
12 * more details.
13 *
14 * Atomic primitives.
15 */
16
17#ifndef _ASM_TILE_ATOMIC_H
18#define _ASM_TILE_ATOMIC_H
19
20#include <asm/cmpxchg.h>
21
22#ifndef __ASSEMBLY__
23
24#include <linux/compiler.h>
25#include <linux/types.h>
26
27#define ATOMIC_INIT(i) { (i) }
28
29/**
30 * atomic_read - read atomic variable
31 * @v: pointer of type atomic_t
32 *
33 * Atomically reads the value of @v.
34 */
35static inline int atomic_read(const atomic_t *v)
36{
37 return ACCESS_ONCE(v->counter);
38}
39
40/**
41 * atomic_sub_return - subtract integer and return
42 * @v: pointer of type atomic_t
43 * @i: integer value to subtract
44 *
45 * Atomically subtracts @i from @v and returns @v - @i
46 */
47#define atomic_sub_return(i, v) atomic_add_return((int)(-(i)), (v))
48
49/**
50 * atomic_sub - subtract integer from atomic variable
51 * @i: integer value to subtract
52 * @v: pointer of type atomic_t
53 *
54 * Atomically subtracts @i from @v.
55 */
56#define atomic_sub(i, v) atomic_add((int)(-(i)), (v))
57
58/**
59 * atomic_sub_and_test - subtract value from variable and test result
60 * @i: integer value to subtract
61 * @v: pointer of type atomic_t
62 *
63 * Atomically subtracts @i from @v and returns true if the result is
64 * zero, or false for all other cases.
65 */
66#define atomic_sub_and_test(i, v) (atomic_sub_return((i), (v)) == 0)
67
68/**
69 * atomic_inc_return - increment memory and return
70 * @v: pointer of type atomic_t
71 *
72 * Atomically increments @v by 1 and returns the new value.
73 */
74#define atomic_inc_return(v) atomic_add_return(1, (v))
75
76/**
77 * atomic_dec_return - decrement memory and return
78 * @v: pointer of type atomic_t
79 *
80 * Atomically decrements @v by 1 and returns the new value.
81 */
82#define atomic_dec_return(v) atomic_sub_return(1, (v))
83
84/**
85 * atomic_inc - increment atomic variable
86 * @v: pointer of type atomic_t
87 *
88 * Atomically increments @v by 1.
89 */
90#define atomic_inc(v) atomic_add(1, (v))
91
92/**
93 * atomic_dec - decrement atomic variable
94 * @v: pointer of type atomic_t
95 *
96 * Atomically decrements @v by 1.
97 */
98#define atomic_dec(v) atomic_sub(1, (v))
99
100/**
101 * atomic_dec_and_test - decrement and test
102 * @v: pointer of type atomic_t
103 *
104 * Atomically decrements @v by 1 and returns true if the result is 0.
105 */
106#define atomic_dec_and_test(v) (atomic_dec_return(v) == 0)
107
108/**
109 * atomic_inc_and_test - increment and test
110 * @v: pointer of type atomic_t
111 *
112 * Atomically increments @v by 1 and returns true if the result is 0.
113 */
114#define atomic_inc_and_test(v) (atomic_inc_return(v) == 0)
115
116/**
117 * atomic_add_negative - add and test if negative
118 * @v: pointer of type atomic_t
119 * @i: integer value to add
120 *
121 * Atomically adds @i to @v and returns true if the result is
122 * negative, or false when result is greater than or equal to zero.
123 */
124#define atomic_add_negative(i, v) (atomic_add_return((i), (v)) < 0)
125
126#endif /* __ASSEMBLY__ */
127
128#ifndef __tilegx__
129#include <asm/atomic_32.h>
130#else
131#include <asm/atomic_64.h>
132#endif
133
134#endif /* _ASM_TILE_ATOMIC_H */