Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
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#ifndef __ASSEMBLY__
21
22#include <linux/compiler.h>
23#include <asm/system.h>
24
25#define ATOMIC_INIT(i) { (i) }
26
27/**
28 * atomic_read - read atomic variable
29 * @v: pointer of type atomic_t
30 *
31 * Atomically reads the value of @v.
32 */
33static inline int atomic_read(const atomic_t *v)
34{
35 return ACCESS_ONCE(v->counter);
36}
37
38/**
39 * atomic_sub_return - subtract integer and return
40 * @v: pointer of type atomic_t
41 * @i: integer value to subtract
42 *
43 * Atomically subtracts @i from @v and returns @v - @i
44 */
45#define atomic_sub_return(i, v) atomic_add_return((int)(-(i)), (v))
46
47/**
48 * atomic_sub - subtract integer from atomic variable
49 * @i: integer value to subtract
50 * @v: pointer of type atomic_t
51 *
52 * Atomically subtracts @i from @v.
53 */
54#define atomic_sub(i, v) atomic_add((int)(-(i)), (v))
55
56/**
57 * atomic_sub_and_test - subtract value from variable and test result
58 * @i: integer value to subtract
59 * @v: pointer of type atomic_t
60 *
61 * Atomically subtracts @i from @v and returns true if the result is
62 * zero, or false for all other cases.
63 */
64#define atomic_sub_and_test(i, v) (atomic_sub_return((i), (v)) == 0)
65
66/**
67 * atomic_inc_return - increment memory and return
68 * @v: pointer of type atomic_t
69 *
70 * Atomically increments @v by 1 and returns the new value.
71 */
72#define atomic_inc_return(v) atomic_add_return(1, (v))
73
74/**
75 * atomic_dec_return - decrement memory and return
76 * @v: pointer of type atomic_t
77 *
78 * Atomically decrements @v by 1 and returns the new value.
79 */
80#define atomic_dec_return(v) atomic_sub_return(1, (v))
81
82/**
83 * atomic_inc - increment atomic variable
84 * @v: pointer of type atomic_t
85 *
86 * Atomically increments @v by 1.
87 */
88#define atomic_inc(v) atomic_add(1, (v))
89
90/**
91 * atomic_dec - decrement atomic variable
92 * @v: pointer of type atomic_t
93 *
94 * Atomically decrements @v by 1.
95 */
96#define atomic_dec(v) atomic_sub(1, (v))
97
98/**
99 * atomic_dec_and_test - decrement and test
100 * @v: pointer of type atomic_t
101 *
102 * Atomically decrements @v by 1 and returns true if the result is 0.
103 */
104#define atomic_dec_and_test(v) (atomic_dec_return(v) == 0)
105
106/**
107 * atomic_inc_and_test - increment and test
108 * @v: pointer of type atomic_t
109 *
110 * Atomically increments @v by 1 and returns true if the result is 0.
111 */
112#define atomic_inc_and_test(v) (atomic_inc_return(v) == 0)
113
114/**
115 * atomic_add_negative - add and test if negative
116 * @v: pointer of type atomic_t
117 * @i: integer value to add
118 *
119 * Atomically adds @i to @v and returns true if the result is
120 * negative, or false when result is greater than or equal to zero.
121 */
122#define atomic_add_negative(i, v) (atomic_add_return((i), (v)) < 0)
123
124/**
125 * atomic_inc_not_zero - increment unless the number is zero
126 * @v: pointer of type atomic_t
127 *
128 * Atomically increments @v by 1, so long as @v is non-zero.
129 * Returns non-zero if @v was non-zero, and zero otherwise.
130 */
131#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
132
133/* Nonexistent functions intended to cause link errors. */
134extern unsigned long __xchg_called_with_bad_pointer(void);
135extern unsigned long __cmpxchg_called_with_bad_pointer(void);
136
137#define xchg(ptr, x) \
138 ({ \
139 typeof(*(ptr)) __x; \
140 switch (sizeof(*(ptr))) { \
141 case 4: \
142 __x = (typeof(__x))(typeof(__x-__x))atomic_xchg( \
143 (atomic_t *)(ptr), \
144 (u32)(typeof((x)-(x)))(x)); \
145 break; \
146 case 8: \
147 __x = (typeof(__x))(typeof(__x-__x))atomic64_xchg( \
148 (atomic64_t *)(ptr), \
149 (u64)(typeof((x)-(x)))(x)); \
150 break; \
151 default: \
152 __xchg_called_with_bad_pointer(); \
153 } \
154 __x; \
155 })
156
157#define cmpxchg(ptr, o, n) \
158 ({ \
159 typeof(*(ptr)) __x; \
160 switch (sizeof(*(ptr))) { \
161 case 4: \
162 __x = (typeof(__x))(typeof(__x-__x))atomic_cmpxchg( \
163 (atomic_t *)(ptr), \
164 (u32)(typeof((o)-(o)))(o), \
165 (u32)(typeof((n)-(n)))(n)); \
166 break; \
167 case 8: \
168 __x = (typeof(__x))(typeof(__x-__x))atomic64_cmpxchg( \
169 (atomic64_t *)(ptr), \
170 (u64)(typeof((o)-(o)))(o), \
171 (u64)(typeof((n)-(n)))(n)); \
172 break; \
173 default: \
174 __cmpxchg_called_with_bad_pointer(); \
175 } \
176 __x; \
177 })
178
179#define tas(ptr) (xchg((ptr), 1))
180
181#endif /* __ASSEMBLY__ */
182
183#ifndef __tilegx__
184#include <asm/atomic_32.h>
185#else
186#include <asm/atomic_64.h>
187#endif
188
189/* Provide the appropriate atomic_long_t definitions. */
190#ifndef __ASSEMBLY__
191#include <asm-generic/atomic-long.h>
192#endif
193
194#endif /* _ASM_TILE_ATOMIC_H */