atomic-x86_64.h revision cad56b6ad3ba24d76e073c024aae78d2282058f3 
1/*
2 * Copyright (C) 2014 The Android Open Source Project
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *  * Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 *  * Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in
12 *    the documentation and/or other materials provided with the
13 *    distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
18 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
19 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
22 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
25 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29#ifndef ANDROID_CUTILS_ATOMIC_X86_64_H
30#define ANDROID_CUTILS_ATOMIC_X86_64_H
31
32#include <stdint.h>
33
34#ifndef ANDROID_ATOMIC_INLINE
35#define ANDROID_ATOMIC_INLINE inline __attribute__((always_inline))
36#endif
37
38extern ANDROID_ATOMIC_INLINE
39void android_compiler_barrier(void)
40{
41    __asm__ __volatile__ ("" : : : "memory");
42}
43
44extern ANDROID_ATOMIC_INLINE
45void android_memory_barrier(void)
46{
47    __asm__ __volatile__ ("mfence" : : : "memory");
48}
49
50extern ANDROID_ATOMIC_INLINE
51int32_t android_atomic_acquire_load(volatile const int32_t *ptr)
52{
53    int32_t value = *ptr;
54    android_compiler_barrier();
55    return value;
56}
57
58extern ANDROID_ATOMIC_INLINE
59int32_t android_atomic_release_load(volatile const int32_t *ptr)
60{
61    android_memory_barrier();
62    return *ptr;
63}
64
65extern ANDROID_ATOMIC_INLINE
66void android_atomic_acquire_store(int32_t value, volatile int32_t *ptr)
67{
68    *ptr = value;
69    android_memory_barrier();
70}
71
72extern ANDROID_ATOMIC_INLINE
73void android_atomic_release_store(int32_t value, volatile int32_t *ptr)
74{
75    android_compiler_barrier();
76    *ptr = value;
77}
78
79extern ANDROID_ATOMIC_INLINE
80int android_atomic_cas(int32_t old_value, int32_t new_value,
81                       volatile int32_t *ptr)
82{
83    int32_t prev;
84    __asm__ __volatile__ ("lock; cmpxchgl %1, %2"
85                          : "=a" (prev)
86                          : "q" (new_value), "m" (*ptr), "0" (old_value)
87                          : "memory");
88    return prev != old_value;
89}
90
91extern ANDROID_ATOMIC_INLINE
92int android_atomic_acquire_cas(int32_t old_value, int32_t new_value,
93                               volatile int32_t *ptr)
94{
95    /* Loads are not reordered with other loads. */
96    return android_atomic_cas(old_value, new_value, ptr);
97}
98
99extern ANDROID_ATOMIC_INLINE
100int android_atomic_release_cas(int32_t old_value, int32_t new_value,
101                               volatile int32_t *ptr)
102{
103    /* Stores are not reordered with other stores. */
104    return android_atomic_cas(old_value, new_value, ptr);
105}
106
107extern ANDROID_ATOMIC_INLINE
108int32_t android_atomic_add(int32_t increment, volatile int32_t *ptr)
109{
110    __asm__ __volatile__ ("lock; xaddl %0, %1"
111                          : "+r" (increment), "+m" (*ptr)
112                          : : "memory");
113    /* increment now holds the old value of *ptr */
114    return increment;
115}
116
117extern ANDROID_ATOMIC_INLINE
118int32_t android_atomic_inc(volatile int32_t *addr)
119{
120    return android_atomic_add(1, addr);
121}
122
123extern ANDROID_ATOMIC_INLINE
124int32_t android_atomic_dec(volatile int32_t *addr)
125{
126    return android_atomic_add(-1, addr);
127}
128
129extern ANDROID_ATOMIC_INLINE
130int32_t android_atomic_and(int32_t value, volatile int32_t *ptr)
131{
132    int32_t prev, status;
133    do {
134        prev = *ptr;
135        status = android_atomic_cas(prev, prev & value, ptr);
136    } while (__builtin_expect(status != 0, 0));
137    return prev;
138}
139
140extern ANDROID_ATOMIC_INLINE
141int32_t android_atomic_or(int32_t value, volatile int32_t *ptr)
142{
143    int32_t prev, status;
144    do {
145        prev = *ptr;
146        status = android_atomic_cas(prev, prev | value, ptr);
147    } while (__builtin_expect(status != 0, 0));
148    return prev;
149}
150
151#endif /* ANDROID_CUTILS_ATOMIC_X86_64_H */
152