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_AARCH64_H
30#define ANDROID_CUTILS_ATOMIC_AARCH64_H
31
32#include <stdint.h>
33
34#ifndef ANDROID_ATOMIC_INLINE
35#define ANDROID_ATOMIC_INLINE inline __attribute__((always_inline))
36#endif
37
38/*
39   TODOAArch64: Revisit the below functions and check for potential
40   optimizations using assembly code or otherwise.
41*/
42
43extern ANDROID_ATOMIC_INLINE
44void android_compiler_barrier(void)
45{
46    __asm__ __volatile__ ("" : : : "memory");
47}
48
49extern ANDROID_ATOMIC_INLINE
50void android_memory_barrier(void)
51{
52    __asm__ __volatile__ ("dmb ish" : : : "memory");
53}
54
55extern ANDROID_ATOMIC_INLINE
56int32_t android_atomic_acquire_load(volatile const int32_t *ptr)
57{
58    int32_t value = *ptr;
59    android_memory_barrier();
60    return value;
61}
62
63extern ANDROID_ATOMIC_INLINE
64int32_t android_atomic_release_load(volatile const int32_t *ptr)
65{
66    android_memory_barrier();
67    return *ptr;
68}
69
70extern ANDROID_ATOMIC_INLINE
71void android_atomic_acquire_store(int32_t value, volatile int32_t *ptr)
72{
73    *ptr = value;
74    android_memory_barrier();
75}
76
77extern ANDROID_ATOMIC_INLINE
78void android_atomic_release_store(int32_t value, volatile int32_t *ptr)
79{
80    android_memory_barrier();
81    *ptr = value;
82}
83
84extern ANDROID_ATOMIC_INLINE
85int android_atomic_cas(int32_t old_value, int32_t new_value,
86                       volatile int32_t *ptr)
87{
88    return __sync_val_compare_and_swap(ptr, old_value, new_value) != 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    int status = android_atomic_cas(old_value, new_value, ptr);
96    android_memory_barrier();
97    return status;
98}
99
100extern ANDROID_ATOMIC_INLINE
101int android_atomic_release_cas(int32_t old_value, int32_t new_value,
102                               volatile int32_t *ptr)
103{
104    android_memory_barrier();
105    return android_atomic_cas(old_value, new_value, ptr);
106}
107
108extern ANDROID_ATOMIC_INLINE
109int32_t android_atomic_add(int32_t increment, volatile int32_t *ptr)
110{
111    int32_t prev, status;
112    android_memory_barrier();
113    do {
114        prev = *ptr;
115        status = android_atomic_cas(prev, prev + increment, ptr);
116    } while (__builtin_expect(status != 0, 0));
117    return prev;
118}
119
120extern ANDROID_ATOMIC_INLINE
121int32_t android_atomic_inc(volatile int32_t *addr)
122{
123    return android_atomic_add(1, addr);
124}
125
126extern ANDROID_ATOMIC_INLINE
127int32_t android_atomic_dec(volatile int32_t *addr)
128{
129    return android_atomic_add(-1, addr);
130}
131
132extern ANDROID_ATOMIC_INLINE
133int32_t android_atomic_and(int32_t value, volatile int32_t *ptr)
134{
135    int32_t prev, status;
136    android_memory_barrier();
137    do {
138        prev = *ptr;
139        status = android_atomic_cas(prev, prev & value, ptr);
140    } while (__builtin_expect(status != 0, 0));
141    return prev;
142}
143
144extern ANDROID_ATOMIC_INLINE
145int32_t android_atomic_or(int32_t value, volatile int32_t *ptr)
146{
147    int32_t prev, status;
148    android_memory_barrier();
149    do {
150        prev = *ptr;
151        status = android_atomic_cas(prev, prev | value, ptr);
152    } while (__builtin_expect(status != 0, 0));
153    return prev;
154}
155
156#endif /* ANDROID_CUTILS_ATOMIC_AARCH64_H */
157