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
38 extern ANDROID_ATOMIC_INLINE
android_compiler_barrier(void)39 void android_compiler_barrier(void)
40 {
41 __asm__ __volatile__ ("" : : : "memory");
42 }
43
44 extern ANDROID_ATOMIC_INLINE
android_memory_barrier(void)45 void android_memory_barrier(void)
46 {
47 __asm__ __volatile__ ("mfence" : : : "memory");
48 }
49
50 extern ANDROID_ATOMIC_INLINE
android_atomic_acquire_load(volatile const int32_t * ptr)51 int32_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
58 extern ANDROID_ATOMIC_INLINE
android_atomic_release_load(volatile const int32_t * ptr)59 int32_t android_atomic_release_load(volatile const int32_t *ptr)
60 {
61 android_memory_barrier();
62 return *ptr;
63 }
64
65 extern ANDROID_ATOMIC_INLINE
android_atomic_acquire_store(int32_t value,volatile int32_t * ptr)66 void android_atomic_acquire_store(int32_t value, volatile int32_t *ptr)
67 {
68 *ptr = value;
69 android_memory_barrier();
70 }
71
72 extern ANDROID_ATOMIC_INLINE
android_atomic_release_store(int32_t value,volatile int32_t * ptr)73 void android_atomic_release_store(int32_t value, volatile int32_t *ptr)
74 {
75 android_compiler_barrier();
76 *ptr = value;
77 }
78
79 extern ANDROID_ATOMIC_INLINE
android_atomic_cas(int32_t old_value,int32_t new_value,volatile int32_t * ptr)80 int 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
91 extern ANDROID_ATOMIC_INLINE
android_atomic_acquire_cas(int32_t old_value,int32_t new_value,volatile int32_t * ptr)92 int 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
99 extern ANDROID_ATOMIC_INLINE
android_atomic_release_cas(int32_t old_value,int32_t new_value,volatile int32_t * ptr)100 int 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
107 extern ANDROID_ATOMIC_INLINE
android_atomic_add(int32_t increment,volatile int32_t * ptr)108 int32_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
117 extern ANDROID_ATOMIC_INLINE
android_atomic_inc(volatile int32_t * addr)118 int32_t android_atomic_inc(volatile int32_t *addr)
119 {
120 return android_atomic_add(1, addr);
121 }
122
123 extern ANDROID_ATOMIC_INLINE
android_atomic_dec(volatile int32_t * addr)124 int32_t android_atomic_dec(volatile int32_t *addr)
125 {
126 return android_atomic_add(-1, addr);
127 }
128
129 extern ANDROID_ATOMIC_INLINE
android_atomic_and(int32_t value,volatile int32_t * ptr)130 int32_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
140 extern ANDROID_ATOMIC_INLINE
android_atomic_or(int32_t value,volatile int32_t * ptr)141 int32_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