1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
|
/*
* Copyright (c) 2017 Agustina Arzille.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef _KERN_ATOMIC_H
#define _KERN_ATOMIC_H
#include <machine/atomic.h>
/*
* Supported memory orders.
*/
#define ATOMIC_RELAXED __ATOMIC_RELAXED
#define ATOMIC_ACQUIRE __ATOMIC_ACQUIRE
#define ATOMIC_RELEASE __ATOMIC_RELEASE
#define ATOMIC_ACQ_REL __ATOMIC_ACQ_REL
#define ATOMIC_SEQ_CST __ATOMIC_SEQ_CST
/*
* Type-generic atomic operations.
*/
#define atomic_fetch_add(ptr, val, mo) __atomic_fetch_add((ptr), (val), mo)
#define atomic_fetch_sub(ptr, val, mo) __atomic_fetch_sub((ptr), (val), mo)
#define atomic_fetch_and(ptr, val, mo) __atomic_fetch_and((ptr), (val), mo)
#define atomic_fetch_or(ptr, val, mo) __atomic_fetch_or((ptr), (val), mo)
#define atomic_fetch_xor(ptr, val, mo) __atomic_fetch_xor((ptr), (val), mo)
#define atomic_add(ptr, val, mo) ((void)__atomic_add_fetch((ptr), (val), mo))
#define atomic_sub(ptr, val, mo) ((void)__atomic_sub_fetch((ptr), (val), mo))
#define atomic_and(ptr, val, mo) ((void)__atomic_and_fetch((ptr), (val), mo))
#define atomic_or(ptr, val, mo) ((void)__atomic_or_fetch((ptr), (val), mo))
#define atomic_xor(ptr, val, mo) ((void)__atomic_xor_fetch((ptr), (val), mo))
#define atomic_swap(ptr, val, mo) __atomic_exchange_n((ptr), (val), mo)
/*
* For compare-and-swap, we deviate a little from the standard, and only
* return the value before the comparison, leaving it up to the user to
* determine whether the swap was actually performed or not.
* Also, note that the memory order in case of failure is relaxed. This is
* because atomic CAS is typically used in a loop. However, if a different
* code path is taken on failure (rather than retrying), then the user
* should be aware that a memory fence might be necessary.
*/
#define atomic_cas(ptr, exp, nval, mo) \
MACRO_BEGIN \
typeof(*(ptr)) ___exp, ___nval; \
\
___exp = (exp); \
___nval = (nval); \
__atomic_compare_exchange_n((ptr), &___exp, ___nval, 0, mo, \
ATOMIC_RELAXED); \
___exp; \
MACRO_END
/*
* Some architectures may need specific definitions for loads and stores,
* in order to prevent the compiler from emitting unsupported instructions.
* As such, we only define these if the arch header didn't already.
*/
#ifndef ATOMIC_LOAD_DEFINED
#define atomic_load(ptr, mo) __atomic_load_n((ptr), mo)
#endif /* ATOMIC_LOAD_DEFINED */
#ifndef ATOMIC_STORE_DEFINED
#define atomic_store(ptr, val, mo) __atomic_store_n((ptr), (val), mo)
#endif /* ATOMIC_STORE_DEFINED */
/*
* Common shortcuts.
*/
#define atomic_cas_acquire(ptr, exp, val) \
atomic_cas(ptr, exp, val, ATOMIC_ACQUIRE)
#define atomic_cas_release(ptr, exp, val) \
atomic_cas(ptr, exp, val, ATOMIC_RELEASE)
#define atomic_cas_seq_cst(ptr, exp, val) \
atomic_cas(ptr, exp, val, ATOMIC_SEQ_CST)
#define atomic_swap_acquire(ptr, val) atomic_swap(ptr, val, ATOMIC_ACQUIRE)
#define atomic_swap_release(ptr, val) atomic_swap(ptr, val, ATOMIC_RELEASE)
#define atomic_swap_seq_cst(ptr, val) atomic_swap(ptr, val, ATOMIC_SEQ_CST)
#define atomic_fetch_add_acq_rel(ptr, val) \
atomic_fetch_add(ptr, val, ATOMIC_ACQ_REL)
#define atomic_fetch_sub_acq_rel(ptr, val) \
atomic_fetch_sub(ptr, val, ATOMIC_ACQ_REL)
#define atomic_or_acq_rel(ptr, val) atomic_or(ptr, val, ATOMIC_ACQ_REL)
#define atomic_and_acq_rel(ptr, val) atomic_and(ptr, val, ATOMIC_ACQ_REL)
#endif /* _KERN_ATOMIC_H */
|
