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
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
|
/*
* Based on arch/arm/include/asm/cmpxchg.h
*
* Copyright (C) 2012 ARM Ltd.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* 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 __ASM_CMPXCHG_H
#define __ASM_CMPXCHG_H
#include <linux/bug.h>
#include <asm/barrier.h>
static inline unsigned long __xchg(unsigned long x, volatile void *ptr, int size)
{
unsigned long ret, tmp;
switch (size) {
case 1:
asm volatile("// __xchg1\n"
"1: ldaxrb %w0, %2\n"
" stlxrb %w1, %w3, %2\n"
" cbnz %w1, 1b\n"
: "=&r" (ret), "=&r" (tmp), "+Q" (*(u8 *)ptr)
: "r" (x)
: "cc", "memory");
break;
case 2:
asm volatile("// __xchg2\n"
"1: ldaxrh %w0, %2\n"
" stlxrh %w1, %w3, %2\n"
" cbnz %w1, 1b\n"
: "=&r" (ret), "=&r" (tmp), "+Q" (*(u16 *)ptr)
: "r" (x)
: "cc", "memory");
break;
case 4:
asm volatile("// __xchg4\n"
"1: ldaxr %w0, %2\n"
" stlxr %w1, %w3, %2\n"
" cbnz %w1, 1b\n"
: "=&r" (ret), "=&r" (tmp), "+Q" (*(u32 *)ptr)
: "r" (x)
: "cc", "memory");
break;
case 8:
asm volatile("// __xchg8\n"
"1: ldaxr %0, %2\n"
" stlxr %w1, %3, %2\n"
" cbnz %w1, 1b\n"
: "=&r" (ret), "=&r" (tmp), "+Q" (*(u64 *)ptr)
: "r" (x)
: "cc", "memory");
break;
default:
BUILD_BUG();
}
return ret;
}
#define xchg(ptr,x) \
((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))
static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old,
unsigned long new, int size)
{
unsigned long oldval = 0, res;
switch (size) {
case 1:
do {
asm volatile("// __cmpxchg1\n"
" ldxrb %w1, %2\n"
" mov %w0, #0\n"
" cmp %w1, %w3\n"
" b.ne 1f\n"
" stxrb %w0, %w4, %2\n"
"1:\n"
: "=&r" (res), "=&r" (oldval), "+Q" (*(u8 *)ptr)
: "Ir" (old), "r" (new)
: "cc");
} while (res);
break;
case 2:
do {
asm volatile("// __cmpxchg2\n"
" ldxrh %w1, %2\n"
" mov %w0, #0\n"
" cmp %w1, %w3\n"
" b.ne 1f\n"
" stxrh %w0, %w4, %2\n"
"1:\n"
: "=&r" (res), "=&r" (oldval), "+Q" (*(u16 *)ptr)
: "Ir" (old), "r" (new)
: "cc");
} while (res);
break;
case 4:
do {
asm volatile("// __cmpxchg4\n"
" ldxr %w1, %2\n"
" mov %w0, #0\n"
" cmp %w1, %w3\n"
" b.ne 1f\n"
" stxr %w0, %w4, %2\n"
"1:\n"
: "=&r" (res), "=&r" (oldval), "+Q" (*(u32 *)ptr)
: "Ir" (old), "r" (new)
: "cc");
} while (res);
break;
case 8:
do {
asm volatile("// __cmpxchg8\n"
" ldxr %1, %2\n"
" mov %w0, #0\n"
" cmp %1, %3\n"
" b.ne 1f\n"
" stxr %w0, %4, %2\n"
"1:\n"
: "=&r" (res), "=&r" (oldval), "+Q" (*(u64 *)ptr)
: "Ir" (old), "r" (new)
: "cc");
} while (res);
break;
default:
BUILD_BUG();
}
return oldval;
}
static inline unsigned long __cmpxchg_mb(volatile void *ptr, unsigned long old,
unsigned long new, int size)
{
unsigned long ret;
smp_mb();
ret = __cmpxchg(ptr, old, new, size);
smp_mb();
return ret;
}
#define cmpxchg(ptr,o,n) \
((__typeof__(*(ptr)))__cmpxchg_mb((ptr), \
(unsigned long)(o), \
(unsigned long)(n), \
sizeof(*(ptr))))
#define cmpxchg_local(ptr,o,n) \
((__typeof__(*(ptr)))__cmpxchg((ptr), \
(unsigned long)(o), \
(unsigned long)(n), \
sizeof(*(ptr))))
#define cmpxchg64(ptr,o,n) cmpxchg((ptr),(o),(n))
#define cmpxchg64_local(ptr,o,n) cmpxchg_local((ptr),(o),(n))
#define cmpxchg64_relaxed(ptr,o,n) cmpxchg_local((ptr),(o),(n))
#endif /* __ASM_CMPXCHG_H */
|
