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
|
/* Atomic operations. PowerPC32 version.
Copyright (C) 2003-2014 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Paul Mackerras <paulus@au.ibm.com>, 2003.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
/* POWER6 adds a "Mutex Hint" to the Load and Reserve instruction.
This is a hint to the hardware to expect additional updates adjacent
to the lock word or not. If we are acquiring a Mutex, the hint
should be true. Otherwise we releasing a Mutex or doing a simple
atomic operation. In that case we don't expect additional updates
adjacent to the lock word after the Store Conditional and the hint
should be false. */
#if defined _ARCH_PWR6 || defined _ARCH_PWR6X
# define MUTEX_HINT_ACQ ",1"
# define MUTEX_HINT_REL ",0"
#else
# define MUTEX_HINT_ACQ
# define MUTEX_HINT_REL
#endif
/*
* The 32-bit exchange_bool is different on powerpc64 because the subf
* does signed 64-bit arithmetic while the lwarx is 32-bit unsigned
* (a load word and zero (high 32) form). So powerpc64 has a slightly
* different version in sysdeps/powerpc/powerpc64/bits/atomic.h.
*/
#define __arch_compare_and_exchange_bool_32_acq(mem, newval, oldval) \
({ \
unsigned int __tmp; \
__asm __volatile ( \
"1: lwarx %0,0,%1" MUTEX_HINT_ACQ "\n" \
" subf. %0,%2,%0\n" \
" bne 2f\n" \
" stwcx. %3,0,%1\n" \
" bne- 1b\n" \
"2: " __ARCH_ACQ_INSTR \
: "=&r" (__tmp) \
: "b" (mem), "r" (oldval), "r" (newval) \
: "cr0", "memory"); \
__tmp != 0; \
})
#define __arch_compare_and_exchange_bool_32_rel(mem, newval, oldval) \
({ \
unsigned int __tmp; \
__asm __volatile (__ARCH_REL_INSTR "\n" \
"1: lwarx %0,0,%1" MUTEX_HINT_REL "\n" \
" subf. %0,%2,%0\n" \
" bne 2f\n" \
" stwcx. %3,0,%1\n" \
" bne- 1b\n" \
"2: " \
: "=&r" (__tmp) \
: "b" (mem), "r" (oldval), "r" (newval) \
: "cr0", "memory"); \
__tmp != 0; \
})
/* Powerpc32 processors don't implement the 64-bit (doubleword) forms of
load and reserve (ldarx) and store conditional (stdcx.) instructions.
So for powerpc32 we stub out the 64-bit forms. */
#define __arch_compare_and_exchange_bool_64_acq(mem, newval, oldval) \
(abort (), 0)
#define __arch_compare_and_exchange_val_64_acq(mem, newval, oldval) \
(abort (), (__typeof (*mem)) 0)
#define __arch_compare_and_exchange_bool_64_rel(mem, newval, oldval) \
(abort (), 0)
#define __arch_compare_and_exchange_val_64_rel(mem, newval, oldval) \
(abort (), (__typeof (*mem)) 0)
#define __arch_atomic_exchange_64_acq(mem, value) \
({ abort (); (*mem) = (value); })
#define __arch_atomic_exchange_64_rel(mem, value) \
({ abort (); (*mem) = (value); })
#define __arch_atomic_exchange_and_add_64(mem, value) \
({ abort (); (*mem) = (value); })
#define __arch_atomic_increment_val_64(mem) \
({ abort (); (*mem)++; })
#define __arch_atomic_decrement_val_64(mem) \
({ abort (); (*mem)--; })
#define __arch_atomic_decrement_if_positive_64(mem) \
({ abort (); (*mem)--; })
#ifdef _ARCH_PWR4
/*
* Newer powerpc64 processors support the new "light weight" sync (lwsync)
* So if the build is using -mcpu=[power4,power5,power5+,970] we can
* safely use lwsync.
*/
# define atomic_read_barrier() __asm ("lwsync" ::: "memory")
/*
* "light weight" sync can also be used for the release barrier.
*/
# ifndef UP
# define __ARCH_REL_INSTR "lwsync"
# endif
#else
/*
* Older powerpc32 processors don't support the new "light weight"
* sync (lwsync). So the only safe option is to use normal sync
* for all powerpc32 applications.
*/
# define atomic_read_barrier() __asm ("sync" ::: "memory")
#endif
/*
* Include the rest of the atomic ops macros which are common to both
* powerpc32 and powerpc64.
*/
#include_next <bits/atomic.h>
|
