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
|
/* $NetBSD: lock.h,v 1.5 2003/09/26 22:46:01 nathanw Exp $ */
/*-
* Copyright (c) 2001 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Wayne Knowles.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the NetBSD
* Foundation, Inc. and its contributors.
* 4. Neither the name of The NetBSD Foundation nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
/*
* Machine-dependent spin lock operations for MIPS R4000 Processors.
*
* Note: R3000 doesn't have any atomic update instructions
*/
#ifndef _MIPS_LOCK_H_
#define _MIPS_LOCK_H_
static __inline void
__cpu_simple_lock_init(__cpu_simple_lock_t *lp)
{
__asm __volatile(
"# -- BEGIN __cpu_simple_lock_init\n"
" .set push \n"
" .set mips2 \n"
" sw $0, %0 \n"
" sync \n"
" .set pop \n"
"# -- END __cpu_simple_lock_init\n"
: "=m" (*lp));
}
static __inline void
__cpu_simple_lock(__cpu_simple_lock_t *lp)
{
unsigned long t0;
/*
* Note, if we detect that the lock is held when
* we do the initial load-locked, we spin using
* a non-locked load to save the coherency logic
* some work.
*/
__asm __volatile(
"# -- BEGIN __cpu_simple_lock \n"
" .set push \n"
" .set mips2 \n"
"1: ll %0, %3 \n"
" bnez %0, 2f \n"
" nop # BDslot \n"
" li %0, %2 \n"
" sc %0, %1 \n"
" beqz %0, 1b \n"
" nop # BDslot \n"
" nop \n"
" sync \n"
" j 3f \n"
" nop \n"
" nop \n"
"2: lw %0, %3 \n"
" bnez %0, 2b \n"
" nop # BDslot \n"
" j 1b \n"
" nop \n"
"3: \n"
" .set pop \n"
"# -- END __cpu_simple_lock \n"
: "=r" (t0), "+m" (*lp)
: "i" (__SIMPLELOCK_LOCKED), "1" (*lp));
}
static __inline int
__cpu_simple_lock_try(__cpu_simple_lock_t *lp)
{
unsigned long t0, v0;
__asm __volatile(
"# -- BEGIN __cpu_simple_lock_try\n"
" .set push \n"
" .set mips2 \n"
"1: ll %0, %4 \n"
" bnez %0, 2f \n"
" nop # BDslot \n"
" li %0, %3 \n"
" sc %0, %2 \n"
" beqz %0, 2f \n"
" nop # BDslot \n"
" li %1, 1 \n"
" sync \n"
" j 3f \n"
" nop \n"
" nop \n"
"2: li %1, 0 \n"
"3: \n"
" .set pop \n"
"# -- END __cpu_simple_lock_try \n"
: "=r" (t0), "=r" (v0), "+m" (*lp)
: "i" (__SIMPLELOCK_LOCKED), "2" (*lp));
return (v0 != 0);
}
static __inline void
__cpu_simple_unlock(__cpu_simple_lock_t *lp)
{
__asm __volatile(
"# -- BEGIN __cpu_simple_unlock \n"
" .set push \n"
" .set mips2 \n"
" sync \n"
" sw $0, %0 \n"
" .set pop \n"
"# -- END __cpu_simple_unlock \n"
: "=m" (*lp));
}
#endif /* _MIPS_LOCK_H_ */
|