1/* $NetBSD: lock.h,v 1.17 2022/02/13 13:41:44 riastradh Exp $ */
2
3/*-
4 * Copyright (c) 2000 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Jason R. Thorpe.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32/*
33 * Machine-dependent spin lock operations.
34 */
35
36#ifndef _M68K_LOCK_H_
37#define _M68K_LOCK_H_
38
39static __inline int
40__SIMPLELOCK_LOCKED_P(const __cpu_simple_lock_t *__ptr)
41{
42 return *__ptr == __SIMPLELOCK_LOCKED;
43}
44
45static __inline int
46__SIMPLELOCK_UNLOCKED_P(const __cpu_simple_lock_t *__ptr)
47{
48 return *__ptr == __SIMPLELOCK_UNLOCKED;
49}
50
51static __inline void
52__cpu_simple_lock_init(__cpu_simple_lock_t *alp)
53{
54
55 *alp = __SIMPLELOCK_UNLOCKED;
56}
57
58
59static __inline void
60__cpu_simple_lock_clear(__cpu_simple_lock_t *__ptr)
61{
62 *__ptr = __SIMPLELOCK_UNLOCKED;
63}
64
65static __inline void
66__cpu_simple_lock_set(__cpu_simple_lock_t *__ptr)
67{
68 *__ptr = __SIMPLELOCK_LOCKED;
69}
70
71static __inline void
72__cpu_simple_lock(__cpu_simple_lock_t *alp)
73{
74
75 __asm volatile(
76 "1: tas %0 \n"
77 " jne 1b \n"
78 : "=m" (*alp)
79 : /* no inputs */
80 : "cc", "memory");
81}
82
83static __inline int
84__cpu_simple_lock_try(__cpu_simple_lock_t *alp)
85{
86 int __rv;
87
88 __asm volatile(
89 " moveq #1, %1 \n"
90 " tas %0 \n"
91 " jeq 1f \n"
92 " moveq #0, %1 \n"
93 "1: \n"
94 : "=m" (*alp), "=d" (__rv)
95 : /* no inputs */
96 : "cc", "memory");
97
98 return (__rv);
99}
100
101static __inline void
102__cpu_simple_unlock(__cpu_simple_lock_t *alp)
103{
104
105 __insn_barrier();
106 *alp = __SIMPLELOCK_UNLOCKED;
107}
108
109#endif /* _M68K_LOCK_H_ */