xref: /netbsd-src/sys/arch/sh3/include/lock.h (revision a0a7275eea1e9862a6a1f2b8f6155a7cdf5228dc)
1 /*	$NetBSD: lock.h,v 1.19 2022/02/13 13:41:53 riastradh Exp $	*/
2 
3 /*-
4  * Copyright (c) 2002 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Gregory McGarry.
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 _SH3_LOCK_H_
37 #define	_SH3_LOCK_H_
38 
39 static __inline void __cpu_simple_lock_init(__cpu_simple_lock_t *)
40 	__attribute__((__unused__));
41 static __inline void __cpu_simple_lock(__cpu_simple_lock_t *)
42 	__attribute__((__unused__));
43 static __inline int __cpu_simple_lock_try(__cpu_simple_lock_t *)
44 	__attribute__((__unused__));
45 static __inline void __cpu_simple_unlock(__cpu_simple_lock_t *)
46 	__attribute__((__unused__));
47 
48 static __inline int
__SIMPLELOCK_LOCKED_P(const __cpu_simple_lock_t * __ptr)49 __SIMPLELOCK_LOCKED_P(const __cpu_simple_lock_t *__ptr)
50 {
51 	return *__ptr == __SIMPLELOCK_LOCKED;
52 }
53 
54 static __inline int
__SIMPLELOCK_UNLOCKED_P(const __cpu_simple_lock_t * __ptr)55 __SIMPLELOCK_UNLOCKED_P(const __cpu_simple_lock_t *__ptr)
56 {
57 	return *__ptr == __SIMPLELOCK_UNLOCKED;
58 }
59 
60 static __inline void
__cpu_simple_lock_clear(__cpu_simple_lock_t * __ptr)61 __cpu_simple_lock_clear(__cpu_simple_lock_t *__ptr)
62 {
63 	*__ptr = __SIMPLELOCK_UNLOCKED;
64 }
65 
66 static __inline void
__cpu_simple_lock_set(__cpu_simple_lock_t * __ptr)67 __cpu_simple_lock_set(__cpu_simple_lock_t *__ptr)
68 {
69 	*__ptr = __SIMPLELOCK_LOCKED;
70 }
71 
72 static __inline void
__cpu_simple_lock_init(__cpu_simple_lock_t * alp)73 __cpu_simple_lock_init(__cpu_simple_lock_t *alp)
74 {
75 
76 	*alp = __SIMPLELOCK_UNLOCKED;
77 }
78 
79 static __inline void
__cpu_simple_lock(__cpu_simple_lock_t * alp)80 __cpu_simple_lock(__cpu_simple_lock_t *alp)
81 {
82 
83 	 __asm volatile(
84 		"1:	tas.b	@%0	\n"
85 		"	bf	1b	\n"
86 		: /* no outputs */
87 		: "r" (alp)
88 		: "cc", "memory");
89 }
90 
91 static __inline int
__cpu_simple_lock_try(__cpu_simple_lock_t * alp)92 __cpu_simple_lock_try(__cpu_simple_lock_t *alp)
93 {
94 	int __rv;
95 
96 	__asm volatile(
97 		"	tas.b	@%1	\n"
98 		"	movt	%0	\n"
99 		: "=r" (__rv)
100 		: "r" (alp)
101 		: "cc", "memory");
102 
103 	return (__rv);
104 }
105 
106 static __inline void
__cpu_simple_unlock(__cpu_simple_lock_t * alp)107 __cpu_simple_unlock(__cpu_simple_lock_t *alp)
108 {
109 
110 	__insn_barrier();
111 	*alp = __SIMPLELOCK_UNLOCKED;
112 }
113 
114 #endif /* !_SH3_LOCK_H_ */
115