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_ */