/*      $NetBSD: lock.h,v 1.17 2022/02/13 13:41:44 riastradh Exp $      */

/*-
* Copyright (c) 2000 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Jason R. Thorpe.
*
* 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.
*
* 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.
*/

#ifndef _M68K_LOCK_H_
#define _M68K_LOCK_H_

static __inline int
__SIMPLELOCK_LOCKED_P(const __cpu_simple_lock_t *__ptr)
{
       return *__ptr == __SIMPLELOCK_LOCKED;
}

static __inline int
__SIMPLELOCK_UNLOCKED_P(const __cpu_simple_lock_t *__ptr)
{
       return *__ptr == __SIMPLELOCK_UNLOCKED;
}

static __inline void
__cpu_simple_lock_init(__cpu_simple_lock_t *alp)
{

       *alp = __SIMPLELOCK_UNLOCKED;
}


static __inline void
__cpu_simple_lock_clear(__cpu_simple_lock_t *__ptr)
{
       *__ptr = __SIMPLELOCK_UNLOCKED;
}

static __inline void
__cpu_simple_lock_set(__cpu_simple_lock_t *__ptr)
{
       *__ptr = __SIMPLELOCK_LOCKED;
}

static __inline void
__cpu_simple_lock(__cpu_simple_lock_t *alp)
{

       __asm volatile(
               "1:     tas     %0      \n"
               "       jne     1b      \n"
               : "=m" (*alp)
               : /* no inputs */
               : "cc", "memory");
}

static __inline int
__cpu_simple_lock_try(__cpu_simple_lock_t *alp)
{
       int __rv;

       __asm volatile(
               "       moveq   #1, %1  \n"
               "       tas     %0      \n"
               "       jeq     1f      \n"
               "       moveq   #0, %1  \n"
               "1:                     \n"
               : "=m" (*alp), "=d" (__rv)
               : /* no inputs */
               : "cc", "memory");

       return (__rv);
}

static __inline void
__cpu_simple_unlock(__cpu_simple_lock_t *alp)
{

       __insn_barrier();
       *alp = __SIMPLELOCK_UNLOCKED;
}

#endif /* _M68K_LOCK_H_ */