/*      $NetBSD: mutex.h,v 1.6 2023/07/12 12:50:13 riastradh Exp $      */

/*-
 * Copyright (c) 2002, 2006 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Jason R. Thorpe and Andrew Doran.
 *
 * 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.
 */

#ifndef _ARCH_USERMODE_INCLUDE_MUTEX_H_
#define _ARCH_USERMODE_INCLUDE_MUTEX_H_

#include <sys/types.h>

#ifdef __MUTEX_PRIVATE
#include <machine/intr.h>
#endif

struct kmutex {
        union {
                volatile uintptr_t      mtxa_owner;
#ifdef __MUTEX_PRIVATE
                struct {
                        volatile uint8_t        mtxs_dummy;
                        ipl_cookie_t            mtxs_ipl;
                        __cpu_simple_lock_t     mtxs_lock;
                        volatile uint8_t        mtxs_unused;
                } s;
#endif
        } u;
};

#ifdef __MUTEX_PRIVATE

#define mtx_owner                       u.mtxa_owner
#define mtx_ipl                         u.s.mtxs_ipl
#define mtx_lock                        u.s.mtxs_lock

#define __HAVE_SIMPLE_MUTEXES           1

#define MUTEX_CAS(p, o, n)              \
    (_atomic_cas_ulong((volatile unsigned long *)(p), (o), (n)) == (o))

unsigned long   _atomic_cas_ulong(volatile unsigned long *,
    unsigned long, unsigned long);

#endif  /* __MUTEX_PRIVATE */

#endif /* _ARCH_USERMODE_INCLUDE_MUTEX_H_ */