LCOM1920-T02G10

/*        $NetBSD: mutex.h,v 1.6 2009/04/24 17:49:51 ad Exp $        */

/*-

 * Copyright (c) 2002, 2006, 2009 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 _X86_MUTEX_H_

#define        _X86_MUTEX_H_

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_MUTEX_STUBS                1

#define __HAVE_SPIN_MUTEX_STUBS                1

#define        __HAVE_SIMPLE_MUTEXES                1

/*

 * MUTEX_RECEIVE: technically, no memory barrier is required

 * as 'ret' implies a load fence.  However we need this to

 * handle a bug with some Opteron revisions.  See patch.c,

 * lock_stubs.S.

 */

#define        MUTEX_RECEIVE(mtx)                membar_consumer()

/*

 * MUTEX_GIVE: no memory barrier required, as _lock_cas() will take care of it.

 */

#define        MUTEX_GIVE(mtx)                        /* nothing */

#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 /* _X86_MUTEX_H_ */