/* $NetBSD: mutex.h,v 1.6.68.1 2020/05/13 18:01:49 martin 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 _KERNEL 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_ */