1 /* $NetBSD: mutex.h,v 1.4 2007/12/09 15:32:27 ad Exp $ */ 2 3 /*- 4 * Copyright (c) 2002, 2006 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 and Andrew Doran. 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 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the NetBSD 21 * Foundation, Inc. and its contributors. 22 * 4. Neither the name of The NetBSD Foundation nor the names of its 23 * contributors may be used to endorse or promote products derived 24 * from this software without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 29 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 36 * POSSIBILITY OF SUCH DAMAGE. 37 */ 38 39 #ifndef _X86_MUTEX_H_ 40 #define _X86_MUTEX_H_ 41 42 struct kmutex { 43 union { 44 volatile uintptr_t mtxa_owner; 45 #ifdef __MUTEX_PRIVATE 46 struct { 47 volatile uint8_t mtxs_dummy; 48 ipl_cookie_t mtxs_ipl; 49 __cpu_simple_lock_t mtxs_lock; 50 volatile uint8_t mtxs_unused; 51 } s; 52 #endif 53 } u; 54 }; 55 56 #ifdef __MUTEX_PRIVATE 57 58 #define mtx_owner u.mtxa_owner 59 #define mtx_ipl u.s.mtxs_ipl 60 #define mtx_lock u.s.mtxs_lock 61 62 #define __HAVE_MUTEX_STUBS 1 63 #define __HAVE_SPIN_MUTEX_STUBS 1 64 #define __HAVE_SIMPLE_MUTEXES 1 65 66 /* 67 * MUTEX_RECEIVE: no memory barrier required, as 'ret' implies a load fence. 68 */ 69 #define MUTEX_RECEIVE(mtx) /* nothing */ 70 71 /* 72 * MUTEX_GIVE: no memory barrier required, as _lock_cas() will take care of it. 73 */ 74 #define MUTEX_GIVE(mtx) /* nothing */ 75 76 #define MUTEX_CAS(p, o, n) \ 77 (_atomic_cas_ulong((volatile unsigned long *)(p), (o), (n)) == (o)) 78 79 unsigned long _atomic_cas_ulong(volatile unsigned long *, 80 unsigned long, unsigned long); 81 82 #endif /* __MUTEX_PRIVATE */ 83 84 #endif /* _X86_MUTEX_H_ */ 85