1 /* $NetBSD: mutex.h,v 1.20 2023/07/12 12:50:13 riastradh Exp $ */ 2 3 /*- 4 * Copyright (c) 2002, 2007 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 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 #ifndef _VAX_MUTEX_H_ 33 #define _VAX_MUTEX_H_ 34 35 /* 36 * The VAX mutex implementation is troublesome, because VAX lacks a 37 * compare-and-swap operation. 38 * 39 * So we emulate compare-and-swap by raising IPL to lock out interrupts 40 * and (if MP) using BBSSI/BBCCI to lock out the other processors. 41 */ 42 43 #include <sys/types.h> 44 45 #ifndef __MUTEX_PRIVATE 46 47 struct kmutex { 48 uintptr_t mtx_pad1; 49 }; 50 51 #else /* __MUTEX_PRIVATE */ 52 53 #include <machine/intr.h> 54 55 struct kmutex { 56 union { 57 /* Adaptive mutex */ 58 volatile uintptr_t mtxa_owner; /* 0-3 */ 59 60 /* Spin mutex */ 61 struct { 62 volatile uint8_t mtxs_dummy; 63 ipl_cookie_t mtxs_ipl; 64 __cpu_simple_lock_t mtxs_lock; 65 volatile uint8_t mtxs_unused; 66 } s; 67 } u; 68 }; 69 70 #define mtx_owner u.mtxa_owner 71 #define mtx_ipl u.s.mtxs_ipl 72 #define mtx_lock u.s.mtxs_lock 73 74 #define __HAVE_MUTEX_STUBS 1 75 #define __HAVE_SPIN_MUTEX_STUBS 1 76 #define __HAVE_SIMPLE_MUTEXES 1 77 78 #endif /* __MUTEX_PRIVATE */ 79 80 #endif /* _VAX_MUTEX_H_ */ 81