1 /* $NetBSD: mutex.h,v 1.1 2014/09/03 19:34:26 matt 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 _OR1K_MUTEX_H_ 33 #define _OR1K_MUTEX_H_ 34 35 #ifndef __MUTEX_PRIVATE 36 37 struct kmutex { 38 uintptr_t mtx_pad1; 39 }; 40 41 #else /* __MUTEX_PRIVATE */ 42 43 struct kmutex { 44 union { 45 /* Adaptive mutex */ 46 volatile uintptr_t mtxa_owner; 47 48 /* Spin mutex */ 49 struct { 50 /* 51 * Since the low bit of mtax_owner is used to flag this 52 * mutex as a spin mutex, we can't use the first byte 53 * or the last byte to store the ipl or lock values. 54 */ 55 volatile uint8_t mtxs_dummy; 56 ipl_cookie_t mtxs_ipl; 57 __cpu_simple_lock_t mtxs_lock; 58 volatile uint8_t mtxs_unused; 59 } s; 60 } u; 61 }; 62 63 #define mtx_owner u.mtxa_owner 64 #define mtx_ipl u.s.mtxs_ipl 65 #define mtx_lock u.s.mtxs_lock 66 67 #if 0 68 #define __HAVE_MUTEX_STUBS 1 69 #define __HAVE_SPIN_MUTEX_STUBS 1 70 #endif 71 #define __HAVE_SIMPLE_MUTEXES 1 72 73 /* 74 * MUTEX_RECEIVE: no memory barrier required; we're synchronizing against 75 * interrupts, not multiple processors. 76 */ 77 #ifdef MULTIPROCESSOR 78 #define MUTEX_RECEIVE(mtx) membar_consumer() 79 #else 80 #define MUTEX_RECEIVE(mtx) /* nothing */ 81 #endif 82 83 /* 84 * MUTEX_GIVE: no memory barrier required; same reason. 85 */ 86 #ifdef MULTIPROCESSOR 87 #define MUTEX_GIVE(mtx) membar_producer() 88 #else 89 #define MUTEX_GIVE(mtx) /* nothing */ 90 #endif 91 92 #define MUTEX_CAS(p, o, n) \ 93 (atomic_cas_ulong((volatile unsigned long *)(p), (o), (n)) == (o)) 94 95 #endif /* __MUTEX_PRIVATE */ 96 97 #endif /* _OR1K_MUTEX_H_ */ 98