| 1 | /* $NetBSD: mutex.h,v 1.6 2009/04/24 17:49:51 ad Exp $ */ |
| 2 | |
| 3 | /*- |
| 4 | * Copyright (c) 2002, 2006, 2009 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 _X86_MUTEX_H_ |
| 33 | #define _X86_MUTEX_H_ |
| 34 | |
| 35 | struct kmutex { |
| 36 | union { |
| 37 | volatile uintptr_t mtxa_owner; |
| 38 | #ifdef __MUTEX_PRIVATE |
| 39 | struct { |
| 40 | volatile uint8_t mtxs_dummy; |
| 41 | ipl_cookie_t mtxs_ipl; |
| 42 | __cpu_simple_lock_t mtxs_lock; |
| 43 | volatile uint8_t mtxs_unused; |
| 44 | } s; |
| 45 | #endif |
| 46 | } u; |
| 47 | }; |
| 48 | |
| 49 | #ifdef __MUTEX_PRIVATE |
| 50 | |
| 51 | #define mtx_owner u.mtxa_owner |
| 52 | #define mtx_ipl u.s.mtxs_ipl |
| 53 | #define mtx_lock u.s.mtxs_lock |
| 54 | |
| 55 | #define __HAVE_MUTEX_STUBS 1 |
| 56 | #define __HAVE_SPIN_MUTEX_STUBS 1 |
| 57 | #define __HAVE_SIMPLE_MUTEXES 1 |
| 58 | |
| 59 | /* |
| 60 | * MUTEX_RECEIVE: technically, no memory barrier is required |
| 61 | * as 'ret' implies a load fence. However we need this to |
| 62 | * handle a bug with some Opteron revisions. See patch.c, |
| 63 | * lock_stubs.S. |
| 64 | */ |
| 65 | #define MUTEX_RECEIVE(mtx) membar_consumer() |
| 66 | |
| 67 | /* |
| 68 | * MUTEX_GIVE: no memory barrier required, as _lock_cas() will take care of it. |
| 69 | */ |
| 70 | #define MUTEX_GIVE(mtx) /* nothing */ |
| 71 | |
| 72 | #define MUTEX_CAS(p, o, n) \ |
| 73 | (_atomic_cas_ulong((volatile unsigned long *)(p), (o), (n)) == (o)) |
| 74 | |
| 75 | unsigned long _atomic_cas_ulong(volatile unsigned long *, |
| 76 | unsigned long, unsigned long); |
| 77 | |
| 78 | #endif /* __MUTEX_PRIVATE */ |
| 79 | |
| 80 | #endif /* _X86_MUTEX_H_ */ |
| 81 | |