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 | |