Skip to content

HTTPS clone URL

Subversion checkout URL

You can clone with HTTPS or Subversion.

Download ZIP
Newer
Older
100644 84 lines (67 sloc) 2.741 kb
7310165 Face the music and do memory barriers sensibly.
Poul-Henning Kamp authored
1 /*-
2 * Copyright (c) 2010 Redpill Linpro AS
3 * All rights reserved.
4 *
5 * Author: Poul-Henning Kamp <phk@phk.freebsd.dk>
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 *
28 * $Id$
29 *
30 * Memory barriers
31 *
3efd84b Revisit the memory barriers, and try to catch some common platforms
Poul-Henning Kamp authored
32 * XXX: It is utterly braindamaged, that no standard facility for this
33 * XXX: is available. The "just use pthreads locking" excuse does not
34 * XXX: make sense, and does not apply to two unthreaded programs sharing
35 * XXX: a memory segment.
7310165 Face the music and do memory barriers sensibly.
Poul-Henning Kamp authored
36 */
37
38 #ifndef VMB_H_INCLUDED
39 #define VMB_H_INCLUDED
40
41 void vmb_pthread(void);
42
43 #if defined(__FreeBSD__)
3efd84b Revisit the memory barriers, and try to catch some common platforms
Poul-Henning Kamp authored
44
7310165 Face the music and do memory barriers sensibly.
Poul-Henning Kamp authored
45 #include <sys/types.h>
46 #include <machine/atomic.h>
3efd84b Revisit the memory barriers, and try to catch some common platforms
Poul-Henning Kamp authored
47 #define VMB() mb()
48 #define VWMB() wmb()
49 #define VRMB() rmb()
50
51 #elif defined(__amd64__) && defined(__GNUC__)
52
53 #define VMB() __asm __volatile("mfence;" : : : "memory")
54 #define VWMB() __asm __volatile("sfence;" : : : "memory")
55 #define VRMB() __asm __volatile("lfence;" : : : "memory")
56
57 #elif defined(__arm__)
58
a22e7cc Whitespace cleanup
Poul-Henning Kamp authored
59 #define VMB()
60 #define VWMB()
61 #define VRMB()
3efd84b Revisit the memory barriers, and try to catch some common platforms
Poul-Henning Kamp authored
62
63 #elif defined(__i386__) && defined(__GNUC__)
64
65 #define VMB() __asm __volatile("lock; addl $0,(%%esp)" : : : "memory")
66 #define VWMB() __asm __volatile("lock; addl $0,(%%esp)" : : : "memory")
67 #define VRMB() __asm __volatile("lock; addl $0,(%%esp)" : : : "memory")
68
69 #elif defined(__sparc64__) && defined(__GNUC__)
70
71 #define VMB() __asm__ __volatile__ ("membar #MemIssue": : :"memory")
72 #define VWMB() VMB()
73 #define VRMB() VMB()
74
7310165 Face the music and do memory barriers sensibly.
Poul-Henning Kamp authored
75 #else
3efd84b Revisit the memory barriers, and try to catch some common platforms
Poul-Henning Kamp authored
76
77 #define VMB() vmb_pthread()
78 #define VWMB() vmb_pthread()
79 #define VRMB() vmb_pthread()
80
7310165 Face the music and do memory barriers sensibly.
Poul-Henning Kamp authored
81 #endif
82
83 #endif /* VMB_H_INCLUDED */
Something went wrong with that request. Please try again.