blob: 28a080d231191ff32e5d97c030923943bb0fb4d4 (
plain) (
blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
|
/* include/asm-x86_64/rwlock.h
*
* Helpers used by both rw spinlocks and rw semaphores.
*
* Based in part on code from semaphore.h and
* spinlock.h Copyright 1996 Linus Torvalds.
*
* Copyright 1999 Red Hat, Inc.
* Copyright 2001,2002 SuSE labs
*
* Written by Benjamin LaHaise.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#ifndef _ASM_X86_64_RWLOCK_H
#define _ASM_X86_64_RWLOCK_H
#define RW_LOCK_BIAS 0x01000000
#define RW_LOCK_BIAS_STR "0x01000000"
#define __build_read_lock(rw) \
asm volatile(LOCK_PREFIX "subl $1,(%0)\n\t" \
"jns 1f\n" \
"call __read_lock_failed\n" \
"1:\n" \
::"D" (rw), "i" (RW_LOCK_BIAS) : "memory")
#define __build_write_lock(rw) \
asm volatile(LOCK_PREFIX "subl %1,(%0)\n\t" \
"jz 1f\n" \
"\tcall __write_lock_failed\n\t" \
"1:\n" \
::"D" (rw), "i" (RW_LOCK_BIAS) : "memory")
#endif
|
