ia64/xen-unstable

view xen/include/asm-x86/rwlock.h @ 18669:7989e3999e83

x86, spinlock: Get rid of .text.lock out-of-line section.

We don't care about code bloat now that spinlock operations are not
inlined into callers. This will make backtraces easier to read.

Signed-off-by: Keir Fraser <keir.fraser@citrix.com>
author Keir Fraser <keir.fraser@citrix.com>
date Mon Oct 20 17:17:55 2008 +0100 (2008-10-20)
parents 94a63704b6c4
children
line source
1 /* include/asm-x86/rwlock.h
2 *
3 * Helpers used by both rw spinlocks and rw semaphores.
4 *
5 * Based in part on code from semaphore.h and
6 * spinlock.h Copyright 1996 Linus Torvalds.
7 *
8 * Copyright 1999 Red Hat, Inc.
9 *
10 * Written by Benjamin LaHaise.
11 *
12 * This program is free software; you can redistribute it and/or
13 * modify it under the terms of the GNU General Public License
14 * as published by the Free Software Foundation; either version
15 * 2 of the License, or (at your option) any later version.
16 */
17 #ifndef _ASM_X86_RWLOCK_H
18 #define _ASM_X86_RWLOCK_H
20 #define RW_LOCK_BIAS 0x01000000
21 #define RW_LOCK_BIAS_STR "0x01000000"
23 #define __build_read_lock_ptr(rw, helper) \
24 asm volatile(LOCK "subl $1,(%0)\n\t" \
25 "jns 1f\n\t" \
26 "call " helper "\n\t" \
27 "1:\n" \
28 ::"a" (rw) : "memory")
30 #define __build_read_lock_const(rw, helper) \
31 asm volatile(LOCK "subl $1,%0\n\t" \
32 "jns 1f\n\t" \
33 "push %%"__OP"ax\n\t" \
34 "lea %0,%%"__OP"ax\n\t" \
35 "call " helper "\n\t" \
36 "pop %%"__OP"ax\n\t" \
37 "1:\n" \
38 :"=m" (*(volatile int *)rw) : : "memory")
40 #define __build_read_lock(rw, helper) do { \
41 if (__builtin_constant_p(rw)) \
42 __build_read_lock_const(rw, helper); \
43 else \
44 __build_read_lock_ptr(rw, helper); \
45 } while (0)
47 #define __build_write_lock_ptr(rw, helper) \
48 asm volatile(LOCK "subl $" RW_LOCK_BIAS_STR ",(%0)\n\t" \
49 "jz 1f\n\t" \
50 "call " helper "\n\t" \
51 "1:\n" \
52 ::"a" (rw) : "memory")
54 #define __build_write_lock_const(rw, helper) \
55 asm volatile(LOCK "subl $" RW_LOCK_BIAS_STR ",(%0)\n\t" \
56 "jz 1f\n\t" \
57 "push %%"__OP"ax\n\t" \
58 "lea %0,%%"__OP"ax\n\t" \
59 "call " helper "\n\t" \
60 "pop %%"__OP"ax\n\t" \
61 "1:\n" \
62 :"=m" (*(volatile int *)rw) : : "memory")
64 #define __build_write_lock(rw, helper) do { \
65 if (__builtin_constant_p(rw)) \
66 __build_write_lock_const(rw, helper); \
67 else \
68 __build_write_lock_ptr(rw, helper); \
69 } while (0)
71 #endif