about summary refs log tree commit diff
path: root/linuxthreads/sysdeps/i386/i686/pt-machine.h
blob: 92798ac8b9a4a9de13a445b88be7058fecda1e17 (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
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
/* Machine-dependent pthreads configuration and inline functions.
   i686 version.
   Copyright (C) 1996, 1997, 1998, 2000 Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Contributed by Richard Henderson <rth@tamu.edu>.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Library General Public License as
   published by the Free Software Foundation; either version 2 of the
   License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Library General Public License for more details.

   You should have received a copy of the GNU Library General Public
   License along with the GNU C Library; see the file COPYING.LIB.  If not,
   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, USA.  */

#ifndef PT_EI
# define PT_EI extern inline
#endif
#include "kernel-features.h"

/* Get some notion of the current stack.  Need not be exactly the top
   of the stack, just something somewhere in the current frame.  */
#define CURRENT_STACK_FRAME  stack_pointer
register char * stack_pointer __asm__ ("%esp");


/* Spinlock implementation; required.  */
PT_EI long int
testandset (int *spinlock)
{
  long int ret;

  __asm__ __volatile__ (
	"xchgl %0, %1"
	: "=r"(ret), "=m"(*spinlock)
	: "0"(1), "m"(*spinlock)
	: "memory");

  return ret;
}


/* Compare-and-swap for semaphores.  It's always available on i686.  */
#define HAS_COMPARE_AND_SWAP

PT_EI int
__compare_and_swap (long int *p, long int oldval, long int newval)
{
  char ret;
  long int readval;

  __asm__ __volatile__ ("lock; cmpxchgl %3, %1; sete %0"
			: "=q" (ret), "=m" (*p), "=a" (readval)
			: "r" (newval), "m" (*p), "a" (oldval)
			: "memory");
  return ret;
}

#if __ASSUME_LDT_WORKS > 0
#include "../useldt.h"
#endif