1 /* Machine-dependent pthreads configuration and inline functions.
2 x86-64 version.
3 Copyright (C) 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
4 This file is part of the GNU C Library.
5
6 The GNU C Library is free software; you can redistribute it and/or
7 modify it under the terms of the GNU Lesser General Public
8 License as published by the Free Software Foundation; either
9 version 2.1 of the License, or (at your option) any later version.
10
11 The GNU C Library is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Lesser General Public License for more details.
15
16 You should have received a copy of the GNU Lesser General Public
17 License along with the GNU C Library; if not, see
18 <http://www.gnu.org/licenses/>. */
19
20 #ifndef _PT_MACHINE_H
21 #define _PT_MACHINE_H 1
22
23 #include <features.h>
24
25 #ifndef __ASSEMBLER__
26 # include <stddef.h> /* For offsetof. */
27 # include <stdlib.h> /* For abort(). */
28 # include <asm/prctl.h>
29
30
31 # ifndef PT_EI
32 # define PT_EI __extern_always_inline
33 # endif
34
35 extern long int testandset (int *);
36 extern int __compare_and_swap (long int *, long int, long int);
37
38 /* Get some notion of the current stack. Need not be exactly the top
39 of the stack, just something somewhere in the current frame. */
40 # define CURRENT_STACK_FRAME stack_pointer
41 register char * stack_pointer __asm__ ("%rsp") __attribute_used__;
42
43
44 /* Spinlock implementation; required. */
45 PT_EI long int
testandset(int * __spinlock)46 testandset (int *__spinlock)
47 {
48 long int ret;
49
50 __asm__ __volatile__ (
51 "xchgl %k0, %1"
52 : "=r"(ret), "=m"(*__spinlock)
53 : "0"(1), "m"(*__spinlock)
54 : "memory");
55
56 return ret;
57 }
58
59
60 /* Compare-and-swap for semaphores. */
61 # define HAS_COMPARE_AND_SWAP
62
63 PT_EI int
__compare_and_swap(long int * __p,long int __oldval,long int __newval)64 __compare_and_swap (long int *__p, long int __oldval, long int __newval)
65 {
66 char ret;
67 long int readval;
68
69 __asm__ __volatile__ ("lock; cmpxchgq %3, %1; sete %0"
70 : "=q" (ret), "=m" (*__p), "=a" (readval)
71 : "r" (__newval), "m" (*__p), "a" (__oldval)
72 : "memory");
73 return ret;
74 }
75
76 #endif /* !__ASSEMBLER__ */
77
78 /* We want the OS to assign stack addresses. */
79 #define FLOATING_STACKS 1
80
81 /* Maximum size of the stack if the rlimit is unlimited. */
82 #define ARCH_STACK_MAX_SIZE 32*1024*1024
83
84 /* The ia32e really want some help to prevent overheating. */
85 #define BUSY_WAIT_NOP __asm__ ("rep; nop")
86
87 #endif /* pt-machine.h */
88