1 /* Copyright (C) 2005 Free Software Foundation, Inc.
2 Contributed by Richard Henderson <rth@redhat.com>.
3
4 This file is part of the GNU OpenMP Library (libgomp).
5
6 Libgomp is free software; you can redistribute it and/or modify it
7 under the terms of the GNU Lesser General Public License as published by
8 the Free Software Foundation; either version 2.1 of the License, or
9 (at your option) any later version.
10
11 Libgomp is distributed in the hope that it will be useful, but WITHOUT ANY
12 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
13 FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for
14 more details.
15
16 You should have received a copy of the GNU Lesser General Public License
17 along with libgomp; see the file COPYING.LIB. If not, write to the
18 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
19 MA 02110-1301, USA. */
20
21 /* As a special exception, if you link this library with other files, some
22 of which are compiled with GCC, to produce an executable, this library
23 does not by itself cause the resulting executable to be covered by the
24 GNU General Public License. This exception does not however invalidate
25 any other reasons why the executable file might be covered by the GNU
26 General Public License. */
27
28 /* Provide target-specific access to the futex system call. */
29
30 #define FUTEX_WAIT 0
31 #define FUTEX_WAKE 1
32
33 #ifdef __LP64__
34 # ifndef SYS_futex
35 # define SYS_futex 202
36 # endif
37
38 static inline void
futex_wait(int * addr,int val)39 futex_wait (int *addr, int val)
40 {
41 register long r10 __asm__("%r10") = 0;
42 long res;
43
44 __asm volatile ("syscall"
45 : "=a" (res)
46 : "0"(SYS_futex), "D" (addr), "S"(FUTEX_WAIT),
47 "d"(val), "r"(r10)
48 : "r11", "rcx", "memory");
49 }
50
51 static inline void
futex_wake(int * addr,int count)52 futex_wake (int *addr, int count)
53 {
54 long res;
55
56 __asm volatile ("syscall"
57 : "=a" (res)
58 : "0"(SYS_futex), "D" (addr), "S"(FUTEX_WAKE), "d"(count)
59 : "r11", "rcx", "memory");
60 }
61 #else
62 # ifndef SYS_futex
63 # define SYS_futex 240
64 # endif
65
66 # ifdef __PIC__
67
68 static inline void
sys_futex0(int * addr,int op,int val)69 sys_futex0 (int *addr, int op, int val)
70 {
71 long res;
72
73 __asm volatile ("xchgl\t%%ebx, %2\n\t"
74 "int\t$0x80\n\t"
75 "xchgl\t%%ebx, %2"
76 : "=a" (res)
77 : "0"(SYS_futex), "r" (addr), "c"(op),
78 "d"(val), "S"(0)
79 : "memory");
80 }
81
82 # else
83
84 static inline void
sys_futex0(int * addr,int op,int val)85 sys_futex0 (int *addr, int op, int val)
86 {
87 long res;
88
89 __asm volatile ("int $0x80"
90 : "=a" (res)
91 : "0"(SYS_futex), "b" (addr), "c"(op),
92 "d"(val), "S"(0)
93 : "memory");
94 }
95
96 # endif /* __PIC__ */
97
98 static inline void
futex_wait(int * addr,int val)99 futex_wait (int *addr, int val)
100 {
101 sys_futex0 (addr, FUTEX_WAIT, val);
102 }
103
104 static inline void
futex_wake(int * addr,int count)105 futex_wake (int *addr, int count)
106 {
107 sys_futex0 (addr, FUTEX_WAKE, count);
108 }
109
110 #endif /* __LP64__ */
111