1 /* Copyright (C) 2005, 2008, 2009 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 General Public License as published by 8 the Free Software Foundation; either version 3, or (at your option) 9 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 General Public License for 14 more details. 15 16 Under Section 7 of GPL version 3, you are granted additional 17 permissions described in the GCC Runtime Library Exception, version 18 3.1, as published by the Free Software Foundation. 19 20 You should have received a copy of the GNU General Public License and 21 a copy of the GCC Runtime Library Exception along with this program; 22 see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 23 <http://www.gnu.org/licenses/>. */ 24 25 /* Provide target-specific access to the futex system call. */ 26 27 #ifdef __LP64__ 28 # ifndef SYS_futex 29 # define SYS_futex 202 30 # endif 31 32 static inline void 33 futex_wait (int *addr, int val) 34 { 35 register long r10 __asm__("%r10"); 36 long res; 37 38 r10 = 0; 39 __asm volatile ("syscall" 40 : "=a" (res) 41 : "0" (SYS_futex), "D" (addr), "S" (gomp_futex_wait), 42 "d" (val), "r" (r10) 43 : "r11", "rcx", "memory"); 44 if (__builtin_expect (res == -ENOSYS, 0)) 45 { 46 gomp_futex_wait &= ~FUTEX_PRIVATE_FLAG; 47 gomp_futex_wake &= ~FUTEX_PRIVATE_FLAG; 48 r10 = 0; 49 __asm volatile ("syscall" 50 : "=a" (res) 51 : "0" (SYS_futex), "D" (addr), "S" (gomp_futex_wait), 52 "d" (val), "r" (r10) 53 : "r11", "rcx", "memory"); 54 } 55 } 56 57 static inline void 58 futex_wake (int *addr, int count) 59 { 60 long res; 61 62 __asm volatile ("syscall" 63 : "=a" (res) 64 : "0" (SYS_futex), "D" (addr), "S" (gomp_futex_wake), 65 "d" (count) 66 : "r11", "rcx", "memory"); 67 if (__builtin_expect (res == -ENOSYS, 0)) 68 { 69 gomp_futex_wait &= ~FUTEX_PRIVATE_FLAG; 70 gomp_futex_wake &= ~FUTEX_PRIVATE_FLAG; 71 __asm volatile ("syscall" 72 : "=a" (res) 73 : "0" (SYS_futex), "D" (addr), "S" (gomp_futex_wake), 74 "d" (count) 75 : "r11", "rcx", "memory"); 76 } 77 } 78 #else 79 # ifndef SYS_futex 80 # define SYS_futex 240 81 # endif 82 83 # ifdef __PIC__ 84 85 static inline long 86 sys_futex0 (int *addr, int op, int val) 87 { 88 long res; 89 90 __asm volatile ("xchgl\t%%ebx, %2\n\t" 91 "int\t$0x80\n\t" 92 "xchgl\t%%ebx, %2" 93 : "=a" (res) 94 : "0"(SYS_futex), "r" (addr), "c"(op), 95 "d"(val), "S"(0) 96 : "memory"); 97 return res; 98 } 99 100 # else 101 102 static inline long 103 sys_futex0 (int *addr, int op, int val) 104 { 105 long res; 106 107 __asm volatile ("int $0x80" 108 : "=a" (res) 109 : "0"(SYS_futex), "b" (addr), "c"(op), 110 "d"(val), "S"(0) 111 : "memory"); 112 return res; 113 } 114 115 # endif /* __PIC__ */ 116 117 static inline void 118 futex_wait (int *addr, int val) 119 { 120 long res = sys_futex0 (addr, gomp_futex_wait, val); 121 if (__builtin_expect (res == -ENOSYS, 0)) 122 { 123 gomp_futex_wait &= ~FUTEX_PRIVATE_FLAG; 124 gomp_futex_wake &= ~FUTEX_PRIVATE_FLAG; 125 sys_futex0 (addr, gomp_futex_wait, val); 126 } 127 } 128 129 static inline void 130 futex_wake (int *addr, int count) 131 { 132 long res = sys_futex0 (addr, gomp_futex_wake, count); 133 if (__builtin_expect (res == -ENOSYS, 0)) 134 { 135 gomp_futex_wait &= ~FUTEX_PRIVATE_FLAG; 136 gomp_futex_wake &= ~FUTEX_PRIVATE_FLAG; 137 sys_futex0 (addr, gomp_futex_wake, count); 138 } 139 } 140 141 #endif /* __LP64__ */ 142 143 static inline void 144 cpu_relax (void) 145 { 146 __asm volatile ("rep; nop" : : : "memory"); 147 } 148 149 static inline void 150 atomic_write_barrier (void) 151 { 152 __sync_synchronize (); 153 } 154