1 /* Copyright (C) 2005-2017 Free Software Foundation, Inc. 2 Contributed by Richard Henderson <rth@redhat.com>. 3 4 This file is part of the GNU Offloading and Multi Processing Library 5 (libgomp). 6 7 Libgomp is free software; you can redistribute it and/or modify it 8 under the terms of the GNU General Public License as published by 9 the Free Software Foundation; either version 3, or (at your option) 10 any later version. 11 12 Libgomp is distributed in the hope that it will be useful, but WITHOUT ANY 13 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS 14 FOR A PARTICULAR PURPOSE. See the GNU General Public License for 15 more details. 16 17 Under Section 7 of GPL version 3, you are granted additional 18 permissions described in the GCC Runtime Library Exception, version 19 3.1, as published by the Free Software Foundation. 20 21 You should have received a copy of the GNU General Public License and 22 a copy of the GCC Runtime Library Exception along with this program; 23 see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 24 <http://www.gnu.org/licenses/>. */ 25 26 /* Provide target-specific access to the futex system call. */ 27 28 #ifdef __x86_64__ 29 # ifndef SYS_futex 30 # define SYS_futex 202 31 # endif 32 33 static inline void 34 futex_wait (int *addr, int val) 35 { 36 long res; 37 38 register long r10 __asm__("%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 __asm volatile ("syscall" 49 : "=a" (res) 50 : "0" (SYS_futex), "D" (addr), "S" (gomp_futex_wait), 51 "d" (val), "r" (r10) 52 : "r11", "rcx", "memory"); 53 } 54 } 55 56 static inline void 57 futex_wake (int *addr, int count) 58 { 59 long res; 60 61 __asm volatile ("syscall" 62 : "=a" (res) 63 : "0" (SYS_futex), "D" (addr), "S" (gomp_futex_wake), 64 "d" (count) 65 : "r11", "rcx", "memory"); 66 if (__builtin_expect (res == -ENOSYS, 0)) 67 { 68 gomp_futex_wait &= ~FUTEX_PRIVATE_FLAG; 69 gomp_futex_wake &= ~FUTEX_PRIVATE_FLAG; 70 __asm volatile ("syscall" 71 : "=a" (res) 72 : "0" (SYS_futex), "D" (addr), "S" (gomp_futex_wake), 73 "d" (count) 74 : "r11", "rcx", "memory"); 75 } 76 } 77 #else 78 # ifndef SYS_futex 79 # define SYS_futex 240 80 # endif 81 82 static inline void 83 futex_wait (int *addr, int val) 84 { 85 long res; 86 87 __asm volatile ("int $0x80" 88 : "=a" (res) 89 : "0" (SYS_futex), "b" (addr), "c" (gomp_futex_wait), 90 "d" (val), "S" (0) 91 : "memory"); 92 if (__builtin_expect (res == -ENOSYS, 0)) 93 { 94 gomp_futex_wait &= ~FUTEX_PRIVATE_FLAG; 95 gomp_futex_wake &= ~FUTEX_PRIVATE_FLAG; 96 __asm volatile ("int $0x80" 97 : "=a" (res) 98 : "0" (SYS_futex), "b" (addr), "c" (gomp_futex_wait), 99 "d" (val), "S" (0) 100 : "memory"); 101 } 102 } 103 104 static inline void 105 futex_wake (int *addr, int count) 106 { 107 long res; 108 109 __asm volatile ("int $0x80" 110 : "=a" (res) 111 : "0" (SYS_futex), "b" (addr), "c" (gomp_futex_wake), 112 "d" (count) 113 : "memory"); 114 if (__builtin_expect (res == -ENOSYS, 0)) 115 { 116 gomp_futex_wait &= ~FUTEX_PRIVATE_FLAG; 117 gomp_futex_wake &= ~FUTEX_PRIVATE_FLAG; 118 __asm volatile ("int $0x80" 119 : "=a" (res) 120 : "0" (SYS_futex), "b" (addr), "c" (gomp_futex_wake), 121 "d" (count) 122 : "memory"); 123 } 124 } 125 #endif /* __x86_64__ */ 126 127 static inline void 128 cpu_relax (void) 129 { 130 __builtin_ia32_pause (); 131 } 132