1 /* Copyright (C) 2005-2013 Free Software Foundation, Inc. 2 Contributed by Ilie Garbacea <ilie@mips.com>, Chao-ying Fu <fu@mips.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 #include <sys/syscall.h> 28 #define FUTEX_WAIT 0 29 #define FUTEX_WAKE 1 30 31 #ifdef __mips16 32 static void __attribute__((noinline,nomips16)) 33 #else 34 static inline void 35 #endif 36 sys_futex0 (int *addr, int op, int val) 37 { 38 register unsigned long __v0 asm("$2"); 39 register unsigned long __a0 asm("$4") = (unsigned long) addr; 40 register unsigned long __a1 asm("$5") = (unsigned long) op; 41 register unsigned long __a2 asm("$6") = (unsigned long) val; 42 register unsigned long __a3 asm("$7") = 0; 43 44 __asm volatile ("li $2, %6\n\t" 45 "syscall" 46 /* returns $a3 (errno), $v0 (return value) */ 47 : "=r" (__v0), "=r" (__a3) 48 /* arguments in a0-a3, and syscall number */ 49 : "r" (__a0), "r" (__a1), "r" (__a2), "r" (__a3), 50 "IK" (SYS_futex) 51 /* clobbers at, v1, t0-t9, memory */ 52 : "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13", "$14", 53 "$15", "$24", "$25", "memory"); 54 } 55 56 static inline void 57 futex_wait (int *addr, int val) 58 { 59 sys_futex0 (addr, FUTEX_WAIT, val); 60 } 61 62 static inline void 63 futex_wake (int *addr, int count) 64 { 65 sys_futex0 (addr, FUTEX_WAKE, count); 66 } 67 68 static inline void 69 cpu_relax (void) 70 { 71 __asm volatile ("" : : : "memory"); 72 } 73