1 /* Copyright (C) 2011-2015 Free Software Foundation, Inc. 2 Contributed by Walter Lee (walt@tilera.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 #include <sys/syscall.h> 29 #include <linux/futex.h> 30 31 static inline void 32 sys_futex0 (int *addr, int op, int val) 33 { 34 long _sys_result; 35 long _clobber_r2, _clobber_r3, _clobber_r4, _clobber_r5, _clobber_r10; 36 int err; 37 38 __asm__ __volatile__ ( 39 "swint1" 40 : "=R00" (_sys_result), "=R01" (err), "=R02" (_clobber_r2), 41 "=R03" (_clobber_r3), "=R04" (_clobber_r4), "=R05" (_clobber_r5), 42 "=R10" (_clobber_r10) 43 : "R10" (SYS_futex), "R00" (addr), "R01" (op), "R02" (val), 44 "R03" (0) 45 : "r6", "r7", 46 "r8", "r9", "r11", "r12", "r13", "r14", "r15", 47 "r16", "r17", "r18", "r19", "r20", "r21", "r22", "r23", 48 "r24", "r25", "r26", "r27", "r28", "r29", "memory"); 49 } 50 51 static inline void 52 futex_wait (int *addr, int val) 53 { 54 sys_futex0 (addr, FUTEX_WAIT, val); 55 } 56 57 static inline void 58 futex_wake (int *addr, int count) 59 { 60 sys_futex0 (addr, FUTEX_WAKE, count); 61 } 62 63 static inline void 64 cpu_relax (void) 65 { 66 __asm volatile ("" : : : "memory"); 67 } 68 69 static inline void 70 atomic_write_barrier (void) 71 { 72 __sync_synchronize (); 73 } 74