libgomp/config/linux/tile/futex.h

   1 /* Copyright (C) 2011-2020 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 }