libgomp/config/linux/mips/futex.h

   1 /* Copyright (C) 2005-2018 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 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
  30 #if !defined (SYS_futex)
  31 #define SYS_futex __NR_futex
  32 #endif
  33
  34 #define FUTEX_WAIT 0
  35 #define FUTEX_WAKE 1
  36
  37 #ifdef __mips16
  38 static void __attribute__((noinline,nomips16))
  39 #else
  40 static inline void
  41 #endif
  42 sys_futex0 (int *addr, int op, int val)
  43 {
  44   register unsigned long __v0 asm("$2");
  45   register unsigned long __a0 asm("$4") = (unsigned long) addr;
  46   register unsigned long __a1 asm("$5") = (unsigned long) op;
  47   register unsigned long __a2 asm("$6") = (unsigned long) val;
  48   register unsigned long __a3 asm("$7") = 0;
  49
  50   __asm volatile ("li $2, %6\n\t"
  51                   "syscall"
  52                   /* returns $a3 (errno), $v0 (return value) */
  53                   : "=r" (__v0), "=r" (__a3)
  54                   /* arguments in a0-a3, and syscall number */
  55                   : "r" (__a0), "r" (__a1), "r" (__a2), "r" (__a3),
  56                     "IK" (SYS_futex)
  57                   /* clobbers at, v1, t0-t9, memory */
  58                   : "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13", "$14",
  59                     "$15", "$24", "$25", "memory");
  60 }
  61
  62 static inline void
  63 futex_wait (int *addr, int val)
  64 {
  65   sys_futex0 (addr, FUTEX_WAIT, val);
  66 }
  67
  68 static inline void
  69 futex_wake (int *addr, int count)
  70 {
  71   sys_futex0 (addr, FUTEX_WAKE, count);
  72 }
  73
  74 static inline void
  75 cpu_relax (void)
  76 {
  77   __asm volatile ("" : : : "memory");
  78 }