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/* Copyright (C) 2005-2022 Free Software Foundation, Inc.
Contributed by Jakub Jelinek <jakub@redhat.com>.
This file is part of the GNU Offloading and Multi Processing Library
(libgomp).
Libgomp is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3, or (at your option)
any later version.
Libgomp is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE. See the GNU General Public License for
more details.
Under Section 7 of GPL version 3, you are granted additional
permissions described in the GCC Runtime Library Exception, version
3.1, as published by the Free Software Foundation.
You should have received a copy of the GNU General Public License and
a copy of the GCC Runtime Library Exception along with this program;
see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
<http://www.gnu.org/licenses/>. */
/* Provide target-specific access to the futex system call. */
#include <sys/syscall.h>
static inline long
sys_futex0 (int *addr, int op, int val)
{
register long int gpr2 __asm__ ("2");
register long int gpr3 __asm__ ("3");
register long int gpr4 __asm__ ("4");
register long int gpr5 __asm__ ("5");
gpr2 = (long) addr;
gpr3 = op;
gpr4 = val;
gpr5 = 0;
__asm volatile ("svc %b1"
: "=d" (gpr2)
: "i" (SYS_futex),
"0" (gpr2), "d" (gpr3), "d" (gpr4), "d" (gpr5)
: "memory");
return gpr2;
}
static inline void
futex_wait (int *addr, int val)
{
long err = sys_futex0 (addr, gomp_futex_wait, val);
if (__builtin_expect (err == -ENOSYS, 0))
{
gomp_futex_wait &= ~FUTEX_PRIVATE_FLAG;
gomp_futex_wake &= ~FUTEX_PRIVATE_FLAG;
sys_futex0 (addr, gomp_futex_wait, val);
}
}
static inline void
futex_wake (int *addr, int count)
{
long err = sys_futex0 (addr, gomp_futex_wake, count);
if (__builtin_expect (err == -ENOSYS, 0))
{
gomp_futex_wait &= ~FUTEX_PRIVATE_FLAG;
gomp_futex_wake &= ~FUTEX_PRIVATE_FLAG;
sys_futex0 (addr, gomp_futex_wake, count);
}
}
static inline void
cpu_relax (void)
{
__asm volatile ("" : : : "memory");
}
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