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/*
* Copyright (C) 2016-2017 Andes Technology, Inc.
* Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball.
*/
/* POSIX spinlock implementation.
Copyright (C) 2000 Free Software Foundation, Inc.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public License as
published by the Free Software Foundation; either version 2.1 of the
License, or (at your option) any later version.
The GNU C Library 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; see the file COPYING.LIB. If not,
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#include <errno.h>
#include <pthread.h>
#include "internals.h"
int
__pthread_spin_lock (pthread_spinlock_t *lock)
{
unsigned int val ;
unsigned int temp ;
unsigned int offset = 0 ;
__asm__ __volatile__ (
"1:\n\t"
"llw %0, [%1 + %2 << 0]\n\t"
"bnez %0, 1b\n\t"
"movi %3, #0x1\n\t"
"scw %3, [%1 + %2 << 0]\n\t"
"beqz %3, 1b\n\t"
: "=&r" (val)
: "r" (lock), "r" (offset), "r" (temp)
: "memory" ) ;
return 0 ;
}
weak_alias (__pthread_spin_lock, pthread_spin_lock)
int
__pthread_spin_trylock (pthread_spinlock_t *lock)
{
unsigned int val ;
unsigned int temp ;
unsigned int offset = 0 ;
__asm__ __volatile__ (
"llw %0, [%1 + %2 << 0]\n\t"
"bnez %0, 1f\n\t"
"movi %3, #0x1\n\t"
"scw %3, [%1 + %2 << 0]\n\t"
"beqz %3, 1f\n\t"
"movi %0, #0x0\n\t"
"b 2f\n\t"
"1:\n\t"
"movi %0, #16\n\t"
"2:\n\t"
: "=&r" (val)
: "r" (lock), "r" (offset), "r" (temp)
: "memory" ) ;
return val;
}
weak_alias (__pthread_spin_trylock, pthread_spin_trylock)
int
__pthread_spin_unlock (pthread_spinlock_t *lock)
{
return *lock = 0;
}
weak_alias (__pthread_spin_unlock, pthread_spin_unlock)
int
__pthread_spin_init (pthread_spinlock_t *lock, int pshared)
{
/* We can ignore the `pshared' parameter. Since we are busy-waiting
all processes which can access the memory location `lock' points
to can use the spinlock. */
return *lock = 0;
}
weak_alias (__pthread_spin_init, pthread_spin_init)
int
__pthread_spin_destroy (pthread_spinlock_t *lock)
{
/* Nothing to do. */
return 0;
}
weak_alias (__pthread_spin_destroy, pthread_spin_destroy)
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