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/* Low-level functions for atomic operations. AM33 version.
Copyright 1999-2013 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Alexandre Oliva <aoliva@redhat.com>.
Based on ../sparc/sparc32/atomicity.h
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library. If not, see
<http://www.gnu.org/licenses/>. */
#ifndef _ATOMICITY_H
#define _ATOMICITY_H 1
#include <inttypes.h>
#include <stdint.h>
#define __acquire_lock(lock) \
__asm__ __volatile__("1: bset %1, (%0)\n\t" \
" beq 1b" \
: : "a" (&(lock)), "d" (1) \
: "memory")
#define __release_lock(lock) lock = 0
static int
__attribute__ ((unused))
exchange_and_add (volatile uint32_t *mem, int val)
{
static unsigned char lock;
int result;
__acquire_lock (lock);
result = *mem;
*mem += val;
__release_lock (lock);
return result;
}
static void
__attribute__ ((unused))
atomic_add (volatile uint32_t *mem, int val)
{
static unsigned char lock;
__acquire_lock (lock);
*mem += val;
__release_lock (lock);
}
static int
__attribute__ ((unused))
compare_and_swap (volatile long int *p, long int oldval, long int newval)
{
static unsigned char lock;
int ret;
__acquire_lock (lock);
if (*p != oldval)
ret = 0;
else
{
*p = newval;
ret = 1;
}
__release_lock (lock);
return ret;
}
#endif /* atomicity.h */
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