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/* Low-level functions for atomic operations. ARM version.
Copyright (C) 1997, 1998, 1999, 2000 Free Software Foundation, Inc.
This file is part of the GNU C Library.
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; see the file COPYING.LIB. If not,
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#ifndef _ATOMICITY_H
#define _ATOMICITY_H 1
#include <inttypes.h>
static inline int
__attribute__ ((unused))
exchange_and_add (volatile uint32_t *mem, int val)
{
int tmp1;
int tmp2;
int result;
__asm__ ("\n"
"0:\tldr\t%0,[%3]\n\t"
"add\t%1,%0,%4\n\t"
"swp\t%2,%1,[%3]\n\t"
"cmp\t%0,%2\n\t"
"swpne\t%1,%2,[%3]\n\t"
"bne\t0b"
: "=&r" (result), "=&r" (tmp1), "=&r" (tmp2)
: "r" (mem), "r"(val)
: "cc", "memory");
return result;
}
static inline void
__attribute__ ((unused))
atomic_add (volatile uint32_t *mem, int val)
{
int tmp1;
int tmp2;
int tmp3;
__asm__ ("\n"
"0:\tldr\t%0,[%3]\n\t"
"add\t%1,%0,%4\n\t"
"swp\t%2,%1,[%3]\n\t"
"cmp\t%0,%2\n\t"
"swpne\t%1,%2,[%3]\n\t"
"bne\t0b"
: "=&r" (tmp1), "=&r" (tmp2), "=&r" (tmp3)
: "r" (mem), "r"(val)
: "cc", "memory");
}
static inline int
__attribute__ ((unused))
compare_and_swap (volatile long int *p, long int oldval, long int newval)
{
int result, tmp;
__asm__ ("\n"
"0:\tldr\t%1,[%2]\n\t"
"mov\t%0,#0\n\t"
"cmp\t%1,%4\n\t"
"bne\t1f\n\t"
"swp\t%0,%3,[%2]\n\t"
"cmp\t%1,%0\n\t"
"swpne\t%1,%0,[%2]\n\t"
"bne\t0b\n\t"
"mov\t%0,#1\n"
"1:"
: "=&r" (result), "=&r" (tmp)
: "r" (p), "r" (newval), "r" (oldval)
: "cc", "memory");
}
#endif /* atomicity.h */
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