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/* Low-level functions for atomic operations. Mips version.
Copyright (C) 2001 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 _MIPS_ATOMICITY_H
#define _MIPS_ATOMICITY_H 1
#include <sgidefs.h>
#include <inttypes.h>
#if (_MIPS_ISA >= _MIPS_ISA_MIPS2)
static inline int
__attribute__ ((unused))
exchange_and_add (volatile uint32_t *mem, int val)
{
int result, tmp;
__asm__ __volatile__
("/* Inline exchange & add */\n\t"
"1:\n\t"
"ll %0,%3\n\t"
"addu %1,%4,%0\n\t"
"sc %1,%2\n\t"
"beqz %1,1b\n\t"
"/* End exchange & add */"
: "=&r"(result), "=&r"(tmp), "=m"(*mem)
: "m" (*mem), "r"(val)
: "memory");
return result;
}
static inline void
__attribute__ ((unused))
atomic_add (volatile uint32_t *mem, int val)
{
int result;
__asm__ __volatile__
("/* Inline atomic add */\n\t"
"1:\n\t"
"ll %0,%2\n\t"
"addu %0,%3,%0\n\t"
"sc %0,%1\n\t"
"beqz %0,1b\n\t"
"/* End atomic add */"
: "=&r"(result), "=m"(*mem)
: "m" (*mem), "r"(val)
: "memory");
}
static inline int
__attribute__ ((unused))
compare_and_swap (volatile long int *p, long int oldval, long int newval)
{
long int ret;
__asm__ __volatile__
("/* Inline compare & swap */\n\t"
"1:\n\t"
"ll %0,%4\n\t"
".set push\n"
".set noreorder\n\t"
"bne %0,%2,2f\n\t"
"move %0,%3\n\t"
".set pop\n\t"
"sc %0,%1\n\t"
"beqz %0,1b\n"
"2:\n\t"
"/* End compare & swap */"
: "=&r" (ret), "=m" (*p)
: "r" (oldval), "r" (newval), "m" (*p)
: "memory");
return ret;
}
#else /* (_MIPS_ISA >= _MIPS_ISA_MIPS2) */
#warning MIPS I atomicity functions are not atomic
static inline int
__attribute__ ((unused))
exchange_and_add (volatile uint32_t *mem, int val)
{
int result = *mem;
*mem += val;
return result;
}
static inline void
__attribute__ ((unused))
atomic_add (volatile uint32_t *mem, int val)
{
*mem += val;
}
static inline int
__attribute__ ((unused))
compare_and_swap (volatile long int *p, long int oldval, long int newval)
{
if (*p != oldval)
return 0;
*p = newval;
return 1;
}
#endif /* !(_MIPS_ISA >= _MIPS_ISA_MIPS2) */
#endif /* atomicity.h */
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