linux/arch/nios2/include/asm/cmpxchg.h

62 lines
1.2 KiB
C

/*
* Copyright (C) 2004 Microtronix Datacom Ltd.
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*/
#ifndef _ASM_NIOS2_CMPXCHG_H
#define _ASM_NIOS2_CMPXCHG_H
#include <linux/irqflags.h>
#define xchg(ptr, x) \
((__typeof__(*(ptr)))__xchg((unsigned long)(x), (ptr), sizeof(*(ptr))))
struct __xchg_dummy { unsigned long a[100]; };
#define __xg(x) ((volatile struct __xchg_dummy *)(x))
static inline unsigned long __xchg(unsigned long x, volatile void *ptr,
int size)
{
unsigned long tmp, flags;
local_irq_save(flags);
switch (size) {
case 1:
__asm__ __volatile__(
"ldb %0, %2\n"
"stb %1, %2\n"
: "=&r" (tmp)
: "r" (x), "m" (*__xg(ptr))
: "memory");
break;
case 2:
__asm__ __volatile__(
"ldh %0, %2\n"
"sth %1, %2\n"
: "=&r" (tmp)
: "r" (x), "m" (*__xg(ptr))
: "memory");
break;
case 4:
__asm__ __volatile__(
"ldw %0, %2\n"
"stw %1, %2\n"
: "=&r" (tmp)
: "r" (x), "m" (*__xg(ptr))
: "memory");
break;
}
local_irq_restore(flags);
return tmp;
}
#include <asm-generic/cmpxchg.h>
#include <asm-generic/cmpxchg-local.h>
#endif /* _ASM_NIOS2_CMPXCHG_H */