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/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Atomics xchg/cmpxchg for PKUnity SoC and UniCore ISA
*
* Copyright (C) 2001-2012 GUAN Xue-tao
*/
#ifndef __UNICORE_CMPXCHG_H__
#define __UNICORE_CMPXCHG_H__
/*
* Generate a link failure on undefined symbol if the pointer points to a value
* of unsupported size.
*/
extern void __xchg_bad_pointer(void);
static inline unsigned long __xchg(unsigned long x, volatile void *ptr,
int size)
{
unsigned long ret;
switch (size) {
case 1:
asm volatile("swapb %0, %1, [%2]"
: "=&r" (ret)
: "r" (x), "r" (ptr)
: "memory", "cc");
break;
case 4:
asm volatile("swapw %0, %1, [%2]"
: "=&r" (ret)
: "r" (x), "r" (ptr)
: "memory", "cc");
break;
default:
__xchg_bad_pointer();
}
return ret;
}
#define xchg(ptr, x) \
((__typeof__(*(ptr)))__xchg((unsigned long)(x), (ptr), sizeof(*(ptr))))
#include <asm-generic/cmpxchg-local.h>
/*
* cmpxchg_local and cmpxchg64_local are atomic wrt current CPU. Always make
* them available.
*/
#define cmpxchg_local(ptr, o, n) \
((__typeof__(*(ptr)))__cmpxchg_local_generic((ptr), \
(unsigned long)(o), (unsigned long)(n), sizeof(*(ptr))))
#define cmpxchg64_local(ptr, o, n) \
__cmpxchg64_local_generic((ptr), (o), (n))
#include <asm-generic/cmpxchg.h>
#endif /* __UNICORE_CMPXCHG_H__ */
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