/*
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* Atomics xchg/cmpxchg for PKUnity SoC and UniCore ISA
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*
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* Copyright (C) 2001-2012 GUAN Xue-tao
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#ifndef __UNICORE_CMPXCHG_H__
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#define __UNICORE_CMPXCHG_H__
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/*
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* Generate a link failure on undefined symbol if the pointer points to a value
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* of unsupported size.
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*/
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extern void __xchg_bad_pointer(void);
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static inline unsigned long __xchg(unsigned long x, volatile void *ptr,
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int size)
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{
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unsigned long ret;
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switch (size) {
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case 1:
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asm volatile("swapb %0, %1, [%2]"
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: "=&r" (ret)
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: "r" (x), "r" (ptr)
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: "memory", "cc");
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break;
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case 4:
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asm volatile("swapw %0, %1, [%2]"
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: "=&r" (ret)
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: "r" (x), "r" (ptr)
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: "memory", "cc");
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break;
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default:
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__xchg_bad_pointer();
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}
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return ret;
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}
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#define xchg(ptr, x) \
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((__typeof__(*(ptr)))__xchg((unsigned long)(x), (ptr), sizeof(*(ptr))))
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#include <asm-generic/cmpxchg-local.h>
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/*
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* cmpxchg_local and cmpxchg64_local are atomic wrt current CPU. Always make
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* them available.
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*/
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#define cmpxchg_local(ptr, o, n) \
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((__typeof__(*(ptr)))__cmpxchg_local_generic((ptr), \
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(unsigned long)(o), (unsigned long)(n), sizeof(*(ptr))))
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#define cmpxchg64_local(ptr, o, n) \
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__cmpxchg64_local_generic((ptr), (o), (n))
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#include <asm-generic/cmpxchg.h>
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#endif /* __UNICORE_CMPXCHG_H__ */
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