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/*
* Atomic operations that C can't guarantee us. Useful for
* resource counting etc.
*
* But use these as seldom as possible since they are slower than
* regular operations.
*
* Copyright (C) 2004-2006 Atmel Corporation
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#ifndef __ASM_AVR32_CMPXCHG_H
#define __ASM_AVR32_CMPXCHG_H
#define xchg(ptr,x) \
((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))
extern void __xchg_called_with_bad_pointer(void);
static inline unsigned long xchg_u32(u32 val, volatile u32 *m)
{
u32 ret;
asm volatile("xchg %[ret], %[m], %[val]"
: [ret] "=&r"(ret), "=m"(*m)
: "m"(*m), [m] "r"(m), [val] "r"(val)
: "memory");
return ret;
}
static inline unsigned long __xchg(unsigned long x,
volatile void *ptr,
int size)
{
switch(size) {
case 4:
return xchg_u32(x, ptr);
default:
__xchg_called_with_bad_pointer();
return x;
}
}
static inline unsigned long __cmpxchg_u32(volatile int *m, unsigned long old,
unsigned long new)
{
__u32 ret;
asm volatile(
"1: ssrf 5\n"
" ld.w %[ret], %[m]\n"
" cp.w %[ret], %[old]\n"
" brne 2f\n"
" stcond %[m], %[new]\n"
" brne 1b\n"
"2:\n"
: [ret] "=&r"(ret), [m] "=m"(*m)
: "m"(m), [old] "ir"(old), [new] "r"(new)
: "memory", "cc");
return ret;
}
extern unsigned long __cmpxchg_u64_unsupported_on_32bit_kernels(
volatile int * m, unsigned long old, unsigned long new);
#define __cmpxchg_u64 __cmpxchg_u64_unsupported_on_32bit_kernels
/* This function doesn't exist, so you'll get a linker error
if something tries to do an invalid cmpxchg(). */
extern void __cmpxchg_called_with_bad_pointer(void);
static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old,
unsigned long new, int size)
{
switch (size) {
case 4:
return __cmpxchg_u32(ptr, old, new);
case 8:
return __cmpxchg_u64(ptr, old, new);
}
__cmpxchg_called_with_bad_pointer();
return old;
}
#define cmpxchg(ptr, old, new) \
((typeof(*(ptr)))__cmpxchg((ptr), (unsigned long)(old), \
(unsigned long)(new), \
sizeof(*(ptr))))
#include <asm-generic/cmpxchg-local.h>
static inline unsigned long __cmpxchg_local(volatile void *ptr,
unsigned long old,
unsigned long new, int size)
{
switch (size) {
case 4:
return __cmpxchg_u32(ptr, old, new);
default:
return __cmpxchg_local_generic(ptr, old, new, size);
}
return old;
}
#define cmpxchg_local(ptr, old, new) \
((typeof(*(ptr)))__cmpxchg_local((ptr), (unsigned long)(old), \
(unsigned long)(new), \
sizeof(*(ptr))))
#define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n))
#endif /* __ASM_AVR32_CMPXCHG_H */
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