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/*
* forked from parisc asm/atomic.h which was:
* Copyright (C) 2000 Philipp Rumpf <prumpf@tux.org>
* Copyright (C) 2006 Kyle McMartin <kyle@parisc-linux.org>
*/
#ifndef _ASM_PARISC_CMPXCHG_H_
#define _ASM_PARISC_CMPXCHG_H_
/* This should get optimized out since it's never called.
** Or get a link error if xchg is used "wrong".
*/
extern void __xchg_called_with_bad_pointer(void);
/* __xchg32/64 defined in arch/parisc/lib/bitops.c */
extern unsigned long __xchg8(char, char *);
extern unsigned long __xchg32(int, int *);
#ifdef CONFIG_64BIT
extern unsigned long __xchg64(unsigned long, unsigned long *);
#endif
/* optimizer better get rid of switch since size is a constant */
static inline unsigned long
__xchg(unsigned long x, __volatile__ void *ptr, int size)
{
switch (size) {
#ifdef CONFIG_64BIT
case 8: return __xchg64(x, (unsigned long *) ptr);
#endif
case 4: return __xchg32((int) x, (int *) ptr);
case 1: return __xchg8((char) x, (char *) ptr);
}
__xchg_called_with_bad_pointer();
return x;
}
/*
** REVISIT - Abandoned use of LDCW in xchg() for now:
** o need to test sizeof(*ptr) to avoid clearing adjacent bytes
** o and while we are at it, could CONFIG_64BIT code use LDCD too?
**
** if (__builtin_constant_p(x) && (x == NULL))
** if (((unsigned long)p & 0xf) == 0)
** return __ldcw(p);
*/
#define xchg(ptr, x) \
({ \
__typeof__(*(ptr)) __ret; \
__typeof__(*(ptr)) _x_ = (x); \
__ret = (__typeof__(*(ptr))) \
__xchg((unsigned long)_x_, (ptr), sizeof(*(ptr))); \
__ret; \
})
/* bug catcher for when unsupported size is used - won't link */
extern void __cmpxchg_called_with_bad_pointer(void);
/* __cmpxchg_u32/u64 defined in arch/parisc/lib/bitops.c */
extern unsigned long __cmpxchg_u32(volatile unsigned int *m, unsigned int old,
unsigned int new_);
extern unsigned long __cmpxchg_u64(volatile unsigned long *ptr,
unsigned long old, unsigned long new_);
/* don't worry...optimizer will get rid of most of this */
static inline unsigned long
__cmpxchg(volatile void *ptr, unsigned long old, unsigned long new_, int size)
{
switch (size) {
#ifdef CONFIG_64BIT
case 8: return __cmpxchg_u64((unsigned long *)ptr, old, new_);
#endif
case 4: return __cmpxchg_u32((unsigned int *)ptr,
(unsigned int)old, (unsigned int)new_);
}
__cmpxchg_called_with_bad_pointer();
return old;
}
#define cmpxchg(ptr, o, n) \
({ \
__typeof__(*(ptr)) _o_ = (o); \
__typeof__(*(ptr)) _n_ = (n); \
(__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_, \
(unsigned long)_n_, 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) {
#ifdef CONFIG_64BIT
case 8: return __cmpxchg_u64((unsigned long *)ptr, old, new_);
#endif
case 4: return __cmpxchg_u32(ptr, old, new_);
default:
return __cmpxchg_local_generic(ptr, old, new_, size);
}
}
/*
* cmpxchg_local and cmpxchg64_local are atomic wrt current CPU. Always make
* them available.
*/
#define cmpxchg_local(ptr, o, n) \
((__typeof__(*(ptr)))__cmpxchg_local((ptr), (unsigned long)(o), \
(unsigned long)(n), sizeof(*(ptr))))
#ifdef CONFIG_64BIT
#define cmpxchg64_local(ptr, o, n) \
({ \
BUILD_BUG_ON(sizeof(*(ptr)) != 8); \
cmpxchg_local((ptr), (o), (n)); \
})
#else
#define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n))
#endif
#endif /* _ASM_PARISC_CMPXCHG_H_ */
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