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/* SPDX-License-Identifier: GPL-2.0 */
/* 32-bit atomic xchg() and cmpxchg() definitions.
*
* Copyright (C) 1996 David S. Miller (davem@davemloft.net)
* Copyright (C) 2000 Anton Blanchard (anton@linuxcare.com.au)
* Copyright (C) 2007 Kyle McMartin (kyle@parisc-linux.org)
*
* Additions by Keith M Wesolowski (wesolows@foobazco.org) based
* on asm-parisc/atomic.h Copyright (C) 2000 Philipp Rumpf <prumpf@tux.org>.
*/
#ifndef __ARCH_SPARC_CMPXCHG__
#define __ARCH_SPARC_CMPXCHG__
unsigned long __xchg_u32(volatile u32 *m, u32 new);
void __xchg_called_with_bad_pointer(void);
static __always_inline unsigned long __arch_xchg(unsigned long x, __volatile__ void * ptr, int size)
{
switch (size) {
case 4:
return __xchg_u32(ptr, x);
}
__xchg_called_with_bad_pointer();
return x;
}
#define arch_xchg(ptr,x) ({(__typeof__(*(ptr)))__arch_xchg((unsigned long)(x),(ptr),sizeof(*(ptr)));})
/* Emulate cmpxchg() the same way we emulate atomics,
* by hashing the object address and indexing into an array
* of spinlocks to get a bit of performance...
*
* See arch/sparc/lib/atomic32.c for implementation.
*
* Cribbed from <asm-parisc/atomic.h>
*/
/* bug catcher for when unsupported size is used - won't link */
void __cmpxchg_called_with_bad_pointer(void);
u8 __cmpxchg_u8(volatile u8 *m, u8 old, u8 new_);
u16 __cmpxchg_u16(volatile u16 *m, u16 old, u16 new_);
u32 __cmpxchg_u32(volatile u32 *m, u32 old, u32 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)
{
return
size == 1 ? __cmpxchg_u8(ptr, old, new_) :
size == 2 ? __cmpxchg_u16(ptr, old, new_) :
size == 4 ? __cmpxchg_u32(ptr, old, new_) :
(__cmpxchg_called_with_bad_pointer(), old);
}
#define arch_cmpxchg(ptr, o, n) \
({ \
__typeof__(*(ptr)) _o_ = (o); \
__typeof__(*(ptr)) _n_ = (n); \
(__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_, \
(unsigned long)_n_, sizeof(*(ptr))); \
})
u64 __cmpxchg_u64(volatile u64 *ptr, u64 old, u64 new);
#define arch_cmpxchg64(ptr, old, new) __cmpxchg_u64(ptr, old, new)
#include <asm-generic/cmpxchg-local.h>
/*
* cmpxchg_local and cmpxchg64_local are atomic wrt current CPU. Always make
* them available.
*/
#define arch_cmpxchg_local(ptr, o, n) \
((__typeof__(*(ptr)))__generic_cmpxchg_local((ptr), (unsigned long)(o),\
(unsigned long)(n), sizeof(*(ptr))))
#define arch_cmpxchg64_local(ptr, o, n) __generic_cmpxchg64_local((ptr), (o), (n))
#endif /* __ARCH_SPARC_CMPXCHG__ */
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