81 lines
2.4 KiB
C
81 lines
2.4 KiB
C
/* 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);
|
|
/* we only need to support cmpxchg of a u32 on sparc */
|
|
unsigned long __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)
|
|
{
|
|
switch (size) {
|
|
case 4:
|
|
return __cmpxchg_u32((u32 *)ptr, (u32)old, (u32)new_);
|
|
default:
|
|
__cmpxchg_called_with_bad_pointer();
|
|
break;
|
|
}
|
|
return 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(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__ */
|