linux/arch/sh/include/asm/cmpxchg.h

75 lines
1.8 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __ASM_SH_CMPXCHG_H
#define __ASM_SH_CMPXCHG_H
/*
* Atomic operations that C can't guarantee us. Useful for
* resource counting etc..
*/
#include <linux/compiler.h>
#include <linux/types.h>
#if defined(CONFIG_GUSA_RB)
#include <asm/cmpxchg-grb.h>
#elif defined(CONFIG_CPU_SH4A)
#include <asm/cmpxchg-llsc.h>
#elif defined(CONFIG_CPU_J2) && defined(CONFIG_SMP)
#include <asm/cmpxchg-cas.h>
#else
#include <asm/cmpxchg-irq.h>
#endif
extern void __xchg_called_with_bad_pointer(void);
#define __xchg(ptr, x, size) \
({ \
unsigned long __xchg__res; \
volatile void *__xchg_ptr = (ptr); \
switch (size) { \
case 4: \
__xchg__res = xchg_u32(__xchg_ptr, x); \
break; \
case 2: \
__xchg__res = xchg_u16(__xchg_ptr, x); \
break; \
case 1: \
__xchg__res = xchg_u8(__xchg_ptr, x); \
break; \
default: \
__xchg_called_with_bad_pointer(); \
__xchg__res = x; \
break; \
} \
\
__xchg__res; \
})
#define xchg(ptr,x) \
((__typeof__(*(ptr)))__xchg((ptr),(unsigned long)(x), sizeof(*(ptr))))
/* 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);
}
__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))); \
})
#endif /* __ASM_SH_CMPXCHG_H */