linux/arch/sh/include/asm/cmpxchg.h
Mark Rutland 8c64175513 locking/atomic: sh: move to ARCH_ATOMIC
We'd like all architectures to convert to ARCH_ATOMIC, as once all
architectures are converted it will be possible to make significant
cleanups to the atomics headers, and this will make it much easier to
generically enable atomic functionality (e.g. debug logic in the
instrumented wrappers).

As a step towards that, this patch migrates sh to ARCH_ATOMIC. The
arch code provides arch_{atomic,atomic64,xchg,cmpxchg}*(), and common
code wraps these with optional instrumentation to provide the regular
functions.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210525140232.53872-30-mark.rutland@arm.com
2021-05-26 13:20:52 +02:00

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 arch_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 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))); \
})
#endif /* __ASM_SH_CMPXCHG_H */