69 lines
1.4 KiB
C
69 lines
1.4 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
#ifndef __ASM_GENERIC_CMPXCHG_LOCAL_H
|
|
#define __ASM_GENERIC_CMPXCHG_LOCAL_H
|
|
|
|
#include <linux/types.h>
|
|
#include <linux/irqflags.h>
|
|
|
|
extern unsigned long wrong_size_cmpxchg(volatile void *ptr)
|
|
__noreturn;
|
|
|
|
/*
|
|
* Generic version of __cmpxchg_local (disables interrupts). Takes an unsigned
|
|
* long parameter, supporting various types of architectures.
|
|
*/
|
|
static inline unsigned long __cmpxchg_local_generic(volatile void *ptr,
|
|
unsigned long old, unsigned long new, int size)
|
|
{
|
|
unsigned long flags, prev;
|
|
|
|
/*
|
|
* Sanity checking, compile-time.
|
|
*/
|
|
if (size == 8 && sizeof(unsigned long) != 8)
|
|
wrong_size_cmpxchg(ptr);
|
|
|
|
raw_local_irq_save(flags);
|
|
switch (size) {
|
|
case 1: prev = *(u8 *)ptr;
|
|
if (prev == old)
|
|
*(u8 *)ptr = (u8)new;
|
|
break;
|
|
case 2: prev = *(u16 *)ptr;
|
|
if (prev == old)
|
|
*(u16 *)ptr = (u16)new;
|
|
break;
|
|
case 4: prev = *(u32 *)ptr;
|
|
if (prev == old)
|
|
*(u32 *)ptr = (u32)new;
|
|
break;
|
|
case 8: prev = *(u64 *)ptr;
|
|
if (prev == old)
|
|
*(u64 *)ptr = (u64)new;
|
|
break;
|
|
default:
|
|
wrong_size_cmpxchg(ptr);
|
|
}
|
|
raw_local_irq_restore(flags);
|
|
return prev;
|
|
}
|
|
|
|
/*
|
|
* Generic version of __cmpxchg64_local. Takes an u64 parameter.
|
|
*/
|
|
static inline u64 __cmpxchg64_local_generic(volatile void *ptr,
|
|
u64 old, u64 new)
|
|
{
|
|
u64 prev;
|
|
unsigned long flags;
|
|
|
|
raw_local_irq_save(flags);
|
|
prev = *(u64 *)ptr;
|
|
if (prev == old)
|
|
*(u64 *)ptr = new;
|
|
raw_local_irq_restore(flags);
|
|
return prev;
|
|
}
|
|
|
|
#endif
|