linux-stable/include/asm-generic/cmpxchg-local.h
Mark Rutland 6988631bdf locking/atomic: cmpxchg: make generic a prefix
The asm-generic implementations of cmpxchg_local() and cmpxchg64_local()
use a `_generic` suffix to distinguish themselves from arch code or
wrappers used elsewhere.

Subsequent patches will add ARCH_ATOMIC support to these
implementations, and will distinguish more functions with a `generic`
portion. To align with how ARCH_ATOMIC uses an `arch_` prefix, it would
be helpful to use a `generic_` prefix rather than a `_generic` suffix.

In preparation for this, this patch renames the existing functions to
make `generic` a prefix rather than a suffix. There should be no
functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210525140232.53872-12-mark.rutland@arm.com
2021-05-26 13:20:50 +02:00

68 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 __generic_cmpxchg_local(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 __generic_cmpxchg64_local(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