Minki/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2024-11-05 03:21:32 +00:00
Code Issues Packages Projects Releases Wiki Activity

x86: move cmpxchg fallbacks to a generic place

Browse Source 
arch/x86/kernel/cpu/intel.c defines a few fallback functions
(cmpxchg_*()) that are used when the CPU doesn't support cmpxchg
and/or cmpxchg64 natively. However, while defined in an Intel-specific
file, these functions are also used for CPUs from other vendors when
they don't support cmpxchg and/or cmpxchg64. This breaks the
compilation when support for Intel CPUs is disabled.

This patch moves these functions to a new
arch/x86/kernel/cpu/cmpxchg.c file, unconditionally compiled when
X86_32 is enabled.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: michael@free-electrons.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Thomas Petazzoni 2008-08-18 12:33:21 +02:00 committed by Ingo Molnar
parent 8bfcb3960f
commit 774400a3ba
3 changed files with 73 additions and 65 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
arch/x86/kernel/cpu/Makefile
View File

@ -5,7 +5,7 @@
obj-y := intel_cacheinfo.o addon_cpuid_features.o
obj-y += proc.o feature_names.o
obj-$(CONFIG_X86_32) += common.o bugs.o
obj-$(CONFIG_X86_32) += common.o bugs.o cmpxchg.o
obj-$(CONFIG_X86_64) += common_64.o bugs_64.o
obj-$(CONFIG_X86_32) += amd.o
obj-$(CONFIG_X86_64) += amd_64.o

72
arch/x86/kernel/cpu/cmpxchg.c Normal file
View File

@ -0,0 +1,72 @@
/*
* cmpxchg*() fallbacks for CPU not supporting these instructions
*/
#include <linux/kernel.h>
#include <linux/smp.h>
#include <linux/module.h>
#ifndef CONFIG_X86_CMPXCHG
unsigned long cmpxchg_386_u8(volatile void *ptr, u8 old, u8 new)
{
u8 prev;
unsigned long flags;
/* Poor man's cmpxchg for 386. Unsuitable for SMP */
local_irq_save(flags);
prev = *(u8 *)ptr;
if (prev == old)
*(u8 *)ptr = new;
local_irq_restore(flags);
return prev;
}
EXPORT_SYMBOL(cmpxchg_386_u8);
unsigned long cmpxchg_386_u16(volatile void *ptr, u16 old, u16 new)
{
u16 prev;
unsigned long flags;
/* Poor man's cmpxchg for 386. Unsuitable for SMP */
local_irq_save(flags);
prev = *(u16 *)ptr;
if (prev == old)
*(u16 *)ptr = new;
local_irq_restore(flags);
return prev;
}
EXPORT_SYMBOL(cmpxchg_386_u16);
unsigned long cmpxchg_386_u32(volatile void *ptr, u32 old, u32 new)
{
u32 prev;
unsigned long flags;
/* Poor man's cmpxchg for 386. Unsuitable for SMP */
local_irq_save(flags);
prev = *(u32 *)ptr;
if (prev == old)
*(u32 *)ptr = new;
local_irq_restore(flags);
return prev;
}
EXPORT_SYMBOL(cmpxchg_386_u32);
#endif
#ifndef CONFIG_X86_CMPXCHG64
unsigned long long cmpxchg_486_u64(volatile void *ptr, u64 old, u64 new)
{
u64 prev;
unsigned long flags;
/* Poor man's cmpxchg8b for 386 and 486. Unsuitable for SMP */
local_irq_save(flags);
prev = *(u64 *)ptr;
if (prev == old)
*(u64 *)ptr = new;
local_irq_restore(flags);
return prev;
}
EXPORT_SYMBOL(cmpxchg_486_u64);
#endif

64
arch/x86/kernel/cpu/intel.c
View File

@ -307,69 +307,5 @@ static struct cpu_dev intel_cpu_dev __cpuinitdata = {
cpu_vendor_dev_register(X86_VENDOR_INTEL, &intel_cpu_dev);
#ifndef CONFIG_X86_CMPXCHG
unsigned long cmpxchg_386_u8(volatile void *ptr, u8 old, u8 new)
{
u8 prev;
unsigned long flags;
/* Poor man's cmpxchg for 386. Unsuitable for SMP */
local_irq_save(flags);
prev = *(u8 *)ptr;
if (prev == old)
*(u8 *)ptr = new;
local_irq_restore(flags);
return prev;
}
EXPORT_SYMBOL(cmpxchg_386_u8);
unsigned long cmpxchg_386_u16(volatile void *ptr, u16 old, u16 new)
{
u16 prev;
unsigned long flags;
/* Poor man's cmpxchg for 386. Unsuitable for SMP */
local_irq_save(flags);
prev = *(u16 *)ptr;
if (prev == old)
*(u16 *)ptr = new;
local_irq_restore(flags);
return prev;
}
EXPORT_SYMBOL(cmpxchg_386_u16);
unsigned long cmpxchg_386_u32(volatile void *ptr, u32 old, u32 new)
{
u32 prev;
unsigned long flags;
/* Poor man's cmpxchg for 386. Unsuitable for SMP */
local_irq_save(flags);
prev = *(u32 *)ptr;
if (prev == old)
*(u32 *)ptr = new;
local_irq_restore(flags);
return prev;
}
EXPORT_SYMBOL(cmpxchg_386_u32);
#endif
#ifndef CONFIG_X86_CMPXCHG64
unsigned long long cmpxchg_486_u64(volatile void *ptr, u64 old, u64 new)
{
u64 prev;
unsigned long flags;
/* Poor man's cmpxchg8b for 386 and 486. Unsuitable for SMP */
local_irq_save(flags);
prev = *(u64 *)ptr;
if (prev == old)
*(u64 *)ptr = new;
local_irq_restore(flags);
return prev;
}
EXPORT_SYMBOL(cmpxchg_486_u64);
#endif
/* arch_initcall(intel_cpu_init); */