xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

x86, x2apic: Allow "nox2apic" to disable x2apic mode setup by BIOS

Browse Source 
Currently "nox2apic" boot parameter was not enabling x2apic mode if the cpu,
kernel are all capable of enabling x2apic mode and the OS handover
happened in xapic mode.

However If the bios enabled x2apic prior to OS handover, using "nox2apic"
boot parameter had no effect.

If the boot cpu's apicid is < 255, enable "nox2apic" boot parameter to
disable the x2apic mode setup by the bios. This will enable the kernel to
fallback to xapic mode and bringup only the cpu's which has apic-id < 255.

-v2: fix patch error and two compiling warning
	make disable_x2apic to be __init

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Link: http://lkml.kernel.org/r/CAE9FiQUeB-3uxJAMiHsz=uPWoFv5Hg1pVepz7aU6YtqOxMC-=Q@mail.gmail.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
This commit is contained in:
Yinghai Lu
2011-12-23 11:01:43 -08:00
committed by H. Peter Anvin
parent fb209bd891
commit a31bc32760
2 changed files with 28 additions and 10 deletions
Download Patch File Download Diff File Expand all files Collapse all files

1
arch/x86/include/asm/apic.h
View File

@@ -216,6 +216,7 @@ static inline void x2apic_force_phys(void)
{
}
#define nox2apic 0
#define x2apic_preenabled 0
#define x2apic_supported() 0
#endif