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| author | Yinghai Lu <yinghai@kernel.org> | 2011-12-23 11:01:43 -0800 |
|---|---|---|
| committer | H. Peter Anvin <hpa@linux.intel.com> | 2011-12-23 11:01:43 -0800 |
| commit | a31bc32760992a2c68f3d6bf7da9f760c0fd7c41 (patch) | |
| tree | 4a1d5a5944f120d213cfb118f369d3c6d4540a41 /arch/x86/include/asm/apic.h | |
| parent | fb209bd891645bb87b9618b724f0b4928e0df3de (diff) | |
| download | blackbird-op-linux-a31bc32760992a2c68f3d6bf7da9f760c0fd7c41.tar.gz blackbird-op-linux-a31bc32760992a2c68f3d6bf7da9f760c0fd7c41.zip | |
x86, x2apic: Allow "nox2apic" to disable x2apic mode setup by BIOS
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>
Diffstat (limited to 'arch/x86/include/asm/apic.h')
| -rw-r--r-- | arch/x86/include/asm/apic.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h index a12d57193fef..3ab9bdd87e79 100644 --- a/arch/x86/include/asm/apic.h +++ b/arch/x86/include/asm/apic.h @@ -216,6 +216,7 @@ static inline void x2apic_force_phys(void) { } +#define nox2apic 0 #define x2apic_preenabled 0 #define x2apic_supported() 0 #endif |
