From: Shaohua Li Checking APIC version instead of CPU family to determine XAPIC. Family 6 CPU could have xapic as well. Signed-off-by: Shaohua Li Cc: Dave Jones Cc: "Seth, Rohit" Cc: Andi Kleen Signed-off-by: Andrew Morton --- arch/i386/kernel/io_apic.c | 3 ++- arch/i386/kernel/mpparse.c | 3 ++- 2 files changed, 4 insertions(+), 2 deletions(-) diff -puN arch/i386/kernel/io_apic.c~x86-deterine-xapic-using-apic-version arch/i386/kernel/io_apic.c --- devel/arch/i386/kernel/io_apic.c~x86-deterine-xapic-using-apic-version 2006-03-06 18:28:18.000000000 -0800 +++ devel-akpm/arch/i386/kernel/io_apic.c 2006-03-06 18:28:18.000000000 -0800 @@ -1761,7 +1761,8 @@ static void __init setup_ioapic_ids_from * Don't check I/O APIC IDs for xAPIC systems. They have * no meaning without the serial APIC bus. */ - if (!(boot_cpu_data.x86_vendor == X86_VENDOR_INTEL && boot_cpu_data.x86 < 15)) + if (!(boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) + || APIC_XAPIC(apic_version[boot_cpu_physical_apicid])) return; /* * This is broken; anything with a real cpu count has to diff -puN arch/i386/kernel/mpparse.c~x86-deterine-xapic-using-apic-version arch/i386/kernel/mpparse.c --- devel/arch/i386/kernel/mpparse.c~x86-deterine-xapic-using-apic-version 2006-03-06 18:28:18.000000000 -0800 +++ devel-akpm/arch/i386/kernel/mpparse.c 2006-03-06 18:28:18.000000000 -0800 @@ -937,7 +937,8 @@ void __init mp_register_ioapic ( mp_ioapics[idx].mpc_apicaddr = address; set_fixmap_nocache(FIX_IO_APIC_BASE_0 + idx, address); - if ((boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) && (boot_cpu_data.x86 < 15)) + if ((boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) + && !APIC_XAPIC(apic_version[boot_cpu_physical_apicid])) tmpid = io_apic_get_unique_id(idx, id); else tmpid = id; _