APIC: enable workaround on AMD Fam10h CPUs

From: Borislav Petkov
Date: Tue Feb 03 2009 - 12:22:32 EST


From: Borislav Petkov <borislav.petkov@xxxxxxx>
Date: Tue, 3 Feb 2009 16:24:22 +0100
Subject: [PATCH] APIC: enable workaround on AMD Fam10h CPUs

Impact: fix to enable APIC for AMD Fam10h on chipsets with a missing/b0rked
ACPI MP table (MADT)

Booting a 32bit kernel on an AMD Fam10h CPU running on chipsets with
missing/b0rked MP table leads to a hang pretty early in the boot process
due to the APIC not being initialized. Fix that by falling back to the
default APIC base address in 32bit code, as it is done in the 64bit
codepath.

Signed-off-by: Borislav Petkov <borislav.petkov@xxxxxxx>
---
arch/x86/kernel/apic.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/arch/x86/kernel/apic.c b/arch/x86/kernel/apic.c
index 4b6df24..115449f 100644
--- a/arch/x86/kernel/apic.c
+++ b/arch/x86/kernel/apic.c
@@ -1436,7 +1436,7 @@ static int __init detect_init_APIC(void)
switch (boot_cpu_data.x86_vendor) {
case X86_VENDOR_AMD:
if ((boot_cpu_data.x86 == 6 && boot_cpu_data.x86_model > 1) ||
- (boot_cpu_data.x86 == 15))
+ (boot_cpu_data.x86 >= 15))
break;
goto no_apic;
case X86_VENDOR_INTEL:
--
1.6.0.4

--
Regards/Gruss,
Boris.

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