[patch 16/56] x86: APIC: enable workaround on AMD Fam10h CPUs

Greg KH
2009-02-11T00:33:42Z

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2.6.27-stable review patch. If anyone has any objections, please let us know.
------------------

From: Borislav Petkov <borislav.petkov@amd.com>

commit 858770619debfb9269add63e4ba8b7c6b5538dd1 upstream.

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@amd.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
arch/x86/kernel/apic_32.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/x86/kernel/apic_32.c
+++ b/arch/x86/kernel/apic_32.c
@@ -1115,7 +1115,7 @@ 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: