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authorYinghai Lu <Yinghai.Lu@Sun.COM>2008-02-23 21:48:42 -0800
committerIngo Molnar <mingo@elte.hu>2008-04-17 17:40:49 +0200
commit322850af8d93735f67b8ebf84bb1350639be3f34 (patch)
tree107a13e6d486d6d5f0791630c8701b100d9cfb92 /arch/x86
parent513ad84bf60d96a6998bca10ed07c3d340449be8 (diff)
downloadlinux-stericsson-322850af8d93735f67b8ebf84bb1350639be3f34.tar.gz
x86: make amd quad core 8 socket system not be clustered_box, #2
quad core 8 socket system will have apic id lifting.the apic id range could be [4, 0x23]. and apic_is_clustered_box will think that need to three clusters and that is large than 2. So it is treated as clustered_box. and will get Marking TSC unstable due to TSCs unsynchronized even the CPUs have X86_FEATURE_CONSTANT_TSC set. this patch will check if the cpu is from AMD. Signed-off-by: Yinghai Lu <yinghai.lu@sun.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/kernel/apic_64.c12
1 files changed, 11 insertions, 1 deletions
diff --git a/arch/x86/kernel/apic_64.c b/arch/x86/kernel/apic_64.c
index d8d03e09dea2..7d8ffdaa0ab3 100644
--- a/arch/x86/kernel/apic_64.c
+++ b/arch/x86/kernel/apic_64.c
@@ -1180,9 +1180,19 @@ __cpuinit int apic_is_clustered_box(void)
{
int i, clusters, zeros;
unsigned id;
- u16 *bios_cpu_apicid = x86_bios_cpu_apicid_early_ptr;
+ u16 *bios_cpu_apicid;
DECLARE_BITMAP(clustermap, NUM_APIC_CLUSTERS);
+ /*
+ * there is not this kind of box with AMD CPU yet.
+ * Some AMD box with quadcore cpu and 8 sockets apicid
+ * will be [4, 0x23] or [8, 0x27] could be thought to
+ * have three apic_clusters. So go out early.
+ */
+ if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
+ return 0;
+
+ bios_cpu_apicid = x86_bios_cpu_apicid_early_ptr;
bitmap_zero(clustermap, NUM_APIC_CLUSTERS);
for (i = 0; i < NR_CPUS; i++) {