x86: Detect use of extended APIC ID for AMD CPUs

[safe/jmp/linux-2.6] / arch / x86 / kernel / cpu / amd.c

diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 7e4a459..0802e15 100644 (file)
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -6,6 +6,7 @@
 #include <asm/processor.h>
 #include <asm/apic.h>
 #include <asm/cpu.h>
+#include <asm/pci-direct.h>
 
 #ifdef CONFIG_X86_64
 # include <asm/numa_64.h>
@@ -351,6 +352,15 @@ static void __cpuinit early_init_amd(struct cpuinfo_x86 *c)
                    (c->x86_model == 8 && c->x86_mask >= 8))
                        set_cpu_cap(c, X86_FEATURE_K6_MTRR);
 #endif
+#if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_PCI)
+       /* check CPU config space for extended APIC ID */
+       if (c->x86 >= 0xf) {
+               unsigned int val;
+               val = read_pci_config(0, 24, 0, 0x68);
+               if ((val & ((1 << 17) | (1 << 18))) == ((1 << 17) | (1 << 18)))
+                       set_cpu_cap(c, X86_FEATURE_EXTD_APICID);
+       }
+#endif
 }
 
 static void __cpuinit init_amd(struct cpuinfo_x86 *c)