x86, mce: support more than 256 CPUs in struct mce

The old struct mce had a limitation to 256 CPUs. But x86 Linux supports
more than that now with x2apic. Add a new field extcpu to report the
extended number.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
diff --git a/arch/x86/include/asm/mce.h b/arch/x86/include/asm/mce.h
index 0a61946..b4a04b6 100644
--- a/arch/x86/include/asm/mce.h
+++ b/arch/x86/include/asm/mce.h
@@ -40,9 +40,9 @@
 	__u64 res2;	/* dito. */
 	__u8  cs;		/* code segment */
 	__u8  bank;	/* machine check bank */
-	__u8  cpu;	/* cpu that raised the error */
+	__u8  cpu;	/* cpu number; obsolete; use extcpu now */
 	__u8  finished;   /* entry is valid */
-	__u32 pad;
+	__u32 extcpu;	/* linux cpu number that detected the error */
 };
 
 /*