i386: fix 4 bit apicid assumption of mach-default
authorSiddha, Suresh B <suresh.b.siddha@intel.com>
Wed, 17 Oct 2007 16:04:33 +0000 (18:04 +0200)
committerThomas Gleixner <tglx@inhelltoy.tec.linutronix.de>
Wed, 17 Oct 2007 18:15:24 +0000 (20:15 +0200)
Fix get_apic_id() in mach-default, so that it uses 8 bits incase of
xAPIC case and 4 bits for legacy APIC case.

This fixes the i386 kernel assumption that apic id is less than 16 for
xAPIC platforms with 8 cpus or less and makes the kernel boot on such
platforms.

[ tglx: arch/x86 adaptation ]

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Andi Kleen <ak@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
include/asm-x86/mach-default/mach_apicdef.h

index 7bcb350..ae98413 100644 (file)
@@ -1,11 +1,17 @@
 #ifndef __ASM_MACH_APICDEF_H
 #define __ASM_MACH_APICDEF_H
 
+#include <asm/apic.h>
+
 #define                APIC_ID_MASK            (0xF<<24)
 
 static inline unsigned get_apic_id(unsigned long x) 
 { 
-       return (((x)>>24)&0xF);
+       unsigned int ver = GET_APIC_VERSION(apic_read(APIC_LVR));
+       if (APIC_XAPIC(ver))
+               return (((x)>>24)&0xFF);
+       else
+               return (((x)>>24)&0xF);
 } 
 
 #define                GET_APIC_ID(x)  get_apic_id(x)