i386: fix 4 bit apicid assumption of mach-default
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>
diff --git a/include/asm-x86/mach-default/mach_apicdef.h b/include/asm-x86/mach-default/mach_apicdef.h
index 7bcb350..ae98413 100644
--- a/include/asm-x86/mach-default/mach_apicdef.h
+++ b/include/asm-x86/mach-default/mach_apicdef.h
@@ -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)