[PATCH] x86_64: x86_64 write apic id fix

o Apic id is in most significant 8 bits of APIC_ID register. Current code
  is trying to write apic id to least significant 8 bits. This patch fixes
  it.

o This fix enables booting uni kdump capture kernel on a cpu with non-zero
  apic id.

Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/x86_64/kernel/apic.c

@@ -1066,7 +1066,7 @@ int __init APIC_init_uniprocessor (void)
 	connect_bsp_APIC();
 
 	phys_cpu_present_map = physid_mask_of_physid(boot_cpu_id);
-	apic_write_around(APIC_ID, boot_cpu_id);
+	apic_write_around(APIC_ID, SET_APIC_ID(boot_cpu_id));
 
 	setup_local_APIC();
 

include/asm-x86_64/apicdef.h

@@ -13,6 +13,7 @@
 #define		APIC_ID		0x20
 #define			APIC_ID_MASK		(0xFFu<<24)
 #define			GET_APIC_ID(x)		(((x)>>24)&0xFFu)
+#define			SET_APIC_ID(x)		(((x)<<24))
 #define		APIC_LVR	0x30
 #define			APIC_LVR_MASK		0xFF00FF
 #define			GET_APIC_VERSION(x)	((x)&0xFFu)