[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>
diff --git a/arch/x86_64/kernel/apic.c b/arch/x86_64/kernel/apic.c
index 628aebf..c3239f6 100644
--- a/arch/x86_64/kernel/apic.c
+++ b/arch/x86_64/kernel/apic.c
@@ -1066,7 +1066,7 @@
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();
diff --git a/include/asm-x86_64/apicdef.h b/include/asm-x86_64/apicdef.h
index fb1c99a..decaa2d 100644
--- a/include/asm-x86_64/apicdef.h
+++ b/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)