x86: apic - unify verify_local_APIC

Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 6 insertions, 0 deletions

diff --git a/arch/x86/kernel/apic_32.c b/arch/x86/kernel/apic_32.c
index 7783c113be24..7ef7c782a42d 100644
--- a/arch/x86/kernel/apic_32.c
+++ b/arch/x86/kernel/apic_32.c
@@ -878,6 +878,12 @@ int __init verify_local_APIC(void)
          */
         reg0 = apic_read(APIC_ID);
         apic_printk(APIC_DEBUG, "Getting ID: %x\n", reg0);
+        apic_write(APIC_ID, reg0 ^ APIC_ID_MASK);
+        reg1 = apic_read(APIC_ID);
+        apic_printk(APIC_DEBUG, "Getting ID: %x\n", reg1);
+        apic_write(APIC_ID, reg0);
+        if (reg1 != (reg0 ^ APIC_ID_MASK))
+                return 0;
 
         /*
          * The next two are just to see if we have sane values.