x86: apic - unify lapic_shutdown

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

1 files changed, 13 insertions, 1 deletions

diff --git a/arch/x86/kernel/apic_64.c b/arch/x86/kernel/apic_64.c
index 4fb903b2fc39..48806546d49f 100644
--- a/arch/x86/kernel/apic_64.c
+++ b/arch/x86/kernel/apic_64.c
@@ -707,6 +707,12 @@ void disable_local_APIC(void)
 #endif
 }
 
+/*
+ * If Linux enabled the LAPIC against the BIOS default disable it down before
+ * re-entering the BIOS on shutdown.  Otherwise the BIOS may get confused and
+ * not power-off.  Additionally clear all LVT entries before disable_local_APIC
+ * for the case where Linux didn't enable the LAPIC.
+ */
 void lapic_shutdown(void)
 {
         unsigned long flags;
@@ -716,7 +722,13 @@ void lapic_shutdown(void)
 
         local_irq_save(flags);
 
-        disable_local_APIC();
+#ifdef CONFIG_X86_32
+        if (!enabled_via_apicbase)
+                clear_local_APIC();
+        else
+#endif
+                disable_local_APIC();
+
 
         local_irq_restore(flags);
 }