x86: add lapic_shutdown for x86_64

Preperatory patch to allow crash_32/64.c merging
Signed-off-by: NHiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

arch/x86/kernel/apic_64.c

@@ -287,6 +287,20 @@ void disable_local_APIC(void)
 	apic_write(APIC_SPIV, value);
 }
 
+void lapic_shutdown(void)
+{
+	unsigned long flags;
+
+	if (!cpu_has_apic)
+		return;
+
+	local_irq_save(flags);
+
+	disable_local_APIC();
+
+	local_irq_restore(flags);
+}
+
 /*
  * This is to verify that we're looking at a real local APIC.
  * Check these against your board if the CPUs aren't getting

include/asm-x86/apic_64.h

@@ -69,6 +69,7 @@ extern void clear_local_APIC (void);
 extern void connect_bsp_APIC (void);
 extern void disconnect_bsp_APIC (int virt_wire_setup);
 extern void disable_local_APIC (void);
+extern void lapic_shutdown (void);
 extern int verify_local_APIC (void);
 extern void cache_APIC_registers (void);
 extern void sync_Arb_IDs (void);