x86, x2apic: fix clear_local_APIC() in the presence of x2apic

Impact: cleanup, paranoia

We were not clearing the local APIC in clear_local_APIC() in the
presence of x2apic. Fix it.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

arch/x86/include/asm/apic.h

@@ -184,6 +184,9 @@ static inline int x2apic_enabled(void)
 {
 	return 0;
 }
+
+#define	x2apic	0
+
 #endif
 
 extern int get_physical_broadcast(void);

arch/x86/include/asm/irq_remapping.h

 #ifndef _ASM_X86_IRQ_REMAPPING_H
 #define _ASM_X86_IRQ_REMAPPING_H
 
-extern int x2apic;
-
 #define IRTE_DEST(dest) ((x2apic) ? dest : dest << 8)
 
 #endif	/* _ASM_X86_IRQ_REMAPPING_H */

arch/x86/kernel/apic/apic.c

@@ -809,7 +809,7 @@ void clear_local_APIC(void)
 	u32 v;
 
 	/* APIC hasn't been mapped yet */
-	if (!apic_phys)
+	if (!x2apic && !apic_phys)
 		return;
 
 	maxlvt = lapic_get_maxlvt();
@@ -1523,12 +1523,10 @@ void __init early_init_lapic_mapping(void)
  */
 void __init init_apic_mappings(void)
 {
-#ifdef CONFIG_X86_X2APIC
 	if (x2apic) {
 		boot_cpu_physical_apicid = read_apic_id();
 		return;
 	}
-#endif
 
 	/*
 	 * If no local APIC can be found then set up a fake all
@@ -1972,12 +1970,9 @@ static int lapic_resume(struct sys_device *dev)
 
 	local_irq_save(flags);
 
-#ifdef CONFIG_X86_X2APIC
 	if (x2apic)
 		enable_x2apic();
-	else
-#endif
-	{
+	else {
 		/*
 		 * Make sure the APICBASE points to the right address
 		 *