x86: add x2apic config

Impact: cleanup

so could deselect x2apic
and INTR_REMAP will select x2apic

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/kernel/apic.c b/arch/x86/kernel/apic.c
index a894eea..004aa1c 100644
--- a/arch/x86/kernel/apic.c
+++ b/arch/x86/kernel/apic.c
@@ -112,11 +112,7 @@
 __setup("apicpmtimer", setup_apicpmtimer);
 #endif
 
-#ifdef CONFIG_X86_64
-#define HAVE_X2APIC
-#endif
-
-#ifdef HAVE_X2APIC
+#ifdef CONFIG_X86_X2APIC
 int x2apic;
 /* x2apic enabled before OS handover */
 static int x2apic_preenabled;
@@ -269,7 +265,7 @@
 struct apic_ops __read_mostly *apic_ops = &xapic_ops;
 EXPORT_SYMBOL_GPL(apic_ops);
 
-#ifdef HAVE_X2APIC
+#ifdef CONFIG_X86_X2APIC
 static void x2apic_wait_icr_idle(void)
 {
 	/* no need to wait for icr idle in x2apic */
@@ -1320,11 +1316,14 @@
 	apic_pm_activate();
 }
 
-#ifdef HAVE_X2APIC
+#ifdef CONFIG_X86_X2APIC
 void check_x2apic(void)
 {
 	int msr, msr2;
 
+	if (!cpu_has_x2apic)
+		return;
+
 	rdmsr(MSR_IA32_APICBASE, msr, msr2);
 
 	if (msr & X2APIC_ENABLE) {
@@ -1338,6 +1337,9 @@
 {
 	int msr, msr2;
 
+	if (!x2apic)
+		return;
+
 	rdmsr(MSR_IA32_APICBASE, msr, msr2);
 	if (!(msr & X2APIC_ENABLE)) {
 		pr_info("Enabling x2apic\n");
@@ -1439,7 +1441,7 @@
 
 	return;
 }
-#endif /* HAVE_X2APIC */
+#endif /* CONFIG_X86_X2APIC */
 
 #ifdef CONFIG_X86_64
 /*
@@ -1570,7 +1572,7 @@
  */
 void __init init_apic_mappings(void)
 {
-#ifdef HAVE_X2APIC
+#ifdef CONFIG_X86_X2APIC
 	if (x2apic) {
 		boot_cpu_physical_apicid = read_apic_id();
 		return;
@@ -1634,9 +1636,7 @@
 	}
 #endif
 
-#ifdef HAVE_X2APIC
 	enable_IR_x2apic();
-#endif
 #ifdef CONFIG_X86_64
 	default_setup_apic_routing();
 #endif
@@ -2021,7 +2021,7 @@
 
 	local_irq_save(flags);
 
-#ifdef HAVE_X2APIC
+#ifdef CONFIG_X86_X2APIC
 	if (x2apic)
 		enable_x2apic();
 	else