x86: add apic probe for genapic 64bit - fix

intr_remapping_enabled get assigned later, so need to check that
in setup_apic_routing

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Cc: Jack Steiner <steiner@sgi.com>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 6 insertions, 0 deletions

diff --git a/arch/x86/kernel/genapic_64.c b/arch/x86/kernel/genapic_64.c
index b3ba969c50d2..6c9bfc9e1e95 100644
--- a/arch/x86/kernel/genapic_64.c
+++ b/arch/x86/kernel/genapic_64.c
@@ -16,6 +16,7 @@
 #include <linux/ctype.h>
 #include <linux/init.h>
 #include <linux/hardirq.h>
+#include <linux/dmar.h>
 
 #include <asm/smp.h>
 #include <asm/ipi.h>
@@ -42,6 +43,11 @@ static struct genapic *apic_probe[] __initdata = {
  */
 void __init setup_apic_routing(void)
 {
+        if (genapic == &apic_x2apic_phys || genapic == &apic_x2apic_cluster) {
+                if (!intr_remapping_enabled)
+                        genapic = &apic_flat;
+        }
+
         if (genapic == &apic_flat) {
                 if (max_physical_apicid >= 8)
                         genapic = &apic_physflat;