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>

3 files changed, 8 insertions, 2 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;
diff --git a/arch/x86/kernel/genx2apic_cluster.c b/arch/x86/kernel/genx2apic_cluster.c
index ef3f3182d50a..fed9f68efd66 100644
--- a/arch/x86/kernel/genx2apic_cluster.c
+++ b/arch/x86/kernel/genx2apic_cluster.c
@@ -14,7 +14,7 @@ DEFINE_PER_CPU(u32, x86_cpu_to_logical_apicid);
 
 static int __init x2apic_acpi_madt_oem_check(char *oem_id, char *oem_table_id)
 {
-        if (cpu_has_x2apic && intr_remapping_enabled)
+        if (cpu_has_x2apic)
                 return 1;
 
         return 0;
diff --git a/arch/x86/kernel/genx2apic_phys.c b/arch/x86/kernel/genx2apic_phys.c
index 3229c68aedd4..958d537b4cc9 100644
--- a/arch/x86/kernel/genx2apic_phys.c
+++ b/arch/x86/kernel/genx2apic_phys.c
@@ -21,7 +21,7 @@ early_param("x2apic_phys", set_x2apic_phys_mode);
 
 static int __init x2apic_acpi_madt_oem_check(char *oem_id, char *oem_table_id)
 {
-        if (cpu_has_x2apic && intr_remapping_enabled && x2apic_phys)
+        if (cpu_has_x2apic && x2apic_phys)
                 return 1;
 
         return 0;