diff --git a/arch/x86/kernel/apic/apic_flat_64.c b/arch/x86/kernel/apic/apic_flat_64.c
index 5652d31fe108a74206c71af583b79c11d4891777..025921f03eb37d331f72d87513a69b4e595a0a34 100644
--- a/arch/x86/kernel/apic/apic_flat_64.c
+++ b/arch/x86/kernel/apic/apic_flat_64.c
@@ -312,10 +312,18 @@ physflat_cpu_mask_to_apicid_and(const struct cpumask *cpumask,
 	return per_cpu(x86_cpu_to_apicid, cpu);
 }
 
+static int physflat_probe(void)
+{
+	if (apic == &apic_physflat || num_possible_cpus() > 8)
+		return 1;
+
+	return 0;
+}
+
 struct apic apic_physflat =  {
 
 	.name				= "physical flat",
-	.probe				= NULL,
+	.probe				= physflat_probe,
 	.acpi_madt_oem_check		= physflat_acpi_madt_oem_check,
 	.apic_id_registered		= flat_apic_id_registered,
 
diff --git a/arch/x86/kernel/apic/probe_64.c b/arch/x86/kernel/apic/probe_64.c
index d8c4a6feb2862f3a967f7eb4dcc4f503f2dac2f8..39fb42b51f6a9cf6e07ef973ac98b5d098ee21ea 100644
--- a/arch/x86/kernel/apic/probe_64.c
+++ b/arch/x86/kernel/apic/probe_64.c
@@ -54,26 +54,18 @@ static int apicid_phys_pkg_id(int initial_apic_id, int index_msb)
  */
 void __init default_setup_apic_routing(void)
 {
+	int i;
 
 	enable_IR_x2apic();
 
-#ifdef CONFIG_X86_X2APIC
-	if (x2apic_mode
-#ifdef CONFIG_X86_UV
-		       && apic != &apic_x2apic_uv_x
-#endif
-		       ) {
-		if (x2apic_phys)
-			apic = &apic_x2apic_phys;
-		else
-			apic = &apic_x2apic_cluster;
+	for (i = 0; apic_probe[i]; ++i) {
+		if (apic_probe[i]->probe()) {
+			apic = apic_probe[i];
+			break;
+		}
 	}
-#endif
-
-	if (apic == &apic_flat && num_possible_cpus() > 8)
-			apic = &apic_physflat;
 
-	printk(KERN_INFO "Setting APIC routing to %s\n", apic->name);
+	printk(KERN_INFO "APIC routing finalized to %s.\n", apic->name);
 
 	if (is_vsmp_box()) {
 		/* need to update phys_pkg_id */
diff --git a/arch/x86/kernel/apic/x2apic_cluster.c b/arch/x86/kernel/apic/x2apic_cluster.c
index 90949bbd566df155e6596c975caa9cff6e2f8a63..2967bab775e55072ddb1a6ca7bf5580e57d7856e 100644
--- a/arch/x86/kernel/apic/x2apic_cluster.c
+++ b/arch/x86/kernel/apic/x2apic_cluster.c
@@ -184,10 +184,15 @@ static void init_x2apic_ldr(void)
 	per_cpu(x86_cpu_to_logical_apicid, cpu) = apic_read(APIC_LDR);
 }
 
+static int x2apic_cluster_probe(void)
+{
+	return x2apic_mode;
+}
+
 struct apic apic_x2apic_cluster = {
 
 	.name				= "cluster x2apic",
-	.probe				= NULL,
+	.probe				= x2apic_cluster_probe,
 	.acpi_madt_oem_check		= x2apic_acpi_madt_oem_check,
 	.apic_id_registered		= x2apic_apic_id_registered,
 
diff --git a/arch/x86/kernel/apic/x2apic_phys.c b/arch/x86/kernel/apic/x2apic_phys.c
index c7e6d6645bf47f44df8d71419d120ad032b82275..8f21771249f635d89daf92afbc2da4d622e7f1e7 100644
--- a/arch/x86/kernel/apic/x2apic_phys.c
+++ b/arch/x86/kernel/apic/x2apic_phys.c
@@ -173,10 +173,18 @@ static void init_x2apic_ldr(void)
 {
 }
 
+static int x2apic_phys_probe(void)
+{
+	if (x2apic_mode && x2apic_phys)
+		return 1;
+
+	return apic == &apic_x2apic_phys;
+}
+
 struct apic apic_x2apic_phys = {
 
 	.name				= "physical x2apic",
-	.probe				= NULL,
+	.probe				= x2apic_phys_probe,
 	.acpi_madt_oem_check		= x2apic_acpi_madt_oem_check,
 	.apic_id_registered		= x2apic_apic_id_registered,
 
diff --git a/arch/x86/kernel/apic/x2apic_uv_x.c b/arch/x86/kernel/apic/x2apic_uv_x.c
index 7acd2d2ac965f9932f39986ab1fe23361c6de90e..6bb80b1c8a7acda8177266518daeefe13df633bd 100644
--- a/arch/x86/kernel/apic/x2apic_uv_x.c
+++ b/arch/x86/kernel/apic/x2apic_uv_x.c
@@ -326,10 +326,15 @@ static void uv_send_IPI_self(int vector)
 	apic_write(APIC_SELF_IPI, vector);
 }
 
+static int uv_probe(void)
+{
+	return apic == &apic_x2apic_uv_x;
+}
+
 struct apic __refdata apic_x2apic_uv_x = {
 
 	.name				= "UV large system",
-	.probe				= NULL,
+	.probe				= uv_probe,
 	.acpi_madt_oem_check		= uv_acpi_madt_oem_check,
 	.apic_id_registered		= uv_apic_id_registered,