1 files changed, 27 insertions, 2 deletions

diff --git a/arch/x86/kernel/apic/probe_32.c b/arch/x86/kernel/apic/probe_32.c
index 1a6559f6768c..99d2fe016084 100644
--- a/arch/x86/kernel/apic/probe_32.c
+++ b/arch/x86/kernel/apic/probe_32.c
@@ -52,7 +52,32 @@ static int __init print_ipi_mode(void)
 }
 late_initcall(print_ipi_mode);
 
-void default_setup_apic_routing(void)
+void __init default_setup_apic_routing(void)
+{
+        int version = apic_version[boot_cpu_physical_apicid];
+
+        if (num_possible_cpus() > 8) {
+                switch (boot_cpu_data.x86_vendor) {
+                case X86_VENDOR_INTEL:
+                        if (!APIC_XAPIC(version)) {
+                                def_to_bigsmp = 0;
+                                break;
+                        }
+                        /* If P4 and above fall through */
+                case X86_VENDOR_AMD:
+                        def_to_bigsmp = 1;
+                }
+        }
+
+#ifdef CONFIG_X86_BIGSMP
+        generic_bigsmp_probe();
+#endif
+
+        if (apic->setup_apic_routing)
+                apic->setup_apic_routing();
+}
+
+static void setup_apic_flat_routing(void)
 {
 #ifdef CONFIG_X86_IO_APIC
         printk(KERN_INFO
@@ -103,7 +128,7 @@ struct apic apic_default = {
         .init_apic_ldr                  = default_init_apic_ldr,
 
         .ioapic_phys_id_map             = default_ioapic_phys_id_map,
-        .setup_apic_routing             = default_setup_apic_routing,
+        .setup_apic_routing             = setup_apic_flat_routing,
         .multi_timer_check              = NULL,
         .apicid_to_node                 = default_apicid_to_node,
         .cpu_to_logical_apicid          = default_cpu_to_logical_apicid,