1 files changed, 20 insertions, 0 deletions

diff --git a/arch/i386/mach-generic/probe.c b/arch/i386/mach-generic/probe.c
index 5497c65a8790..cea5b3ce4b57 100644
--- a/arch/i386/mach-generic/probe.c
+++ b/arch/i386/mach-generic/probe.c
@@ -30,6 +30,25 @@ struct genapic *apic_probe[] __initdata = {
         NULL,
 };
 
+static int cmdline_apic;
+
+void __init generic_bigsmp_probe(void)
+{
+        /*
+         * This routine is used to switch to bigsmp mode when
+         * - There is no apic= option specified by the user
+         * - generic_apic_probe() has choosen apic_default as the sub_arch
+         * - we find more than 8 CPUs in acpi LAPIC listing with xAPIC support
+         */
+
+        if (!cmdline_apic && genapic == &apic_default)
+                if (apic_bigsmp.probe()) {
+                        genapic = &apic_bigsmp;
+                        printk(KERN_INFO "Overriding APIC driver with %s\n",
+                               genapic->name);
+                }
+}
+
 void __init generic_apic_probe(char *command_line) 
 { 
         char *s;
@@ -52,6 +71,7 @@ void __init generic_apic_probe(char *command_line)
                 if (!changed)
                         printk(KERN_ERR "Unknown genapic `%s' specified.\n", s);
                 *p = old;
+                cmdline_apic = changed;
         } 
         for (i = 0; !changed && apic_probe[i]; i++) { 
                 if (apic_probe[i]->probe()) {