diff --git a/arch/x86_64/kernel/setup.c b/arch/x86_64/kernel/setup.c
index 9435ab7d6fb83131a6efd4b24a9d6cd7621a76fd..5de7eaf5d97cd678025e520cb5d5b2a3041508b5 100644
--- a/arch/x86_64/kernel/setup.c
+++ b/arch/x86_64/kernel/setup.c
@@ -423,6 +423,12 @@ static __init void parse_cmdline_early (char ** cmdline_p)
 		else if(!memcmp(from, "elfcorehdr=", 11))
 			elfcorehdr_addr = memparse(from+11, &from);
 #endif
+
+#ifdef CONFIG_SMP
+		else if (!memcmp(from, "additional_cpus=", 16))
+			setup_additional_cpus(from+16);
+#endif
+
 	next_char:
 		c = *(from++);
 		if (!c)
diff --git a/arch/x86_64/kernel/smpboot.c b/arch/x86_64/kernel/smpboot.c
index 67e4e28f4df8d79d9b97d76b7e2ec0fbf794f5e1..b82eb86e4f5de33b9963b17ddfb8a39be84f351d 100644
--- a/arch/x86_64/kernel/smpboot.c
+++ b/arch/x86_64/kernel/smpboot.c
@@ -1244,7 +1244,7 @@ void __cpu_die(unsigned int cpu)
  	printk(KERN_ERR "CPU %u didn't die...\n", cpu);
 }
 
-static __init int setup_additional_cpus(char *s)
+__init int setup_additional_cpus(char *s)
 {
 	return get_option(&s, &additional_cpus);
 }
diff --git a/include/asm-x86_64/proto.h b/include/asm-x86_64/proto.h
index eca3f2d633dbb67368e57cdd0e550218f1ea4516..8bdcbd0aa03f5845491e6692440bbed2ad36c50b 100644
--- a/include/asm-x86_64/proto.h
+++ b/include/asm-x86_64/proto.h
@@ -134,6 +134,7 @@ extern int force_iommu;
 
 extern int reboot_force;
 extern int notsc_setup(char *);
+extern int setup_additional_cpus(char *);
 
 extern void smp_local_timer_interrupt(struct pt_regs * regs);