2 files changed, 19 insertions, 1 deletions

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index fc8351f374fd..adaca6fa927d 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1438,6 +1438,24 @@ config HOTPLUG_CPU
             automatically on SMP systems. )
           Say N if you want to disable CPU hotplug.
 
+config HOTPLUG_RESTRICT_TO_BOOTUP_CPUS
+        def_bool n
+        prompt "Restrict CPU hotplugging to processors found during boot" if HOTPLUG_CPU
+        ---help---
+          Say no here to use the default, which allows as many CPUs as are marked
+          "disabled" by ACPI or MPTABLES to be hotplugged after bootup.
+
+          Say yes if you do not want to allow CPUs to be added after booting, for
+          example if you only need CPU hotplugging enabled for suspend/resume.
+
+          If CPU_HOTPLUG is enabled this value may be overridden at boot time
+          with the "additional_cpus" kernel parameter.
+
+config HOTPLUG_ADDITIONAL_CPUS
+        int
+        default  0 if !HOTPLUG_CPU || HOTPLUG_RESTRICT_TO_BOOTUP_CPUS
+        default -1
+
 config COMPAT_VDSO
         def_bool y
         prompt "Compat VDSO support"
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 23913785c262..857a88bb9195 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -1261,7 +1261,7 @@ void __init native_smp_cpus_done(unsigned int max_cpus)
         check_nmi_watchdog();
 }
 
-static int additional_cpus __initdata = -1;
+static int additional_cpus __initdata = CONFIG_HOTPLUG_ADDITIONAL_CPUS;
 
 /*
  * cpu_possible_map should be static, it cannot change as cpu's