xen: avoid crash in disable_hotplug_cpu

[linux-2.6-microblaze.git] / drivers / xen / cpu_hotplug.c

diff --git a/drivers/xen/cpu_hotplug.c b/drivers/xen/cpu_hotplug.c
index d4265c8..b1357aa 100644 (file)
--- a/drivers/xen/cpu_hotplug.c
+++ b/drivers/xen/cpu_hotplug.c
@@ -19,15 +19,16 @@ static void enable_hotplug_cpu(int cpu)
 
 static void disable_hotplug_cpu(int cpu)
 {
-       if (cpu_online(cpu)) {
-               lock_device_hotplug();
+       if (!cpu_is_hotpluggable(cpu))
+               return;
+       lock_device_hotplug();
+       if (cpu_online(cpu))
                device_offline(get_cpu_device(cpu));
-               unlock_device_hotplug();
-       }
-       if (cpu_present(cpu))
+       if (!cpu_online(cpu) && cpu_present(cpu)) {
                xen_arch_unregister_cpu(cpu);
-
-       set_cpu_present(cpu, false);
+               set_cpu_present(cpu, false);
+       }
+       unlock_device_hotplug();
 }
 
 static int vcpu_online(unsigned int cpu)