ppc: fix Power warnings

Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
diff --git a/arch/powerpc/platforms/pseries/hotplug-cpu.c b/arch/powerpc/platforms/pseries/hotplug-cpu.c
index 64c97d8..8de539a 100644
--- a/arch/powerpc/platforms/pseries/hotplug-cpu.c
+++ b/arch/powerpc/platforms/pseries/hotplug-cpu.c
@@ -137,6 +137,8 @@
 		if (get_preferred_offline_state(cpu) == CPU_STATE_ONLINE) {
 			unregister_slb_shadow(hwcpu);
 
+			__hard_irq_disable();
+
 			/*
 			 * Call to start_secondary_resume() will not return.
 			 * Kernel stack will be reset and start_secondary()