diff --git a/kernel/sys.c b/kernel/sys.c
index 1b33b05..8ae2e63 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -32,6 +32,7 @@
 #include <linux/getcpu.h>
 #include <linux/task_io_accounting_ops.h>
 #include <linux/seccomp.h>
+#include <linux/cpu.h>
 
 #include <linux/compat.h>
 #include <linux/syscalls.h>
@@ -878,6 +879,7 @@ void kernel_power_off(void)
        kernel_shutdown_prepare(SYSTEM_POWER_OFF);
        if (pm_power_off_prepare)
                pm_power_off_prepare();
+       disable_nonboot_cpus();
        sysdev_shutdown();
        printk(KERN_EMERG "Power down.\n");
        machine_power_off();


And here's the fix.

From: Johannes Berg <johannes@sipsolutions.net>
Subject: powerpc: fix shutdown

I tracked down the shutdown regression to CPUs not dying
when being shut down during power-off. This turns out to
be due to the system_state being SYSTEM_POWER_OFF, which
this code doesn't take as a valid state for shutting off
CPUs in.

This has never made sense to me, but when I added hotplug
code to implement hibernate I only "made it work" and did
not question the need to check the system_state. Thomas
Gleixner helped me dig, but the only thing we found is
that it was added with the original commit that added CPU
hotplug support.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Joel Schopp <jschopp@austin.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---
 arch/powerpc/kernel/idle.c |    4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

--- a/arch/powerpc/kernel/idle.c
+++ b/arch/powerpc/kernel/idle.c
@@ -36,9 +36,7 @@
 #ifdef CONFIG_HOTPLUG_CPU
 /* this is used for software suspend, and that shuts down
  * CPUs even while the system is still booting... */
-#define cpu_should_die()	(cpu_is_offline(smp_processor_id()) && \
-				   (system_state == SYSTEM_RUNNING     \
-				 || system_state == SYSTEM_BOOTING))
+#define cpu_should_die()	cpu_is_offline(smp_processor_id())
 #else
 #define cpu_should_die()	0
 #endif