1 files changed, 27 insertions, 0 deletions

diff --git a/kernel/smp.c b/kernel/smp.c
index 2f8b10ecf759..d0ae5b24875e 100644
--- a/kernel/smp.c
+++ b/kernel/smp.c
@@ -13,6 +13,8 @@
 #include <linux/smp.h>
 #include <linux/cpu.h>
 
+#include "smpboot.h"
+
 #ifdef CONFIG_USE_GENERIC_SMP_HELPERS
 static struct {
         struct list_head        queue;
@@ -669,6 +671,8 @@ void __init smp_init(void)
 {
         unsigned int cpu;
 
+        idle_threads_init();
+
         /* FIXME: This should be done in userspace --RR */
         for_each_present_cpu(cpu) {
                 if (num_online_cpus() >= setup_max_cpus)
@@ -791,3 +795,26 @@ void on_each_cpu_cond(bool (*cond_func)(int cpu, void *info),
         }
 }
 EXPORT_SYMBOL(on_each_cpu_cond);
+
+static void do_nothing(void *unused)
+{
+}
+
+/**
+ * kick_all_cpus_sync - Force all cpus out of idle
+ *
+ * Used to synchronize the update of pm_idle function pointer. It's
+ * called after the pointer is updated and returns after the dummy
+ * callback function has been executed on all cpus. The execution of
+ * the function can only happen on the remote cpus after they have
+ * left the idle function which had been called via pm_idle function
+ * pointer. So it's guaranteed that nothing uses the previous pointer
+ * anymore.
+ */
+void kick_all_cpus_sync(void)
+{
+        /* Make sure the change is visible before we kick the cpus */
+        smp_mb();
+        smp_call_function(do_nothing, NULL, 1);
+}
+EXPORT_SYMBOL_GPL(kick_all_cpus_sync);