diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 8c3fef1..637519a 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -153,6 +153,7 @@
 	unsigned long seq, last_jiffies, next_jiffies, delta_jiffies, flags;
 	struct tick_sched *ts;
 	ktime_t last_update, expires, now, delta;
+	struct clock_event_device *dev = __get_cpu_var(tick_cpu_device).evtdev;
 	int cpu;
 
 	local_irq_save(flags);
@@ -302,11 +303,26 @@
 out:
 	ts->next_jiffies = next_jiffies;
 	ts->last_jiffies = last_jiffies;
+	ts->sleep_length = ktime_sub(dev->next_event, now);
 end:
 	local_irq_restore(flags);
 }
 
 /**
+ * tick_nohz_get_sleep_length - return the length of the current sleep
+ *
+ * Called from power state control code with interrupts disabled
+ */
+ktime_t tick_nohz_get_sleep_length(void)
+{
+	struct tick_sched *ts = &__get_cpu_var(tick_cpu_sched);
+
+	return ts->sleep_length;
+}
+
+EXPORT_SYMBOL_GPL(tick_nohz_get_sleep_length);
+
+/**
  * nohz_restart_sched_tick - restart the idle tick from the idle task
  *
  * Restart the idle tick when the CPU is woken up from idle