1 files changed, 36 insertions, 5 deletions

diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index e14c839e9faa..77e930d08e09 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -284,6 +284,33 @@ void ktime_get_ts(struct timespec *ts)
 }
 EXPORT_SYMBOL_GPL(ktime_get_ts);
 
+
+/**
+ * getnsboottime - get the bootbased clock in nsec format
+ *
+ * The function calculates the bootbased clock from the realtime
+ * clock and the wall_to_monotonic offset and stores the result
+ * in normalized timespec format in the variable pointed to by @ts.
+ */
+s64 getnsboottime(void)
+{
+	unsigned int seq;
+	s64 secs, nsecs;
+
+	WARN_ON(timekeeping_suspended);
+
+	do {
+		seq = read_seqbegin(&xtime_lock);
+		secs = xtime.tv_sec + wall_to_monotonic.tv_sec;
+		secs += total_sleep_time.tv_sec;
+		nsecs = xtime.tv_nsec + wall_to_monotonic.tv_nsec;
+		nsecs += total_sleep_time.tv_nsec + timekeeping_get_ns();
+
+	} while (read_seqretry(&xtime_lock, seq));
+	return nsecs + (secs * NSEC_PER_SEC);
+}
+EXPORT_SYMBOL_GPL(getnsboottime);
+
 /**
  * do_gettimeofday - Returns the time of day in a timeval
  * @tv:		pointer to the timeval to be set
@@ -690,6 +717,7 @@ static void timekeeping_adjust(s64 offset)
 static cycle_t logarithmic_accumulation(cycle_t offset, int shift)
 {
 	u64 nsecps = (u64)NSEC_PER_SEC << timekeeper.shift;
+	u64 raw_nsecs;
 
 	/* If the offset is smaller then a shifted interval, do nothing */
 	if (offset < timekeeper.cycle_interval<<shift)
@@ -706,12 +734,15 @@ static cycle_t logarithmic_accumulation(cycle_t offset, int shift)
 		second_overflow();
 	}
 
-	/* Accumulate into raw time */
-	raw_time.tv_nsec += timekeeper.raw_interval << shift;;
-	while (raw_time.tv_nsec >= NSEC_PER_SEC) {
-		raw_time.tv_nsec -= NSEC_PER_SEC;
-		raw_time.tv_sec++;
+	/* Accumulate raw time */
+	raw_nsecs = timekeeper.raw_interval << shift;
+	raw_nsecs += raw_time.tv_nsec;
+	if (raw_nsecs >= NSEC_PER_SEC) {
+		u64 raw_secs = raw_nsecs;
+		raw_nsecs = do_div(raw_secs, NSEC_PER_SEC);
+		raw_time.tv_sec += raw_secs;
 	}
+	raw_time.tv_nsec = raw_nsecs;
 
 	/* Accumulate error between NTP and clock interval */
 	timekeeper.ntp_error += tick_length << shift;