time: Implement timespec_add

After accidentally misusing timespec_add_safe, I wanted to make sure
we don't accidently trip over that issue again, so I created a simple
timespec_add() function which we can use to replace the instances
of timespec_add_safe() that don't want the overflow detection.

Signed-off-by: John Stultz <johnstul@us.ibm.com>
LKML-Reference: <1279068988-21864-3-git-send-email-johnstul@us.ibm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 16 insertions, 0 deletions

diff --git a/include/linux/time.h b/include/linux/time.h
index ea3559f0b3f2..9072df83de1f 100644
--- a/include/linux/time.h
+++ b/include/linux/time.h
@@ -76,9 +76,25 @@ extern unsigned long mktime(const unsigned int year, const unsigned int mon,
 			    const unsigned int min, const unsigned int sec);
 
 extern void set_normalized_timespec(struct timespec *ts, time_t sec, s64 nsec);
+
+/*
+ * timespec_add_safe assumes both values are positive and checks
+ * for overflow. It will return TIME_T_MAX if the reutrn would be
+ * smaller then either of the arguments.
+ */
 extern struct timespec timespec_add_safe(const struct timespec lhs,
 					 const struct timespec rhs);
 
+
+static inline struct timespec timespec_add(struct timespec lhs,
+						struct timespec rhs)
+{
+	struct timespec ts_delta;
+	set_normalized_timespec(&ts_delta, lhs.tv_sec + rhs.tv_sec,
+				lhs.tv_nsec + rhs.tv_nsec);
+	return ts_delta;
+}
+
 /*
  * sub = lhs - rhs, in normalized form
  */