time: Introduce timespec64_to_jiffies()/jiffies_to_timespec64()

The conversion between struct timespec and jiffies is not year 2038
safe on 32bit systems. Introduce timespec64_to_jiffies() and
jiffies_to_timespec64() functions which use struct timespec64 to
make it ready for 2038 issue.

Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>

include/linux/jiffies.h

@@ -416,9 +416,25 @@ static inline unsigned long usecs_to_jiffies(const unsigned int u)
 	}
 }
 
-extern unsigned long timespec_to_jiffies(const struct timespec *value);
-extern void jiffies_to_timespec(const unsigned long jiffies,
-				struct timespec *value);
+extern unsigned long timespec64_to_jiffies(const struct timespec64 *value);
+extern void jiffies_to_timespec64(const unsigned long jiffies,
+				  struct timespec64 *value);
+static inline unsigned long timespec_to_jiffies(const struct timespec *value)
+{
+	struct timespec64 ts = timespec_to_timespec64(*value);
+
+	return timespec64_to_jiffies(&ts);
+}
+
+static inline void jiffies_to_timespec(const unsigned long jiffies,
+				       struct timespec *value)
+{
+	struct timespec64 ts;
+
+	jiffies_to_timespec64(jiffies, &ts);
+	*value = timespec64_to_timespec(ts);
+}
+
 extern unsigned long timeval_to_jiffies(const struct timeval *value);
 extern void jiffies_to_timeval(const unsigned long jiffies,
 			       struct timeval *value);

kernel/time/time.c

@@ -540,30 +540,35 @@ EXPORT_SYMBOL(__usecs_to_jiffies);
  * value to a scaled second value.
  */
 static unsigned long
-__timespec_to_jiffies(unsigned long sec, long nsec)
+__timespec64_to_jiffies(u64 sec, long nsec)
 {
 	nsec = nsec + TICK_NSEC - 1;
 
 	if (sec >= MAX_SEC_IN_JIFFIES){
 		sec = MAX_SEC_IN_JIFFIES;
 		nsec = 0;
 	}
-	return (((u64)sec * SEC_CONVERSION) +
+	return ((sec * SEC_CONVERSION) +
 		(((u64)nsec * NSEC_CONVERSION) >>
 		 (NSEC_JIFFIE_SC - SEC_JIFFIE_SC))) >> SEC_JIFFIE_SC;
 
 }
 
-unsigned long
-timespec_to_jiffies(const struct timespec *value)
+static unsigned long
+__timespec_to_jiffies(unsigned long sec, long nsec)
 {
-	return __timespec_to_jiffies(value->tv_sec, value->tv_nsec);
+	return __timespec64_to_jiffies((u64)sec, nsec);
 }
 
-EXPORT_SYMBOL(timespec_to_jiffies);
+unsigned long
+timespec64_to_jiffies(const struct timespec64 *value)
+{
+	return __timespec64_to_jiffies(value->tv_sec, value->tv_nsec);
+}
+EXPORT_SYMBOL(timespec64_to_jiffies);
 
 void
-jiffies_to_timespec(const unsigned long jiffies, struct timespec *value)
+jiffies_to_timespec64(const unsigned long jiffies, struct timespec64 *value)
 {
 	/*
 	 * Convert jiffies to nanoseconds and separate with
@@ -574,7 +579,7 @@ jiffies_to_timespec(const unsigned long jiffies, struct timespec *value)
 				    NSEC_PER_SEC, &rem);
 	value->tv_nsec = rem;
 }
-EXPORT_SYMBOL(jiffies_to_timespec);
+EXPORT_SYMBOL(jiffies_to_timespec64);
 
 /*
  * We could use a similar algorithm to timespec_to_jiffies (with a