time: Expose getboottime64 for in-kernel uses

Adds a timespec64 based getboottime64() implementation
that can be used as we convert internal users of
getboottime away from using timespecs.

Cc: pang.xunlei <pang.xunlei@linaro.org>
Cc: Arnd Bergmann <arnd.bergmann@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>

include/linux/timekeeping.h

@@ -33,6 +33,7 @@ extern time64_t ktime_get_real_seconds(void);
 
 extern int __getnstimeofday64(struct timespec64 *tv);
 extern void getnstimeofday64(struct timespec64 *tv);
+extern void getboottime64(struct timespec64 *ts);
 
 #if BITS_PER_LONG == 64
 /**
@@ -72,6 +73,11 @@ static inline struct timespec get_monotonic_coarse(void)
 {
 	return get_monotonic_coarse64();
 }
+
+static inline void getboottime(struct timespec *ts)
+{
+	return getboottime64(ts);
+}
 #else
 /**
  * Deprecated. Use do_settimeofday64().
@@ -129,9 +135,15 @@ static inline struct timespec get_monotonic_coarse(void)
 {
 	return timespec64_to_timespec(get_monotonic_coarse64());
 }
-#endif
 
-extern void getboottime(struct timespec *ts);
+static inline void getboottime(struct timespec *ts)
+{
+	struct timespec64 ts64;
+
+	getboottime64(&ts64);
+	*ts = timespec64_to_timespec(ts64);
+}
+#endif
 
 #define do_posix_clock_monotonic_gettime(ts) ktime_get_ts(ts)
 #define ktime_get_real_ts64(ts)	getnstimeofday64(ts)

kernel/time/timekeeping.c

@@ -1659,24 +1659,24 @@ void update_wall_time(void)
 }
 
 /**
- * getboottime - Return the real time of system boot.
- * @ts:		pointer to the timespec to be set
+ * getboottime64 - Return the real time of system boot.
+ * @ts:		pointer to the timespec64 to be set
  *
- * Returns the wall-time of boot in a timespec.
+ * Returns the wall-time of boot in a timespec64.
  *
  * This is based on the wall_to_monotonic offset and the total suspend
  * time. Calls to settimeofday will affect the value returned (which
  * basically means that however wrong your real time clock is at boot time,
  * you get the right time here).
  */
-void getboottime(struct timespec *ts)
+void getboottime64(struct timespec64 *ts)
 {
 	struct timekeeper *tk = &tk_core.timekeeper;
 	ktime_t t = ktime_sub(tk->offs_real, tk->offs_boot);
 
-	*ts = ktime_to_timespec(t);
+	*ts = ktime_to_timespec64(t);
 }
-EXPORT_SYMBOL_GPL(getboottime);
+EXPORT_SYMBOL_GPL(getboottime64);
 
 unsigned long get_seconds(void)
 {