rtc: Convert rtc_set_ntp_time() to use timespec64

rtc_set_ntp_time() uses timespec which is y2038-unsafe,
so modify to use timespec64 which is y2038-safe, then
replace rtc_time_to_tm() with rtc_time64_to_tm().

Also adjust all its call sites(only NTP uses it) accordingly.

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: Xunlei Pang <pang.xunlei@linaro.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>

drivers/rtc/systohc.c

@@ -20,16 +20,16 @@
  *
  * If temporary failure is indicated the caller should try again 'soon'
  */
-int rtc_set_ntp_time(struct timespec now)
+int rtc_set_ntp_time(struct timespec64 now)
 {
 	struct rtc_device *rtc;
 	struct rtc_time tm;
 	int err = -ENODEV;
 
 	if (now.tv_nsec < (NSEC_PER_SEC >> 1))
-		rtc_time_to_tm(now.tv_sec, &tm);
+		rtc_time64_to_tm(now.tv_sec, &tm);
 	else
-		rtc_time_to_tm(now.tv_sec + 1, &tm);
+		rtc_time64_to_tm(now.tv_sec + 1, &tm);
 
 	rtc = rtc_class_open(CONFIG_RTC_HCTOSYS_DEVICE);
 	if (rtc) {

include/linux/rtc.h

@@ -161,7 +161,7 @@ extern void devm_rtc_device_unregister(struct device *dev,
 extern int rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm);
 extern int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm);
 extern int rtc_set_mmss(struct rtc_device *rtc, unsigned long secs);
-extern int rtc_set_ntp_time(struct timespec now);
+extern int rtc_set_ntp_time(struct timespec64 now);
 int __rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm);
 extern int rtc_read_alarm(struct rtc_device *rtc,
 			struct rtc_wkalrm *alrm);

kernel/time/ntp.c

@@ -488,13 +488,13 @@ static void sync_cmos_clock(struct work_struct *work)
 
 	getnstimeofday64(&now);
 	if (abs(now.tv_nsec - (NSEC_PER_SEC / 2)) <= tick_nsec * 5) {
-		struct timespec adjust = timespec64_to_timespec(now);
+		struct timespec64 adjust = now;
 
 		fail = -ENODEV;
 		if (persistent_clock_is_local)
 			adjust.tv_sec -= (sys_tz.tz_minuteswest * 60);
 #ifdef CONFIG_GENERIC_CMOS_UPDATE
-		fail = update_persistent_clock(adjust);
+		fail = update_persistent_clock(timespec64_to_timespec(adjust));
 #endif
 #ifdef CONFIG_RTC_SYSTOHC
 		if (fail == -ENODEV)