ntp/pps: use timespec64 for hardpps()

There is only one user of the hardpps function in the kernel, so
it makes sense to atomically change it over to using 64-bit
timestamps for y2038 safety. In the hardpps implementation,
we also need to change the pps_normtime structure, which is
similar to struct timespec and also requires a 64-bit
seconds portion.

This introduces two temporary variables in pps_kc_event() to
do the conversion, they will be removed again in the next step,
which seemed preferable to having a larger patch changing it
all at the same time.

Acked-by: Richard Cochran <[e-mail]>
Acked-by: David S. Miller <[e-mail]>
Reviewed-by: Thomas Gleixner <[e-mail]>
Signed-off-by: Arnd Bergmann <[e-mail]>
Signed-off-by: John Stultz <[e-mail]>

drivers/pps/kc.c

···
 		int event)
 {
 	unsigned long flags;
+	struct timespec64 real = timespec_to_timespec64(ts->ts_real);
+	struct timespec64 raw = timespec_to_timespec64(ts->ts_raw);
 
 	/* Pass some events to kernel consumer if activated */
 	spin_lock_irqsave(&pps_kc_hardpps_lock, flags);
 	if (pps == pps_kc_hardpps_dev && event & pps_kc_hardpps_mode)
-		hardpps(&ts->ts_real, &ts->ts_raw);
+		hardpps(&real, &raw);
 	spin_unlock_irqrestore(&pps_kc_hardpps_lock, flags);
 }

include/linux/timex.h

···
 #define NTP_INTERVAL_LENGTH (NSEC_PER_SEC/NTP_INTERVAL_FREQ)
 
 extern int do_adjtimex(struct timex *);
-extern void hardpps(const struct timespec *, const struct timespec *);
+extern void hardpps(const struct timespec64 *, const struct timespec64 *);
 
 int read_current_timer(unsigned long *timer_val);
 void ntp_notify_cmos_timer(void);

kernel/time/ntp.c

···
 static int pps_valid;		/* signal watchdog counter */
 static long pps_tf[3];		/* phase median filter */
 static long pps_jitter;		/* current jitter (ns) */
-static struct timespec pps_fbase; /* beginning of the last freq interval */
+static struct timespec64 pps_fbase; /* beginning of the last freq interval */
 static int pps_shift;		/* current interval duration (s) (shift) */
 static int pps_intcnt;		/* interval counter */
 static s64 pps_freq;		/* frequency offset (scaled ns/s) */
···
  * pps_normtime.nsec has a range of ( -NSEC_PER_SEC / 2, NSEC_PER_SEC / 2 ]
  * while timespec.tv_nsec has a range of [0, NSEC_PER_SEC) */
 struct pps_normtime {
-	__kernel_time_t	sec;	/* seconds */
+	s64		sec;	/* seconds */
 	long		nsec;	/* nanoseconds */
 };
 
 /* normalize the timestamp so that nsec is in the
    ( -NSEC_PER_SEC / 2, NSEC_PER_SEC / 2 ] interval */
-static inline struct pps_normtime pps_normalize_ts(struct timespec ts)
+static inline struct pps_normtime pps_normalize_ts(struct timespec64 ts)
 {
 	struct pps_normtime norm = {
 		.sec = ts.tv_sec,
···
 		pps_errcnt++;
 		pps_dec_freq_interval();
 		printk_deferred(KERN_ERR
-			"hardpps: PPSERROR: interval too long - %ld s\n",
+			"hardpps: PPSERROR: interval too long - %lld s\n",
 			freq_norm.sec);
 		return 0;
 	}
···
  * This code is based on David Mills's reference nanokernel
  * implementation. It was mostly rewritten but keeps the same idea.
  */
-void __hardpps(const struct timespec *phase_ts, const struct timespec *raw_ts)
+void __hardpps(const struct timespec64 *phase_ts, const struct timespec64 *raw_ts)
 {
 	struct pps_normtime pts_norm, freq_norm;
 
···
 	}
 
 	/* ok, now we have a base for frequency calculation */
-	freq_norm = pps_normalize_ts(timespec_sub(*raw_ts, pps_fbase));
+	freq_norm = pps_normalize_ts(timespec64_sub(*raw_ts, pps_fbase));
 
 	/* check that the signal is in the range
 	 * [1s - MAXFREQ us, 1s + MAXFREQ us], otherwise reject it */

kernel/time/ntp_internal.h

···
 extern int second_overflow(unsigned long secs);
 extern int ntp_validate_timex(struct timex *);
 extern int __do_adjtimex(struct timex *, struct timespec64 *, s32 *);
-extern void __hardpps(const struct timespec *, const struct timespec *);
+extern void __hardpps(const struct timespec64 *, const struct timespec64 *);
 #endif /* _LINUX_NTP_INTERNAL_H */

kernel/time/timekeeping.c

···
 /**
  * hardpps() - Accessor function to NTP __hardpps function
  */
-void hardpps(const struct timespec *phase_ts, const struct timespec *raw_ts)
+void hardpps(const struct timespec64 *phase_ts, const struct timespec64 *raw_ts)
 {
 	unsigned long flags;