time: Remove duplicated code in ktime_get_raw_and_real()

The code in ktime_get_snapshot() is a superset of the code in
ktime_get_raw_and_real() code. Further, ktime_get_raw_and_real() is
called only by the PPS code, pps_get_ts(). Consolidate the
pps_get_ts() code into a single function calling ktime_get_snapshot()
and eliminate ktime_get_raw_and_real(). A side effect of this is that
the raw and real results of pps_get_ts() correspond to exactly the
same clock cycle. Previously these values represented separate reads
of the system clock.

Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: kevin.b.stanton@intel.com
Cc: kevin.j.clarke@intel.com
Cc: hpa@zytor.com
Cc: jeffrey.t.kirsher@intel.com
Cc: netdev@vger.kernel.org
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Christopher S. Hall <christopher.s.hall@intel.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>

diff --git a/include/linux/pps_kernel.h b/include/linux/pps_kernel.h
index 54bf1484d41f0333cc860c84307d23eda76477e5..35ac903956c7c0c282a9b0cfd74004212c8eb10d 100644 (file)
--- a/include/linux/pps_kernel.h
+++ b/include/linux/pps_kernel.h
@@ -111,22 +111,17 @@ static inline void timespec_to_pps_ktime(struct pps_ktime *kt,
        kt->nsec = ts.tv_nsec;
 }
 
-#ifdef CONFIG_NTP_PPS
-
 static inline void pps_get_ts(struct pps_event_time *ts)
 {
-       ktime_get_raw_and_real_ts64(&ts->ts_raw, &ts->ts_real);
-}
+       struct system_time_snapshot snap;
 
-#else /* CONFIG_NTP_PPS */
-
-static inline void pps_get_ts(struct pps_event_time *ts)
-{
-       ktime_get_real_ts64(&ts->ts_real);
+       ktime_get_snapshot(&snap);
+       ts->ts_real = ktime_to_timespec64(snap.real);
+#ifdef CONFIG_NTP_PPS
+       ts->ts_raw = ktime_to_timespec64(snap.raw);
+#endif
 }
 
-#endif /* CONFIG_NTP_PPS */
-
 /* Subtract known time delay from PPS event time(s) */
 static inline void pps_sub_ts(struct pps_event_time *ts, struct timespec64 delta)
 {

diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index 89b4695bd0837d21e6160eeb4c5d21129e414ee9..af19a49d52230e1a373a22bf74fe998d5076ab75 100644 (file)
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -888,6 +888,8 @@ void ktime_get_snapshot(struct system_time_snapshot *systime_snapshot)
        s64 nsec_real;
        cycle_t now;
 
+       WARN_ON_ONCE(timekeeping_suspended);
+
        do {
                seq = read_seqcount_begin(&tk_core.seq);
 
@@ -905,44 +907,6 @@ void ktime_get_snapshot(struct system_time_snapshot *systime_snapshot)
 }
 EXPORT_SYMBOL_GPL(ktime_get_snapshot);
 
-#ifdef CONFIG_NTP_PPS
-
-/**
- * ktime_get_raw_and_real_ts64 - get day and raw monotonic time in timespec format
- * @ts_raw:    pointer to the timespec to be set to raw monotonic time
- * @ts_real:   pointer to the timespec to be set to the time of day
- *
- * This function reads both the time of day and raw monotonic time at the
- * same time atomically and stores the resulting timestamps in timespec
- * format.
- */
-void ktime_get_raw_and_real_ts64(struct timespec64 *ts_raw, struct timespec64 *ts_real)
-{
-       struct timekeeper *tk = &tk_core.timekeeper;
-       unsigned long seq;
-       s64 nsecs_raw, nsecs_real;
-
-       WARN_ON_ONCE(timekeeping_suspended);
-
-       do {
-               seq = read_seqcount_begin(&tk_core.seq);
-
-               *ts_raw = tk->raw_time;
-               ts_real->tv_sec = tk->xtime_sec;
-               ts_real->tv_nsec = 0;
-
-               nsecs_raw  = timekeeping_get_ns(&tk->tkr_raw);
-               nsecs_real = timekeeping_get_ns(&tk->tkr_mono);
-
-       } while (read_seqcount_retry(&tk_core.seq, seq));
-
-       timespec64_add_ns(ts_raw, nsecs_raw);
-       timespec64_add_ns(ts_real, nsecs_real);
-}
-EXPORT_SYMBOL(ktime_get_raw_and_real_ts64);
-
-#endif /* CONFIG_NTP_PPS */
-
 /**
  * do_gettimeofday - Returns the time of day in a timeval
  * @tv:                pointer to the timeval to be set