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time: Remove duplicated code in ktime_get_raw_and_real()

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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>
This commit is contained in:
Christopher S. Hall 2016-02-22 03:15:21 -08:00 committed by John Stultz
parent 9da0f49c87
commit ba26621e63
2 changed files with 10 additions and 51 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

21
include/linux/pps_kernel.h
View file

@ -111,22 +111,17 @@ static inline void timespec_to_pps_ktime(struct pps_ktime *kt,
kt->nsec = ts.tv_nsec; kt->nsec = ts.tv_nsec;
} }
static inline void pps_get_ts(struct pps_event_time *ts)
{
struct system_time_snapshot snap;
ktime_get_snapshot(&snap);
ts->ts_real = ktime_to_timespec64(snap.real);
#ifdef CONFIG_NTP_PPS #ifdef CONFIG_NTP_PPS
ts->ts_raw = ktime_to_timespec64(snap.raw);
static inline void pps_get_ts(struct pps_event_time *ts) #endif
{
ktime_get_raw_and_real_ts64(&ts->ts_raw, &ts->ts_real);
} }
#else /* CONFIG_NTP_PPS */
static inline void pps_get_ts(struct pps_event_time *ts)
{
ktime_get_real_ts64(&ts->ts_real);
}
#endif /* CONFIG_NTP_PPS */
/* Subtract known time delay from PPS event time(s) */ /* Subtract known time delay from PPS event time(s) */
static inline void pps_sub_ts(struct pps_event_time *ts, struct timespec64 delta) static inline void pps_sub_ts(struct pps_event_time *ts, struct timespec64 delta)
{ {

40
kernel/time/timekeeping.c
View file

@ -888,6 +888,8 @@ void ktime_get_snapshot(struct system_time_snapshot *systime_snapshot)
s64 nsec_real; s64 nsec_real;
cycle_t now; cycle_t now;
WARN_ON_ONCE(timekeeping_suspended);
do { do {
seq = read_seqcount_begin(&tk_core.seq); 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); 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 * do_gettimeofday - Returns the time of day in a timeval
* @tv: pointer to the timeval to be set * @tv: pointer to the timeval to be set