[PATCHv3 13/16] pps: capture MONOTONIC_RAW timestamps as well
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From: Alexander Gordeev on 4 Aug 2010 17:20 MONOTONIC_RAW clock timestamps are ideally suited for frequency calculation and also fit well into the original NTP hardpps design. Now phase and frequency can be adjusted separately: the former based on REALTIME clock and the latter based on MONOTONIC_RAW clock. A new function getnstime_raw_and_real is added to timekeeping subsystem to capture both timestamps at the same time and atomically. Signed-off-by: Alexander Gordeev <lasaine(a)lvk.cs.msu.su> --- include/linux/pps_kernel.h | 3 ++- include/linux/time.h | 2 ++ kernel/time/timekeeping.c | 34 ++++++++++++++++++++++++++++++++++ 3 files changed, 38 insertions(+), 1 deletions(-) diff --git a/include/linux/pps_kernel.h b/include/linux/pps_kernel.h index 5af0498..39fc712 100644 --- a/include/linux/pps_kernel.h +++ b/include/linux/pps_kernel.h @@ -48,6 +48,7 @@ struct pps_source_info { }; struct pps_event_time { + struct timespec ts_raw; struct timespec ts_real; }; @@ -111,7 +112,7 @@ static inline void timespec_to_pps_ktime(struct pps_ktime *kt, static inline void pps_get_ts(struct pps_event_time *ts) { - getnstimeofday(&ts->ts_real); + getnstime_raw_and_real(&ts->ts_raw, &ts->ts_real); } #endif /* LINUX_PPS_KERNEL_H */ diff --git a/include/linux/time.h b/include/linux/time.h index ea3559f..1da8a7b 100644 --- a/include/linux/time.h +++ b/include/linux/time.h @@ -143,6 +143,8 @@ extern unsigned int alarm_setitimer(unsigned int seconds); extern int do_getitimer(int which, struct itimerval *value); extern void getnstimeofday(struct timespec *tv); extern void getrawmonotonic(struct timespec *ts); +extern void getnstime_raw_and_real(struct timespec *ts_raw, + struct timespec *ts_real); extern void getboottime(struct timespec *ts); extern void monotonic_to_bootbased(struct timespec *ts); diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index caf8d4d..ef37b14 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -286,6 +286,40 @@ void ktime_get_ts(struct timespec *ts) EXPORT_SYMBOL_GPL(ktime_get_ts); /** + * getnstime_raw_and_real - Returns both the time of day an raw + * monotonic time in a timespec format + * @ts_mono_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 + */ +void getnstime_raw_and_real(struct timespec *ts_raw, struct timespec *ts_real) +{ + unsigned long seq; + s64 nsecs_raw, nsecs_real; + + WARN_ON(timekeeping_suspended); + + do { + seq = read_seqbegin(&xtime_lock); + + *ts_raw = raw_time; + *ts_real = xtime; + + nsecs_raw = timekeeping_get_ns_raw(); + nsecs_real = timekeeping_get_ns(); + + /* If arch requires, add in gettimeoffset() */ + nsecs_real += arch_gettimeoffset(); + + } while (read_seqretry(&xtime_lock, seq)); + + timespec_add_ns(ts_raw, nsecs_raw); + timespec_add_ns(ts_real, nsecs_real); +} +EXPORT_SYMBOL(getnstime_raw_and_real); + +/** * do_gettimeofday - Returns the time of day in a timeval * @tv: pointer to the timeval to be set * -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |