On 15/10/19 12:48, Jianyong Wu wrote:
> Sometimes, we need check current clocksource outside of
> timekeeping area. Add clocksource to system_time_snapshot then
> we can get clocksource as well as system time.
>
> Signed-off-by: Jianyong Wu <jianyong.wu@xxxxxxx>
> Suggested-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
> ---
> include/linux/timekeeping.h | 35 ++++++++++++++++++-----------------
> kernel/time/timekeeping.c | 7 ++++---
> 2 files changed, 22 insertions(+), 20 deletions(-)
>
> diff --git a/include/linux/timekeeping.h b/include/linux/timekeeping.h
> index a8ab0f143ac4..964c14fbbf69 100644
> --- a/include/linux/timekeeping.h
> +++ b/include/linux/timekeeping.h
> @@ -194,23 +194,6 @@ extern bool timekeeping_rtc_skipresume(void);
>
> extern void timekeeping_inject_sleeptime64(const struct timespec64 *delta);
>
> -/*
> - * struct system_time_snapshot - simultaneous raw/real time capture with
> - * counter value
> - * @cycles: Clocksource counter value to produce the system times
> - * @real: Realtime system time
> - * @raw: Monotonic raw system time
> - * @clock_was_set_seq: The sequence number of clock was set events
> - * @cs_was_changed_seq: The sequence number of clocksource change events
> - */
> -struct system_time_snapshot {
> - u64 cycles;
> - ktime_t real;
> - ktime_t raw;
> - unsigned int clock_was_set_seq;
> - u8 cs_was_changed_seq;
> -};
> -
> /*
> * struct system_device_crosststamp - system/device cross-timestamp
> * (syncronized capture)
> @@ -236,6 +219,24 @@ struct system_counterval_t {
> struct clocksource *cs;
> };
>
> +/*
> + * struct system_time_snapshot - simultaneous raw/real time capture with
> + * counter value
> + * @sc: Contains clocksource and clocksource counter value to produce
> + * the system times
> + * @real: Realtime system time
> + * @raw: Monotonic raw system time
> + * @clock_was_set_seq: The sequence number of clock was set events
> + * @cs_was_changed_seq: The sequence number of clocksource change events
> + */
> +struct system_time_snapshot {
> + struct system_counterval_t sc;
> + ktime_t real;
> + ktime_t raw;
> + unsigned int clock_was_set_seq;
> + u8 cs_was_changed_seq;
> +};
> +
> /*
> * Get cross timestamp between system clock and device clock
> */
> diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
> index 44b726bab4bd..66ff089605b3 100644
> --- a/kernel/time/timekeeping.c
> +++ b/kernel/time/timekeeping.c
> @@ -983,7 +983,8 @@ void ktime_get_snapshot(struct system_time_snapshot *systime_snapshot)
> nsec_raw = timekeeping_cycles_to_ns(&tk->tkr_raw, now);
> } while (read_seqcount_retry(&tk_core.seq, seq));
>
> - systime_snapshot->cycles = now;
> + systime_snapshot->sc.cycles = now;
> + systime_snapshot->sc.cs = tk->tkr_mono.clock;
> systime_snapshot->real = ktime_add_ns(base_real, nsec_real);
> systime_snapshot->raw = ktime_add_ns(base_raw, nsec_raw);
> }
> @@ -1189,12 +1190,12 @@ int get_device_system_crosststamp(int (*get_time_fn)
> * clocksource change
> */
> if (!history_begin ||
> - !cycle_between(history_begin->cycles,
> + !cycle_between(history_begin->sc.cycles,
> system_counterval.cycles, cycles) ||
> history_begin->cs_was_changed_seq != cs_was_changed_seq)
> return -EINVAL;
> partial_history_cycles = cycles - system_counterval.cycles;
> - total_history_cycles = cycles - history_begin->cycles;
> + total_history_cycles = cycles - history_begin->sc.cycles;
> discontinuity =
> history_begin->clock_was_set_seq != clock_was_set_seq;
>
>
Reviewed-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
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