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Subject[PATCH] timekeeping: update raw_time with extra arch_gettimeoffset in timekeeping_forward_now
Date
Currently, in timekeeping_forward_now, we just use delta nsecs from
clocksource to update raw_time; however, in getnstime_raw_and_real,
getrawmonotonic64, etc, raw_time has slightly diffrent meaning: it not
only counts the raw monotonic raw time, but also with arch_gettimeoffset,
by using the timekeeping_get_ns_raw helper.

This patch unifies the meaning of raw_time. Also, it cleanups the
timekeeping_get_ns_raw helper, to make timekeeping_get_ns and
timekeeping_forward_now based on it.

Signed-off-by: Jianyu Zhan <nasa4836@gmail.com>
---
kernel/time/timekeeping.c | 52 ++++++++++++++++-------------------------------
1 file changed, 17 insertions(+), 35 deletions(-)

diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index 6a93185..1348c9c 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -191,41 +191,32 @@ u32 (*arch_gettimeoffset)(void) = default_arch_gettimeoffset;
static inline u32 arch_gettimeoffset(void) { return 0; }
#endif

-static inline s64 timekeeping_get_ns(struct tk_read_base *tkr)
+static inline s64 timekeeping_get_ns_raw(struct tk_read_base *tkr,
+ bool update_cycle)
{
+ struct clocksource *clock = tkr->clock;
cycle_t cycle_now, delta;
s64 nsec;

/* read clocksource: */
- cycle_now = tkr->read(tkr->clock);
+ cycle_now = tkr->read(clock);

/* calculate the delta since the last update_wall_time: */
delta = clocksource_delta(cycle_now, tkr->cycle_last, tkr->mask);
+ if (update_cycle)
+ tkr->cycle_last = cycle_now;

- nsec = delta * tkr->mult + tkr->xtime_nsec;
- nsec >>= tkr->shift;
+ /* convert delta to nanoseconds. */
+ nsec = clocksource_cyc2ns(delta, clock->mult, clock->shift);

- /* If arch requires, add in get_arch_timeoffset() */
+ /* If arch requires, add in arch_gettimeoffset() */
return nsec + arch_gettimeoffset();
}

-static inline s64 timekeeping_get_ns_raw(struct timekeeper *tk)
+static inline s64 timekeeping_get_ns(struct tk_read_base *tkr)
{
- struct clocksource *clock = tk->tkr.clock;
- cycle_t cycle_now, delta;
- s64 nsec;
-
- /* read clocksource: */
- cycle_now = tk->tkr.read(clock);
-
- /* calculate the delta since the last update_wall_time: */
- delta = clocksource_delta(cycle_now, tk->tkr.cycle_last, tk->tkr.mask);
-
- /* convert delta to nanoseconds. */
- nsec = clocksource_cyc2ns(delta, clock->mult, clock->shift);
-
- /* If arch requires, add in get_arch_timeoffset() */
- return nsec + arch_gettimeoffset();
+ return timekeeping_get_ns_raw(tkr, false) +
+ (tkr->xtime_nsec >> tkr->shift);
}

/**
@@ -474,22 +465,13 @@ static void timekeeping_update(struct timekeeper *tk, unsigned int action)
*/
static void timekeeping_forward_now(struct timekeeper *tk)
{
- struct clocksource *clock = tk->tkr.clock;
- cycle_t cycle_now, delta;
s64 nsec;

- cycle_now = tk->tkr.read(clock);
- delta = clocksource_delta(cycle_now, tk->tkr.cycle_last, tk->tkr.mask);
- tk->tkr.cycle_last = cycle_now;
-
- tk->tkr.xtime_nsec += delta * tk->tkr.mult;
-
- /* If arch requires, add in get_arch_timeoffset() */
- tk->tkr.xtime_nsec += (u64)arch_gettimeoffset() << tk->tkr.shift;
+ nsec = timekeeping_get_ns_raw(&tk->tkr, true);
+ tk->tkr.xtime_nsec += nsec << tk->tkr.shift;

tk_normalize_xtime(tk);

- nsec = clocksource_cyc2ns(delta, clock->mult, clock->shift);
timespec64_add_ns(&tk->raw_time, nsec);
}

@@ -619,7 +601,7 @@ ktime_t ktime_get_raw(void)
do {
seq = read_seqcount_begin(&tk_core.seq);
base = tk->base_raw;
- nsecs = timekeeping_get_ns_raw(tk);
+ nsecs = timekeeping_get_ns_raw(&tk->tkr, false);

} while (read_seqcount_retry(&tk_core.seq, seq));

@@ -732,7 +714,7 @@ void getnstime_raw_and_real(struct timespec *ts_raw, struct timespec *ts_real)
ts_real->tv_sec = tk->xtime_sec;
ts_real->tv_nsec = 0;

- nsecs_raw = timekeeping_get_ns_raw(tk);
+ nsecs_raw = timekeeping_get_ns_raw(&tk->tkr, false);
nsecs_real = timekeeping_get_ns(&tk->tkr);

} while (read_seqcount_retry(&tk_core.seq, seq));
@@ -966,7 +948,7 @@ void getrawmonotonic64(struct timespec64 *ts)

do {
seq = read_seqcount_begin(&tk_core.seq);
- nsecs = timekeeping_get_ns_raw(tk);
+ nsecs = timekeeping_get_ns_raw(&tk->tkr, false);
ts64 = tk->raw_time;

} while (read_seqcount_retry(&tk_core.seq, seq));
--
2.0.0


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