Commit fc6eead7 authored by John Stultz's avatar John Stultz
Browse files

time: Clean up CLOCK_MONOTONIC_RAW time handling 



Now that we fixed the sub-ns handling for CLOCK_MONOTONIC_RAW,
remove the duplicitive tk->raw_time.tv_nsec, which can be
stored in tk->tkr_raw.xtime_nsec (similarly to how its handled
for monotonic time).

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Miroslav Lichvar <mlichvar@redhat.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Stephen Boyd <stephen.boyd@linaro.org>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Daniel Mentz <danielmentz@google.com>
Tested-by: default avatarDaniel Mentz <danielmentz@google.com>
Signed-off-by: default avatarJohn Stultz <john.stultz@linaro.org>
parent 8e6cec1c

arch/arm64/kernel/vdso.c

+2 −4
Original line number Diff line number Diff line
@@ -220,10 +220,8 @@ void update_vsyscall(struct timekeeper *tk) 
	if (!use_syscall) {

		/* tkr_mono.cycle_last == tkr_raw.cycle_last */

		vdso_data->cs_cycle_last	= tk->tkr_mono.cycle_last;

		vdso_data->raw_time_sec		= tk->raw_time.tv_sec;

		vdso_data->raw_time_nsec	= (tk->raw_time.tv_nsec <<

						   tk->tkr_raw.shift) +

						  tk->tkr_raw.xtime_nsec;

		vdso_data->raw_time_sec         = tk->raw_sec;

		vdso_data->raw_time_nsec        = tk->tkr_raw.xtime_nsec;

		vdso_data->xtime_clock_sec	= tk->xtime_sec;

		vdso_data->xtime_clock_nsec	= tk->tkr_mono.xtime_nsec;

		vdso_data->cs_mono_mult		= tk->tkr_mono.mult;

include/linux/timekeeper_internal.h

+2 −2
Original line number Diff line number Diff line
@@ -51,7 +51,7 @@ struct tk_read_base { 
 * @clock_was_set_seq:	The sequence number of clock was set events

 * @cs_was_changed_seq:	The sequence number of clocksource change events

 * @next_leap_ktime:	CLOCK_MONOTONIC time value of a pending leap-second

 * @raw_time:		Monotonic raw base time in timespec64 format

 * @raw_sec:		CLOCK_MONOTONIC_RAW  time in seconds

 * @cycle_interval:	Number of clock cycles in one NTP interval

 * @xtime_interval:	Number of clock shifted nano seconds in one NTP

 *			interval.
@@ -93,7 +93,7 @@ struct timekeeper { 
	unsigned int		clock_was_set_seq;

	u8			cs_was_changed_seq;

	ktime_t			next_leap_ktime;

	struct timespec64	raw_time;

	u64			raw_sec;



	/* The following members are for timekeeping internal use */

	u64			cycle_interval;

kernel/time/timekeeping.c

+25 −20
Original line number Diff line number Diff line
@@ -72,6 +72,10 @@ static inline void tk_normalize_xtime(struct timekeeper *tk) 
		tk->tkr_mono.xtime_nsec -= (u64)NSEC_PER_SEC << tk->tkr_mono.shift;

		tk->xtime_sec++;

	}

	while (tk->tkr_raw.xtime_nsec >= ((u64)NSEC_PER_SEC << tk->tkr_raw.shift)) {

		tk->tkr_raw.xtime_nsec -= (u64)NSEC_PER_SEC << tk->tkr_raw.shift;

		tk->raw_sec++;

	}

}



static inline struct timespec64 tk_xtime(struct timekeeper *tk)
@@ -285,12 +289,14 @@ static void tk_setup_internals(struct timekeeper *tk, struct clocksource *clock) 
	 /* if changing clocks, convert xtime_nsec shift units */

	if (old_clock) {

		int shift_change = clock->shift - old_clock->shift;

		if (shift_change < 0)

		if (shift_change < 0) {

			tk->tkr_mono.xtime_nsec >>= -shift_change;

		else

			tk->tkr_raw.xtime_nsec >>= -shift_change;

		} else {

			tk->tkr_mono.xtime_nsec <<= shift_change;

			tk->tkr_raw.xtime_nsec <<= shift_change;

		}

	}

	tk->tkr_raw.xtime_nsec = 0;



	tk->tkr_mono.shift = clock->shift;

	tk->tkr_raw.shift = clock->shift;
@@ -619,9 +625,6 @@ static inline void tk_update_ktime_data(struct timekeeper *tk) 
	nsec = (u32) tk->wall_to_monotonic.tv_nsec;

	tk->tkr_mono.base = ns_to_ktime(seconds * NSEC_PER_SEC + nsec);



	/* Update the monotonic raw base */

	tk->tkr_raw.base = timespec64_to_ktime(tk->raw_time);



	/*

	 * The sum of the nanoseconds portions of xtime and

	 * wall_to_monotonic can be greater/equal one second. Take
@@ -631,6 +634,11 @@ static inline void tk_update_ktime_data(struct timekeeper *tk) 
	if (nsec >= NSEC_PER_SEC)

		seconds++;

	tk->ktime_sec = seconds;



	/* Update the monotonic raw base */

	seconds = tk->raw_sec;

	nsec = (u32)(tk->tkr_raw.xtime_nsec >> tk->tkr_raw.shift);

	tk->tkr_raw.base = ns_to_ktime(seconds * NSEC_PER_SEC + nsec);

}



/* must hold timekeeper_lock */
@@ -672,7 +680,6 @@ static void timekeeping_update(struct timekeeper *tk, unsigned int action) 
static void timekeeping_forward_now(struct timekeeper *tk)

{

	u64 cycle_now, delta;

	u64 nsec;



	cycle_now = tk_clock_read(&tk->tkr_mono);

	delta = clocksource_delta(cycle_now, tk->tkr_mono.cycle_last, tk->tkr_mono.mask);
@@ -684,10 +691,13 @@ static void timekeeping_forward_now(struct timekeeper *tk) 
	/* If arch requires, add in get_arch_timeoffset() */

	tk->tkr_mono.xtime_nsec += (u64)arch_gettimeoffset() << tk->tkr_mono.shift;



	tk_normalize_xtime(tk);



	nsec = clocksource_cyc2ns(delta, tk->tkr_raw.mult, tk->tkr_raw.shift);

	timespec64_add_ns(&tk->raw_time, nsec);

	tk->tkr_raw.xtime_nsec += delta * tk->tkr_raw.mult;



	/* If arch requires, add in get_arch_timeoffset() */

	tk->tkr_raw.xtime_nsec += (u64)arch_gettimeoffset() << tk->tkr_raw.shift;



	tk_normalize_xtime(tk);

}



/**
@@ -1373,19 +1383,18 @@ int timekeeping_notify(struct clocksource *clock) 
void getrawmonotonic64(struct timespec64 *ts)

{

	struct timekeeper *tk = &tk_core.timekeeper;

	struct timespec64 ts64;

	unsigned long seq;

	u64 nsecs;



	do {

		seq = read_seqcount_begin(&tk_core.seq);

		ts->tv_sec = tk->raw_sec;

		nsecs = timekeeping_get_ns(&tk->tkr_raw);

		ts64 = tk->raw_time;



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



	timespec64_add_ns(&ts64, nsecs);

	*ts = ts64;

	ts->tv_nsec = 0;

	timespec64_add_ns(ts, nsecs);

}

EXPORT_SYMBOL(getrawmonotonic64);
@@ -1509,8 +1518,7 @@ void __init timekeeping_init(void) 
	tk_setup_internals(tk, clock);



	tk_set_xtime(tk, &now);

	tk->raw_time.tv_sec = 0;

	tk->raw_time.tv_nsec = 0;

	tk->raw_sec = 0;

	if (boot.tv_sec == 0 && boot.tv_nsec == 0)

		boot = tk_xtime(tk);
@@ -2011,15 +2019,12 @@ static u64 logarithmic_accumulation(struct timekeeper *tk, u64 offset, 
	*clock_set |= accumulate_nsecs_to_secs(tk);



	/* Accumulate raw time */

	tk->tkr_raw.xtime_nsec += (u64)tk->raw_time.tv_nsec << tk->tkr_raw.shift;

	tk->tkr_raw.xtime_nsec += tk->raw_interval << shift;

	snsec_per_sec = (u64)NSEC_PER_SEC << tk->tkr_raw.shift;

	while (tk->tkr_raw.xtime_nsec >= snsec_per_sec) {

		tk->tkr_raw.xtime_nsec -= snsec_per_sec;

		tk->raw_time.tv_sec++;

		tk->raw_sec++;

	}

	tk->raw_time.tv_nsec = tk->tkr_raw.xtime_nsec >> tk->tkr_raw.shift;

	tk->tkr_raw.xtime_nsec -= (u64)tk->raw_time.tv_nsec << tk->tkr_raw.shift;



	/* Accumulate error between NTP and clock interval */

	tk->ntp_error += tk->ntp_tick << shift;

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