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Commit 2ba2a305 authored by Martin Schwidefsky's avatar Martin Schwidefsky Committed by Thomas Gleixner
Browse files

timekeeping: Add timekeeper read_clock helper functions 



Add timekeeper_read_clock_ntp and timekeeper_read_clock_raw and use
them for getnstimeofday, ktime_get, ktime_get_ts and getrawmonotonic.

Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: default avatarJohn Stultz <johnstul@us.ibm.com>
Cc: Daniel Walker <dwalker@fifo99.com>
LKML-Reference: <20090814134810.435105711@de.ibm.com>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent 0a544198

kernel/time/timekeeping.c

+38 −53
Original line number Diff line number Diff line
@@ -95,6 +95,40 @@ static void timekeeper_setup_internals(struct clocksource *clock) 
	timekeeper.mult = clock->mult;

}



/* Timekeeper helper functions. */

static inline s64 timekeeping_get_ns(void)

{

	cycle_t cycle_now, cycle_delta;

	struct clocksource *clock;



	/* read clocksource: */

	clock = timekeeper.clock;

	cycle_now = clock->read(clock);



	/* calculate the delta since the last update_wall_time: */

	cycle_delta = (cycle_now - clock->cycle_last) & clock->mask;



	/* return delta convert to nanoseconds using ntp adjusted mult. */

	return clocksource_cyc2ns(cycle_delta, timekeeper.mult,

				  timekeeper.shift);

}



static inline s64 timekeeping_get_ns_raw(void)

{

	cycle_t cycle_now, cycle_delta;

	struct clocksource *clock;



	/* read clocksource: */

	clock = timekeeper.clock;

	cycle_now = clock->read(clock);



	/* calculate the delta since the last update_wall_time: */

	cycle_delta = (cycle_now - clock->cycle_last) & clock->mask;



	/* return delta convert to nanoseconds using ntp adjusted mult. */

	return clocksource_cyc2ns(cycle_delta, clock->mult, clock->shift);

}



/*

 * This read-write spinlock protects us from races in SMP while

 * playing with xtime.
@@ -183,8 +217,6 @@ static void timekeeping_forward_now(void) 
 */

void getnstimeofday(struct timespec *ts)

{

	cycle_t cycle_now, cycle_delta;

	struct clocksource *clock;

	unsigned long seq;

	s64 nsecs;
@@ -194,17 +226,7 @@ void getnstimeofday(struct timespec *ts) 
		seq = read_seqbegin(&xtime_lock);



		*ts = xtime;



		/* read clocksource: */

		clock = timekeeper.clock;

		cycle_now = clock->read(clock);



		/* calculate the delta since the last update_wall_time: */

		cycle_delta = (cycle_now - clock->cycle_last) & clock->mask;



		/* convert to nanoseconds: */

		nsecs = clocksource_cyc2ns(cycle_delta, timekeeper.mult,

					   timekeeper.shift);

		nsecs = timekeeping_get_ns();



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

		nsecs += arch_gettimeoffset();
@@ -218,8 +240,6 @@ EXPORT_SYMBOL(getnstimeofday); 


ktime_t ktime_get(void)

{

	cycle_t cycle_now, cycle_delta;

	struct clocksource *clock;

	unsigned int seq;

	s64 secs, nsecs;
@@ -229,17 +249,7 @@ ktime_t ktime_get(void) 
		seq = read_seqbegin(&xtime_lock);

		secs = xtime.tv_sec + wall_to_monotonic.tv_sec;

		nsecs = xtime.tv_nsec + wall_to_monotonic.tv_nsec;



		/* read clocksource: */

		clock = timekeeper.clock;

		cycle_now = clock->read(clock);



		/* calculate the delta since the last update_wall_time: */

		cycle_delta = (cycle_now - clock->cycle_last) & clock->mask;



		/* convert to nanoseconds: */

		nsecs += clocksource_cyc2ns(cycle_delta, timekeeper.mult,

					    timekeeper.shift);

		nsecs += timekeeping_get_ns();



	} while (read_seqretry(&xtime_lock, seq));

	/*
@@ -260,8 +270,6 @@ EXPORT_SYMBOL_GPL(ktime_get); 
 */

void ktime_get_ts(struct timespec *ts)

{

	cycle_t cycle_now, cycle_delta;

	struct clocksource *clock;

	struct timespec tomono;

	unsigned int seq;

	s64 nsecs;
@@ -272,17 +280,7 @@ void ktime_get_ts(struct timespec *ts) 
		seq = read_seqbegin(&xtime_lock);

		*ts = xtime;

		tomono = wall_to_monotonic;



		/* read clocksource: */

		clock = timekeeper.clock;

		cycle_now = clock->read(clock);



		/* calculate the delta since the last update_wall_time: */

		cycle_delta = (cycle_now - clock->cycle_last) & clock->mask;



		/* convert to nanoseconds: */

		nsecs = clocksource_cyc2ns(cycle_delta, timekeeper.mult,

					   timekeeper.shift);

		nsecs = timekeeping_get_ns();



	} while (read_seqretry(&xtime_lock, seq));
@@ -445,23 +443,10 @@ void getrawmonotonic(struct timespec *ts) 
{

	unsigned long seq;

	s64 nsecs;

	cycle_t cycle_now, cycle_delta;

	struct clocksource *clock;



	do {

		seq = read_seqbegin(&xtime_lock);



		/* read clocksource: */

		clock = timekeeper.clock;

		cycle_now = clock->read(clock);



		/* calculate the delta since the last update_wall_time: */

		cycle_delta = (cycle_now - clock->cycle_last) & clock->mask;



		/* convert to nanoseconds: */

		nsecs = clocksource_cyc2ns(cycle_delta, clock->mult,

					   clock->shift);



		nsecs = timekeeping_get_ns_raw();

		*ts = raw_time;



	} while (read_seqretry(&xtime_lock, seq));