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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: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: John Stultz <johnstul@us.ibm.com>
Cc: Daniel Walker <dwalker@fifo99.com>
LKML-Reference: <20090814134810.435105711@de.ibm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Martin Schwidefsky 2009-08-14 15:47:29 +02:00 committed by Thomas Gleixner
parent 0a54419836
commit 2ba2a3054f
1 changed files with 38 additions and 53 deletions
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91
kernel/time/timekeeping.c
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@ -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));