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Subject[tip:timers/core] timekeeping: Add timekeeper read_clock helper functions
Commit-ID:  2ba2a3054fdffc8e6452f4ee120760322a6fbd43
Gitweb: http://git.kernel.org/tip/2ba2a3054fdffc8e6452f4ee120760322a6fbd43
Author: Martin Schwidefsky <schwidefsky@de.ibm.com>
AuthorDate: Fri, 14 Aug 2009 15:47:29 +0200
Committer: Thomas Gleixner <tglx@linutronix.de>
CommitDate: Sat, 15 Aug 2009 10:55:46 +0200

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>


---
kernel/time/timekeeping.c | 91 +++++++++++++++++++--------------------------
1 files changed, 38 insertions(+), 53 deletions(-)

diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index f4056f6..27ae01b 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -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));

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