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Subject[RFC][patch 4/5] clocksource_read/clocksource_read_raw inline functions
From: Martin Schwidefsky <schwidefsky@de.ibm.com>

Add clocksource_read / clocksource_read_raw inline functions and use
them for getnstimeofday, ktime_get, ktime_get_ts and getrawmonotonic.

Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: john stultz <johnstul@us.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---
include/linux/clocksource.h | 45 +++++++++++++++++++++++++++++++++++++++++++
kernel/time/timekeeping.c | 46 +++-----------------------------------------
2 files changed, 49 insertions(+), 42 deletions(-)
Index: linux-2.6/include/linux/clocksource.h
===================================================================
--- linux-2.6.orig/include/linux/clocksource.h
+++ linux-2.6/include/linux/clocksource.h
@@ -284,6 +284,51 @@ static inline s64 cyc2ns(struct clocksou
return ret;
}

+/**
+ * clocksource_read: - Read nanosecond delta from clocksource.
+ * @cs: pointer to clocksource being read
+ *
+ * Read from the clock source and return the clock value converted
+ * to nanoseconds.
+ */
+static inline s64 clocksource_read(struct clocksource *cs)
+{
+ cycle_t cycle_now, cycle_delta;
+
+ /* read clocksource: */
+ cycle_now = cs->read(cs);
+
+ /* calculate the delta since the last update_wall_time: */
+ cycle_delta = (cycle_now - cs->cycle_last) & cs->mask;
+
+ /* convert to nanoseconds: */
+ return cyc2ns(cs, cycle_delta);
+}
+
+/**
+ * clocksource_read_raw: - Read raw nanosecond delta from clocksource.
+ * @cs: pointer to clocksource being read
+ *
+ * Read from the clock source and return the clock value converted
+ * to nanoseconds.
+ */
+static inline s64 clocksource_read_raw(struct clocksource *cs,
+ struct timespec *ts)
+{
+ cycle_t cycle_now, cycle_delta;
+
+ *ts = clock->raw_time;
+
+ /* read clocksource: */
+ cycle_now = cs->read(cs);
+
+ /* calculate the delta since the last update_wall_time: */
+ cycle_delta = (cycle_now - cs->cycle_last) & cs->mask;
+
+ /* convert to nanoseconds: */
+ return ((s64) cycle_delta * clock->mult_orig) >> clock->shift;
+}
+
/* used to install a new clocksource */
extern void __init clocksource_init(void);
extern int clocksource_register(struct clocksource*);
Index: linux-2.6/kernel/time/timekeeping.c
===================================================================
--- linux-2.6.orig/kernel/time/timekeeping.c
+++ linux-2.6/kernel/time/timekeeping.c
@@ -66,7 +66,6 @@ void update_xtime_cache(u64 nsec)
*/
void getnstimeofday(struct timespec *ts)
{
- cycle_t cycle_now, cycle_delta;
unsigned long seq;
s64 nsecs;

@@ -76,15 +75,7 @@ void getnstimeofday(struct timespec *ts)
seq = read_seqbegin(&xtime_lock);

*ts = xtime;
-
- /* read clocksource: */
- 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 = cyc2ns(clock, cycle_delta);
+ nsecs = clocksource_read(clock);

/* If arch requires, add in gettimeoffset() */
nsecs += arch_gettimeoffset();
@@ -98,7 +89,6 @@ EXPORT_SYMBOL(getnstimeofday);

ktime_t ktime_get(void)
{
- cycle_t cycle_now, cycle_delta;
unsigned int seq;
s64 secs, nsecs;

@@ -108,15 +98,7 @@ 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: */
- 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 += cyc2ns(clock, cycle_delta);
+ nsecs += clocksource_read(clock);

} while (read_seqretry(&xtime_lock, seq));
/*
@@ -137,7 +119,6 @@ EXPORT_SYMBOL_GPL(ktime_get);
*/
void ktime_get_ts(struct timespec *ts)
{
- cycle_t cycle_now, cycle_delta;
struct timespec tomono;
unsigned int seq;
s64 nsecs;
@@ -148,15 +129,7 @@ void ktime_get_ts(struct timespec *ts)
seq = read_seqbegin(&xtime_lock);
*ts = xtime;
tomono = wall_to_monotonic;
-
- /* read clocksource: */
- 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 = cyc2ns(clock, cycle_delta);
+ nsecs = clocksource_read(clock);

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

@@ -290,21 +263,10 @@ void getrawmonotonic(struct timespec *ts
{
unsigned long seq;
s64 nsecs;
- cycle_t cycle_now, cycle_delta;

do {
seq = read_seqbegin(&xtime_lock);
-
- /* read clocksource: */
- 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 = ((s64)cycle_delta * clock->mult_orig) >> clock->shift;
-
- *ts = clock->raw_time;
+ nsecs = clocksource_read_raw(clock, ts);

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

--
blue skies,
Martin.

"Reality continues to ruin my life." - Calvin.



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