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>

diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index f4056f6c263284f89d3e2f77ad17bbf0657b4d0a..27ae01b596b77790d1dbe7226cf7cb4c7144d804 100644 (file)
--- 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));