timekeeping: Store cycle_last value in timekeeper struct as well
For implementing a shadow timekeeper and a split calculation/update
region we need to store the cycle_last value in the timekeeper and
update the value in the clocksource struct only in the update region.
Add the extra storage to the timekeeper.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>
diff --git a/include/linux/timekeeper_internal.h b/include/linux/timekeeper_internal.h
index a151bd7..c1825eb 100644
--- a/include/linux/timekeeper_internal.h
+++ b/include/linux/timekeeper_internal.h
@@ -20,6 +20,8 @@
u32 shift;
/* Number of clock cycles in one NTP interval. */
cycle_t cycle_interval;
+ /* Last cycle value (also stored in clock->cycle_last) */
+ cycle_t cycle_last;
/* Number of clock shifted nano seconds in one NTP interval. */
u64 xtime_interval;
/* shifted nano seconds left over when rounding cycle_interval */
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index f93f60c..4c276b2d 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -101,7 +101,7 @@
old_clock = tk->clock;
tk->clock = clock;
- clock->cycle_last = clock->read(clock);
+ tk->cycle_last = clock->cycle_last = clock->read(clock);
/* Do the ns -> cycle conversion first, using original mult */
tmp = NTP_INTERVAL_LENGTH;
@@ -266,7 +266,7 @@
clock = tk->clock;
cycle_now = clock->read(clock);
cycle_delta = (cycle_now - clock->cycle_last) & clock->mask;
- clock->cycle_last = cycle_now;
+ tk->cycle_last = clock->cycle_last = cycle_now;
tk->xtime_nsec += cycle_delta * tk->mult;