2 files changed, 19 insertions, 20 deletions

diff --git a/include/linux/timekeeper_internal.h b/include/linux/timekeeper_internal.h
index cb88096222c0..75bb8add78f5 100644
--- a/include/linux/timekeeper_internal.h
+++ b/include/linux/timekeeper_internal.h
@@ -29,6 +29,10 @@
 struct timekeeper {
         /* Current clocksource used for timekeeping. */
         struct clocksource      *clock;
+        /* Read function of @clock */
+        cycle_t                 (*read)(struct clocksource *cs);
+        /* Bitmask for two's complement subtraction of non 64bit counters */
+        cycle_t                 mask;
         /* Last cycle value */
         cycle_t                 cycle_last;
         /* NTP adjusted clock multiplier */
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index 4e748c404749..14b7367e6b94 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -121,7 +121,9 @@ static void tk_setup_internals(struct timekeeper *tk, struct clocksource *clock)
 
         old_clock = tk->clock;
         tk->clock = clock;
-        tk->cycle_last = clock->read(clock);
+        tk->read = clock->read;
+        tk->mask = clock->mask;
+        tk->cycle_last = tk->read(clock);
 
         /* Do the ns -> cycle conversion first, using original mult */
         tmp = NTP_INTERVAL_LENGTH;
@@ -174,15 +176,13 @@ static inline u32 arch_gettimeoffset(void) { return 0; }
 static inline s64 timekeeping_get_ns(struct timekeeper *tk)
 {
         cycle_t cycle_now, delta;
-        struct clocksource *clock;
         s64 nsec;
 
         /* read clocksource: */
-        clock = tk->clock;
-        cycle_now = clock->read(clock);
+        cycle_now = tk->read(tk->clock);
 
         /* calculate the delta since the last update_wall_time: */
-        delta = clocksource_delta(cycle_now, tk->cycle_last, clock->mask);
+        delta = clocksource_delta(cycle_now, tk->cycle_last, tk->mask);
 
         nsec = delta * tk->mult + tk->xtime_nsec;
         nsec >>= tk->shift;
@@ -193,16 +193,15 @@ static inline s64 timekeeping_get_ns(struct timekeeper *tk)
 
 static inline s64 timekeeping_get_ns_raw(struct timekeeper *tk)
 {
+        struct clocksource *clock = tk->clock;
         cycle_t cycle_now, delta;
-        struct clocksource *clock;
         s64 nsec;
 
         /* read clocksource: */
-        clock = tk->clock;
-        cycle_now = clock->read(clock);
+        cycle_now = tk->read(clock);
 
         /* calculate the delta since the last update_wall_time: */
-        delta = clocksource_delta(cycle_now, tk->cycle_last, clock->mask);
+        delta = clocksource_delta(cycle_now, tk->cycle_last, tk->mask);
 
         /* convert delta to nanoseconds. */
         nsec = clocksource_cyc2ns(delta, clock->mult, clock->shift);
@@ -337,13 +336,12 @@ static void timekeeping_update(struct timekeeper *tk, unsigned int action)
  */
 static void timekeeping_forward_now(struct timekeeper *tk)
 {
+        struct clocksource *clock = tk->clock;
         cycle_t cycle_now, delta;
-        struct clocksource *clock;
         s64 nsec;
 
-        clock = tk->clock;
-        cycle_now = clock->read(clock);
-        delta = clocksource_delta(cycle_now, tk->cycle_last, clock->mask);
+        cycle_now = tk->read(clock);
+        delta = clocksource_delta(cycle_now, tk->cycle_last, tk->mask);
         tk->cycle_last = cycle_now;
 
         tk->xtime_nsec += delta * tk->mult;
@@ -1019,7 +1017,7 @@ static void timekeeping_resume(void)
          * The less preferred source will only be tried if there is no better
          * usable source. The rtc part is handled separately in rtc core code.
          */
-        cycle_now = clock->read(clock);
+        cycle_now = tk->read(clock);
         if ((clock->flags & CLOCK_SOURCE_SUSPEND_NONSTOP) &&
                 cycle_now > tk->cycle_last) {
                 u64 num, max = ULLONG_MAX;
@@ -1028,7 +1026,7 @@ static void timekeeping_resume(void)
                 s64 nsec = 0;
 
                 cycle_delta = clocksource_delta(cycle_now, tk->cycle_last,
-                                                clock->mask);
+                                                tk->mask);
 
                 /*
                  * "cycle_delta * mutl" may cause 64 bits overflow, if the
@@ -1415,7 +1413,6 @@ static cycle_t logarithmic_accumulation(struct timekeeper *tk, cycle_t offset,
  */
 void update_wall_time(void)
 {
-        struct clocksource *clock;
         struct timekeeper *real_tk = &tk_core.timekeeper;
         struct timekeeper *tk = &shadow_timekeeper;
         cycle_t offset;
@@ -1429,13 +1426,11 @@ void update_wall_time(void)
         if (unlikely(timekeeping_suspended))
                 goto out;
 
-        clock = real_tk->clock;
-
 #ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
         offset = real_tk->cycle_interval;
 #else
-        offset = clocksource_delta(clock->read(clock), tk->cycle_last,
-                                   clock->mask);
+        offset = clocksource_delta(tk->read(tk->clock), tk->cycle_last,
+                                   tk->mask);
 #endif
 
         /* Check if there's really nothing to do */