Merge tag 'fortglx-3.20-time' of https://git.linaro.org/people/john.stultz/linux into timers/core

Pull time updates from John Stultz for 3.20:

 * ktime division optimization
 * Expose a few more y2038-safe timekeeping interfaces
 * RTC core changes to address y2038

1 files changed, 11 insertions, 1 deletions

diff --git a/include/linux/ktime.h b/include/linux/ktime.h
index 891ea92a68b0..5fc3d1083071 100644
--- a/include/linux/ktime.h
+++ b/include/linux/ktime.h
@@ -166,7 +166,17 @@ static inline bool ktime_before(const ktime_t cmp1, const ktime_t cmp2)
 }
 
 #if BITS_PER_LONG < 64
-extern u64 ktime_divns(const ktime_t kt, s64 div);
+extern u64 __ktime_divns(const ktime_t kt, s64 div);
+static inline u64 ktime_divns(const ktime_t kt, s64 div)
+{
+        if (__builtin_constant_p(div) && !(div >> 32)) {
+                u64 ns = kt.tv64;
+                do_div(ns, div);
+                return ns;
+        } else {
+                return __ktime_divns(kt, div);
+        }
+}
 #else /* BITS_PER_LONG < 64 */
 # define ktime_divns(kt, div)           (u64)((kt).tv64 / (div))
 #endif