ktime: Sanitize ktime_to_us/ms conversion

With the plain nanoseconds based ktime_t we can simply use
ktime_divns() instead of going through loops and hoops of
timespec/timeval conversion.
Reported-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>

include/linux/hrtimer.h

@@ -457,12 +457,6 @@ extern void hrtimer_run_pending(void);
 /* Bootup initialization: */
 extern void __init hrtimers_init(void);
 
-#if BITS_PER_LONG < 64
-extern u64 ktime_divns(const ktime_t kt, s64 div);
-#else /* BITS_PER_LONG < 64 */
-# define ktime_divns(kt, div)		(u64)((kt).tv64 / (div))
-#endif
-
 /* Show pending timers: */
 extern void sysrq_timer_list_show(void);
 

include/linux/ktime.h

@@ -157,16 +157,20 @@ static inline bool ktime_before(const ktime_t cmp1, const ktime_t cmp2)
 	return ktime_compare(cmp1, cmp2) < 0;
 }
 
+#if BITS_PER_LONG < 64
+extern u64 ktime_divns(const ktime_t kt, s64 div);
+#else /* BITS_PER_LONG < 64 */
+# define ktime_divns(kt, div)		(u64)((kt).tv64 / (div))
+#endif
+
 static inline s64 ktime_to_us(const ktime_t kt)
 {
-	struct timeval tv = ktime_to_timeval(kt);
-	return (s64) tv.tv_sec * USEC_PER_SEC + tv.tv_usec;
+	return ktime_divns(kt, NSEC_PER_USEC);
 }
 
 static inline s64 ktime_to_ms(const ktime_t kt)
 {
-	struct timeval tv = ktime_to_timeval(kt);
-	return (s64) tv.tv_sec * MSEC_PER_SEC + tv.tv_usec / USEC_PER_MSEC;
+	return ktime_divns(kt, NSEC_PER_MSEC);
 }
 
 static inline s64 ktime_us_delta(const ktime_t later, const ktime_t earlier)

kernel/time/hrtimer.c

@@ -280,6 +280,7 @@ u64 ktime_divns(const ktime_t kt, s64 div)
 
 	return dclc;
 }
+EXPORT_SYMBOL_GPL(ktime_divns);
 #endif /* BITS_PER_LONG >= 64 */
 
 /*