timekeeping: Simplify arch_gettimeoffset()

Provide a default stub function instead of having the extra
conditional. Cuts binary size on a m68k build by ~100 bytes.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>

kernel/time/timekeeping.c

@@ -153,16 +153,10 @@ static void tk_setup_internals(struct timekeeper *tk, struct clocksource *clock)
 /* Timekeeper helper functions. */
 
 #ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
-u32 (*arch_gettimeoffset)(void);
-
-u32 get_arch_timeoffset(void)
-{
-	if (likely(arch_gettimeoffset))
-		return arch_gettimeoffset();
-	return 0;
-}
+static u32 default_arch_gettimeoffset(void) { return 0; }
+u32 (*arch_gettimeoffset)(void) = default_arch_gettimeoffset;
 #else
-static inline u32 get_arch_timeoffset(void) { return 0; }
+static inline u32 arch_gettimeoffset(void) { return 0; }
 #endif
 
 static inline s64 timekeeping_get_ns(struct timekeeper *tk)
@@ -182,7 +176,7 @@ static inline s64 timekeeping_get_ns(struct timekeeper *tk)
 	nsec >>= tk->shift;
 
 	/* If arch requires, add in get_arch_timeoffset() */
-	return nsec + get_arch_timeoffset();
+	return nsec + arch_gettimeoffset();
 }
 
 static inline s64 timekeeping_get_ns_raw(struct timekeeper *tk)
@@ -202,7 +196,7 @@ static inline s64 timekeeping_get_ns_raw(struct timekeeper *tk)
 	nsec = clocksource_cyc2ns(cycle_delta, clock->mult, clock->shift);
 
 	/* If arch requires, add in get_arch_timeoffset() */
-	return nsec + get_arch_timeoffset();
+	return nsec + arch_gettimeoffset();
 }
 
 static RAW_NOTIFIER_HEAD(pvclock_gtod_chain);
@@ -282,7 +276,7 @@ static void timekeeping_forward_now(struct timekeeper *tk)
 	tk->xtime_nsec += cycle_delta * tk->mult;
 
 	/* If arch requires, add in get_arch_timeoffset() */
-	tk->xtime_nsec += (u64)get_arch_timeoffset() << tk->shift;
+	tk->xtime_nsec += (u64)arch_gettimeoffset() << tk->shift;
 
 	tk_normalize_xtime(tk);