timers: Remove unused __round_jiffies(_up)

Remove two trivial but long unused functions.

__round_jiffies() has been unused since 2008's
commit 9c133c4 ("Add round_jiffies_up and related routines")

__round_jiffies_up() has been unused since 2019's
commit 7ae3f6e ("powerpc/watchdog: Use hrtimers for per-CPU
heartbeat")

Remove them.

Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20250418200803.427911-1-linux@treblig.org

Author: Dr. David Alan Gilbert

include/linux/timer.h

@@ -172,12 +172,10 @@ extern void init_timers(void);
 struct hrtimer;
 extern enum hrtimer_restart it_real_fn(struct hrtimer *);
 
-unsigned long __round_jiffies(unsigned long j, int cpu);
 unsigned long __round_jiffies_relative(unsigned long j, int cpu);
 unsigned long round_jiffies(unsigned long j);
 unsigned long round_jiffies_relative(unsigned long j);
 
-unsigned long __round_jiffies_up(unsigned long j, int cpu);
 unsigned long __round_jiffies_up_relative(unsigned long j, int cpu);
 unsigned long round_jiffies_up(unsigned long j);
 unsigned long round_jiffies_up_relative(unsigned long j);

kernel/time/timer.c

@@ -385,32 +385,6 @@ static unsigned long round_jiffies_common(unsigned long j, int cpu,
 	return time_is_after_jiffies(j) ? j : original;
 }
 
-/**
- * __round_jiffies - function to round jiffies to a full second
- * @j: the time in (absolute) jiffies that should be rounded
- * @cpu: the processor number on which the timeout will happen
- *
- * __round_jiffies() rounds an absolute time in the future (in jiffies)
- * up or down to (approximately) full seconds. This is useful for timers
- * for which the exact time they fire does not matter too much, as long as
- * they fire approximately every X seconds.
- *
- * By rounding these timers to whole seconds, all such timers will fire
- * at the same time, rather than at various times spread out. The goal
- * of this is to have the CPU wake up less, which saves power.
- *
- * The exact rounding is skewed for each processor to avoid all
- * processors firing at the exact same time, which could lead
- * to lock contention or spurious cache line bouncing.
- *
- * The return value is the rounded version of the @j parameter.
- */
-unsigned long __round_jiffies(unsigned long j, int cpu)
-{
-	return round_jiffies_common(j, cpu, false);
-}
-EXPORT_SYMBOL_GPL(__round_jiffies);
-
 /**
  * __round_jiffies_relative - function to round jiffies to a full second
  * @j: the time in (relative) jiffies that should be rounded
@@ -482,22 +456,6 @@ unsigned long round_jiffies_relative(unsigned long j)
 }
 EXPORT_SYMBOL_GPL(round_jiffies_relative);
 
-/**
- * __round_jiffies_up - function to round jiffies up to a full second
- * @j: the time in (absolute) jiffies that should be rounded
- * @cpu: the processor number on which the timeout will happen
- *
- * This is the same as __round_jiffies() except that it will never
- * round down.  This is useful for timeouts for which the exact time
- * of firing does not matter too much, as long as they don't fire too
- * early.
- */
-unsigned long __round_jiffies_up(unsigned long j, int cpu)
-{
-	return round_jiffies_common(j, cpu, true);
-}
-EXPORT_SYMBOL_GPL(__round_jiffies_up);
-
 /**
  * __round_jiffies_up_relative - function to round jiffies up to a full second
  * @j: the time in (relative) jiffies that should be rounded