timers: Split out forward timer base functionality

Forwarding timer base is done when the next expiry value is calculated and
when a new timer is enqueued. When the next expiry value is calculated the
jiffies value is already available and does not need to be reread a second
time.

Splitting out the forward timer base functionality to make it executable
via both contextes - those where jiffies are already known and those, where
jiffies need to be read.

No functional change.

Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20231201092654.34614-10-anna-maria@linutronix.de

diff --git a/kernel/time/timer.c b/kernel/time/timer.c
index f75f932b128e8170bfcf091427547d9373ecf44f..5b02e169ab236faaf7ecc6fbbc3f665d0cd8a2b4 100644 (file)
--- a/kernel/time/timer.c
+++ b/kernel/time/timer.c
@@ -939,30 +939,34 @@ get_target_base(struct timer_base *base, unsigned tflags)
        return get_timer_this_cpu_base(tflags);
 }
 
-static inline void forward_timer_base(struct timer_base *base)
+static inline void __forward_timer_base(struct timer_base *base,
+                                       unsigned long basej)
 {
-       unsigned long jnow = READ_ONCE(jiffies);
-
        /*
         * Check whether we can forward the base. We can only do that when
         * @basej is past base->clk otherwise we might rewind base->clk.
         */
-       if (time_before_eq(jnow, base->clk))
+       if (time_before_eq(basej, base->clk))
                return;
 
        /*
         * If the next expiry value is > jiffies, then we fast forward to
         * jiffies otherwise we forward to the next expiry value.
         */
-       if (time_after(base->next_expiry, jnow)) {
-               base->clk = jnow;
+       if (time_after(base->next_expiry, basej)) {
+               base->clk = basej;
        } else {
                if (WARN_ON_ONCE(time_before(base->next_expiry, base->clk)))
                        return;
                base->clk = base->next_expiry;
        }
+
 }
 
+static inline void forward_timer_base(struct timer_base *base)
+{
+       __forward_timer_base(base, READ_ONCE(jiffies));
+}
 
 /*
  * We are using hashed locking: Holding per_cpu(timer_bases[x]).lock means