hrtimer: Make hrtimer_reprogramm() unconditional

hrtimer_reprogram() needs to be available unconditionally for softirq based
hrtimers. Move the function and all required struct members out of the
CONFIG_HIGH_RES_TIMERS #ifdef.

There is no functional change because hrtimer_reprogram() is only invoked
when hrtimer_cpu_base.hres_active is true. Making it unconditional
increases the text size for the CONFIG_HIGH_RES_TIMERS=n case, but avoids
replication of that code for the upcoming softirq based hrtimers support.

Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: keescook@chromium.org
Link: http://lkml.kernel.org/r/20171221104205.7269-18-anna-maria@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

include/linux/hrtimer.h

@@ -182,10 +182,10 @@ struct hrtimer_cpu_base {
 	unsigned int			cpu;
 	unsigned int			active_bases;
 	unsigned int			clock_was_set_seq;
-	unsigned int			hres_active	: 1;
-#ifdef CONFIG_HIGH_RES_TIMERS
-	unsigned int			in_hrtirq	: 1,
+	unsigned int			hres_active	: 1,
+					in_hrtirq	: 1,
 					hang_detected	: 1;
+#ifdef CONFIG_HIGH_RES_TIMERS
 	unsigned int			nr_events;
 	unsigned short			nr_retries;
 	unsigned short			nr_hangs;

kernel/time/hrtimer.c

@@ -581,6 +581,70 @@ hrtimer_force_reprogram(struct hrtimer_cpu_base *cpu_base, int skip_equal)
 	tick_program_event(cpu_base->expires_next, 1);
 }
 
+/*
+ * Retrigger next event is called after clock was set
+ *
+ * Called with interrupts disabled via on_each_cpu()
+ */
+static void retrigger_next_event(void *arg)
+{
+	struct hrtimer_cpu_base *base = this_cpu_ptr(&hrtimer_bases);
+
+	if (!__hrtimer_hres_active(base))
+		return;
+
+	raw_spin_lock(&base->lock);
+	hrtimer_update_base(base);
+	hrtimer_force_reprogram(base, 0);
+	raw_spin_unlock(&base->lock);
+}
+
+/*
+ * Switch to high resolution mode
+ */
+static void hrtimer_switch_to_hres(void)
+{
+	struct hrtimer_cpu_base *base = this_cpu_ptr(&hrtimer_bases);
+
+	if (tick_init_highres()) {
+		printk(KERN_WARNING "Could not switch to high resolution "
+				    "mode on CPU %d\n", base->cpu);
+		return;
+	}
+	base->hres_active = 1;
+	hrtimer_resolution = HIGH_RES_NSEC;
+
+	tick_setup_sched_timer();
+	/* "Retrigger" the interrupt to get things going */
+	retrigger_next_event(NULL);
+}
+
+static void clock_was_set_work(struct work_struct *work)
+{
+	clock_was_set();
+}
+
+static DECLARE_WORK(hrtimer_work, clock_was_set_work);
+
+/*
+ * Called from timekeeping and resume code to reprogram the hrtimer
+ * interrupt device on all cpus.
+ */
+void clock_was_set_delayed(void)
+{
+	schedule_work(&hrtimer_work);
+}
+
+#else
+
+static inline int hrtimer_is_hres_enabled(void) { return 0; }
+static inline void hrtimer_switch_to_hres(void) { }
+static inline void
+hrtimer_force_reprogram(struct hrtimer_cpu_base *base, int skip_equal) { }
+static inline void retrigger_next_event(void *arg) { }
+
+#endif /* CONFIG_HIGH_RES_TIMERS */
+
 /*
  * When a timer is enqueued and expires earlier than the already enqueued
  * timers, we have to check, whether it expires earlier than the timer for
@@ -643,75 +707,6 @@ static void hrtimer_reprogram(struct hrtimer *timer,
 	tick_program_event(expires, 1);
 }
 
-/*
- * Retrigger next event is called after clock was set
- *
- * Called with interrupts disabled via on_each_cpu()
- */
-static void retrigger_next_event(void *arg)
-{
-	struct hrtimer_cpu_base *base = this_cpu_ptr(&hrtimer_bases);
-
-	if (!__hrtimer_hres_active(base))
-		return;
-
-	raw_spin_lock(&base->lock);
-	hrtimer_update_base(base);
-	hrtimer_force_reprogram(base, 0);
-	raw_spin_unlock(&base->lock);
-}
-
-/*
- * Switch to high resolution mode
- */
-static void hrtimer_switch_to_hres(void)
-{
-	struct hrtimer_cpu_base *base = this_cpu_ptr(&hrtimer_bases);
-
-	if (tick_init_highres()) {
-		printk(KERN_WARNING "Could not switch to high resolution "
-				    "mode on CPU %d\n", base->cpu);
-		return;
-	}
-	base->hres_active = 1;
-	hrtimer_resolution = HIGH_RES_NSEC;
-
-	tick_setup_sched_timer();
-	/* "Retrigger" the interrupt to get things going */
-	retrigger_next_event(NULL);
-}
-
-static void clock_was_set_work(struct work_struct *work)
-{
-	clock_was_set();
-}
-
-static DECLARE_WORK(hrtimer_work, clock_was_set_work);
-
-/*
- * Called from timekeeping and resume code to reprogram the hrtimer
- * interrupt device on all cpus.
- */
-void clock_was_set_delayed(void)
-{
-	schedule_work(&hrtimer_work);
-}
-
-#else
-
-static inline int hrtimer_is_hres_enabled(void) { return 0; }
-static inline void hrtimer_switch_to_hres(void) { }
-static inline void
-hrtimer_force_reprogram(struct hrtimer_cpu_base *base, int skip_equal) { }
-static inline int hrtimer_reprogram(struct hrtimer *timer,
-				    struct hrtimer_clock_base *base)
-{
-	return 0;
-}
-static inline void retrigger_next_event(void *arg) { }
-
-#endif /* CONFIG_HIGH_RES_TIMERS */
-
 /*
  * Clock realtime was set
  *