alarmtimer: Switch over to generic set/get/rearm routine

All required callbacks are in place. Switch the alarm timer based posix
interval timer callbacks to the common implementation and remove the
incorrect private implementation.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/20170530211657.825471962@linutronix.de

kernel/time/alarmtimer.c

@@ -515,20 +515,26 @@ static enum alarmtimer_type clock2alarm(clockid_t clockid)
 static enum alarmtimer_restart alarm_handle_timer(struct alarm *alarm,
 							ktime_t now)
 {
-	unsigned long flags;
 	struct k_itimer *ptr = container_of(alarm, struct k_itimer,
-						it.alarm.alarmtimer);
+					    it.alarm.alarmtimer);
 	enum alarmtimer_restart result = ALARMTIMER_NORESTART;
+	unsigned long flags;
+	int si_private = 0;
 
 	spin_lock_irqsave(&ptr->it_lock, flags);
-	if ((ptr->it_sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE) {
-		if (posix_timer_event(ptr, 0))
-			ptr->it_overrun++;
-	}
 
-	/* Re-add periodic timers */
-	if (ptr->it_interval) {
-		ptr->it_overrun += alarm_forward(alarm, now, ptr->it_interval);
+	ptr->it_active = 0;
+	if (ptr->it_interval)
+		si_private = ++ptr->it_requeue_pending;
+
+	if (posix_timer_event(ptr, si_private) && ptr->it_interval) {
+		/*
+		 * Handle ignored signals and rearm the timer. This will go
+		 * away once we handle ignored signals proper.
+		 */
+		ptr->it_overrun += alarm_forward_now(alarm, ptr->it_interval);
+		++ptr->it_requeue_pending;
+		ptr->it_active = 1;
 		result = ALARMTIMER_RESTART;
 	}
 	spin_unlock_irqrestore(&ptr->it_lock, flags);
@@ -658,97 +664,6 @@ static int alarm_timer_create(struct k_itimer *new_timer)
 	return 0;
 }
 
-/**
- * alarm_timer_get - posix timer_get interface
- * @timr: k_itimer pointer
- * @cur_setting: itimerspec data to fill
- *
- * Copies out the current itimerspec data
- */
-static void alarm_timer_get(struct k_itimer *timr,
-			    struct itimerspec64 *cur_setting)
-{
-	ktime_t relative_expiry_time =
-		alarm_expires_remaining(&(timr->it.alarm.alarmtimer));
-
-	if (ktime_to_ns(relative_expiry_time) > 0) {
-		cur_setting->it_value = ktime_to_timespec64(relative_expiry_time);
-	} else {
-		cur_setting->it_value.tv_sec = 0;
-		cur_setting->it_value.tv_nsec = 0;
-	}
-
-	cur_setting->it_interval = ktime_to_timespec64(timr->it_interval);
-}
-
-/**
- * alarm_timer_del - posix timer_del interface
- * @timr: k_itimer pointer to be deleted
- *
- * Cancels any programmed alarms for the given timer.
- */
-static int alarm_timer_del(struct k_itimer *timr)
-{
-	if (!rtcdev)
-		return -ENOTSUPP;
-
-	if (alarm_try_to_cancel(&timr->it.alarm.alarmtimer) < 0)
-		return TIMER_RETRY;
-
-	return 0;
-}
-
-/**
- * alarm_timer_set - posix timer_set interface
- * @timr: k_itimer pointer to be deleted
- * @flags: timer flags
- * @new_setting: itimerspec to be used
- * @old_setting: itimerspec being replaced
- *
- * Sets the timer to new_setting, and starts the timer.
- */
-static int alarm_timer_set(struct k_itimer *timr, int flags,
-			   struct itimerspec64 *new_setting,
-			   struct itimerspec64 *old_setting)
-{
-	ktime_t exp;
-
-	if (!rtcdev)
-		return -ENOTSUPP;
-
-	if (flags & ~TIMER_ABSTIME)
-		return -EINVAL;
-
-	if (old_setting)
-		alarm_timer_get(timr, old_setting);
-
-	/* If the timer was already set, cancel it */
-	if (alarm_try_to_cancel(&timr->it.alarm.alarmtimer) < 0)
-		return TIMER_RETRY;
-
-	/* start the timer */
-	timr->it_interval = timespec64_to_ktime(new_setting->it_interval);
-
-	/*
-	 * Rate limit to the tick as a hot fix to prevent DOS. Will be
-	 * mopped up later.
-	 */
-	if (timr->it_interval < TICK_NSEC)
-		timr->it_interval = TICK_NSEC;
-
-	exp = timespec64_to_ktime(new_setting->it_value);
-	/* Convert (if necessary) to absolute time */
-	if (flags != TIMER_ABSTIME) {
-		ktime_t now;
-
-		now = alarm_bases[timr->it.alarm.alarmtimer.type].gettime();
-		exp = ktime_add_safe(now, exp);
-	}
-
-	alarm_start(&timr->it.alarm.alarmtimer, exp);
-	return 0;
-}
-
 /**
  * alarmtimer_nsleep_wakeup - Wakeup function for alarm_timer_nsleep
  * @alarm: ptr to alarm that fired
@@ -926,9 +841,9 @@ const struct k_clock alarm_clock = {
 	.clock_getres		= alarm_clock_getres,
 	.clock_get		= alarm_clock_get,
 	.timer_create		= alarm_timer_create,
-	.timer_set		= alarm_timer_set,
-	.timer_del		= alarm_timer_del,
-	.timer_get		= alarm_timer_get,
+	.timer_set		= common_timer_set,
+	.timer_del		= common_timer_del,
+	.timer_get		= common_timer_get,
 	.timer_arm		= alarm_timer_arm,
 	.timer_rearm		= alarm_timer_rearm,
 	.timer_forward		= alarm_timer_forward,

kernel/time/posix-timers.c

@@ -637,8 +637,7 @@ static int common_hrtimer_forward(struct k_itimer *timr, ktime_t now)
  * it is the same as a requeue pending timer WRT to what we should
  * report.
  */
-static void
-common_timer_get(struct k_itimer *timr, struct itimerspec64 *cur_setting)
+void common_timer_get(struct k_itimer *timr, struct itimerspec64 *cur_setting)
 {
 	const struct k_clock *kc = timr->kclock;
 	ktime_t now, remaining, iv;
@@ -768,10 +767,9 @@ static int common_hrtimer_try_to_cancel(struct k_itimer *timr)
 }
 
 /* Set a POSIX.1b interval timer. */
-static int
-common_timer_set(struct k_itimer *timr, int flags,
-		 struct itimerspec64 *new_setting,
-		 struct itimerspec64 *old_setting)
+int common_timer_set(struct k_itimer *timr, int flags,
+		     struct itimerspec64 *new_setting,
+		     struct itimerspec64 *old_setting)
 {
 	const struct k_clock *kc = timr->kclock;
 	bool sigev_none;
@@ -855,7 +853,7 @@ SYSCALL_DEFINE4(timer_settime, timer_t, timer_id, int, flags,
 	return error;
 }
 
-static int common_timer_del(struct k_itimer *timer)
+int common_timer_del(struct k_itimer *timer)
 {
 	const struct k_clock *kc = timer->kclock;
 

kernel/time/posix-timers.h

@@ -33,3 +33,9 @@ extern const struct k_clock clock_thread;
 extern const struct k_clock alarm_clock;
 
 int posix_timer_event(struct k_itimer *timr, int si_private);
+
+void common_timer_get(struct k_itimer *timr, struct itimerspec64 *cur_setting);
+int common_timer_set(struct k_itimer *timr, int flags,
+		     struct itimerspec64 *new_setting,
+		     struct itimerspec64 *old_setting);
+int common_timer_del(struct k_itimer *timer);