ALSA: seq: timer: Use guard() for locking

We can simplify the code gracefully with new guard() macro and co for
automatic cleanup of locks.

Only the code refactoring, and no functional changes.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://lore.kernel.org/r/20240227085306.9764-17-tiwai@suse.de

sound/core/seq/seq_timer.c

@@ -75,9 +75,7 @@ void snd_seq_timer_delete(struct snd_seq_timer **tmr)
 
 void snd_seq_timer_defaults(struct snd_seq_timer * tmr)
 {
-	unsigned long flags;
-
-	spin_lock_irqsave(&tmr->lock, flags);
+	guard(spinlock_irqsave)(&tmr->lock);
 	/* setup defaults */
 	tmr->ppq = 96;		/* 96 PPQ */
 	tmr->tempo = 500000;	/* 120 BPM */
@@ -93,7 +91,6 @@ void snd_seq_timer_defaults(struct snd_seq_timer * tmr)
 	tmr->preferred_resolution = seq_default_timer_resolution;
 
 	tmr->skew = tmr->skew_base = SKEW_BASE;
-	spin_unlock_irqrestore(&tmr->lock, flags);
 }
 
 static void seq_timer_reset(struct snd_seq_timer *tmr)
@@ -108,11 +105,8 @@ static void seq_timer_reset(struct snd_seq_timer *tmr)
 
 void snd_seq_timer_reset(struct snd_seq_timer *tmr)
 {
-	unsigned long flags;
-
-	spin_lock_irqsave(&tmr->lock, flags);
+	guard(spinlock_irqsave)(&tmr->lock);
 	seq_timer_reset(tmr);
-	spin_unlock_irqrestore(&tmr->lock, flags);
 }
 
 
@@ -121,7 +115,6 @@ static void snd_seq_timer_interrupt(struct snd_timer_instance *timeri,
 				    unsigned long resolution,
 				    unsigned long ticks)
 {
-	unsigned long flags;
 	struct snd_seq_queue *q = timeri->callback_data;
 	struct snd_seq_timer *tmr;
 
@@ -130,29 +123,27 @@ static void snd_seq_timer_interrupt(struct snd_timer_instance *timeri,
 	tmr = q->timer;
 	if (tmr == NULL)
 		return;
-	spin_lock_irqsave(&tmr->lock, flags);
-	if (!tmr->running) {
-		spin_unlock_irqrestore(&tmr->lock, flags);
-		return;
-	}
 
-	resolution *= ticks;
-	if (tmr->skew != tmr->skew_base) {
-		/* FIXME: assuming skew_base = 0x10000 */
-		resolution = (resolution >> 16) * tmr->skew +
-			(((resolution & 0xffff) * tmr->skew) >> 16);
-	}
+	scoped_guard(spinlock_irqsave, &tmr->lock) {
+		if (!tmr->running)
+			return;
 
-	/* update timer */
-	snd_seq_inc_time_nsec(&tmr->cur_time, resolution);
+		resolution *= ticks;
+		if (tmr->skew != tmr->skew_base) {
+			/* FIXME: assuming skew_base = 0x10000 */
+			resolution = (resolution >> 16) * tmr->skew +
+				(((resolution & 0xffff) * tmr->skew) >> 16);
+		}
 
-	/* calculate current tick */
-	snd_seq_timer_update_tick(&tmr->tick, resolution);
+		/* update timer */
+		snd_seq_inc_time_nsec(&tmr->cur_time, resolution);
 
-	/* register actual time of this timer update */
-	ktime_get_ts64(&tmr->last_update);
+		/* calculate current tick */
+		snd_seq_timer_update_tick(&tmr->tick, resolution);
 
-	spin_unlock_irqrestore(&tmr->lock, flags);
+		/* register actual time of this timer update */
+		ktime_get_ts64(&tmr->last_update);
+	}
 
 	/* check queues and dispatch events */
 	snd_seq_check_queue(q, 1, 0);
@@ -161,18 +152,15 @@ static void snd_seq_timer_interrupt(struct snd_timer_instance *timeri,
 /* set current tempo */
 int snd_seq_timer_set_tempo(struct snd_seq_timer * tmr, int tempo)
 {
-	unsigned long flags;
-
 	if (snd_BUG_ON(!tmr))
 		return -EINVAL;
 	if (tempo <= 0)
 		return -EINVAL;
-	spin_lock_irqsave(&tmr->lock, flags);
+	guard(spinlock_irqsave)(&tmr->lock);
 	if ((unsigned int)tempo != tmr->tempo) {
 		tmr->tempo = tempo;
 		snd_seq_timer_set_tick_resolution(tmr);
 	}
-	spin_unlock_irqrestore(&tmr->lock, flags);
 	return 0;
 }
 
@@ -180,17 +168,15 @@ int snd_seq_timer_set_tempo(struct snd_seq_timer * tmr, int tempo)
 int snd_seq_timer_set_tempo_ppq(struct snd_seq_timer *tmr, int tempo, int ppq)
 {
 	int changed;
-	unsigned long flags;
 
 	if (snd_BUG_ON(!tmr))
 		return -EINVAL;
 	if (tempo <= 0 || ppq <= 0)
 		return -EINVAL;
-	spin_lock_irqsave(&tmr->lock, flags);
+	guard(spinlock_irqsave)(&tmr->lock);
 	if (tmr->running && (ppq != tmr->ppq)) {
 		/* refuse to change ppq on running timers */
 		/* because it will upset the song position (ticks) */
-		spin_unlock_irqrestore(&tmr->lock, flags);
 		pr_debug("ALSA: seq: cannot change ppq of a running timer\n");
 		return -EBUSY;
 	}
@@ -199,7 +185,6 @@ int snd_seq_timer_set_tempo_ppq(struct snd_seq_timer *tmr, int tempo, int ppq)
 	tmr->ppq = ppq;
 	if (changed)
 		snd_seq_timer_set_tick_resolution(tmr);
-	spin_unlock_irqrestore(&tmr->lock, flags);
 	return 0;
 }
 
@@ -207,15 +192,12 @@ int snd_seq_timer_set_tempo_ppq(struct snd_seq_timer *tmr, int tempo, int ppq)
 int snd_seq_timer_set_position_tick(struct snd_seq_timer *tmr,
 				    snd_seq_tick_time_t position)
 {
-	unsigned long flags;
-
 	if (snd_BUG_ON(!tmr))
 		return -EINVAL;
 
-	spin_lock_irqsave(&tmr->lock, flags);
+	guard(spinlock_irqsave)(&tmr->lock);
 	tmr->tick.cur_tick = position;
 	tmr->tick.fraction = 0;
-	spin_unlock_irqrestore(&tmr->lock, flags);
 	return 0;
 }
 
@@ -223,15 +205,12 @@ int snd_seq_timer_set_position_tick(struct snd_seq_timer *tmr,
 int snd_seq_timer_set_position_time(struct snd_seq_timer *tmr,
 				    snd_seq_real_time_t position)
 {
-	unsigned long flags;
-
 	if (snd_BUG_ON(!tmr))
 		return -EINVAL;
 
 	snd_seq_sanity_real_time(&position);
-	spin_lock_irqsave(&tmr->lock, flags);
+	guard(spinlock_irqsave)(&tmr->lock);
 	tmr->cur_time = position;
-	spin_unlock_irqrestore(&tmr->lock, flags);
 	return 0;
 }
 
@@ -239,8 +218,6 @@ int snd_seq_timer_set_position_time(struct snd_seq_timer *tmr,
 int snd_seq_timer_set_skew(struct snd_seq_timer *tmr, unsigned int skew,
 			   unsigned int base)
 {
-	unsigned long flags;
-
 	if (snd_BUG_ON(!tmr))
 		return -EINVAL;
 
@@ -249,9 +226,8 @@ int snd_seq_timer_set_skew(struct snd_seq_timer *tmr, unsigned int skew,
 		pr_debug("ALSA: seq: invalid skew base 0x%x\n", base);
 		return -EINVAL;
 	}
-	spin_lock_irqsave(&tmr->lock, flags);
+	guard(spinlock_irqsave)(&tmr->lock);
 	tmr->skew = skew;
-	spin_unlock_irqrestore(&tmr->lock, flags);
 	return 0;
 }
 
@@ -296,12 +272,12 @@ int snd_seq_timer_open(struct snd_seq_queue *q)
 		snd_timer_instance_free(t);
 		return err;
 	}
-	spin_lock_irq(&tmr->lock);
-	if (tmr->timeri)
-		err = -EBUSY;
-	else
-		tmr->timeri = t;
-	spin_unlock_irq(&tmr->lock);
+	scoped_guard(spinlock_irq, &tmr->lock) {
+		if (tmr->timeri)
+			err = -EBUSY;
+		else
+			tmr->timeri = t;
+	}
 	if (err < 0) {
 		snd_timer_close(t);
 		snd_timer_instance_free(t);
@@ -318,10 +294,10 @@ int snd_seq_timer_close(struct snd_seq_queue *q)
 	tmr = q->timer;
 	if (snd_BUG_ON(!tmr))
 		return -EINVAL;
-	spin_lock_irq(&tmr->lock);
-	t = tmr->timeri;
-	tmr->timeri = NULL;
-	spin_unlock_irq(&tmr->lock);
+	scoped_guard(spinlock_irq, &tmr->lock) {
+		t = tmr->timeri;
+		tmr->timeri = NULL;
+	}
 	if (t) {
 		snd_timer_close(t);
 		snd_timer_instance_free(t);
@@ -342,13 +318,8 @@ static int seq_timer_stop(struct snd_seq_timer *tmr)
 
 int snd_seq_timer_stop(struct snd_seq_timer *tmr)
 {
-	unsigned long flags;
-	int err;
-
-	spin_lock_irqsave(&tmr->lock, flags);
-	err = seq_timer_stop(tmr);
-	spin_unlock_irqrestore(&tmr->lock, flags);
-	return err;
+	guard(spinlock_irqsave)(&tmr->lock);
+	return seq_timer_stop(tmr);
 }
 
 static int initialize_timer(struct snd_seq_timer *tmr)
@@ -398,13 +369,8 @@ static int seq_timer_start(struct snd_seq_timer *tmr)
 
 int snd_seq_timer_start(struct snd_seq_timer *tmr)
 {
-	unsigned long flags;
-	int err;
-
-	spin_lock_irqsave(&tmr->lock, flags);
-	err = seq_timer_start(tmr);
-	spin_unlock_irqrestore(&tmr->lock, flags);
-	return err;
+	guard(spinlock_irqsave)(&tmr->lock);
+	return seq_timer_start(tmr);
 }
 
 static int seq_timer_continue(struct snd_seq_timer *tmr)
@@ -426,13 +392,8 @@ static int seq_timer_continue(struct snd_seq_timer *tmr)
 
 int snd_seq_timer_continue(struct snd_seq_timer *tmr)
 {
-	unsigned long flags;
-	int err;
-
-	spin_lock_irqsave(&tmr->lock, flags);
-	err = seq_timer_continue(tmr);
-	spin_unlock_irqrestore(&tmr->lock, flags);
-	return err;
+	guard(spinlock_irqsave)(&tmr->lock);
+	return seq_timer_continue(tmr);
 }
 
 /* return current 'real' time. use timeofday() to get better granularity. */
@@ -440,9 +401,8 @@ snd_seq_real_time_t snd_seq_timer_get_cur_time(struct snd_seq_timer *tmr,
 					       bool adjust_ktime)
 {
 	snd_seq_real_time_t cur_time;
-	unsigned long flags;
 
-	spin_lock_irqsave(&tmr->lock, flags);
+	guard(spinlock_irqsave)(&tmr->lock);
 	cur_time = tmr->cur_time;
 	if (adjust_ktime && tmr->running) {
 		struct timespec64 tm;
@@ -453,7 +413,6 @@ snd_seq_real_time_t snd_seq_timer_get_cur_time(struct snd_seq_timer *tmr,
 		cur_time.tv_sec += tm.tv_sec;
 		snd_seq_sanity_real_time(&cur_time);
 	}
-	spin_unlock_irqrestore(&tmr->lock, flags);
 	return cur_time;	
 }
 
@@ -461,13 +420,8 @@ snd_seq_real_time_t snd_seq_timer_get_cur_time(struct snd_seq_timer *tmr,
  high PPQ values) */
 snd_seq_tick_time_t snd_seq_timer_get_cur_tick(struct snd_seq_timer *tmr)
 {
-	snd_seq_tick_time_t cur_tick;
-	unsigned long flags;
-
-	spin_lock_irqsave(&tmr->lock, flags);
-	cur_tick = tmr->tick.cur_tick;
-	spin_unlock_irqrestore(&tmr->lock, flags);
-	return cur_tick;
+	guard(spinlock_irqsave)(&tmr->lock);
+	return tmr->tick.cur_tick;
 }
 
 
@@ -486,19 +440,18 @@ void snd_seq_info_timer_read(struct snd_info_entry *entry,
 		q = queueptr(idx);
 		if (q == NULL)
 			continue;
-		mutex_lock(&q->timer_mutex);
-		tmr = q->timer;
-		if (!tmr)
-			goto unlock;
-		ti = tmr->timeri;
-		if (!ti)
-			goto unlock;
-		snd_iprintf(buffer, "Timer for queue %i : %s\n", q->queue, ti->timer->name);
-		resolution = snd_timer_resolution(ti) * tmr->ticks;
-		snd_iprintf(buffer, "  Period time : %lu.%09lu\n", resolution / 1000000000, resolution % 1000000000);
-		snd_iprintf(buffer, "  Skew : %u / %u\n", tmr->skew, tmr->skew_base);
-unlock:
-		mutex_unlock(&q->timer_mutex);
+		scoped_guard(mutex, &q->timer_mutex) {
+			tmr = q->timer;
+			if (!tmr)
+				break;
+			ti = tmr->timeri;
+			if (!ti)
+				break;
+			snd_iprintf(buffer, "Timer for queue %i : %s\n", q->queue, ti->timer->name);
+			resolution = snd_timer_resolution(ti) * tmr->ticks;
+			snd_iprintf(buffer, "  Period time : %lu.%09lu\n", resolution / 1000000000, resolution % 1000000000);
+			snd_iprintf(buffer, "  Skew : %u / %u\n", tmr->skew, tmr->skew_base);
+		}
 		queuefree(q);
  	}
 }