Merge branches 'irq-urgent-for-linus' and 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

torvalds · torvalds · commit 511601bdbcac · 2015-11-15T09:30:48.000-08:00
Pull irq and timer fixes from Thomas Gleixner:

 - An irq regression fix to restore the wakeup behaviour of chained
   interrupts.

 - A timer fix for a long standing race versus timers scheduled on a
   target cpu which got exposed by recent changes in the workqueue
   implementation.

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  genirq/PM: Restore system wake up from chained interrupts

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  timers: Use proper base migration in add_timer_on()
diff --git a/kernel/irq/internals.h b/kernel/irq/internals.h
@@ -199,6 +199,11 @@ static inline int irq_desc_get_node(struct irq_desc *desc)
 	return irq_common_data_get_node(&desc->irq_common_data);
 }
 
+static inline int irq_desc_is_chained(struct irq_desc *desc)
+{
+	return (desc->action && desc->action == &chained_action);
+}
+
 #ifdef CONFIG_PM_SLEEP
 bool irq_pm_check_wakeup(struct irq_desc *desc);
 void irq_pm_install_action(struct irq_desc *desc, struct irqaction *action);
diff --git a/kernel/irq/pm.c b/kernel/irq/pm.c
@@ -70,7 +70,8 @@ void irq_pm_remove_action(struct irq_desc *desc, struct irqaction *action)
 
 static bool suspend_device_irq(struct irq_desc *desc)
 {
-	if (!desc->action || desc->no_suspend_depth)
+	if (!desc->action || irq_desc_is_chained(desc) ||
+	    desc->no_suspend_depth)
 		return false;
 
 	if (irqd_is_wakeup_set(&desc->irq_data)) {
diff --git a/kernel/irq/proc.c b/kernel/irq/proc.c
@@ -475,7 +475,7 @@ int show_interrupts(struct seq_file *p, void *v)
 	for_each_online_cpu(j)
 		any_count |= kstat_irqs_cpu(i, j);
 	action = desc->action;
-	if ((!action || action == &chained_action) && !any_count)
+	if ((!action || irq_desc_is_chained(desc)) && !any_count)
 		goto out;
 
 	seq_printf(p, "%*d: ", prec, i);
diff --git a/kernel/time/timer.c b/kernel/time/timer.c
@@ -977,13 +977,29 @@ EXPORT_SYMBOL(add_timer);
  */
 void add_timer_on(struct timer_list *timer, int cpu)
 {
-	struct tvec_base *base = per_cpu_ptr(&tvec_bases, cpu);
+	struct tvec_base *new_base = per_cpu_ptr(&tvec_bases, cpu);
+	struct tvec_base *base;
 	unsigned long flags;
 
 	timer_stats_timer_set_start_info(timer);
 	BUG_ON(timer_pending(timer) || !timer->function);
-	spin_lock_irqsave(&base->lock, flags);
-	timer->flags = (timer->flags & ~TIMER_BASEMASK) | cpu;
+
+	/*
+	 * If @timer was on a different CPU, it should be migrated with the
+	 * old base locked to prevent other operations proceeding with the
+	 * wrong base locked.  See lock_timer_base().
+	 */
+	base = lock_timer_base(timer, &flags);
+	if (base != new_base) {
+		timer->flags |= TIMER_MIGRATING;
+
+		spin_unlock(&base->lock);
+		base = new_base;
+		spin_lock(&base->lock);
+		WRITE_ONCE(timer->flags,
+			   (timer->flags & ~TIMER_BASEMASK) | cpu);
+	}
+
 	debug_activate(timer, timer->expires);
 	internal_add_timer(base, timer);
 	spin_unlock_irqrestore(&base->lock, flags);

Original file line number	Diff line number	Diff line change
`@@ -70,7 +70,8 @@ void irq_pm_remove_action(struct irq_desc desc, struct irqaction action)`
`70`	`70`
`71`	`71`	`static bool suspend_device_irq(struct irq_desc *desc)`
`72`	`72`	`{`
`73`		`- if (!desc->action \|\| desc->no_suspend_depth)`
	`73`	`+ if (!desc->action \|\| irq_desc_is_chained(desc) \|\|`
	`74`	`+ desc->no_suspend_depth)`
`74`	`75`	`return false;`
`75`	`76`
`76`	`77`	`if (irqd_is_wakeup_set(&desc->irq_data)) {`