genirq: Add sanity checks for PM options on shared interrupt lines

Account the IRQF_NO_SUSPEND and IRQF_RESUME_EARLY actions on shared
interrupt lines and yell loudly if there is a mismatch.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

include/linux/irqdesc.h

@@ -36,6 +36,11 @@ struct irq_desc;
  * @threads_oneshot:	bitfield to handle shared oneshot threads
  * @threads_active:	number of irqaction threads currently running
  * @wait_for_threads:	wait queue for sync_irq to wait for threaded handlers
+ * @nr_actions:		number of installed actions on this descriptor
+ * @no_suspend_depth:	number of irqactions on a irq descriptor with
+ *			IRQF_NO_SUSPEND set
+ * @force_resume_depth:	number of irqactions on a irq descriptor with
+ *			IRQF_FORCE_RESUME set
  * @dir:		/proc/irq/ procfs entry
  * @name:		flow handler name for /proc/interrupts output
  */
@@ -68,6 +73,11 @@ struct irq_desc {
 	unsigned long		threads_oneshot;
 	atomic_t		threads_active;
 	wait_queue_head_t       wait_for_threads;
+#ifdef CONFIG_PM_SLEEP
+	unsigned int		nr_actions;
+	unsigned int		no_suspend_depth;
+	unsigned int		force_resume_depth;
+#endif
 #ifdef CONFIG_PROC_FS
 	struct proc_dir_entry	*dir;
 #endif

kernel/irq/internals.h

@@ -194,3 +194,13 @@ static inline void kstat_incr_irqs_this_cpu(unsigned int irq, struct irq_desc *d
 	__this_cpu_inc(*desc->kstat_irqs);
 	__this_cpu_inc(kstat.irqs_sum);
 }
+
+#ifdef CONFIG_PM_SLEEP
+void irq_pm_install_action(struct irq_desc *desc, struct irqaction *action);
+void irq_pm_remove_action(struct irq_desc *desc, struct irqaction *action);
+#else
+static inline void
+irq_pm_install_action(struct irq_desc *desc, struct irqaction *action) { }
+static inline void
+irq_pm_remove_action(struct irq_desc *desc, struct irqaction *action) { }
+#endif

kernel/irq/manage.c

@@ -1200,6 +1200,8 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
 	new->irq = irq;
 	*old_ptr = new;
 
+	irq_pm_install_action(desc, new);
+
 	/* Reset broken irq detection when installing new handler */
 	desc->irq_count = 0;
 	desc->irqs_unhandled = 0;
@@ -1318,6 +1320,8 @@ static struct irqaction *__free_irq(unsigned int irq, void *dev_id)
 	/* Found it - now remove it from the list of entries: */
 	*action_ptr = action->next;
 
+	irq_pm_remove_action(desc, action);
+
 	/* If this was the last handler, shut down the IRQ line: */
 	if (!desc->action) {
 		irq_shutdown(desc);

kernel/irq/pm.c

@@ -13,6 +13,42 @@
 
 #include "internals.h"
 
+/*
+ * Called from __setup_irq() with desc->lock held after @action has
+ * been installed in the action chain.
+ */
+void irq_pm_install_action(struct irq_desc *desc, struct irqaction *action)
+{
+	desc->nr_actions++;
+
+	if (action->flags & IRQF_FORCE_RESUME)
+		desc->force_resume_depth++;
+
+	WARN_ON_ONCE(desc->force_resume_depth &&
+		     desc->force_resume_depth != desc->nr_actions);
+
+	if (action->flags & IRQF_NO_SUSPEND)
+		desc->no_suspend_depth++;
+
+	WARN_ON_ONCE(desc->no_suspend_depth &&
+		     desc->no_suspend_depth != desc->nr_actions);
+}
+
+/*
+ * Called from __free_irq() with desc->lock held after @action has
+ * been removed from the action chain.
+ */
+void irq_pm_remove_action(struct irq_desc *desc, struct irqaction *action)
+{
+	desc->nr_actions--;
+
+	if (action->flags & IRQF_FORCE_RESUME)
+		desc->force_resume_depth--;
+
+	if (action->flags & IRQF_NO_SUSPEND)
+		desc->no_suspend_depth--;
+}
+
 static void suspend_device_irq(struct irq_desc *desc, int irq)
 {
 	if (!desc->action || (desc->action->flags & IRQF_NO_SUSPEND))