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>

4 files changed, 60 insertions, 0 deletions

diff --git a/include/linux/irqdesc.h b/include/linux/irqdesc.h
index 472c021a2d4f..cb1a31e448ae 100644
--- a/include/linux/irqdesc.h
+++ b/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
diff --git a/kernel/irq/internals.h b/kernel/irq/internals.h
index af2821178900..c402502a5111 100644
--- a/kernel/irq/internals.h
+++ b/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
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index fa564e8db996..0a9104b4608b 100644
--- a/kernel/irq/manage.c
+++ b/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);
diff --git a/kernel/irq/pm.c b/kernel/irq/pm.c
index b84141dcee5e..1b1b67a73218 100644
--- a/kernel/irq/pm.c
+++ b/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))