1 files changed, 117 insertions, 41 deletions

diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 1b5c50a68e23..79c55c26eaee 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -772,6 +772,12 @@ static irqreturn_t irq_nested_primary_handler(int irq, void *dev_id)
 	return IRQ_NONE;
 }
 
+static irqreturn_t irq_forced_secondary_handler(int irq, void *dev_id)
+{
+	WARN(1, "Secondary action handler called for irq %d\n", irq);
+	return IRQ_NONE;
+}
+
 static int irq_wait_for_interrupt(struct irqaction *action)
 {
 	set_current_state(TASK_INTERRUPTIBLE);
@@ -798,7 +804,8 @@ static int irq_wait_for_interrupt(struct irqaction *action)
 static void irq_finalize_oneshot(struct irq_desc *desc,
 				 struct irqaction *action)
 {
-	if (!(desc->istate & IRQS_ONESHOT))
+	if (!(desc->istate & IRQS_ONESHOT) ||
+	    action->handler == irq_forced_secondary_handler)
 		return;
 again:
 	chip_bus_lock(desc);
@@ -960,6 +967,18 @@ static void irq_thread_dtor(struct callback_head *unused)
 	irq_finalize_oneshot(desc, action);
 }
 
+static void irq_wake_secondary(struct irq_desc *desc, struct irqaction *action)
+{
+	struct irqaction *secondary = action->secondary;
+
+	if (WARN_ON_ONCE(!secondary))
+		return;
+
+	raw_spin_lock_irq(&desc->lock);
+	__irq_wake_thread(desc, secondary);
+	raw_spin_unlock_irq(&desc->lock);
+}
+
 /*
  * Interrupt handler thread
  */
@@ -990,6 +1009,8 @@ static int irq_thread(void *data)
 		action_ret = handler_fn(desc, action);
 		if (action_ret == IRQ_HANDLED)
 			atomic_inc(&desc->threads_handled);
+		if (action_ret == IRQ_WAKE_THREAD)
+			irq_wake_secondary(desc, action);
 
 #ifdef CONFIG_PREEMPT_RT_FULL
 		migrate_disable();
@@ -1040,20 +1061,36 @@ void irq_wake_thread(unsigned int irq, void *dev_id)
 }
 EXPORT_SYMBOL_GPL(irq_wake_thread);
 
-static void irq_setup_forced_threading(struct irqaction *new)
+static int irq_setup_forced_threading(struct irqaction *new)
 {
 	if (!force_irqthreads)
-		return;
+		return 0;
 	if (new->flags & (IRQF_NO_THREAD | IRQF_PERCPU | IRQF_ONESHOT))
-		return;
+		return 0;
 
 	new->flags |= IRQF_ONESHOT;
 
-	if (!new->thread_fn) {
-		set_bit(IRQTF_FORCED_THREAD, &new->thread_flags);
-		new->thread_fn = new->handler;
-		new->handler = irq_default_primary_handler;
+	/*
+	 * Handle the case where we have a real primary handler and a
+	 * thread handler. We force thread them as well by creating a
+	 * secondary action.
+	 */
+	if (new->handler != irq_default_primary_handler && new->thread_fn) {
+		/* Allocate the secondary action */
+		new->secondary = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
+		if (!new->secondary)
+			return -ENOMEM;
+		new->secondary->handler = irq_forced_secondary_handler;
+		new->secondary->thread_fn = new->thread_fn;
+		new->secondary->dev_id = new->dev_id;
+		new->secondary->irq = new->irq;
+		new->secondary->name = new->name;
 	}
+	/* Deal with the primary handler */
+	set_bit(IRQTF_FORCED_THREAD, &new->thread_flags);
+	new->thread_fn = new->handler;
+	new->handler = irq_default_primary_handler;
+	return 0;
 }
 
 static int irq_request_resources(struct irq_desc *desc)
@@ -1073,6 +1110,48 @@ static void irq_release_resources(struct irq_desc *desc)
 		c->irq_release_resources(d);
 }
 
+static int
+setup_irq_thread(struct irqaction *new, unsigned int irq, bool secondary)
+{
+	struct task_struct *t;
+	struct sched_param param = {
+		.sched_priority = MAX_USER_RT_PRIO/2,
+	};
+
+	if (!secondary) {
+		t = kthread_create(irq_thread, new, "irq/%d-%s", irq,
+				   new->name);
+	} else {
+		t = kthread_create(irq_thread, new, "irq/%d-s-%s", irq,
+				   new->name);
+		param.sched_priority += 1;
+	}
+
+	if (IS_ERR(t))
+		return PTR_ERR(t);
+
+	sched_setscheduler_nocheck(t, SCHED_FIFO, &param);
+
+	/*
+	 * We keep the reference to the task struct even if
+	 * the thread dies to avoid that the interrupt code
+	 * references an already freed task_struct.
+	 */
+	get_task_struct(t);
+	new->thread = t;
+	/*
+	 * Tell the thread to set its affinity. This is
+	 * important for shared interrupt handlers as we do
+	 * not invoke setup_affinity() for the secondary
+	 * handlers as everything is already set up. Even for
+	 * interrupts marked with IRQF_NO_BALANCE this is
+	 * correct as we want the thread to move to the cpu(s)
+	 * on which the requesting code placed the interrupt.
+	 */
+	set_bit(IRQTF_AFFINITY, &new->thread_flags);
+	return 0;
+}
+
 /*
  * Internal function to register an irqaction - typically used to
  * allocate special interrupts that are part of the architecture.
@@ -1093,6 +1172,8 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
 	if (!try_module_get(desc->owner))
 		return -ENODEV;
 
+	new->irq = irq;
+
 	/*
 	 * Check whether the interrupt nests into another interrupt
 	 * thread.
@@ -1110,8 +1191,11 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
 		 */
 		new->handler = irq_nested_primary_handler;
 	} else {
-		if (irq_settings_can_thread(desc))
-			irq_setup_forced_threading(new);
+		if (irq_settings_can_thread(desc)) {
+			ret = irq_setup_forced_threading(new);
+			if (ret)
+				goto out_mput;
+		}
 	}
 
 	/*
@@ -1120,37 +1204,14 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
 	 * thread.
 	 */
 	if (new->thread_fn && !nested) {
-		struct task_struct *t;
-		static const struct sched_param param = {
-			.sched_priority = MAX_USER_RT_PRIO/2,
-		};
-
-		t = kthread_create(irq_thread, new, "irq/%d-%s", irq,
-				   new->name);
-		if (IS_ERR(t)) {
-			ret = PTR_ERR(t);
+		ret = setup_irq_thread(new, irq, false);
+		if (ret)
 			goto out_mput;
+		if (new->secondary) {
+			ret = setup_irq_thread(new->secondary, irq, true);
+			if (ret)
+				goto out_thread;
 		}
-
-		sched_setscheduler_nocheck(t, SCHED_FIFO, &param);
-
-		/*
-		 * We keep the reference to the task struct even if
-		 * the thread dies to avoid that the interrupt code
-		 * references an already freed task_struct.
-		 */
-		get_task_struct(t);
-		new->thread = t;
-		/*
-		 * Tell the thread to set its affinity. This is
-		 * important for shared interrupt handlers as we do
-		 * not invoke setup_affinity() for the secondary
-		 * handlers as everything is already set up. Even for
-		 * interrupts marked with IRQF_NO_BALANCE this is
-		 * correct as we want the thread to move to the cpu(s)
-		 * on which the requesting code placed the interrupt.
-		 */
-		set_bit(IRQTF_AFFINITY, &new->thread_flags);
 	}
 
 	if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
@@ -1326,7 +1387,6 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
 				   irq, nmsk, omsk);
 	}
 
-	new->irq = irq;
 	*old_ptr = new;
 
 	irq_pm_install_action(desc, new);
@@ -1352,6 +1412,8 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
 	 */
 	if (new->thread)
 		wake_up_process(new->thread);
+	if (new->secondary)
+		wake_up_process(new->secondary->thread);
 
 	register_irq_proc(irq, desc);
 	new->dir = NULL;
@@ -1382,6 +1444,13 @@ out_thread:
 		kthread_stop(t);
 		put_task_struct(t);
 	}
+	if (new->secondary && new->secondary->thread) {
+		struct task_struct *t = new->secondary->thread;
+
+		new->secondary->thread = NULL;
+		kthread_stop(t);
+		put_task_struct(t);
+	}
 out_mput:
 	module_put(desc->owner);
 	return ret;
@@ -1489,9 +1558,14 @@ static struct irqaction *__free_irq(unsigned int irq, void *dev_id)
 	if (action->thread) {
 		kthread_stop(action->thread);
 		put_task_struct(action->thread);
+		if (action->secondary && action->secondary->thread) {
+			kthread_stop(action->secondary->thread);
+			put_task_struct(action->secondary->thread);
+		}
 	}
 
 	module_put(desc->owner);
+	kfree(action->secondary);
 	return action;
 }
 
@@ -1635,8 +1709,10 @@ int request_threaded_irq(unsigned int irq, irq_handler_t handler,
 	retval = __setup_irq(irq, desc, action);
 	chip_bus_sync_unlock(desc);
 
-	if (retval)
+	if (retval) {
+		kfree(action->secondary);
 		kfree(action);
+	}
 
 #ifdef CONFIG_DEBUG_SHIRQ_FIXME
 	if (!retval && (irqflags & IRQF_SHARED)) {