diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
index be7e75c945e97b07d5f248ded5c1e0d9240756ad..ad16809c85961e16ebc804280e4a78d66cf77634 100644
--- a/include/linux/interrupt.h
+++ b/include/linux/interrupt.h
@@ -102,6 +102,7 @@ typedef irqreturn_t (*irq_handler_t)(int, void *);
* @flags: flags (see IRQF_* above)
* @thread_fn: interrupt handler function for threaded interrupts
* @thread: thread pointer for threaded interrupts
+ * @secondary: pointer to secondary irqaction (force threading)
* @thread_flags: flags related to @thread
* @thread_mask: bitmask for keeping track of @thread activity
* @dir: pointer to the proc/irq/NN/name entry
@@ -113,6 +114,7 @@ struct irqaction {
struct irqaction *next;
irq_handler_t thread_fn;
struct task_struct *thread;
+ struct irqaction *secondary;
unsigned int irq;
unsigned int flags;
unsigned long thread_flags;
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index f9a59f6cabd2d3a96f8cd9bee179b6ab4214b83e..0a63c2b20bdd00d5e7e34a865286bea49668b6f4 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -730,6 +730,12 @@ 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);
@@ -756,7 +762,8 @@ 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);
@@ -910,6 +917,18 @@ 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
*/
@@ -940,6 +959,8 @@ 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);
wake_threads_waitq(desc);
}
@@ -984,20 +1005,36 @@ 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)
@@ -1017,6 +1054,48 @@ 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, ¶m);
+
+ /*
+ * 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.
@@ -1037,6 +1116,8 @@ __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.
@@ -1054,8 +1135,11 @@ __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;
+ }
}
/*
@@ -1064,37 +1148,14 @@ __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, ¶m);
-
- /*
- * 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)) {
@@ -1267,7 +1328,6 @@ __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);
@@ -1293,6 +1353,8 @@ __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;
@@ -1323,6 +1385,13 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
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;
@@ -1430,9 +1499,14 @@ 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;
}
@@ -1576,8 +1650,10 @@ 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)) {