[patch V2 12/45] genirq/chip: Rework handle_nested_irq()

Thomas Gleixner posted 45 patches 7 months, 3 weeks ago
[patch V2 12/45] genirq/chip: Rework handle_nested_irq()
Posted by Thomas Gleixner 7 months, 3 weeks ago
Use the new helpers to decide whether the interrupt should be handled and
switch the descriptor locking to guard().

Fixup the kernel doc comment while at it.

No functional change.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

---
 kernel/irq/chip.c |   78 ++++++++++++++++++++++++------------------------------
 1 file changed, 36 insertions(+), 42 deletions(-)

--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -450,48 +450,6 @@ void unmask_threaded_irq(struct irq_desc
 	unmask_irq(desc);
 }
 
-/*
- *	handle_nested_irq - Handle a nested irq from a irq thread
- *	@irq:	the interrupt number
- *
- *	Handle interrupts which are nested into a threaded interrupt
- *	handler. The handler function is called inside the calling
- *	threads context.
- */
-void handle_nested_irq(unsigned int irq)
-{
-	struct irq_desc *desc = irq_to_desc(irq);
-	struct irqaction *action;
-	irqreturn_t action_ret;
-
-	might_sleep();
-
-	raw_spin_lock_irq(&desc->lock);
-
-	desc->istate &= ~(IRQS_REPLAY | IRQS_WAITING);
-
-	action = desc->action;
-	if (unlikely(!action || irqd_irq_disabled(&desc->irq_data))) {
-		desc->istate |= IRQS_PENDING;
-		raw_spin_unlock_irq(&desc->lock);
-		return;
-	}
-
-	kstat_incr_irqs_this_cpu(desc);
-	atomic_inc(&desc->threads_active);
-	raw_spin_unlock_irq(&desc->lock);
-
-	action_ret = IRQ_NONE;
-	for_each_action_of_desc(desc, action)
-		action_ret |= action->thread_fn(action->irq, action->dev_id);
-
-	if (!irq_settings_no_debug(desc))
-		note_interrupt(desc, action_ret);
-
-	wake_threads_waitq(desc);
-}
-EXPORT_SYMBOL_GPL(handle_nested_irq);
-
 static bool irq_check_poll(struct irq_desc *desc)
 {
 	if (!(desc->istate & IRQS_POLL_INPROGRESS))
@@ -544,6 +502,42 @@ static inline bool irq_can_handle(struct
 }
 
 /**
+ * handle_nested_irq - Handle a nested irq from a irq thread
+ * @irq:	the interrupt number
+ *
+ * Handle interrupts which are nested into a threaded interrupt
+ * handler. The handler function is called inside the calling threads
+ * context.
+ */
+void handle_nested_irq(unsigned int irq)
+{
+	struct irq_desc *desc = irq_to_desc(irq);
+	struct irqaction *action;
+	irqreturn_t action_ret;
+
+	might_sleep();
+
+	scoped_guard(raw_spinlock_irq, &desc->lock) {
+		if (irq_can_handle_actions(desc))
+			return;
+
+		action = desc->action;
+		kstat_incr_irqs_this_cpu(desc);
+		atomic_inc(&desc->threads_active);
+	}
+
+	action_ret = IRQ_NONE;
+	for_each_action_of_desc(desc, action)
+		action_ret |= action->thread_fn(action->irq, action->dev_id);
+
+	if (!irq_settings_no_debug(desc))
+		note_interrupt(desc, action_ret);
+
+	wake_threads_waitq(desc);
+}
+EXPORT_SYMBOL_GPL(handle_nested_irq);
+
+/**
  *	handle_simple_irq - Simple and software-decoded IRQs.
  *	@desc:	the interrupt description structure for this irq
  *
Re: [patch V2 12/45] genirq/chip: Rework handle_nested_irq()
Posted by Marek Szyprowski 7 months, 1 week ago
On 29.04.2025 08:55, Thomas Gleixner wrote:
> Use the new helpers to decide whether the interrupt should be handled and
> switch the descriptor locking to guard().
>
> Fixup the kernel doc comment while at it.
>
> No functional change.
>
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
>
> ---
>   kernel/irq/chip.c |   78 ++++++++++++++++++++++++------------------------------
>   1 file changed, 36 insertions(+), 42 deletions(-)
>
> --- a/kernel/irq/chip.c
> +++ b/kernel/irq/chip.c
> @@ -450,48 +450,6 @@ void unmask_threaded_irq(struct irq_desc
>   	unmask_irq(desc);
>   }
>   
> -/*
> - *	handle_nested_irq - Handle a nested irq from a irq thread
> - *	@irq:	the interrupt number
> - *
> - *	Handle interrupts which are nested into a threaded interrupt
> - *	handler. The handler function is called inside the calling
> - *	threads context.
> - */
> -void handle_nested_irq(unsigned int irq)
> -{
> -	struct irq_desc *desc = irq_to_desc(irq);
> -	struct irqaction *action;
> -	irqreturn_t action_ret;
> -
> -	might_sleep();
> -
> -	raw_spin_lock_irq(&desc->lock);
> -
> -	desc->istate &= ~(IRQS_REPLAY | IRQS_WAITING);
> -
> -	action = desc->action;
> -	if (unlikely(!action || irqd_irq_disabled(&desc->irq_data))) {
> -		desc->istate |= IRQS_PENDING;
> -		raw_spin_unlock_irq(&desc->lock);
> -		return;
> -	}
> -
> -	kstat_incr_irqs_this_cpu(desc);
> -	atomic_inc(&desc->threads_active);
> -	raw_spin_unlock_irq(&desc->lock);
> -
> -	action_ret = IRQ_NONE;
> -	for_each_action_of_desc(desc, action)
> -		action_ret |= action->thread_fn(action->irq, action->dev_id);
> -
> -	if (!irq_settings_no_debug(desc))
> -		note_interrupt(desc, action_ret);
> -
> -	wake_threads_waitq(desc);
> -}
> -EXPORT_SYMBOL_GPL(handle_nested_irq);
> -
>   static bool irq_check_poll(struct irq_desc *desc)
>   {
>   	if (!(desc->istate & IRQS_POLL_INPROGRESS))
> @@ -544,6 +502,42 @@ static inline bool irq_can_handle(struct
>   }
>   
>   /**
> + * handle_nested_irq - Handle a nested irq from a irq thread
> + * @irq:	the interrupt number
> + *
> + * Handle interrupts which are nested into a threaded interrupt
> + * handler. The handler function is called inside the calling threads
> + * context.
> + */
> +void handle_nested_irq(unsigned int irq)
> +{
> +	struct irq_desc *desc = irq_to_desc(irq);
> +	struct irqaction *action;
> +	irqreturn_t action_ret;
> +
> +	might_sleep();
> +
> +	scoped_guard(raw_spinlock_irq, &desc->lock) {
> +		if (irq_can_handle_actions(desc))

This should be "if (!irq_can_handle_actions(desc))" to fix nested irqs handling in today's linux-next.


> +			return;
> +
> +		action = desc->action;
> +		kstat_incr_irqs_this_cpu(desc);
> +		atomic_inc(&desc->threads_active);
> +	}
> +
> +	action_ret = IRQ_NONE;
> +	for_each_action_of_desc(desc, action)
> +		action_ret |= action->thread_fn(action->irq, action->dev_id);
> +
> +	if (!irq_settings_no_debug(desc))
> +		note_interrupt(desc, action_ret);
> +
> +	wake_threads_waitq(desc);
> +}
> +EXPORT_SYMBOL_GPL(handle_nested_irq);
> +
> +/**
>    *	handle_simple_irq - Simple and software-decoded IRQs.
>    *	@desc:	the interrupt description structure for this irq
>    *
>
>
>
>
Best regards
-- 
Marek Szyprowski, PhD
Samsung R&D Institute Poland
Re: [patch V2 12/45] genirq/chip: Rework handle_nested_irq()
Posted by Thomas Gleixner 7 months, 1 week ago
On Thu, May 08 2025 at 22:56, Marek Szyprowski wrote:
> On 29.04.2025 08:55, Thomas Gleixner wrote:
>> +void handle_nested_irq(unsigned int irq)
>> +{
>> +	struct irq_desc *desc = irq_to_desc(irq);
>> +	struct irqaction *action;
>> +	irqreturn_t action_ret;
>> +
>> +	might_sleep();
>> +
>> +	scoped_guard(raw_spinlock_irq, &desc->lock) {
>> +		if (irq_can_handle_actions(desc))
>
> This should be "if (!irq_can_handle_actions(desc))" to fix nested irqs handling in today's linux-next.

Ooops.
[tip: irq/core] genirq/chip: Rework handle_nested_irq()
Posted by tip-bot2 for Thomas Gleixner 7 months, 2 weeks ago
The following commit has been merged into the irq/core branch of tip:

Commit-ID:     2ef2e13094c7510c40833951c2ec36cf8574331a
Gitweb:        https://git.kernel.org/tip/2ef2e13094c7510c40833951c2ec36cf8574331a
Author:        Thomas Gleixner <tglx@linutronix.de>
AuthorDate:    Tue, 29 Apr 2025 08:55:05 +02:00
Committer:     Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Wed, 07 May 2025 09:08:12 +02:00

genirq/chip: Rework handle_nested_irq()

Use the new helpers to decide whether the interrupt should be handled and
switch the descriptor locking to guard().

Fixup the kernel doc comment while at it.

No functional change.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/all/20250429065420.744042890@linutronix.de


---
 kernel/irq/chip.c | 78 +++++++++++++++++++++-------------------------
 1 file changed, 36 insertions(+), 42 deletions(-)

diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index 4b4ce38..87add4b 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -450,48 +450,6 @@ void unmask_threaded_irq(struct irq_desc *desc)
 	unmask_irq(desc);
 }
 
-/*
- *	handle_nested_irq - Handle a nested irq from a irq thread
- *	@irq:	the interrupt number
- *
- *	Handle interrupts which are nested into a threaded interrupt
- *	handler. The handler function is called inside the calling
- *	threads context.
- */
-void handle_nested_irq(unsigned int irq)
-{
-	struct irq_desc *desc = irq_to_desc(irq);
-	struct irqaction *action;
-	irqreturn_t action_ret;
-
-	might_sleep();
-
-	raw_spin_lock_irq(&desc->lock);
-
-	desc->istate &= ~(IRQS_REPLAY | IRQS_WAITING);
-
-	action = desc->action;
-	if (unlikely(!action || irqd_irq_disabled(&desc->irq_data))) {
-		desc->istate |= IRQS_PENDING;
-		raw_spin_unlock_irq(&desc->lock);
-		return;
-	}
-
-	kstat_incr_irqs_this_cpu(desc);
-	atomic_inc(&desc->threads_active);
-	raw_spin_unlock_irq(&desc->lock);
-
-	action_ret = IRQ_NONE;
-	for_each_action_of_desc(desc, action)
-		action_ret |= action->thread_fn(action->irq, action->dev_id);
-
-	if (!irq_settings_no_debug(desc))
-		note_interrupt(desc, action_ret);
-
-	wake_threads_waitq(desc);
-}
-EXPORT_SYMBOL_GPL(handle_nested_irq);
-
 static bool irq_check_poll(struct irq_desc *desc)
 {
 	if (!(desc->istate & IRQS_POLL_INPROGRESS))
@@ -544,6 +502,42 @@ static inline bool irq_can_handle(struct irq_desc *desc)
 }
 
 /**
+ * handle_nested_irq - Handle a nested irq from a irq thread
+ * @irq:	the interrupt number
+ *
+ * Handle interrupts which are nested into a threaded interrupt
+ * handler. The handler function is called inside the calling threads
+ * context.
+ */
+void handle_nested_irq(unsigned int irq)
+{
+	struct irq_desc *desc = irq_to_desc(irq);
+	struct irqaction *action;
+	irqreturn_t action_ret;
+
+	might_sleep();
+
+	scoped_guard(raw_spinlock_irq, &desc->lock) {
+		if (irq_can_handle_actions(desc))
+			return;
+
+		action = desc->action;
+		kstat_incr_irqs_this_cpu(desc);
+		atomic_inc(&desc->threads_active);
+	}
+
+	action_ret = IRQ_NONE;
+	for_each_action_of_desc(desc, action)
+		action_ret |= action->thread_fn(action->irq, action->dev_id);
+
+	if (!irq_settings_no_debug(desc))
+		note_interrupt(desc, action_ret);
+
+	wake_threads_waitq(desc);
+}
+EXPORT_SYMBOL_GPL(handle_nested_irq);
+
+/**
  *	handle_simple_irq - Simple and software-decoded IRQs.
  *	@desc:	the interrupt description structure for this irq
  *