[tip: irq/core] genirq/chip: Rework handle_nested_irq()

tip-bot2 for Thomas Gleixner
2025-05-07T09:07:43Z

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
*