[PATCH] genirq: Add a IRQF_NO_DEBUG flag

[Thomas Gleixner]

The whole call to note_interrupt() can be avoided or return early when
interrupts would be marked accordingly. For IPI handlers which always
return HANDLED the whole procedure is pretty pointless to begin with.

Add a IRQF_NO_DEBUG flag.

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Cédric Le Goater <clg@xxxxxxxx>
---
 include/linux/interrupt.h |  3 +++
 include/linux/irq.h       |  2 ++
 kernel/irq/settings.h     | 12 ++++++++++++
 kernel/irq/chip.c         |  2 +-
 kernel/irq/handle.c       |  2 +-
 kernel/irq/manage.c       |  5 +++++
 6 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
index 4777850a6dc7..a52109c3f3a4 100644
--- a/include/linux/interrupt.h
+++ b/include/linux/interrupt.h
@@ -64,6 +64,8 @@
  * IRQF_NO_AUTOEN - Don't enable IRQ or NMI automatically when users request it.
  *                Users will enable it explicitly by enable_irq() or enable_nmi()
  *                later.
+ * IRQF_NO_DEBUG - Exclude from runnaway detection for IPI and similar handlers,
+ *		   depends on IRQF_PERCPU.
  */
 #define IRQF_SHARED		0x00000080
 #define IRQF_PROBE_SHARED	0x00000100
@@ -78,6 +80,7 @@
 #define IRQF_EARLY_RESUME	0x00020000
 #define IRQF_COND_SUSPEND	0x00040000
 #define IRQF_NO_AUTOEN		0x00080000
+#define IRQF_NO_DEBUG		0x00100000
 
 #define IRQF_TIMER		(__IRQF_TIMER | IRQF_NO_SUSPEND | IRQF_NO_THREAD)
 
diff --git a/include/linux/irq.h b/include/linux/irq.h
index 31b347c9f8dd..8e9a9ae471a6 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -72,6 +72,7 @@ enum irqchip_irq_state;
  *				  mechanism and from core side polling.
  * IRQ_DISABLE_UNLAZY		- Disable lazy irq disable
  * IRQ_HIDDEN			- Don't show up in /proc/interrupts
+ * IRQ_NO_DEBUG			- Exclude from note_interrupt() debugging
  */
 enum {
 	IRQ_TYPE_NONE		= 0x00000000,
@@ -99,6 +100,7 @@ enum {
 	IRQ_IS_POLLED		= (1 << 18),
 	IRQ_DISABLE_UNLAZY	= (1 << 19),
 	IRQ_HIDDEN		= (1 << 20),
+	IRQ_NO_DEBUG		= (1 << 21),
 };
 
 #define IRQF_MODIFY_MASK	\
diff --git a/kernel/irq/settings.h b/kernel/irq/settings.h
index 403378b9947b..7b7efb1a114b 100644
--- a/kernel/irq/settings.h
+++ b/kernel/irq/settings.h
@@ -18,6 +18,7 @@ enum {
 	_IRQ_IS_POLLED		= IRQ_IS_POLLED,
 	_IRQ_DISABLE_UNLAZY	= IRQ_DISABLE_UNLAZY,
 	_IRQ_HIDDEN		= IRQ_HIDDEN,
+	_IRQ_NO_DEBUG		= IRQ_NO_DEBUG,
 	_IRQF_MODIFY_MASK	= IRQF_MODIFY_MASK,
 };
 
@@ -33,6 +34,7 @@ enum {
 #define IRQ_IS_POLLED		GOT_YOU_MORON
 #define IRQ_DISABLE_UNLAZY	GOT_YOU_MORON
 #define IRQ_HIDDEN		GOT_YOU_MORON
+#define IRQ_NO_DEBUG		GOT_YOU_MORON
 #undef IRQF_MODIFY_MASK
 #define IRQF_MODIFY_MASK	GOT_YOU_MORON
 
@@ -174,3 +176,13 @@ static inline bool irq_settings_is_hidden(struct irq_desc *desc)
 {
 	return desc->status_use_accessors & _IRQ_HIDDEN;
 }
+
+static inline void irq_settings_set_no_debug(struct irq_desc *desc)
+{
+	desc->status_use_accessors |= _IRQ_NO_DEBUG;
+}
+
+static inline bool irq_settings_no_debug(struct irq_desc *desc)
+{
+	return desc->status_use_accessors & _IRQ_NO_DEBUG;
+}
diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index 8cc8e5713287..7f04c7d8296e 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -481,7 +481,7 @@ void handle_nested_irq(unsigned int irq)
 	for_each_action_of_desc(desc, action)
 		action_ret |= action->thread_fn(action->irq, action->dev_id);
 
-	if (!noirqdebug)
+	if (!irq_settings_no_debug(desc))
 		note_interrupt(desc, action_ret);
 
 	raw_spin_lock_irq(&desc->lock);
diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c
index 762a928e18f9..221d80c31e94 100644
--- a/kernel/irq/handle.c
+++ b/kernel/irq/handle.c
@@ -197,7 +197,7 @@ irqreturn_t handle_irq_event_percpu(struct irq_desc *desc)
 
 	add_interrupt_randomness(desc->irq_data.irq, flags);
 
-	if (!noirqdebug)
+	if (!irq_settings_no_debug(desc))
 		note_interrupt(desc, retval);
 	return retval;
 }
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 4c14356543d9..7bdd09e7d5f0 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -1686,8 +1686,13 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
 		if (new->flags & IRQF_PERCPU) {
 			irqd_set(&desc->irq_data, IRQD_PER_CPU);
 			irq_settings_set_per_cpu(desc);
+			if (new->flags & IRQF_NO_DEBUG)
+				irq_settings_set_no_debug(desc);
 		}
 
+		if (noirqdebug)
+			irq_settings_set_no_debug(desc);
+
 		if (new->flags & IRQF_ONESHOT)
 			desc->istate |= IRQS_ONESHOT;
 
-- 
2.31.1