genirq: Add a IRQF_NO_DEBUG flag

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 and mark the interrupt accordingly if supplied
when the interrupt is requested.

When noirqdebug is set on the kernel commandline, then the interrupt is
marked unconditionally so that there is only one condition in the hotpath
to evaluate.

 [ clg: Add changelog ]

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/7a8ad02f-63a8-c1aa-fdd1-39d973593d02@kaod.org

1 files changed, 12 insertions, 0 deletions

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;
+}