genirq: Add preflow handler support

sparc64 needs to call a preflow handler on certain interrupts befor
calling the action chain. Integrate it into handle_fasteoi_irq. Must
be enabled via CONFIG_IRQ_FASTEOI_PREFLOW. No impact when disabled.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: David S. Miller <davem@davemloft.net>

1 files changed, 14 insertions, 0 deletions

diff --git a/include/linux/irqdesc.h b/include/linux/irqdesc.h
index 36c95f08023d..2f87d6441302 100644
--- a/include/linux/irqdesc.h
+++ b/include/linux/irqdesc.h
@@ -63,6 +63,9 @@ struct irq_desc {
         struct timer_rand_state *timer_rand_state;
         unsigned int __percpu   *kstat_irqs;
         irq_flow_handler_t      handle_irq;
+#ifdef CONFIG_IRQ_PREFLOW_FASTEOI
+        irq_preflow_handler_t   preflow_handler;
+#endif
         struct irqaction        *action;        /* IRQ action list */
 #ifdef CONFIG_GENERIC_HARDIRQS_NO_COMPAT
         unsigned int            status_use_accessors;
@@ -187,6 +190,17 @@ static inline void __set_irq_handler_unlocked(int irq,
         desc = irq_to_desc(irq);
         desc->handle_irq = handler;
 }
+
+#ifdef CONFIG_IRQ_PREFLOW_FASTEOI
+static inline void
+__irq_set_preflow_handler(unsigned int irq, irq_preflow_handler_t handler)
+{
+        struct irq_desc *desc;
+
+        desc = irq_to_desc(irq);
+        desc->preflow_handler = handler;
+}
+#endif
 #endif
 
 #endif