ns9xxx: make use of the chip's irq priorisation

The irq controller automatically masks the current and all lower prioritised
tasks until the current irq is acked.

Signed-off-by: Uwe Kleine-König <Uwe.Kleine-Koenig@digi.com>

1 files changed, 39 insertions, 1 deletions

diff --git a/arch/arm/mach-ns9xxx/irq.c b/arch/arm/mach-ns9xxx/irq.c
index d4a583cc44c5..7ddc8fde7748 100644
--- a/arch/arm/mach-ns9xxx/irq.c
+++ b/arch/arm/mach-ns9xxx/irq.c
@@ -9,6 +9,7 @@
  * the Free Software Foundation.
  */
 #include <linux/interrupt.h>
+#include <linux/kernel_stat.h>
 #include <asm/io.h>
 #include <asm/mach/irq.h>
 #include <asm/mach-types.h>
@@ -52,6 +53,43 @@ static struct irq_chip ns9xxx_chip = {
         .unmask         = ns9xxx_unmask_irq,
 };
 
+#if 0
+#define handle_irq handle_level_irq
+#else
+void handle_prio_irq(unsigned int irq, struct irq_desc *desc)
+{
+        unsigned int cpu = smp_processor_id();
+        struct irqaction *action;
+        irqreturn_t action_ret;
+
+        spin_lock(&desc->lock);
+
+        if (unlikely(desc->status & IRQ_INPROGRESS))
+                goto out_unlock;
+
+        desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
+        kstat_cpu(cpu).irqs[irq]++;
+
+        action = desc->action;
+        if (unlikely(!action || (desc->status & IRQ_DISABLED)))
+                goto out_unlock;
+
+        desc->status |= IRQ_INPROGRESS;
+        spin_unlock(&desc->lock);
+
+        action_ret = handle_IRQ_event(irq, action);
+
+        spin_lock(&desc->lock);
+        desc->status &= ~IRQ_INPROGRESS;
+        if (!(desc->status & IRQ_DISABLED) && desc->chip->ack)
+                desc->chip->ack(irq);
+
+out_unlock:
+        spin_unlock(&desc->lock);
+}
+#define handle_irq handle_prio_irq
+#endif
+
 void __init ns9xxx_init_irq(void)
 {
         int i;
@@ -69,7 +107,7 @@ void __init ns9xxx_init_irq(void)
 
         for (i = 0; i <= 31; ++i) {
                 set_irq_chip(i, &ns9xxx_chip);
-                set_irq_handler(i, handle_level_irq);
+                set_irq_handler(i, handle_irq);
                 set_irq_flags(i, IRQF_VALID);
         }
 }