On Tue, 13 Jan 2015 11:38:14 +0100 (CET)
Thomas Gleixner [off-list ref] wrote:

quoted

+/**
+ *	handle_dumb_demux_irq - Dumb demuxer irq handle function.
+ *	@irq:	the interrupt number
+ *	@desc:	the interrupt description structure for this irq
+ *
+ *	Dumb demux interrupts are sent from a demultiplexing interrupt handler
+ *	which is not able to decide which child interrupt interrupt handler
+ *	should be called.
+ *
+ *	Note: The caller is expected to handle the ack, clear, mask and
+ *	unmask issues if necessary.
+ */
+irqreturn_t
+handle_dumb_demux_irq(unsigned int irq, struct irq_desc *desc)
+{
+	irqreturn_t retval = IRQ_NONE;
+
+	raw_spin_lock(&desc->lock);
+
+	if (!irq_may_run(desc))
+		goto out_unlock;
+
+	desc->istate &= ~(IRQS_REPLAY | IRQS_WAITING);
+	kstat_incr_irqs_this_cpu(irq, desc);
+
+	if (unlikely(!desc->action || irqd_irq_disabled(&desc->irq_data))) {
+		desc->istate |= IRQS_PENDING;
+		goto out_unlock;
+	}
+
+	retval = handle_irq_event_no_spurious_check(desc);
+
+out_unlock:
+	raw_spin_unlock(&desc->lock);
+
+	return retval;
+}
+EXPORT_SYMBOL_GPL(handle_dumb_demux_irq);

This should go into the new file as well, so it gets compiled out when
not enabled.

Actually, I can't move that function out of kernel/irq/chip.c because
it calls irq_may_run which is statically defined in this file.
Should I export this function or just enclose it in a
#ifdef DUMB_IRQ_DEMUX section ?


-- 
Boris Brezillon, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com