irq: support domains with non-zero hwirq base

Interrupt controllers can have non-zero starting value for h/w irq numbers.
Adding support in irq_domain allows the domain hwirq numbering to match
the interrupt controllers' numbering.

As this makes looping over irqs for a domain more complicated, add loop
iterators to iterate over all hwirqs and irqs for a domain.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Reviewed-by: Jamie Iles <jamie@jamieiles.com>
Tested-by: Thomas Abraham <thomas.abraham@linaro.org>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
index b57a377..200ce83 100644
--- a/kernel/irq/irqdomain.c
+++ b/kernel/irq/irqdomain.c
@@ -20,15 +20,15 @@
 void irq_domain_add(struct irq_domain *domain)
 {
 	struct irq_data *d;
-	int hwirq;
+	int hwirq, irq;
 
 	/*
 	 * This assumes that the irq_domain owner has already allocated
 	 * the irq_descs.  This block will be removed when support for dynamic
 	 * allocation of irq_descs is added to irq_domain.
 	 */
-	for (hwirq = 0; hwirq < domain->nr_irq; hwirq++) {
-		d = irq_get_irq_data(irq_domain_to_irq(domain, hwirq));
+	irq_domain_for_each_irq(domain, hwirq, irq) {
+		d = irq_get_irq_data(irq);
 		if (!d) {
 			WARN(1, "error: assigning domain to non existant irq_desc");
 			return;
@@ -54,15 +54,15 @@
 void irq_domain_del(struct irq_domain *domain)
 {
 	struct irq_data *d;
-	int hwirq;
+	int hwirq, irq;
 
 	mutex_lock(&irq_domain_mutex);
 	list_del(&domain->list);
 	mutex_unlock(&irq_domain_mutex);
 
 	/* Clear the irq_domain assignments */
-	for (hwirq = 0; hwirq < domain->nr_irq; hwirq++) {
-		d = irq_get_irq_data(irq_domain_to_irq(domain, hwirq));
+	irq_domain_for_each_irq(domain, hwirq, irq) {
+		d = irq_get_irq_data(irq);
 		d->domain = NULL;
 	}
 }