irqdomain: Always update revmap when setting up a virq

At irq_setup_virq() time all of the data needed to update the reverse
map is available, but the current code ignores it and relies upon the
slow path to insert revmap records.  This patch adds revmap updating
to the setup path so the slow path will no longer be necessary.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Rob Herring <rob.herring@calxeda.com>

kernel/irq/irqdomain.c

@@ -424,6 +424,18 @@ static int irq_setup_virq(struct irq_domain *domain, unsigned int virq,
 		return -1;
 	}
 
+	switch (domain->revmap_type) {
+	case IRQ_DOMAIN_MAP_LINEAR:
+		if (hwirq < domain->revmap_data.linear.size)
+			domain->revmap_data.linear.revmap[hwirq] = virq;
+		break;
+	case IRQ_DOMAIN_MAP_TREE:
+		mutex_lock(&revmap_trees_mutex);
+		irq_radix_revmap_insert(domain, virq, hwirq);
+		mutex_unlock(&revmap_trees_mutex);
+		break;
+	}
+
 	irq_clear_status_flags(virq, IRQ_NOREQUEST);
 
 	return 0;