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>
diff --git a/arch/powerpc/sysdev/xics/xics-common.c b/arch/powerpc/sysdev/xics/xics-common.c
index cd1d18d..9049d9f 100644
--- a/arch/powerpc/sysdev/xics/xics-common.c
+++ b/arch/powerpc/sysdev/xics/xics-common.c
@@ -329,9 +329,6 @@
 
 	pr_devel("xics: map virq %d, hwirq 0x%lx\n", virq, hw);
 
-	/* Insert the interrupt mapping into the radix tree for fast lookup */
-	irq_radix_revmap_insert(xics_host, virq, hw);
-
 	/* They aren't all level sensitive but we just don't really know */
 	irq_set_status_flags(virq, IRQ_LEVEL);
 
diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
index 17634f2..091732c 100644
--- a/kernel/irq/irqdomain.c
+++ b/kernel/irq/irqdomain.c
@@ -424,6 +424,18 @@
 		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;