irqchip/gicv3-its: Register irq domain with NEXUS token

Now that we can distinguish between multiple domains carrying the
same device_node, tag the raw ITS domain with DOMAIN_BUS_NEXUS.
This will allow MSI providers built on top of the raw ITS domain
to identify it.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: <linux-arm-kernel@lists.infradead.org>
Cc: Yijing Wang <wangyijing@huawei.com>
Cc: Ma Jun <majun258@huawei.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Duc Dang <dhdang@apm.com>
Cc: Hanjun Guo <hanjun.guo@linaro.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Jason Cooper <jason@lakedaemon.net>
Link: http://lkml.kernel.org/r/1438091186-10244-13-git-send-email-marc.zyngier@arm.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

drivers/irqchip/irq-gic-v3-its.c

@@ -1444,13 +1444,14 @@ static int its_probe(struct device_node *node, struct irq_domain *parent)
 	writel_relaxed(GITS_CTLR_ENABLE, its->base + GITS_CTLR);
 
 	if (of_property_read_bool(its->msi_chip.of_node, "msi-controller")) {
-		its->domain = irq_domain_add_tree(NULL, &its_domain_ops, its);
+		its->domain = irq_domain_add_tree(node, &its_domain_ops, its);
 		if (!its->domain) {
 			err = -ENOMEM;
 			goto out_free_tables;
 		}
 
 		its->domain->parent = parent;
+		its->domain->bus_token = DOMAIN_BUS_NEXUS;
 
 		its->msi_chip.domain = its_pci_msi_alloc_domain(node,
 								its->domain);