[PATCH v6 06/19] PCI/MSI: of: Allow msi_domain lookup using the host bridge node

[marc.zyngier@arm.com (Marc Zyngier)]

A number of platforms do not need to use the msi-parent property,
as the host bridge itself provides the MSI controller.

Allow this configuration by performing an irq domain lookup based
on the host bridge node if it doesn't have a valid msi-parent property.

Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 drivers/pci/of.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/of.c b/drivers/pci/of.c
index 85844d8..2e99a50 100644
--- a/drivers/pci/of.c
+++ b/drivers/pci/of.c
@@ -72,8 +72,13 @@ struct irq_domain *pci_host_bridge_of_msi_domain(struct pci_bus *bus)
 
 	/* Start looking for a phandle to an MSI controller. */
 	np = of_parse_phandle(bus->dev.of_node, "msi-parent", 0);
+
+	/*
+	 * If we don't have an msi-parent property, look for a domain
+	 * directly attached to the host bridge.
+	 */
 	if (!np)
-		return NULL;
+		np = bus->dev.of_node;
 
 	d = irq_find_matching_host(np, DOMAIN_BUS_PCI_MSI);
 	if (d)
-- 
2.1.4