[PATCH RESEND 2/3] PCI: irqdomain: Look up IRQ domain by fwnode_handle

[jakeo@microsoft.com]

From: Jake Oshins <jakeo@microsoft.com>

This patch adds a second way of finding an IRQ domain associated with
a root PCI bus.  After looking to see if one can be found through
the OF tree, it attempts to look up the IRQ domain through an
fwnode_handle stored in the pci_sysdata struct.

Signed-off-by: Jake Oshins <jakeo@microsoft.com>
---
 drivers/pci/probe.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index b207e74..1e34d21 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -676,6 +676,20 @@ static struct irq_domain *pci_host_bridge_msi_domain(struct pci_bus *bus)
 	if (!d)
 		d = pci_host_bridge_acpi_msi_domain(bus);
 
+#ifdef CONFIG_PCI_MSI_IRQ_DOMAIN
+	/*
+	 * If no IRQ domain was found via the OF tree, try looking it up
+	 * directly through the fwnode_handle.
+	 */
+	if (!d) {
+		struct fwnode_handle *fwnode = pci_root_bus_fwnode(bus);
+
+		if (fwnode)
+			d = irq_find_matching_fwnode(fwnode,
+						     DOMAIN_BUS_PCI_MSI);
+	}
+#endif
+
 	return d;
 }
 
-- 
1.9.1