[tip:irq/core] PCI/MSI: Allow msi_domain lookup using the host bridge node

[tip-bot for Marc Zyngier]

Commit-ID:  471c931cb248ab7af0cd62503d811239b47f217b
Gitweb:     http://git.kernel.org/tip/471c931cb248ab7af0cd62503d811239b47f217b
Author:     Marc Zyngier <marc.zyngier@xxxxxxx>
AuthorDate: Tue, 28 Jul 2015 14:46:13 +0100
Committer:  Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Thu, 30 Jul 2015 00:14:37 +0200

PCI/MSI: Allow msi_domain lookup using the host bridge node

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@xxxxxxxxxx>
Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx>
Cc: <linux-arm-kernel@xxxxxxxxxxxxxxxxxxx>
Cc: Yijing Wang <wangyijing@xxxxxxxxxx>
Cc: Ma Jun <majun258@xxxxxxxxxx>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
Cc: Duc Dang <dhdang@xxxxxxx>
Cc: Hanjun Guo <hanjun.guo@xxxxxxxxxx>
Cc: Jiang Liu <jiang.liu@xxxxxxxxxxxxxxx>
Cc: Jason Cooper <jason@xxxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/1438091186-10244-7-git-send-email-marc.zyngier@xxxxxxx
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
---
 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)
--
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