[PATCH 4.18 107/145] iommu/ipmmu-vmsa: Dont register as BUS IOMMU if machine doesnt have IPMMU-VMSA

[Greg Kroah-Hartman]

4.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Dmitry Osipenko <digetx@xxxxxxxxx>

commit 5c5c87411488af3cd082221e567498d813d0fe83 upstream.

This fixes kernel crashing on NVIDIA Tegra if kernel is compiled in
a multiplatform configuration and IPMMU-VMSA driver is enabled.

Cc: <stable@xxxxxxxxxxxxxxx> # v3.20+
Signed-off-by: Dmitry Osipenko <digetx@xxxxxxxxx>
Signed-off-by: Joerg Roedel <jroedel@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/iommu/ipmmu-vmsa.c |    7 +++++++
 1 file changed, 7 insertions(+)

--- a/drivers/iommu/ipmmu-vmsa.c
+++ b/drivers/iommu/ipmmu-vmsa.c
@@ -1081,12 +1081,19 @@ static struct platform_driver ipmmu_driv
 
 static int __init ipmmu_init(void)
 {
+	struct device_node *np;
 	static bool setup_done;
 	int ret;
 
 	if (setup_done)
 		return 0;
 
+	np = of_find_matching_node(NULL, ipmmu_of_ids);
+	if (!np)
+		return 0;
+
+	of_node_put(np);
+
 	ret = platform_driver_register(&ipmmu_driver);
 	if (ret < 0)
 		return ret;