iommu/ipmmu-vmsa: Don't register as BUS IOMMU if machine doesn't have IPMMU-VMSA

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

Cc: <stable@vger.kernel.org> # v3.20+
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

1 files changed, 7 insertions, 0 deletions

diff --git a/drivers/iommu/ipmmu-vmsa.c b/drivers/iommu/ipmmu-vmsa.c
index 41eee3401f05..51af2c528a31 100644
--- a/drivers/iommu/ipmmu-vmsa.c
+++ b/drivers/iommu/ipmmu-vmsa.c
@@ -1108,12 +1108,19 @@ static struct platform_driver ipmmu_driver = {
 
 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;