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

BugLink: https://bugs.launchpad.net/bugs/1783746
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@vger.kernel.org> # v3.20+
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 3245925a8e9c4fb5f2ccb2b7c21d2cb35ce8725a)
Signed-off-by: Paolo Pisati <paolo.pisati@canonical.com>
Acked-by: Stefan Bader <stefan.bader@canonical.com>
Acked-by: Colin King <colin.king@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

diff --git a/drivers/iommu/ipmmu-vmsa.c b/drivers/iommu/ipmmu-vmsa.c
index 8dce3a9de9d86e37b66dce131952aa19e0aadb2a..2435103350cbf20ac5369f666935238421960e2e 100644 (file)
--- a/drivers/iommu/ipmmu-vmsa.c
+++ b/drivers/iommu/ipmmu-vmsa.c
@@ -1081,12 +1081,19 @@ 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;