4.14-stable review patch. If anyone has any objections, please let me know.
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From: Robin Murphy robin.murphy@arm.com
[ Upstream commit dc98b8480d8a68c2ce9aa28b9f0d714fd258bc0b ]
Removing the early device registration hook overlooked the fact that it only ran conditionally on a compatible device being present in the DT. With exynos_iommu_init() now running as an unconditional initcall, problems arise on non-Exynos systems when other IOMMU drivers find themselves unable to install their ops on the platform bus, or at worst the Exynos ops get called with someone else's domain and all hell breaks loose.
The global ops/cache setup could probably all now be triggered from the first IOMMU probe, as with dma_dev assigment, but for the time being the simplest fix is to resurrect the logic from commit a7b67cd5d9af ("iommu/exynos: Play nice in multi-platform builds") to explicitly check the DT for the presence of an Exynos IOMMU before trying anything.
Fixes: 928055a01b3f ("iommu/exynos: Remove custom platform device registration code") Signed-off-by: Robin Murphy robin.murphy@arm.com Acked-by: Marek Szyprowski m.szyprowski@samsung.com Signed-off-by: Joerg Roedel jroedel@suse.de Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/iommu/exynos-iommu.c | 7 +++++++ 1 file changed, 7 insertions(+)
--- a/drivers/iommu/exynos-iommu.c +++ b/drivers/iommu/exynos-iommu.c @@ -1344,8 +1344,15 @@ static const struct iommu_ops exynos_iom
static int __init exynos_iommu_init(void) { + struct device_node *np; int ret;
+ np = of_find_matching_node(NULL, sysmmu_of_match); + if (!np) + return 0; + + of_node_put(np); + lv2table_kmem_cache = kmem_cache_create("exynos-iommu-lv2table", LV2TABLE_SIZE, LV2TABLE_SIZE, 0, NULL); if (!lv2table_kmem_cache) {