iommu/exynos: Suppress unbinding to prevent system failure

Removal of IOMMU driver cannot be done reliably, so Exynos IOMMU driver
doesn't support this operation. It is essential for system operation, so
it makes sense to prevent unbinding by disabling bind/unbind sysfs
feature for SYSMMU controller driver to avoid kernel ops or trashing
memory caused by such operation.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
CC: stable@vger.kernel.org  # v4.2+
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

diff --git a/drivers/iommu/exynos-iommu.c b/drivers/iommu/exynos-iommu.c
index 5ecc86cb74c81f3194732ea6469b4e813a206bf5..e27e3b7df4e73e8ab49c4d589408600488b14c83 100644 (file)
--- a/drivers/iommu/exynos-iommu.c
+++ b/drivers/iommu/exynos-iommu.c
@@ -709,6 +709,7 @@ static struct platform_driver exynos_sysmmu_driver __refdata = {
                .name           = "exynos-sysmmu",
                .of_match_table = sysmmu_of_match,
                .pm             = &sysmmu_pm_ops,
+               .suppress_bind_attrs = true,
        }
 };