[3/5] iommu/exynos: Ensure that SYSMMU is added only once to its master device

Commit Message

Marek Szyprowski Nov. 24, 2016, 11:20 a.m. UTC

This patch prepares Exynos IOMMU driver for deferred probing
support. Once it gets added, of_xlate() callback might be called
more than once for the same SYSMMU controller and master device
(for example it happens when masters device driver fails with
EPROBE_DEFER). This patch adds a check, which ensures that SYSMMU
controller is added to its master device (owner) only once.

Signed-off-by: Marek Szyprowski <[e-mail]>
---
 drivers/iommu/exynos-iommu.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

Patch

diff --git a/drivers/iommu/exynos-iommu.c b/drivers/iommu/exynos-iommu.c
index e7851cffbbee..426b1534d4d3 100644
--- a/drivers/iommu/exynos-iommu.c
+++ b/drivers/iommu/exynos-iommu.c
@@ -1247,7 +1247,7 @@  static int exynos_iommu_of_xlate(struct device *dev,
 {
 	struct exynos_iommu_owner *owner = dev->archdata.iommu;
 	struct platform_device *sysmmu = of_find_device_by_node(spec->np);
-	struct sysmmu_drvdata *data;
+	struct sysmmu_drvdata *data, *entry;
 
 	if (!sysmmu)
 		return -ENODEV;
@@ -1266,6 +1266,10 @@  static int exynos_iommu_of_xlate(struct device *dev,
 		dev->archdata.iommu = owner;
 	}
 
+	list_for_each_entry(entry, &owner->controllers, owner_node)
+		if (entry == data)
+			return 0;
+
 	list_add_tail(&data->owner_node, &owner->controllers);
 	data->master = dev;