File-copy from v4.4.100

This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

Please refer to that tree for all history prior to this point.

Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
diff --git a/include/linux/of_iommu.h b/include/linux/of_iommu.h
new file mode 100644
index 0000000..ffbe470
--- /dev/null
+++ b/include/linux/of_iommu.h
@@ -0,0 +1,46 @@
+#ifndef __OF_IOMMU_H
+#define __OF_IOMMU_H
+
+#include <linux/device.h>
+#include <linux/iommu.h>
+#include <linux/of.h>
+
+#ifdef CONFIG_OF_IOMMU
+
+extern int of_get_dma_window(struct device_node *dn, const char *prefix,
+			     int index, unsigned long *busno, dma_addr_t *addr,
+			     size_t *size);
+
+extern void of_iommu_init(void);
+extern struct iommu_ops *of_iommu_configure(struct device *dev,
+					struct device_node *master_np);
+
+#else
+
+static inline int of_get_dma_window(struct device_node *dn, const char *prefix,
+			    int index, unsigned long *busno, dma_addr_t *addr,
+			    size_t *size)
+{
+	return -EINVAL;
+}
+
+static inline void of_iommu_init(void) { }
+static inline struct iommu_ops *of_iommu_configure(struct device *dev,
+					 struct device_node *master_np)
+{
+	return NULL;
+}
+
+#endif	/* CONFIG_OF_IOMMU */
+
+void of_iommu_set_ops(struct device_node *np, struct iommu_ops *ops);
+struct iommu_ops *of_iommu_get_ops(struct device_node *np);
+
+extern struct of_device_id __iommu_of_table;
+
+typedef int (*of_iommu_init_fn)(struct device_node *);
+
+#define IOMMU_OF_DECLARE(name, compat, fn) \
+	_OF_DECLARE(iommu, name, compat, fn, of_iommu_init_fn)
+
+#endif /* __OF_IOMMU_H */