2 files changed, 29 insertions, 0 deletions

diff --git a/drivers/of/address.c b/drivers/of/address.c
index c54baee87d93..d244b2859aac 100644
--- a/drivers/of/address.c
+++ b/drivers/of/address.c
@@ -808,3 +808,26 @@ out:
         return ret;
 }
 EXPORT_SYMBOL_GPL(of_dma_get_range);
+
+/**
+ * of_dma_is_coherent - Check if device is coherent
+ * @np: device node
+ *
+ * It returns true if "dma-coherent" property was found
+ * for this device in DT.
+ */
+bool of_dma_is_coherent(struct device_node *np)
+{
+        struct device_node *node = of_node_get(np);
+
+        while (node) {
+                if (of_property_read_bool(node, "dma-coherent")) {
+                        of_node_put(node);
+                        return true;
+                }
+                node = of_get_next_parent(node);
+        }
+        of_node_put(node);
+        return false;
+}
+EXPORT_SYMBOL_GPL(of_dma_is_coherent);
\ No newline at end of file
diff --git a/include/linux/of_address.h b/include/linux/of_address.h
index 4d7b325af2ca..839a3521b28e 100644
--- a/include/linux/of_address.h
+++ b/include/linux/of_address.h
@@ -65,6 +65,7 @@ extern struct of_pci_range *of_pci_range_parser_one(
                                         struct of_pci_range *range);
 extern int of_dma_get_range(struct device_node *np, u64 *dma_addr,
                                 u64 *paddr, u64 *size);
+extern bool of_dma_is_coherent(struct device_node *np);
 #else /* CONFIG_OF_ADDRESS */
 static inline struct device_node *of_find_matching_node_by_address(
                                         struct device_node *from,
@@ -98,6 +99,11 @@ static inline int of_dma_get_range(struct device_node *np, u64 *dma_addr,
 {
         return -ENODEV;
 }
+
+static inline bool of_dma_is_coherent(struct device_node *np)
+{
+        return false;
+}
 #endif /* CONFIG_OF_ADDRESS */
 
 #ifdef CONFIG_OF