mac802154: add ieee802154_le64_to_be64

This patch adds a new function to convert a le64 to a be64. This is
useful to translate an extended address to a netdev dev_addr.
Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

include/net/mac802154.h

@@ -17,6 +17,7 @@
 #define NET_MAC802154_H
 
 #include <net/af_ieee802154.h>
+#include <linux/ieee802154.h>
 #include <linux/skbuff.h>
 
 /* General MAC frame format:
@@ -231,6 +232,18 @@ static inline __le64 ieee802154_netdev_to_extended_addr(const void *dev_addr)
 	return (__force __le64)swab64p(dev_addr);
 }
 
+/**
+ * ieee802154_le64_to_be64 - copies and convert le64 to be64
+ * @be64_dst: be64 destination pointer
+ * @le64_src: le64 source pointer
+ */
+static inline void ieee802154_le64_to_be64(void *be64_dst, const void *le64_src)
+{
+	__be64 tmp = (__force __be64)swab64p(le64_src);
+
+	memcpy(be64_dst, &tmp, IEEE802154_EXTENDED_ADDR_LEN);
+}
+
 /* Basic interface to register ieee802154 hwice */
 struct ieee802154_hw *
 ieee802154_alloc_hw(size_t priv_data_len, const struct ieee802154_ops *ops);