v4.19.13 snapshot.
diff --git a/include/xen/swiotlb-xen.h b/include/xen/swiotlb-xen.h
new file mode 100644
index 0000000..5e4b83f
--- /dev/null
+++ b/include/xen/swiotlb-xen.h
@@ -0,0 +1,10 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __LINUX_SWIOTLB_XEN_H
+#define __LINUX_SWIOTLB_XEN_H
+
+#include <linux/swiotlb.h>
+
+extern int xen_swiotlb_init(int verbose, bool early);
+extern const struct dma_map_ops xen_swiotlb_dma_ops;
+
+#endif /* __LINUX_SWIOTLB_XEN_H */