v4.19.13 snapshot.
diff --git a/arch/xtensa/include/asm/flat.h b/arch/xtensa/include/asm/flat.h
new file mode 100644
index 0000000..b8532d7
--- /dev/null
+++ b/arch/xtensa/include/asm/flat.h
@@ -0,0 +1,24 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __ASM_XTENSA_FLAT_H
+#define __ASM_XTENSA_FLAT_H
+
+#include <asm/unaligned.h>
+
+#define flat_argvp_envp_on_stack() 0
+#define flat_old_ram_flag(flags) (flags)
+#define flat_reloc_valid(reloc, size) ((reloc) <= (size))
+static inline int flat_get_addr_from_rp(u32 __user *rp, u32 relval, u32 flags,
+ u32 *addr, u32 *persistent)
+{
+ *addr = get_unaligned((__force u32 *)rp);
+ return 0;
+}
+static inline int flat_put_addr_at_rp(u32 __user *rp, u32 addr, u32 rel)
+{
+ put_unaligned(addr, (__force u32 *)rp);
+ return 0;
+}
+#define flat_get_relocate_addr(rel) (rel)
+#define flat_set_persistent(relval, p) 0
+
+#endif /* __ASM_XTENSA_FLAT_H */