v4.19.13 snapshot.
diff --git a/include/linux/zbud.h b/include/linux/zbud.h
new file mode 100644
index 0000000..b1eaf6e
--- /dev/null
+++ b/include/linux/zbud.h
@@ -0,0 +1,23 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ZBUD_H_
+#define _ZBUD_H_
+
+#include <linux/types.h>
+
+struct zbud_pool;
+
+struct zbud_ops {
+ int (*evict)(struct zbud_pool *pool, unsigned long handle);
+};
+
+struct zbud_pool *zbud_create_pool(gfp_t gfp, const struct zbud_ops *ops);
+void zbud_destroy_pool(struct zbud_pool *pool);
+int zbud_alloc(struct zbud_pool *pool, size_t size, gfp_t gfp,
+ unsigned long *handle);
+void zbud_free(struct zbud_pool *pool, unsigned long handle);
+int zbud_reclaim_page(struct zbud_pool *pool, unsigned int retries);
+void *zbud_map(struct zbud_pool *pool, unsigned long handle);
+void zbud_unmap(struct zbud_pool *pool, unsigned long handle);
+u64 zbud_get_pool_size(struct zbud_pool *pool);
+
+#endif /* _ZBUD_H_ */