v4.19.13 snapshot.
diff --git a/tools/testing/radix-tree/linux/gfp.h b/tools/testing/radix-tree/linux/gfp.h
new file mode 100644
index 0000000..32159c0
--- /dev/null
+++ b/tools/testing/radix-tree/linux/gfp.h
@@ -0,0 +1,33 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _GFP_H
+#define _GFP_H
+
+#include <linux/types.h>
+
+#define __GFP_BITS_SHIFT 26
+#define __GFP_BITS_MASK ((gfp_t)((1 << __GFP_BITS_SHIFT) - 1))
+
+#define __GFP_HIGH 0x20u
+#define __GFP_IO 0x40u
+#define __GFP_FS 0x80u
+#define __GFP_NOWARN 0x200u
+#define __GFP_ZERO 0x8000u
+#define __GFP_ATOMIC 0x80000u
+#define __GFP_ACCOUNT 0x100000u
+#define __GFP_DIRECT_RECLAIM 0x400000u
+#define __GFP_KSWAPD_RECLAIM 0x2000000u
+
+#define __GFP_RECLAIM (__GFP_DIRECT_RECLAIM|__GFP_KSWAPD_RECLAIM)
+
+#define GFP_ZONEMASK 0x0fu
+#define GFP_ATOMIC (__GFP_HIGH|__GFP_ATOMIC|__GFP_KSWAPD_RECLAIM)
+#define GFP_KERNEL (__GFP_RECLAIM | __GFP_IO | __GFP_FS)
+#define GFP_NOWAIT (__GFP_KSWAPD_RECLAIM)
+
+
+static inline bool gfpflags_allow_blocking(const gfp_t gfp_flags)
+{
+ return !!(gfp_flags & __GFP_DIRECT_RECLAIM);
+}
+
+#endif