diff --git a/arch/xtensa/kernel/setup.c b/arch/xtensa/kernel/setup.c
index c0ec243..176cb46 100644
--- a/arch/xtensa/kernel/setup.c
+++ b/arch/xtensa/kernel/setup.c
@@ -310,7 +310,8 @@ extern char _SecondaryResetVector_text_start;
 extern char _SecondaryResetVector_text_end;
 #endif
 
-static inline int mem_reserve(unsigned long start, unsigned long end)
+static inline int __init_memblock mem_reserve(unsigned long start,
+					      unsigned long end)
 {
 	return memblock_reserve(start, end - start);
 }