diff --git a/arch/loongarch/include/asm/io.h b/arch/loongarch/include/asm/io.h
index 5207da7c2a822f5fa50a5865de79b91aa186ba95..50cf485423a1488dfaa9427e0f3a063f9b08dd39 100644
--- a/arch/loongarch/include/asm/io.h
+++ b/arch/loongarch/include/asm/io.h
@@ -72,6 +72,8 @@ extern void __memcpy_fromio(void *to, const volatile void __iomem *from, size_t
 #define memcpy_fromio(a, c, l) __memcpy_fromio((a), (c), (l))
 #define memcpy_toio(c, a, l)   __memcpy_toio((c), (a), (l))
 
+#define __io_aw() mmiowb()
+
 #include <asm-generic/io.h>
 
 #endif /* _ASM_IO_H */