diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
index ec2ee720e33e..f33e6aed3037 100644
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S
@@ -18,6 +18,7 @@
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
+#include <linux/arm-smccc.h>
#include <linux/init.h>
#include <linux/linkage.h>
@@ -137,6 +138,18 @@ alternative_else_nop_endif
add \dst, \dst, #(\sym - .entry.tramp.text)
.endm
+ // This macro corrupts x0-x3. It is the caller's duty
+ // to save/restore them if required.