v4.19.13 snapshot.
diff --git a/arch/powerpc/include/asm/linkage.h b/arch/powerpc/include/asm/linkage.h
new file mode 100644
index 0000000..1f00d28
--- /dev/null
+++ b/arch/powerpc/include/asm/linkage.h
@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_POWERPC_LINKAGE_H
+#define _ASM_POWERPC_LINKAGE_H
+
+#include <asm/types.h>
+
+#ifdef PPC64_ELF_ABI_v1
+#define cond_syscall(x) \
+ asm ("\t.weak " #x "\n\t.set " #x ", sys_ni_syscall\n" \
+ "\t.weak ." #x "\n\t.set ." #x ", .sys_ni_syscall\n")
+#define SYSCALL_ALIAS(alias, name) \
+ asm ("\t.globl " #alias "\n\t.set " #alias ", " #name "\n" \
+ "\t.globl ." #alias "\n\t.set ." #alias ", ." #name)
+#endif
+
+#endif /* _ASM_POWERPC_LINKAGE_H */