# SPDX-License-Identifier: GPL-2.0
 
-ifeq ($(srctree),)
-srctree := $(patsubst %/,%,$(dir $(CURDIR)))
-srctree := $(patsubst %/,%,$(dir $(srctree)))
-srctree := $(patsubst %/,%,$(dir $(srctree)))
-srctree := $(patsubst %/,%,$(dir $(srctree)))
+ifeq ($(top_srcdir),)
+top_srcdir := $(patsubst %/,%,$(dir $(CURDIR)))
+top_srcdir := $(patsubst %/,%,$(dir $(top_srcdir)))
+top_srcdir := $(patsubst %/,%,$(dir $(top_srcdir)))
+top_srcdir := $(patsubst %/,%,$(dir $(top_srcdir)))
 endif
 
-include $(srctree)/tools/scripts/Makefile.include
+include $(top_srcdir)/tools/scripts/Makefile.include
 
 AWK    ?= awk
 MKDIR  ?= mkdir
 Q = @
 endif
 
-arm64_tools_dir = $(srctree)/arch/arm64/tools
+arm64_tools_dir = $(top_srcdir)/arch/arm64/tools
 arm64_sysreg_tbl = $(arm64_tools_dir)/sysreg
 arm64_gen_sysreg = $(arm64_tools_dir)/gen-sysreg.awk
-arm64_generated_dir = $(srctree)/tools/arch/arm64/include/generated
+arm64_generated_dir = $(top_srcdir)/tools/arch/arm64/include/generated
 arm64_sysreg_defs = $(arm64_generated_dir)/asm/sysreg-defs.h
 
 all: $(arm64_sysreg_defs)