[PATCH v2 09/10] kbuild: Add config fragment merge functionality

[Alexander Stein]

From: Nicolas Saenz Julienne <nsaenzjulienne at suse.de>

So far this function was only used locally in powerpc, some other
architectures might benefit from it. Move it into
scripts/Makefile.defconf.

Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne at suse.de>
Signed-off-by: Alexander Stein <alexander.stein at ew.tq-group.com>
---
Directly applied from https://lore.kernel.org/linux-arm-kernel/20200203184820.4433-2-nsaenzjulienne@suse.de/T/#m96968dd45c0aaa88e0a7387024b5ac13b002363d

 arch/powerpc/Makefile    | 12 +-----------
 scripts/Makefile.defconf | 15 +++++++++++++++
 2 files changed, 16 insertions(+), 11 deletions(-)
 create mode 100644 scripts/Makefile.defconf

diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile
index dc4cbf0a5ca95..533457466ce25 100644
--- a/arch/powerpc/Makefile
+++ b/arch/powerpc/Makefile
@@ -253,17 +253,7 @@ PHONY += bootwrapper_install
 bootwrapper_install:
 	$(Q)$(MAKE) $(build)=$(boot) $(patsubst %,$(boot)/%,$@)
 
-# Used to create 'merged defconfigs'
-# To use it $(call) it with the first argument as the base defconfig
-# and the second argument as a space separated list of .config files to merge,
-# without the .config suffix.
-define merge_into_defconfig
-	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/kconfig/merge_config.sh \
-		-m -O $(objtree) $(srctree)/arch/$(ARCH)/configs/$(1) \
-		$(foreach config,$(2),$(srctree)/arch/$(ARCH)/configs/$(config).config)
-	+$(Q)$(MAKE) -f $(srctree)/Makefile olddefconfig
-endef
-
+include $(srctree)/scripts/Makefile.defconf
 PHONY += pseries_le_defconfig
 pseries_le_defconfig:
 	$(call merge_into_defconfig,pseries_defconfig,le)
diff --git a/scripts/Makefile.defconf b/scripts/Makefile.defconf
new file mode 100644
index 0000000000000..ab332f7534f51
--- /dev/null
+++ b/scripts/Makefile.defconf
@@ -0,0 +1,15 @@
+# SPDX-License-Identifier: GPL-2.0
+# Configuration heplers
+
+# Creates 'merged defconfigs'
+# ---------------------------------------------------------------------------
+# Usage:
+#   $(call merge_into_defconfig,base_config,config_fragment1 config_fragment2 ...)
+#
+# Input config fragments without '.config' suffix
+define merge_into_defconfig
+	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/kconfig/merge_config.sh \
+		-m -O $(objtree) $(srctree)/arch/$(ARCH)/configs/$(1) \
+		$(foreach config,$(2),$(srctree)/arch/$(ARCH)/configs/$(config).config)
+	+$(Q)$(MAKE) -f $(srctree)/Makefile olddefconfig
+endef
-- 
2.34.1