kbuild: split device tree build rules into scripts/Makefile.dtbs

scripts/Makefile.lib is included not only from scripts/Makefile.build
but also from scripts/Makefile.{modfinal,package,vmlinux,vmlinux_o},
where DT build rules are not required.

Split the DT build rules out to scripts/Makefile.dtbs, and include it
only when necessary.

While I was here, I added $(DT_TMP_SCHEMA) as a prerequisite of
$(multi-dtb-y).

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>

1 files changed, 8 insertions, 17 deletions

diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index 4b6942653093..8403eba15457 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -57,7 +57,6 @@ endif
 # subdir-builtin and subdir-modorder may contain duplications. Use $(sort ...)
 subdir-builtin := $(sort $(filter %/built-in.a, $(real-obj-y)))
 subdir-modorder := $(sort $(filter %/modules.order, $(obj-m)))
-subdir-dtbslist := $(sort $(filter %/dtbs-list, $(dtb-y)))
 
 targets-for-builtin := $(extra-y)
 
@@ -349,7 +348,7 @@ $(obj)/%.o: $(obj)/%.S FORCE
 
 targets += $(filter-out $(subdir-builtin), $(real-obj-y))
 targets += $(filter-out $(subdir-modorder), $(real-obj-m))
-targets += $(real-dtb-y) $(lib-y) $(always-y)
+targets += $(lib-y) $(always-y)
 
 # Linker scripts preprocessor (.lds.S -> .lds)
 # ---------------------------------------------------------------------------
@@ -375,7 +374,6 @@ $(obj)/%.asn1.c $(obj)/%.asn1.h: $(src)/%.asn1 $(objtree)/scripts/asn1_compiler
 # To build objects in subdirs, we need to descend into the directories
 $(subdir-builtin): $(obj)/%/built-in.a: $(obj)/% ;
 $(subdir-modorder): $(obj)/%/modules.order: $(obj)/% ;
-$(subdir-dtbslist): $(obj)/%/dtbs-list: $(obj)/% ;
 
 #
 # Rule to compile a set of .o files into one .a file (without symbol table)
@@ -391,12 +389,8 @@ quiet_cmd_ar_builtin = AR      $@
 $(obj)/built-in.a: $(real-obj-y) FORCE
 	$(call if_changed,ar_builtin)
 
-#
-# Rule to create modules.order and dtbs-list
-#
-# This is a list of build artifacts (module or dtb) from the current Makefile
-# and its sub-directories. The timestamp should be updated when any of the
-# member files.
+# This is a list of build artifacts from the current Makefile and its
+# sub-directories. The timestamp should be updated when any of the member files.
 
 cmd_gen_order = { $(foreach m, $(real-prereqs), \
 	$(if $(filter %/$(notdir $@), $m), cat $m, echo $m);) :; } \
@@ -405,9 +399,6 @@ cmd_gen_order = { $(foreach m, $(real-prereqs), \
 $(obj)/modules.order: $(obj-m) FORCE
 	$(call if_changed,gen_order)
 
-$(obj)/dtbs-list: $(dtb-y) FORCE
-	$(call if_changed,gen_order)
-
 #
 # Rule to compile a set of .o files into one .a file (with symbol table)
 #
@@ -436,11 +427,7 @@ intermediate_targets = $(foreach sfx, $(2), \
 				$(patsubst %$(strip $(1)),%$(sfx), \
 					$(filter %$(strip $(1)), $(targets))))
 # %.asn1.o <- %.asn1.[ch] <- %.asn1
-# %.dtb.o <- %.dtb.S <- %.dtb <- %.dts
-# %.dtbo.o <- %.dtbo.S <- %.dtbo <- %.dtso
-targets += $(call intermediate_targets, .asn1.o, .asn1.c .asn1.h) \
-	   $(call intermediate_targets, .dtb.o, .dtb.S .dtb) \
-	   $(call intermediate_targets, .dtbo.o, .dtbo.S .dtbo)
+targets += $(call intermediate_targets, .asn1.o, .asn1.c .asn1.h)
 
 # Include additional build rules when necessary
 # ---------------------------------------------------------------------------
@@ -457,6 +444,10 @@ ifneq ($(userprogs),)
 include $(srctree)/scripts/Makefile.userprogs
 endif
 
+ifneq ($(need-dtbslist)$(dtb-y)$(dtb-)$(filter %.dtb %.dtb.o %.dtbo.o,$(targets)),)
+include $(srctree)/scripts/Makefile.dtbs
+endif
+
 # Build
 # ---------------------------------------------------------------------------