kbuild: warn redundant generic-y

The generic-y is redundant under the following condition:

 - arch has its own implementation

 - the same header is added to generated-y

 - the same header is added to mandatory-y

If a redundant generic-y is found, the warning like follows is displayed:

  scripts/Makefile.asm-generic:20: redundant generic-y found in arch/arm/include/asm/Kbuild: timex.h

I fixed up arch Kbuild files found by this.

Suggested-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/scripts/Makefile.asm-generic b/scripts/Makefile.asm-generic
index a62d2823f6cf..c7d2b7acad26 100644
--- a/scripts/Makefile.asm-generic
+++ b/scripts/Makefile.asm-generic
@@ -14,6 +14,12 @@ src := $(subst /generated,,$(obj))
 
 include scripts/Kbuild.include
 
+redundant := $(filter $(mandatory-y) $(generated-y), $(generic-y))
+redundant += $(foreach f, $(generic-y), $(if $(wildcard $(srctree)/$(src)/$(f)),$(f)))
+redundant := $(sort $(redundant))
+$(if $(redundant),\
+        $(warning redundant generic-y found in $(src)/Kbuild: $(redundant)))
+
 # If arch does not implement mandatory headers, fallback to asm-generic ones.
 mandatory-y := $(filter-out $(generated-y), $(mandatory-y))
 generic-y   += $(foreach f, $(mandatory-y), $(if $(wildcard $(srctree)/$(src)/$(f)),,$(f)))