This is a note to let you know that I've just added the patch titled
kbuild: Add support for 'as-instr' to be used in Kconfig files
to the 4.19-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
kbuild-add-support-for-as-instr-to-be-used-in-kconfi.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 581facfa38acbfd79612de1902e812059c6cf149
Author: Catalin Marinas <catalin.marinas@xxxxxxx>
Date: Wed Jan 15 11:30:07 2020 +0000
kbuild: Add support for 'as-instr' to be used in Kconfig files
commit 42d519e3d0c071161d0a1c36e95a3743b113c590 upstream.
Similar to 'cc-option' or 'ld-option', it is occasionally necessary to
check whether the assembler supports certain ISA extensions. In the
arm64 code we currently do this in Makefile with an additional define:
lseinstr := $(call as-instr,.arch_extension lse,-DCONFIG_AS_LSE=1)
Add the 'as-instr' option so that it can be used in Kconfig directly:
def_bool $(as-instr,.arch_extension lse)
Acked-by: Masahiro Yamada <masahiroy@xxxxxxxxxx>
Reviewed-by: Vladimir Murzin <vladimir.murzin@xxxxxxx>
Tested-by: Vladimir Murzin <vladimir.murzin@xxxxxxx>
Signed-off-by: Catalin Marinas <catalin.marinas@xxxxxxx>
Signed-off-by: Will Deacon <will@xxxxxxxxxx>
Signed-off-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/scripts/Kconfig.include b/scripts/Kconfig.include
index 79455ad6b386..b762e02c0c31 100644
--- a/scripts/Kconfig.include
+++ b/scripts/Kconfig.include
@@ -26,5 +26,16 @@ cc-option = $(success,$(CC) -Werror $(CLANG_FLAGS) $(1) -S -x c /dev/null -o /de
# Return y if the linker supports <flag>, n otherwise
ld-option = $(success,$(LD) -v $(1))
+# $(as-instr,<instr>)
+# Return y if the assembler supports <instr>, n otherwise
+as-instr = $(success,printf "%b\n" "$(1)" | $(CC) $(CLANG_FLAGS) -c -x assembler -o /dev/null -)
+
+# check if $(CC) and $(LD) exist
+$(error-if,$(failure,command -v $(CC)),compiler '$(CC)' not found)
+$(error-if,$(failure,command -v $(LD)),linker '$(LD)' not found)
+
+# Fail if the linker is gold as it's not capable of linking the kernel proper
+$(error-if,$(success, $(LD) -v | grep -q gold), gold linker '$(LD)' not supported)
+
# gcc version including patch level
gcc-version := $(shell,$(srctree)/scripts/gcc-version.sh -p $(CC) | sed 's/^0*//')
