Re: [PATCH v2 0/2] arm64: Simplify gas LSE support detection

Vladimir Murzin
2020-01-15T12:49:34Z

On 1/15/20 11:30 AM, Catalin Marinas wrote:
> Version two of the patch series moving the LSE assembler support
> detection from Makefile to Kconfig.
>
> Changes since v1 [1]:
>
> - Re-introduce the Makefile warning if the .config contains
> CONFIG_ARM64_USE_LSE_ATOMICS but the assembler does not support the
> feature, disabling CONFIG_ARM64_LSE_ATOMICS.
>
> [1] http://lkml.kernel.org/r/20200109174948.48211-1-catalin.marinas@arm.com
>
> Catalin Marinas (2):
> kbuild: Add support for 'as-instr' to be used in Kconfig files
> arm64: Move the LSE gas support detection to Kconfig
>
> arch/arm64/Kconfig | 5 +++++
> arch/arm64/Makefile | 11 ++++-------
> arch/arm64/include/asm/atomic_ll_sc.h | 2 +-
> arch/arm64/include/asm/lse.h | 6 +++---
> arch/arm64/kernel/cpufeature.c | 4 ++--
> scripts/Kconfig.include | 4 ++++
> 6 files changed, 19 insertions(+), 13 deletions(-)
>
>

with

aarch64-linux-gnu-gcc (crosstool-NG linaro-1.13.1-4.9-2014.09 - Linaro GCC 4.9-2014.09) 4.9.2 20140904 (prerelease)

I see (among other warnings)

arch/arm64/Makefile:35: LSE atomics not supported by binutils

while with

aarch64-none-linux-gnu-gcc (GNU Toolchain for the A-profile Architecture 9.2-2019.12 (arm-9.10)) 9.2.1 20191025

warning disappears.

FWIW:

Reviewed-by: Vladimir Murzin <vladimir.murzin@arm.com>
Tested-by: Vladimir Murzin <vladimir.murzin@arm.com>

Thanks
Vladimir