[PATCH] powerpc: xor_vmx: Add '-mhard-float' to CFLAGS

[Nathan Chancellor]

Ping? We have been applying this in our CI since it was sent, it would
be nice to have this upstream soon so it can start filtering through the
stable trees.

On Sat, Jan 27, 2024 at 11:07:43AM -0700, Nathan Chancellor wrote:
> arch/powerpc/lib/xor_vmx.o is built with '-msoft-float' (from the main
> powerpc Makefile) and '-maltivec' (from its CFLAGS), which causes an
> error when building with clang after a recent change in main:
> 
>   error: option '-msoft-float' cannot be specified with '-maltivec'
>   make[6]: *** [scripts/Makefile.build:243: arch/powerpc/lib/xor_vmx.o] Error 1
> 
> Explicitly add '-mhard-float' before '-maltivec' in xor_vmx.o's CFLAGS
> to override the previous inclusion of '-msoft-float' (as the last option
> wins), which matches how other areas of the kernel use '-maltivec', such
> as AMDGPU.
> 
> Cc: stable at vger.kernel.org
> Closes: https://github.com/ClangBuiltLinux/linux/issues/1986
> Link: https://github.com/llvm/llvm-project/commit/4792f912b232141ecba4cbae538873be3c28556c
> Signed-off-by: Nathan Chancellor <nathan at kernel.org>
> ---
>  arch/powerpc/lib/Makefile | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/powerpc/lib/Makefile b/arch/powerpc/lib/Makefile
> index 6eac63e79a89..0ab65eeb93ee 100644
> --- a/arch/powerpc/lib/Makefile
> +++ b/arch/powerpc/lib/Makefile
> @@ -76,7 +76,7 @@ obj-$(CONFIG_PPC_LIB_RHEAP) += rheap.o
>  obj-$(CONFIG_FTR_FIXUP_SELFTEST) += feature-fixups-test.o
>  
>  obj-$(CONFIG_ALTIVEC)	+= xor_vmx.o xor_vmx_glue.o
> -CFLAGS_xor_vmx.o += -maltivec $(call cc-option,-mabi=altivec)
> +CFLAGS_xor_vmx.o += -mhard-float -maltivec $(call cc-option,-mabi=altivec)
>  # Enable <altivec.h>
>  CFLAGS_xor_vmx.o += -isystem $(shell $(CC) -print-file-name=include)
>  
> 
> ---
> base-commit: 6613476e225e090cc9aad49be7fa504e290dd33d
> change-id: 20240127-ppc-xor_vmx-drop-msoft-float-ad68b437f86c
> 
> Best regards,
> -- 
> Nathan Chancellor <nathan at kernel.org>
>