Re: [PATCH v3 03/28] arm64: efi: Add missing Kconfig dependency on KERNEL_MODE_NEON

Dave Martin
2017-10-11T14:35:33Z

On Wed, Oct 11, 2017 at 03:16:47PM +0100, Catalin Marinas wrote:
> On Tue, Oct 10, 2017 at 07:38:20PM +0100, Dave P Martin wrote:
> > The EFI runtime services ABI permits calls to EFI to clobber
> > certain FPSIMD/NEON registers, as per the AArch64 procedure call
> > standard.
> >
> > Saving/restoring the clobbered registers around such calls needs
> > KERNEL_MODE_NEON, but the dependency is missing from Kconfig.
> >
> > This patch adds the missing dependency.
> >
> > This will aid bisection of the patches implementing support for the
> > ARM Scalable Vector Extension (SVE).
> >
> > Signed-off-by: Dave Martin <Dave.Martin@arm.com>
> > Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
> > ---
> > arch/arm64/Kconfig | 1 +
> > 1 file changed, 1 insertion(+)
> >
> > diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
> > index 0df64a6..ca711ac 100644
> > --- a/arch/arm64/Kconfig
> > +++ b/arch/arm64/Kconfig
> > @@ -1063,6 +1063,7 @@ config EFI_STUB
> > config EFI
> > bool "UEFI runtime support"
> > depends on OF && !CPU_BIG_ENDIAN
> > + depends on KERNEL_MODE_NEON
> > select LIBFDT
> > select UCS2_STRING
> > select EFI_PARAMS_FROM_FDT
>
> We could've used select KERNEL_MODE_NEON since it's a feature needed by
> EFI but this works for me as well as KERNEL_MODE_NEON is def_bool y
> already. Either way:
>
> Acked-by: Catalin Marinas <catalin.marinas@arm.com>

Agreed. I assumed this is moot anyway, since KERNEL_MODE_NEON will
rarely/never be deselected in practice.

Cheers
---Dave