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:

quoted

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 Benn?e <redacted>
---
 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