Subject: [PATCH v2 2/2] efi/arm64: preserve FP/SIMD registers on UEFI runtime services calls

From: [email-masked] (Catalin Marinas)
Date: Fri, 4 Jul 2014 16:45:23 +0100

On Thu, Jun 26, 2014 at 11:09:06AM +0100, Ard Biesheuvel wrote:
> According to the UEFI spec section 2.3.6.4, the use of FP/SIMD instructions is
> allowed, and should adhere to the AAPCS64 calling convention, which states that
> 'only the bottom 64 bits of each value stored in registers v8-v15 need to be
> preserved' (section 5.1.2).
> 
> This applies equally to UEFI Runtime Services called by the kernel, so make sure
> the FP/SIMD register file is preserved in this case.
> 
> Signed-off-by: Ard Biesheuvel <[email-masked]>

While the code looks fine, I think there is a mismatch between what the
subject says and what the patch does (enabling EFI_RUNTIME_WRAPPERS).

-- 
Catalin