From mboxrd@z Thu Jan 1 00:00:00 1970 From: Catalin Marinas Subject: Re: [PATCH v2 2/2] efi/arm64: preserve FP/SIMD registers on UEFI runtime services calls Date: Fri, 4 Jul 2014 16:45:23 +0100 Message-ID: <20140704154522.GJ16404@arm.com> References: <1403777346-28629-1-git-send-email-ard.biesheuvel@linaro.org> <1403777346-28629-3-git-send-email-ard.biesheuvel@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <1403777346-28629-3-git-send-email-ard.biesheuvel-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org> Sender: linux-efi-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Ard Biesheuvel Cc: "matt.fleming-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org" , "x86-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org" , "linux-efi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org" , "hpa-YMNOUZJC4hwAvxtiuMwx3w@public.gmane.org" , "leif.lindholm-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org" , "roy.franz-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org" , "msalter-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org" , Olivier Martin List-Id: linux-efi@vger.kernel.org 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 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