From mboxrd@z Thu Jan 1 00:00:00 1970 From: Leif Lindholm Subject: Re: [PATCHv2 1/5] efi/runtime-wrappers: add {__,}efi_call_virt templates Date: Thu, 21 Apr 2016 12:42:56 +0100 Message-ID: <20160421114256.GP2904@bivouac.eciton.net> References: <1461238529-12810-1-git-send-email-mark.rutland@arm.com> <1461238529-12810-2-git-send-email-mark.rutland@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <1461238529-12810-2-git-send-email-mark.rutland-5wv7dgnIgG8@public.gmane.org> Sender: linux-efi-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Mark Rutland Cc: linux-efi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, ard.biesheuvel-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org, catalin.marinas-5wv7dgnIgG8@public.gmane.org, hpa-YMNOUZJC4hwAvxtiuMwx3w@public.gmane.org, linux-lFZ/pmaqli7XmaaqVzeoHQ@public.gmane.org, matt-mF/unelCI9GS6iBeEJttW/XRex20P6io@public.gmane.org, mingo-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, tglx-hfZtesqFncYOwBW4kG4KsQ@public.gmane.org, will.deacon-5wv7dgnIgG8@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-efi@vger.kernel.org On Thu, Apr 21, 2016 at 12:35:25PM +0100, Mark Rutland wrote: > Currently each architecture must implement two macros, efi_call_virt and > __efi_call_virt, which only differ by the presence or absence of a > return type. Otherwise, the logic surrounding the call is identical. > > As each architecture must define the entire body of each, we can't place > any generic manipulation (e.g. irq flag validation) in the middle. > > This patch adds template implementations of these macros. With these, > arch code can implement three template macros, avoiding reptition for > the void/non-void return cases: > > * arch_efi_call_virt_setup > > Sets up the environment for the call (e.g. switching page tables, > allowing kernel-mode use of floating point, if required). > > * arch_efi_call_virt > > Performs the call. The last expression in the macro must be the call > itself, allowing the logic to be shared by the void and non-void > cases. > > * arch_efi_call_virt_teardown > > Restores the usual kernel environment once the call has returned. > > While the savings from repition are minimal, we additionally gain the > ability to add common code around the call with the call enviroment set > up. This can be used to detect common firmware issues (e.g. bad irq mask > management). > > Signed-off-by: Mark Rutland > Cc: Matt Fleming > Cc: linux-efi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org > Cc: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org > --- > drivers/firmware/efi/runtime-wrappers.c | 21 +++++++++++++++++++++ > 1 file changed, 21 insertions(+) > > diff --git a/drivers/firmware/efi/runtime-wrappers.c b/drivers/firmware/efi/runtime-wrappers.c > index de69530..1b9fa54 100644 > --- a/drivers/firmware/efi/runtime-wrappers.c > +++ b/drivers/firmware/efi/runtime-wrappers.c > @@ -20,6 +20,27 @@ > #include > #include > > + > +#ifndef efi_call_virt So ... not a strong complaint, but I would prefer if these weren't ifdefd. I presume this is because ia64? Could that be given a dummy pass-through version instead? If not, could a comment be added that this is to retain compatibility with ia64 (so that if that architecture was to mysteriously disappear from the tree, someone might remember to deconditionalise it)? > +#define efi_call_virt(f, args...) \ > +({ \ > + efi_status_t __s; \ > + arch_efi_call_virt_setup(); \ > + __s = arch_efi_call_virt(f, args); \ > + arch_efi_call_virt_teardown(); \ > + __s; \ > +}) > +#endif > + > +#ifndef __efi_call_virt > +#define __efi_call_virt(f, args...) \ > +({ \ > + arch_efi_call_virt_setup(); \ > + arch_efi_call_virt(f, args); \ > + arch_efi_call_virt_teardown(); \ > +}) > +#endif > + > /* > * According to section 7.1 of the UEFI spec, Runtime Services are not fully > * reentrant, and there are particular combinations of calls that need to be > -- > 1.9.1 >