Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754747Ab3ILKAX (ORCPT ); Thu, 12 Sep 2013 06:00:23 -0400 Received: from mail-ie0-f174.google.com ([209.85.223.174]:43246 "EHLO mail-ie0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751168Ab3ILKAV (ORCPT ); Thu, 12 Sep 2013 06:00:21 -0400 MIME-Version: 1.0 In-Reply-To: <522DF058.8020509@wwwdotorg.org> References: <1378351680-14696-1-git-send-email-acourbot@nvidia.com> <1378351680-14696-2-git-send-email-acourbot@nvidia.com> <522A2D1B.3010508@wwwdotorg.org> <522DF058.8020509@wwwdotorg.org> From: Alexandre Courbot Date: Thu, 12 Sep 2013 19:00:00 +0900 Message-ID: Subject: Re: [PATCH v5 1/5] ARM: add basic Trusted Foundations support To: Stephen Warren Cc: Alexandre Courbot , Russell King , Tomasz Figa , Dave Martin , Olof Johansson , Arnd Bergmann , Kevin Hilman , "devicetree@vger.kernel.org" , Linux Kernel Mailing List , "linux-tegra@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2598 Lines: 55 On Tue, Sep 10, 2013 at 12:59 AM, Stephen Warren wrote: > On 09/09/2013 12:38 AM, Alexandre Courbot wrote: >> On Sat, Sep 7, 2013 at 4:29 AM, Stephen Warren wrote: >>> On 09/04/2013 09:27 PM, Alexandre Courbot wrote: >>>> Trusted Foundations is a TrustZone-based secure monitor for ARM that >>>> can be invoked using a consistent SMC-based API on all supported >>>> platforms. This patch adds initial basic support for Trusted >>>> Foundations using the ARM firmware API. Current features are limited >>>> to the ability to boot secondary processors. > >>>> diff --git a/arch/arm/include/asm/trusted_foundations.h b/arch/arm/include/asm/trusted_foundations.h >>> >>> Do we need to add the following here: >>> >>> #if !IS_ENABLED(CONFIG_OF) >>> static inline void register_trusted_foundations(...) {} >>> #endif > > Uggh. I meant to write **of_**register_trusted_foundations() there. > >>> So that there is a dummy no-op function for the non-DT-support case? I >>> guess Tegra always has CONFIG_OF enabled so that call from >>> mach-tegra/common.c in patch 2 will never be an issue, but perhaps it >>> might if anyone else uses this? >> >> My expectation is that register_trusted_foundations() is called by the >> platform code once it has established (through whatever mean it likes) >> that Trusted Foundations is required. For platforms supporting DT, >> of_register_trusted_foundations() takes care of that. Platforms that >> don't support DT need another way to decide whether they *need* TF or >> not. Once a platform decided that it needs TF, its absence is not an >> option, and therefore I'd think that register_trusted_foundations() >> should hard-fail if support is not compiled in. Or maybe I missed your >> point? > > So yes, you missed my point, but it was my fault:-) > > Most of_* can be called irrespective of CONFIG_OF, and since > of_register_trusted_foundations() is meant to handle internally the "do > I need to do anything" case, I think it makes sense to be allowed to > call it unconditionally without determining anything about either > CONFIG_OF or TF DT node presence? Ah, ok, I follow you now. I wasn't sure what the convention was here, but yeah, I see nothing against making a no-op of_register_trusted_foundations() available when CONFIG_OF is not enabled. Thanks, Alex. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/