From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1031124AbeCAOCt (ORCPT ); Thu, 1 Mar 2018 09:02:49 -0500 Received: from foss.arm.com ([217.140.101.70]:38914 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1030922AbeCAOCs (ORCPT ); Thu, 1 Mar 2018 09:02:48 -0500 Date: Thu, 1 Mar 2018 14:02:43 +0000 From: Mark Rutland To: Benjamin Gaignard Cc: robh+dt@kernel.org, mcoquelin.stm32@gmail.com, alexandre.torgue@st.com, robin.murphy@arm.com, arnd@arndb.de, loic.pallardy@st.com, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Benjamin Gaignard Subject: Re: [PATCH v2 0/2] STM32 Extended TrustZone Protection driver Message-ID: <20180301140243.3uamdvdcvmsxv6im@lakrids.cambridge.arm.com> References: <20180301135806.19982-1-benjamin.gaignard@st.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180301135806.19982-1-benjamin.gaignard@st.com> User-Agent: NeoMutt/20170113 (1.7.2) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Mar 01, 2018 at 02:58:04PM +0100, Benjamin Gaignard wrote: > On early boot stages STM32MP1 platform is able to dedicate some hardware blocks > to a secure OS running in TrustZone. > We need to avoid using those hardware blocks on non-secure context (i.e. kernel) > because read/write accesses could generate illegale access exceptions. > > Extended TrustZone Protection driver make sure that device is disabled if > non-secure world can't acces to it. > > version 2: > - do not use notifier anymore > - change status property value in device-tree if needed > - use a list of phandle instead of hard coded array As mentioned on v1, I don't think this should be done in Linux at all. If you wish to handle this dynamically, please fixup the DT *before* entering Linux. If you want a sane default in the dts file, put status = "disabled" on all nodes which the secure world might take ownership of. Thanks, Mark. > NOTE: Those patches should be applied only on > git://git.kernel.org/pub/scm/linux/kernel/git/atorgue/stm32.git stm32-next > until this patch: https://lkml.org/lkml/2018/2/26/386 > find it way to mainline because KBuild will complain about them. > > Benjamin Gaignard (2): > dt-bindings: stm32: Add bindings for Extended TrustZone Protection > ARM: mach-stm32: Add Extended TrustZone Protection driver > > .../bindings/arm/stm32/st,stm32mp1-etzpc.txt | 25 +++++ > arch/arm/mach-stm32/Kconfig | 7 ++ > arch/arm/mach-stm32/Makefile | 1 + > arch/arm/mach-stm32/stm32-etzpc.c | 116 +++++++++++++++++++++ > 4 files changed, 149 insertions(+) > create mode 100644 Documentation/devicetree/bindings/arm/stm32/st,stm32mp1-etzpc.txt > create mode 100644 arch/arm/mach-stm32/stm32-etzpc.c > > -- > 2.15.0 >