From mboxrd@z Thu Jan 1 00:00:00 1970 From: Maxime Ripard Subject: Re: [PATCH v4 10/10] ARM: sunxi: smp: Add initialization of CNTVOFF Date: Mon, 19 Mar 2018 11:59:11 +0100 Message-ID: <20180319105911.o63otbbhld54br4r@flea> References: <20180223133742.26044-1-mylene.josserand@bootlin.com> <20180223133742.26044-11-mylene.josserand@bootlin.com> <6329fbb6-13a1-41fe-f6cf-f2f0d4b2e5f9@arm.com> <20180318200715.363f3135@dell-desktop.home> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8BIT Return-path: Content-Disposition: inline In-Reply-To: <20180318200715.363f3135@dell-desktop.home> Sender: linux-kernel-owner@vger.kernel.org To: =?utf-8?Q?Myl=C3=A8ne?= Josserand Cc: Marc Zyngier , linux@armlinux.org.uk, wens@csie.org, robh+dt@kernel.org, mark.rutland@arm.com, devicetree@vger.kernel.org, quentin.schulz@bootlin.com, linux-kernel@vger.kernel.org, clabbe.montjoie@gmail.com, thomas.petazzoni@bootlin.com, linux-arm-kernel@lists.infradead.org List-Id: devicetree@vger.kernel.org On Sun, Mar 18, 2018 at 08:07:15PM +0100, Mylène Josserand wrote: > Hello Mark, > > Please, excuse me for this late answer and thank you for the review! > > On Wed, 7 Mar 2018 12:18:33 +0000 > Marc Zyngier wrote: > > > On 23/02/18 13:37, Mylène Josserand wrote: > > > On Cortex-A7, the CNTVOFF register from arch timer is uninitialized. > > > > Only on A7? Is that specific to your platform? > > I do not really know other Allwinner's platforms about this subject. At > least, the sun9i-a80 which is a Cortex-a15/a7 does not need that but it > is necessary for sun8i-a83t which is a cortex-a7. Maybe, Chen-Yu or > Maxime could help us on it. This is not related to the CPU. On all the other SoCs but the A80 and the A83t, U-Boot will boot the system in HYP, and while switching to non-secure will setup CNTVOFF on the boot CPU. On the A80 and A83t, U-Boot will execute the kernel in secure, it will not switch to non-secure, and CNTVOFF will not be set on the boot CPU. Maxime -- Maxime Ripard, Bootlin (formerly Free Electrons) Embedded Linux and Kernel engineering https://bootlin.com