From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933046Ab2GYNjl (ORCPT ); Wed, 25 Jul 2012 09:39:41 -0400 Received: from wolverine01.qualcomm.com ([199.106.114.254]:57393 "EHLO wolverine01.qualcomm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932917Ab2GYNjk (ORCPT ); Wed, 25 Jul 2012 09:39:40 -0400 X-IronPort-AV: E=McAfee;i="5400,1158,6782"; a="214294096" Message-ID: <500FF71A.7070303@codeaurora.org> Date: Wed, 25 Jul 2012 09:39:38 -0400 From: Christopher Covington User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.13) Gecko/20101208 Thunderbird/3.1.7 MIME-Version: 1.0 To: Catalin Marinas CC: "linux-kernel@vger.kernel.org" , Arnd Bergmann , Will Deacon , Marc Zyngier Subject: Re: [08/36] AArch64: Kernel booting and initialisation References: <1341608777-12982-9-git-send-email-catalin.marinas@arm.com> <500EFAA4.40600@codeaurora.org> <20120725084731.GB11389@arm.com> In-Reply-To: <20120725084731.GB11389@arm.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07/25/2012 04:47 AM, Catalin Marinas wrote: > On Tue, Jul 24, 2012 at 08:42:28PM +0100, Christopher Covington wrote: >> On 01/-10/-28163 02:59 PM, Catalin Marinas wrote: >>> +- Architected timers >>> + CNTFRQ must be programmed with the timer frequency. >>> + If entering the kernel at EL1, CNTHCTL_EL2 must have EL1PCTEN (bit 0) >>> + set where available. >> >> After Marc Zyngier's virtual timer patches come in, will the latter >> requirement only be strictly necessary for kernels wanting to do >> virtualization? > > A kernel is usually entered at EL1 (rather than EL2) if it is a guest. > In this case, the EL1PCTEN bit should have been enabled from the higher > level to give access to the physical counter. Ah right, those patches still use the physical counter for the clocksource and cyclecounter interfaces. Thanks, Christopher -- Employee of Qualcomm Innovation Center, Inc. Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum