From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753614Ab2ITNQc (ORCPT ); Thu, 20 Sep 2012 09:16:32 -0400 Received: from smtp.ctxuk.citrix.com ([62.200.22.115]:53036 "EHLO SMTP.EU.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751322Ab2ITNQb (ORCPT ); Thu, 20 Sep 2012 09:16:31 -0400 X-IronPort-AV: E=Sophos;i="4.80,453,1344211200"; d="scan'208";a="14656927" Message-ID: <1348146987.26501.40.camel@zakaz.uk.xensource.com> Subject: Re: [PATCH] arm: introduce a DTS for Xen unprivileged virtual machines From: Ian Campbell To: Stefano Stabellini CC: "linux-kernel@vger.kernel.org" , "xen-devel@lists.xensource.com" , "konrad.wilk@oracle.com" , Pawel Moll , "linux-arm-kernel@lists.infradead.org" Date: Thu, 20 Sep 2012 14:16:27 +0100 In-Reply-To: References: <1348076658-4511-1-git-send-email-stefano.stabellini@eu.citrix.com> <1348136222.26501.19.camel@zakaz.uk.xensource.com> <1348143533.26501.28.camel@zakaz.uk.xensource.com> Organization: Citrix Systems, Inc. Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.4.3-1 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2012-09-20 at 13:39 +0100, Stefano Stabellini wrote: > On Thu, 20 Sep 2012, Ian Campbell wrote: > > > Versatile Express is flexible enough to be a good base for our own > > > virtual machine platform, especially if the maintainers keep an eye on > > > getting everything through DT and not expecting devices just to be there > > > ;-) > > > > Perhaps what we want is a stricter subset of the stuff in mach-vexpress > > then. But if so then this should be expressed both in the DT and in the > > code, not just papered over by declaring things compatible when they are > > not. > > But it is already expressed in the DT, by removing all the device nodes > we don't emulated. And it is already expressed in the code, by fully > discovering peripherals via DT, therefore not trying to initialize > non-present devices. Sorry on second look most of the non-DT stuff is part of the non-DT vexpress support code in the same file. There are some exceptions though: v2m_reset and v2m_power_off don't refer to DT and touch system peripherals directly. v2m_dt_map_io falls back to v2m_io_desc if there is no rs1 node (which I think we don't have?) v2m_clk_init is called from v2m_dt_timer_init (I think you may have fixed this one). > > > > > > > + gic: interrupt-controller@2c001000 { > > > > > + compatible = "arm,cortex-a9-gic"; > > > > > > > > Don't we mean "arm,cortex-a15-gic" here? That's what we actually > > > > provide. I'm not sure how the a9 and a15 differ. > > > > > > The GIC that comes with vexpress is a9 compatible. > > > > The GIC which Xen emulates is the one which matters here though, and > > that is an a15. > > The a15 gic is still a9 compatible. OK to be precise I am going to add > "arm,cortex-a15-gic", but I cannot really remove "arm,cortex-a9-gic". I think A9 is GIC v1 and A15 is GIC v2, with the primary difference being the alignment of the memory mapped registers, but I'm not totally sure of that. A bunch of places do use "arm,cortex-a15-gic", "arm,cortex-a9-gic" so you are probably right that this is the proper answer. Ian.