Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756417Ab3DXSNV (ORCPT ); Wed, 24 Apr 2013 14:13:21 -0400 Received: from smtp.citrix.com ([66.165.176.89]:33676 "EHLO SMTP.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755277Ab3DXSNT (ORCPT ); Wed, 24 Apr 2013 14:13:19 -0400 X-IronPort-AV: E=Sophos;i="4.87,545,1363132800"; d="scan'208";a="21362095" Date: Wed, 24 Apr 2013 19:13:15 +0100 From: Stefano Stabellini X-X-Sender: sstabellini@kaball.uk.xensource.com To: Nicolas Pitre CC: Ian Campbell , Stefano Stabellini , "xen-devel@lists.xensource.com" , Russell King - ARM Linux , "arnd@arndb.de" , "marc.zyngier@arm.com" , "will.deacon@arm.com" , "linux-kernel@vger.kernel.org" , "rob.herring@calxeda.com" , "linux-arm-kernel@lists.infradead.org" Subject: Re: [Xen-devel] [PATCH v6 1/4] arm: introduce psci_smp_ops In-Reply-To: Message-ID: References: <1365167495-18508-1-git-send-email-stefano.stabellini@eu.citrix.com> <20130418161341.GB14496@n2100.arm.linux.org.uk> <1366388166.29403.2.camel@dagon.hellion.org.uk> <1366644069.20256.8.camel@zakaz.uk.xensource.com> User-Agent: Alpine 2.02 (DEB 1266 2009-07-14) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1305 Lines: 27 On Mon, 22 Apr 2013, Nicolas Pitre wrote: > > I think the key thing that non-Xen folks aren't aware of is that > > although Xen passes the majority of the underlying hardware to the dom0 > > kernel to manage one of the few things it does not expose to guests > > (where "guests" includes dom0) is the SMP topology of the underlying system. > > I suspect it is unlikely to pass on the DT information about the CCI > either. Which means that, in the case that started this thread, the > smp_init function needed by MCPM will simply return false and the next > priority in the list i.e. plain PSCI will be initialized instead. > > I don't forsee the need to poke at the hardware directly within > ->smp_init, not since everything is moving to DT now. > > Sure there are ways to screw up Xen support from within this hook, but > that can be achieved in many other places. Will Xen take over every > possible hooks in the kernel to prevent that from happening? > > So please let's not cry wolf needlessly. OK, you convinced me :-) I'll drop the patch. -- 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/