Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754908Ab2JIQKk (ORCPT ); Tue, 9 Oct 2012 12:10:40 -0400 Received: from smtp.ctxuk.citrix.com ([62.200.22.115]:41462 "EHLO SMTP.EU.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751407Ab2JIQKi (ORCPT ); Tue, 9 Oct 2012 12:10:38 -0400 X-IronPort-AV: E=Sophos;i="4.80,561,1344211200"; d="scan'208";a="15044977" Message-ID: <1349799035.21847.222.camel@zakaz.uk.xensource.com> Subject: Re: [Xen-devel] [PATCH 5/9] ARM: Xen: fix initial build problems: From: Ian Campbell To: Arnd Bergmann CC: Russell King , Jeremy Fitzhardinge , "xen-devel@lists.xensource.com" , Konrad Rzeszutek Wilk , Stefano Stabellini , "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" Date: Tue, 9 Oct 2012 17:10:35 +0100 In-Reply-To: <201210091539.46274.arnd@arndb.de> References: <1349796183-30648-1-git-send-email-arnd@arndb.de> <1349796183-30648-6-git-send-email-arnd@arndb.de> <1349796958.21847.219.camel@zakaz.uk.xensource.com> <201210091539.46274.arnd@arndb.de> 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 Content-Length: 1252 Lines: 33 On Tue, 2012-10-09 at 16:39 +0100, Arnd Bergmann wrote: > On Tuesday 09 October 2012, Ian Campbell wrote: > > > * The tmem hypercall is not available on ARM > > > > > > * ARMv6 does not support cmpxchg on 16-bit words that are used in the > > > > missing the end of this sentence? > > Right, I meant to say > > * ARMv6 does not support cmpxchg on 16-bit words that are used in the > Xen grant table code, so we must ensure that Xen support is only built > on ARMv7-only kernels not combined ARMv6/v7 kernels. > > This should be fixed differently in the future. Is this is a build time failure because gcc/gas/etc refuses to generate these instructions if it is configured for v6? I ask because if it is only a runtime issue then we can reason that if we are running Xen specific grant table code, then we must be running on Xen and therefore must necessarily be running on a v7 (because Xen only support v7+virt extensions) even if the kernel happens to be capable of running on v6 too. Ian. -- 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/