Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933127Ab3CEDsS (ORCPT ); Mon, 4 Mar 2013 22:48:18 -0500 Received: from smtp02.citrix.com ([66.165.176.63]:35597 "EHLO SMTP02.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932843Ab3CEDsO (ORCPT ); Mon, 4 Mar 2013 22:48:14 -0500 X-IronPort-AV: E=Sophos;i="4.84,784,1355097600"; d="scan'208";a="10565635" Message-ID: <1362455124.8941.19.camel@hastur.hellion.org.uk> Subject: Re: [PATCH LINUX v5] xen: event channel arrays are xen_ulong_t and not unsigned long From: Ian Campbell To: Will Deacon CC: Rob Herring , "xen-devel@lists.xen.org" , "Keir (Xen.org)" , "Stefano Stabellini" , Konrad Rzeszutek Wilk , "Tim (Xen.org)" , "linux-kernel@vger.kernel.org" , Jan Beulich , "linux-arm-kernel@lists.infradead.org" , Nicolas Pitre Date: Tue, 5 Mar 2013 03:45:24 +0000 In-Reply-To: <20130305030436.GA18040@mudshark.cambridge.arm.com> References: <1361285327.1051.115.camel@zakaz.uk.xensource.com> <1361360886-2956-1-git-send-email-ian.campbell@citrix.com> <51340ACD.70904@gmail.com> <20130305030436.GA18040@mudshark.cambridge.arm.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.4.4-2 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: 2238 Lines: 61 On Tue, 2013-03-05 at 03:04 +0000, Will Deacon wrote: > Hi guys, > > On Mon, Mar 04, 2013 at 02:45:33AM +0000, Rob Herring wrote: > > On 02/20/2013 05:48 AM, Ian Campbell wrote: > > > On ARM we want these to be the same size on 32- and 64-bit. > > > > > > This is an ABI change on ARM. X86 does not change. > > > > > > Signed-off-by: Ian Campbell > > > Cc: Jan Beulich > > > Cc: Keir (Xen.org) > > > Cc: Tim Deegan > > > Cc: Stefano Stabellini > > > Cc: linux-arm-kernel@lists.infradead.org > > > Cc: xen-devel@lists.xen.org > > > Cc: Konrad Rzeszutek Wilk > > [...] > > > I'm seeing some some build failures on randconfig builds with this change: > > > > /tmp/ccJaIZOW.s: Assembler messages: > > /tmp/ccJaIZOW.s:831: Error: even register required -- `ldrexd r5,r6,[r4]' > > > > This is with ubuntu 12.04 cross compiler (gcc version 4.6.3 > > (Ubuntu/Linaro 4.6.3-1ubuntu5)). > > > > This register restriction is on ARM, but not Thumb builds. Comparing > > this to atomic64_cmpxchg, I don't see how to fix this. Perhaps Will or > > Nico have thoughts. > > [...] > > > > + asm volatile("@ xchg_xen_ulong\n" > > > + "1: ldrexd %0, %H0, [%3]\n" > > > + " strexd %1, %2, %H2, [%3]\n" > > > + " teq %1, #0\n" > > > + " bne 1b" > > > + : "=&r" (oldval), "=&r" (tmp) > > > + : "r" (val), "r" (ptr) > > > + : "memory", "cc"); > > I also can't immediately see why GCC would allocate oldval to an odd base > register. Can you share your .config please? I fixed something along these lines before v5 of this patch, although I must confess I don't recall what it was that I changed (and looking at the older versions of the patch isn't giving me any clues). I can't reproduce it now though :-( I'm using the 4.6.3 cross compiler from kernel.org: ftp://ftp.kernel.org/pub/tools/crosstool/files/bin/x86_64/4.6.3/ 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/