Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757320Ab3DYKCu (ORCPT ); Thu, 25 Apr 2013 06:02:50 -0400 Received: from relay1.sgi.com ([192.48.179.29]:48238 "EHLO relay.sgi.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757260Ab3DYKCs (ORCPT ); Thu, 25 Apr 2013 06:02:48 -0400 Date: Thu, 25 Apr 2013 05:02:46 -0500 From: Robin Holt To: Jean Delvare Cc: "Luck, Tony" , DuanZhenzhong , Andrew Morton , linux-kernel , "Yu, Fenghua" Subject: Re: memcpy_fromio in dmi_scan.c Message-ID: <20130425100246.GR3672@sgi.com> References: <1366636689.4503.35.camel@chaos.site> <5175FF0F.9050206@oracle.com> <1366702122.4667.11.camel@chaos.site> <3908561D78D1C84285E8C5FCA982C28F1EA52ED3@ORSMSX104.amr.corp.intel.com> <1366831328.4618.476.camel@chaos.site> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1366831328.4618.476.camel@chaos.site> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1289 Lines: 27 On Wed, Apr 24, 2013 at 09:22:08PM +0200, Jean Delvare wrote: > Hi Tony, > > Thanks for stepping in. > > Le Tuesday 23 April 2013 ? 22:00 +0000, Luck, Tony a ?crit : > > > I don't have much knowledge about IA64 either. All I see is that while > > > x86 implements memcpy_fromio() with memcpy [1], ia64 implements it with > > > readb [2]. There must be a reason for that, and I can only suppose that > > > memcpy on __iomem pointers doesn't work on IA64. If memcpy doesn't work > > > then I can't see memcmp working. > > > > On most platforms readb() just ends up doing a regular dereference of the > > address ... so I'd expect that memcmp would work just fine. The exception > > is the old SGI sn2 which end up calling ___sn_readb() ... which does something > > weird with sn_dma_flush() after doing the dereference of *addr. I don't sn_dma_flush has a good description at the beginning of it. It is only related to activity on PCI attached devices and a memcmp should be fine. It must be that our prom produces a bad DMI table. Robin -- 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/