Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755152AbWKMQhn (ORCPT ); Mon, 13 Nov 2006 11:37:43 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755154AbWKMQhn (ORCPT ); Mon, 13 Nov 2006 11:37:43 -0500 Received: from mtagate1.de.ibm.com ([195.212.29.150]:5578 "EHLO mtagate1.de.ibm.com") by vger.kernel.org with ESMTP id S1755152AbWKMQhm (ORCPT ); Mon, 13 Nov 2006 11:37:42 -0500 In-Reply-To: <17748.15442.906060.210242@cargo.ozlabs.ibm.com> Subject: Re: [openib-general] [PATCH 2.6.19 2/4] ehca: hcp_phyp.c: correct page mapping in 64k page mode To: Paul Mackerras Cc: linux-kernel@vger.kernel.org, linuxppc-dev@ozlabs.org, openib-general@openib.org, openib-general-bounces@openib.org, "Roland Dreier" X-Mailer: Lotus Notes Release 7.0 HF277 June 21, 2006 Message-ID: From: Christoph Raisch Date: Mon, 13 Nov 2006 17:40:52 +0100 X-MIMETrack: Serialize by Router on D12ML067/12/M/IBM(Release 6.5.5HF607 | June 26, 2006) at 13/11/2006 17:40:53 MIME-Version: 1.0 Content-type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1201 Lines: 38 > Christoph Raisch writes: > > > The patch is needed. We've seen it on the real system. We did fix it on the > > real system. > > I disagree that the ioremap change is needed. > > > ...and it conforms to theory... although theory is a bit confusing here. > > > > let me try to summarize: > > ioremap checks for 64k boundary (actually page boundary) > > Actually, ioremap itself already does the calculations that your patch > adds - that is, it generates the offset within the page and the > physical address of the start of the page, does the mapping using the > latter, then adds on the offset to the virtual address of the page and > returns that. Paul, you are right. The calculation is done in your code already. We can't reproduce the problem anymore on latest kernel. Was this calculation there in ioremap right from the start with 64k on POWER or added later on? So Roland, feel free to ignore that line where we do the calculation. > > Paul. - 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/