From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1764768AbXGPNrk (ORCPT ); Mon, 16 Jul 2007 09:47:40 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757474AbXGPNrb (ORCPT ); Mon, 16 Jul 2007 09:47:31 -0400 Received: from hancock.steeleye.com ([71.30.118.248]:47924 "EHLO hancock.sc.steeleye.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1756854AbXGPNra (ORCPT ); Mon, 16 Jul 2007 09:47:30 -0400 Subject: Re: [patch 5/6] ps3: BD/DVD/CD-ROM Storage Driver From: James Bottomley To: Jens Axboe Cc: Geert Uytterhoeven , Arnd Bergmann , linux-scsi@vger.kernel.org, Linux Kernel Development , Alessandro Rubini , Linux/PPC Development , Paul Mackerras In-Reply-To: <20070716121649.GI5195@kernel.dk> References: <20070704132212.726923000@pademelon.sonytel.be> <1184335333.3402.20.camel@localhost.localdomain> <200707131619.54898.arnd@arndb.de> <1184340528.3402.32.camel@localhost.localdomain> <20070716121649.GI5195@kernel.dk> Content-Type: text/plain Date: Mon, 16 Jul 2007 08:47:23 -0500 Message-Id: <1184593643.3447.9.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Evolution 2.10.2 (2.10.2-3.fc7) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2007-07-16 at 14:16 +0200, Jens Axboe wrote: > On Mon, Jul 16 2007, Geert Uytterhoeven wrote: > > On Fri, 13 Jul 2007, Geert Uytterhoeven wrote: > > > Ah, that explains it. flush_dcache_page() is used in some drivers. > > > I'll update my patches. Thanks for the comments! > > > > Does this look OK? > > - Replaced KM_USER0 by KM_IRQ0 (all routines are either called from an > > interrupt handler, from .request_fn (ps3disk), or from .queuecommand > > (ps3rom)) > > That looks good. > > > - Add a call to flush_kernel_dcache_page() in routines that write to buffers > > Hmm, I would have thought a flush_dcache_page() would be more > appropriate, the backing could be page cache pages. No ... that was the point of flush_kernel_dcache_page(). The page in question is page cache backed and contains user mappings. However, the block layer has already done a flush_dcache_page() in get_user_pages() and the user shouldn't be touching memory under I/O (unless they want self induced aliasing problems) so we're free to assume all the user cachelines are purged, hence all we have to do is flush the kernel alias to bring the page up to date and make the users see it correctly. James