From mboxrd@z Thu Jan 1 00:00:00 1970 From: FUJITA Tomonori Subject: Re: [PATCH 0/5] fix iommu sg list merge problem Date: Wed, 26 Sep 2007 23:34:49 +0900 Message-ID: <20070925200025O.tomof@acm.org> References: <20070925142141N.tomof@acm.org> <20070926100221.GW4239@rhun.haifa.ibm.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Return-path: Received: from mo10.iij4u.or.jp ([210.138.174.78]:47149 "EHLO mo10.iij4u.or.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751790AbXIZOgK (ORCPT ); Wed, 26 Sep 2007 10:36:10 -0400 In-Reply-To: <20070926100221.GW4239@rhun.haifa.ibm.com> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: muli@il.ibm.com Cc: tomof@acm.org, James.Bottomley@SteelEye.com, jens.axboe@oracle.com, hch@infradead.org, jeff@garzik.org, gregkh@suse.de, hare@suse.de, linux-scsi@vger.kernel.org, fujita.tomonori@lab.ntt.co.jp On Wed, 26 Sep 2007 12:02:21 +0200 Muli Ben-Yehuda wrote: > On Wed, Sep 26, 2007 at 05:57:57PM +0900, FUJITA Tomonori wrote: > > > iommu code merges sg lists without considering lld's restrictions so > > some llds need a workaround to split sg lists again. This patchset > > fixes iommu to handle lld's max segment size limit properly. > > The patches look reasonable to me. > > > This patchset includes only the x86_64 iommu patch > > There are multiple x86-64 IOMMUs, but only GART is in-tree and > supports merging. > > > but my git tree includes x86_64, ppc, ia64, parisc, and alpha > > patches. As far as I know, thye are all the iommu code that merges > > sg lists. The iommu patchse are only compile tested. > > > > > > git://git.kernel.org/pub/scm/linux/kernel/git/tomo/linux-2.6-bidi.git iommu > > Do you think it will be possible to abstract the merging code into > common code, rather than duplicating it for every IOMMU? Yeah, I thought about it and it's possible (but not so easy). parisc has IOMMU merging helper code and two parisc IOMMUs use it. ia64 sba_iommu is almost identical to parisc code. x86_64 gart, power, and alpha do in their own way. But I think that we can merging helper code useful for all. I'll see what we can have after fixing the mering problem.