From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH 0/19] clean ups on the drivers Date: Tue, 15 May 2007 13:37:30 -0700 (PDT) Message-ID: <20070515.133730.120446537.davem@davemloft.net> References: <1179230056.3685.2.camel@mulgrave.il.steeleye.com> <20070515115748.GA12461@infradead.org> <1179248245.3685.23.camel@mulgrave.il.steeleye.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Return-path: Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:53774 "EHLO sunset.davemloft.net" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1755200AbXEOUhZ (ORCPT ); Tue, 15 May 2007 16:37:25 -0400 In-Reply-To: <1179248245.3685.23.camel@mulgrave.il.steeleye.com> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: James.Bottomley@SteelEye.com Cc: hch@infradead.org, stefanr@s5r6.in-berlin.de, fujita.tomonori@lab.ntt.co.jp, linux-scsi@vger.kernel.org, jens.axboe@oracle.com From: James Bottomley Date: Tue, 15 May 2007 12:57:25 -0400 > It might make sense to put it in lib ... however, I don't think many > architectures have the problems we have ... specifically certain boxes > can have >1 IOMMU, then you really have to know *which* iommu you're > programming. Sparc64 boxes will have this at some point, but what I'm going to do is simply fill in the dev_archdata properly at device scan time. Instead of doing a bus walk up the parent every IOMMU request, why not cache those results in the dev_archdata? That seems to make the most sense. If there is some probing complexity, catch not-setup dev_archdata at the IOMMU request, and slow path into a resolver of some sort.