From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754856AbYIWClh (ORCPT ); Mon, 22 Sep 2008 22:41:37 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754134AbYIWCl2 (ORCPT ); Mon, 22 Sep 2008 22:41:28 -0400 Received: from gw.goop.org ([64.81.55.164]:39553 "EHLO mail.goop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753938AbYIWCl1 (ORCPT ); Mon, 22 Sep 2008 22:41:27 -0400 Message-ID: <48D85758.7080303@goop.org> Date: Mon, 22 Sep 2008 19:41:28 -0700 From: Jeremy Fitzhardinge User-Agent: Thunderbird 2.0.0.16 (X11/20080723) MIME-Version: 1.0 To: Joerg Roedel CC: Arjan van de Ven , linux-kernel@vger.kernel.org, kvm@vger.kernel.org, iommu@lists.linux-foundation.org, David Woodhouse , Muli Ben-Yehuda , Amit Shah , Ingo Molnar , FUJITA Tomonori Subject: Re: [PATCH 0/9][RFC] stackable dma_ops for x86 References: <1222107681-8185-1-git-send-email-joerg.roedel@amd.com> <20080922113619.5075e7e4@infradead.org> <20080922183944.GJ24392@amd.com> In-Reply-To: <20080922183944.GJ24392@amd.com> X-Enigmail-Version: 0.95.7 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Joerg Roedel wrote: > Its implemented using the per-device dma-ops already there. With this > patches there is a list of available dma_ops implementations which are > asked in a particular order if they can handle the device. The first > implementation which returns true is assigned to the device as the > per-device dma_ops structure. > > (Hmm, maybe the name stackable is misleading, is "dma_ops multiplexing" > better?) Is per-device the right level? Wouldn't per-bus make more sense? How does a dma_ops implementation "know" whether it can handle a particular device? (I haven't had a chance to read the patches yet.) J