From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753495Ab1IZMW0 (ORCPT ); Mon, 26 Sep 2011 08:22:26 -0400 Received: from va3ehsobe003.messaging.microsoft.com ([216.32.180.13]:14725 "EHLO VA3EHSOBE003.bigfish.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753205Ab1IZMWZ convert rfc822-to-8bit (ORCPT ); Mon, 26 Sep 2011 08:22:25 -0400 X-SpamScore: -21 X-BigFish: VPS-21(zz9371K1432N98dKzz1202hzz15d4R8275bhz32i668h839h62h) X-Spam-TCS-SCL: 1:0 X-Forefront-Antispam-Report: CIP:163.181.249.108;KIP:(null);UIP:(null);IPVD:NLI;H:ausb3twp01.amd.com;RD:none;EFVD:NLI X-WSS-ID: 0LS4QD1-01-5SH-02 X-M-MSG: Date: Mon, 26 Sep 2011 14:22:14 +0200 From: "Roedel, Joerg" To: Ohad Ben-Cohen CC: "iommu@lists.linux-foundation.org" , Greg Kroah-Hartman , Alex Williamson , David Woodhouse , David Brown , "joro@8bytes.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH 08/10] iommu/omap: Use bus_set_iommu instead of register_iommu Message-ID: <20110926122213.GC2138@amd.com> References: <1316792756-3395-1-git-send-email-joerg.roedel@amd.com> <1316792756-3395-9-git-send-email-joerg.roedel@amd.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Content-Transfer-Encoding: 8BIT X-OriginatorOrg: amd.com Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Sep 26, 2011 at 03:09:58AM -0400, Ohad Ben-Cohen wrote: > On Fri, Sep 23, 2011 at 6:45 PM, Joerg Roedel wrote: > > -       register_iommu(&omap_iommu_ops); > > +       bus_set_iommu(&platform_bus_type, &omap_iommu_ops); > > I'm not sure it makes a lot of sense to bind the iommu ops to the platform bus. > > Unlike the pci bus, the platform bus is not really a hardware bus: > it's some kind of a catch-all pseudo bus which is mostly used to to > describe a collection of autonomous peripherals on an SoC. > > As a result, IOMMU users on an SoC might actually not belong to the > platform bus. That is interesting. What bus do these IOMMU users you talk about belong to? Is it a seperate bus that originates from a platform device? in that case the situation sounds a little bit like with USB on x86. The usb controlers are PCI devices and DMA handles are allocated using the pci_dev of the controler and not the usb_device. Regards, Joerg -- AMD Operating System Research Center Advanced Micro Devices GmbH Einsteinring 24 85609 Dornach General Managers: Alberto Bozzo, Andrew Bowd Registration: Dornach, Landkr. Muenchen; Registerger. Muenchen, HRB Nr. 43632