From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Roedel, Joerg" Subject: Re: [RFC 0/6] iommu: generic api migration and grouping Date: Mon, 6 Jun 2011 12:09:51 +0200 Message-ID: <20110606100950.GC30762@amd.com> References: <1307053663-24572-1-git-send-email-ohad@wizery.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Return-path: Content-Disposition: inline In-Reply-To: <1307053663-24572-1-git-send-email-ohad@wizery.com> Sender: linux-media-owner@vger.kernel.org To: Ohad Ben-Cohen Cc: "linux-media@vger.kernel.org" , "linux-omap@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "laurent.pinchart@ideasonboard.com" , "Hiroshi.DOYU@nokia.com" , "arnd@arndb.de" , "davidb@codeaurora.org" List-Id: linux-omap@vger.kernel.org Hi, On Thu, Jun 02, 2011 at 06:27:37PM -0400, Ohad Ben-Cohen wrote: > First stab at iommu consolidation: > > - Migrate OMAP's iommu driver to the generic iommu API. With this in hand, > users can now start using the generic iommu layer instead of calling > omap-specific iommu API. > > New code that requires functionality missing from the generic iommu api, > will add that functionality in the generic framework (e.g. adding framework > awareness to multi page sizes, supported by the underlying hardware, will > avoid the otherwise-inevitable code duplication when mapping a memory > region). The IOMMU-API already supports multiple page-sizes. See the 'order'-parameter of the map/unmap functions. > Further generalizing of iovmm strongly depends on our broader plans for > providing a generic virtual memory manager and allocation framework > (which, as discussed, should be separated from a specific mapper). The generic vmm for DMA is called DMA-API :) Any reason for not using that (those reasons should be fixed)? > iovmm has a mainline user: omap3isp, and therefore must be maintained, > but new potential users will either have to generalize it, or come up > with a different generic framework that will replace it. Moving to the DMA-API should be considered here. If it is too much work iovmm can stay for a while, but the goal should be to get rid of it and only use the DMA-API. > - Create a dedicated iommu drivers folder (and put the base iommu code there) Very good idea. Joerg P.S.: Please also Cc the iommu-list (iommu@lists.linux-foundation.org) in the future for IOMMU related patches. -- 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 From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joerg.Roedel@amd.com (Roedel, Joerg) Date: Mon, 6 Jun 2011 12:09:51 +0200 Subject: [RFC 0/6] iommu: generic api migration and grouping In-Reply-To: <1307053663-24572-1-git-send-email-ohad@wizery.com> References: <1307053663-24572-1-git-send-email-ohad@wizery.com> Message-ID: <20110606100950.GC30762@amd.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi, On Thu, Jun 02, 2011 at 06:27:37PM -0400, Ohad Ben-Cohen wrote: > First stab at iommu consolidation: > > - Migrate OMAP's iommu driver to the generic iommu API. With this in hand, > users can now start using the generic iommu layer instead of calling > omap-specific iommu API. > > New code that requires functionality missing from the generic iommu api, > will add that functionality in the generic framework (e.g. adding framework > awareness to multi page sizes, supported by the underlying hardware, will > avoid the otherwise-inevitable code duplication when mapping a memory > region). The IOMMU-API already supports multiple page-sizes. See the 'order'-parameter of the map/unmap functions. > Further generalizing of iovmm strongly depends on our broader plans for > providing a generic virtual memory manager and allocation framework > (which, as discussed, should be separated from a specific mapper). The generic vmm for DMA is called DMA-API :) Any reason for not using that (those reasons should be fixed)? > iovmm has a mainline user: omap3isp, and therefore must be maintained, > but new potential users will either have to generalize it, or come up > with a different generic framework that will replace it. Moving to the DMA-API should be considered here. If it is too much work iovmm can stay for a while, but the goal should be to get rid of it and only use the DMA-API. > - Create a dedicated iommu drivers folder (and put the base iommu code there) Very good idea. Joerg P.S.: Please also Cc the iommu-list (iommu at lists.linux-foundation.org) in the future for IOMMU related patches. -- 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