From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joerg Roedel Subject: Re: [PATCH v5 11/18] iommu: exynos: remove useless device_add/remove callbacks Date: Mon, 26 Jan 2015 14:47:01 +0100 Message-ID: <20150126134701.GH30345@8bytes.org> References: <1422028288-891-1-git-send-email-m.szyprowski@samsung.com> <2829552.kzfCU5HyxQ@avalon> <20150126110059.GC30345@8bytes.org> <1589480.9kxdoXKkuz@avalon> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <1589480.9kxdoXKkuz@avalon> Sender: linux-samsung-soc-owner@vger.kernel.org To: Laurent Pinchart Cc: Marek Szyprowski , iommu@lists.linux-foundation.org, linux-samsung-soc@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linaro-mm-sig@lists.linaro.org, Arnd Bergmann , Shaik Ameer Basha , Cho KyongHo , Thierry Reding , Olof Johansson , Rob Herring , Will Deacon , David Wodhouse , Inki Dae , Kukjin Kim , Tomasz Figa , Kyungmin Park , Joonyoung Shim , Seung-Woo Kim List-Id: iommu@lists.linux-foundation.org Hi Laurent, On Mon, Jan 26, 2015 at 03:03:57PM +0200, Laurent Pinchart wrote: > On Monday 26 January 2015 12:00:59 Joerg Roedel wrote: > > My plan is to make IOMMU groups mandatory. I am currently preparing and > > RFC patch-set to introduce default-domains (which will be per group). So > > when all IOMMU drivers are converted to make use of default domains the > > iommu groups will be mandatory. > > Could the default domain policy be configured by the IOMMU driver ? The ipmmu- > vmsa driver supports four domains only, and serves up to 32 masters, with one > group per master. A default of one domain per group wouldn't be usable. I guess this limitation is a property of the iommu hardware. I currently have no support for this in the patch-set, but I think it is easy (and the best way) to support a model where we have only one default domain for all groups. This is not in the patch set right now, but will be added at some point. Joerg