From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933587AbcKNQUv (ORCPT ); Mon, 14 Nov 2016 11:20:51 -0500 Received: from 8bytes.org ([81.169.241.247]:59219 "EHLO theia.8bytes.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932583AbcKNQUs (ORCPT ); Mon, 14 Nov 2016 11:20:48 -0500 Date: Mon, 14 Nov 2016 17:20:37 +0100 From: Joerg Roedel To: Auger Eric Cc: drjones@redhat.com, alex.williamson@redhat.com, jason@lakedaemon.net, kvm@vger.kernel.org, marc.zyngier@arm.com, punit.agrawal@arm.com, will.deacon@arm.com, linux-kernel@vger.kernel.org, diana.craciun@nxp.com, iommu@lists.linux-foundation.org, pranav.sawargaonkar@gmail.com, christoffer.dall@linaro.org, tglx@linutronix.de, robin.murphy@arm.com, linux-arm-kernel@lists.infradead.org, eric.auger.pro@gmail.com Subject: Re: [RFC v2 8/8] iommu/arm-smmu: implement add_reserved_regions callback Message-ID: <20161114162037.GC14829@8bytes.org> References: <20161110154606.GH2078@8bytes.org> <04ed9694-707d-260b-70c6-f367d292ceca@redhat.com> <20161110161331.GJ2078@8bytes.org> <20161111114223.GP2078@8bytes.org> <79da09b8-ac1e-cebf-5393-7d67f002b3e3@redhat.com> <20161111162211.GU2078@8bytes.org> <634ac375-3507-6926-164f-e67f7c798c98@redhat.com> <20161114153149.GY2078@8bytes.org> <295feefe-014b-5669-7f5a-e04b09ba3454@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <295feefe-014b-5669-7f5a-e04b09ba3454@redhat.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Nov 14, 2016 at 05:08:16PM +0100, Auger Eric wrote: > There are potentially several MSI doorbell physical pages in the SOC > that are accessed through the IOMMU (translated). Each of those must > have a corresponding IOVA and IOVA/PA mapping programmed in the IOMMU. > Else MSI will fault. > > - step 1 was to define a usable IOVA range for MSI mapping. So now we > decided the base address and size would be hardcoded for ARM. The > get_dm_region can be used to retrieve that hardcoded region. > - Step2 is to allocate IOVAs within that range and map then for each of > those MSI doorbells. This is done in the MSI controller compose() callback. > > I hope I succeeded in clarifying this time. > > Robin sent today a new version of its cookie think using a dummy > allocator. I am currently integrating it. Okay, I understand. A simple bitmap-allocator would probably be sufficient, and doesn't have the overhead the iova allocator has. About how many pages are we talking here? Joerg