From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_2 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 32D72C3F2D4 for ; Fri, 28 Feb 2020 13:43:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 064F7246B0 for ; Fri, 28 Feb 2020 13:43:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726525AbgB1NnC (ORCPT ); Fri, 28 Feb 2020 08:43:02 -0500 Received: from foss.arm.com ([217.140.110.172]:38328 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726366AbgB1NnC (ORCPT ); Fri, 28 Feb 2020 08:43:02 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 5A33A31B; Fri, 28 Feb 2020 05:43:01 -0800 (PST) Received: from donnerap.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 7C8153F7B4; Fri, 28 Feb 2020 05:42:57 -0800 (PST) Date: Fri, 28 Feb 2020 13:42:54 +0000 From: Andre Przywara To: Will Deacon List-Id: Cc: Rob Herring , "moderated list:ARM/FREESCALE IMX / MXC ARM ARCHITECTURE" , "linux-kernel@vger.kernel.org" , soc@kernel.org, Robert Richter , Jon Loeliger , Alexander Graf , Matthias Brugger , Mark Langsdorf , Alex Williamson , Borislav Petkov , Cornelia Huck , Daniel Lezcano , "David S. Miller" , devicetree@vger.kernel.org, Eric Auger , Linux IOMMU , James Morse , Jens Axboe , Joerg Roedel , kvm@vger.kernel.org, linux-clk , linux-edac , "open list:LIBATA SUBSYSTEM (Serial and Parallel ATA drivers)" , "open list:THERMAL" , Mauro Carvalho Chehab , netdev , "Rafael J. Wysocki" , Robin Murphy , Stephen Boyd , Tony Luck , Viresh Kumar Subject: Re: [RFC PATCH 06/11] iommu: arm-smmu: Remove Calxeda secure mode quirk Message-ID: <20200228134254.03fc5e1b@donnerap.cambridge.arm.com> In-Reply-To: <20200228105024.GC2395@willie-the-truck> References: <20200218171321.30990-1-robh@kernel.org> <20200218171321.30990-7-robh@kernel.org> <20200218172000.GF1133@willie-the-truck> <20200228100446.GA2395@willie-the-truck> <20200228102556.1dde016e@donnerap.cambridge.arm.com> <20200228105024.GC2395@willie-the-truck> Organization: ARM X-Mailer: Claws Mail 3.17.3 (GTK+ 2.24.32; aarch64-unknown-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-edac-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-edac@vger.kernel.org On Fri, 28 Feb 2020 10:50:25 +0000 Will Deacon wrote: > On Fri, Feb 28, 2020 at 10:25:56AM +0000, Andre Przywara wrote: > > On Fri, 28 Feb 2020 10:04:47 +0000 > > Will Deacon wrote: > > > > Hi, > > > > > On Tue, Feb 25, 2020 at 04:01:54PM -0600, Rob Herring wrote: > > > > On Tue, Feb 18, 2020 at 11:20 AM Will Deacon wrote: > > > > > > > > > > On Tue, Feb 18, 2020 at 11:13:16AM -0600, Rob Herring wrote: > > > > > > Cc: Will Deacon > > > > > > Cc: Robin Murphy > > > > > > Cc: Joerg Roedel > > > > > > Cc: iommu@lists.linux-foundation.org > > > > > > Signed-off-by: Rob Herring > > > > > > --- > > > > > > Do not apply yet. > > > > > > > > > > Pleeeeease? ;) > > > > > > > > > > > drivers/iommu/arm-smmu-impl.c | 43 ----------------------------------- > > > > > > 1 file changed, 43 deletions(-) > > > > > > > > > > Yes, I'm happy to get rid of this. Sadly, I don't think we can remove > > > > > anything from 'struct arm_smmu_impl' because most implementations fall > > > > > just short of perfect. > > > > > > > > > > Anyway, let me know when I can push the button and I'll queue this in > > > > > the arm-smmu tree. > > > > > > > > Seems we're leaving the platform support for now, but I think we never > > > > actually enabled SMMU support. It's not in the dts either in mainline > > > > nor the version I have which should be close to what shipped in > > > > firmware. So as long as Andre agrees, this one is good to apply. > > > > > > Andre? Can I queue this one for 5.7, please? > > > > I was wondering how much of a pain it is to keep it in? AFAICS there are > > other users of the "impl" indirection. If those goes away, I would be > > happy to let Calxeda go. > > The impl stuff is new, so we'll keep it around. The concern is more about > testing (see below). > > > But Eric had the magic DT nodes to get the SMMU working, and I used that > > before, with updating the DT either on flash or dynamically via U-Boot. > > What did you actually use the SMMU for, though? The > 'arm_iommu_create_mapping()' interface isn't widely used and, given that > highbank doesn't support KVM, the use-cases for VFIO are pretty limited > too. AFAIK Highbank doesn't have the SMMU, probably mostly for that reason. I have a DT snippet for Midway, and that puts the MMIO base at ~36GB, which is not possible on Highbank. So I think that the quirk is really meant and needed for Midway. > > So I don't know exactly *how* desperate you are with removing this, or if > > there are other reasons than "negative diffstat", but if possible I would > > like to keep it in. > > It's more that we *do* make quite a lot of changes to the arm-smmu driver > and it's never tested with this quirk. If you're stepping up to run smmu > tests on my queue for each release on highbank, then great, but otherwise > I'd rather not carry the code for fun. The change in diffstat is minimal > (we're going to need to hooks for nvidia, who broke things in a different > way). I am about to set up some more sophisticated testing, and will include some SMMU bits in it. Cheers, Andre. > Also, since the hooks aren't going away, if you /do/ end up using the SMMU > in future, then we could re-add the driver quirk without any fuss. > > Will