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=-0.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 1C195C43613 for ; Mon, 24 Jun 2019 12:55:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E548320679 for ; Mon, 24 Jun 2019 12:55:09 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="RO8plrW1" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728556AbfFXMzI (ORCPT ); Mon, 24 Jun 2019 08:55:08 -0400 Received: from mail-lf1-f65.google.com ([209.85.167.65]:46782 "EHLO mail-lf1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727327AbfFXMzI (ORCPT ); Mon, 24 Jun 2019 08:55:08 -0400 Received: by mail-lf1-f65.google.com with SMTP id z15so9901367lfh.13; Mon, 24 Jun 2019 05:55:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=WNEPAJU0PKDjx+XnMY/T0wpxzKSr9Cr3EplpOoCn4Mg=; b=RO8plrW1jTvcIU9jaiUr7gbc5+mACH0QXHLY3czL8SgaIhkmOlLNLRThMiAUSqB5Ly 8Z0H2FubYRIdzrxk5ZZKDi0MOMaGgn1Cy6DM5Tz5+bBIcstMxY7a0zn93hYlohOi0cx+ dRaClftcITthbkuf+GMufHq115LKWsPXfIEUGwLbRij2EgfffrDvbyyJjL0tVAxcFR8E ABEkxVK/PMW83c2/h7KNA7UkXGfLNPIwfswHio2wX8A0cwQhFG882iRx/C0v6KbAzR8U +MFGbBVbfaGX2wbnqHofSk2s1nDCMO6eNmZ/C42BFo9Ak8BkTwY5yq9hUB6/b/pEabsk Tj3w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=WNEPAJU0PKDjx+XnMY/T0wpxzKSr9Cr3EplpOoCn4Mg=; b=TWdgT8Brice8h6AD9YrvEUaF9jrKBFQEYuMTBo4/JmkSQ1CG1ciIE3eyuQPIvTK12U I/jDL8Tqc7DqE6zShX/UeEj8w7gvdi01UyIZhuWU1bhPBzUrXiLRv5ESLEMJN0tQCRfD uegSYlg1B7WwcosUTj/+V5fVp0hIpKY1ECE8wBop6lh2eGMK+mHpqxY8h6hMY66hY7iF AUrHGHQ92qkc/HQ022wY9Z5EM3kD4mJIfgmzI3rOH547W3pbNqmyha/lO810ei3dOmvZ IPrdrO8+vMfb8vzFvyqJjMg1r8Na0m1mjW//Wt8Cn2UvKJ9n7xnJBYjA0WPVEBGxujfa yyVA== X-Gm-Message-State: APjAAAULvWzz1ZZXgG2wXZVBUKfY0X6GsKrDwup4xQzJ2MBhnVPsD22G 1bAY9PuXiuCO84VU0DkaoBurslu8 X-Google-Smtp-Source: APXvYqzSDGrndyCxLDg8GGelDuwS8V7x7tQBjK5jsA9NOeIRgsbr70QnRs0ab8nFHEci1xRTIgnoYA== X-Received: by 2002:a19:ca0e:: with SMTP id a14mr20824806lfg.19.1561380906306; Mon, 24 Jun 2019 05:55:06 -0700 (PDT) Received: from [192.168.2.145] (ppp91-79-162-197.pppoe.mtu-net.ru. [91.79.162.197]) by smtp.googlemail.com with ESMTPSA id u13sm1568415lfl.61.2019.06.24.05.55.05 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 24 Jun 2019 05:55:05 -0700 (PDT) Subject: Re: [PATCH v1 1/3] gpu: host1x: Remove implicit IOMMU backing on client's registration To: Christoph Hellwig Cc: Thierry Reding , dri-devel@lists.freedesktop.org, linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org References: <20190623173743.24088-1-digetx@gmail.com> <20190624070413.GA23846@infradead.org> From: Dmitry Osipenko Message-ID: Date: Mon, 24 Jun 2019 15:55:04 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.7.1 MIME-Version: 1.0 In-Reply-To: <20190624070413.GA23846@infradead.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 24.06.2019 10:04, Christoph Hellwig пишет: > Don't we have a device tree problem here if there is a domain covering > them? I though we should only pick up an IOMMU for a given device > if DT explicitly asked for that? > There is no specific domain that "covering them". The IOMMU domain is allocated dynamically during of the Tegra DRM's driver initialization (see tegra_drm_load) and then all of DRM devices are attached to that domain once all of the DRM sub-drivers are probed successfully. On Tegra SoCs it's up to software (driver) to decide how to separate hardware devices from each other, in a case of DRM we're putting all the relevant graphics devices into a single domain. Is it even possible to express IOMMU domain (not group!) assignments in a device-tree?