From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joerg Roedel Subject: Re: [RFC PATCH v1 0/6] Resolve unwanted DMA backing with IOMMU Date: Fri, 27 Jul 2018 20:31:34 +0200 Message-ID: <20180727183134.GD6738@8bytes.org> References: <20180726231624.21084-1-digetx@gmail.com> <20180727082512.lpvmeuvxnw3mpeym@8bytes.org> <20180727090328.GH28088@arm.com> <4164951.xGHfcFJ9uZ@dimapc> <20180727142000.76zgficpta473snl@8bytes.org> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" To: Rob Herring Cc: devicetree@vger.kernel.org, Mikko Perttunen , "Rafael J. Wysocki" , kwizart@gmail.com, Greg Kroah-Hartman , Will Deacon , Russell King , dri-devel , Jon Hunter , linux-tegra@vger.kernel.org, Linux IOMMU , Thierry Reding , bskeggs@redhat.com, Catalin Marinas , nouveau@lists.freedesktop.org, Dmitry Osipenko , Frank Rowand , "linux-kernel@vger.kernel.org" List-Id: iommu@lists.linux-foundation.org T24gRnJpLCBKdWwgMjcsIDIwMTggYXQgMTE6MTM6MzFBTSAtMDYwMCwgUm9iIEhlcnJpbmcgd3Jv dGU6Cj4gSSBkb24ndCBmb2xsb3cgd2h5IHdlIG5lZWQgYSBwcm9wZXJ0eSByYXRoZXIgdGhhbiBi ZWluZyBpbXBsaWVkIGJ5IHRoZQo+IGRldmljZSdzICh0aGUgR1BVKSBjb21wYXRpYmxlIHN0cmlu Zy4KClRoZXJlIG1pZ2h0IGJlIGRldmljZXMgd2hlcmUgZWl0aGVyIHNldHVwIHdvcmtzLCB3aXRo IG9yIHdpdGhvdXQgSU9NTVUKdHJhbnNsYXRpb24sIGFuZCB0aGUgZmlybXdhcmUgY2FuIHNldCB0 aGUgcHJvcGVydHkgZGVwZW5kaW5nIG9uIHdoZXRoZXIKdGhlIHVzZXIgd2FudHMgbW9yZSBwZXJm b3JtYW5jZSBvciBtb3JlIHNlY3VyaXR5LgoKSWYgd2UgaGF2ZSBhIHdoaXRlbGlzdCBpbiB0aGUg a2VybmVsIHRoaXMgZ2V0cyBtb3JlIGNvbXBsaWNhdGVkLCB3ZQpwcm9iYWJseSBuZWVkIGFkZGl0 aW9uYWwga2VybmVsLXBhcmFtZXRlcnMgdG8gb3ZlcndyaXRlIHRob3NlIHdoaXRlbGlzdAplbnRy aWVzLiBIYXZpbmcgYSBwcm9wZXJ0eSBpbiB0aGUgZGV2aWNlLXRyZWUgc2VlbXMgdG8gYmUgYSBi ZXR0ZXIgd2F5CmhlcmUsIGltaG8uCgoKCUpvZXJnCgpfX19fX19fX19fX19fX19fX19fX19fX19f X19fX19fX19fX19fX19fX19fX19fXwpkcmktZGV2ZWwgbWFpbGluZyBsaXN0CmRyaS1kZXZlbEBs aXN0cy5mcmVlZGVza3RvcC5vcmcKaHR0cHM6Ly9saXN0cy5mcmVlZGVza3RvcC5vcmcvbWFpbG1h bi9saXN0aW5mby9kcmktZGV2ZWwK 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=-2.1 required=3.0 tests=DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,T_DKIM_INVALID, USER_AGENT_MUTT 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 1A3E5C6778F for ; Fri, 27 Jul 2018 18:31:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C6C0420673 for ; Fri, 27 Jul 2018 18:31:38 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=8bytes.org header.i=@8bytes.org header.b="HPqtv6Uv" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C6C0420673 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=8bytes.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389088AbeG0Tym (ORCPT ); Fri, 27 Jul 2018 15:54:42 -0400 Received: from 8bytes.org ([81.169.241.247]:41568 "EHLO theia.8bytes.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730636AbeG0Tym (ORCPT ); Fri, 27 Jul 2018 15:54:42 -0400 Received: by theia.8bytes.org (Postfix, from userid 1000) id EA98D1F0; Fri, 27 Jul 2018 20:31:34 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=8bytes.org; s=mail-1; t=1532716294; bh=KpqDg2KCcbkFS/0m+A6X1Q2Zw8YtqGMgsvCds18pF+c=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=HPqtv6UvTLD0pwhJNtzupdtjAMcn1jPjzTp8Zw3SUYEKLeqW4g/0Wthyie2k+q/qg QShwcXGHrH+iIwklfF6WUPJUshGMkV5oiHQSz89fFiKSNJhGGVLuiyKEs9ZVBzV7mC c6uOzqZ1pOgacX1BWdQLX6UyzLm5MrL0aru6yib3SP9brJZ1z4wVY211DdfINKUQdU XfsXB8axI/887MVXoDnDC+UNCh8X5KSSS3ssdQw0J+1njPi/o9UiVwkG4G5zSskNOo Td5Me0+nyozHeohK0083d1E5lKicwRc/cc06UYe3RjgZtcdR2TglSGOokr0dMxKta1 KtUCCsdhNjEBg== Date: Fri, 27 Jul 2018 20:31:34 +0200 From: Joerg Roedel To: Rob Herring Cc: Dmitry Osipenko , Will Deacon , Greg Kroah-Hartman , "Rafael J. Wysocki" , Thierry Reding , Jon Hunter , Mikko Perttunen , Frank Rowand , bskeggs@redhat.com, Russell King , Catalin Marinas , kwizart@gmail.com, devicetree@vger.kernel.org, nouveau@lists.freedesktop.org, Linux IOMMU , dri-devel , linux-tegra@vger.kernel.org, "linux-kernel@vger.kernel.org" Subject: Re: [RFC PATCH v1 0/6] Resolve unwanted DMA backing with IOMMU Message-ID: <20180727183134.GD6738@8bytes.org> References: <20180726231624.21084-1-digetx@gmail.com> <20180727082512.lpvmeuvxnw3mpeym@8bytes.org> <20180727090328.GH28088@arm.com> <4164951.xGHfcFJ9uZ@dimapc> <20180727142000.76zgficpta473snl@8bytes.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jul 27, 2018 at 11:13:31AM -0600, Rob Herring wrote: > I don't follow why we need a property rather than being implied by the > device's (the GPU) compatible string. There might be devices where either setup works, with or without IOMMU translation, and the firmware can set the property depending on whether the user wants more performance or more security. If we have a whitelist in the kernel this gets more complicated, we probably need additional kernel-parameters to overwrite those whitelist entries. Having a property in the device-tree seems to be a better way here, imho. Joerg