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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no 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 7A4BFC76188 for ; Mon, 22 Jul 2019 15:48:16 +0000 (UTC) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org [140.211.169.12]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 5630020821 for ; Mon, 22 Jul 2019 15:48:16 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5630020821 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=8bytes.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from mail.linux-foundation.org (localhost [127.0.0.1]) by mail.linuxfoundation.org (Postfix) with ESMTP id 3EBCCC9A; Mon, 22 Jul 2019 15:48:16 +0000 (UTC) Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 1CD24BA4 for ; Mon, 22 Jul 2019 15:48:15 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from theia.8bytes.org (8bytes.org [81.169.241.247]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id A9A49224 for ; Mon, 22 Jul 2019 15:48:06 +0000 (UTC) Received: by theia.8bytes.org (Postfix, from userid 1000) id 8B0901F2; Mon, 22 Jul 2019 17:48:04 +0200 (CEST) Date: Mon, 22 Jul 2019 17:48:03 +0200 From: Joerg Roedel To: Rob Clark Subject: Re: [PATCH v2] iommu: add support for drivers that manage iommu explicitly Message-ID: <20190722154803.GG12009@8bytes.org> References: <20190702202631.32148-2-robdclark@gmail.com> <20190710182844.25032-1-robdclark@gmail.com> <20190722142833.GB12009@8bytes.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Cc: Rob Clark , aarch64-laptops@lists.linaro.org, Andy Shevchenko , Heikki Krogerus , Linux Kernel Mailing List , linux-arm-msm , Bartosz Golaszewski , "Rafael J. Wysocki" , Rasmus Villemoes , Robin Murphy , Sudeep Holla , "list@263.net:IOMMU DRIVERS , Joerg Roedel , " , Greg Kroah-Hartman , Joe Perches , Andrew Morton , Will Deacon , "moderated list:ARM/FREESCALE IMX / MXC ARM ARCHITECTURE" X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: iommu-bounces@lists.linux-foundation.org Errors-To: iommu-bounces@lists.linux-foundation.org On Mon, Jul 22, 2019 at 08:41:34AM -0700, Rob Clark wrote: > It is set by the driver: > > https://patchwork.freedesktop.org/patch/315291/ > > (This doesn't really belong in devicetree, since it isn't a > description of the hardware, so the driver is really the only place to > set this.. which is fine because it is about a detail of how the > driver works.) It is more a detail about how the firmware works. IIUC the problem is that the firmware initializes the context mappings for the GPU and the OS doesn't know anything about that and just overwrites them, causing the firmware GPU driver to fail badly. So I think it is the task of the firmware to tell the OS not to touch the devices mappings until the OS device driver takes over. On x86 there is something similar with the RMRR/unity-map tables from the firmware. Regards, Joerg _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu