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=-2.5 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 EBE73C49ED7 for ; Tue, 10 Sep 2019 16:52:06 +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 BDDF92168B for ; Tue, 10 Sep 2019 16:52:06 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BDDF92168B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com 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 85B7BE38; Tue, 10 Sep 2019 16:52:06 +0000 (UTC) Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id E1C7FE25 for ; Tue, 10 Sep 2019 16:52:05 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp1.linuxfoundation.org (Postfix) with ESMTP id 6A8C581A for ; Tue, 10 Sep 2019 16:52:05 +0000 (UTC) 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 F13301000; Tue, 10 Sep 2019 09:52:04 -0700 (PDT) Received: from [10.1.197.57] (e110467-lin.cambridge.arm.com [10.1.197.57]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id B2D733F71F; Tue, 10 Sep 2019 09:52:00 -0700 (PDT) Subject: Re: [PATCH v2 1/2] iommu: add support for drivers that manage iommu explicitly To: Rob Clark , Joerg Roedel References: <20190906214409.26677-1-robdclark@gmail.com> <20190906214409.26677-2-robdclark@gmail.com> <20190910081415.GB3247@8bytes.org> From: Robin Murphy Message-ID: <4b5b59bb-39a4-0757-e2bb-0961cfc7e4c1@arm.com> Date: Tue, 10 Sep 2019 17:51:57 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: Content-Language: en-GB Cc: Rob Clark , Heikki Krogerus , Arnd Bergmann , Suzuki K Poulose , linux-arm-msm , "Rafael J. Wysocki" , Rasmus Villemoes , open list , dri-devel , Sudeep Holla , iommu@lists.linux-foundation.org, Greg Kroah-Hartman , Joe Perches , Andrew Morton , Will Deacon , Bartosz Golaszewski 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-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: iommu-bounces@lists.linux-foundation.org Errors-To: iommu-bounces@lists.linux-foundation.org On 10/09/2019 16:34, Rob Clark wrote: > On Tue, Sep 10, 2019 at 1:14 AM Joerg Roedel wrote: >> >> On Fri, Sep 06, 2019 at 02:44:01PM -0700, Rob Clark wrote: >>> @@ -674,7 +674,7 @@ int iommu_group_add_device(struct iommu_group *group, struct device *dev) >>> >>> mutex_lock(&group->mutex); >>> list_add_tail(&device->list, &group->devices); >>> - if (group->domain) >>> + if (group->domain && !(dev->driver && dev->driver->driver_manages_iommu)) >> >> Hmm, this code usually runs at enumeration time when no driver is >> attached to the device. Actually it would be pretty dangerous when this >> code runs while a driver is attached to the device. How does that change >> make things work for you? >> > > I was seeing this get called via the path driver_probe_device() -> > platform_dma_configure() -> of_dma_configure() -> of_iommu_configure() > -> iommu_probe_device() -> ... > > The only cases I was seeing where dev->driver is NULL where a few > places that drivers call of_dma_configure() on their own sub-devices. > But maybe there are some other paths that I did not notice? For the of_iommu flow, it very much depends on your DT layout and driver probe order as to whether you catch the "proper" call from iommu_bus_notifier()/iommu_bus_init() or the late "replay" from of_iommu_configure(). I wouldn't make any assumptions of consistency. Robin. _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu