linux-kernel - Re: [PATCH v1 1/3] gpu: host1x: Remove implicit IOMMU backing on client's registration

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Mon, 24 Jun 2019 15:55:04 +0300
From:   Dmitry Osipenko <digetx@...il.com>
To:     Christoph Hellwig <hch@...radead.org>
Cc:     Thierry Reding <thierry.reding@...il.com>,
        dri-devel@...ts.freedesktop.org, linux-tegra@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH v1 1/3] gpu: host1x: Remove implicit IOMMU backing on
 client's registration

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?