linux-kernel - Re: [PATCH v4 2/2] arm64: dts: qcom: sdm845: Extend ranges and describe DMA space

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]

Message-ID: <154774935672.169631.8429033154347254149@swboyd.mtv.corp.google.com>
Date:   Thu, 17 Jan 2019 10:22:36 -0800
From:   Stephen Boyd <swboyd@...omium.org>
To:     Andy Gross <andy.gross@...aro.org>,
        Bjorn Andersson <bjorn.andersson@...aro.org>,
        David Brown <david.brown@...aro.org>,
        Doug Anderson <dianders@...omium.org>,
        Mark Rutland <mark.rutland@....com>,
        Rob Herring <robh+dt@...nel.org>
Cc:     linux-arm-msm@...r.kernel.org, devicetree@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH v4 2/2] arm64: dts: qcom: sdm845: Extend ranges and describe DMA space

Quoting Bjorn Andersson (2019-01-16 20:29:40)
> For devices attached to an IOMMU, translation between IOVA and physical
> addresses is no longer 1:1 and dma-ranges should be specified to
> describe the available IOVA address space.
> 
> On SDM845 the busses are implemented with 36 address bits, so dma-ranges
> must be defined to reduce the size of the IOVA address space from the 48
> bits supported by the SMMU. Without this DMA allocations may end up with
> IOVAs outside the valid range, that gets truncated by the bus between
> the device and its translation unit.
> 
> Also extend ranges to describe the available address space.
> 
> Signed-off-by: Bjorn Andersson <bjorn.andersson@...aro.org>
> ---

Reviewed-by: Stephen Boyd <swboyd@...omium.org>