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Message-ID: <00b8721e-da69-dcf8-8f64-9a9028f24d13@linaro.org>
Date:   Mon, 19 Jun 2023 12:01:06 +0200
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Subject: Re: [PATCH v2 1/4] dt-bindings: firmware: qcom,scm: Document that SCM
 can be dma-coherent
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To:     Douglas Anderson <dianders@chromium.org>, andersson@kernel.org
Cc:     amit.pundir@linaro.org, Will Deacon <will@kernel.org>,
        sumit.semwal@linaro.org, linux-arm-msm@vger.kernel.org,
        konrad.dybcio@somainline.org, linux-arm-kernel@lists.infradead.org,
        Stephan Gerhold <stephan@gerhold.net>,
        Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>,
        Nikita Travkin <nikita@trvn.ru>,
        Stephen Boyd <swboyd@chromium.org>,
        Sibi Sankar <quic_sibis@quicinc.com>,
        Andy Gross <agross@kernel.org>,
        Conor Dooley <conor+dt@kernel.org>,
        Das Srinagesh <quic_gurus@quicinc.com>,
        Konrad Dybcio <konrad.dybcio@linaro.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Rob Herring <robh+dt@kernel.org>,
        Robert Marko <robimarko@gmail.com>, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org
References: <20230616081440.v2.1.Ie79b5f0ed45739695c9970df121e11d724909157@changeid>
From:   Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
In-Reply-To: <20230616081440.v2.1.Ie79b5f0ed45739695c9970df121e11d724909157@changeid>
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On 16/06/2023 17:14, Douglas Anderson wrote:
> Trogdor devices use firmware backed by TF-A instead of Qualcomm's
> normal TZ. On TF-A we end up mapping memory as cacheable. Specifically,
> you can see in Trogdor's TF-A code [1] in qti_sip_mem_assign() that we
> call qti_mmap_add_dynamic_region() with MT_RO_DATA. This translates
> down to MT_MEMORY instead of MT_NON_CACHEABLE or MT_DEVICE.
> 
> Let's allow devices like trogdor to be described properly by allowing
> "dma-coherent" in the SCM node.
> 
> Signed-off-by: Douglas Anderson <dianders@chromium.org>
> ---


Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

Best regards,
Krzysztof