Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <ef50ac6c-a635-7f83-c484-a4f91b5e5d12@quicinc.com>
Date:   Fri, 5 May 2023 18:27:57 +0530
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101
 Thunderbird/102.10.0
Subject: Re: [PATCH v2 06/18] media: venus: firmware: Leave a clue for
 homegrown porters
Content-Language: en-US
To:     Konrad Dybcio <konrad.dybcio@linaro.org>,
        Stanimir Varbanov <stanimir.k.varbanov@gmail.com>,
        Andy Gross <agross@kernel.org>,
        "Bjorn Andersson" <andersson@kernel.org>,
        Mauro Carvalho Chehab <mchehab@kernel.org>,
        Dikshita Agarwal <dikshita@qti.qualcomm.com>,
        Bryan O'Donoghue <bryan.odonoghue@linaro.org>,
        Mansur Alisha Shaik <mansur@codeaurora.org>,
        Jonathan Marek <jonathan@marek.ca>,
        Hans Verkuil <hans.verkuil@cisco.com>,
        Dikshita Agarwal <quic_dikshita@quicinc.com>
CC:     Mauro Carvalho Chehab <mchehab+huawei@kernel.org>,
        Stanimir Varbanov <stanimir.varbanov@linaro.org>,
        <linux-media@vger.kernel.org>, <linux-arm-msm@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>,
        "Marijn Suijten" <marijn.suijten@somainline.org>
References: <20230228-topic-venus-v2-0-d95d14949c79@linaro.org>
 <20230228-topic-venus-v2-6-d95d14949c79@linaro.org>
From:   Vikash Garodia <quic_vgarodia@quicinc.com>
In-Reply-To: <20230228-topic-venus-v2-6-d95d14949c79@linaro.org>
Content-Type: text/plain; charset="UTF-8"; format=flowed
Content-Transfer-Encoding: 7bit
Precedence: bulk


On 5/4/2023 1:31 PM, Konrad Dybcio wrote:
> Leave a clue about where the seemingly magic values come from, as it
> is not obvious and requires some digging downstream..
>
> Reviewed-by: Dikshita Agarwal <quic_dikshita@quicinc.com>
> Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Reviewed-by: Vikash Garodia <quic_vgarodia@quicinc.com>
> ---
>   drivers/media/platform/qcom/venus/firmware.c | 7 +++++++
>   1 file changed, 7 insertions(+)
>
> diff --git a/drivers/media/platform/qcom/venus/firmware.c b/drivers/media/platform/qcom/venus/firmware.c
> index cfb11c551167..a4cd919e1dbe 100644
> --- a/drivers/media/platform/qcom/venus/firmware.c
> +++ b/drivers/media/platform/qcom/venus/firmware.c
> @@ -241,6 +241,13 @@ int venus_boot(struct venus_core *core)
>   		return ret;
>   
>   	if (core->use_tz && res->cp_size) {
> +		/*
> +		 * Clues for porting using downstream data:
> +		 * cp_start = 0
> +		 * cp_size = venus_ns/virtual-addr-pool[0] (yes, addr not size)

The field is the start address of ns context bank. Since the cp_start is 
0, the start address for (next) non-secure context bank

is interpreted as size of the (previous) content protection region.

> +		 * cp_nonpixel_start = venus_sec_non_pixel/virtual-addr-pool[0]
> +		 * cp_nonpixel_size = venus_sec_non_pixel/virtual-addr-pool[1]
> +		 */
>   		ret = qcom_scm_mem_protect_video_var(res->cp_start,
>   						     res->cp_size,
>   						     res->cp_nonpixel_start,
>