Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:8 as permitted sender) client-ip=2620:137:e000::3:8;
Message-ID: <5e5359d0-6f32-7312-b344-2d84be63d03d@quicinc.com>
Date:   Wed, 13 Sep 2023 20:48:30 +0530
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101
 Thunderbird/102.13.0
Subject: Re: [PATCH v5 06/17] soc: qcom: Add Qualcomm APSS minidump kernel
 driver
Content-Language: en-US
To:     Jeff Johnson <quic_jjohnson@quicinc.com>,
        Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>,
        <corbet@lwn.net>, <agross@kernel.org>, <andersson@kernel.org>,
        <konrad.dybcio@linaro.org>, <robh+dt@kernel.org>,
        <krzysztof.kozlowski+dt@linaro.org>, <conor+dt@kernel.org>,
        <keescook@chromium.org>, <tony.luck@intel.com>,
        <gpiccoli@igalia.com>, <mathieu.poirier@linaro.org>,
        <catalin.marinas@arm.com>, <will@kernel.org>,
        <linus.walleij@linaro.org>, <andy.shevchenko@gmail.com>,
        <vigneshr@ti.com>, <nm@ti.com>, <matthias.bgg@gmail.com>,
        <kgene@kernel.org>, <alim.akhtar@samsung.com>,
        <bmasney@redhat.com>, <quic_tsoni@quicinc.com>
CC:     <linux-doc@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <linux-arm-msm@vger.kernel.org>, <linux-hardening@vger.kernel.org>,
        <linux-remoteproc@vger.kernel.org>,
        <linux-arm-kernel@lists.infradead.org>,
        <linux-gpio@vger.kernel.org>, <linux-mediatek@lists.infradead.org>,
        <linux-samsung-soc@vger.kernel.org>, <kernel@quicinc.com>
References: <1694290578-17733-1-git-send-email-quic_mojha@quicinc.com>
 <1694290578-17733-7-git-send-email-quic_mojha@quicinc.com>
 <e35a8b4f-ba1a-514e-9c59-a74442f0cb1f@linaro.org>
 <36d9bd32-7ea4-4d84-b1e9-3cfcc3bec85c@quicinc.com>
From:   Mukesh Ojha <quic_mojha@quicinc.com>
In-Reply-To: <36d9bd32-7ea4-4d84-b1e9-3cfcc3bec85c@quicinc.com>
Content-Type: text/plain; charset="UTF-8"; format=flowed
Content-Transfer-Encoding: 8bit
Precedence: bulk


On 9/12/2023 12:39 AM, Jeff Johnson wrote:
> On 9/11/2023 4:07 AM, Krzysztof Kozlowski wrote:
>> On 09/09/2023 22:16, Mukesh Ojha wrote:
>>> +/**
>>> + * qcom_minidump_region_register() - Register region in APSS 
>>> Minidump table.
>>> + * @region: minidump region.
>>> + *
>>> + * Return: On success, it returns 0 and negative error value on 
>>> failure.
>>> + */
>>> +int qcom_minidump_region_register(const struct qcom_minidump_region 
>>> *region)
>>> +{
>>> +    struct minidump *md;
>>> +    int ret;
>>> +
>>> +    md = qcom_smem_minidump_ready();
>>> +    if (!md)
>>> +        return -EPROBE_DEFER;
>>> +
>>> +    if (!qcom_minidump_valid_region(region))
>>> +        return -EINVAL;
>>> +
>>> +    mutex_lock(&md->md_lock);
>>> +    ret = qcom_md_region_register(md, region);
>>> +    if (ret)
>>> +        goto unlock;
>>> +
>>> +    qcom_md_update_elfheader(md, region);
>>> +unlock:
>>> +    mutex_unlock(&md->md_lock);
>>> +    return ret;
>>> +}
>>> +EXPORT_SYMBOL_GPL(qcom_minidump_region_register);
>>
>> NAK, there is no user for this.
>>
>> Drop all exports from minidump drivers. Your upstream driver *must not*
>> expose stuff to your vendor drivers.
> 
> Do we not expect that upstream drivers would want to register?

As of current version of patch, there is no user. Let's avoid till
any upstream QCOM driver uses it .


> Mind you, in the downstream code the following was a bad limitation:
> #define MAX_NUM_OF_SS           10

I don't think, there is any problem with above macro, instead there is
restriction on total number of APSS region can be registered.

#define MAX_NUM_ENTRIES	  201

-Mukesh
> 
>