Thanks for your time in reviewing this.
On 9/11/2023 4:31 PM, Krzysztof Kozlowski wrote:
> On 09/09/2023 22:16, Mukesh Ojha wrote:
>> Minidump is a best effort mechanism to collect useful and predefined
>> data for first level of debugging on end user devices running on
>> Qualcomm SoCs. It is built on the premise that System on Chip (SoC)
>> or subsystem part of SoC crashes, due to a range of hardware and
>> software bugs. Hence, the ability to collect accurate data is only
>> a best-effort. The data collected could be invalid or corrupted,
>> data collection itself could fail, and so on.
>
> ...
>
>> +static int qcom_apss_md_table_init(struct minidump *md,
>> + struct minidump_subsystem *mdss_toc)
>> +{
>> + struct minidump_ss_data *mdss_data;
>> +
>> + mdss_data = devm_kzalloc(md->dev, sizeof(*mdss_data), GFP_KERNEL);
>> + if (!mdss_data)
>> + return -ENOMEM;
>> +
>> + mdss_data->md_ss_toc = mdss_toc;
>> + mdss_data->md_regions = devm_kcalloc(md->dev, MAX_NUM_ENTRIES,
>> + sizeof(struct minidump_region),
>> + GFP_KERNEL);
>> + if (!mdss_data->md_regions)
>> + return -ENOMEM;
>> +
>> + mdss_toc = mdss_data->md_ss_toc;
>> + mdss_toc->regions_baseptr = cpu_to_le64(virt_to_phys(mdss_data->md_regions));
>> + mdss_toc->enabled = cpu_to_le32(MINIDUMP_SS_ENABLED);
>> + mdss_toc->status = cpu_to_le32(1);
>> + mdss_toc->region_count = cpu_to_le32(0);
>> +
>> + /* Tell bootloader not to encrypt the regions of this subsystem */
>> + mdss_toc->encryption_status = cpu_to_le32(MINIDUMP_SS_ENCR_DONE);
>> + mdss_toc->encryption_required = cpu_to_le32(MINIDUMP_SS_ENCR_NOTREQ);
>> +
>> + md->apss_data = mdss_data;
>> +
>> + return 0;
>> +}
>> +
>> +static int qcom_apss_minidump_probe(struct platform_device *pdev)
>> +{
>> + struct minidump_global_toc *mdgtoc;
>> + struct minidump *md;
>> + size_t size;
>> + int ret;
>> +
>> + md = devm_kzalloc(&pdev->dev, sizeof(struct minidump), GFP_KERNEL);
>
> sizeof(*)
>
> Didn't you get such comments already?
Ok, will fix this, no i have not got such comments as of yet.
Any reason of using this way?
>
>
>> + if (!md)
>> + return -ENOMEM;
>> +
>> + md->dev = &pdev->dev;
>> + mdgtoc = qcom_smem_get(QCOM_SMEM_HOST_ANY, SBL_MINIDUMP_SMEM_ID, &size);
>> + if (IS_ERR(mdgtoc)) {
>> + ret = PTR_ERR(mdgtoc);
>> + dev_err(md->dev, "Couldn't find minidump smem item: %d\n", ret);
>> + return ret;
>
> The syntax is:
> return dev_err_probe
ACK.
>
>> + }
>> +
>> + if (size < sizeof(*mdgtoc) || !mdgtoc->status) {
>> + dev_err(md->dev, "minidump table is not initialized: %d\n", ret);
>
> ret is uninitialized here. Please use automated tools for checking your
> code:
> coccinelle, smatch and sparse
Thanks.
>
>> + return -EINVAL;
>> + }
>> +
>> + mutex_init(&md->md_lock);
>> + ret = qcom_apss_md_table_init(md, &mdgtoc->subsystems[MINIDUMP_APSS_DESC]);
>> + if (ret) {
>> + dev_err(md->dev, "apss minidump initialization failed: %d\n", ret);
>> + return ret;
>> + }
>> +
>> + /* First entry would be ELF header */
>> + ret = qcom_md_add_elfheader(md);
>> + if (ret) {
>> + dev_err(md->dev, "Failed to add elf header: %d\n", ret);
>> + memset(md->apss_data->md_ss_toc, 0, sizeof(struct minidump_subsystem));
>
> Why do you need it?
Earlier, i got comment about clearing the SS TOC(subsystem table of
content) which is shared with other SS and it will have stale values.
>
>> + return ret;
>> + }
>> +
>> + platform_set_drvdata(pdev, md);
>> +
>> + return ret;
>> +}
>> +
>> +static int qcom_apss_minidump_remove(struct platform_device *pdev)
>> +{
>> + struct minidump *md = platform_get_drvdata(pdev);
>> + struct minidump_ss_data *mdss_data;
>> +
>> + mdss_data = md->apss_data;
>> + memset(mdss_data->md_ss_toc, cpu_to_le32(0), sizeof(struct minidump_subsystem));
>
> Why do you need it?
Same as above.
>
>> + md = NULL;
>
> That's useless assignment.
Ok.
>
>> +
>> + return 0;
>> +}
>> +
>> +static struct platform_driver qcom_minidump_driver = {
>> + .probe = qcom_apss_minidump_probe,
>> + .remove = qcom_apss_minidump_remove,
>> + .driver = {
>> + .name = "qcom-minidump-smem",
>> + },
>> +};
>> +
>> +module_platform_driver(qcom_minidump_driver);
>> +
>> +MODULE_DESCRIPTION("Qualcomm APSS minidump driver");
>> +MODULE_LICENSE("GPL");
>> +MODULE_ALIAS("platform:qcom-minidump-smem");
>
> Add a proper ID table instead of re-inventing it with module aliases.
Ok.
-Mukesh
>
> Best regards,
> Krzysztof
>
On 12/09/2023 11:26, Mukesh Ojha wrote:
>>
>>> + return -EINVAL;
>>> + }
>>> +
>>> + mutex_init(&md->md_lock);
>>> + ret = qcom_apss_md_table_init(md, &mdgtoc->subsystems[MINIDUMP_APSS_DESC]);
>>> + if (ret) {
>>> + dev_err(md->dev, "apss minidump initialization failed: %d\n", ret);
>>> + return ret;
>>> + }
>>> +
>>> + /* First entry would be ELF header */
>>> + ret = qcom_md_add_elfheader(md);
>>> + if (ret) {
>>> + dev_err(md->dev, "Failed to add elf header: %d\n", ret);
>>> + memset(md->apss_data->md_ss_toc, 0, sizeof(struct minidump_subsystem));
>>
>> Why do you need it?
>
> Earlier, i got comment about clearing the SS TOC(subsystem table of
> content) which is shared with other SS and it will have stale values.
OK, but then the entire code is poorly readable. First, any cleanup of
qcom_apss_md_table_init() should be named similarly, e.g.
qcom_apss_md_table_clean() or qcom_apss_md_table_exit() or whatever
seems feasible.
Second, shouldn't writing to shared memory be the last step? Step which
cannot fail and there is no cleanup afterwards (like
platform_set_drvdata)? I don't enjoy looking at this interface...
Best regards,
Krzysztof
On 9/12/2023 3:24 PM, Krzysztof Kozlowski wrote:
> On 12/09/2023 11:26, Mukesh Ojha wrote:
>>>
>>>> + return -EINVAL;
>>>> + }
>>>> +
>>>> + mutex_init(&md->md_lock);
>>>> + ret = qcom_apss_md_table_init(md, &mdgtoc->subsystems[MINIDUMP_APSS_DESC]);
>>>> + if (ret) {
>>>> + dev_err(md->dev, "apss minidump initialization failed: %d\n", ret);
>>>> + return ret;
>>>> + }
>>>> +
>>>> + /* First entry would be ELF header */
>>>> + ret = qcom_md_add_elfheader(md);
>>>> + if (ret) {
>>>> + dev_err(md->dev, "Failed to add elf header: %d\n", ret);
>>>> + memset(md->apss_data->md_ss_toc, 0, sizeof(struct minidump_subsystem));
>>>
>>> Why do you need it?
>>
>> Earlier, i got comment about clearing the SS TOC(subsystem table of
>> content) which is shared with other SS and it will have stale values.
>
> OK, but then the entire code is poorly readable. First, any cleanup of
> qcom_apss_md_table_init() should be named similarly, e.g.
> qcom_apss_md_table_clean() or qcom_apss_md_table_exit() or whatever
> seems feasible.
ACK on this.
>
> Second, shouldn't writing to shared memory be the last step? Step which
> cannot fail and there is no cleanup afterwards (like
> platform_set_drvdata)? I don't enjoy looking at this interface...
It can be done, if i shift adding elf header as first thing to first
caller of qcom_minidump_region_register() but then i would have to
remove qcom_ramoops_minidump() from this probe in 11/17 patch.
-Mukesh
>
>
>
> Best regards,
> Krzysztof
>