Re: [PATCH v1 3/5] soc: qcom: memory_dump: Add memory dump driver

[Zhenhua Huang]

On 2023/10/23 17:31, Krzysztof Kozlowski wrote:
> On 23/10/2023 11:20, Zhenhua Huang wrote:
> > Qualcomm memory dump driver initializes system memory dump table.
> > Firmware dumps system cache, internal memory, peripheral registers
> > to DDR as per this table after system crashes and warm resets. The
> > driver reserves memory, populates ids and sizes for firmware dumping
> > according to the configuration.
> >
> > Signed-off-by: Zhenhua Huang <quic_zhenhuah@xxxxxxxxxxx>
> > ---
>
> ...
>
> > +
> > +/* populate allocated region */
> > +static int __init mem_dump_populate_mem(struct device *dev,
> > +					struct page *start_page,
> > +					size_t total_size)
> > +{
> > +	struct qcom_memory_dump *memdump = dev_get_drvdata(dev);
> > +	struct qcom_dump_entry dump_entry;
> > +	struct qcom_dump_data *dump_data;
> > +	struct xbc_node *linked_list;
> > +	phys_addr_t phys_end_addr;
> > +	phys_addr_t phys_addr;
> > +	const char *size_p;
> > +	void *dump_vaddr;
> > +	const char *id_p;
> > +	int ret = 0;
> > +	int size;
> > +	int id;
> > +
> > +	phys_addr = page_to_phys(start_page);
> > +	phys_end_addr = phys_addr + total_size;
> > +	dump_vaddr = page_to_virt(start_page);
> > +
> > +	ret = mem_dump_register_data_table(dev, dump_vaddr, phys_addr);
> > +	if (ret) {
> > +		dev_err_probe(dev, ret, "Mem Dump table set up is failed\n");
> > +		return ret;
>
> That's not the syntax. Syntax is return dev_err_probe

Got it, Thanks.

> > +	}
> > +
> > +	ret = qcom_init_memdump_imem_area(dev, total_size);
> > +	if (ret)
> > +		return ret;
> > +
> > +	/* Apply two tables: QCOM_DUMP_TYPE_TABLE and QCOM_DUMP_TYPE_DATA */
> > +	mem_dump_apply_offset(&dump_vaddr, &phys_addr,
> > +			      sizeof(struct qcom_dump_table) * 2);
> > +
> > +	/* Both "id" and "size" must be present */
> > +	xbc_node_for_each_subkey(memdump->mem_dump_node, linked_list) {
> > +		const char *name = xbc_node_get_data(linked_list);
> > +
> > +		if (!name)
> > +			continue;
> > +
> > +		id_p = xbc_node_find_value(linked_list, "id", NULL);
> > +		size_p = xbc_node_find_value(linked_list, "size", NULL);
> > +
> > +		if (id_p && size_p) {
> > +			ret = kstrtoint(id_p, 0, &id);
> > +			if (ret)
> > +				continue;
> > +
> > +			ret = kstrtoint(size_p, 0, &size);
> > +
> > +			if (ret)
> > +				continue;
> > +
> > +		/*
> > +		 * Physical layout: starting from two qcom_dump_data.
> > +		 * Following are respective dump meta data and reserved regions.
> > +		 * Qcom_dump_data is populated by the driver, fw parse it
> > +		 * and dump respective info into dump mem.
> > +		 * Illustrate the layout:
> > +		 *
> > +		 *   +------------------------+------------------------+
> > +		 *   | qcom_dump_table(TABLE) | qcom_dump_table(DATA)  |
> > +		 *   +------------------------+------------------------+
> > +		 *   +-------------+----------+-------------+----------+
> > +		 *   |qcom_dump_data| dump mem|qcom_dump_data| dump mem |
> > +		 *   +-------------+----------+-------------+----------+
> > +		 *   +-------------+----------+-------------+----------+
> > +		 *   |qcom_dump_data| dump mem|qcom_dump_data| dump mem |
> > +		 *   +-------------+----------+-------------+----------+
> > +		 *   ...
> > +		 */
>
> You have wrong indentation here.

Thanks for catching.

> > +			dump_data = dump_vaddr;
> > +			dump_data->addr = phys_addr + QCOM_DUMP_DATA_SIZE;
> > +			dump_data->len = size;
> > +			dump_entry.id = id;
> > +			strscpy(dump_data->name, name,
> > +				sizeof(dump_data->name));
> > +			dump_entry.addr = phys_addr;
> > +			ret = mem_dump_data_register(dev, QCOM_DUMP_TABLE_LINUX,
> > +						     &dump_entry);
> > +			if (ret) {
> > +				dev_err_probe(dev, ret, "Dump data setup failed, id = %d\n",
> > +					      id);
>
> Syntax is return dev_err_probe
>
> > +				return ret;
> > +			}
> > +
> > +			mem_dump_apply_offset(&dump_vaddr, &phys_addr,
> > +					      size + QCOM_DUMP_DATA_SIZE);
> > +			if (phys_addr > phys_end_addr) {
> > +				dev_err_probe(dev, -ENOMEM, "Exceeding allocated region\n");
>
> ENOMEM? Does not look right then.

ENOMEM means the memory allocated not enough? any suggestion? Thanks.

> > +				return -ENOMEM;
> > +			}
> > +		} else {
> > +			continue;
> > +		}
> > +	}
> > +
> > +	return ret;
> > +}
> > +
> > +static int __init mem_dump_probe(struct platform_device *pdev)
> > +{
> > +	struct qcom_memory_dump *memdump;
> > +	struct device *dev = &pdev->dev;
> > +	struct page *page;
> > +	size_t total_size;
> > +	int ret = 0;
> > +
> > +	memdump = devm_kzalloc(dev, sizeof(struct qcom_memory_dump),
> > +			       GFP_KERNEL);
> > +	if (!memdump)
> > +		return -ENOMEM;
> > +
> > +	dev_set_drvdata(dev, memdump);
> > +
> > +	/* check and initiate CMA region */
> > +	ret = mem_dump_reserve_mem(dev);
> > +	if (ret)
> > +		return ret;
> > +
> > +	/* allocate and populate */
> > +	page = mem_dump_alloc_mem(dev, &total_size);
> > +	if (IS_ERR(page)) {
> > +		ret = PTR_ERR(page);
> > +		dev_err_probe(dev, ret, "mem dump alloc failed\n");
>
> No, the syntax is:
> ret = dev_err_probe
>
> But why do you print messgaes for memory allocations?

Do you think it's useless because mm codes should print error as well if 
failure ?

> > +		goto release;
> > +	}
> > +
> > +	ret = mem_dump_populate_mem(dev, page, total_size);
> > +	if (!ret)
> > +		dev_info(dev, "Mem dump region populated successfully\n");
>
> Drop simple probe success messages. Not needed.

OK

> > +	else
> > +		goto free;
> > +
> > +	return 0;
> > +
> > +free:
> > +	cma_release(dev_get_cma_area(dev), page, (total_size / PAGE_SIZE));
> > +
> > +release:
> > +	of_reserved_mem_device_release(dev);
>
> Where is cleanup on unbind?

Will add, Thanks for pointing out.

> > +	return ret;
> > +}
> > +
> > +static const struct of_device_id mem_dump_match_table[] = {
> > +	{.compatible = "qcom,mem-dump",},
> > +	{}
> > +};
> > +
> Best regards,
> Krzysztof

Thanks,
Zhenhua