Re: [PATCH v4 10/21] soc: qcom: Add qcom's pstore minidump driver support

Mukesh Ojha
2023-06-29T09:17:40Z

On 6/29/2023 4:27 AM, Rob Herring wrote:
> On Wed, Jun 28, 2023 at 6:37 AM Mukesh Ojha <quic_mojha@quicinc.com> wrote:
>>
>> This driver was inspired from the fact pstore ram region should be
>> fixed and boot firmware need to have awarness about this region,
>> so that it will be persistent across boot. But, there are many
>> QCOM SoC which does not support warm boot from hardware but they
>> have minidump support from the software, and for them, there is
>> no need of this pstore ram region to be fixed, but at the same
>> time have interest in the pstore frontends data. So, this driver
>> get the dynamic reserved region from the ram and register the
>> ramoops platform device.
>>
>> +---------+ +---------+ +--------+ +---------+
>> | console | | pmsg | | ftrace | | dmesg |
>> +---------+ +---------+ +--------+ +---------+
>> | | | |
>> | | | |
>> +------------------------------------------+
>> |
>> \ /
>> +----------------+
>> (1) |pstore frontends|
>> +----------------+
>> |
>> \ /
>> +------------------- +
>> (2) | pstore backend(ram)|
>> +--------------------+
>> |
>> \ /
>> +--------------------+
>> (3) |qcom_pstore_minidump|
>> +--------------------+
>> |
>> \ /
>> +---------------+
>> (4) | qcom_minidump |
>> +---------------+
>>
>> This driver will route all the pstore front data to the stored
>> in qcom pstore reserved region and the reason of showing an
>> arrow from (3) to (4) as qcom_pstore_minidump driver will register
>> all the available frontends region with qcom minidump driver
>> in upcoming patch.
>>
>> Signed-off-by: Mukesh Ojha <quic_mojha@quicinc.com>
>> ---
>> drivers/soc/qcom/Kconfig | 12 +++++
>> drivers/soc/qcom/Makefile | 1 +
>> drivers/soc/qcom/qcom_pstore_minidump.c | 85 +++++++++++++++++++++++++++++++++
>
> drivers/soc/ is the dumping ground for things with no other place. As
> this is a pstore driver, it belongs with pstore.

The inspiration of this driver was taken from
drivers/platform/chrome/chromeos_pstore.c, do you think that is misplaced ?

>
>> 3 files changed, 98 insertions(+)
>> create mode 100644 drivers/soc/qcom/qcom_pstore_minidump.c
>>
>> diff --git a/drivers/soc/qcom/Kconfig b/drivers/soc/qcom/Kconfig
>> index 1834213fd652..fbf08e30feda 100644
>> --- a/drivers/soc/qcom/Kconfig
>> +++ b/drivers/soc/qcom/Kconfig
>> @@ -306,4 +306,16 @@ config QCOM_MINIDUMP_SMEM
>>
>> This config should be enabled if the low level minidump is implemented
>> as part of SMEM.
>> +
>> +config QCOM_PSTORE_MINIDUMP
>> + tristate "Pstore support for QCOM Minidump"
>> + depends on ARCH_QCOM
>> + depends on PSTORE_RAM
>> + depends on QCOM_MINIDUMP
>> + help
>> + Enablement of this driver ensures that ramoops region can be anywhere
>> + reserved in ram instead of being fixed address which needs boot firmware
>> + awareness. So, this driver creates plaform device and registers available
>> + frontend region with the Qualcomm's minidump driver.
>> +
>> endmenu
>> diff --git a/drivers/soc/qcom/Makefile b/drivers/soc/qcom/Makefile
>> index 737d868757ac..1ab59c1b364d 100644
>> --- a/drivers/soc/qcom/Makefile
>> +++ b/drivers/soc/qcom/Makefile
>> @@ -36,3 +36,4 @@ qcom_ice-objs += ice.o
>> obj-$(CONFIG_QCOM_INLINE_CRYPTO_ENGINE) += qcom_ice.o
>> obj-$(CONFIG_QCOM_MINIDUMP) += qcom_minidump.o
>> obj-$(CONFIG_QCOM_MINIDUMP_SMEM) += qcom_minidump_smem.o
>> +obj-$(CONFIG_QCOM_PSTORE_MINIDUMP) += qcom_pstore_minidump.o
>> diff --git a/drivers/soc/qcom/qcom_pstore_minidump.c b/drivers/soc/qcom/qcom_pstore_minidump.c
>> new file mode 100644
>> index 000000000000..b07cd10340df
>> --- /dev/null
>> +++ b/drivers/soc/qcom/qcom_pstore_minidump.c
>> @@ -0,0 +1,85 @@
>> +// SPDX-License-Identifier: GPL-2.0-only
>> +
>> +/*
>> + * Copyright (c) 2023 Qualcomm Innovation Center, Inc. All rights reserved.
>> + */
>> +
>> +#include <linux/module.h>
>> +#include <linux/of_device.h>
>
> You probably don't need this include. Use the actual includes you need
> and don't rely on implicit includes (because I'm trying to remove
> those).

Ok, will try to check..

- Mukesh

>
>> +#include <linux/of_reserved_mem.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/pstore_ram.h>
>> +
>> +struct qcom_ramoops_dd {
>> + struct ramoops_platform_data qcom_ramoops_pdata;
>> + struct platform_device *ramoops_pdev;
>> +};
>> +
>> +static int qcom_ramoops_probe(struct platform_device *pdev)
>> +{
>> + struct device_node *of_node = pdev->dev.of_node;
>> + struct qcom_ramoops_dd *qcom_rdd;
>> + struct ramoops_platform_data *pdata;
>> + struct reserved_mem *rmem;
>> + struct device_node *node;
>> + long ret;
>> +
>> + node = of_parse_phandle(of_node, "memory-region", 0);
>> + if (!node)
>> + return -ENODEV;
>> +
>> + rmem = of_reserved_mem_lookup(node);
>> + of_node_put(node);
>> + if (!rmem) {
>> + dev_err(&pdev->dev, "failed to locate DT /reserved-memory resource\n");
>> + return -EINVAL;
>> + }
>> +
>> + qcom_rdd = devm_kzalloc(&pdev->dev, sizeof(*qcom_rdd), GFP_KERNEL);
>> + if (!qcom_rdd)
>> + return -ENOMEM;
>> +
>> + pdata = &qcom_rdd->qcom_ramoops_pdata;
>> + pdata->mem_size = rmem->size;
>> + pdata->mem_address = rmem->base;
>> + ramoops_parse_dt(pdev, pdata);
>> +
>> + qcom_rdd->ramoops_pdev = platform_device_register_data(NULL, "ramoops", -1,
>> + pdata, sizeof(*pdata));
>> + if (IS_ERR(qcom_rdd->ramoops_pdev)) {
>> + ret = PTR_ERR(qcom_rdd->ramoops_pdev);
>> + dev_err(&pdev->dev, "could not create platform device: %ld\n", ret);
>> + qcom_rdd->ramoops_pdev = NULL;
>> + }
>> + platform_set_drvdata(pdev, qcom_rdd);
>> +
>> + return ret;
>> +}
>> +
>> +static void qcom_ramoops_remove(struct platform_device *pdev)
>> +{
>> + struct qcom_ramoops_dd *qcom_rdd = platform_get_drvdata(pdev);
>> +
>> + platform_device_unregister(qcom_rdd->ramoops_pdev);
>> + qcom_rdd->ramoops_pdev = NULL;
>> +}
>> +
>> +static const struct of_device_id qcom_ramoops_of_match[] = {
>> + { .compatible = "qcom,ramoops"},
>> + {}
>> +};
>> +MODULE_DEVICE_TABLE(of, qcom_ramoops_of_match);
>> +
>> +static struct platform_driver qcom_ramoops_drv = {
>> + .driver = {
>> + .name = "qcom,ramoops",
>> + .of_match_table = qcom_ramoops_of_match,
>> + },
>> + .probe = qcom_ramoops_probe,
>> + .remove_new = qcom_ramoops_remove,
>> +};
>> +
>> +module_platform_driver(qcom_ramoops_drv);
>> +
>> +MODULE_DESCRIPTION("Qualcomm ramoops minidump driver");
>> +MODULE_LICENSE("GPL");
>> --
>> 2.7.4
>>