diff mbox series

[RFC,1/1] soc: qcom: Add driver to read secondary bootloader (XBL) log

Message ID 20230822121512.8631-2-quic_ninanaik@quicinc.com
State New
Headers show
Series Add driver to read secondary bootloader (XBL) log | expand

Commit Message

Ninad Naik Aug. 22, 2023, 12:15 p.m. UTC 
Qualcomm secondary bootloader (XBL) boot log holds information to
identify various firmware configuration currently set on the SoC.
The XBL log is stored in a predefined reserved memory region.

This drivers provides a way to print XBL logs on the console. To
do so, it provides a debugfs entry which captures the logs stored
in this reserved memory region. This entry can now be used to read
and print the XBL logs to console.

User can use the below command to print XBL log to console:
        cat /sys/kernel/debug/xbl_log

Signed-off-by: Ninad Naik <quic_ninanaik@quicinc.com>
---
 drivers/soc/qcom/Kconfig        |  13 +++
 drivers/soc/qcom/Makefile       |   1 +
 drivers/soc/qcom/dump_xbl_log.c | 139 ++++++++++++++++++++++++++++++++
 3 files changed, 153 insertions(+)
 create mode 100644 drivers/soc/qcom/dump_xbl_log.c

Comments

Bryan O'Donoghue Aug. 22, 2023, 12:43 p.m. UTC | #1 
On 22/08/2023 13:15, Ninad Naik wrote:
> Qualcomm secondary bootloader (XBL) boot log holds information to
> identify various firmware configuration currently set on the SoC.
> The XBL log is stored in a predefined reserved memory region.
> 
> This drivers provides a way to print XBL logs on the console. To
> do so, it provides a debugfs entry which captures the logs stored
> in this reserved memory region. This entry can now be used to read
> and print the XBL logs to console.
> 
> User can use the below command to print XBL log to console:
>          cat /sys/kernel/debug/xbl_log
> 
> Signed-off-by: Ninad Naik <quic_ninanaik@quicinc.com>
> ---
>   drivers/soc/qcom/Kconfig        |  13 +++
>   drivers/soc/qcom/Makefile       |   1 +
>   drivers/soc/qcom/dump_xbl_log.c | 139 ++++++++++++++++++++++++++++++++
>   3 files changed, 153 insertions(+)
>   create mode 100644 drivers/soc/qcom/dump_xbl_log.c
> 
> diff --git a/drivers/soc/qcom/Kconfig b/drivers/soc/qcom/Kconfig
> index 715348869d04..4489d37e924d 100644
> --- a/drivers/soc/qcom/Kconfig
> +++ b/drivers/soc/qcom/Kconfig
> @@ -291,4 +291,17 @@ config QCOM_INLINE_CRYPTO_ENGINE
>   	tristate
>   	select QCOM_SCM
>   
> +config QCOM_DUMP_XBL_LOG
> +	tristate "Qualcomm driver to print XBL logs on console from debugfs"
> +	help
> +	  This driver is used to capture secondary bootloader (xbl) log
> +	  from a reserved memory region and provide a debugfs entry to read
> +	  logs captured from this memory region and print them on console.
> +	  User can use below command to print the xbl log on console:
> +
> +                cat /sys/kernel/debug/xbl_log
> +
> +	  These logs help to identify firmware configuration information on
> +	  the SoC. The name of the built module will be dump_xbl_log
> +
>   endmenu
> diff --git a/drivers/soc/qcom/Makefile b/drivers/soc/qcom/Makefile
> index bbca2e1e55bb..aac088a1a0b6 100644
> --- a/drivers/soc/qcom/Makefile
> +++ b/drivers/soc/qcom/Makefile
> @@ -32,3 +32,4 @@ obj-$(CONFIG_QCOM_KRYO_L2_ACCESSORS) +=	kryo-l2-accessors.o
>   obj-$(CONFIG_QCOM_ICC_BWMON)	+= icc-bwmon.o
>   qcom_ice-objs			+= ice.o
>   obj-$(CONFIG_QCOM_INLINE_CRYPTO_ENGINE)	+= qcom_ice.o
> +obj-$(CONFIG_QCOM_DUMP_XBL_LOG)	+= dump_xbl_log.o
> diff --git a/drivers/soc/qcom/dump_xbl_log.c b/drivers/soc/qcom/dump_xbl_log.c
> new file mode 100644
> index 000000000000..ea335a5e660b
> --- /dev/null
> +++ b/drivers/soc/qcom/dump_xbl_log.c
> @@ -0,0 +1,139 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (c) 2021, The Linux Foundation. All rights reserved.
> + */

2023

> +
> +#include <linux/init.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/device.h>
> +#include <linux/platform_device.h>
> +#include <linux/memblock.h>
> +#include <linux/of_address.h>
> +#include <linux/err.h>
> +#include <linux/debugfs.h>

It would be nice to alphetise this include list.

> +struct xbl_log_data {
> +	struct device *dev;
> +	size_t buf_size;
> +	void __iomem *xbl_buf;
> +	struct dentry *dbg_file;
> +	struct debugfs_blob_wrapper dbg_data;
> +};
> +
> +static int map_addr_range(struct device_node **parent, const char *name,
> +			  struct xbl_log_data *xbl_data)
> +{
> +	struct device_node *node;
> +	struct resource res;
> +	int ret;
> +
> +	node = of_find_node_by_name(*parent, name);
> +	if (!node)
> +		return -ENODEV;
> +
> +	ret = of_address_to_resource(node, 0, &res);
> +	if (ret) {
> +		dev_err(xbl_data->dev, "Failed to parse memory region\n");
> +		return ret;
> +	}
> +	of_node_put(node);
> +
> +	if (!resource_size(&res)) {
> +		dev_err(xbl_data->dev, "Failed to parse memory region size\n");
> +		return -ENODEV;
> +	}
> +
> +	xbl_data->buf_size = resource_size(&res) - 1;
> +	xbl_data->xbl_buf = devm_memremap(xbl_data->dev, res.start,
> +					  xbl_data->buf_size, MEMREMAP_WB);
> +	if (!xbl_data->xbl_buf) {
> +		dev_err(xbl_data->dev, "%s: memory remap failed\n", name);
> +		return -ENOMEM;
> +	}
> +
> +	return 0;
> +}
> +
> +static int xbl_log_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct xbl_log_data *xbl_data;
> +	struct device_node *parent;
> +	int ret;
> +
> +	xbl_data = devm_kzalloc(dev, sizeof(*xbl_data), GFP_KERNEL);
> +	if (!xbl_data)
> +		return -ENOMEM;
> +
> +	xbl_data->dev = &pdev->dev;
> +	platform_set_drvdata(pdev, xbl_data);
> +
> +	parent = of_find_node_by_path("/reserved-memory");
> +	if (!parent) {
> +		dev_err(xbl_data->dev, "reserved-memory node missing\n");
> +		return -ENODEV;
> +	}
> +
> +	ret = map_addr_range(&parent, "uefi-log", xbl_data);
> +	if (ret)
> +		goto put_node;
> +
> +	xbl_data->dbg_data.data = xbl_data->xbl_buf;
> +	xbl_data->dbg_data.size = xbl_data->buf_size;
> +	xbl_data->dbg_file = debugfs_create_blob("xbl_log", 0400, NULL,
> +						 &xbl_data->dbg_data);
> +	if (IS_ERR(xbl_data->dbg_file)) {
> +		dev_err(xbl_data->dev, "failed to create debugfs entry\n");
> +		ret = PTR_ERR(xbl_data->dbg_file);
> +	}
> +
> +put_node:
> +	of_node_put(parent);
> +	return ret;
> +}
> +
> +static int xbl_log_remove(struct platform_device *pdev)
> +{
> +	struct xbl_log_data *xbl_data = platform_get_drvdata(pdev);
> +
> +	debugfs_remove_recursive(xbl_data->dbg_file);
> +	return 0;
> +}
> +
> +static struct platform_driver xbl_log_driver = {
> +	.probe = xbl_log_probe,
> +	.remove = xbl_log_remove,
> +	.driver = {
> +		   .name = "xbl-log",
> +		   },
Is that indentation correct ?

> +};
> +
> +static struct platform_device xbl_log_device = {
> +	.name = "xbl-log",
> +};
> +
> +static int __init xbl_log_init(void)
> +{
> +	int ret = 0;
> +
> +	ret = platform_driver_register(&xbl_log_driver);
> +	if (!ret) {
> +		ret = platform_device_register(&xbl_log_device);
> +		if (ret)
> +			platform_driver_unregister(&xbl_log_driver);
> +	}
> +	return ret;
> +}
> +
> +static void __exit xbl_log_exit(void)
> +{
> +	platform_device_unregister(&xbl_log_device);
> +	platform_driver_unregister(&xbl_log_driver);
> +}
> +
> +module_init(xbl_log_init);
> +module_exit(xbl_log_exit);
> +
> +MODULE_DESCRIPTION("Qualcomm Technologies, Inc. (QTI) XBL log driver");
> +MODULE_LICENSE("GPL");

---
bod
Srinivas Kandagatla Aug. 22, 2023, 1:41 p.m. UTC | #2 
On 22/08/2023 13:15, Ninad Naik wrote:
> Qualcomm secondary bootloader (XBL) boot log holds information to
> identify various firmware configuration currently set on the SoC.
> The XBL log is stored in a predefined reserved memory region.
> 
> This drivers provides a way to print XBL logs on the console. To
> do so, it provides a debugfs entry which captures the logs stored
> in this reserved memory region. This entry can now be used to read
> and print the XBL logs to console.
> 
> User can use the below command to print XBL log to console:
>          cat /sys/kernel/debug/xbl_log
> 
> Signed-off-by: Ninad Naik <quic_ninanaik@quicinc.com>
> ---
>   drivers/soc/qcom/Kconfig        |  13 +++
>   drivers/soc/qcom/Makefile       |   1 +
>   drivers/soc/qcom/dump_xbl_log.c | 139 ++++++++++++++++++++++++++++++++
>   3 files changed, 153 insertions(+)
>   create mode 100644 drivers/soc/qcom/dump_xbl_log.c
> 
> diff --git a/drivers/soc/qcom/Kconfig b/drivers/soc/qcom/Kconfig
> index 715348869d04..4489d37e924d 100644
> --- a/drivers/soc/qcom/Kconfig
> +++ b/drivers/soc/qcom/Kconfig
> @@ -291,4 +291,17 @@ config QCOM_INLINE_CRYPTO_ENGINE
>   	tristate
>   	select QCOM_SCM
>   
> +config QCOM_DUMP_XBL_LOG
> +	tristate "Qualcomm driver to print XBL logs on console from debugfs"
> +	help
> +	  This driver is used to capture secondary bootloader (xbl) log
> +	  from a reserved memory region and provide a debugfs entry to read
> +	  logs captured from this memory region and print them on console.
> +	  User can use below command to print the xbl log on console:
> +
> +                cat /sys/kernel/debug/xbl_log
> +
> +	  These logs help to identify firmware configuration information on
> +	  the SoC. The name of the built module will be dump_xbl_log
> +
>   endmenu
> diff --git a/drivers/soc/qcom/Makefile b/drivers/soc/qcom/Makefile
> index bbca2e1e55bb..aac088a1a0b6 100644
> --- a/drivers/soc/qcom/Makefile
> +++ b/drivers/soc/qcom/Makefile
> @@ -32,3 +32,4 @@ obj-$(CONFIG_QCOM_KRYO_L2_ACCESSORS) +=	kryo-l2-accessors.o
>   obj-$(CONFIG_QCOM_ICC_BWMON)	+= icc-bwmon.o
>   qcom_ice-objs			+= ice.o
>   obj-$(CONFIG_QCOM_INLINE_CRYPTO_ENGINE)	+= qcom_ice.o
> +obj-$(CONFIG_QCOM_DUMP_XBL_LOG)	+= dump_xbl_log.o
> diff --git a/drivers/soc/qcom/dump_xbl_log.c b/drivers/soc/qcom/dump_xbl_log.c
> new file mode 100644
> index 000000000000..ea335a5e660b
> --- /dev/null
> +++ b/drivers/soc/qcom/dump_xbl_log.c
> @@ -0,0 +1,139 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (c) 2021, The Linux Foundation. All rights reserved.
> + */
> +
> +#include <linux/init.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/device.h>
> +#include <linux/platform_device.h>
> +#include <linux/memblock.h>
> +#include <linux/of_address.h>
> +#include <linux/err.h>
> +#include <linux/debugfs.h>
> +
> +struct xbl_log_data {
> +	struct device *dev;
> +	size_t buf_size;
> +	void __iomem *xbl_buf;
> +	struct dentry *dbg_file;
> +	struct debugfs_blob_wrapper dbg_data;
> +};
> +
> +static int map_addr_range(struct device_node **parent, const char *name,
> +			  struct xbl_log_data *xbl_data)
> +{
> +	struct device_node *node;
> +	struct resource res;
> +	int ret;
> +
> +	node = of_find_node_by_name(*parent, name);
> +	if (!node)
> +		return -ENODEV;
> +
> +	ret = of_address_to_resource(node, 0, &res);
> +	if (ret) {
> +		dev_err(xbl_data->dev, "Failed to parse memory region\n");
> +		return ret;
> +	}
> +	of_node_put(node);
> +
> +	if (!resource_size(&res)) {
> +		dev_err(xbl_data->dev, "Failed to parse memory region size\n");
> +		return -ENODEV;
> +	}
> +
> +	xbl_data->buf_size = resource_size(&res) - 1;
> +	xbl_data->xbl_buf = devm_memremap(xbl_data->dev, res.start,
> +					  xbl_data->buf_size, MEMREMAP_WB);
> +	if (!xbl_data->xbl_buf) {
> +		dev_err(xbl_data->dev, "%s: memory remap failed\n", name);
> +		return -ENOMEM;
> +	}
> +
> +	return 0;
> +}
> +
> +static int xbl_log_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct xbl_log_data *xbl_data;
> +	struct device_node *parent;
> +	int ret;
> +
> +	xbl_data = devm_kzalloc(dev, sizeof(*xbl_data), GFP_KERNEL);
> +	if (!xbl_data)
> +		return -ENOMEM;
> +
> +	xbl_data->dev = &pdev->dev;
> +	platform_set_drvdata(pdev, xbl_data);
> +
> +	parent = of_find_node_by_path("/reserved-memory");
> +	if (!parent) {
> +		dev_err(xbl_data->dev, "reserved-memory node missing\n");
> +		return -ENODEV;
> +	}
> +
> +	ret = map_addr_range(&parent, "uefi-log", xbl_data);

This driver really needs a proper device tree bindings, rather than 
parsing the device tree manually here in the driver.

Pl look at ./Documentation/devicetree/bindings/reserved-memory/qcom*

This should also help you getting rid of all these parsing code.

--srini



> +	if (ret)
> +		goto put_node;
> +
> +	xbl_data->dbg_data.data = xbl_data->xbl_buf;
> +	xbl_data->dbg_data.size = xbl_data->buf_size;
> +	xbl_data->dbg_file = debugfs_create_blob("xbl_log", 0400, NULL,
> +						 &xbl_data->dbg_data);
> +	if (IS_ERR(xbl_data->dbg_file)) {
> +		dev_err(xbl_data->dev, "failed to create debugfs entry\n");
> +		ret = PTR_ERR(xbl_data->dbg_file);
> +	}
> +
> +put_node:
> +	of_node_put(parent);
> +	return ret;
> +}
> +
> +static int xbl_log_remove(struct platform_device *pdev)
> +{
> +	struct xbl_log_data *xbl_data = platform_get_drvdata(pdev);
> +
> +	debugfs_remove_recursive(xbl_data->dbg_file);
> +	return 0;
> +}
> +
> +static struct platform_driver xbl_log_driver = {
> +	.probe = xbl_log_probe,
> +	.remove = xbl_log_remove,
> +	.driver = {
> +		   .name = "xbl-log",
> +		   },
> +};
> +
> +static struct platform_device xbl_log_device = {
> +	.name = "xbl-log",
> +};
> +
> +static int __init xbl_log_init(void)
> +{
> +	int ret = 0;
> +
> +	ret = platform_driver_register(&xbl_log_driver);
> +	if (!ret) {
> +		ret = platform_device_register(&xbl_log_device);
> +		if (ret)
> +			platform_driver_unregister(&xbl_log_driver);
> +	}
> +	return ret;
> +}
> +
> +static void __exit xbl_log_exit(void)
> +{
> +	platform_device_unregister(&xbl_log_device);
> +	platform_driver_unregister(&xbl_log_driver);
> +}
> +
> +module_init(xbl_log_init);
> +module_exit(xbl_log_exit);
> +
> +MODULE_DESCRIPTION("Qualcomm Technologies, Inc. (QTI) XBL log driver");
> +MODULE_LICENSE("GPL");
Jeff Johnson Aug. 22, 2023, 3:14 p.m. UTC | #3 
On 8/22/2023 5:43 AM, Bryan O'Donoghue wrote:
> On 22/08/2023 13:15, Ninad Naik wrote:
..snip..
>> +// SPDX-License-Identifier: GPL-2.0-only
>> +/*
>> + * Copyright (c) 2021, The Linux Foundation. All rights reserved.
>> + */
> 
> 2023

if this is derived work based upon existing downstream code then I 
suspect the LF 2021 copyright is correct and should be maintained, and a 
QuIC 2023 copyright should be added
Trilok Soni Aug. 22, 2023, 4:08 p.m. UTC | #4 
On 8/22/2023 5:15 AM, Ninad Naik wrote:
> Qualcomm secondary bootloader (XBL) boot log holds information to
> identify various firmware configuration currently set on the SoC.
> The XBL log is stored in a predefined reserved memory region.

What does "X" stands for here? From what you have described above it 
looks like SBL and not XBL.

> 
> This drivers provides a way to print XBL logs on the console. To
> do so, it provides a debugfs entry which captures the logs stored
> in this reserved memory region. This entry can now be used to read
> and print the XBL logs to console.
> 
> User can use the below command to print XBL log to console:
>          cat /sys/kernel/debug/xbl_log


It is not clear to me why these patches are posted as RFC. Please 
clarify. Are they not tested properly or just seeking some feedback and 
driver is not ready w/ all the features?

> 
> Signed-off-by: Ninad Naik <quic_ninanaik@quicinc.com>
> ---
>   drivers/soc/qcom/Kconfig        |  13 +++
>   drivers/soc/qcom/Makefile       |   1 +
>   drivers/soc/qcom/dump_xbl_log.c | 139 ++++++++++++++++++++++++++++++++
>   3 files changed, 153 insertions(+)
>   create mode 100644 drivers/soc/qcom/dump_xbl_log.c
> 
> diff --git a/drivers/soc/qcom/Kconfig b/drivers/soc/qcom/Kconfig
> index 715348869d04..4489d37e924d 100644
> --- a/drivers/soc/qcom/Kconfig
> +++ b/drivers/soc/qcom/Kconfig
> @@ -291,4 +291,17 @@ config QCOM_INLINE_CRYPTO_ENGINE
>   	tristate
>   	select QCOM_SCM
>   
> +config QCOM_DUMP_XBL_LOG
> +	tristate "Qualcomm driver to print XBL logs on console from debugfs"

Why you want to print these logs from the debugfs? What is the format of 
the logs? Can you post an example log?

> +	help
> +	  This driver is used to capture secondary bootloader (xbl) log
> +	  from a reserved memory region and provide a debugfs entry to read
> +	  logs captured from this memory region and print them on console.
> +	  User can use below command to print the xbl log on console:
> +
> +                cat /sys/kernel/debug/xbl_log
> +
> +	  These logs help to identify firmware configuration information on
> +	  the SoC. The name of the built module will be dump_xbl_log
> +
>   endmenu
> diff --git a/drivers/soc/qcom/Makefile b/drivers/soc/qcom/Makefile
> index bbca2e1e55bb..aac088a1a0b6 100644
> --- a/drivers/soc/qcom/Makefile
> +++ b/drivers/soc/qcom/Makefile
> @@ -32,3 +32,4 @@ obj-$(CONFIG_QCOM_KRYO_L2_ACCESSORS) +=	kryo-l2-accessors.o
>   obj-$(CONFIG_QCOM_ICC_BWMON)	+= icc-bwmon.o
>   qcom_ice-objs			+= ice.o
>   obj-$(CONFIG_QCOM_INLINE_CRYPTO_ENGINE)	+= qcom_ice.o
> +obj-$(CONFIG_QCOM_DUMP_XBL_LOG)	+= dump_xbl_log.o
> diff --git a/drivers/soc/qcom/dump_xbl_log.c b/drivers/soc/qcom/dump_xbl_log.c
> new file mode 100644
> index 000000000000..ea335a5e660b
> --- /dev/null
> +++ b/drivers/soc/qcom/dump_xbl_log.c
> @@ -0,0 +1,139 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (c) 2021, The Linux Foundation. All rights reserved.
> + */
> +
> +#include <linux/init.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/device.h>
> +#include <linux/platform_device.h>
> +#include <linux/memblock.h>
> +#include <linux/of_address.h>
> +#include <linux/err.h>
> +#include <linux/debugfs.h>
> +
> +struct xbl_log_data {
> +	struct device *dev;
> +	size_t buf_size;
> +	void __iomem *xbl_buf;
> +	struct dentry *dbg_file;
> +	struct debugfs_blob_wrapper dbg_data;
> +};
> +
> +static int map_addr_range(struct device_node **parent, const char *name,
> +			  struct xbl_log_data *xbl_data)
> +{
> +	struct device_node *node;
> +	struct resource res;
> +	int ret;
> +
> +	node = of_find_node_by_name(*parent, name);
> +	if (!node)
> +		return -ENODEV;
> +
> +	ret = of_address_to_resource(node, 0, &res);
> +	if (ret) {
> +		dev_err(xbl_data->dev, "Failed to parse memory region\n");
> +		return ret;
> +	}
> +	of_node_put(node);
> +
> +	if (!resource_size(&res)) {
> +		dev_err(xbl_data->dev, "Failed to parse memory region size\n");
> +		return -ENODEV;
> +	}
> +
> +	xbl_data->buf_size = resource_size(&res) - 1;
> +	xbl_data->xbl_buf = devm_memremap(xbl_data->dev, res.start,
> +					  xbl_data->buf_size, MEMREMAP_WB);
> +	if (!xbl_data->xbl_buf) {
> +		dev_err(xbl_data->dev, "%s: memory remap failed\n", name);
> +		return -ENOMEM;
> +	}
> +
> +	return 0;
> +}
> +
> +static int xbl_log_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct xbl_log_data *xbl_data;
> +	struct device_node *parent;
> +	int ret;
> +
> +	xbl_data = devm_kzalloc(dev, sizeof(*xbl_data), GFP_KERNEL);
> +	if (!xbl_data)
> +		return -ENOMEM;
> +
> +	xbl_data->dev = &pdev->dev;
> +	platform_set_drvdata(pdev, xbl_data);
> +
> +	parent = of_find_node_by_path("/reserved-memory");
> +	if (!parent) {
> +		dev_err(xbl_data->dev, "reserved-memory node missing\n");
> +		return -ENODEV;
> +	}
> +
> +	ret = map_addr_range(&parent, "uefi-log", xbl_data);

Here you are calling it as uefi-log. Is it xbl-log or uefi-log? Please 
decide first.


> +	if (ret)
> +		goto put_node;
> +
> +	xbl_data->dbg_data.data = xbl_data->xbl_buf;
> +	xbl_data->dbg_data.size = xbl_data->buf_size;
> +	xbl_data->dbg_file = debugfs_create_blob("xbl_log", 0400, NULL,
> +						 &xbl_data->dbg_data);
> +	if (IS_ERR(xbl_data->dbg_file)) {
> +		dev_err(xbl_data->dev, "failed to create debugfs entry\n");
> +		ret = PTR_ERR(xbl_data->dbg_file);
> +	}
> +
> +put_node:
> +	of_node_put(parent);
> +	return ret;
> +}
> +
> +static int xbl_log_remove(struct platform_device *pdev)
> +{
> +	struct xbl_log_data *xbl_data = platform_get_drvdata(pdev);
> +
> +	debugfs_remove_recursive(xbl_data->dbg_file);
> +	return 0;
> +}
> +
> +static struct platform_driver xbl_log_driver = {
> +	.probe = xbl_log_probe,
> +	.remove = xbl_log_remove,
> +	.driver = {
> +		   .name = "xbl-log",
> +		   },
> +};
> +
> +static struct platform_device xbl_log_device = {
> +	.name = "xbl-log",
> +};
> +
> +static int __init xbl_log_init(void)
> +{
> +	int ret = 0;
> +
> +	ret = platform_driver_register(&xbl_log_driver);
> +	if (!ret) {
> +		ret = platform_device_register(&xbl_log_device);

I am puzzled here. Why?

> +		if (ret)
> +			platform_driver_unregister(&xbl_log_driver);
> +	}
> +	return ret;
> +}
> +
> +static void __exit xbl_log_exit(void)
> +{
> +	platform_device_unregister(&xbl_log_device);
> +	platform_driver_unregister(&xbl_log_driver);
> +}
> +
> +module_init(xbl_log_init);
> +module_exit(xbl_log_exit);
> +
> +MODULE_DESCRIPTION("Qualcomm Technologies, Inc. (QTI) XBL log driver");
> +MODULE_LICENSE("GPL");
Ninad Naik Aug. 23, 2023, 11:06 a.m. UTC | #5 
Hi Pavan,

On 8/22/2023 6:09 PM, Pavan Kondeti wrote:
> On Tue, Aug 22, 2023 at 05:45:12PM +0530, Ninad Naik wrote:
>> Qualcomm secondary bootloader (XBL) boot log holds information to
>> identify various firmware configuration currently set on the SoC.
>> The XBL log is stored in a predefined reserved memory region.
>>
>> This drivers provides a way to print XBL logs on the console. To
>> do so, it provides a debugfs entry which captures the logs stored
>> in this reserved memory region. This entry can now be used to read
>> and print the XBL logs to console.
>>
>> User can use the below command to print XBL log to console:
>>          cat /sys/kernel/debug/xbl_log
>>
>> Signed-off-by: Ninad Naik <quic_ninanaik@quicinc.com>
>> ---
> 
> For a single patch, cover letter may not be needed. The under cut
> portion (this area) of the patch can be used to present the additional
> details.
> 
Ack.
>>   drivers/soc/qcom/Kconfig        |  13 +++
>>   drivers/soc/qcom/Makefile       |   1 +
>>   drivers/soc/qcom/dump_xbl_log.c | 139 ++++++++++++++++++++++++++++++++
>>   3 files changed, 153 insertions(+)
>>   create mode 100644 drivers/soc/qcom/dump_xbl_log.c
>>
> 
> [...]
> 
>> +static int map_addr_range(struct device_node **parent, const char *name,
>> +			  struct xbl_log_data *xbl_data)
>> +{
>> +	struct device_node *node;
>> +	struct resource res;
>> +	int ret;
>> +
>> +	node = of_find_node_by_name(*parent, name);
>> +	if (!node)
>> +		return -ENODEV;
>> +
>> +	ret = of_address_to_resource(node, 0, &res);
>> +	if (ret) {
>> +		dev_err(xbl_data->dev, "Failed to parse memory region\n");
>> +		return ret;
>> +	}
>> +	of_node_put(node);
>> +
>> +	if (!resource_size(&res)) {
>> +		dev_err(xbl_data->dev, "Failed to parse memory region size\n");
>> +		return -ENODEV;
>> +	}
>> +
>> +	xbl_data->buf_size = resource_size(&res) - 1;
>> +	xbl_data->xbl_buf = devm_memremap(xbl_data->dev, res.start,
>> +					  xbl_data->buf_size, MEMREMAP_WB);
>> +	if (!xbl_data->xbl_buf) {
>> +		dev_err(xbl_data->dev, "%s: memory remap failed\n", name);
>> +		return -ENOMEM;
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>> +static int xbl_log_probe(struct platform_device *pdev)
>> +{
>> +	struct device *dev = &pdev->dev;
>> +	struct xbl_log_data *xbl_data;
>> +	struct device_node *parent;
>> +	int ret;
>> +
>> +	xbl_data = devm_kzalloc(dev, sizeof(*xbl_data), GFP_KERNEL);
>> +	if (!xbl_data)
>> +		return -ENOMEM;
>> +
>> +	xbl_data->dev = &pdev->dev;
>> +	platform_set_drvdata(pdev, xbl_data);
>> +
>> +	parent = of_find_node_by_path("/reserved-memory");
>> +	if (!parent) {
>> +		dev_err(xbl_data->dev, "reserved-memory node missing\n");
>> +		return -ENODEV;
>> +	}
>> +
> 
> You would need to present the Device Tree binding document for this. For
> ex: pls see
> Documentation/devicetree/bindings/reserved-memory/qcom,cmd-db.yaml
> 
Ack. Will add a corresponding DT binding in the next version
>> +	ret = map_addr_range(&parent, "uefi-log", xbl_data);
>> +	if (ret)
>> +		goto put_node;
>> +
>> +	xbl_data->dbg_data.data = xbl_data->xbl_buf;
>> +	xbl_data->dbg_data.size = xbl_data->buf_size;
>> +	xbl_data->dbg_file = debugfs_create_blob("xbl_log", 0400, NULL,
>> +						 &xbl_data->dbg_data);
>> +	if (IS_ERR(xbl_data->dbg_file)) {
>> +		dev_err(xbl_data->dev, "failed to create debugfs entry\n");
>> +		ret = PTR_ERR(xbl_data->dbg_file);
>> +	}
>> +
>> +put_node:
>> +	of_node_put(parent);
>> +	return ret;
>> +}
>> +
>> +static int xbl_log_remove(struct platform_device *pdev)
>> +{
>> +	struct xbl_log_data *xbl_data = platform_get_drvdata(pdev);
>> +
>> +	debugfs_remove_recursive(xbl_data->dbg_file);
>> +	return 0;
>> +}
>> +
>> +static struct platform_driver xbl_log_driver = {
>> +	.probe = xbl_log_probe,
>> +	.remove = xbl_log_remove,
>> +	.driver = {
>> +		   .name = "xbl-log",
>> +		   },
>> +};
>> +
>> +static struct platform_device xbl_log_device = {
>> +	.name = "xbl-log",
>> +};
>> +
>> +static int __init xbl_log_init(void)
>> +{
>> +	int ret = 0;
>> +
>> +	ret = platform_driver_register(&xbl_log_driver);
>> +	if (!ret) {
>> +		ret = platform_device_register(&xbl_log_device);
>> +		if (ret)
>> +			platform_driver_unregister(&xbl_log_driver);
>> +	}
>> +	return ret;
>> +}
>> +
> 
> The platform device registration, the resource parsing can be completely
> avoided by adding your compatible entry to reserved_mem_matches
> structure defined in drivers/of/platform.c . There are some Qualcomm SoC
> devices also present in that list.
> 
Ack. So once the compatible entry is added to reserved_mem_matches 
structure here, a platform_device is created for this node to which this 
driver can bind to. Thank you for the suggestion, I'll make the 
necessary corrections in the next revision.

>> +static void __exit xbl_log_exit(void)
>> +{
>> +	platform_device_unregister(&xbl_log_device);
>> +	platform_driver_unregister(&xbl_log_driver);
>> +}
>> +
>> +module_init(xbl_log_init);
>> +module_exit(xbl_log_exit);
>> +
>> +MODULE_DESCRIPTION("Qualcomm Technologies, Inc. (QTI) XBL log driver");
>> +MODULE_LICENSE("GPL");
>> -- 
>> 2.41.0
>>
Thanks,
Ninad
Ninad Naik Aug. 23, 2023, 11:08 a.m. UTC | #6 
Hi Bryan,

On 8/22/2023 6:13 PM, Bryan O'Donoghue wrote:
> On 22/08/2023 13:15, Ninad Naik wrote:
>> Qualcomm secondary bootloader (XBL) boot log holds information to
>> identify various firmware configuration currently set on the SoC.
>> The XBL log is stored in a predefined reserved memory region.
>>
>> This drivers provides a way to print XBL logs on the console. To
>> do so, it provides a debugfs entry which captures the logs stored
>> in this reserved memory region. This entry can now be used to read
>> and print the XBL logs to console.
>>
>> User can use the below command to print XBL log to console:
>>          cat /sys/kernel/debug/xbl_log
>>
>> Signed-off-by: Ninad Naik <quic_ninanaik@quicinc.com>
>> ---
>>   drivers/soc/qcom/Kconfig        |  13 +++
>>   drivers/soc/qcom/Makefile       |   1 +
>>   drivers/soc/qcom/dump_xbl_log.c | 139 ++++++++++++++++++++++++++++++++
>>   3 files changed, 153 insertions(+)
>>   create mode 100644 drivers/soc/qcom/dump_xbl_log.c
>>
>> diff --git a/drivers/soc/qcom/Kconfig b/drivers/soc/qcom/Kconfig
>> index 715348869d04..4489d37e924d 100644
>> --- a/drivers/soc/qcom/Kconfig
>> +++ b/drivers/soc/qcom/Kconfig
>> @@ -291,4 +291,17 @@ config QCOM_INLINE_CRYPTO_ENGINE
>>       tristate
>>       select QCOM_SCM
>> +config QCOM_DUMP_XBL_LOG
>> +    tristate "Qualcomm driver to print XBL logs on console from debugfs"
>> +    help
>> +      This driver is used to capture secondary bootloader (xbl) log
>> +      from a reserved memory region and provide a debugfs entry to read
>> +      logs captured from this memory region and print them on console.
>> +      User can use below command to print the xbl log on console:
>> +
>> +                cat /sys/kernel/debug/xbl_log
>> +
>> +      These logs help to identify firmware configuration information on
>> +      the SoC. The name of the built module will be dump_xbl_log
>> +
>>   endmenu
>> diff --git a/drivers/soc/qcom/Makefile b/drivers/soc/qcom/Makefile
>> index bbca2e1e55bb..aac088a1a0b6 100644
>> --- a/drivers/soc/qcom/Makefile
>> +++ b/drivers/soc/qcom/Makefile
>> @@ -32,3 +32,4 @@ obj-$(CONFIG_QCOM_KRYO_L2_ACCESSORS) +=    
>> kryo-l2-accessors.o
>>   obj-$(CONFIG_QCOM_ICC_BWMON)    += icc-bwmon.o
>>   qcom_ice-objs            += ice.o
>>   obj-$(CONFIG_QCOM_INLINE_CRYPTO_ENGINE)    += qcom_ice.o
>> +obj-$(CONFIG_QCOM_DUMP_XBL_LOG)    += dump_xbl_log.o
>> diff --git a/drivers/soc/qcom/dump_xbl_log.c 
>> b/drivers/soc/qcom/dump_xbl_log.c
>> new file mode 100644
>> index 000000000000..ea335a5e660b
>> --- /dev/null
>> +++ b/drivers/soc/qcom/dump_xbl_log.c
>> @@ -0,0 +1,139 @@
>> +// SPDX-License-Identifier: GPL-2.0-only
>> +/*
>> + * Copyright (c) 2021, The Linux Foundation. All rights reserved.
>> + */
> 
> 2023
> 
>> +
>> +#include <linux/init.h>
>> +#include <linux/module.h>
>> +#include <linux/of.h>
>> +#include <linux/device.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/memblock.h>
>> +#include <linux/of_address.h>
>> +#include <linux/err.h>
>> +#include <linux/debugfs.h>
> 
> It would be nice to alphetise this include list.
> 
Ack. Sure, I'll make this fix. Thank you.
>> +struct xbl_log_data {
>> +    struct device *dev;
>> +    size_t buf_size;
>> +    void __iomem *xbl_buf;
>> +    struct dentry *dbg_file;
>> +    struct debugfs_blob_wrapper dbg_data;
>> +};
>> +
>> +static int map_addr_range(struct device_node **parent, const char *name,
>> +              struct xbl_log_data *xbl_data)
>> +{
>> +    struct device_node *node;
>> +    struct resource res;
>> +    int ret;
>> +
>> +    node = of_find_node_by_name(*parent, name);
>> +    if (!node)
>> +        return -ENODEV;
>> +
>> +    ret = of_address_to_resource(node, 0, &res);
>> +    if (ret) {
>> +        dev_err(xbl_data->dev, "Failed to parse memory region\n");
>> +        return ret;
>> +    }
>> +    of_node_put(node);
>> +
>> +    if (!resource_size(&res)) {
>> +        dev_err(xbl_data->dev, "Failed to parse memory region size\n");
>> +        return -ENODEV;
>> +    }
>> +
>> +    xbl_data->buf_size = resource_size(&res) - 1;
>> +    xbl_data->xbl_buf = devm_memremap(xbl_data->dev, res.start,
>> +                      xbl_data->buf_size, MEMREMAP_WB);
>> +    if (!xbl_data->xbl_buf) {
>> +        dev_err(xbl_data->dev, "%s: memory remap failed\n", name);
>> +        return -ENOMEM;
>> +    }
>> +
>> +    return 0;
>> +}
>> +
>> +static int xbl_log_probe(struct platform_device *pdev)
>> +{
>> +    struct device *dev = &pdev->dev;
>> +    struct xbl_log_data *xbl_data;
>> +    struct device_node *parent;
>> +    int ret;
>> +
>> +    xbl_data = devm_kzalloc(dev, sizeof(*xbl_data), GFP_KERNEL);
>> +    if (!xbl_data)
>> +        return -ENOMEM;
>> +
>> +    xbl_data->dev = &pdev->dev;
>> +    platform_set_drvdata(pdev, xbl_data);
>> +
>> +    parent = of_find_node_by_path("/reserved-memory");
>> +    if (!parent) {
>> +        dev_err(xbl_data->dev, "reserved-memory node missing\n");
>> +        return -ENODEV;
>> +    }
>> +
>> +    ret = map_addr_range(&parent, "uefi-log", xbl_data);
>> +    if (ret)
>> +        goto put_node;
>> +
>> +    xbl_data->dbg_data.data = xbl_data->xbl_buf;
>> +    xbl_data->dbg_data.size = xbl_data->buf_size;
>> +    xbl_data->dbg_file = debugfs_create_blob("xbl_log", 0400, NULL,
>> +                         &xbl_data->dbg_data);
>> +    if (IS_ERR(xbl_data->dbg_file)) {
>> +        dev_err(xbl_data->dev, "failed to create debugfs entry\n");
>> +        ret = PTR_ERR(xbl_data->dbg_file);
>> +    }
>> +
>> +put_node:
>> +    of_node_put(parent);
>> +    return ret;
>> +}
>> +
>> +static int xbl_log_remove(struct platform_device *pdev)
>> +{
>> +    struct xbl_log_data *xbl_data = platform_get_drvdata(pdev);
>> +
>> +    debugfs_remove_recursive(xbl_data->dbg_file);
>> +    return 0;
>> +}
>> +
>> +static struct platform_driver xbl_log_driver = {
>> +    .probe = xbl_log_probe,
>> +    .remove = xbl_log_remove,
>> +    .driver = {
>> +           .name = "xbl-log",
>> +           },
> Is that indentation correct ?
>
No, the closing parenthesis should be fixed. Will correct this, thank you.

>> +};
>> +
>> +static struct platform_device xbl_log_device = {
>> +    .name = "xbl-log",
>> +};
>> +
>> +static int __init xbl_log_init(void)
>> +{
>> +    int ret = 0;
>> +
>> +    ret = platform_driver_register(&xbl_log_driver);
>> +    if (!ret) {
>> +        ret = platform_device_register(&xbl_log_device);
>> +        if (ret)
>> +            platform_driver_unregister(&xbl_log_driver);
>> +    }
>> +    return ret;
>> +}
>> +
>> +static void __exit xbl_log_exit(void)
>> +{
>> +    platform_device_unregister(&xbl_log_device);
>> +    platform_driver_unregister(&xbl_log_driver);
>> +}
>> +
>> +module_init(xbl_log_init);
>> +module_exit(xbl_log_exit);
>> +
>> +MODULE_DESCRIPTION("Qualcomm Technologies, Inc. (QTI) XBL log driver");
>> +MODULE_LICENSE("GPL");
> 
> ---
> bod
Thanks,
Ninad
Ninad Naik Aug. 23, 2023, 11:09 a.m. UTC | #7 
Hi Srinivas,

On 8/22/2023 7:11 PM, Srinivas Kandagatla wrote:
> 
> 
> On 22/08/2023 13:15, Ninad Naik wrote:
>> Qualcomm secondary bootloader (XBL) boot log holds information to
>> identify various firmware configuration currently set on the SoC.
>> The XBL log is stored in a predefined reserved memory region.
>>
>> This drivers provides a way to print XBL logs on the console. To
>> do so, it provides a debugfs entry which captures the logs stored
>> in this reserved memory region. This entry can now be used to read
>> and print the XBL logs to console.
>>
>> User can use the below command to print XBL log to console:
>>          cat /sys/kernel/debug/xbl_log
>>
>> Signed-off-by: Ninad Naik <quic_ninanaik@quicinc.com>
>> ---
>>   drivers/soc/qcom/Kconfig        |  13 +++
>>   drivers/soc/qcom/Makefile       |   1 +
>>   drivers/soc/qcom/dump_xbl_log.c | 139 ++++++++++++++++++++++++++++++++
>>   3 files changed, 153 insertions(+)
>>   create mode 100644 drivers/soc/qcom/dump_xbl_log.c
>>
>> diff --git a/drivers/soc/qcom/Kconfig b/drivers/soc/qcom/Kconfig
>> index 715348869d04..4489d37e924d 100644
>> --- a/drivers/soc/qcom/Kconfig
>> +++ b/drivers/soc/qcom/Kconfig
>> @@ -291,4 +291,17 @@ config QCOM_INLINE_CRYPTO_ENGINE
>>       tristate
>>       select QCOM_SCM
>> +config QCOM_DUMP_XBL_LOG
>> +    tristate "Qualcomm driver to print XBL logs on console from debugfs"
>> +    help
>> +      This driver is used to capture secondary bootloader (xbl) log
>> +      from a reserved memory region and provide a debugfs entry to read
>> +      logs captured from this memory region and print them on console.
>> +      User can use below command to print the xbl log on console:
>> +
>> +                cat /sys/kernel/debug/xbl_log
>> +
>> +      These logs help to identify firmware configuration information on
>> +      the SoC. The name of the built module will be dump_xbl_log
>> +
>>   endmenu
>> diff --git a/drivers/soc/qcom/Makefile b/drivers/soc/qcom/Makefile
>> index bbca2e1e55bb..aac088a1a0b6 100644
>> --- a/drivers/soc/qcom/Makefile
>> +++ b/drivers/soc/qcom/Makefile
>> @@ -32,3 +32,4 @@ obj-$(CONFIG_QCOM_KRYO_L2_ACCESSORS) +=    
>> kryo-l2-accessors.o
>>   obj-$(CONFIG_QCOM_ICC_BWMON)    += icc-bwmon.o
>>   qcom_ice-objs            += ice.o
>>   obj-$(CONFIG_QCOM_INLINE_CRYPTO_ENGINE)    += qcom_ice.o
>> +obj-$(CONFIG_QCOM_DUMP_XBL_LOG)    += dump_xbl_log.o
>> diff --git a/drivers/soc/qcom/dump_xbl_log.c 
>> b/drivers/soc/qcom/dump_xbl_log.c
>> new file mode 100644
>> index 000000000000..ea335a5e660b
>> --- /dev/null
>> +++ b/drivers/soc/qcom/dump_xbl_log.c
>> @@ -0,0 +1,139 @@
>> +// SPDX-License-Identifier: GPL-2.0-only
>> +/*
>> + * Copyright (c) 2021, The Linux Foundation. All rights reserved.
>> + */
>> +
>> +#include <linux/init.h>
>> +#include <linux/module.h>
>> +#include <linux/of.h>
>> +#include <linux/device.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/memblock.h>
>> +#include <linux/of_address.h>
>> +#include <linux/err.h>
>> +#include <linux/debugfs.h>
>> +
>> +struct xbl_log_data {
>> +    struct device *dev;
>> +    size_t buf_size;
>> +    void __iomem *xbl_buf;
>> +    struct dentry *dbg_file;
>> +    struct debugfs_blob_wrapper dbg_data;
>> +};
>> +
>> +static int map_addr_range(struct device_node **parent, const char *name,
>> +              struct xbl_log_data *xbl_data)
>> +{
>> +    struct device_node *node;
>> +    struct resource res;
>> +    int ret;
>> +
>> +    node = of_find_node_by_name(*parent, name);
>> +    if (!node)
>> +        return -ENODEV;
>> +
>> +    ret = of_address_to_resource(node, 0, &res);
>> +    if (ret) {
>> +        dev_err(xbl_data->dev, "Failed to parse memory region\n");
>> +        return ret;
>> +    }
>> +    of_node_put(node);
>> +
>> +    if (!resource_size(&res)) {
>> +        dev_err(xbl_data->dev, "Failed to parse memory region size\n");
>> +        return -ENODEV;
>> +    }
>> +
>> +    xbl_data->buf_size = resource_size(&res) - 1;
>> +    xbl_data->xbl_buf = devm_memremap(xbl_data->dev, res.start,
>> +                      xbl_data->buf_size, MEMREMAP_WB);
>> +    if (!xbl_data->xbl_buf) {
>> +        dev_err(xbl_data->dev, "%s: memory remap failed\n", name);
>> +        return -ENOMEM;
>> +    }
>> +
>> +    return 0;
>> +}
>> +
>> +static int xbl_log_probe(struct platform_device *pdev)
>> +{
>> +    struct device *dev = &pdev->dev;
>> +    struct xbl_log_data *xbl_data;
>> +    struct device_node *parent;
>> +    int ret;
>> +
>> +    xbl_data = devm_kzalloc(dev, sizeof(*xbl_data), GFP_KERNEL);
>> +    if (!xbl_data)
>> +        return -ENOMEM;
>> +
>> +    xbl_data->dev = &pdev->dev;
>> +    platform_set_drvdata(pdev, xbl_data);
>> +
>> +    parent = of_find_node_by_path("/reserved-memory");
>> +    if (!parent) {
>> +        dev_err(xbl_data->dev, "reserved-memory node missing\n");
>> +        return -ENODEV;
>> +    }
>> +
>> +    ret = map_addr_range(&parent, "uefi-log", xbl_data);
> 
> This driver really needs a proper device tree bindings, rather than 
> parsing the device tree manually here in the driver.
> 
> Pl look at ./Documentation/devicetree/bindings/reserved-memory/qcom*
> 
> This should also help you getting rid of all these parsing code.
> 
> --srini
>
Ack. I'll add a device tree binding and make corresponding fixes without 
the parsing and device registration, taking this link as well as Pavan's 
suggestion of adding the compatible entry to the reserved_mem_matches 
table in consideration. Thank you.>
> 
>> +    if (ret)
>> +        goto put_node;
>> +
>> +    xbl_data->dbg_data.data = xbl_data->xbl_buf;
>> +    xbl_data->dbg_data.size = xbl_data->buf_size;
>> +    xbl_data->dbg_file = debugfs_create_blob("xbl_log", 0400, NULL,
>> +                         &xbl_data->dbg_data);
>> +    if (IS_ERR(xbl_data->dbg_file)) {
>> +        dev_err(xbl_data->dev, "failed to create debugfs entry\n");
>> +        ret = PTR_ERR(xbl_data->dbg_file);
>> +    }
>> +
>> +put_node:
>> +    of_node_put(parent);
>> +    return ret;
>> +}
>> +
>> +static int xbl_log_remove(struct platform_device *pdev)
>> +{
>> +    struct xbl_log_data *xbl_data = platform_get_drvdata(pdev);
>> +
>> +    debugfs_remove_recursive(xbl_data->dbg_file);
>> +    return 0;
>> +}
>> +
>> +static struct platform_driver xbl_log_driver = {
>> +    .probe = xbl_log_probe,
>> +    .remove = xbl_log_remove,
>> +    .driver = {
>> +           .name = "xbl-log",
>> +           },
>> +};
>> +
>> +static struct platform_device xbl_log_device = {
>> +    .name = "xbl-log",
>> +};
>> +
>> +static int __init xbl_log_init(void)
>> +{
>> +    int ret = 0;
>> +
>> +    ret = platform_driver_register(&xbl_log_driver);
>> +    if (!ret) {
>> +        ret = platform_device_register(&xbl_log_device);
>> +        if (ret)
>> +            platform_driver_unregister(&xbl_log_driver);
>> +    }
>> +    return ret;
>> +}
>> +
>> +static void __exit xbl_log_exit(void)
>> +{
>> +    platform_device_unregister(&xbl_log_device);
>> +    platform_driver_unregister(&xbl_log_driver);
>> +}
>> +
>> +module_init(xbl_log_init);
>> +module_exit(xbl_log_exit);
>> +
>> +MODULE_DESCRIPTION("Qualcomm Technologies, Inc. (QTI) XBL log driver");
>> +MODULE_LICENSE("GPL");

Thanks,
Ninad
diff mbox series

Patch

diff --git a/drivers/soc/qcom/Kconfig b/drivers/soc/qcom/Kconfig
index 715348869d04..4489d37e924d 100644
--- a/drivers/soc/qcom/Kconfig
+++ b/drivers/soc/qcom/Kconfig
@@ -291,4 +291,17 @@  config QCOM_INLINE_CRYPTO_ENGINE
 	tristate
 	select QCOM_SCM
 
+config QCOM_DUMP_XBL_LOG
+	tristate "Qualcomm driver to print XBL logs on console from debugfs"
+	help
+	  This driver is used to capture secondary bootloader (xbl) log
+	  from a reserved memory region and provide a debugfs entry to read
+	  logs captured from this memory region and print them on console.
+	  User can use below command to print the xbl log on console:
+
+                cat /sys/kernel/debug/xbl_log
+
+	  These logs help to identify firmware configuration information on
+	  the SoC. The name of the built module will be dump_xbl_log
+
 endmenu
diff --git a/drivers/soc/qcom/Makefile b/drivers/soc/qcom/Makefile
index bbca2e1e55bb..aac088a1a0b6 100644
--- a/drivers/soc/qcom/Makefile
+++ b/drivers/soc/qcom/Makefile
@@ -32,3 +32,4 @@  obj-$(CONFIG_QCOM_KRYO_L2_ACCESSORS) +=	kryo-l2-accessors.o
 obj-$(CONFIG_QCOM_ICC_BWMON)	+= icc-bwmon.o
 qcom_ice-objs			+= ice.o
 obj-$(CONFIG_QCOM_INLINE_CRYPTO_ENGINE)	+= qcom_ice.o
+obj-$(CONFIG_QCOM_DUMP_XBL_LOG)	+= dump_xbl_log.o
diff --git a/drivers/soc/qcom/dump_xbl_log.c b/drivers/soc/qcom/dump_xbl_log.c
new file mode 100644
index 000000000000..ea335a5e660b
--- /dev/null
+++ b/drivers/soc/qcom/dump_xbl_log.c
@@ -0,0 +1,139 @@ 
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2021, The Linux Foundation. All rights reserved.
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/device.h>
+#include <linux/platform_device.h>
+#include <linux/memblock.h>
+#include <linux/of_address.h>
+#include <linux/err.h>
+#include <linux/debugfs.h>
+
+struct xbl_log_data {
+	struct device *dev;
+	size_t buf_size;
+	void __iomem *xbl_buf;
+	struct dentry *dbg_file;
+	struct debugfs_blob_wrapper dbg_data;
+};
+
+static int map_addr_range(struct device_node **parent, const char *name,
+			  struct xbl_log_data *xbl_data)
+{
+	struct device_node *node;
+	struct resource res;
+	int ret;
+
+	node = of_find_node_by_name(*parent, name);
+	if (!node)
+		return -ENODEV;
+
+	ret = of_address_to_resource(node, 0, &res);
+	if (ret) {
+		dev_err(xbl_data->dev, "Failed to parse memory region\n");
+		return ret;
+	}
+	of_node_put(node);
+
+	if (!resource_size(&res)) {
+		dev_err(xbl_data->dev, "Failed to parse memory region size\n");
+		return -ENODEV;
+	}
+
+	xbl_data->buf_size = resource_size(&res) - 1;
+	xbl_data->xbl_buf = devm_memremap(xbl_data->dev, res.start,
+					  xbl_data->buf_size, MEMREMAP_WB);
+	if (!xbl_data->xbl_buf) {
+		dev_err(xbl_data->dev, "%s: memory remap failed\n", name);
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+static int xbl_log_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct xbl_log_data *xbl_data;
+	struct device_node *parent;
+	int ret;
+
+	xbl_data = devm_kzalloc(dev, sizeof(*xbl_data), GFP_KERNEL);
+	if (!xbl_data)
+		return -ENOMEM;
+
+	xbl_data->dev = &pdev->dev;
+	platform_set_drvdata(pdev, xbl_data);
+
+	parent = of_find_node_by_path("/reserved-memory");
+	if (!parent) {
+		dev_err(xbl_data->dev, "reserved-memory node missing\n");
+		return -ENODEV;
+	}
+
+	ret = map_addr_range(&parent, "uefi-log", xbl_data);
+	if (ret)
+		goto put_node;
+
+	xbl_data->dbg_data.data = xbl_data->xbl_buf;
+	xbl_data->dbg_data.size = xbl_data->buf_size;
+	xbl_data->dbg_file = debugfs_create_blob("xbl_log", 0400, NULL,
+						 &xbl_data->dbg_data);
+	if (IS_ERR(xbl_data->dbg_file)) {
+		dev_err(xbl_data->dev, "failed to create debugfs entry\n");
+		ret = PTR_ERR(xbl_data->dbg_file);
+	}
+
+put_node:
+	of_node_put(parent);
+	return ret;
+}
+
+static int xbl_log_remove(struct platform_device *pdev)
+{
+	struct xbl_log_data *xbl_data = platform_get_drvdata(pdev);
+
+	debugfs_remove_recursive(xbl_data->dbg_file);
+	return 0;
+}
+
+static struct platform_driver xbl_log_driver = {
+	.probe = xbl_log_probe,
+	.remove = xbl_log_remove,
+	.driver = {
+		   .name = "xbl-log",
+		   },
+};
+
+static struct platform_device xbl_log_device = {
+	.name = "xbl-log",
+};
+
+static int __init xbl_log_init(void)
+{
+	int ret = 0;
+
+	ret = platform_driver_register(&xbl_log_driver);
+	if (!ret) {
+		ret = platform_device_register(&xbl_log_device);
+		if (ret)
+			platform_driver_unregister(&xbl_log_driver);
+	}
+	return ret;
+}
+
+static void __exit xbl_log_exit(void)
+{
+	platform_device_unregister(&xbl_log_device);
+	platform_driver_unregister(&xbl_log_driver);
+}
+
+module_init(xbl_log_init);
+module_exit(xbl_log_exit);
+
+MODULE_DESCRIPTION("Qualcomm Technologies, Inc. (QTI) XBL log driver");
+MODULE_LICENSE("GPL");