Messages in this thread | | | Date | Fri, 14 Apr 2023 12:34:09 +0100 | Subject | Re: [PATCH V3 2/3] soc: qcom: boot_stat: Add Driver Support for Boot Stats | From | Srinivas Kandagatla <> |
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On 13/04/2023 10:28, Souradeep Chowdhury wrote: > All of Qualcomm's proprietary Android boot-loaders capture boot time > stats, like the time when the bootloader started execution and at what > point the bootloader handed over control to the kernel etc. in the IMEM > region. This information is captured in a specific format by this driver > by mapping a structure to the IMEM memory region and then accessing the > members of the structure to show the information within debugfs file. > This information is useful in verifying if the existing boot KPIs have > regressed or not. The information is shown in milliseconds, a sample > log from sm8450(waipio) device is as follows:- > > /sys/kernel/debug/146aa6b0.boot_stats # cat abl_time > 17898 ms > /sys/kernel/debug/146aa6b0.boot_stats # cat pre_abl_time > 2879 ms > > The Module Power Manager(MPM) sleep counter starts ticking at the PBL > stage and the timestamp generated by the sleep counter is logged by > the Qualcomm proprietary bootloader(ABL) at two points-> First when it > starts execution which is logged here as "pre_abl_time" and the second > when it is about to load the kernel logged as "abl_time". Documentation > details are also added in Documentation/ABI/testing/debugfs-driver-bootstat > > Signed-off-by: Souradeep Chowdhury <quic_schowdhu@quicinc.com> > --- > Documentation/ABI/testing/debugfs-driver-bootstat | 17 ++++ > drivers/soc/qcom/Kconfig | 9 ++ > drivers/soc/qcom/Makefile | 1 + > drivers/soc/qcom/boot_stats.c | 109 ++++++++++++++++++++++ > 4 files changed, 136 insertions(+) > create mode 100644 Documentation/ABI/testing/debugfs-driver-bootstat > create mode 100644 drivers/soc/qcom/boot_stats.c > > diff --git a/Documentation/ABI/testing/debugfs-driver-bootstat b/Documentation/ABI/testing/debugfs-driver-bootstat > new file mode 100644 > index 0000000..37d8e32 > --- /dev/null > +++ b/Documentation/ABI/testing/debugfs-driver-bootstat > @@ -0,0 +1,17 @@ > +What: /sys/kernel/debug/...stats/pre_abl_time > +Date: April 2023 > +Contact: Souradeep Chowdhury <quic_schowdhu@quicinc.com> > +Description: > + This file is used to read the KPI value pre abl time. > + It shows the time in milliseconds from the starting > + point of PBL to the point when the control shifted > + to ABL(Qualcomm proprietary bootloader). > + > +What: /sys/kernel/debug/...stats/abl_time > +Date: April 2023 > +Contact: Souradeep Chowdhury <quic_schowdhu@quicinc.com> > +Description: > + This file is used to read the KPI value abl time. > + It show the duration in milliseconds from the > + time control switched to ABL to the point when > + the linux kernel started getting loaded. > diff --git a/drivers/soc/qcom/Kconfig b/drivers/soc/qcom/Kconfig > index a8f2830..0d2cbd3 100644 > --- a/drivers/soc/qcom/Kconfig > +++ b/drivers/soc/qcom/Kconfig > @@ -16,6 +16,15 @@ config QCOM_AOSS_QMP > subsystems as well as controlling the debug clocks exposed by the Always On > Subsystem (AOSS) using Qualcomm Messaging Protocol (QMP). > > +config QCOM_BOOTSTAT > + tristate "Qualcomm Technologies, Boot Stat driver" > + depends on ARCH_QCOM || COMPILE_TEST > + help > + This option enables driver support for boot stats. Boot stat driver logs > + the kernel bootloader information by accessing the imem region. These > + information is exposed in the form of debugfs files. This is used to > + determine if there is any regression in boot timings. > + > config QCOM_COMMAND_DB > tristate "Qualcomm Command DB" > depends on ARCH_QCOM || COMPILE_TEST > diff --git a/drivers/soc/qcom/Makefile b/drivers/soc/qcom/Makefile > index 6e88da8..bdaa41a 100644 > --- a/drivers/soc/qcom/Makefile > +++ b/drivers/soc/qcom/Makefile > @@ -1,6 +1,7 @@ > # SPDX-License-Identifier: GPL-2.0 > CFLAGS_rpmh-rsc.o := -I$(src) > obj-$(CONFIG_QCOM_AOSS_QMP) += qcom_aoss.o > +obj-$(CONFIG_QCOM_BOOTSTAT) += boot_stats.o > obj-$(CONFIG_QCOM_GENI_SE) += qcom-geni-se.o > obj-$(CONFIG_QCOM_COMMAND_DB) += cmd-db.o > obj-$(CONFIG_QCOM_CPR) += cpr.o > diff --git a/drivers/soc/qcom/boot_stats.c b/drivers/soc/qcom/boot_stats.c > new file mode 100644 > index 0000000..9b65aa1 > --- /dev/null > +++ b/drivers/soc/qcom/boot_stats.c > @@ -0,0 +1,109 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +/* > + * Copyright (c) 2013-2019, 2021 The Linux Foundation. All rights reserved. > + * Copyright (c) 2023 Qualcomm Innovation Center, Inc. All rights reserved. > + */ > + > +#include <linux/debugfs.h> > +#include <linux/err.h> > +#include <linux/io.h> > +#include <linux/init.h> > +#include <linux/kernel.h> > +#include <linux/module.h> > +#include <linux/of.h> > +#include <linux/of_address.h> > +#include <linux/platform_device.h> > + > +#define TO_MS(timestamp) ((timestamp * 1000) / 32768) > + > +/** > + * struct boot_stats - timestamp information related to boot stats > + * @abl_start: Time for the starting point of the abl > + * @abl_end: Time when the kernel starts loading from abl > + */ > +struct boot_stats { > + u32 abl_start; > + u32 abl_end; > +} __packed; > + > +static struct boot_stats __iomem *boot_stats; > +static struct dentry *dbg_dir; > + I would avoid global variables where possible, and allocate them dynamically.
In this case you could do that in probe and pass it(boot_stats) as argument to debugfs_create_file() and also set dbg_dir as dev_set_drvdata to be able to use it in remove.
----------------->cut<-------------- > +static ssize_t abl_read(struct file *filp, char __user *userbuf, > + size_t count, loff_t *ppos) > +{ > + char buf[20]; > + > + u32 abl_time = TO_MS(boot_stats->abl_end) - TO_MS(boot_stats->abl_start); > + > + sprintf(buf, "%u ms\n", abl_time); > + return simple_read_from_buffer(userbuf, count, ppos, buf, strlen(buf)); > +} > + > +static const struct file_operations abl_fops = { > + .read = abl_read, > + .open = simple_open, > + .llseek = generic_file_llseek, > +}; > + --------------->cut<---------------- can be replaced with.
static int abl_show(struct seq_file *s_file, void *data) { struct boot_stats *boot_stats = s_file->private; ... }
DEFINE_SHOW_ATTRIBUTE(abl);
> +static ssize_t pre_abl_read(struct file *filp, char __user *userbuf, > + size_t count, loff_t *ppos) > +{ > + char buf[20]; > + > + sprintf(buf, "%u ms\n", TO_MS(boot_stats->abl_start)); > + return simple_read_from_buffer(userbuf, count, ppos, buf, strlen(buf)); > +} > + > +static const struct file_operations pre_abl_fops = { > + .read = pre_abl_read, > + .open = simple_open, > + .llseek = generic_file_llseek, > +}; > + same here.
> +static int boot_stats_probe(struct platform_device *pdev) > +{ > + struct device *boot_stat = &pdev->dev; > + > + dbg_dir = debugfs_create_dir(dev_name(&pdev->dev), NULL); > + if (IS_ERR(dbg_dir)) > + return dev_err_probe(&pdev->dev, -ENOENT, > + "failed to create debugfs directory"); > + > + boot_stats = of_iomap(boot_stat->of_node, 0);
may be devm_of_iomap?
> + if (!boot_stats) > + return dev_err_probe(&pdev->dev, -ENOMEM, > + "failed to map imem region\n"); > + > + debugfs_create_file("pre_abl_time", 0200, dbg_dir, NULL, &pre_abl_fops); > + debugfs_create_file("abl_time", 0200, dbg_dir, NULL, &abl_fops); > + > + return 0; > +} > + > +static int boot_stats_remove(struct platform_device *pdev) > +{ > + debugfs_remove_recursive(dbg_dir); > + iounmap(boot_stats); > + > + return 0; > +} > + > +static const struct of_device_id boot_stats_dt_match[] = { > + { .compatible = "qcom,sm8450-bootstats" }, > + { } > +}; > +MODULE_DEVICE_TABLE(of, boot_stats_dt_match); > + > +static struct platform_driver boot_stat_driver = { > + .probe = boot_stats_probe, > + .remove = boot_stats_remove,
consider using remove_new as its suggested that new drivers implement .remove_new as it returns void. more details in include/linux/platform_device.h
-srini
> + .driver = { > + .name = "qcom-boot-stats", > + .of_match_table = boot_stats_dt_match, > + }, > +}; > +module_platform_driver(boot_stat_driver); > + > +MODULE_DESCRIPTION("Qualcomm Technologies Inc. Boot Stat driver"); > +MODULE_LICENSE("GPL"); > -- > 2.7.4 >
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