Message-ID: <0802823a-4be2-6d55-b259-5084a809c7bb@codeaurora.org>
Date:   Mon, 18 Oct 2021 19:45:30 +0530
From:   Maulik Shah <mkshah@...eaurora.org>
To:     Shawn Guo <shawn.guo@...aro.org>
Cc:     swboyd@...omium.org, mka@...omium.org, evgreen@...omium.org,
        bjorn.andersson@...aro.org, linux-arm-msm@...r.kernel.org,
        linux-kernel@...r.kernel.org, agross@...nel.org,
        dianders@...omium.org, linux@...ck-us.net, rnayak@...eaurora.org,
        lsrao@...eaurora.org,
        Mahesh Sivasubramanian <msivasub@...eaurora.org>,
        Lina Iyer <ilina@...eaurora.org>
Subject: Re: [PATCH v12 2/5] soc: qcom: Add Sleep stats driver

Hi Shawn,

On 10/15/2021 7:28 PM, Shawn Guo wrote:
> Hi Mahesh,
> 
> Thanks for the work!
> 
> While I tested it good on SDM660 and MSM8939, I have a question
> regarding 'vlow' mode below.
> 
> On Wed, Oct 13, 2021 at 12:08:21PM +0530, Maulik Shah wrote:
>> From: Mahesh Sivasubramanian <msivasub@...eaurora.org>
>>
>> Let's add a driver to read the stats from remote processor and
>> export to debugfs.
>>
>> The driver creates "qcom_sleep_stats" directory in debugfs and
>> adds files for various low power mode available. Below is sample
>> output with command
>>
>> cat /sys/kernel/debug/qcom_sleep_stats/ddr
>> count = 0
>> Last Entered At = 0
>> Last Exited At = 0
>> Accumulated Duration = 0
>>
>> Signed-off-by: Mahesh Sivasubramanian <msivasub@...eaurora.org>
>> Signed-off-by: Lina Iyer <ilina@...eaurora.org>
>> [mkshah: add subsystem sleep stats, create one file for each stat]
>> Signed-off-by: Maulik Shah <mkshah@...eaurora.org>
>> ---
>>   drivers/soc/qcom/Kconfig      |  10 ++
>>   drivers/soc/qcom/Makefile     |   1 +
>>   drivers/soc/qcom/qcom_stats.c | 277 ++++++++++++++++++++++++++++++++++++++++++
>>   3 files changed, 288 insertions(+)
>>   create mode 100644 drivers/soc/qcom/qcom_stats.c
>>
>> diff --git a/drivers/soc/qcom/Kconfig b/drivers/soc/qcom/Kconfig
>> index abfef20..3cf3a6b 100644
>> --- a/drivers/soc/qcom/Kconfig
>> +++ b/drivers/soc/qcom/Kconfig
>> @@ -199,6 +199,16 @@ config QCOM_SPM
>>   	  to manage cores, L2 low power modes and to configure the internal
>>   	  Adaptive Voltage Scaler parameters, where supported.
>>   
>> +config QCOM_STATS
>> +	tristate "Qualcomm Technologies, Inc. (QTI) Sleep stats driver"
>> +	depends on (ARCH_QCOM && DEBUG_FS) || COMPILE_TEST
>> +	depends on QCOM_SMEM
>> +	help
>> +	  Qualcomm Technologies, Inc. (QTI) Sleep stats driver to read
>> +	  the shared memory exported by the remote processor related to
>> +	  various SoC level low power modes statistics and export to debugfs
>> +	  interface.
>> +
>>   config QCOM_WCNSS_CTRL
>>   	tristate "Qualcomm WCNSS control driver"
>>   	depends on ARCH_QCOM || COMPILE_TEST
>> diff --git a/drivers/soc/qcom/Makefile b/drivers/soc/qcom/Makefile
>> index 24514c7..70d5de6 100644
>> --- a/drivers/soc/qcom/Makefile
>> +++ b/drivers/soc/qcom/Makefile
>> @@ -21,6 +21,7 @@ obj-$(CONFIG_QCOM_SMP2P)	+= smp2p.o
>>   obj-$(CONFIG_QCOM_SMSM)	+= smsm.o
>>   obj-$(CONFIG_QCOM_SOCINFO)	+= socinfo.o
>>   obj-$(CONFIG_QCOM_SPM)		+= spm.o
>> +obj-$(CONFIG_QCOM_STATS)	+= qcom_stats.o
>>   obj-$(CONFIG_QCOM_WCNSS_CTRL) += wcnss_ctrl.o
>>   obj-$(CONFIG_QCOM_APR) += apr.o
>>   obj-$(CONFIG_QCOM_LLCC) += llcc-qcom.o
>> diff --git a/drivers/soc/qcom/qcom_stats.c b/drivers/soc/qcom/qcom_stats.c
>> new file mode 100644
>> index 0000000..817505b
>> --- /dev/null
>> +++ b/drivers/soc/qcom/qcom_stats.c
>> @@ -0,0 +1,277 @@
>> +// SPDX-License-Identifier: GPL-2.0-only
>> +/*
>> + * Copyright (c) 2011-2021, The Linux Foundation. All rights reserved.
>> + */
>> +
>> +#include <linux/debugfs.h>
>> +#include <linux/device.h>
>> +#include <linux/io.h>
>> +#include <linux/module.h>
>> +#include <linux/of.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/seq_file.h>
>> +
>> +#include <linux/soc/qcom/smem.h>
>> +#include <clocksource/arm_arch_timer.h>
>> +
>> +#define RPM_DYNAMIC_ADDR	0x14
>> +#define RPM_DYNAMIC_ADDR_MASK	0xFFFF
>> +
>> +#define STAT_TYPE_OFFSET	0x0
>> +#define COUNT_OFFSET		0x4
>> +#define LAST_ENTERED_AT_OFFSET	0x8
>> +#define LAST_EXITED_AT_OFFSET	0x10
>> +#define ACCUMULATED_OFFSET	0x18
>> +#define CLIENT_VOTES_OFFSET	0x1c
>> +
>> +struct subsystem_data {
>> +	const char *name;
>> +	u32 smem_item;
>> +	u32 pid;
>> +};
>> +
>> +static const struct subsystem_data subsystems[] = {
>> +	{ "modem", 605, 1 },
>> +	{ "wpss", 605, 13 },
>> +	{ "adsp", 606, 2 },
>> +	{ "cdsp", 607, 5 },
>> +	{ "slpi", 608, 3 },
>> +	{ "gpu", 609, 0 },
>> +	{ "display", 610, 0 },
>> +	{ "adsp_island", 613, 2 },
>> +	{ "slpi_island", 613, 3 },
>> +};
>> +
>> +struct stats_config {
>> +	size_t stats_offset;
>> +	size_t num_records;
>> +	bool appended_stats_avail;
>> +	bool dynamic_offset;
>> +	bool subsystem_stats_in_smem;
>> +};
>> +
>> +struct stats_data {
>> +	bool appended_stats_avail;
>> +	void __iomem *base;
>> +};
>> +
>> +struct sleep_stats {
>> +	u32 stat_type;
>> +	u32 count;
>> +	u64 last_entered_at;
>> +	u64 last_exited_at;
>> +	u64 accumulated;
>> +};
>> +
>> +struct appended_stats {
>> +	u32 client_votes;
>> +	u32 reserved[3];
>> +};
>> +
>> +static void qcom_print_stats(struct seq_file *s, const struct sleep_stats *stat)
>> +{
>> +	u64 accumulated = stat->accumulated;
>> +	/*
>> +	 * If a subsystem is in sleep when reading the sleep stats adjust
>> +	 * the accumulated sleep duration to show actual sleep time.
>> +	 */
>> +	if (stat->last_entered_at > stat->last_exited_at)
>> +		accumulated += arch_timer_read_counter() - stat->last_entered_at;
>> +
>> +	seq_printf(s, "Count: %u\n", stat->count);
>> +	seq_printf(s, "Last Entered At: %llu\n", stat->last_entered_at);
>> +	seq_printf(s, "Last Exited At: %llu\n", stat->last_exited_at);
>> +	seq_printf(s, "Accumulated Duration: %llu\n", accumulated);
>> +}
>> +
>> +static int qcom_subsystem_sleep_stats_show(struct seq_file *s, void *unused)
>> +{
>> +	struct subsystem_data *subsystem = s->private;
>> +	struct sleep_stats *stat;
>> +
>> +	/* Items are allocated lazily, so lookup pointer each time */
>> +	stat = qcom_smem_get(subsystem->pid, subsystem->smem_item, NULL);
>> +	if (IS_ERR(stat))
>> +		return -EIO;
>> +
>> +	qcom_print_stats(s, stat);
>> +
>> +	return 0;
>> +}
>> +
>> +static int qcom_soc_sleep_stats_show(struct seq_file *s, void *unused)
>> +{
>> +	struct stats_data *d = s->private;
>> +	void __iomem *reg = d->base;
>> +	struct sleep_stats stat;
>> +
>> +	memcpy_fromio(&stat, reg, sizeof(stat));
>> +	qcom_print_stats(s, &stat);
>> +
>> +	if (d->appended_stats_avail) {
>> +		struct appended_stats votes;
>> +
>> +		memcpy_fromio(&votes, reg + CLIENT_VOTES_OFFSET, sizeof(votes));
>> +		seq_printf(s, "Client Votes: %#x\n", votes.client_votes);
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>> +DEFINE_SHOW_ATTRIBUTE(qcom_soc_sleep_stats);
>> +DEFINE_SHOW_ATTRIBUTE(qcom_subsystem_sleep_stats);
>> +
>> +static void qcom_create_soc_sleep_stat_files(struct dentry *root, void __iomem *reg,
>> +					     struct stats_data *d,
>> +					     const struct stats_config *config)
>> +{
>> +	char stat_type[sizeof(u32) + 1] = {0};
>> +	size_t stats_offset = config->stats_offset;
>> +	u32 offset = 0, type;
>> +	int i, j;
>> +
>> +	/*
>> +	 * On RPM targets, stats offset location is dynamic and changes from target
>> +	 * to target and sometimes from build to build for same target.
>> +	 *
>> +	 * In such cases the dynamic address is present at 0x14 offset from base
>> +	 * address in devicetree. The last 16bits indicates the stats_offset.
>> +	 */
>> +	if (config->dynamic_offset) {
>> +		stats_offset = readl(reg + RPM_DYNAMIC_ADDR);
>> +		stats_offset &= RPM_DYNAMIC_ADDR_MASK;
>> +	}
>> +
>> +	for (i = 0; i < config->num_records; i++) {
>> +		d[i].base = reg + offset + stats_offset;
>> +
>> +		/*
>> +		 * Read the low power mode name and create debugfs file for it.
>> +		 * The names read could be of below,
>> +		 * (may change depending on low power mode supported).
>> +		 * For rpmh-sleep-stats: "aosd", "cxsd" and "ddr".
>> +		 * For rpm-sleep-stats: "vmin" and "vlow".
> 
> It reports 'vmin' and 'xosd' on MSM8939, 'vmin' and 'vlow' on SDM660.
> I know that 'vmin' is VDD Minimization mode, and 'xosd' is XO Shutdown
> mode.  But I'm not sure about 'vlow' mode.  Could you share some
> information regarding what this low power mode is, and how it differs
> from 'vmin' and 'xosd'?

vlow and xosd are same.
vmin is xosd plus voltage minimization of chip, memory rails.

Thanks,
Maulik

> 
> Also I guess XO Shutdown mode is still available on SoCs that report
> 'vlow' instead of 'xosd', just like SDM660.  Is there any way we can
> still check the stats of XO Shutdown mode on these SoCs?  Thanks!
> 
> Shawn
> 
>> +		 */
>> +		type = readl(d[i].base);
>> +		for (j = 0; j < sizeof(u32); j++) {
>> +			stat_type[j] = type & 0xff;
>> +			type = type >> 8;
>> +		}
>> +		strim(stat_type);
>> +		debugfs_create_file(stat_type, 0400, root, &d[i],
>> +				    &qcom_soc_sleep_stats_fops);
>> +
>> +		offset += sizeof(struct sleep_stats);
>> +		if (d[i].appended_stats_avail)
>> +			offset += sizeof(struct appended_stats);
>> +	}
>> +}
>> +
>> +static void qcom_create_subsystem_stat_files(struct dentry *root,
>> +					     const struct stats_config *config)
>> +{
>> +	const struct sleep_stats *stat;
>> +	int i;
>> +
>> +	if (!config->subsystem_stats_in_smem)
>> +		return;
>> +
>> +	for (i = 0; i < ARRAY_SIZE(subsystems); i++) {
>> +		stat = qcom_smem_get(subsystems[i].pid, subsystems[i].smem_item, NULL);
>> +		if (IS_ERR(stat))
>> +			continue;
>> +
>> +		debugfs_create_file(subsystems[i].name, 0400, root, (void *)&subsystems[i],
>> +				    &qcom_subsystem_sleep_stats_fops);
>> +	}
>> +}
>> +
>> +static int qcom_stats_probe(struct platform_device *pdev)
>> +{
>> +	void __iomem *reg;
>> +	struct dentry *root;
>> +	const struct stats_config *config;
>> +	struct stats_data *d;
>> +	int i;
>> +
>> +	config = device_get_match_data(&pdev->dev);
>> +	if (!config)
>> +		return -ENODEV;
>> +
>> +	reg = devm_platform_get_and_ioremap_resource(pdev, 0, NULL);
>> +	if (IS_ERR(reg))
>> +		return -ENOMEM;
>> +
>> +	d = devm_kcalloc(&pdev->dev, config->num_records,
>> +			 sizeof(*d), GFP_KERNEL);
>> +	if (!d)
>> +		return -ENOMEM;
>> +
>> +	for (i = 0; i < config->num_records; i++)
>> +		d[i].appended_stats_avail = config->appended_stats_avail;
>> +
>> +	root = debugfs_create_dir("qcom_stats", NULL);
>> +
>> +	qcom_create_subsystem_stat_files(root, config);
>> +	qcom_create_soc_sleep_stat_files(root, reg, d, config);
>> +
>> +	platform_set_drvdata(pdev, root);
>> +
>> +	return 0;
>> +}
>> +
>> +static int qcom_stats_remove(struct platform_device *pdev)
>> +{
>> +	struct dentry *root = platform_get_drvdata(pdev);
>> +
>> +	debugfs_remove_recursive(root);
>> +
>> +	return 0;
>> +}
>> +
>> +static const struct stats_config rpm_data = {
>> +	.stats_offset = 0,
>> +	.num_records = 2,
>> +	.appended_stats_avail = true,
>> +	.dynamic_offset = true,
>> +	.subsystem_stats_in_smem = false,
>> +};
>> +
>> +static const struct stats_config rpmh_data = {
>> +	.stats_offset = 0x48,
>> +	.num_records = 3,
>> +	.appended_stats_avail = false,
>> +	.dynamic_offset = false,
>> +	.subsystem_stats_in_smem = true,
>> +};
>> +
>> +static const struct of_device_id qcom_stats_table[] = {
>> +	{ .compatible = "qcom,rpm-stats", .data = &rpm_data },
>> +	{ .compatible = "qcom,rpmh-stats", .data = &rpmh_data },
>> +	{ }
>> +};
>> +MODULE_DEVICE_TABLE(of, qcom_stats_table);
>> +
>> +static struct platform_driver qcom_stats = {
>> +	.probe = qcom_stats_probe,
>> +	.remove = qcom_stats_remove,
>> +	.driver = {
>> +		.name = "qcom_stats",
>> +		.of_match_table = qcom_stats_table,
>> +	},
>> +};
>> +
>> +static int __init qcom_stats_init(void)
>> +{
>> +	return platform_driver_register(&qcom_stats);
>> +}
>> +late_initcall(qcom_stats_init);
>> +
>> +static void __exit qcom_stats_exit(void)
>> +{
>> +	platform_driver_unregister(&qcom_stats);
>> +}
>> +module_exit(qcom_stats_exit)
>> +
>> +MODULE_DESCRIPTION("Qualcomm Technologies, Inc. (QTI) Stats driver");
>> +MODULE_LICENSE("GPL v2");
>> -- 
>> QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member
>> of Code Aurora Forum, hosted by The Linux Foundation
>>

-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a 
member of Code Aurora Forum, hosted by The Linux Foundation

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