Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <41840389-4ccb-ce0e-b798-919d09e2f0f1@linaro.org>
Date:   Tue, 18 Apr 2023 15:03:21 +0200
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101
 Thunderbird/102.9.1
Subject: Re: [PATCH v4 2/2] soc: qcom: Introduce RPM master stats driver
Content-Language: en-US
To:     Manivannan Sadhasivam <mani@kernel.org>
Cc:     Andy Gross <agross@kernel.org>,
        Bjorn Andersson <andersson@kernel.org>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Marijn Suijten <marijn.suijten@somainline.org>,
        linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org
References: <20230405-topic-master_stats-v4-0-4217362fcc79@linaro.org>
 <20230405-topic-master_stats-v4-2-4217362fcc79@linaro.org>
 <20230418125047.GB5530@thinkpad>
From:   Konrad Dybcio <konrad.dybcio@linaro.org>
In-Reply-To: <20230418125047.GB5530@thinkpad>
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 7bit
Precedence: bulk


On 18.04.2023 14:50, Manivannan Sadhasivam wrote:
> On Mon, Apr 17, 2023 at 07:37:53PM +0200, Konrad Dybcio wrote:
>> Introduce a driver to query and expose detailed, per-subsystem (as opposed
>> to the existing qcom_stats driver which exposes SoC-wide data) about low
>> power mode states of a given RPM master. That includes the APSS (ARM),
>> MPSS (modem) and other remote cores, depending on the platform
>> configuration.
>>
>> This is a vastly cleaned up and restructured version of a similar
>> driver found in msm-5.4.
>>
>> Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
>> ---
>>  drivers/soc/qcom/Kconfig            |  11 +++
>>  drivers/soc/qcom/Makefile           |   1 +
>>  drivers/soc/qcom/rpm_master_stats.c | 162 ++++++++++++++++++++++++++++++++++++
>>  3 files changed, 174 insertions(+)
>>
>> diff --git a/drivers/soc/qcom/Kconfig b/drivers/soc/qcom/Kconfig
>> index a491718f8064..e597799e8121 100644
>> --- a/drivers/soc/qcom/Kconfig
>> +++ b/drivers/soc/qcom/Kconfig
>> @@ -135,6 +135,17 @@ config QCOM_RMTFS_MEM
>>  
>>  	  Say y here if you intend to boot the modem remoteproc.
>>  
>> +config QCOM_RPM_MASTER_STATS
>> +	tristate "Qualcomm RPM Master stats"
>> +	depends on ARCH_QCOM || COMPILE_TEST
>> +	help
>> +	  The RPM Master sleep stats driver provides detailed per-subsystem
>> +	  sleep/wake data, read from the RPM message RAM. It can be used to
>> +	  assess whether all the low-power modes available are entered as
>> +	  expected or to check which part of the SoC prevents it from sleeping.
>> +
>> +	  Say y here if you intend to debug or monitor platform sleep.
>> +
>>  config QCOM_RPMH
>>  	tristate "Qualcomm RPM-Hardened (RPMH) Communication"
>>  	depends on ARCH_QCOM || COMPILE_TEST
>> diff --git a/drivers/soc/qcom/Makefile b/drivers/soc/qcom/Makefile
>> index 0f43a88b4894..7349371fdea1 100644
>> --- a/drivers/soc/qcom/Makefile
>> +++ b/drivers/soc/qcom/Makefile
>> @@ -14,6 +14,7 @@ obj-$(CONFIG_QCOM_QMI_HELPERS)	+= qmi_helpers.o
>>  qmi_helpers-y	+= qmi_encdec.o qmi_interface.o
>>  obj-$(CONFIG_QCOM_RAMP_CTRL)	+= ramp_controller.o
>>  obj-$(CONFIG_QCOM_RMTFS_MEM)	+= rmtfs_mem.o
>> +obj-$(CONFIG_QCOM_RPM_MASTER_STATS)	+= rpm_master_stats.o
>>  obj-$(CONFIG_QCOM_RPMH)		+= qcom_rpmh.o
>>  qcom_rpmh-y			+= rpmh-rsc.o
>>  qcom_rpmh-y			+= rpmh.o
>> diff --git a/drivers/soc/qcom/rpm_master_stats.c b/drivers/soc/qcom/rpm_master_stats.c
>> new file mode 100644
>> index 000000000000..ac87401e2217
>> --- /dev/null
>> +++ b/drivers/soc/qcom/rpm_master_stats.c
>> @@ -0,0 +1,162 @@
>> +// SPDX-License-Identifier: GPL-2.0-only
>> +/*
>> + * Copyright (c) 2012-2020, The Linux Foundation. All rights reserved.
>> + * Copyright (c) 2023, Linaro Limited
>> + *
>> + * This driver supports what is known as "Master Stats v2" in Qualcomm
>> + * downstream kernel terms, which seems to be the only version which has
>> + * ever shipped, all the way from 2013 to 2023.
>> + */
>> +
>> +#include <linux/debugfs.h>
>> +#include <linux/io.h>
>> +#include <linux/module.h>
>> +#include <linux/of.h>
>> +#include <linux/of_address.h>
>> +#include <linux/platform_device.h>
>> +
>> +struct master_stats_data {
>> +	void __iomem *base;
>> +	const char *label;
>> +};
>> +
>> +struct rpm_master_stats {
>> +	uint32_t active_cores;
>> +	uint32_t num_shutdowns;
>> +	uint64_t shutdown_req;
>> +	uint64_t wakeup_idx;
>> +	uint64_t bringup_req;
>> +	uint64_t bringup_ack;
>> +	uint32_t wakeup_reason; /* 0 = "rude wakeup", 1 = scheduled wakeup */
>> +	uint32_t last_sleep_trans_dur;
>> +	uint32_t last_wake_trans_dur;
>> +
>> +	/* Per-subsystem (*not necessarily* SoC-wide) XO shutdown stats */
>> +	uint32_t xo_count;
>> +	uint64_t xo_last_enter;
>> +	uint64_t last_exit;
>> +	uint64_t xo_total_dur;
> 
> Still no u64, u32.
Right, missed that part..

> 
>> +} __packed;
>> +
> 
> [...]
> 
>> +		/*
>> +		 * Generally it's not advised to fail on debugfs errors, but this
>> +		 * driver's only job is exposing data therein.
>> +		 */
>> +		dent = debugfs_create_file(data[i].label, 0444, root,
>> +					   &data[i], &master_stats_fops);
>> +		if (IS_ERR(dent)) {
>> +			debugfs_remove_recursive(root);
>> +			return -EINVAL;
> 
> PTR_ERR(dent). Also it doesn't hurt to use dev_err_probe() here.
Totally makes sense.

> 
>> +		}
>> +	}
>> +
>> +	device_set_pm_not_required(dev);
>> +
>> +	return 0;
>> +}
>> +
>> +static void master_stats_remove(struct platform_device *pdev)
>> +{
>> +	struct dentry *root = platform_get_drvdata(pdev);
>> +
>> +	debugfs_remove_recursive(root);
>> +}
>> +
>> +static const struct of_device_id rpm_master_table[] = {
>> +	{ .compatible = "qcom,rpm-master-stats" },
>> +	{ },
>> +};
>> +
>> +static struct platform_driver master_stats_driver = {
>> +	.probe = master_stats_probe,
>> +	.remove_new = master_stats_remove,
>> +	.driver = {
>> +		.name = "rpm_master_stats",
> 
> qcom_rpm_master_stats
> 
Fixed it everywhere else except here, will do!

Konrad
> - Mani
> 
>> +		.of_match_table = rpm_master_table,
>> +	},
>> +};
>> +module_platform_driver(master_stats_driver);
>> +
>> +MODULE_DESCRIPTION("Qualcomm RPM Master Statistics driver");
>> +MODULE_LICENSE("GPL");
>>
>> -- 
>> 2.40.0
>>
>