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Message-ID: <ea720e1a-c0d2-84b0-8dbc-bb5031d32208@quicinc.com>
Date:   Tue, 24 May 2022 15:00:05 +0800
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Subject: Re: [PATCH v7 02/10] Coresight: Add coresight TPDM source driver
Content-Language: en-US
To:     Suzuki K Poulose <suzuki.poulose@arm.com>,
        Mathieu Poirier <mathieu.poirier@linaro.org>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Konrad Dybcio <konradybcio@gmail.com>,
        Mike Leach <mike.leach@linaro.org>
CC:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        <coresight@lists.linaro.org>,
        <linux-arm-kernel@lists.infradead.org>,
        <linux-kernel@vger.kernel.org>,
        Tingwei Zhang <quic_tingweiz@quicinc.com>,
        Yuanfang Zhang <quic_yuanfang@quicinc.com>,
        Tao Zhang <quic_taozha@quicinc.com>,
        Trilok Soni <quic_tsoni@quicinc.com>,
        Hao Zhang <quic_hazha@quicinc.com>,
        <linux-arm-msm@vger.kernel.org>,
        Bjorn Andersson <bjorn.andersson@linaro.org>
References: <20220509133947.20987-1-quic_jinlmao@quicinc.com>
 <20220509133947.20987-3-quic_jinlmao@quicinc.com>
 <38bb1ec9-56bc-0cdf-6c46-d448a46ec886@arm.com>
From:   Jinlong Mao <quic_jinlmao@quicinc.com>
In-Reply-To: <38bb1ec9-56bc-0cdf-6c46-d448a46ec886@arm.com>
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Hi Suzuki,

Thank you for the review.

On 5/23/2022 4:57 PM, Suzuki K Poulose wrote:
> Hi
>
> On 09/05/2022 14:39, Mao Jinlong wrote:
>> Add driver to support Coresight device TPDM (Trace, Profiling and
>> Diagnostics Monitor). TPDM is a monitor to collect data from
>> different datasets. This change is to add probe/enable/disable
>> functions for tpdm source.
>>
>> Signed-off-by: Tao Zhang <quic_taozha@quicinc.com>
>> Signed-off-by: Mao Jinlong <quic_jinlmao@quicinc.com>
>> ---
>>   drivers/hwtracing/coresight/Kconfig          |  13 ++
>>   drivers/hwtracing/coresight/Makefile         |   1 +
>>   drivers/hwtracing/coresight/coresight-core.c |   5 +-
>>   drivers/hwtracing/coresight/coresight-tpdm.c | 146 +++++++++++++++++++
>>   drivers/hwtracing/coresight/coresight-tpdm.h |  26 ++++
>>   include/linux/coresight.h                    |   1 +
>>   6 files changed, 191 insertions(+), 1 deletion(-)
>>   create mode 100644 drivers/hwtracing/coresight/coresight-tpdm.c
>>   create mode 100644 drivers/hwtracing/coresight/coresight-tpdm.h
>>
>> diff --git a/drivers/hwtracing/coresight/Kconfig 
>> b/drivers/hwtracing/coresight/Kconfig
>> index 514a9b8086e3..5c506a1cd08f 100644
>> --- a/drivers/hwtracing/coresight/Kconfig
>> +++ b/drivers/hwtracing/coresight/Kconfig
>> @@ -201,4 +201,17 @@ config CORESIGHT_TRBE
>>           To compile this driver as a module, choose M here: the 
>> module will be
>>         called coresight-trbe.
>> +
>> +config CORESIGHT_TPDM
>> +    tristate "CoreSight Trace, Profiling & Diagnostics Monitor driver"
>> +    select CORESIGHT_LINKS_AND_SINKS
>> +    help
>> +      This driver provides support for configuring monitor. Monitors 
>> are
>> +      primarily responsible for data set collection and support the
>> +      ability to collect any permutation of data set types. Monitors 
>> are
>> +      also responsible for interaction with system cross triggering.
>
> I find the last statement a bit confusing. Could this be :
>
>     "Monitors are also connected to the cross triggers."
Some tpdm events can be triggered by CTI trigger out.
>
>> +
>> +      To compile this driver as a module, choose M here: the module 
>> will be
>> +      called coresight-tpdm.
>> +
>>   endif
>> diff --git a/drivers/hwtracing/coresight/Makefile 
>> b/drivers/hwtracing/coresight/Makefile
>> index 329a0c704b87..6bb9b1746bc7 100644
>> --- a/drivers/hwtracing/coresight/Makefile
>> +++ b/drivers/hwtracing/coresight/Makefile
>> @@ -25,5 +25,6 @@ obj-$(CONFIG_CORESIGHT_CPU_DEBUG) += 
>> coresight-cpu-debug.o
>>   obj-$(CONFIG_CORESIGHT_CATU) += coresight-catu.o
>>   obj-$(CONFIG_CORESIGHT_CTI) += coresight-cti.o
>>   obj-$(CONFIG_CORESIGHT_TRBE) += coresight-trbe.o
>> +obj-$(CONFIG_CORESIGHT_TPDM) += coresight-tpdm.o
>>   coresight-cti-y := coresight-cti-core.o coresight-cti-platform.o \
>>              coresight-cti-sysfs.o
>> diff --git a/drivers/hwtracing/coresight/coresight-core.c 
>> b/drivers/hwtracing/coresight/coresight-core.c
>> index 23ab16dd9b5d..75fe1781df20 100644
>> --- a/drivers/hwtracing/coresight/coresight-core.c
>> +++ b/drivers/hwtracing/coresight/coresight-core.c
>> @@ -1047,7 +1047,8 @@ static int coresight_validate_source(struct 
>> coresight_device *csdev,
>>       }
>>         if (subtype != CORESIGHT_DEV_SUBTYPE_SOURCE_PROC &&
>> -        subtype != CORESIGHT_DEV_SUBTYPE_SOURCE_SOFTWARE) {
>> +        subtype != CORESIGHT_DEV_SUBTYPE_SOURCE_SOFTWARE &&
>> +        subtype != CORESIGHT_DEV_SUBTYPE_SOURCE_DATA_ONLY) {
>>           dev_err(&csdev->dev, "wrong device subtype in %s\n", 
>> function);
>>           return -EINVAL;
>>       }
>> @@ -1116,6 +1117,7 @@ int coresight_enable(struct coresight_device 
>> *csdev)
>>           per_cpu(tracer_path, cpu) = path;
>>           break;
>>       case CORESIGHT_DEV_SUBTYPE_SOURCE_SOFTWARE:
>> +    case CORESIGHT_DEV_SUBTYPE_SOURCE_DATA_ONLY:
>>           /*
>>            * Use the hash of source's device name as ID
>>            * and map the ID to the pointer of the path.
>> @@ -1165,6 +1167,7 @@ void coresight_disable(struct coresight_device 
>> *csdev)
>>           per_cpu(tracer_path, cpu) = NULL;
>>           break;
>>       case CORESIGHT_DEV_SUBTYPE_SOURCE_SOFTWARE:
>> +    case CORESIGHT_DEV_SUBTYPE_SOURCE_DATA_ONLY:
>>           hash = hashlen_hash(hashlen_string(NULL, 
>> dev_name(&csdev->dev)));
>>           /* Find the path by the hash. */
>>           path = idr_find(&path_idr, hash);
>> diff --git a/drivers/hwtracing/coresight/coresight-tpdm.c 
>> b/drivers/hwtracing/coresight/coresight-tpdm.c
>> new file mode 100644
>> index 000000000000..6a4e2a35053d
>> --- /dev/null
>> +++ b/drivers/hwtracing/coresight/coresight-tpdm.c
>> @@ -0,0 +1,146 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/*
>> + * Copyright (c) 2022 Qualcomm Innovation Center, Inc. All rights 
>> reserved.
>> + */
>> +
>> +#include <linux/amba/bus.h>
>> +#include <linux/bitmap.h>
>> +#include <linux/coresight.h>
>> +#include <linux/coresight-pmu.h>
>> +#include <linux/device.h>
>> +#include <linux/err.h>
>> +#include <linux/fs.h>
>> +#include <linux/io.h>
>> +#include <linux/kernel.h>
>> +#include <linux/module.h>
>> +#include <linux/of.h>
>> +
>> +#include "coresight-priv.h"
>> +#include "coresight-tpdm.h"
>> +
>> +DEFINE_CORESIGHT_DEVLIST(tpdm_devs, "tpdm");
>> +
>> +/* TPDM enable operations */
>> +static int tpdm_enable(struct coresight_device *csdev,
>> +               struct perf_event *event, u32 mode)
>> +{
>> +    struct tpdm_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
>> +
>> +    mutex_lock(&drvdata->lock);
>> +    if (drvdata->enable) {
>> +        mutex_unlock(&drvdata->lock);
>> +        return -EBUSY;
>> +    }
>> +
>> +    drvdata->enable = true;
>> +    mutex_unlock(&drvdata->lock);
>> +
>> +    dev_info(drvdata->dev, "TPDM tracing enabled\n");
>> +    return 0;
>> +}
>> +
>> +/* TPDM disable operations */
>> +static void tpdm_disable(struct coresight_device *csdev,
>> +             struct perf_event *event)
>> +{
>> +    struct tpdm_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
>> +
>> +    mutex_lock(&drvdata->lock);
>> +    if (!drvdata->enable) {
>> +        mutex_unlock(&drvdata->lock);
>> +        return;
>> +    }
>> +
>> +    drvdata->enable = false;
>> +    mutex_unlock(&drvdata->lock);
>> +
>> +    dev_info(drvdata->dev, "TPDM tracing disabled\n");
>> +}
>> +
>> +static const struct coresight_ops_source tpdm_source_ops = {
>> +    .enable        = tpdm_enable,
>> +    .disable    = tpdm_disable,
>> +};
>> +
>> +static const struct coresight_ops tpdm_cs_ops = {
>> +    .source_ops    = &tpdm_source_ops,
>> +};
>> +
>> +static int tpdm_probe(struct amba_device *adev, const struct amba_id 
>> *id)
>> +{
>> +    struct device *dev = &adev->dev;
>> +    struct coresight_platform_data *pdata;
>> +    struct tpdm_drvdata *drvdata;
>> +    struct coresight_desc desc = { 0 };
>> +
>> +    pdata = coresight_get_platform_data(dev);
>> +    if (IS_ERR(pdata))
>> +        return PTR_ERR(pdata);
>> +    adev->dev.platform_data = pdata;
>> +
>> +    /* driver data*/
>> +    drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
>> +    if (!drvdata)
>> +        return -ENOMEM;
>> +    drvdata->dev = &adev->dev;
>> +    dev_set_drvdata(dev, drvdata);
>> +
>> +    drvdata->base = devm_ioremap_resource(dev, &adev->res);
>> +    if (!drvdata->base)
>> +        return -ENOMEM;
>> +
>> +    mutex_init(&drvdata->lock);
>> +
>> +    /* Set up coresight component description */
>> +    desc.name = coresight_alloc_device_name(&tpdm_devs, dev);
>> +    if (!desc.name)
>> +        return -ENOMEM;
>> +    desc.type = CORESIGHT_DEV_TYPE_SOURCE;
>> +    desc.subtype.source_subtype = 
>> CORESIGHT_DEV_SUBTYPE_SOURCE_DATA_ONLY;
>> +    desc.ops = &tpdm_cs_ops;
>> +    desc.pdata = adev->dev.platform_data;
>> +    desc.dev = &adev->dev;
>
> desc.access must be initialised here.
>
>     desc.access = CSDEV_ACCESS_IOMEM(drvdata->base);
>
>> +    drvdata->csdev = coresight_register(&desc);
>> +    if (IS_ERR(drvdata->csdev))
>> +        return PTR_ERR(drvdata->csdev);
>> +
>> +    /* Decrease pm refcount when probe is done.*/
>> +    pm_runtime_put(&adev->dev);
>> +
>> +    return 0;
>> +}
>> +
>> +static void __exit tpdm_remove(struct amba_device *adev)
>> +{
>> +    struct tpdm_drvdata *drvdata = dev_get_drvdata(&adev->dev);
>> +
>> +    coresight_unregister(drvdata->csdev);
>> +}
>> +
>> +/*
>> + * Different TPDM has different periph id.
>> + * The difference is 0-7 bits' value. So ignore 0-7 bits.
>> + */
>> +static struct amba_id tpdm_ids[] = {
>> +    {
>> +        .id = 0x000f0e00,
>> +        .mask = 0x000fff00,
>> +    },
>> +    { 0, 0},
>> +};
>> +
>> +static struct amba_driver tpdm_driver = {
>> +    .drv = {
>> +        .name   = "coresight-tpdm",
>> +        .owner    = THIS_MODULE,
>> +        .suppress_bind_attrs = true,
>> +    },
>> +    .probe          = tpdm_probe,
>> +    .id_table    = tpdm_ids,
>> +    .remove        = tpdm_remove,
>> +};
>> +
>> +module_amba_driver(tpdm_driver);
>> +
>> +MODULE_LICENSE("GPL v2");
>> +MODULE_DESCRIPTION("Trace, Profiling & Diagnostic Monitor driver");
>> diff --git a/drivers/hwtracing/coresight/coresight-tpdm.h 
>> b/drivers/hwtracing/coresight/coresight-tpdm.h
>> new file mode 100644
>> index 000000000000..94a7748a5426
>> --- /dev/null
>> +++ b/drivers/hwtracing/coresight/coresight-tpdm.h
>> @@ -0,0 +1,26 @@
>> +/* SPDX-License-Identifier: GPL-2.0 */
>> +/*
>> + * Copyright (c) 2022 Qualcomm Innovation Center, Inc. All rights 
>> reserved.
>> + */
>> +
>> +#ifndef _CORESIGHT_CORESIGHT_TPDM_H
>> +#define _CORESIGHT_CORESIGHT_TPDM_H
>> +
>> +/**
>> + * struct tpdm_drvdata - specifics associated to an TPDM component
>> + * @base:       memory mapped base address for this component.
>> + * @dev:        The device entity associated to this component.
>> + * @csdev:      component vitals needed by the framework.
>> + * @lock:       lock for the enable value.
>> + * @enable:     enable status of the component.
>> + */
>> +
>> +struct tpdm_drvdata {
>> +    void __iomem        *base;
>> +    struct device        *dev;
>> +    struct coresight_device    *csdev;
>> +    struct mutex        lock;
>
> Why mutex lock ? Couldn't this be a spinlock ?
1. There is no irq for TPDM
2. As there are 7 dataset types, there will be some FOR loop to configure
tpdm registers which may cause some time.


>
>> +    bool            enable;
>> +};
>> +
>> +#endif  /* _CORESIGHT_CORESIGHT_TPDM_H */
>> diff --git a/include/linux/coresight.h b/include/linux/coresight.h
>> index 247147c11231..a9efac55029d 100644
>> --- a/include/linux/coresight.h
>> +++ b/include/linux/coresight.h
>> @@ -61,6 +61,7 @@ enum coresight_dev_subtype_source {
>>       CORESIGHT_DEV_SUBTYPE_SOURCE_PROC,
>>       CORESIGHT_DEV_SUBTYPE_SOURCE_BUS,
>>       CORESIGHT_DEV_SUBTYPE_SOURCE_SOFTWARE,
>> +    CORESIGHT_DEV_SUBTYPE_SOURCE_DATA_ONLY,
>
> super minor nit: I find the choice of name a bit odd.
> We could simply make it something like :
>
>     CORESIGHT_DEV_SUBTYPE_SOURCE_OTHERS:
>
> Suzuki
I will check and update.
>
>>   };
>>     enum coresight_dev_subtype_helper {
>
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