Received-SPF: pass (google.com: domain of linux-kernel+bounces-6163-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:45d1:ec00::1 as permitted sender) client-ip=2604:1380:45d1:ec00::1;
Message-ID: <56f477d9-0b7b-4671-a09c-cc3fc24a8492@quicinc.com>
Date: Wed, 20 Dec 2023 08:27:39 +0800
Precedence: bulk
MIME-Version: 1.0
User-Agent: Mozilla Thunderbird
Subject: Re: [PATCH v3 2/8] coresight-tpda: Add support to configure CMB
 element
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>, Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>
CC: Jinlong Mao <quic_jinlmao@quicinc.com>, Leo Yan <leo.yan@linaro.org>,
        "Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
        <coresight@lists.linaro.org>, <linux-arm-kernel@lists.infradead.org>,
        <linux-kernel@vger.kernel.org>, <devicetree@vger.kernel.org>,
        Tingwei Zhang
	<quic_tingweiz@quicinc.com>,
        Yuanfang Zhang <quic_yuanfang@quicinc.com>,
        Trilok Soni <quic_tsoni@quicinc.com>,
        Song Chai <quic_songchai@quicinc.com>, <linux-arm-msm@vger.kernel.org>,
        <andersson@kernel.org>
References: <1700533494-19276-1-git-send-email-quic_taozha@quicinc.com>
 <1700533494-19276-3-git-send-email-quic_taozha@quicinc.com>
 <88e51407-344e-4584-8711-29cc014c782b@arm.com>
 <b5965008-b51d-4bb7-8cf2-d21aa35d2205@quicinc.com>
 <fa39e477-7faf-46e4-8ae2-9eb2321afc26@arm.com>
From: Tao Zhang <quic_taozha@quicinc.com>
In-Reply-To: <fa39e477-7faf-46e4-8ae2-9eb2321afc26@arm.com>
Content-Type: text/plain; charset="UTF-8"; format=flowed
Content-Transfer-Encoding: 8bit


On 12/19/2023 9:54 PM, Suzuki K Poulose wrote:
> On 19/12/2023 02:13, Tao Zhang wrote:
>>
>> On 12/18/2023 6:27 PM, Suzuki K Poulose wrote:
>>> On 21/11/2023 02:24, Tao Zhang wrote:
>>>> Read the CMB element size from the device tree. Set the register
>>>> bit that controls the CMB element size of the corresponding port.
>>>>
>>>> Signed-off-by: Tao Zhang <quic_taozha@quicinc.com>
>>>> Signed-off-by: Mao Jinlong <quic_jinlmao@quicinc.com>
>>>> ---
>>>>   drivers/hwtracing/coresight/coresight-tpda.c | 117 
>>>> +++++++++++--------
>>>>   drivers/hwtracing/coresight/coresight-tpda.h |   6 +
>>>>   2 files changed, 74 insertions(+), 49 deletions(-)
>>>>
>>>> diff --git a/drivers/hwtracing/coresight/coresight-tpda.c 
>>>> b/drivers/hwtracing/coresight/coresight-tpda.c
>>>> index 5f82737c37bb..e3762f38abb3 100644
>>>> --- a/drivers/hwtracing/coresight/coresight-tpda.c
>>>> +++ b/drivers/hwtracing/coresight/coresight-tpda.c
>>>> @@ -28,24 +28,54 @@ static bool coresight_device_is_tpdm(struct 
>>>> coresight_device *csdev)
>>>>               CORESIGHT_DEV_SUBTYPE_SOURCE_TPDM);
>>>>   }
>>>>   +static void tpdm_clear_element_size(struct coresight_device *csdev)
>>>> +{
>>>> +    struct tpda_drvdata *drvdata = 
>>>> dev_get_drvdata(csdev->dev.parent);
>>>> +
>>>> +    if (drvdata->dsb_esize)
>>>> +        drvdata->dsb_esize = 0;
>>>> +    if (drvdata->cmb_esize)
>>>> +        drvdata->cmb_esize = 0;
>>>
>>> Why do we need the if (...) check here ?
>>
>> The element size of all the TPDM sub-unit should be set to 0 here.
>>
>> I will update this in the next patch series.
>>
>>>
>>>> +}
>>>> +
>>>> +static void tpda_set_element_size(struct tpda_drvdata *drvdata, 
>>>> u32 *val)
>>>> +{
>>>> +
>>>> +    if (drvdata->dsb_esize == 64)
>>>> +        *val |= TPDA_Pn_CR_DSBSIZE;
>>>> +    else if (drvdata->dsb_esize == 32)
>>>> +        *val &= ~TPDA_Pn_CR_DSBSIZE;
>>>> +
>>>> +    if (drvdata->cmb_esize == 64)
>>>> +        *val |= FIELD_PREP(TPDA_Pn_CR_CMBSIZE, 0x2);
>>>> +    else if (drvdata->cmb_esize == 32)
>>>> +        *val |= FIELD_PREP(TPDA_Pn_CR_CMBSIZE, 0x1);
>>>> +    else if (drvdata->cmb_esize == 8)
>>>> +        *val &= ~TPDA_Pn_CR_CMBSIZE;
>>>> +}
>>>> +
>>>
>>>
>>>>   /*
>>>> - * Read the DSB element size from the TPDM device
>>>> + * Read the element size from the TPDM device
>>>>    * Returns
>>>> - *    The dsb element size read from the devicetree if available.
>>>> + *    The element size read from the devicetree if available.
>>>>    *    0 - Otherwise, with a warning once.
>>>
>>> This doesn't match the function ? It return 0 on success and
>>> error (-EINVAL) on failure ?
>>
>> 0 means the element size property is found from the devicetree.
>>
>> Otherwise, it will return error(-EINVAL).
>>
>> I will update this in the next patch series.
>>
>>>
>>>>    */
>>>> -static int tpdm_read_dsb_element_size(struct coresight_device *csdev)
>>>> +static int tpdm_read_element_size(struct tpda_drvdata *drvdata,
>>>> +                  struct coresight_device *csdev)
>>>>   {
>>>> -    int rc = 0;
>>>> -    u8 size = 0;
>>>> -
>>>> -    rc = fwnode_property_read_u8(dev_fwnode(csdev->dev.parent),
>>>> -            "qcom,dsb-element-size", &size);
>>>> +    int rc = -EINVAL;
>>>> +
>>>> +    if (!fwnode_property_read_u8(dev_fwnode(csdev->dev.parent),
>>>> +            "qcom,dsb-element-size", &drvdata->dsb_esize))
>>>> +        rc = 0;
>>>> +    if (!fwnode_property_read_u8(dev_fwnode(csdev->dev.parent),
>>>> +            "qcom,cmb-element-size", &drvdata->cmb_esize))
>>>> +        rc = 0;
>>>
>>> Are we not silently resetting the error if the former failed ?
>>>
>>> Could we not :
>>>
>>>     rc |= fwnode_...
>>>
>>>     rc |= fwnode_...
>>>
>>> instead ?
>>>
>>> Also what is the expectation here ? Are these properties a MUST for
>>> TPDM ?
>>
>> The TPDM must have one of the element size property. As long as one
>
> Please add a comment in the function. Someone else might try to "fix"
> it otherwise.

Sure, I will update this in the next patch series.


Best,

Tao

>
> Suzuki
>>
>> can be found, this TPDM configuration can be considered valid. So this
>>
>> function will return 0 if one of the element size property is found.
>
>
>>
>>
>> Best,
>>
>> Tao
>>
>>>
>>>>       if (rc)
>>>>           dev_warn_once(&csdev->dev,
>>>> -            "Failed to read TPDM DSB Element size: %d\n", rc);
>>>> +            "Failed to read TPDM Element size: %d\n", rc);
>>>>   -    return size;
>>>> +    return rc;
>>>>   }
>>>>     /*
>>>> @@ -56,11 +86,12 @@ static int tpdm_read_dsb_element_size(struct 
>>>> coresight_device *csdev)
>>>>    * Parameter "inport" is used to pass in the input port number
>>>>    * of TPDA, and it is set to -1 in the recursize call.
>>>>    */
>>>> -static int tpda_get_element_size(struct coresight_device *csdev,
>>>> +static int tpda_get_element_size(struct tpda_drvdata *drvdata,
>>>> +                 struct coresight_device *csdev,
>>>>                    int inport)
>>>>   {
>>>> -    int dsb_size = -ENOENT;
>>>> -    int i, size;
>>>> +    int rc = 0;
>>>> +    int i;
>>>>       struct coresight_device *in;
>>>>         for (i = 0; i < csdev->pdata->nr_inconns; i++) {
>>>> @@ -74,25 +105,21 @@ static int tpda_get_element_size(struct 
>>>> coresight_device *csdev,
>>>>               continue;
>>>>             if (coresight_device_is_tpdm(in)) {
>>>> -            size = tpdm_read_dsb_element_size(in);
>>>> +            if ((drvdata->dsb_esize) || (drvdata->cmb_esize))
>>>> +                return -EEXIST;
>>>> +            rc = tpdm_read_element_size(drvdata, in);
>>>> +            if (rc)
>>>> +                return rc;
>>>>           } else {
>>>>               /* Recurse down the path */
>>>> -            size = tpda_get_element_size(in, -1);
>>>> -        }
>>>> -
>>>> -        if (size < 0)
>>>> -            return size;
>>>> -
>>>> -        if (dsb_size < 0) {
>>>> -            /* Found a size, save it. */
>>>> -            dsb_size = size;
>>>> -        } else {
>>>> -            /* Found duplicate TPDMs */
>>>> -            return -EEXIST;
>>>> +            rc = tpda_get_element_size(drvdata, in, -1);
>>>> +            if (rc)
>>>> +                return rc;
>>>>           }
>>>>       }
>>>>   -    return dsb_size;
>>>> +
>>>> +    return rc;
>>>>   }
>>>>     /* Settings pre enabling port control register */
>>>> @@ -109,7 +136,7 @@ static void tpda_enable_pre_port(struct 
>>>> tpda_drvdata *drvdata)
>>>>   static int tpda_enable_port(struct tpda_drvdata *drvdata, int port)
>>>>   {
>>>>       u32 val;
>>>> -    int size;
>>>> +    int rc;
>>>>         val = readl_relaxed(drvdata->base + TPDA_Pn_CR(port));
>>>>       /*
>>>> @@ -117,29 +144,21 @@ static int tpda_enable_port(struct 
>>>> tpda_drvdata *drvdata, int port)
>>>>        * Set the bit to 0 if the size is 32
>>>>        * Set the bit to 1 if the size is 64
>>>>        */
>>>> -    size = tpda_get_element_size(drvdata->csdev, port);
>>>> -    switch (size) {
>>>> -    case 32:
>>>> -        val &= ~TPDA_Pn_CR_DSBSIZE;
>>>> -        break;
>>>> -    case 64:
>>>> -        val |= TPDA_Pn_CR_DSBSIZE;
>>>> -        break;
>>>> -    case 0:
>>>> -        return -EEXIST;
>>>> -    case -EEXIST:
>>>> +    tpdm_clear_element_size(drvdata->csdev);
>>>> +    rc = tpda_get_element_size(drvdata, drvdata->csdev, port);
>>>> +    if (!rc && ((drvdata->dsb_esize) || (drvdata->cmb_esize))) {
>>>> +        tpda_set_element_size(drvdata, &val);
>>>> +        /* Enable the port */
>>>> +        val |= TPDA_Pn_CR_ENA;
>>>> +        writel_relaxed(val, drvdata->base + TPDA_Pn_CR(port));
>>>> +    } else if (rc == -EEXIST)
>>>>           dev_warn_once(&drvdata->csdev->dev,
>>>> -            "Detected multiple TPDMs on port %d", -EEXIST);
>>>> -        return -EEXIST;
>>>> -    default:
>>>> -        return -EINVAL;
>>>> -    }
>>>> -
>>>> -    /* Enable the port */
>>>> -    val |= TPDA_Pn_CR_ENA;
>>>> -    writel_relaxed(val, drvdata->base + TPDA_Pn_CR(port));
>>>> +                  "Detected multiple TPDMs on port %d", -EEXIST);
>>>> +    else
>>>> +        dev_warn_once(&drvdata->csdev->dev,
>>>> +                  "Didn't find TPDM elem size");
>>>
>>> "element size"
>>>
>>>>   -    return 0;
>>>> +    return rc;
>>>>   }
>>>>     static int __tpda_enable(struct tpda_drvdata *drvdata, int port)
>>>> diff --git a/drivers/hwtracing/coresight/coresight-tpda.h 
>>>> b/drivers/hwtracing/coresight/coresight-tpda.h
>>>> index b3b38fd41b64..29164fd9711f 100644
>>>> --- a/drivers/hwtracing/coresight/coresight-tpda.h
>>>> +++ b/drivers/hwtracing/coresight/coresight-tpda.h
>>>> @@ -10,6 +10,8 @@
>>>>   #define TPDA_Pn_CR(n)        (0x004 + (n * 4))
>>>>   /* Aggregator port enable bit */
>>>>   #define TPDA_Pn_CR_ENA        BIT(0)
>>>> +/* Aggregator port CMB data set element size bit */
>>>> +#define TPDA_Pn_CR_CMBSIZE        GENMASK(7, 6)
>>>>   /* Aggregator port DSB data set element size bit */
>>>>   #define TPDA_Pn_CR_DSBSIZE        BIT(8)
>>>>   @@ -25,6 +27,8 @@
>>>>    * @csdev:      component vitals needed by the framework.
>>>>    * @spinlock:   lock for the drvdata value.
>>>>    * @enable:     enable status of the component.
>>>> + * @dsb_esize   Record the DSB element size.
>>>> + * @cmb_esize   Record the CMB element size.
>>>>    */
>>>>   struct tpda_drvdata {
>>>>       void __iomem        *base;
>>>> @@ -32,6 +36,8 @@ struct tpda_drvdata {
>>>>       struct coresight_device    *csdev;
>>>>       spinlock_t        spinlock;
>>>>       u8            atid;
>>>> +    u8            dsb_esize;
>>>> +    u8            cmb_esize;
>>>>   };
>>>>     #endif  /* _CORESIGHT_CORESIGHT_TPDA_H */
>>>
>>> Suzuki
>>>
>>>
>