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: <91c8470e-0f74-d964-37ee-b18ab689cba8@quicinc.com>
Date:   Wed, 9 Aug 2023 14:14:24 +0800
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101
 Thunderbird/102.14.0
Subject: Re: [PATCH v7 04/13] coresight-tpda: Add DSB dataset support
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>,
        Hao Zhang <quic_hazha@quicinc.com>,
        <linux-arm-msm@vger.kernel.org>, <andersson@kernel.org>
References: <1690269353-10829-1-git-send-email-quic_taozha@quicinc.com>
 <1690269353-10829-5-git-send-email-quic_taozha@quicinc.com>
 <94b9ae0f-b6ed-1d72-f86a-d33842527681@arm.com>
 <43d94873-53be-d142-9075-a781b9de9f69@arm.com>
From:   Tao Zhang <quic_taozha@quicinc.com>
In-Reply-To: <43d94873-53be-d142-9075-a781b9de9f69@arm.com>
Content-Type: text/plain; charset="UTF-8"; format=flowed
Content-Transfer-Encoding: 8bit
Precedence: bulk


On 8/7/2023 5:12 PM, Suzuki K Poulose wrote:
> On 04/08/2023 16:02, Suzuki K Poulose wrote:
>> On 25/07/2023 08:15, Tao Zhang wrote:
>>> Read the DSB element size from the device tree. Set the register
>>> bit that controls the DSB element size of the corresponding port.
>>>
>>> Signed-off-by: Tao Zhang <quic_taozha@quicinc.com>
>>> ---
>>>   drivers/hwtracing/coresight/coresight-tpda.c | 96 
>>> +++++++++++++++++++++++++---
>>>   drivers/hwtracing/coresight/coresight-tpda.h |  4 ++
>>>   2 files changed, 90 insertions(+), 10 deletions(-)
>>>
>>> diff --git a/drivers/hwtracing/coresight/coresight-tpda.c 
>>> b/drivers/hwtracing/coresight/coresight-tpda.c
>>> index 8d2b9d2..7c71342 100644
>>> --- a/drivers/hwtracing/coresight/coresight-tpda.c
>>> +++ b/drivers/hwtracing/coresight/coresight-tpda.c
>>> @@ -21,6 +21,58 @@
>>>   DEFINE_CORESIGHT_DEVLIST(tpda_devs, "tpda");
>>> +/* Search and read element data size from the TPDM node in
>>
>> minor nit:
>>
>> /*
>>   * Search ...
>>
>>> + * the devicetree. Each input port of TPDA is connected to
>>> + * a TPDM. Different TPDM supports different types of dataset,
>>> + * and some may support more than one type of dataset.
>>> + * Parameter "inport" is used to pass in the input port number
>>> + * of TPDA, and it is set to 0 in the recursize call.
>>
>>> + * Parameter "parent" is used to pass in the original call.
>>
>> Please remove references to the past and describe "match_inport"
>>
>>> + */
>>> +static int tpda_set_element_size(struct tpda_drvdata *drvdata,
>>> +               struct coresight_device *csdev, int inport, bool 
>>> match_inport)
>>
>> May be we could switch the order of the parameters:
>>
>> match_inport, int port
>>
>> Or even inport < 0, implies, port wont be matched.
>>
>> i.e.,
>>
>> tpda_set_element_size(drvdata, child, inport)
>>
>>> +{
>>> +    static int nr_inport;
>>> +    int i;
>>> +    static bool tpdm_found;
>>> +    struct coresight_device *in_csdev;
>>> +
>>> +    if (inport > (TPDA_MAX_INPORTS - 1))
>>> +        return -EINVAL;
>>> +
>>> +    if (match_inport) {
>>> +        nr_inport = inport;
>>> +        tpdm_found = false;
>>> +    }
>>
>> Could we not avoid the static variables and this dance by making the 
>> function return the dsb_size ? See further down.
>>
>>
>>> +
>>> +    for (i = 0; i < csdev->pdata->nr_inconns; i++) {
>>> +        in_csdev = csdev->pdata->in_conns[i]->src_dev;
>>> +        if (!in_csdev)
>>> +            break;
>>          continue ?
>>> +
>>> +        if (match_inport)
>>> +            if (csdev->pdata->in_conns[i]->dest_port != inport)
>>> +                continue;
>>> +
>>> +        if ((in_csdev->type == CORESIGHT_DEV_TYPE_SOURCE) &&
>>> +                (in_csdev->subtype.source_subtype
>>> +                == CORESIGHT_DEV_SUBTYPE_SOURCE_TPDM)) {
>>
>> Please provide a helper :
>>
>> static bool coresight_device_is_tpdm(csdev) {
>>      return
>>       (csdev->type == CORESIGHT_DEV_TYPE_SOURCE) &&
>>       (in_csdev->subtype.source_subtype ==
>>          CORESIGHT_DEV_SUBTYPE_SOURCE_TPDM);
>> }
>>
>>
>>
>>> + of_property_read_u8(in_csdev->dev.parent->of_node,
>>> +                    "qcom,dsb-element-size", 
>>> &drvdata->dsb_esize[nr_inport]);
>>
>>
>>
>>> +            if (!tpdm_found)
>>> +                tpdm_found = true;
>>> +            else
>>> +                dev_warn(drvdata->dev,
>>> +                    "More than one TPDM is mapped to the TPDA input 
>>> port %d.\n",
>>> +                    nr_inport);
>>> +            continue;
>>> +        }
>>> +        tpda_set_element_size(drvdata, in_csdev, 0, false);
>>> +    }
>>> +
>>
>> /*
>>   * Read the DSB element size from the TPDM device
>>   * Returns
>>   *    the size read from the firmware if available.
>>   *    0 - Otherwise, with a Warning once.
>>   */
>> static int tpdm_read_dsb_element_size(struct coresight_device *csdev)
>> {
>>      int rc, size = 0;
>>
>>      rc = fwnode_property_read_u8(dev_fwnode(csdev->dev.parent),
>>                       "qcom,dsb-element-size", &size);
>>      if (rc)
>>          dev_warn_once(&in->dev, "Failed to read TPDM DSB Element 
>> size: %d\n",
>>          rc);
>>      return size;
>> }
>>
>> static int tpda_get_element_size(struct coresight_device *csdev,
>>                   int inport)
>> {
>>      int dsb_size = -ENOENT;
>>
>>      for (i = 0; i < csdev->pdata->nr_inconns; i++) {
>>          in = csdev->pdata->in_conns[i]->src_dev;
>>          if (!in)
>>              continue;
>>          if (coresight_device_is_tpdm(in)) {
>>              /* Ignore the TPDMs that do not match port */
>>              if (inport > 0 &&
>>                  (csdev->pdata->in_conns[i]->dest_port !=
>>                  inport))
>>                  continue;
>>              size = tpdm_read_dsb_element_size(csdev);
>>          } else {
>>              /* Recurse down the path */
>>              size = tpda_set_element_size(in, -1);
>>          }
>>
>>          if (size < 0)
>>              return size;
>>          /* We have found a size, save it. */
>>          if (dsb_size < 0) {
>>              dsb_size = size;
>>          } else {
>>              /* We have duplicate TPDMs */
>>              return -EEXIST;
>>          }
>>      }
>>      return dsb_size;
>> }
>>
>>
>>
>>
>>> +    return 0;
>>> +}
>>> +
>>>   /* Settings pre enabling port control register */
>>>   static void tpda_enable_pre_port(struct tpda_drvdata *drvdata)
>>>   {
>>> @@ -32,26 +84,43 @@ static void tpda_enable_pre_port(struct 
>>> tpda_drvdata *drvdata)
>>>       writel_relaxed(val, drvdata->base + TPDA_CR);
>>>   }
>>> -static void tpda_enable_port(struct tpda_drvdata *drvdata, int port)
>>> +static int tpda_enable_port(struct tpda_drvdata *drvdata, int port)
>>>   {
>>>       u32 val;
>>>       val = readl_relaxed(drvdata->base + TPDA_Pn_CR(port));
>>> +    /*
>>> +     * Configure aggregator port n DSB data set element size
>>> +     * Set the bit to 0 if the size is 32
>>> +     * Set the bit to 1 if the size is 64
>>> +     */
>>> +    if (drvdata->dsb_esize[port] == 32)
>>> +        val &= ~TPDA_Pn_CR_DSBSIZE;
>>> +    else if (drvdata->dsb_esize[port] == 64)
>>> +        val |= TPDA_Pn_CR_DSBSIZE;
>>
>> Couldn't this be detected via tpda_get_element_size()? see below.
>>
>>> +    else
>>> +        return -EINVAL;
>>> +
>>>       /* Enable the port */
>>>       val |= TPDA_Pn_CR_ENA;
>>>       writel_relaxed(val, drvdata->base + TPDA_Pn_CR(port));
>>> +
>>> +    return 0;
>>>   }
>>> -static void __tpda_enable(struct tpda_drvdata *drvdata, int port)
>>> +static int __tpda_enable(struct tpda_drvdata *drvdata, int port)
>>>   {
>>> +    int ret;
>>> +
>>>       CS_UNLOCK(drvdata->base);
>>>       if (!drvdata->csdev->enable)
>>>           tpda_enable_pre_port(drvdata);
>>> -    tpda_enable_port(drvdata, port);
>>> -
>>> +    ret = tpda_enable_port(drvdata, port);
>>>       CS_LOCK(drvdata->base);
>>> +
>>> +    return ret;
>>>   }
>>>   static int tpda_enable(struct coresight_device *csdev,
>>> @@ -59,16 +128,23 @@ static int tpda_enable(struct coresight_device 
>>> *csdev,
>>>                  struct coresight_connection *out)
>>>   {
>>>       struct tpda_drvdata *drvdata = 
>>> dev_get_drvdata(csdev->dev.parent);
>>> +    int ret;
>>> +
>>> +    ret = tpda_set_element_size(drvdata, csdev, in->dest_port, true);
>>
>>      size  = tpda_get_element_size(csdev, in->dest_port);
>>      switch (size) {
>>      case 32:
>>      case 64:
>>          break;
>
> We also need :
>
>     case 0:
>         return -ENOENT;

I will update this in the next patch series.


Best,

Tao

>
> Suzuki
>
>
>>      case -EEXIST:
>>          dev_warn_once("Detected multiple TPDMs on port %d", ..)
>>          fallthrough;
>>      default:
>>          return size;
>>      }
>>
>>      drvdata->dsb_esize[in->dest_port] = size;
>>
>> Suzuki
>>
>>
>>
>>> +    if (ret)
>>> +        return ret;
>>>       spin_lock(&drvdata->spinlock);
>>> -    if (atomic_read(&in->dest_refcnt) == 0)
>>> -        __tpda_enable(drvdata, in->dest_port);
>>> +    if (atomic_read(&in->dest_refcnt) == 0) {
>>> +        ret = __tpda_enable(drvdata, in->dest_port);
>>> +        if (!ret) {
>>> +            atomic_inc(&in->dest_refcnt);
>>> +            dev_dbg(drvdata->dev, "TPDA inport %d enabled.\n", 
>>> in->dest_port);
>>> +        }
>>> +    }
>>> -    atomic_inc(&in->dest_refcnt);
>>>       spin_unlock(&drvdata->spinlock);
>>> -
>>> -    dev_dbg(drvdata->dev, "TPDA inport %d enabled.\n", in->dest_port);
>>> -    return 0;
>>> +    return ret;
>>>   }
>>>   static void __tpda_disable(struct tpda_drvdata *drvdata, int port)
>>> diff --git a/drivers/hwtracing/coresight/coresight-tpda.h 
>>> b/drivers/hwtracing/coresight/coresight-tpda.h
>>> index 0399678..12a1472 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 DSB data set element size bit */
>>> +#define TPDA_Pn_CR_DSBSIZE        BIT(8)
>>>   #define TPDA_MAX_INPORTS    32
>>> @@ -23,6 +25,7 @@
>>>    * @csdev:      component vitals needed by the framework.
>>>    * @spinlock:   lock for the drvdata value.
>>>    * @enable:     enable status of the component.
>>> + * @dsb_esize:  DSB element size for each inport, it must be 32 or 64.
>>>    */
>>>   struct tpda_drvdata {
>>>       void __iomem        *base;
>>> @@ -30,6 +33,7 @@ struct tpda_drvdata {
>>>       struct coresight_device    *csdev;
>>>       spinlock_t        spinlock;
>>>       u8            atid;
>>> +    u8            dsb_esize[TPDA_MAX_INPORTS];
>>>   };
>>>   #endif  /* _CORESIGHT_CORESIGHT_TPDA_H */
>>
>