Re: [PATCH v10 4/8] coresight: etr: refactor the tmc_etr_get_catu_device function

[Jie Gan <jie.gan@oss.qualcomm.com>]

On 1/27/2026 12:10 AM, Suzuki K Poulose wrote:
> On 22/01/2026 02:08, Jie Gan wrote:
>> Refactor tmc_etr_get_catu_device to retrieve the helper device connected
>> to the TMC ETR based on helper_subtype.
> 
> Please could you leave this as it is and add :
> 
> tmc_etr_get_ctcu_device() ?
> 
> It doesn't make much sense to refactor something that is a wrapper for
> a generic function. Please avoid un-necessary abstraction

Well noted. Will fix it in the next version.

Thanks,
Jie

> 
> Suzuki
> 
> 
>>
>> Signed-off-by: Jie Gan <jie.gan@oss.qualcomm.com>
>> ---
>>   drivers/hwtracing/coresight/coresight-catu.c    |  3 ++-
>>   drivers/hwtracing/coresight/coresight-tmc-etr.c | 32 +++++++++++++++ 
>> +---------
>>   drivers/hwtracing/coresight/coresight-tmc.h     |  3 ++-
>>   3 files changed, 25 insertions(+), 13 deletions(-)
>>
>> diff --git a/drivers/hwtracing/coresight/coresight-catu.c b/drivers/ 
>> hwtracing/coresight/coresight-catu.c
>> index 69b36bae97ab..d3972619cc96 100644
>> --- a/drivers/hwtracing/coresight/coresight-catu.c
>> +++ b/drivers/hwtracing/coresight/coresight-catu.c
>> @@ -334,7 +334,8 @@ static int catu_alloc_etr_buf(struct tmc_drvdata 
>> *tmc_drvdata,
>>       struct tmc_sg_table *catu_table;
>>       struct catu_etr_buf *catu_buf;
>> -    csdev = tmc_etr_get_catu_device(tmc_drvdata);
>> +    csdev = tmc_etr_get_helper_device(tmc_drvdata,
>> +            CORESIGHT_DEV_SUBTYPE_HELPER_CATU);
>>       if (!csdev)
>>           return -ENODEV;
>>       catu_buf = kzalloc(sizeof(*catu_buf), GFP_KERNEL);
>> diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/ 
>> drivers/hwtracing/coresight/coresight-tmc-etr.c
>> index cbbb15648fb7..16a4562533d5 100644
>> --- a/drivers/hwtracing/coresight/coresight-tmc-etr.c
>> +++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c
>> @@ -844,28 +844,37 @@ static const struct etr_buf_operations 
>> etr_sg_buf_ops = {
>>   };
>>   /*
>> - * TMC ETR could be connected to a CATU device, which can provide 
>> address
>> - * translation service. This is represented by the Output port of the 
>> TMC
>> - * (ETR) connected to the input port of the CATU.
>> + * TMC ETR could be connected to the helper device, which can provide 
>> address
>> + * translation service(CATU) or data filter function(CTCU). This is 
>> represented
>> + * by the Output port of the TMC (ETR) connected to the input port of 
>> the helper.
>>    *
>> - * Returns    : coresight_device ptr for the CATU device if a CATU is 
>> found.
>> + * @drvdata    : drvdata of the TMC device
>> + * @subtype    : helper_subtype of the helper device
>> + *
>> + * Returns    : coresight_device ptr for the helper device if a 
>> helper is found.
>>    *        : NULL otherwise.
>>    */
>>   struct coresight_device *
>> -tmc_etr_get_catu_device(struct tmc_drvdata *drvdata)
>> +tmc_etr_get_helper_device(struct tmc_drvdata *drvdata,
>> +              enum coresight_dev_subtype_helper subtype)
>>   {
>>       struct coresight_device *etr = drvdata->csdev;
>> -    union coresight_dev_subtype catu_subtype = {
>> -        .helper_subtype = CORESIGHT_DEV_SUBTYPE_HELPER_CATU
>> +    union coresight_dev_subtype helper_subtype = {
>> +        .helper_subtype = subtype
>>       };
>> -    if (!IS_ENABLED(CONFIG_CORESIGHT_CATU))
>> +
>> +    if (subtype == CORESIGHT_DEV_SUBTYPE_HELPER_CATU &&
>> +        !IS_ENABLED(CONFIG_CORESIGHT_CATU))
>> +        return NULL;
>> +    else if (subtype == CORESIGHT_DEV_SUBTYPE_HELPER_CTCU &&
>> +         !IS_ENABLED(CONFIG_CORESIGHT_CTCU))
>>           return NULL;
>>       return coresight_find_output_type(etr->pdata, 
>> CORESIGHT_DEV_TYPE_HELPER,
>> -                      catu_subtype);
>> +                      helper_subtype);
>>   }
>> -EXPORT_SYMBOL_GPL(tmc_etr_get_catu_device);
>> +EXPORT_SYMBOL_GPL(tmc_etr_get_helper_device);
>>   static const struct etr_buf_operations *etr_buf_ops[] = {
>>       [ETR_MODE_FLAT] = &etr_flat_buf_ops,
>> @@ -913,7 +922,8 @@ static void get_etr_buf_hw(struct device *dev, 
>> struct etr_buf_hw *buf_hw)
>>       buf_hw->has_iommu = iommu_get_domain_for_dev(dev->parent);
>>       buf_hw->has_etr_sg = tmc_etr_has_cap(drvdata, TMC_ETR_SG);
>> -    buf_hw->has_catu = !!tmc_etr_get_catu_device(drvdata);
>> +    buf_hw->has_catu = !!tmc_etr_get_helper_device(drvdata,
>> +            CORESIGHT_DEV_SUBTYPE_HELPER_CATU);
>>       buf_hw->has_resrv = tmc_has_reserved_buffer(drvdata);
>>   }
>> diff --git a/drivers/hwtracing/coresight/coresight-tmc.h b/drivers/ 
>> hwtracing/coresight/coresight-tmc.h
>> index c9a82ff6cd00..7690a70069da 100644
>> --- a/drivers/hwtracing/coresight/coresight-tmc.h
>> +++ b/drivers/hwtracing/coresight/coresight-tmc.h
>> @@ -471,7 +471,8 @@ static inline uint32_t 
>> find_crash_tracedata_crc(struct tmc_drvdata *drvdata,
>>       return crc32_le(0, (void *)drvdata->resrv_buf.vaddr, crc_size);
>>   }
>> -struct coresight_device *tmc_etr_get_catu_device(struct tmc_drvdata 
>> *drvdata);
>> +struct coresight_device *tmc_etr_get_helper_device(struct tmc_drvdata 
>> *drvdata,
>> +                           enum coresight_dev_subtype_helper subtype);
>>   void tmc_etr_set_catu_ops(const struct etr_buf_operations *catu);
>>   void tmc_etr_remove_catu_ops(void);
>>
>