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

[Jie Gan]

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@xxxxxxxxxxxxxxxx>
> > ---
> >   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);