Re: [PATCH 2/9] coresight-tpda: Add DSB dataset support

[Tao Zhang]

Hi Suzuki,


Thanks a lot for your code review.

I will update the patch with your suggestions in the next release.

On 9/15/2022 6:14 PM, Suzuki K Poulose wrote:
> Hi Tao
>
> On 08/09/2022 09:44, 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@xxxxxxxxxxx>
> > ---
> >   drivers/hwtracing/coresight/coresight-tpda.c | 62 
> > ++++++++++++++++++++++++++++
> >   drivers/hwtracing/coresight/coresight-tpda.h |  4 ++
> >   2 files changed, 66 insertions(+)
> >
> > diff --git a/drivers/hwtracing/coresight/coresight-tpda.c 
> > b/drivers/hwtracing/coresight/coresight-tpda.c
> > index c8bbc75..76636a1 100644
> > --- a/drivers/hwtracing/coresight/coresight-tpda.c
> > +++ b/drivers/hwtracing/coresight/coresight-tpda.c
> > @@ -37,6 +37,15 @@ static void 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;
> >       /* Enable the port */
> >       val |= TPDA_Pn_CR_ENA;
> >       writel_relaxed(val, drvdata->base + TPDA_Pn_CR(port));
> > @@ -105,6 +114,55 @@ static const struct coresight_ops tpda_cs_ops = {
> >       .link_ops    = &tpda_link_ops,
> >   };
> >   +static int tpda_parse_dsb(struct tpda_drvdata *drvdata)
> > +{
> > +    int len, port, i;
> > +    const __be32 *prop;
> > +    struct device_node *node = drvdata->dev->of_node;
> > +
> > +    /* Read the size of DSB element */
> > +    prop = of_get_property(node, "qcom,dsb-elem-size", &len);
> > +    if (prop) {
> > +        len /= sizeof(__be32);
> > +        /*
> > +         * The read set of data is port and size, so the number of data
> > +         * is a multiple of two. And the number of data will not exceed
> > +         * two times that of the TPDA inpurts number.
> > +         */
> > +        if (len < 2 || len >= (2 * TPDA_MAX_INPORTS) || len % 2 != 0) {
> > +            dev_err(drvdata->dev,
> > +                "Dataset DSB width entries are wrong\n");
> > +            return -EINVAL;
> > +        }
> > +
> > +        for (i = 0; i < len; i++) {
>
> Please could we be explicit here that we are dealing with 2 entries
> in an iteration. i.e,
>
>         for (i = 0; i < len; i += 2) {
> > +            port = be32_to_cpu(prop[i++]);
>
>             port = be32_to_cpu(prop[i]);
>
> > +            if (port >= TPDA_MAX_INPORTS) {
> > +                dev_err(drvdata->dev,
> > +                    "Wrong port specified for DSB\n");
> > +                return -EINVAL;
> > +            }
> > +            /* Set DSB element size for corresponding port to 
> > dsb_esize*/
> > +            drvdata->dsb_esize[port] = be32_to_cpu(prop[i]);
>
>         drvdata->dsb_esize[port] = be32_to_cpu(prop[i + 1]);
Sure, I will update this part of the code in the next release.
> > +        }
> > +    }
> > +
> > +    return 0;
> > +}
> > +
> > +static int tpda_parse_of_data(struct tpda_drvdata *drvdata)
> > +{
> > +    int ret;
> > +
> > +    ret = tpda_parse_dsb(drvdata);
> > +    if (ret) {
> > +        dev_err(drvdata->dev, "Fail to get DSB data set element 
> > size\n");
> > +        return -EINVAL;
> > +    }
> > +
> > +    return 0;
> > +}
> > +
> >   static int tpda_init_default_data(struct tpda_drvdata *drvdata)
> >   {
> >       int atid;
> > @@ -148,6 +206,10 @@ static int tpda_probe(struct amba_device *adev, 
> > const struct amba_id *id)
> >         spin_lock_init(&drvdata->spinlock);
> >   +    ret = tpda_parse_of_data(drvdata);
> > +    if (ret)
> > +        return ret;
> > +
> >       ret = tpda_init_default_data(drvdata);
> >       if (ret)
> >           return ret;
> > diff --git a/drivers/hwtracing/coresight/coresight-tpda.h 
> > b/drivers/hwtracing/coresight/coresight-tpda.h
> > index 4beb332..ecc7869 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
>
> super minor nit: Missing ":", consistent with the other fields.
I will update in the next release.
> >    */
> >   struct tpda_drvdata {
> >       void __iomem        *base;
> > @@ -30,6 +33,7 @@ struct tpda_drvdata {
> >       struct coresight_device    *csdev;
> >       spinlock_t        spinlock;
> >       u8            atid;
> > +    u32            dsb_esize[TPDA_MAX_INPORTS];
> >   };
> >     #endif  /* _CORESIGHT_CORESIGHT_TPDA_H */
>
> Suzuki

Regards,

Tao