Re: [PATCH v2 3/9] coresight-tpdm: Initialize DSB subunit configuration

Suzuki K Poulose
2023-02-28T11:17:01Z

On 19/01/2023 07:41, Tao Zhang wrote:
> DSB subunit need to be configured in enablement and disablement.
> A struct that specifics associated to dsb dataset is needed. It
> saves the configuration and parameters of the dsb datasets. This
> change is to add this struct and initialize the configuration of
> DSB subunit.

Please could add a line about the type of things you can do with DSB.
e.g, Timestamp, trigger type etc ? The description seems to be
describing the code, rather than the functionality of the code.

>
> Signed-off-by: Tao Zhang <quic_taozha@quicinc.com>
> Signed-off-by: Tao Zhang <taozha@qti.qualcomm.com>

As pointed out on the previous response by someone else, please fix the
above to single.

> ---
> drivers/hwtracing/coresight/coresight-tpdm.c | 57 ++++++++++++++++++++++++++--
> drivers/hwtracing/coresight/coresight-tpdm.h | 17 +++++++++
> 2 files changed, 70 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/hwtracing/coresight/coresight-tpdm.c b/drivers/hwtracing/coresight/coresight-tpdm.c
> index d85ca96..6befc87 100644
> --- a/drivers/hwtracing/coresight/coresight-tpdm.c
> +++ b/drivers/hwtracing/coresight/coresight-tpdm.c
> @@ -24,13 +24,35 @@ static void tpdm_enable_dsb(struct tpdm_drvdata *drvdata)
> {
> u32 val;
>
> + val = readl_relaxed(drvdata->base + TPDM_DSB_TIER);
> + /* Set trigger timestamp */
> + if (drvdata->dsb->trig_ts)
> + val |= TPDM_DSB_XTRIG_TSENAB;
> + else
> + val &= ~TPDM_DSB_XTRIG_TSENAB;
> + writel_relaxed(val, drvdata->base + TPDM_DSB_TIER);
> +
> + val = readl_relaxed(drvdata->base + TPDM_DSB_CR);
> + /* Set trigger type */
> + if (drvdata->dsb->trig_type)
> + val |= TPDM_DSB_TRIG_TYPE;
> + else
> + val &= ~TPDM_DSB_TRIG_TYPE;
> + writel_relaxed(val, drvdata->base + TPDM_DSB_CR);
> +
> /* Set the enable bit of DSB control register to 1 */
> val = readl_relaxed(drvdata->base + TPDM_DSB_CR);
> val |= TPDM_DSB_CR_ENA;
> writel_relaxed(val, drvdata->base + TPDM_DSB_CR);

Do they have to be written out separately ? Why not combine the value
updates to the TPDM_DSB_CR ?

> }
>
> -/* TPDM enable operations */
> +/* TPDM enable operations

Minor nit: Comment style issues.

> + * The TPDM or Monitor serves as data collection component for various
> + * dataset types. It covers Basic Counts(BC), Tenure Counts(TC),
> + * Continuous Multi-Bit(CMB), Multi-lane CMB(MCMB) and Discrete Single
> + * Bit(DSB). This function will initialize the configuration according
> + * to the dataset type supported by the TPDM.
> + */
> static void __tpdm_enable(struct tpdm_drvdata *drvdata)
> {
> CS_UNLOCK(drvdata->base);
> @@ -110,15 +132,33 @@ static const struct coresight_ops tpdm_cs_ops = {
> .source_ops = &tpdm_source_ops,
> };
>
> -static void tpdm_init_default_data(struct tpdm_drvdata *drvdata)
> +static void tpdm_datasets_setup(struct tpdm_drvdata *drvdata)
> {
> u32 pidr;
>
> - CS_UNLOCK(drvdata->base);
> /* Get the datasets present on the TPDM. */
> pidr = readl_relaxed(drvdata->base + CORESIGHT_PERIPHIDR0);
> drvdata->datasets |= pidr & GENMASK(TPDM_DATASETS - 1, 0);
> - CS_LOCK(drvdata->base);
> +}
> +
> +static int tpdm_datasets_alloc(struct tpdm_drvdata *drvdata)
> +{
> + if (drvdata->datasets & TPDM_PIDR0_DS_DSB) {
> + drvdata->dsb = devm_kzalloc(drvdata->dev, sizeof(*drvdata->dsb),
> + GFP_KERNEL);
> + if (!drvdata->dsb)
> + return -ENOMEM;
> + }
> +
> + return 0;
> +}
> +

Couldn't this be moved into the init_default_data() ?

> +static void tpdm_init_default_data(struct tpdm_drvdata *drvdata)
> +{
> + if (drvdata->datasets & TPDM_PIDR0_DS_DSB) {
> + drvdata->dsb->trig_ts = true;
> + drvdata->dsb->trig_type = false;

> + }
> }

It looks a bit silly to move the initialisation to a separate function.
Please could you fold this to tpdm_datasets_alloc() and may be even
rename that function to tpdm_init_datasets() ?

Suzuki

>
> /*
> @@ -181,6 +221,7 @@ static int tpdm_probe(struct amba_device *adev, const struct amba_id *id)
> struct coresight_platform_data *pdata;
> struct tpdm_drvdata *drvdata;
> struct coresight_desc desc = { 0 };
> + int ret;
>
> pdata = coresight_get_platform_data(dev);
> if (IS_ERR(pdata))
> @@ -200,6 +241,8 @@ static int tpdm_probe(struct amba_device *adev, const struct amba_id *id)
>
> drvdata->base = base;
>
> + tpdm_datasets_setup(drvdata);
> +
> /* Set up coresight component description */
> desc.name = coresight_alloc_device_name(&tpdm_devs, dev);
> if (!desc.name)
> @@ -216,7 +259,13 @@ static int tpdm_probe(struct amba_device *adev, const struct amba_id *id)
> return PTR_ERR(drvdata->csdev);
>
> spin_lock_init(&drvdata->spinlock);
> + ret = tpdm_datasets_alloc(drvdata);
> + if (ret) {
> + coresight_unregister(drvdata->csdev);
> + return ret;
> + }
> tpdm_init_default_data(drvdata);
> +
> /* Decrease pm refcount when probe is done.*/
> pm_runtime_put(&adev->dev);
>
> diff --git a/drivers/hwtracing/coresight/coresight-tpdm.h b/drivers/hwtracing/coresight/coresight-tpdm.h
> index 5438540..3ad1be5 100644
> --- a/drivers/hwtracing/coresight/coresight-tpdm.h
> +++ b/drivers/hwtracing/coresight/coresight-tpdm.h
> @@ -11,8 +11,14 @@
>
> /* DSB Subunit Registers */
> #define TPDM_DSB_CR (0x780)
> +#define TPDM_DSB_TIER (0x784)
> +
> /* Enable bit for DSB subunit */
> #define TPDM_DSB_CR_ENA BIT(0)
> +/* Enable bit for DSB subunit trigger timestamp */
> +#define TPDM_DSB_XTRIG_TSENAB BIT(1)
> +/* Enable bit for DSB subunit trigger type */
> +#define TPDM_DSB_TRIG_TYPE BIT(12)
>
> /* TPDM integration test registers */
> #define TPDM_ITATBCNTRL (0xEF0)
> @@ -41,6 +47,16 @@
> #define TPDM_PIDR0_DS_DSB BIT(1)
>
> /**
> + * struct dsb_dataset - specifics associated to dsb dataset
> + * @trig_ts: Enable/Disable trigger timestamp.
> + * @trig_type: Enable/Disable trigger type.
> + */
> +struct dsb_dataset {
> + bool trig_ts;
> + bool trig_type;
> +};
> +
> +/**
> * struct tpdm_drvdata - specifics associated to an TPDM component
> * @base: memory mapped base address for this component.
> * @dev: The device entity associated to this component.
> @@ -57,6 +73,7 @@ struct tpdm_drvdata {
> spinlock_t spinlock;
> bool enable;
> unsigned long datasets;
> + struct dsb_dataset *dsb;
> };
>
> #endif /* _CORESIGHT_CORESIGHT_TPDM_H */