Re: [PATCH v3 8/8] coresight-tpdm: Add msr register support for CMB

[Suzuki K Poulose <suzuki.poulose@arm.com>]

On 21/11/2023 02:24, Tao Zhang wrote:
> Add the nodes for CMB subunit MSR(mux select register) support.
> CMB MSRs(mux select registers) is to separate mux,arbitration,
> ,interleaving,data packing control from stream filtering control.
> 
> Reviewed-by: James Clark <james.clark@arm.com>
> Signed-off-by: Tao Zhang <quic_taozha@quicinc.com>
> Signed-off-by: Mao Jinlong <quic_jinlmao@quicinc.com>
> ---
>   .../testing/sysfs-bus-coresight-devices-tpdm  |  8 ++
>   drivers/hwtracing/coresight/coresight-tpdm.c  | 86 +++++++++++++++++++
>   drivers/hwtracing/coresight/coresight-tpdm.h  | 16 +++-
>   3 files changed, 109 insertions(+), 1 deletion(-)
> 
> diff --git a/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm b/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm
> index e0b77107be13..914f3fd81525 100644
> --- a/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm
> +++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm
> @@ -249,3 +249,11 @@ Description:
>   		Accepts only one of the 2 values -  0 or 1.
>   		0 : Disable the timestamp of all trace packets.
>   		1 : Enable the timestamp of all trace packets.
> +
> +What:		/sys/bus/coresight/devices/<tpdm-name>/cmb_msr/msr[0:31]
> +Date:		September 2023
> +KernelVersion	6.7
> +Contact:	Jinlong Mao (QUIC) <quic_jinlmao@quicinc.com>, Tao Zhang (QUIC) <quic_taozha@quicinc.com>
> +Description:
> +		(RW) Set/Get the MSR(mux select register) for the CMB subunit
> +		TPDM.
> diff --git a/drivers/hwtracing/coresight/coresight-tpdm.c b/drivers/hwtracing/coresight/coresight-tpdm.c
> index f6cda5616e84..7e331ea436cc 100644
> --- a/drivers/hwtracing/coresight/coresight-tpdm.c
> +++ b/drivers/hwtracing/coresight/coresight-tpdm.c
> @@ -86,6 +86,11 @@ static ssize_t tpdm_simple_dataset_show(struct device *dev,
>   			return -EINVAL;
>   		return sysfs_emit(buf, "0x%x\n",
>   			drvdata->cmb->patt_mask[tpdm_attr->idx]);
> +	case CMB_MSR:
> +		if (tpdm_attr->idx >= drvdata->cmb_msr_num)
> +			return -EINVAL;
> +		return sysfs_emit(buf, "0x%x\n",
> +				drvdata->cmb->msr[tpdm_attr->idx]);
>   	}
>   	return -EINVAL;
>   }
> @@ -162,6 +167,12 @@ static ssize_t tpdm_simple_dataset_store(struct device *dev,
>   		else
>   			ret = -EINVAL;
>   		break;
> +	case CMB_MSR:
> +		if (tpdm_attr->idx < drvdata->cmb_msr_num)
> +			drvdata->cmb->msr[tpdm_attr->idx] = val;
> +		else
> +			ret = -EINVAL;


minor nit: Could we not break from here instead of adding return -EINVAL
for each case ? (I understand it has been done for the existing cases.
But I think we should clean up all of that, including the ones you added
in Patch 5. Similarly for the dataset_show()


Suzuki


> +		break;
>   	default:
>   		ret = -EINVAL;
>   	}
> @@ -220,6 +231,23 @@ static umode_t tpdm_dsb_msr_is_visible(struct kobject *kobj,
>   	return 0;
>   }
>   
> +static umode_t tpdm_cmb_msr_is_visible(struct kobject *kobj,
> +				       struct attribute *attr, int n)
> +{
> +	struct device *dev = kobj_to_dev(kobj);
> +	struct tpdm_drvdata *drvdata = dev_get_drvdata(dev->parent);
> +
> +	struct device_attribute *dev_attr =
> +		container_of(attr, struct device_attribute, attr);
> +	struct tpdm_dataset_attribute *tpdm_attr =
> +		container_of(dev_attr, struct tpdm_dataset_attribute, attr);
> +
> +	if (tpdm_attr->idx < drvdata->cmb_msr_num)
> +		return attr->mode;
> +
> +	return 0;
> +}
> +
>   static void tpdm_reset_datasets(struct tpdm_drvdata *drvdata)
>   {
>   	if (tpdm_has_dsb_dataset(drvdata)) {
> @@ -361,6 +389,15 @@ static void set_cmb_tier(struct tpdm_drvdata *drvdata)
>   	writel_relaxed(val, drvdata->base + TPDM_CMB_TIER);
>   }
>   
> +static void set_cmb_msr(struct tpdm_drvdata *drvdata)
> +{
> +	int i;
> +
> +	for (i = 0; i < drvdata->cmb_msr_num; i++)
> +		writel_relaxed(drvdata->cmb->msr[i],
> +			   drvdata->base + TPDM_CMB_MSR(i));
> +}
> +
>   static void tpdm_enable_cmb(struct tpdm_drvdata *drvdata)
>   {
>   	u32 val, i;
> @@ -379,6 +416,8 @@ static void tpdm_enable_cmb(struct tpdm_drvdata *drvdata)
>   
>   	set_cmb_tier(drvdata);
>   
> +	set_cmb_msr(drvdata);
> +
>   	val = readl_relaxed(drvdata->base + TPDM_CMB_CR);
>   	/*
>   	 * Set to 0 for continuous CMB collection mode,
> @@ -1084,6 +1123,42 @@ static struct attribute *tpdm_cmb_patt_attrs[] = {
>   	NULL,
>   };
>   
> +static struct attribute *tpdm_cmb_msr_attrs[] = {
> +	CMB_MSR_ATTR(0),
> +	CMB_MSR_ATTR(1),
> +	CMB_MSR_ATTR(2),
> +	CMB_MSR_ATTR(3),
> +	CMB_MSR_ATTR(4),
> +	CMB_MSR_ATTR(5),
> +	CMB_MSR_ATTR(6),
> +	CMB_MSR_ATTR(7),
> +	CMB_MSR_ATTR(8),
> +	CMB_MSR_ATTR(9),
> +	CMB_MSR_ATTR(10),
> +	CMB_MSR_ATTR(11),
> +	CMB_MSR_ATTR(12),
> +	CMB_MSR_ATTR(13),
> +	CMB_MSR_ATTR(14),
> +	CMB_MSR_ATTR(15),
> +	CMB_MSR_ATTR(16),
> +	CMB_MSR_ATTR(17),
> +	CMB_MSR_ATTR(18),
> +	CMB_MSR_ATTR(19),
> +	CMB_MSR_ATTR(20),
> +	CMB_MSR_ATTR(21),
> +	CMB_MSR_ATTR(22),
> +	CMB_MSR_ATTR(23),
> +	CMB_MSR_ATTR(24),
> +	CMB_MSR_ATTR(25),
> +	CMB_MSR_ATTR(26),
> +	CMB_MSR_ATTR(27),
> +	CMB_MSR_ATTR(28),
> +	CMB_MSR_ATTR(29),
> +	CMB_MSR_ATTR(30),
> +	CMB_MSR_ATTR(31),
> +	NULL,
> +};
> +
>   static struct attribute *tpdm_dsb_attrs[] = {
>   	&dev_attr_dsb_mode.attr,
>   	&dev_attr_dsb_trig_ts.attr,
> @@ -1144,6 +1219,12 @@ static struct attribute_group tpdm_cmb_patt_grp = {
>   	.name = "cmb_patt",
>   };
>   
> +static struct attribute_group tpdm_cmb_msr_grp = {
> +	.attrs = tpdm_cmb_msr_attrs,
> +	.is_visible = tpdm_cmb_msr_is_visible,
> +	.name = "cmb_msr",
> +};
> +
>   static const struct attribute_group *tpdm_attr_grps[] = {
>   	&tpdm_attr_grp,
>   	&tpdm_dsb_attr_grp,
> @@ -1154,6 +1235,7 @@ static const struct attribute_group *tpdm_attr_grps[] = {
>   	&tpdm_cmb_attr_grp,
>   	&tpdm_cmb_trig_patt_grp,
>   	&tpdm_cmb_patt_grp,
> +	&tpdm_cmb_msr_grp,
>   	NULL,
>   };
>   
> @@ -1192,6 +1274,10 @@ static int tpdm_probe(struct amba_device *adev, const struct amba_id *id)
>   		of_property_read_u32(drvdata->dev->of_node,
>   			   "qcom,dsb-msrs-num", &drvdata->dsb_msr_num);
>   
> +	if (drvdata && tpdm_has_cmb_dataset(drvdata))
> +		of_property_read_u32(drvdata->dev->of_node,
> +			   "qcom,cmb-msrs-num", &drvdata->cmb_msr_num);
> +
>   	/* Set up coresight component description */
>   	desc.name = coresight_alloc_device_name(&tpdm_devs, dev);
>   	if (!desc.name)
> diff --git a/drivers/hwtracing/coresight/coresight-tpdm.h b/drivers/hwtracing/coresight/coresight-tpdm.h
> index 65b7ca6c4077..255104d024ab 100644
> --- a/drivers/hwtracing/coresight/coresight-tpdm.h
> +++ b/drivers/hwtracing/coresight/coresight-tpdm.h
> @@ -21,6 +21,8 @@
>   #define TPDM_CMB_XPR(n)		(0xA18 + (n * 4))
>   /*CMB subunit trigger pattern mask registers*/
>   #define TPDM_CMB_XPMR(n)	(0xA20 + (n * 4))
> +/* CMB MSR register */
> +#define TPDM_CMB_MSR(n)		(0xA80 + (n * 4))
>   
>   /* Enable bit for CMB subunit */
>   #define TPDM_CMB_CR_ENA		BIT(0)
> @@ -36,6 +38,9 @@
>   /*Patten register number*/
>   #define TPDM_CMB_MAX_PATT		2
>   
> +/* MAX number of DSB MSR */
> +#define TPDM_CMB_MAX_MSR 32
> +
>   /* DSB Subunit Registers */
>   #define TPDM_DSB_CR		(0x780)
>   #define TPDM_DSB_TIER		(0x784)
> @@ -186,6 +191,10 @@
>   		tpdm_simple_dataset_rw(tpmr##nr,		\
>   		CMB_PATT_MASK, nr)
>   
> +#define CMB_MSR_ATTR(nr)					\
> +		tpdm_simple_dataset_rw(msr##nr,			\
> +		CMB_MSR, nr)
> +
>   /**
>    * struct dsb_dataset - specifics associated to dsb dataset
>    * @mode:             DSB programming mode
> @@ -225,6 +234,7 @@ struct dsb_dataset {
>    * @patt_mask:        Save value for pattern mask
>    * @trig_patt:        Save value for trigger pattern
>    * @trig_patt_mask:   Save value for trigger pattern mask
> + * @msr               Save value for MSR
>    * @patt_ts:          Indicates if pattern match for timestamp is enabled.
>    * @trig_ts:          Indicates if CTI trigger for timestamp is enabled.
>    * @ts_all:           Indicates if timestamp is enabled for all packets.
> @@ -235,6 +245,7 @@ struct cmb_dataset {
>   	u32			patt_mask[TPDM_CMB_MAX_PATT];
>   	u32			trig_patt[TPDM_CMB_MAX_PATT];
>   	u32			trig_patt_mask[TPDM_CMB_MAX_PATT];
> +	u32			msr[TPDM_CMB_MAX_MSR];
>   	bool			patt_ts;
>   	bool			trig_ts;
>   	bool			ts_all;
> @@ -251,6 +262,7 @@ struct cmb_dataset {
>    * @dsb         Specifics associated to TPDM DSB.
>    * @cmb         Specifics associated to TPDM CMB.
>    * @dsb_msr_num Number of MSR supported by DSB TPDM
> + * @cmb_msr_num Number of MSR supported by CMB TPDM
>    */
>   
>   struct tpdm_drvdata {
> @@ -263,6 +275,7 @@ struct tpdm_drvdata {
>   	struct dsb_dataset	*dsb;
>   	struct cmb_dataset	*cmb;
>   	u32			dsb_msr_num;
> +	u32			cmb_msr_num;
>   };
>   
>   /* Enumerate members of various datasets */
> @@ -277,7 +290,8 @@ enum dataset_mem {
>   	CMB_TRIG_PATT,
>   	CMB_TRIG_PATT_MASK,
>   	CMB_PATT,
> -	CMB_PATT_MASK
> +	CMB_PATT_MASK,
> +	CMB_MSR
>   };
>   
>   /**