[PATCH v4 06/10] coresight-tpdm: Add support to configure CMB
Tao Zhang
quic_taozha at quicinc.com
Sun Jan 21 20:27:58 PST 2024
On 1/19/2024 7:53 PM, Suzuki K Poulose wrote:
> On 19/01/2024 03:22, Tao Zhang wrote:
>> TPDM CMB subunits support two forms of CMB data set element creation:
>> continuous and trace-on-change collection mode. Continuous change
>> creates CMB data set elements on every CMBCLK edge. Trace-on-change
>> creates CMB data set elements only when a new data set element differs
>> in value from the previous element in a CMB data set. Set CMB_CR.MODE
>> to 0 for continuous CMB collection mode. Set CMB_CR.MODE to 1 for
>> trace-on-change CMB collection mode.
>>
>> Reviewed-by: James Clark <james.clark at arm.com>
>> Signed-off-by: Tao Zhang <quic_taozha at quicinc.com>
>> Signed-off-by: Jinlong Mao <quic_jinlmao at quicinc.com>
>> ---
>> .../testing/sysfs-bus-coresight-devices-tpdm | 14 +++++
>> drivers/hwtracing/coresight/coresight-tpdm.c | 61 +++++++++++++++++++
>> drivers/hwtracing/coresight/coresight-tpdm.h | 12 ++++
>> 3 files changed, 87 insertions(+)
>>
>> diff --git
>> a/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm
>> b/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm
>> index 4dd49b159543..3ae21ccf3f29 100644
>> --- a/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm
>> +++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm
>> @@ -170,3 +170,17 @@ Contact: Jinlong Mao (QUIC)
>> <quic_jinlmao at quicinc.com>, Tao Zhang (QUIC) <quic_t
>> Description:
>> (RW) Set/Get the MSR(mux select register) for the DSB subunit
>> TPDM.
>> +
>> +What: /sys/bus/coresight/devices/<tpdm-name>/cmb_mode
>> +Date: March 2023
>> +KernelVersion 6.7
>> +Contact: Jinlong Mao (QUIC) <quic_jinlmao at quicinc.com>, Tao Zhang
>> (QUIC) <quic_taozha at quicinc.com>
>> +Description: (Write) Set the data collection mode of CMB tpdm.
>> Continuous
>> + change creates CMB data set elements on every CMBCLK edge.
>> + Trace-on-change creates CMB data set elements only when a new
>> + data set element differs in value from the previous element
>> + in a CMB data set.
>> +
>> + Accepts only one of the 2 values - 0 or 1.
>> + 0 : Continuous CMB collection mode.
>> + 1 : Trace-on-change CMB collection mode.
>> diff --git a/drivers/hwtracing/coresight/coresight-tpdm.c
>> b/drivers/hwtracing/coresight/coresight-tpdm.c
>> index 424a2f724d82..b55aee65a856 100644
>> --- a/drivers/hwtracing/coresight/coresight-tpdm.c
>> +++ b/drivers/hwtracing/coresight/coresight-tpdm.c
>> @@ -137,6 +137,18 @@ static umode_t tpdm_dsb_is_visible(struct
>> kobject *kobj,
>> return 0;
>> }
>> +static umode_t tpdm_cmb_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);
>> +
>> + if (drvdata && tpdm_has_cmb_dataset(drvdata))
>> + return attr->mode;
>> +
>> + return 0;
>> +}
>> +
>> static umode_t tpdm_dsb_msr_is_visible(struct kobject *kobj,
>> struct attribute *attr, int n)
>> {
>> @@ -161,6 +173,9 @@ static void tpdm_reset_datasets(struct
>> tpdm_drvdata *drvdata)
>> drvdata->dsb->trig_ts = true;
>> drvdata->dsb->trig_type = false;
>> }
>> +
>> + if (tpdm_has_cmb_dataset(drvdata))
>
> This could simply be gated on drvdata->cmb for extra safety ?
>
> if (drvdata->cmb)
Sure, can I also use "if (drvdata->dsb) " instead of "if
(tpdm_has_dsb_dataset(drvdata))" and update in the same patch?
>
>> + memset(drvdata->cmb, 0, sizeof(struct cmb_dataset));
>> }
>> static void set_dsb_mode(struct tpdm_drvdata *drvdata, u32 *val)
>> @@ -389,6 +404,12 @@ static int tpdm_datasets_setup(struct
>> tpdm_drvdata *drvdata)
>> if (!drvdata->dsb)
>> return -ENOMEM;
>> }
>> + if (tpdm_has_cmb_dataset(drvdata) && (!drvdata->cmb)) {
>> + drvdata->cmb = devm_kzalloc(drvdata->dev,
>> + sizeof(*drvdata->cmb), GFP_KERNEL);
>> + if (!drvdata->cmb)
>> + return -ENOMEM;
>> + }
>> tpdm_reset_datasets(drvdata);
>> return 0;
>> @@ -727,6 +748,35 @@ static ssize_t dsb_trig_ts_store(struct device
>> *dev,
>> }
>> static DEVICE_ATTR_RW(dsb_trig_ts);
>> +static ssize_t cmb_mode_show(struct device *dev,
>> + struct device_attribute *attr,
>> + char *buf)
>> +{
>> + struct tpdm_drvdata *drvdata = dev_get_drvdata(dev->parent);
>> +
>> + return sysfs_emit(buf, "%x\n",
>> + drvdata->cmb->trace_mode);
>
> minor nit: Don't need to split the line here. Also, for completeness,
> you need to read it under spinlock, use guard() to unlock implicitly.
Sure, I will not split the line here in the next patch series.
I didn't add spinlock here because the show function only read the value.
Do you mean I need to add the spinlock to all of the show function?
>
>> +
>> +}
>> +
>> +static ssize_t cmb_mode_store(struct device *dev,
>> + struct device_attribute *attr,
>> + const char *buf,
>> + size_t size)
>> +{
>> + struct tpdm_drvdata *drvdata = dev_get_drvdata(dev->parent);
>> + unsigned long trace_mode;
>> +
>> + if ((kstrtoul(buf, 0, &trace_mode)) || (trace_mode & ~1UL))
>
> minor nit: drop () around kstrtoul()
Sure, I will update in the next patch series.
Best,
Tao
>
> Rest looks fine.
>
> Suzuki
>
>> + return -EINVAL;
>> +
>> + spin_lock(&drvdata->spinlock);
>> + drvdata->cmb->trace_mode = trace_mode;
>> + spin_unlock(&drvdata->spinlock);
>> + return size;
>> +}
>> +static DEVICE_ATTR_RW(cmb_mode);
>> +
>> static struct attribute *tpdm_dsb_edge_attrs[] = {
>> &dev_attr_ctrl_idx.attr,
>> &dev_attr_ctrl_val.attr,
>> @@ -843,6 +893,11 @@ static struct attribute *tpdm_dsb_attrs[] = {
>> NULL,
>> };
>> +static struct attribute *tpdm_cmb_attrs[] = {
>> + &dev_attr_cmb_mode.attr,
>> + NULL,
>> +};
>> +
>> static struct attribute_group tpdm_dsb_attr_grp = {
>> .attrs = tpdm_dsb_attrs,
>> .is_visible = tpdm_dsb_is_visible,
>> @@ -872,6 +927,11 @@ static struct attribute_group tpdm_dsb_msr_grp = {
>> .name = "dsb_msr",
>> };
>> +static struct attribute_group tpdm_cmb_attr_grp = {
>> + .attrs = tpdm_cmb_attrs,
>> + .is_visible = tpdm_cmb_is_visible,
>> +};
>> +
>> static const struct attribute_group *tpdm_attr_grps[] = {
>> &tpdm_attr_grp,
>> &tpdm_dsb_attr_grp,
>> @@ -879,6 +939,7 @@ static const struct attribute_group
>> *tpdm_attr_grps[] = {
>> &tpdm_dsb_trig_patt_grp,
>> &tpdm_dsb_patt_grp,
>> &tpdm_dsb_msr_grp,
>> + &tpdm_cmb_attr_grp,
>> NULL,
>> };
>> diff --git a/drivers/hwtracing/coresight/coresight-tpdm.h
>> b/drivers/hwtracing/coresight/coresight-tpdm.h
>> index a442d9c6e4ac..2af92c270ed1 100644
>> --- a/drivers/hwtracing/coresight/coresight-tpdm.h
>> +++ b/drivers/hwtracing/coresight/coresight-tpdm.h
>> @@ -14,6 +14,8 @@
>> /* Enable bit for CMB subunit */
>> #define TPDM_CMB_CR_ENA BIT(0)
>> +/* Trace collection mode for CMB subunit */
>> +#define TPDM_CMB_CR_MODE BIT(1)
>> /* DSB Subunit Registers */
>> #define TPDM_DSB_CR (0x780)
>> @@ -181,6 +183,14 @@ struct dsb_dataset {
>> bool trig_type;
>> };
>> +/**
>> + * struct cmb_dataset
>> + * @trace_mode: Dataset collection mode
>> + */
>> +struct cmb_dataset {
>> + u32 trace_mode;
>> +};
>> +
>> /**
>> * struct tpdm_drvdata - specifics associated to an TPDM component
>> * @base: memory mapped base address for this component.
>> @@ -190,6 +200,7 @@ struct dsb_dataset {
>> * @enable: enable status of the component.
>> * @datasets: The datasets types present of the TPDM.
>> * @dsb Specifics associated to TPDM DSB.
>> + * @cmb Specifics associated to TPDM CMB.
>> * @dsb_msr_num Number of MSR supported by DSB TPDM
>> */
>> @@ -201,6 +212,7 @@ struct tpdm_drvdata {
>> bool enable;
>> unsigned long datasets;
>> struct dsb_dataset *dsb;
>> + struct cmb_dataset *cmb;
>> u32 dsb_msr_num;
>> };
>
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