Re: [PATCH v4 06/10] coresight-tpdm: Add support to configure CMB
From: Tao Zhang
Date: Sun Jan 21 2024 - 23:28:45 EST
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@xxxxxxx>
Signed-off-by: Tao Zhang <quic_taozha@xxxxxxxxxxx>
Signed-off-by: Jinlong Mao <quic_jinlmao@xxxxxxxxxxx>
---
.../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@xxxxxxxxxxx>, 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@xxxxxxxxxxx>, Tao Zhang
(QUIC) <quic_taozha@xxxxxxxxxxx>
+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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