[PATCH v4 08/13] coresight-etm4x: Controls pertaining to the counter functions

From: Mathieu Poirier
Date: Wed May 13 2015 - 12:35:16 EST


From: Pratik Patel <pratikp@xxxxxxxxxxxxxx>

Adding sysfs entries related to the counter functionality, more
specifically to set, control and reload the counters.

Signed-off-by: Pratik Patel <pratikp@xxxxxxxxxxxxxx>
Signed-off-by: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
---
.../ABI/testing/sysfs-bus-coresight-devices-etm4x | 26 ++++
drivers/hwtracing/coresight/coresight-etm4x.c | 144 +++++++++++++++++++++
2 files changed, 170 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-bus-coresight-devices-etm4x b/Documentation/ABI/testing/sysfs-bus-coresight-devices-etm4x
index 6fb43e4c5939..104f3951c998 100644
--- a/Documentation/ABI/testing/sysfs-bus-coresight-devices-etm4x
+++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-etm4x
@@ -204,3 +204,29 @@ KernelVersion: 4.01
Contact: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
Description: (RW) Moves the sequencer to state 0 when a programmed event
occurs.
+
+What: /sys/bus/coresight/devices/<memory_map>.etm/cntr_idx
+Date: April 2015
+KernelVersion: 4.01
+Contact: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
+Description: (RW) Select which counter unit to work with.
+
+What: /sys/bus/coresight/devices/<memory_map>.etm/cntrldvr
+Date: April 2015
+KernelVersion: 4.01
+Contact: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
+Description: (RW) This sets or returns the reload count value of the
+ specific counter.
+
+What: /sys/bus/coresight/devices/<memory_map>.etm/cntr_val
+Date: April 2015
+KernelVersion: 4.01
+Contact: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
+Description: (RW) This sets or returns the current count value of the
+ specific counter.
+
+What: /sys/bus/coresight/devices/<memory_map>.etm/cntr_ctrl
+Date: April 2015
+KernelVersion: 4.01
+Contact: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
+Description: (RW) Controls the operation of the selected counter.
diff --git a/drivers/hwtracing/coresight/coresight-etm4x.c b/drivers/hwtracing/coresight/coresight-etm4x.c
index aa9009fd2377..2c394e41b0c8 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x.c
@@ -1567,6 +1567,146 @@ static ssize_t seq_reset_event_store(struct device *dev,
}
static DEVICE_ATTR_RW(seq_reset_event);

+static ssize_t cntr_idx_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ unsigned long val;
+ struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
+
+ val = drvdata->cntr_idx;
+ return scnprintf(buf, PAGE_SIZE, "%#lx\n", val);
+}
+
+static ssize_t cntr_idx_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t size)
+{
+ unsigned long val;
+ struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
+
+ if (kstrtoul(buf, 16, &val))
+ return -EINVAL;
+ if (val >= drvdata->nr_cntr)
+ return -EINVAL;
+
+ /*
+ * Use spinlock to ensure index doesn't change while it gets
+ * dereferenced multiple times within a spinlock block elsewhere.
+ */
+ spin_lock(&drvdata->spinlock);
+ drvdata->cntr_idx = val;
+ spin_unlock(&drvdata->spinlock);
+ return size;
+}
+static DEVICE_ATTR_RW(cntr_idx);
+
+static ssize_t cntrldvr_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ u8 idx;
+ unsigned long val;
+ struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
+
+ spin_lock(&drvdata->spinlock);
+ idx = drvdata->cntr_idx;
+ val = drvdata->cntrldvr[idx];
+ spin_unlock(&drvdata->spinlock);
+ return scnprintf(buf, PAGE_SIZE, "%#lx\n", val);
+}
+
+static ssize_t cntrldvr_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t size)
+{
+ u8 idx;
+ unsigned long val;
+ struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
+
+ if (kstrtoul(buf, 16, &val))
+ return -EINVAL;
+ if (val > ETM_CNTR_MAX_VAL)
+ return -EINVAL;
+
+ spin_lock(&drvdata->spinlock);
+ idx = drvdata->cntr_idx;
+ drvdata->cntrldvr[idx] = val;
+ spin_unlock(&drvdata->spinlock);
+ return size;
+}
+static DEVICE_ATTR_RW(cntrldvr);
+
+static ssize_t cntr_val_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ u8 idx;
+ unsigned long val;
+ struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
+
+ spin_lock(&drvdata->spinlock);
+ idx = drvdata->cntr_idx;
+ val = drvdata->cntr_val[idx];
+ spin_unlock(&drvdata->spinlock);
+ return scnprintf(buf, PAGE_SIZE, "%#lx\n", val);
+}
+
+static ssize_t cntr_val_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t size)
+{
+ u8 idx;
+ unsigned long val;
+ struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
+
+ if (kstrtoul(buf, 16, &val))
+ return -EINVAL;
+ if (val > ETM_CNTR_MAX_VAL)
+ return -EINVAL;
+
+ spin_lock(&drvdata->spinlock);
+ idx = drvdata->cntr_idx;
+ drvdata->cntr_val[idx] = val;
+ spin_unlock(&drvdata->spinlock);
+ return size;
+}
+static DEVICE_ATTR_RW(cntr_val);
+
+static ssize_t cntr_ctrl_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ u8 idx;
+ unsigned long val;
+ struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
+
+ spin_lock(&drvdata->spinlock);
+ idx = drvdata->cntr_idx;
+ val = drvdata->cntr_ctrl[idx];
+ spin_unlock(&drvdata->spinlock);
+ return scnprintf(buf, PAGE_SIZE, "%#lx\n", val);
+}
+
+static ssize_t cntr_ctrl_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t size)
+{
+ u8 idx;
+ unsigned long val;
+ struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
+
+ if (kstrtoul(buf, 16, &val))
+ return -EINVAL;
+
+ spin_lock(&drvdata->spinlock);
+ idx = drvdata->cntr_idx;
+ drvdata->cntr_ctrl[idx] = val;
+ spin_unlock(&drvdata->spinlock);
+ return size;
+}
+static DEVICE_ATTR_RW(cntr_ctrl);
+
static ssize_t cpu_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
@@ -1613,6 +1753,10 @@ static struct attribute *coresight_etmv4_attrs[] = {
&dev_attr_seq_state.attr,
&dev_attr_seq_event.attr,
&dev_attr_seq_reset_event.attr,
+ &dev_attr_cntr_idx.attr,
+ &dev_attr_cntrldvr.attr,
+ &dev_attr_cntr_val.attr,
+ &dev_attr_cntr_ctrl.attr,
&dev_attr_cpu.attr,
NULL,
};
--
1.9.1

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