[PATCH V6 05/26] coresight: etm3x: implementing 'cpu_id()' API

Mathieu Poirier
2015-12-03T21:05:35Z

Other than plainly parsing the device tree there is no way to
know which CPU a tracer is affined to. As such adding an
interface to lookup the CPU field enclosed in the etm_drvdata
structure that was initialised at boot time.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
---
drivers/hwtracing/coresight/coresight-etm3x.c | 8 ++++++++
include/linux/coresight.h | 3 +++
2 files changed, 11 insertions(+)

diff --git a/drivers/hwtracing/coresight/coresight-etm3x.c b/drivers/hwtracing/coresight/coresight-etm3x.c
index b30add73c0ae..9dd88cf8f15c 100644
--- a/drivers/hwtracing/coresight/coresight-etm3x.c
+++ b/drivers/hwtracing/coresight/coresight-etm3x.c
@@ -312,6 +312,13 @@ static void etm_enable_hw(void *info)
dev_dbg(drvdata->dev, "cpu: %d enable smp call done\n", drvdata->cpu);
}

+static int etm_cpu_id(struct coresight_device *csdev)
+{
+ struct etm_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
+
+ return drvdata->cpu;
+}
+
int etm_get_trace_id(struct etm_drvdata *drvdata)
{
unsigned long flags;
@@ -439,6 +446,7 @@ static void etm_disable(struct coresight_device *csdev)
}

static const struct coresight_ops_source etm_source_ops = {
+ .cpu_id = etm_cpu_id,
.trace_id = etm_trace_id,
.enable = etm_enable,
.disable = etm_disable,
diff --git a/include/linux/coresight.h b/include/linux/coresight.h
index a7cabfa23b55..bf62b265bf52 100644
--- a/include/linux/coresight.h
+++ b/include/linux/coresight.h
@@ -205,12 +205,15 @@ struct coresight_ops_link {
/**
* struct coresight_ops_source - basic operations for a source
* Operations available for sources.
+ * @cpu_id: returns the value of the CPU number this component
+ * is associated to.
* @trace_id: returns the value of the component's trace ID as known
to the HW.
* @enable: enables tracing for a source.
* @disable: disables tracing for a source.
*/
struct coresight_ops_source {
+ int (*cpu_id)(struct coresight_device *csdev);
int (*trace_id)(struct coresight_device *csdev);
int (*enable)(struct coresight_device *csdev);
void (*disable)(struct coresight_device *csdev);
--
2.1.4