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.poir...@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 d630b7ece735..755f6f4d6d79 100644
--- a/drivers/hwtracing/coresight/coresight-etm3x.c
+++ b/drivers/hwtracing/coresight/coresight-etm3x.c
@@ -315,6 +315,13 @@ 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;
+}
+
 static int etm_trace_id(struct coresight_device *csdev)
 {
        struct etm_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
@@ -421,6 +428,7 @@ 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

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to