coresight: Emit sink ID in the HW_ID packets

For Perf to be able to decode when per-sink trace IDs are used, emit the
sink that's being written to for each ETM.

Perf currently errors out if it sees a newer packet version so instead
of bumping it, add a new minor version field. This can be used to
signify new versions that have backwards compatible fields. Considering
this change is only for high core count machines, it doesn't make sense
to make a breaking change for everyone.

Signed-off-by: James Clark <james.clark@arm.com>
Tested-by: Leo Yan <leo.yan@arm.com>
Reviewed-by: Mike Leach <mike.leach@linaro.org>
Signed-off-by: James Clark <james.clark@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20240722101202.26915-17-james.clark@linaro.org

3 files changed, 26 insertions, 17 deletions

diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c
index faf560ba8d64..c427e9344a84 100644
--- a/drivers/hwtracing/coresight/coresight-core.c
+++ b/drivers/hwtracing/coresight/coresight-core.c
@@ -487,23 +487,25 @@ struct coresight_device *coresight_get_sink(struct list_head *path)
 	return csdev;
 }
 
+u32 coresight_get_sink_id(struct coresight_device *csdev)
+{
+	if (!csdev->ea)
+		return 0;
+
+	/*
+	 * See function etm_perf_add_symlink_sink() to know where
+	 * this comes from.
+	 */
+	return (u32) (unsigned long) csdev->ea->var;
+}
+
 static int coresight_sink_by_id(struct device *dev, const void *data)
 {
 	struct coresight_device *csdev = to_coresight_device(dev);
-	unsigned long hash;
 
 	if (csdev->type == CORESIGHT_DEV_TYPE_SINK ||
-	     csdev->type == CORESIGHT_DEV_TYPE_LINKSINK) {
-
-		if (!csdev->ea)
-			return 0;
-		/*
-		 * See function etm_perf_add_symlink_sink() to know where
-		 * this comes from.
-		 */
-		hash = (unsigned long)csdev->ea->var;
-
-		if ((u32)hash == *(u32 *)data)
+	    csdev->type == CORESIGHT_DEV_TYPE_LINKSINK) {
+		if (coresight_get_sink_id(csdev) == *(u32 *)data)
 			return 1;
 	}
 
diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.c b/drivers/hwtracing/coresight/coresight-etm-perf.c
index 70c99f0409b2..ad6a8f4b70b6 100644
--- a/drivers/hwtracing/coresight/coresight-etm-perf.c
+++ b/drivers/hwtracing/coresight/coresight-etm-perf.c
@@ -460,6 +460,7 @@ static void etm_event_start(struct perf_event *event, int flags)
 	struct coresight_device *sink, *csdev = per_cpu(csdev_src, cpu);
 	struct list_head *path;
 	u64 hw_id;
+	u8 trace_id;
 
 	if (!csdev)
 		goto fail;
@@ -512,11 +513,16 @@ static void etm_event_start(struct perf_event *event, int flags)
 	 */
 	if (!cpumask_test_cpu(cpu, &event_data->aux_hwid_done)) {
 		cpumask_set_cpu(cpu, &event_data->aux_hwid_done);
-		hw_id = FIELD_PREP(CS_AUX_HW_ID_VERSION_MASK,
-				   CS_AUX_HW_ID_CURR_VERSION);
-		hw_id |= FIELD_PREP(CS_AUX_HW_ID_TRACE_ID_MASK,
-				    coresight_trace_id_read_cpu_id_map(cpu,
-								       &sink->perf_sink_id_map));
+
+		trace_id = coresight_trace_id_read_cpu_id_map(cpu, &sink->perf_sink_id_map);
+
+		hw_id = FIELD_PREP(CS_AUX_HW_ID_MAJOR_VERSION_MASK,
+				CS_AUX_HW_ID_MAJOR_VERSION);
+		hw_id |= FIELD_PREP(CS_AUX_HW_ID_MINOR_VERSION_MASK,
+				CS_AUX_HW_ID_MINOR_VERSION);
+		hw_id |= FIELD_PREP(CS_AUX_HW_ID_TRACE_ID_MASK, trace_id);
+		hw_id |= FIELD_PREP(CS_AUX_HW_ID_SINK_ID_MASK, coresight_get_sink_id(sink));
+
 		perf_report_aux_output_id(event, hw_id);
 	}
 
diff --git a/drivers/hwtracing/coresight/coresight-priv.h b/drivers/hwtracing/coresight/coresight-priv.h
index 61a46d3bdcc8..05f891ca6b5c 100644
--- a/drivers/hwtracing/coresight/coresight-priv.h
+++ b/drivers/hwtracing/coresight/coresight-priv.h
@@ -148,6 +148,7 @@ int coresight_make_links(struct coresight_device *orig,
 			 struct coresight_device *target);
 void coresight_remove_links(struct coresight_device *orig,
 			    struct coresight_connection *conn);
+u32 coresight_get_sink_id(struct coresight_device *csdev);
 
 #if IS_ENABLED(CONFIG_CORESIGHT_SOURCE_ETM3X)
 extern int etm_readl_cp14(u32 off, unsigned int *val);