Hi,

On Mon, 14 Jul 2025 at 07:31, Jie Gan jie.gan@oss.qualcomm.com wrote:

Retrieving the helper device of the specific coresight device based on its helper_subtype because a single coresight device may has multiple types of the helper devices.

Signed-off-by: Jie Gan jie.gan@oss.qualcomm.com

drivers/hwtracing/coresight/coresight-core.c | 30 ++++++++++++++++++++ drivers/hwtracing/coresight/coresight-priv.h | 2 ++ 2 files changed, 32 insertions(+)

diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c index 5297a5ff7921..76e10c36a8a1 100644 --- a/drivers/hwtracing/coresight/coresight-core.c +++ b/drivers/hwtracing/coresight/coresight-core.c @@ -580,6 +580,36 @@ struct coresight_device *coresight_get_sink(struct coresight_path *path) } EXPORT_SYMBOL_GPL(coresight_get_sink);

+/**

• • coresight_get_helper: find the helper device of the assigned csdev.
• • @csdev: The csdev the helper device is conntected to.
• • @type: helper_subtype of the expected helper device.
• • Retrieve the helper device for the specific csdev based on its
• • helper_subtype.
• • Return: the helper's csdev upon success or NULL for fail.
• */

+struct coresight_device *coresight_get_helper(struct coresight_device *csdev,

•                                         int type)
  

+{

•   int i;
  

•   struct coresight_device *helper;
  

•   for (i = 0; i < csdev->pdata->nr_outconns; ++i) {
  

•           helper = csdev->pdata->out_conns[i]->dest_dev;
  

•           if (!helper || !coresight_is_helper(helper))
  

•                   continue;
  

Manipulating the connections list almost certainly requires some locking. See other functions in this file

Mike

•           if (helper->subtype.helper_subtype == type)
  

•                   return helper;
  

•   }
  

•   return NULL;
  

+} +EXPORT_SYMBOL_GPL(coresight_get_helper);

/**

• coresight_get_port_helper: get the in-port number of the helper device
• that is connected to the csdev.

diff --git a/drivers/hwtracing/coresight/coresight-priv.h b/drivers/hwtracing/coresight/coresight-priv.h index 07a5f03de81d..5b912eb60401 100644 --- a/drivers/hwtracing/coresight/coresight-priv.h +++ b/drivers/hwtracing/coresight/coresight-priv.h @@ -158,6 +158,8 @@ void coresight_path_assign_trace_id(struct coresight_path *path, enum cs_mode mode); int coresight_get_port_helper(struct coresight_device *csdev, struct coresight_device *helper); +struct coresight_device *coresight_get_helper(struct coresight_device *csdev,

•                                         int type);
  
  

#if IS_ENABLED(CONFIG_CORESIGHT_SOURCE_ETM3X) int etm_readl_cp14(u32 off, unsigned int *val); -- 2.34.1