coresight: Dynamically add connections

Add a function for adding connections dynamically. This also removes
the 1:1 mapping between port number and the index into the connections
array. The only place this mapping was used was in the warning for
duplicate output ports, which has been replaced by a search. Other
uses of the port number already use the port member variable.

Being able to dynamically add connections will allow other devices like
CTI to re-use the connection mechanism despite not having explicit
connections described in the DT.

The connections array is now no longer sparse, so child_fwnode doesn't
need to be checked as all connections have a target node. Because the
array is no longer sparse, the high in and out port numbers are required
for the refcount arrays. But these will also be removed in a later
commit when the refcount is made a property of the connection.

Reviewed-by: Mike Leach <mike.leach@linaro.org>
Signed-off-by: James Clark <james.clark@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20230425143542.2305069-7-james.clark@arm.com

1 files changed, 8 insertions, 15 deletions

diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c
index f3dc320b374c..91274e7e6944 100644
--- a/drivers/hwtracing/coresight/coresight-core.c
+++ b/drivers/hwtracing/coresight/coresight-core.c
@@ -397,9 +397,9 @@ static void coresight_disable_link(struct coresight_device *csdev,
 	link_subtype = csdev->subtype.link_subtype;
 
 	if (link_subtype == CORESIGHT_DEV_SUBTYPE_LINK_MERG) {
-		nr_conns = csdev->pdata->nr_inconns;
+		nr_conns = csdev->pdata->high_inport;
 	} else if (link_subtype == CORESIGHT_DEV_SUBTYPE_LINK_SPLIT) {
-		nr_conns = csdev->pdata->nr_outconns;
+		nr_conns = csdev->pdata->high_outport;
 	} else {
 		nr_conns = 1;
 	}
@@ -1336,9 +1336,6 @@ static int coresight_orphan_match(struct device *dev, void *data)
 	for (i = 0; i < i_csdev->pdata->nr_outconns; i++) {
 		conn = &i_csdev->pdata->out_conns[i];
 
-		/* Skip the port if FW doesn't describe it */
-		if (!conn->dest_fwnode)
-			continue;
 		/* We have found at least one orphan connection */
 		if (conn->dest_dev == NULL) {
 			/* Does it match this newly added device? */
@@ -1377,8 +1374,6 @@ static int coresight_fixup_device_conns(struct coresight_device *csdev)
 	for (i = 0; i < csdev->pdata->nr_outconns; i++) {
 		struct coresight_connection *conn = &csdev->pdata->out_conns[i];
 
-		if (!conn->dest_fwnode)
-			continue;
 		conn->dest_dev =
 			coresight_find_csdev_by_fwnode(conn->dest_fwnode);
 		if (conn->dest_dev && conn->dest_dev->has_conns_grp) {
@@ -1413,7 +1408,7 @@ static int coresight_remove_match(struct device *dev, void *data)
 	for (i = 0; i < iterator->pdata->nr_outconns; i++) {
 		conn = &iterator->pdata->out_conns[i];
 
-		if (conn->dest_dev == NULL || conn->dest_fwnode == NULL)
+		if (conn->dest_dev == NULL)
 			continue;
 
 		if (csdev->dev.fwnode == conn->dest_fwnode) {
@@ -1445,7 +1440,7 @@ static void coresight_remove_conns(struct coresight_device *csdev)
 	 * doesn't have at least one input port, there is no point
 	 * in searching all the devices.
 	 */
-	if (csdev->pdata->nr_inconns)
+	if (csdev->pdata->high_inport)
 		bus_for_each_dev(&coresight_bustype, NULL,
 				 csdev, coresight_remove_match);
 }
@@ -1552,10 +1547,8 @@ void coresight_release_platform_data(struct coresight_device *csdev,
 		 * Drop the refcount and clear the handle as this device
 		 * is going away
 		 */
-		if (conns[i].dest_fwnode) {
-			fwnode_handle_put(conns[i].dest_fwnode);
-			conns[i].dest_fwnode = NULL;
-		}
+		fwnode_handle_put(conns[i].dest_fwnode);
+		conns[i].dest_fwnode = NULL;
 	}
 	if (csdev)
 		coresight_remove_conns_sysfs_group(csdev);
@@ -1581,9 +1574,9 @@ struct coresight_device *coresight_register(struct coresight_desc *desc)
 		link_subtype = desc->subtype.link_subtype;
 
 		if (link_subtype == CORESIGHT_DEV_SUBTYPE_LINK_MERG)
-			nr_refcnts = desc->pdata->nr_inconns;
+			nr_refcnts = desc->pdata->high_inport;
 		else if (link_subtype == CORESIGHT_DEV_SUBTYPE_LINK_SPLIT)
-			nr_refcnts = desc->pdata->nr_outconns;
+			nr_refcnts = desc->pdata->high_outport;
 	}
 
 	refcnts = kcalloc(nr_refcnts, sizeof(*refcnts), GFP_KERNEL);