1 files changed, 72 insertions, 14 deletions

diff --git a/drivers/hwtracing/coresight/coresight.c b/drivers/hwtracing/coresight/coresight.c
index ef20f74c85fa..c71553c09f8e 100644
--- a/drivers/hwtracing/coresight/coresight.c
+++ b/drivers/hwtracing/coresight/coresight.c
@@ -216,6 +216,44 @@ void coresight_disclaim_device(void __iomem *base)
 	CS_LOCK(base);
 }
 
+/* enable or disable an associated CTI device of the supplied CS device */
+static int
+coresight_control_assoc_ectdev(struct coresight_device *csdev, bool enable)
+{
+	int ect_ret = 0;
+	struct coresight_device *ect_csdev = csdev->ect_dev;
+
+	if (!ect_csdev)
+		return 0;
+
+	if (enable) {
+		if (ect_ops(ect_csdev)->enable)
+			ect_ret = ect_ops(ect_csdev)->enable(ect_csdev);
+	} else {
+		if (ect_ops(ect_csdev)->disable)
+			ect_ret = ect_ops(ect_csdev)->disable(ect_csdev);
+	}
+
+	/* output warning if ECT enable is preventing trace operation */
+	if (ect_ret)
+		dev_info(&csdev->dev, "Associated ECT device (%s) %s failed\n",
+			 dev_name(&ect_csdev->dev),
+			 enable ? "enable" : "disable");
+	return ect_ret;
+}
+
+/*
+ * Set the associated ect / cti device while holding the coresight_mutex
+ * to avoid a race with coresight_enable that may try to use this value.
+ */
+void coresight_set_assoc_ectdev_mutex(struct coresight_device *csdev,
+				      struct coresight_device *ect_csdev)
+{
+	mutex_lock(&coresight_mutex);
+	csdev->ect_dev = ect_csdev;
+	mutex_unlock(&coresight_mutex);
+}
+
 static int coresight_enable_sink(struct coresight_device *csdev,
 				 u32 mode, void *data)
 {
@@ -228,9 +266,14 @@ static int coresight_enable_sink(struct coresight_device *csdev,
 	if (!sink_ops(csdev)->enable)
 		return -EINVAL;
 
-	ret = sink_ops(csdev)->enable(csdev, mode, data);
+	ret = coresight_control_assoc_ectdev(csdev, true);
 	if (ret)
 		return ret;
+	ret = sink_ops(csdev)->enable(csdev, mode, data);
+	if (ret) {
+		coresight_control_assoc_ectdev(csdev, false);
+		return ret;
+	}
 	csdev->enable = true;
 
 	return 0;
@@ -246,6 +289,7 @@ static void coresight_disable_sink(struct coresight_device *csdev)
 	ret = sink_ops(csdev)->disable(csdev);
 	if (ret)
 		return;
+	coresight_control_assoc_ectdev(csdev, false);
 	csdev->enable = false;
 }
 
@@ -269,8 +313,15 @@ static int coresight_enable_link(struct coresight_device *csdev,
 	if (link_subtype == CORESIGHT_DEV_SUBTYPE_LINK_SPLIT && outport < 0)
 		return outport;
 
-	if (link_ops(csdev)->enable)
-		ret = link_ops(csdev)->enable(csdev, inport, outport);
+	if (link_ops(csdev)->enable) {
+		ret = coresight_control_assoc_ectdev(csdev, true);
+		if (!ret) {
+			ret = link_ops(csdev)->enable(csdev, inport, outport);
+			if (ret)
+				coresight_control_assoc_ectdev(csdev, false);
+		}
+	}
+
 	if (!ret)
 		csdev->enable = true;
 
@@ -300,8 +351,10 @@ static void coresight_disable_link(struct coresight_device *csdev,
 		nr_conns = 1;
 	}
 
-	if (link_ops(csdev)->disable)
+	if (link_ops(csdev)->disable) {
 		link_ops(csdev)->disable(csdev, inport, outport);
+		coresight_control_assoc_ectdev(csdev, false);
+	}
 
 	for (i = 0; i < nr_conns; i++)
 		if (atomic_read(&csdev->refcnt[i]) != 0)
@@ -322,9 +375,14 @@ static int coresight_enable_source(struct coresight_device *csdev, u32 mode)
 
 	if (!csdev->enable) {
 		if (source_ops(csdev)->enable) {
-			ret = source_ops(csdev)->enable(csdev, NULL, mode);
+			ret = coresight_control_assoc_ectdev(csdev, true);
 			if (ret)
 				return ret;
+			ret = source_ops(csdev)->enable(csdev, NULL, mode);
+			if (ret) {
+				coresight_control_assoc_ectdev(csdev, false);
+				return ret;
+			};
 		}
 		csdev->enable = true;
 	}
@@ -347,6 +405,7 @@ static bool coresight_disable_source(struct coresight_device *csdev)
 	if (atomic_dec_return(csdev->refcnt) == 0) {
 		if (source_ops(csdev)->disable)
 			source_ops(csdev)->disable(csdev, NULL);
+		coresight_control_assoc_ectdev(csdev, false);
 		csdev->enable = false;
 	}
 	return !csdev->enable;
@@ -955,12 +1014,16 @@ static struct device_type coresight_dev_type[] = {
 	{
 		.name = "helper",
 	},
+	{
+		.name = "ect",
+	},
 };
 
 static void coresight_device_release(struct device *dev)
 {
 	struct coresight_device *csdev = to_coresight_device(dev);
 
+	cti_remove_assoc_from_csdev(csdev);
 	fwnode_handle_put(csdev->dev.fwnode);
 	kfree(csdev->refcnt);
 	kfree(csdev);
@@ -1027,17 +1090,11 @@ static void coresight_fixup_device_conns(struct coresight_device *csdev)
 
 	for (i = 0; i < csdev->pdata->nr_outport; i++) {
 		struct coresight_connection *conn = &csdev->pdata->conns[i];
-		struct device *dev = NULL;
 
-		dev = bus_find_device_by_fwnode(&coresight_bustype, conn->child_fwnode);
-		if (dev) {
-			conn->child_dev = to_coresight_device(dev);
-			/* and put reference from 'bus_find_device()' */
-			put_device(dev);
-		} else {
+		conn->child_dev =
+			coresight_find_csdev_by_fwnode(conn->child_fwnode);
+		if (!conn->child_dev)
 			csdev->orphan = true;
-			conn->child_dev = NULL;
-		}
 	}
 }
 
@@ -1249,6 +1306,7 @@ struct coresight_device *coresight_register(struct coresight_desc *desc)
 
 	coresight_fixup_device_conns(csdev);
 	coresight_fixup_orphan_conns(csdev);
+	cti_add_assoc_to_csdev(csdev);
 
 	mutex_unlock(&coresight_mutex);