[4/4] ethdev: add traffic manager query function

diff --git a/lib/ethdev/ethdev_trace.h b/lib/ethdev/ethdev_trace.h
index 3bec87bfdb..dee2819531 100644
--- a/lib/ethdev/ethdev_trace.h
+++ b/lib/ethdev/ethdev_trace.h
@@ -1903,6 +1903,22 @@  RTE_TRACE_POINT(
 	rte_trace_point_emit_int(ret);
 )
 
+RTE_TRACE_POINT(
+	rte_tm_trace_node_query,
+	RTE_TRACE_POINT_ARGS(uint16_t port_id, uint32_t node_id,
+		uint32_t *parent_node_id, uint32_t *priority,
+		uint32_t *weight, uint32_t *level_id,
+		struct rte_tm_node_params *params, int ret),
+	rte_trace_point_emit_u16(port_id);
+	rte_trace_point_emit_u32(node_id);
+	rte_trace_point_emit_ptr(parent_node_id);
+	rte_trace_point_emit_ptr(priority);
+	rte_trace_point_emit_ptr(weight);
+	rte_trace_point_emit_ptr(level_id);
+	rte_trace_point_emit_ptr(params);
+	rte_trace_point_emit_int(ret);
+)
+
 RTE_TRACE_POINT(
 	rte_tm_trace_node_delete,
 	RTE_TRACE_POINT_ARGS(uint16_t port_id, uint32_t node_id, int ret),
diff --git a/lib/ethdev/ethdev_trace_points.c b/lib/ethdev/ethdev_trace_points.c
index 99e04f5893..f5ed7ca637 100644
--- a/lib/ethdev/ethdev_trace_points.c
+++ b/lib/ethdev/ethdev_trace_points.c
@@ -694,6 +694,9 @@  RTE_TRACE_POINT_REGISTER(rte_tm_trace_mark_vlan_dei,
 RTE_TRACE_POINT_REGISTER(rte_tm_trace_node_add,
 	lib.ethdev.tm.node_add)
 
+RTE_TRACE_POINT_REGISTER(rte_tm_trace_node_query,
+	lib.ethdev.tm.node_query)
+
 RTE_TRACE_POINT_REGISTER(rte_tm_trace_node_capabilities_get,
 	lib.ethdev.tm.node_capabilities_get)
 
diff --git a/lib/ethdev/rte_tm.c b/lib/ethdev/rte_tm.c
index 3eb98e618a..8000b66af9 100644
--- a/lib/ethdev/rte_tm.c
+++ b/lib/ethdev/rte_tm.c
@@ -301,6 +301,31 @@  int rte_tm_node_add(uint16_t port_id,
 	return ret;
 }
 
+int rte_tm_node_query(uint16_t port_id,
+	uint32_t node_id,
+	uint32_t *parent_node_id,
+	uint32_t *priority,
+	uint32_t *weight,
+	uint32_t *level_id,
+	struct rte_tm_node_params *params,
+	struct rte_tm_error *error)
+{
+	struct rte_eth_dev *dev = &rte_eth_devices[port_id];
+	int ret;
+
+	if (dev == NULL)
+		return -EINVAL;
+
+	ret = RTE_TM_FUNC(port_id, node_query)(dev,
+		node_id, parent_node_id, priority, weight, level_id,
+		params, error);
+
+	rte_tm_trace_node_query(port_id, node_id, parent_node_id, priority,
+			      weight, level_id, params, ret);
+
+	return ret;
+}
+
 /* Delete node from traffic manager hierarchy */
 int rte_tm_node_delete(uint16_t port_id,
 	uint32_t node_id,
diff --git a/lib/ethdev/rte_tm.h b/lib/ethdev/rte_tm.h
index e5da9b8323..419e491043 100644
--- a/lib/ethdev/rte_tm.h
+++ b/lib/ethdev/rte_tm.h
@@ -1599,6 +1599,54 @@  rte_tm_node_add(uint16_t port_id,
 	const struct rte_tm_node_params *params,
 	struct rte_tm_error *error);
 
+/**
+ * Return information about a traffic management node
+ *
+ * Return information about a hierarchy node, using the same format of parameters
+ * as was passed to the rte_rm_node_add() function.
+ * Each of the "out" parameters pointers (except error) may be passed as NULL if the
+ * information is not needed by the caller. For example, to one may check if a node id
+ * is in use by:
+ *
+ *  struct rte_tm_error error;
+ *  int ret = rte_tm_node_query(port, node_id, NULL, NULL, NULL, NULL, NULL, &error);
+ *  if (ret == ENOENT) ...
+ *
+ * @param[in] port_id
+ *   The port identifier of the Ethernet device.
+ * @param[in] node_id
+ *   Node ID. Should be a valid node id.
+ * @param[out] parent_node_id
+ *   Parent node ID.
+ * @param[out] priority
+ *   Node priority. The highest node priority is zero. Used by the SP algorithm
+ *   running on the parent of the current node for scheduling this child node.
+ * @param[out] weight
+ *   Node weight. The node weight is relative to the weight sum of all siblings
+ *   that have the same priority. The lowest weight is one. Used by the WFQ
+ *   algorithm running on the parent of the current node for scheduling this
+ *   child node.
+ * @param[out] level_id
+ *   The node level in the scheduler hierarchy.
+ * @param[out] params
+ *   Node parameters, as would be used when creating the node.
+ * @param[out] error
+ *   Error details. Filled in only on error, when not NULL.
+ * @return
+ *   0 on success, non-zero error code otherwise.
+ *   -EINVAL - port or node id value is invalid
+ *   -ENOENT - no node exists with the provided id
+ */
+int
+rte_tm_node_query(uint16_t port_id,
+	uint32_t node_id,
+	uint32_t *parent_node_id,
+	uint32_t *priority,
+	uint32_t *weight,
+	uint32_t *level_id,
+	struct rte_tm_node_params *params,
+	struct rte_tm_error *error);
+
 /**
  * Traffic manager node delete
  *
diff --git a/lib/ethdev/rte_tm_driver.h b/lib/ethdev/rte_tm_driver.h
index 6c2618c0d8..fc67f1cb4b 100644
--- a/lib/ethdev/rte_tm_driver.h
+++ b/lib/ethdev/rte_tm_driver.h
@@ -119,6 +119,16 @@  typedef int (*rte_tm_node_resume_t)(struct rte_eth_dev *dev,
 	uint32_t node_id,
 	struct rte_tm_error *error);
 
+/** @internal Traffic manager node query */
+typedef int (*rte_tm_node_query_t)(const struct rte_eth_dev *dev,
+	uint32_t node_id,
+	uint32_t *parent_node_id,
+	uint32_t *priority,
+	uint32_t *weight,
+	uint32_t *level_id,
+	struct rte_tm_node_params *params,
+	struct rte_tm_error *error);
+
 /** @internal Traffic manager hierarchy commit */
 typedef int (*rte_tm_hierarchy_commit_t)(struct rte_eth_dev *dev,
 	int clear_on_fail,
@@ -248,6 +258,8 @@  struct rte_tm_ops {
 	rte_tm_node_suspend_t node_suspend;
 	/** Traffic manager node resume */
 	rte_tm_node_resume_t node_resume;
+	/** Traffic manager node resume */
+	rte_tm_node_query_t node_query;
 	/** Traffic manager hierarchy commit */
 	rte_tm_hierarchy_commit_t hierarchy_commit;