[PATCH v3 1/3] ethdev: add traffic manager query function

[Bruce Richardson <bruce.richardson@intel.com>]

Add function to allow querying a node in the scheduler tree.  Returns
the parameters as were given to the add function. Adding this function
allows apps to just query the hierarchy rather than having to maintain
their own copies of it internally.

Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>

---
v2: address feedback
* dropped unnecessary NULL check
* corrected comments
---
 lib/ethdev/ethdev_trace.h        | 16 ++++++++++
 lib/ethdev/ethdev_trace_points.c |  3 ++
 lib/ethdev/rte_tm.c              | 22 ++++++++++++++
 lib/ethdev/rte_tm.h              | 50 ++++++++++++++++++++++++++++++++
 lib/ethdev/rte_tm_driver.h       | 12 ++++++++
 lib/ethdev/version.map           |  1 +
 6 files changed, 104 insertions(+)

diff --git a/lib/ethdev/ethdev_trace.h b/lib/ethdev/ethdev_trace.h
index 738d9829af..70fd6214fc 100644
--- a/lib/ethdev/ethdev_trace.h
+++ b/lib/ethdev/ethdev_trace.h
@@ -1905,6 +1905,22 @@ 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 902e4f7533..eee23613b8 100644
--- a/lib/ethdev/ethdev_trace_points.c
+++ b/lib/ethdev/ethdev_trace_points.c
@@ -706,6 +706,9 @@ 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 d594fe0049..f3e466e690 100644
--- a/lib/ethdev/rte_tm.c
+++ b/lib/ethdev/rte_tm.c
@@ -301,6 +301,28 @@ 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;
+
+	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 07028c9b36..a2b123a19b 100644
--- a/lib/ethdev/rte_tm.h
+++ b/lib/ethdev/rte_tm.h
@@ -20,6 +20,7 @@
 
 #include <rte_common.h>
 #include <rte_meter.h>
+#include <rte_compat.h>
 
 #ifdef __cplusplus
 extern "C" {
@@ -1599,6 +1600,55 @@ rte_tm_node_add(uint16_t port_id,
 	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. Must not be 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 on the provided port
+ */
+__rte_experimental
+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 45290fb3fd..62ceab2cbc 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 query */
+	rte_tm_node_query_t node_query;
 	/** Traffic manager hierarchy commit */
 	rte_tm_hierarchy_commit_t hierarchy_commit;
 
diff --git a/lib/ethdev/version.map b/lib/ethdev/version.map
index f63dc32aa2..c1a386eddc 100644
--- a/lib/ethdev/version.map
+++ b/lib/ethdev/version.map
@@ -335,6 +335,7 @@ EXPERIMENTAL {
 	rte_eth_speed_lanes_get_capability;
 	rte_eth_speed_lanes_set;
 	rte_flow_async_create_by_index_with_pattern;
+	rte_tm_node_query;
 };
 
 INTERNAL {
-- 
2.43.0