[PATCH v4] graph: expose node context as pointers

[Robin Jarry <rjarry@redhat.com>]

In some cases, the node context data is used to store two pointers
because the data is larger than the reserved 16 bytes. Having to define
intermediate structures just to be able to cast is tedious. Add helper
inline functions to cast the node context to opaque pointers.

Signed-off-by: Robin Jarry <rjarry@redhat.com>
---

Notes:
    v4:
    
    * Replaced the unnamed union with helper inline functions.
    
    v3:
    
    * Added __extension__ to the unnamed struct inside the union.
    * Fixed C++ header checks.
    * Replaced alignas() with an explicit static_assert.

 lib/graph/rte_graph_worker_common.h | 54 +++++++++++++++++++++++++++++
 1 file changed, 54 insertions(+)

diff --git a/lib/graph/rte_graph_worker_common.h b/lib/graph/rte_graph_worker_common.h
index 36d864e2c14e..f54f65598193 100644
--- a/lib/graph/rte_graph_worker_common.h
+++ b/lib/graph/rte_graph_worker_common.h
@@ -130,6 +130,60 @@ struct __rte_cache_aligned rte_node {
 	alignas(RTE_CACHE_LINE_MIN_SIZE) struct rte_node *nodes[]; /**< Next nodes. */
 };
 
+/**
+ * Cast the first 8 bytes of node context as an opaque pointer.
+ *
+ * @param node
+ *   Pointer to the node object.
+ *
+ * @return
+ *   The opaque pointer value.
+ */
+static inline void *rte_node_ctx_ptr1_get(struct rte_node *node)
+{
+	return ((void **)node->ctx)[0];
+}
+
+/**
+ * Cast the last 8 bytes of node context as an opaque pointer.
+ *
+ * @param node
+ *   Pointer to the node object.
+ *
+ * @return
+ *   The opaque pointer value.
+ */
+static inline void *rte_node_ctx_ptr2_get(struct rte_node *node)
+{
+	return ((void **)node->ctx)[1];
+}
+
+/**
+ * Set the first 8 bytes of node context to an opaque pointer value.
+ *
+ * @param node
+ *   Pointer to the node object.
+ * @param ptr
+ *   The opaque pointer value.
+ */
+static inline void rte_node_ctx_ptr1_set(struct rte_node *node, void *ptr)
+{
+	((void **)node->ctx)[0] = ptr;
+}
+
+/**
+ * Set the last 8 bytes of node context to an opaque pointer value.
+ *
+ * @param node
+ *   Pointer to the node object.
+ * @param ptr
+ *   The opaque pointer value.
+ */
+static inline void rte_node_ctx_ptr2_set(struct rte_node *node, void *ptr)
+{
+	((void **)node->ctx)[1] = ptr;
+}
+
 /**
  * @internal
  *
-- 
2.44.0