[V3,2/7] table: add entry ID for learner tables

diff --git a/lib/pipeline/rte_swx_pipeline.c b/lib/pipeline/rte_swx_pipeline.c
index e271cc50eb..80108b8916 100644
--- a/lib/pipeline/rte_swx_pipeline.c
+++ b/lib/pipeline/rte_swx_pipeline.c
@@ -2556,6 +2556,7 @@  instr_learner_exec(struct rte_swx_pipeline *p)
 	struct learner_statistics *stats = &p->learner_stats[learner_id];
 	uint64_t action_id, n_pkts_hit, n_pkts_action, time;
 	uint8_t *action_data;
+	size_t entry_id;
 	int done, hit;
 
 	/* Table. */
@@ -2567,6 +2568,7 @@  instr_learner_exec(struct rte_swx_pipeline *p)
 					    l->key,
 					    &action_id,
 					    &action_data,
+					    &entry_id,
 					    &hit);
 	if (!done) {
 		/* Thread. */
@@ -2580,6 +2582,7 @@  instr_learner_exec(struct rte_swx_pipeline *p)
 
 	action_id = hit ? action_id : ts->default_action_id;
 	action_data = hit ? action_data : ts->default_action_data;
+	entry_id = hit ? (1 + entry_id) : 0;
 	n_pkts_hit = stats->n_pkts_hit[hit];
 	n_pkts_action = stats->n_pkts_action[action_id];
 
@@ -2591,6 +2594,7 @@  instr_learner_exec(struct rte_swx_pipeline *p)
 
 	t->action_id = action_id;
 	t->structs[0] = action_data;
+	t->entry_id = entry_id;
 	t->hit = hit;
 	t->learner_id = learner_id;
 	t->time = time;
@@ -2613,6 +2617,7 @@  instr_learner_af_exec(struct rte_swx_pipeline *p)
 	struct learner_statistics *stats = &p->learner_stats[learner_id];
 	uint64_t action_id, n_pkts_hit, n_pkts_action, time;
 	uint8_t *action_data;
+	size_t entry_id;
 	action_func_t action_func;
 	int done, hit;
 
@@ -2625,6 +2630,7 @@  instr_learner_af_exec(struct rte_swx_pipeline *p)
 					    l->key,
 					    &action_id,
 					    &action_data,
+					    &entry_id,
 					    &hit);
 	if (!done) {
 		/* Thread. */
@@ -2638,6 +2644,7 @@  instr_learner_af_exec(struct rte_swx_pipeline *p)
 
 	action_id = hit ? action_id : ts->default_action_id;
 	action_data = hit ? action_data : ts->default_action_data;
+	entry_id = hit ? (1 + entry_id) : 0;
 	action_func = p->action_funcs[action_id];
 	n_pkts_hit = stats->n_pkts_hit[hit];
 	n_pkts_action = stats->n_pkts_action[action_id];
@@ -2650,6 +2657,7 @@  instr_learner_af_exec(struct rte_swx_pipeline *p)
 
 	t->action_id = action_id;
 	t->structs[0] = action_data;
+	t->entry_id = entry_id;
 	t->hit = hit;
 	t->learner_id = learner_id;
 	t->time = time;
diff --git a/lib/table/rte_swx_table_learner.c b/lib/table/rte_swx_table_learner.c
index c1045a1082..996fd3de5b 100644
--- a/lib/table/rte_swx_table_learner.c
+++ b/lib/table/rte_swx_table_learner.c
@@ -72,6 +72,7 @@  table_keycpy(void *dst, void *src, uint32_t n_bytes)
 }
 
 #define TABLE_KEYS_PER_BUCKET 4
+#define TABLE_KEYS_PER_BUCKET_LOG2 2
 
 #define TABLE_BUCKET_USEFUL_SIZE \
 	(TABLE_KEYS_PER_BUCKET * (sizeof(uint32_t) + sizeof(uint32_t) + sizeof(uint8_t)))
@@ -263,6 +264,14 @@  table_bucket_data_get(struct table *t, struct table_bucket *b, size_t bucket_key
 				   (bucket_key_pos << t->params.data_size_log2)];
 }
 
+static inline size_t
+table_entry_id_get(struct table *t, struct table_bucket *b, size_t bucket_key_pos)
+{
+	size_t bucket_id = ((uint8_t *)b - t->buckets) >> t->params.bucket_size_log2;
+
+	return (bucket_id << TABLE_KEYS_PER_BUCKET_LOG2) + bucket_key_pos;
+}
+
 uint64_t
 rte_swx_table_learner_footprint_get(struct rte_swx_table_learner_params *params)
 {
@@ -332,7 +341,7 @@  struct mailbox {
 	/* Writer: lookup state 0. Reader(s): lookup state 1, add(). */
 	uint32_t input_sig;
 
-	/* Writer: lookup state 1. Reader(s): add(). */
+	/* Writer: lookup state 0. Reader(s): lookup state 1, add(). */
 	uint8_t *input_key;
 
 	/* Writer: lookup state 1. Reader(s): add(). Values: 0 = miss; 1 = hit. */
@@ -358,6 +367,7 @@  rte_swx_table_learner_lookup(void *table,
 			     uint8_t **key,
 			     uint64_t *action_id,
 			     uint8_t **action_data,
+			     size_t *entry_id,
 			     int *hit)
 {
 	struct table *t = table;
@@ -412,6 +422,7 @@  rte_swx_table_learner_lookup(void *table,
 
 				*action_id = data[0];
 				*action_data = (uint8_t *)&data[1];
+				*entry_id = table_entry_id_get(t, b, i);
 				*hit = 1;
 				return 1;
 			}
diff --git a/lib/table/rte_swx_table_learner.h b/lib/table/rte_swx_table_learner.h
index d72b6b88ff..62cac3f225 100644
--- a/lib/table/rte_swx_table_learner.h
+++ b/lib/table/rte_swx_table_learner.h
@@ -173,6 +173,14 @@  rte_swx_table_learner_timeout_update(void *table,
  * possibly an associated key add operation. The mailbox mechanism allows for multiple concurrent
  * table key lookup and add operations into the same table.
  *
+ * The table entry consists of the action ID and the action data. Each table entry is unique, even
+ * though different table entries can have identical content, i.e. same values for the action ID and
+ * the action data. The table entry ID is also returned by the table lookup operation. It can be
+ * used to index into an external array of resources such as counters, registers or meters to
+ * identify the resource directly associated with the current table entry with no need to store the
+ * corresponding index into the table entry. The index of the external resource is thus
+ * auto-generated instead of being stored in the table entry.
+ *
  * @param[in] table
  *   Table handle.
  * @param[in] mailbox
@@ -187,6 +195,9 @@  rte_swx_table_learner_timeout_update(void *table,
  * @param[out] action_data
  *   Action data for the *action_id* action. Must point to a valid array of table *action_data_size*
  *   bytes. Only valid when the function returns 1 and *hit* is set to true.
+ * @param[out] entry_id
+ *   Table entry unique ID. Must point to a valid 32-bit variable. Only valid when the function
+ *   returns 1 and *hit* is set to true.
  * @param[out] hit
  *   Only valid when the function returns 1. Set to non-zero (true) on table lookup hit and to zero
  *   (false) on table lookup miss.
@@ -202,6 +213,7 @@  rte_swx_table_learner_lookup(void *table,
 			     uint8_t **key,
 			     uint64_t *action_id,
 			     uint8_t **action_data,
+			     size_t *entry_id,
 			     int *hit);
 
 /**