[PATCH v2 1/3] eventdev: add element offset to event vector

[<pbhagavatula@marvell.com>]

From: Pavan Nikhilesh <pbhagavatula@marvell.com>

Add `rte_event_vector:elem_offset:12` bit field event vector
structure the bits are taken from `rte_event_vector::rsvd:15`.
The element offset defines the offset into the vector array
at which valid elements start.
The valid elements count will be equal to
`rte_event_vector::nb_elem`.

Update Rx/Tx adapter SW implementation to use elem_offset.

Signed-off-by: Pavan Nikhilesh <pbhagavatula@marvell.com>
---
 v2 Changes:
 - Revert changes to definition of `rte_event_vector::nb_elem`

 lib/eventdev/rte_event_eth_rx_adapter.c | 1 +
 lib/eventdev/rte_event_eth_tx_adapter.c | 8 +++++---
 lib/eventdev/rte_eventdev.h             | 6 ++++--
 3 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/lib/eventdev/rte_event_eth_rx_adapter.c b/lib/eventdev/rte_event_eth_rx_adapter.c
index bf8741d2ea..bd72f9b845 100644
--- a/lib/eventdev/rte_event_eth_rx_adapter.c
+++ b/lib/eventdev/rte_event_eth_rx_adapter.c
@@ -855,6 +855,7 @@ rxa_init_vector(struct event_eth_rx_adapter *rx_adapter,
 	vec->vector_ev->port = vec->port;
 	vec->vector_ev->queue = vec->queue;
 	vec->vector_ev->attr_valid = true;
+	vec->vector_ev->elem_offset = 0;
 	TAILQ_INSERT_TAIL(&rx_adapter->vector_list, vec, next);
 }

diff --git a/lib/eventdev/rte_event_eth_tx_adapter.c b/lib/eventdev/rte_event_eth_tx_adapter.c
index b4b37f1cae..ccc7fffcce 100644
--- a/lib/eventdev/rte_event_eth_tx_adapter.c
+++ b/lib/eventdev/rte_event_eth_tx_adapter.c
@@ -524,16 +524,18 @@ txa_process_event_vector(struct txa_service_data *txa,
 		queue = vec->queue;
 		tqi = txa_service_queue(txa, port, queue);
 		if (unlikely(tqi == NULL || !tqi->added)) {
-			rte_pktmbuf_free_bulk(mbufs, vec->nb_elem);
+			rte_pktmbuf_free_bulk(&mbufs[vec->elem_offset],
+					      vec->nb_elem);
 			rte_mempool_put(rte_mempool_from_obj(vec), vec);
 			return 0;
 		}
 		for (i = 0; i < vec->nb_elem; i++) {
 			nb_tx += rte_eth_tx_buffer(port, queue, tqi->tx_buf,
-						   mbufs[i]);
+						   mbufs[i + vec->elem_offset]);
 		}
 	} else {
-		for (i = 0; i < vec->nb_elem; i++) {
+		for (i = vec->elem_offset; i < vec->elem_offset + vec->nb_elem;
+		     i++) {
 			port = mbufs[i]->port;
 			queue = rte_event_eth_tx_adapter_txq_get(mbufs[i]);
 			tqi = txa_service_queue(txa, port, queue);
diff --git a/lib/eventdev/rte_eventdev.h b/lib/eventdev/rte_eventdev.h
index 6a6f6ea4c1..f9fd44604e 100644
--- a/lib/eventdev/rte_eventdev.h
+++ b/lib/eventdev/rte_eventdev.h
@@ -1060,8 +1060,10 @@ rte_event_dev_close(uint8_t dev_id);
  */
 struct rte_event_vector {
 	uint16_t nb_elem;
-	/**< Number of elements in this event vector. */
-	uint16_t rsvd : 15;
+	/**< Number of elements valid in this event vector. */
+	uint16_t elem_offset : 12;
+	/**< Offset into the vector array where valid elements start from. */
+	uint16_t rsvd : 3;
 	/**< Reserved for future use */
 	uint16_t attr_valid : 1;
 	/**< Indicates that the below union attributes have valid information.
--
2.25.1