[PATCH v8 5/5] net/dpaa2: enable software taildrop for ordered queues

[Gagandeep Singh]

This patch adds support for software taildrop on ordered queues
in the DPAA2 driver.
It also enables congestion notification by default on
traffic management (TM) queues,  which is a prerequisite for
software taildrop functionality.

Signed-off-by: Gagandeep Singh <g.singh at nxp.com>
---
 doc/guides/rel_notes/release_25_07.rst |  3 ++
 drivers/net/dpaa2/dpaa2_rxtx.c         | 18 +++++++-
 drivers/net/dpaa2/dpaa2_tm.c           | 60 +++++++++++++-------------
 3 files changed, 49 insertions(+), 32 deletions(-)

diff --git a/doc/guides/rel_notes/release_25_07.rst b/doc/guides/rel_notes/release_25_07.rst
index b75405edf6..8fdc27338a 100644
--- a/doc/guides/rel_notes/release_25_07.rst
+++ b/doc/guides/rel_notes/release_25_07.rst
@@ -160,6 +160,9 @@ New Features
   (including out-of-tree nodes).
   This minimizes footprint of node specific mbuf dynamic field.
 
+* **Updated DPAA2 ethernet driver.**
+
+  * Enabled software taildrop for ordered queues.
 
 Removed Items
 -------------
diff --git a/drivers/net/dpaa2/dpaa2_rxtx.c b/drivers/net/dpaa2/dpaa2_rxtx.c
index 67d065bb7c..5bd377d4e6 100644
--- a/drivers/net/dpaa2/dpaa2_rxtx.c
+++ b/drivers/net/dpaa2/dpaa2_rxtx.c
@@ -1800,8 +1800,11 @@ dpaa2_dev_tx_ordered(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
 		while (qbman_result_SCN_state(dpaa2_q->cscn)) {
 			retry_count++;
 			/* Retry for some time before giving up */
-			if (retry_count > CONG_RETRY_COUNT)
+			if (retry_count > CONG_RETRY_COUNT) {
+				if (dpaa2_q->tm_sw_td)
+					goto sw_td;
 				goto skip_tx;
+			}
 		}
 
 		frames_to_send = (nb_pkts > dpaa2_eqcr_size) ?
@@ -1961,6 +1964,19 @@ dpaa2_dev_tx_ordered(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
 			rte_pktmbuf_free_seg(buf_to_free[loop].seg);
 	}
 
+	return num_tx;
+sw_td:
+	for (loop = 0; loop < free_count; loop++) {
+		if (buf_to_free[loop].pkt_id < num_tx)
+			rte_pktmbuf_free_seg(buf_to_free[loop].seg);
+	}
+
+	/* free the pending buffers */
+	rte_pktmbuf_free_bulk(bufs, nb_pkts);
+
+	num_tx += nb_pkts;
+	dpaa2_q->tx_pkts += num_tx;
+
 	return num_tx;
 }
 
diff --git a/drivers/net/dpaa2/dpaa2_tm.c b/drivers/net/dpaa2/dpaa2_tm.c
index dbf66c756e..36e815c356 100644
--- a/drivers/net/dpaa2/dpaa2_tm.c
+++ b/drivers/net/dpaa2/dpaa2_tm.c
@@ -611,41 +611,39 @@ dpaa2_tm_configure_queue(struct rte_eth_dev *dev, struct dpaa2_tm_node *node)
 	}
 	dpaa2_q->fqid = qid.fqid;
 
-	/* setting congestion notification */
-	if (!(priv->flags & DPAA2_TX_CGR_OFF)) {
-		struct dpni_congestion_notification_cfg cong_notif_cfg = {0};
-
-		cong_notif_cfg.units = DPNI_CONGESTION_UNIT_FRAMES;
-		cong_notif_cfg.threshold_entry = dpaa2_q->nb_desc;
-		/* Notify that the queue is not congested when the data in
-		 * the queue is below this thershold.(90% of value)
-		 */
-		cong_notif_cfg.threshold_exit = (dpaa2_q->nb_desc * 9) / 10;
-		cong_notif_cfg.message_ctx = 0;
-		iova = DPAA2_VADDR_TO_IOVA_AND_CHECK(dpaa2_q->cscn,
-				sizeof(struct qbman_result));
-		if (iova == RTE_BAD_IOVA) {
-			DPAA2_PMD_ERR("No IOMMU map for cscn(%p)", dpaa2_q->cscn);
-			return -ENOBUFS;
-		}
-		cong_notif_cfg.message_iova = iova;
-		cong_notif_cfg.dest_cfg.dest_type = DPNI_DEST_NONE;
-		cong_notif_cfg.notification_mode =
+	/* setting taildrop through congestion notification */
+	struct dpni_congestion_notification_cfg cong_notif_cfg = {0};
+
+	cong_notif_cfg.units = DPNI_CONGESTION_UNIT_FRAMES;
+	cong_notif_cfg.threshold_entry = dpaa2_q->nb_desc;
+	/* Notify that the queue is not congested when the data in
+	 * the queue is below this thershold.(90% of value)
+	 */
+	cong_notif_cfg.threshold_exit = (dpaa2_q->nb_desc * 9) / 10;
+	cong_notif_cfg.message_ctx = 0;
+
+	iova = DPAA2_VADDR_TO_IOVA_AND_CHECK(dpaa2_q->cscn,
+			sizeof(struct qbman_result));
+	if (iova == RTE_BAD_IOVA) {
+		DPAA2_PMD_ERR("No IOMMU map for cscn(%p)", dpaa2_q->cscn);
+		return -ENOBUFS;
+	}
+	cong_notif_cfg.message_iova = iova;
+	cong_notif_cfg.dest_cfg.dest_type = DPNI_DEST_NONE;
+	cong_notif_cfg.notification_mode =
 					DPNI_CONG_OPT_WRITE_MEM_ON_ENTER |
 					DPNI_CONG_OPT_WRITE_MEM_ON_EXIT |
 					DPNI_CONG_OPT_COHERENT_WRITE;
-		cong_notif_cfg.cg_point = DPNI_CP_QUEUE;
+	cong_notif_cfg.cg_point = DPNI_CP_QUEUE;
 
-		ret = dpni_set_congestion_notification(dpni, CMD_PRI_LOW,
-					priv->token,
-					DPNI_QUEUE_TX,
-					((node->parent->channel_id << 8) | tc_id),
-					&cong_notif_cfg);
-		if (ret) {
-			DPAA2_PMD_ERR("Error in setting tx congestion notification: "
-				"err=%d", ret);
-			return -ret;
-		}
+	ret = dpni_set_congestion_notification(dpni, CMD_PRI_LOW,
+			priv->token, DPNI_QUEUE_TX,
+			((node->parent->channel_id << 8) | tc_id),
+			&cong_notif_cfg);
+	if (ret) {
+		DPAA2_PMD_ERR("Error in setting tx congestion notification: "
+			"err=%d", ret);
+		return -ret;
 	}
 	dpaa2_q->tm_sw_td = true;
 
-- 
2.25.1