[dpdk-dev] [PATCH v3 15/27] net/ena: linearize Tx mbuf

[Michal Krawczyk <mk@semihalf.com>]

From: Rafal Kozik <rk@semihalf.com>

Function ena_check_and_linearize_mbuf check Tx mbuf for number of
segments and linearize (defragment) it if necessary. It is called
before sending each packet.

Information about maximum number of segments is stored per each ring.

Maximum number of segments supported by NIC is taken from ENA COM in
ena_calc_queue_size function and stored in adapter structure.

Signed-off-by: Rafal Kozik <rk@semihalf.com>
Acked-by: Michal Krawczyk <mk@semihalf.com>
---
 drivers/net/ena/ena_ethdev.c | 31 ++++++++++++++++++++++++++++++-
 drivers/net/ena/ena_ethdev.h |  2 ++
 2 files changed, 32 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ena/ena_ethdev.c b/drivers/net/ena/ena_ethdev.c
index f0e95ef58..cdefcd325 100644
--- a/drivers/net/ena/ena_ethdev.c
+++ b/drivers/net/ena/ena_ethdev.c
@@ -894,6 +894,7 @@ static int ena_check_valid_conf(struct ena_adapter *adapter)
 
 static int
 ena_calc_queue_size(struct ena_com_dev *ena_dev,
+		    u16 *max_tx_sgl_size,
 		    struct ena_com_dev_get_features_ctx *get_feat_ctx)
 {
 	uint32_t queue_size = ENA_DEFAULT_RING_SIZE;
@@ -916,6 +917,9 @@ ena_calc_queue_size(struct ena_com_dev *ena_dev,
 		return -EFAULT;
 	}
 
+	*max_tx_sgl_size = RTE_MIN(ENA_PKT_MAX_BUFS,
+		get_feat_ctx->max_queues.max_packet_tx_descs);
+
 	return queue_size;
 }
 
@@ -1491,6 +1495,7 @@ static int eth_ena_dev_init(struct rte_eth_dev *eth_dev)
 	struct ena_com_dev *ena_dev = &adapter->ena_dev;
 	struct ena_com_dev_get_features_ctx get_feat_ctx;
 	int queue_size, rc;
+	u16 tx_sgl_size = 0;
 
 	static int adapters_found;
 	bool wd_state;
@@ -1547,13 +1552,15 @@ static int eth_ena_dev_init(struct rte_eth_dev *eth_dev)
 	ena_dev->tx_mem_queue_type = ENA_ADMIN_PLACEMENT_POLICY_HOST;
 	adapter->num_queues = get_feat_ctx.max_queues.max_sq_num;
 
-	queue_size = ena_calc_queue_size(ena_dev, &get_feat_ctx);
+	queue_size = ena_calc_queue_size(ena_dev, &tx_sgl_size, &get_feat_ctx);
 	if ((queue_size <= 0) || (adapter->num_queues <= 0))
 		return -EFAULT;
 
 	adapter->tx_ring_size = queue_size;
 	adapter->rx_ring_size = queue_size;
 
+	adapter->max_tx_sgl_size = tx_sgl_size;
+
 	/* prepare ring structures */
 	ena_init_rings(adapter);
 
@@ -1652,6 +1659,7 @@ static void ena_init_rings(struct ena_adapter *adapter)
 		ring->id = i;
 		ring->tx_mem_queue_type = adapter->ena_dev.tx_mem_queue_type;
 		ring->tx_max_header_size = adapter->ena_dev.tx_max_header_size;
+		ring->sgl_size = adapter->max_tx_sgl_size;
 	}
 
 	for (i = 0; i < adapter->num_queues; i++) {
@@ -1923,6 +1931,23 @@ static void ena_update_hints(struct ena_adapter *adapter,
 	}
 }
 
+static int ena_check_and_linearize_mbuf(struct ena_ring *tx_ring,
+					struct rte_mbuf *mbuf)
+{
+	int num_segments, rc;
+
+	num_segments = mbuf->nb_segs;
+
+	if (likely(num_segments < tx_ring->sgl_size))
+		return 0;
+
+	rc = rte_pktmbuf_linearize(mbuf);
+	if (unlikely(rc))
+		RTE_LOG(WARNING, PMD, "Mbuf linearize failed\n");
+
+	return rc;
+}
+
 static uint16_t eth_ena_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
 				  uint16_t nb_pkts)
 {
@@ -1953,6 +1978,10 @@ static uint16_t eth_ena_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
 	for (sent_idx = 0; sent_idx < nb_pkts; sent_idx++) {
 		mbuf = tx_pkts[sent_idx];
 
+		rc = ena_check_and_linearize_mbuf(tx_ring, mbuf);
+		if (unlikely(rc))
+			break;
+
 		req_id = tx_ring->empty_tx_reqs[next_to_use & ring_mask];
 		tx_info = &tx_ring->tx_buffer_info[req_id];
 		tx_info->mbuf = mbuf;
diff --git a/drivers/net/ena/ena_ethdev.h b/drivers/net/ena/ena_ethdev.h
index bba5ad53a..73c110ab9 100644
--- a/drivers/net/ena/ena_ethdev.h
+++ b/drivers/net/ena/ena_ethdev.h
@@ -101,6 +101,7 @@ struct ena_ring {
 	int configured;
 	struct ena_adapter *adapter;
 	uint64_t offloads;
+	u16 sgl_size;
 } __rte_cache_aligned;
 
 enum ena_adapter_state {
@@ -167,6 +168,7 @@ struct ena_adapter {
 	/* TX */
 	struct ena_ring tx_ring[ENA_MAX_NUM_QUEUES] __rte_cache_aligned;
 	int tx_ring_size;
+	u16 max_tx_sgl_size;
 
 	/* RX */
 	struct ena_ring rx_ring[ENA_MAX_NUM_QUEUES] __rte_cache_aligned;
-- 
2.14.1