[dpdk-dev] [PATCH v2 3/5] szedata2: add handling of scattered packets in TX

[Matej Vido <matejvido@gmail.com>]

TX function modified to handle chained mbufs.

Signed-off-by: Matej Vido <matejvido@gmail.com>
Reviewed-by: Jan Viktorin <viktorin@rehivetech.com>
---
 drivers/net/szedata2/rte_eth_szedata2.c | 108 +++++++++++++++++++++++++++-----
 1 file changed, 91 insertions(+), 17 deletions(-)

diff --git a/drivers/net/szedata2/rte_eth_szedata2.c b/drivers/net/szedata2/rte_eth_szedata2.c
index ddb45e4..e2d6501 100644
--- a/drivers/net/szedata2/rte_eth_szedata2.c
+++ b/drivers/net/szedata2/rte_eth_szedata2.c
@@ -737,7 +737,7 @@ eth_szedata2_tx(void *queue,
 next_packet:
 		mbuf = bufs[nb_pkts - pkt_left];
 
-		pkt_len = mbuf->data_len;
+		pkt_len = mbuf->pkt_len;
 		mbuf_segs = mbuf->nb_segs;
 
 		hwpkt_len = RTE_SZE2_PACKET_HEADER_SIZE_ALIGNED +
@@ -764,9 +764,28 @@ next_packet:
 			/* copy packet from mbuf */
 			tmp_dst = ((uint8_t *)(dst)) +
 				RTE_SZE2_PACKET_HEADER_SIZE_ALIGNED;
-			rte_memcpy(tmp_dst,
-				rte_pktmbuf_mtod(mbuf, const void *),
-				pkt_len);
+			if (likely(mbuf_segs == 1)) {
+				/*
+				 * non-scattered packet,
+				 * transmit from one mbuf
+				 */
+				rte_memcpy(tmp_dst,
+					rte_pktmbuf_mtod(mbuf, const void *),
+					pkt_len);
+			} else {
+				/* scattered packet, transmit from more mbufs */
+				struct rte_mbuf * m = mbuf;
+				while (m) {
+					rte_memcpy(tmp_dst,
+						rte_pktmbuf_mtod(m,
+						const void *),
+						m->data_len);
+					tmp_dst = ((uint8_t *)(tmp_dst)) +
+						m->data_len;
+					m = m->next;
+				}
+			}
+
 
 			dst = ((uint8_t *)dst) + hwpkt_len;
 			unlock_size += hwpkt_len;
@@ -805,19 +824,74 @@ next_packet:
 
 			tmp_dst = ((uint8_t *)(dst)) +
 				RTE_SZE2_PACKET_HEADER_SIZE_ALIGNED;
-			/* copy part of packet to first area */
-			rte_memcpy(tmp_dst,
-				rte_pktmbuf_mtod(mbuf, const void *),
-				write_len);
-
-			if (lck->next)
-				dst = lck->next->start;
-
-			/* copy part of packet to second area */
-			rte_memcpy(dst,
-				(const void *) (rte_pktmbuf_mtod(mbuf,
-						const uint8_t *) +
-				write_len), pkt_len - write_len);
+			if (likely(mbuf_segs == 1)) {
+				/*
+				 * non-scattered packet,
+				 * transmit from one mbuf
+				 */
+				/* copy part of packet to first area */
+				rte_memcpy(tmp_dst,
+					rte_pktmbuf_mtod(mbuf, const void *),
+					write_len);
+
+				if (lck->next)
+					dst = lck->next->start;
+
+				/* copy part of packet to second area */
+				rte_memcpy(dst,
+					(const void *) (rte_pktmbuf_mtod(mbuf,
+							const uint8_t *) +
+					write_len), pkt_len - write_len);
+			} else {
+				/* scattered packet, transmit from more mbufs */
+				struct rte_mbuf * m = mbuf;
+				uint16_t written = 0;
+				uint16_t to_write = 0;
+				bool new_mbuf = true;
+				uint16_t write_off = 0;
+
+				/* copy part of packet to first area */
+				while (m && written < write_len) {
+					to_write = RTE_MIN(m->data_len,
+							write_len - written);
+					rte_memcpy(tmp_dst,
+						rte_pktmbuf_mtod(m,
+							const void *),
+						to_write);
+
+					tmp_dst = ((uint8_t *)(tmp_dst)) +
+						to_write;
+					if (m->data_len <= write_len -
+							written) {
+						m = m->next;
+						new_mbuf = true;
+					} else {
+						new_mbuf = false;
+					}
+					written += to_write;
+				}
+
+				if (lck->next)
+					dst = lck->next->start;
+
+				tmp_dst = dst;
+				written = 0;
+				write_off = new_mbuf ? 0 : to_write;
+
+				/* copy part of packet to second area */
+				while (m && written < pkt_len - write_len) {
+					rte_memcpy(tmp_dst, (const void *)
+						(rte_pktmbuf_mtod(m,
+						uint8_t *) + write_off),
+						m->data_len - write_off);
+
+					tmp_dst = ((uint8_t *)(tmp_dst)) +
+						(m->data_len - write_off);
+					written += m->data_len - write_off;
+					m = m->next;
+					write_off = 0;
+				}
+			}
 
 			dst = ((uint8_t *)dst) + rem_len;
 			unlock_size += hwpkt_len;
-- 
1.9.1