[dpdk-dev] [PATCH 4/6] cxgbe: Update rx path to receive jumbo frames

[Rahul Lakkireddy <rahul.lakkireddy@chelsio.com>]

Ensure jumbo mode is enabled and that the mbuf data room size can
accommodate jumbo size.  If the mbuf data room size can't accommodate
jumbo size, chain mbufs to jumbo size.

Signed-off-by: Rahul Lakkireddy <rahul.lakkireddy@chelsio.com>
Signed-off-by: Kumar Sanghvi <kumaras@chelsio.com>
---
 drivers/net/cxgbe/sge.c | 58 ++++++++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 53 insertions(+), 5 deletions(-)

diff --git a/drivers/net/cxgbe/sge.c b/drivers/net/cxgbe/sge.c
index 921173a..91ef363 100644
--- a/drivers/net/cxgbe/sge.c
+++ b/drivers/net/cxgbe/sge.c
@@ -247,6 +247,29 @@ static inline bool fl_starving(const struct adapter *adapter,
 	return fl->avail - fl->pend_cred <= s->fl_starve_thres;
 }
 
+static inline unsigned int get_buf_size(struct adapter *adapter,
+					const struct rx_sw_desc *d)
+{
+	unsigned int rx_buf_size_idx = d->dma_addr & RX_BUF_SIZE;
+	unsigned int buf_size = 0;
+
+	switch (rx_buf_size_idx) {
+	case RX_SMALL_MTU_BUF:
+		buf_size = FL_MTU_SMALL_BUFSIZE(adapter);
+		break;
+
+	case RX_LARGE_MTU_BUF:
+		buf_size = FL_MTU_LARGE_BUFSIZE(adapter);
+		break;
+
+	default:
+		BUG_ON(1);
+		/* NOT REACHED */
+	}
+
+	return buf_size;
+}
+
 /**
  * free_rx_bufs - free the Rx buffers on an SGE free list
  * @q: the SGE free list to free buffers from
@@ -362,6 +385,14 @@ static unsigned int refill_fl_usembufs(struct adapter *adap, struct sge_fl *q,
 	unsigned int buf_size_idx = RX_SMALL_MTU_BUF;
 	struct rte_mbuf *buf_bulk[n];
 	int ret, i;
+	struct rte_pktmbuf_pool_private *mbp_priv;
+	u8 jumbo_en = rxq->rspq.eth_dev->data->dev_conf.rxmode.jumbo_frame;
+
+	/* Use jumbo mtu buffers iff mbuf data room size can fit jumbo data. */
+	mbp_priv = rte_mempool_get_priv(rxq->rspq.mb_pool);
+	if (jumbo_en &&
+	    ((mbp_priv->mbuf_data_room_size - RTE_PKTMBUF_HEADROOM) >= 9000))
+		buf_size_idx = RX_LARGE_MTU_BUF;
 
 	ret = rte_mempool_get_bulk(rxq->rspq.mb_pool, (void *)buf_bulk, n);
 	if (unlikely(ret != 0)) {
@@ -1439,14 +1470,31 @@ static int process_responses(struct sge_rspq *q, int budget,
 			const struct cpl_rx_pkt *cpl =
 						(const void *)&q->cur_desc[1];
 			bool csum_ok = cpl->csum_calc && !cpl->err_vec;
-			struct rte_mbuf *pkt;
-			u32 len = ntohl(rc->pldbuflen_qid);
+			struct rte_mbuf *pkt, *npkt;
+			u32 len, bufsz;
 
+			len = ntohl(rc->pldbuflen_qid);
 			BUG_ON(!(len & F_RSPD_NEWBUF));
 			pkt = rsd->buf;
-			pkt->data_len = G_RSPD_LEN(len);
-			pkt->pkt_len = pkt->data_len;
-			unmap_rx_buf(&rxq->fl);
+			npkt = pkt;
+			len = G_RSPD_LEN(len);
+			pkt->pkt_len = len;
+
+			/* Chain mbufs into len if necessary */
+			while (len) {
+				struct rte_mbuf *new_pkt = rsd->buf;
+
+				bufsz = min(get_buf_size(q->adapter, rsd), len);
+				new_pkt->data_len = bufsz;
+				unmap_rx_buf(&rxq->fl);
+				len -= bufsz;
+				npkt->next = new_pkt;
+				npkt = new_pkt;
+				pkt->nb_segs++;
+				rsd = &rxq->fl.sdesc[rxq->fl.cidx];
+			}
+			npkt->next = NULL;
+			pkt->nb_segs--;
 
 			if (cpl->l2info & htonl(F_RXF_IP)) {
 				pkt->packet_type = RTE_PTYPE_L3_IPV4;
-- 
2.5.3