[dpdk-dev] [PATCH 05/32] net/ngbe: support CRC offload

[Jiawen Wu <jiawenwu@trustnetic.com>]

Support to strip or keep CRC in Rx path.

Signed-off-by: Jiawen Wu <jiawenwu@trustnetic.com>
---
 doc/guides/nics/features/ngbe.ini |  1 +
 drivers/net/ngbe/ngbe_rxtx.c      | 53 +++++++++++++++++++++++++++++--
 drivers/net/ngbe/ngbe_rxtx.h      |  1 +
 3 files changed, 53 insertions(+), 2 deletions(-)

diff --git a/doc/guides/nics/features/ngbe.ini b/doc/guides/nics/features/ngbe.ini
index 32f74a3084..2a472d9434 100644
--- a/doc/guides/nics/features/ngbe.ini
+++ b/doc/guides/nics/features/ngbe.ini
@@ -10,6 +10,7 @@ Link status event    = Y
 Queue start/stop     = Y
 Scattered Rx         = Y
 TSO                  = Y
+CRC offload          = P
 L3 checksum offload  = P
 L4 checksum offload  = P
 Inner L3 checksum    = P
diff --git a/drivers/net/ngbe/ngbe_rxtx.c b/drivers/net/ngbe/ngbe_rxtx.c
index 21f5808787..f9d8cf9d19 100644
--- a/drivers/net/ngbe/ngbe_rxtx.c
+++ b/drivers/net/ngbe/ngbe_rxtx.c
@@ -968,7 +968,8 @@ ngbe_rx_scan_hw_ring(struct ngbe_rx_queue *rxq)
 		/* Translate descriptor info to mbuf format */
 		for (j = 0; j < nb_dd; ++j) {
 			mb = rxep[j].mbuf;
-			pkt_len = rte_le_to_cpu_16(rxdp[j].qw1.hi.len);
+			pkt_len = rte_le_to_cpu_16(rxdp[j].qw1.hi.len) -
+				  rxq->crc_len;
 			mb->data_len = pkt_len;
 			mb->pkt_len = pkt_len;
 
@@ -1271,7 +1272,8 @@ ngbe_recv_pkts(void *rx_queue, struct rte_mbuf **rx_pkts,
 		 *    - IP checksum flag,
 		 *    - error flags.
 		 */
-		pkt_len = (uint16_t)(rte_le_to_cpu_16(rxd.qw1.hi.len));
+		pkt_len = (uint16_t)(rte_le_to_cpu_16(rxd.qw1.hi.len) -
+				      rxq->crc_len);
 		rxm->data_off = RTE_PKTMBUF_HEADROOM;
 		rte_packet_prefetch((char *)rxm->buf_addr + rxm->data_off);
 		rxm->nb_segs = 1;
@@ -1521,6 +1523,22 @@ ngbe_recv_pkts_sc(void *rx_queue, struct rte_mbuf **rx_pkts, uint16_t nb_pkts,
 		/* Initialize the first mbuf of the returned packet */
 		ngbe_fill_cluster_head_buf(first_seg, &rxd, rxq, staterr);
 
+		/* Deal with the case, when HW CRC srip is disabled. */
+		first_seg->pkt_len -= rxq->crc_len;
+		if (unlikely(rxm->data_len <= rxq->crc_len)) {
+			struct rte_mbuf *lp;
+
+			for (lp = first_seg; lp->next != rxm; lp = lp->next)
+				;
+
+			first_seg->nb_segs--;
+			lp->data_len -= rxq->crc_len - rxm->data_len;
+			lp->next = NULL;
+			rte_pktmbuf_free_seg(rxm);
+		} else {
+			rxm->data_len -= rxq->crc_len;
+		}
+
 		/* Prefetch data of first segment, if configured to do so. */
 		rte_packet_prefetch((char *)first_seg->buf_addr +
 			first_seg->data_off);
@@ -1989,6 +2007,7 @@ ngbe_get_rx_port_offloads(struct rte_eth_dev *dev __rte_unused)
 	offloads = DEV_RX_OFFLOAD_IPV4_CKSUM  |
 		   DEV_RX_OFFLOAD_UDP_CKSUM   |
 		   DEV_RX_OFFLOAD_TCP_CKSUM   |
+		   DEV_RX_OFFLOAD_KEEP_CRC    |
 		   DEV_RX_OFFLOAD_SCATTER;
 
 	return offloads;
@@ -2032,6 +2051,10 @@ ngbe_dev_rx_queue_setup(struct rte_eth_dev *dev,
 	rxq->queue_id = queue_idx;
 	rxq->reg_idx = queue_idx;
 	rxq->port_id = dev->data->port_id;
+	if (dev->data->dev_conf.rxmode.offloads & DEV_RX_OFFLOAD_KEEP_CRC)
+		rxq->crc_len = RTE_ETHER_CRC_LEN;
+	else
+		rxq->crc_len = 0;
 	rxq->drop_en = rx_conf->rx_drop_en;
 	rxq->rx_deferred_start = rx_conf->rx_deferred_start;
 	rxq->offloads = offloads;
@@ -2259,6 +2282,7 @@ ngbe_dev_rx_init(struct rte_eth_dev *dev)
 	uint32_t fctrl;
 	uint32_t hlreg0;
 	uint32_t srrctl;
+	uint32_t rdrxctl;
 	uint32_t rxcsum;
 	uint16_t buf_size;
 	uint16_t i;
@@ -2279,7 +2303,14 @@ ngbe_dev_rx_init(struct rte_eth_dev *dev)
 	fctrl |= NGBE_PSRCTL_BCA;
 	wr32(hw, NGBE_PSRCTL, fctrl);
 
+	/*
+	 * Configure CRC stripping, if any.
+	 */
 	hlreg0 = rd32(hw, NGBE_SECRXCTL);
+	if (rx_conf->offloads & DEV_RX_OFFLOAD_KEEP_CRC)
+		hlreg0 &= ~NGBE_SECRXCTL_CRCSTRIP;
+	else
+		hlreg0 |= NGBE_SECRXCTL_CRCSTRIP;
 	hlreg0 &= ~NGBE_SECRXCTL_XDSA;
 	wr32(hw, NGBE_SECRXCTL, hlreg0);
 
@@ -2290,6 +2321,15 @@ ngbe_dev_rx_init(struct rte_eth_dev *dev)
 	for (i = 0; i < dev->data->nb_rx_queues; i++) {
 		rxq = dev->data->rx_queues[i];
 
+		/*
+		 * Reset crc_len in case it was changed after queue setup by a
+		 * call to configure.
+		 */
+		if (rx_conf->offloads & DEV_RX_OFFLOAD_KEEP_CRC)
+			rxq->crc_len = RTE_ETHER_CRC_LEN;
+		else
+			rxq->crc_len = 0;
+
 		/* Setup the Base and Length of the Rx Descriptor Rings */
 		bus_addr = rxq->rx_ring_phys_addr;
 		wr32(hw, NGBE_RXBAL(rxq->reg_idx),
@@ -2334,6 +2374,15 @@ ngbe_dev_rx_init(struct rte_eth_dev *dev)
 
 	wr32(hw, NGBE_PSRCTL, rxcsum);
 
+	if (hw->is_pf) {
+		rdrxctl = rd32(hw, NGBE_SECRXCTL);
+		if (rx_conf->offloads & DEV_RX_OFFLOAD_KEEP_CRC)
+			rdrxctl &= ~NGBE_SECRXCTL_CRCSTRIP;
+		else
+			rdrxctl |= NGBE_SECRXCTL_CRCSTRIP;
+		wr32(hw, NGBE_SECRXCTL, rdrxctl);
+	}
+
 	ngbe_set_rx_function(dev);
 
 	return 0;
diff --git a/drivers/net/ngbe/ngbe_rxtx.h b/drivers/net/ngbe/ngbe_rxtx.h
index 27c83f45a7..07b6e2374e 100644
--- a/drivers/net/ngbe/ngbe_rxtx.h
+++ b/drivers/net/ngbe/ngbe_rxtx.h
@@ -268,6 +268,7 @@ struct ngbe_rx_queue {
 	/** Packet type mask for different NICs */
 	uint16_t        pkt_type_mask;
 	uint16_t        port_id;  /**< Device port identifier */
+	uint8_t         crc_len;  /**< 0 if CRC stripped, 4 otherwise. */
 	uint8_t         drop_en;  /**< If not 0, set SRRCTL.Drop_En */
 	uint8_t         rx_deferred_start; /**< not in global dev start */
 	uint64_t	offloads; /**< Rx offloads with DEV_RX_OFFLOAD_* */
-- 
2.21.0.windows.1