[dpdk-dev] [PATCH v2] net/e1000: correct VLAN tag byte order for i35x LB packets

[Roger B Melton <rmelton@cisco.com>]

When copying VLAN tags from the RX descriptor to the vlan_tci field
in the mbuf header,  igb_rxtx.c:eth_igb_recv_pkts() and
eth_igb_recv_scattered_pkts() both assume that the VLAN tag is always
little endian.  While i350, i354 and /i350vf VLAN non-loopback
packets are stored little endian, VLAN tags in loopback packets for
those devices are big endian.

For i350, i354 and i350vf VLAN loopback packets, swap the tag when
copying from the RX descriptor to the mbuf header.  This will ensure
that the mbuf vlan_tci is always little endian.

Signed-off-by: Roger B Melton <rmelton@cisco.com>
---
v2:
* PF: Limit swap to i350 and i354
* VF: Limit swap to i350VF

 drivers/net/e1000/igb_rxtx.c | 55 ++++++++++++++++++++++++++++++++++++++++----
 1 file changed, 50 insertions(+), 5 deletions(-)

diff --git a/drivers/net/e1000/igb_rxtx.c b/drivers/net/e1000/igb_rxtx.c
index 1c80a2a..3eb547b 100644
--- a/drivers/net/e1000/igb_rxtx.c
+++ b/drivers/net/e1000/igb_rxtx.c
@@ -105,6 +105,13 @@ struct igb_tx_entry {
 };
 
 /**
+ * rx queue flags
+ */
+enum igb_rxq_flags {
+	IGB_RXQ_FLAG_LB_BSWAP_VLAN = 0x01,
+};
+
+/**
  * Structure associated with each RX queue.
  */
 struct igb_rx_queue {
@@ -128,6 +135,7 @@ struct igb_rx_queue {
 	uint8_t             wthresh;    /**< Write-back threshold register. */
 	uint8_t             crc_len;    /**< 0 if CRC stripped, 4 otherwise. */
 	uint8_t             drop_en;  /**< If not 0, set SRRCTL.Drop_En. */
+	uint32_t            flags;      /**< RX flags. */
 };
 
 /**
@@ -946,9 +954,16 @@ eth_igb_recv_pkts(void *rx_queue, struct rte_mbuf **rx_pkts,
 
 		rxm->hash.rss = rxd.wb.lower.hi_dword.rss;
 		hlen_type_rss = rte_le_to_cpu_32(rxd.wb.lower.lo_dword.data);
-		/* Only valid if PKT_RX_VLAN_PKT set in pkt_flags */
-		rxm->vlan_tci = rte_le_to_cpu_16(rxd.wb.upper.vlan);
-
+		/*
+		 * The vlan_tci field is only valid when PKT_RX_VLAN_PKT is
+		 * set in the pkt_flags field and must be in CPU byte order.
+		 */
+		if ((staterr & rte_cpu_to_le_32(E1000_RXDEXT_STATERR_LB)) &&
+			(rxq->flags & IGB_RXQ_FLAG_LB_BSWAP_VLAN)) {
+			rxm->vlan_tci = rte_be_to_cpu_16(rxd.wb.upper.vlan);
+		} else {
+			rxm->vlan_tci = rte_le_to_cpu_16(rxd.wb.upper.vlan);
+		}
 		pkt_flags = rx_desc_hlen_type_rss_to_pkt_flags(rxq, hlen_type_rss);
 		pkt_flags = pkt_flags | rx_desc_status_to_pkt_flags(staterr);
 		pkt_flags = pkt_flags | rx_desc_error_to_pkt_flags(staterr);
@@ -1181,9 +1196,16 @@ eth_igb_recv_scattered_pkts(void *rx_queue, struct rte_mbuf **rx_pkts,
 
 		/*
 		 * The vlan_tci field is only valid when PKT_RX_VLAN_PKT is
-		 * set in the pkt_flags field.
+		 * set in the pkt_flags field and must be in CPU byte order.
 		 */
-		first_seg->vlan_tci = rte_le_to_cpu_16(rxd.wb.upper.vlan);
+		if ((staterr & rte_cpu_to_le_32(E1000_RXDEXT_STATERR_LB)) &&
+			(rxq->flags & IGB_RXQ_FLAG_LB_BSWAP_VLAN)) {
+			first_seg->vlan_tci =
+				rte_be_to_cpu_16(rxd.wb.upper.vlan);
+		} else {
+			first_seg->vlan_tci =
+				rte_le_to_cpu_16(rxd.wb.upper.vlan);
+		}
 		hlen_type_rss = rte_le_to_cpu_32(rxd.wb.lower.lo_dword.data);
 		pkt_flags = rx_desc_hlen_type_rss_to_pkt_flags(rxq, hlen_type_rss);
 		pkt_flags = pkt_flags | rx_desc_status_to_pkt_flags(staterr);
@@ -2278,6 +2300,18 @@ eth_igb_rx_init(struct rte_eth_dev *dev)
 
 		rxq = dev->data->rx_queues[i];
 
+		rxq->flags = 0;
+		/*
+		 * i350 and i354 vlan packets have vlan tags byte swapped.
+		 */
+		if ((hw->mac.type == e1000_i350) ||
+			(hw->mac.type == e1000_i354)) {
+			rxq->flags |= IGB_RXQ_FLAG_LB_BSWAP_VLAN;
+			PMD_INIT_LOG(DEBUG, "IGB rx vlan bswap required");
+		} else {
+			PMD_INIT_LOG(DEBUG, "IGB rx vlan bswap not required");
+		}
+
 		/* Allocate buffers for descriptor rings and set up queue */
 		ret = igb_alloc_rx_queue_mbufs(rxq);
 		if (ret)
@@ -2557,6 +2591,17 @@ eth_igbvf_rx_init(struct rte_eth_dev *dev)
 
 		rxq = dev->data->rx_queues[i];
 
+		rxq->flags = 0;
+		/*
+		 * i350VF LB vlan packets have vlan tags byte swapped.
+		 */
+		if (hw->mac.type == e1000_vfadapt_i350) {
+			rxq->flags |= IGB_RXQ_FLAG_LB_BSWAP_VLAN;
+			PMD_INIT_LOG(DEBUG, "IGB rx vlan bswap required");
+		} else {
+			PMD_INIT_LOG(DEBUG, "IGB rx vlan bswap not required");
+		}
+
 		/* Allocate buffers for descriptor rings and set up queue */
 		ret = igb_alloc_rx_queue_mbufs(rxq);
 		if (ret)
-- 
2.10.3.dirty