[v5,19/24] net/ngbe: add simple Rx and Tx flow

  Initialize device with the simplest receive and transmit functions.

Signed-off-by: Jiawen Wu <jiawenwu@trustnetic.com>
---
 drivers/net/ngbe/ngbe_ethdev.c |   8 +-
 drivers/net/ngbe/ngbe_ethdev.h |   6 +
 drivers/net/ngbe/ngbe_rxtx.c   | 482 +++++++++++++++++++++++++++++++++
 drivers/net/ngbe/ngbe_rxtx.h   | 110 ++++++++
 4 files changed, 604 insertions(+), 2 deletions(-)
  

On 6/2/21 12:41 PM, Jiawen Wu wrote:
> Initialize device with the simplest receive and transmit functions.

Why Rx and Tx are mixed in one patch? It looks separate code.

> 
> Signed-off-by: Jiawen Wu <jiawenwu@trustnetic.com>
> ---
>   drivers/net/ngbe/ngbe_ethdev.c |   8 +-
>   drivers/net/ngbe/ngbe_ethdev.h |   6 +
>   drivers/net/ngbe/ngbe_rxtx.c   | 482 +++++++++++++++++++++++++++++++++
>   drivers/net/ngbe/ngbe_rxtx.h   | 110 ++++++++
>   4 files changed, 604 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/ngbe/ngbe_ethdev.c b/drivers/net/ngbe/ngbe_ethdev.c
> index 672db88133..4dab920caa 100644
> --- a/drivers/net/ngbe/ngbe_ethdev.c
> +++ b/drivers/net/ngbe/ngbe_ethdev.c
> @@ -109,6 +109,8 @@ eth_ngbe_dev_init(struct rte_eth_dev *eth_dev, void *init_params __rte_unused)
>   	PMD_INIT_FUNC_TRACE();
>   
>   	eth_dev->dev_ops = &ngbe_eth_dev_ops;
> +	eth_dev->rx_pkt_burst = &ngbe_recv_pkts;
> +	eth_dev->tx_pkt_burst = &ngbe_xmit_pkts_simple;
>   
>   	if (rte_eal_process_type() != RTE_PROC_PRIMARY)
>   		return 0;
> @@ -357,8 +359,10 @@ ngbe_dev_info_get(struct rte_eth_dev *dev, struct rte_eth_dev_info *dev_info)
>   const uint32_t *
>   ngbe_dev_supported_ptypes_get(struct rte_eth_dev *dev)
>   {
> -	RTE_SET_USED(dev);
> -	return ngbe_get_supported_ptypes();
> +	if (dev->rx_pkt_burst == ngbe_recv_pkts)
> +		return ngbe_get_supported_ptypes();
> +
> +	return NULL;
>   }
>   
>   /* return 0 means link status changed, -1 means not changed */
> diff --git a/drivers/net/ngbe/ngbe_ethdev.h b/drivers/net/ngbe/ngbe_ethdev.h
> index 6881351252..c0f8483eca 100644
> --- a/drivers/net/ngbe/ngbe_ethdev.h
> +++ b/drivers/net/ngbe/ngbe_ethdev.h
> @@ -75,6 +75,12 @@ int ngbe_dev_rx_init(struct rte_eth_dev *dev);
>   
>   void ngbe_dev_tx_init(struct rte_eth_dev *dev);
>   
> +uint16_t ngbe_recv_pkts(void *rx_queue, struct rte_mbuf **rx_pkts,
> +		uint16_t nb_pkts);
> +
> +uint16_t ngbe_xmit_pkts_simple(void *tx_queue, struct rte_mbuf **tx_pkts,
> +		uint16_t nb_pkts);
> +
>   int
>   ngbe_dev_link_update_share(struct rte_eth_dev *dev,
>   		int wait_to_complete);
> diff --git a/drivers/net/ngbe/ngbe_rxtx.c b/drivers/net/ngbe/ngbe_rxtx.c
> index 68d7e651af..9462da5b7a 100644
> --- a/drivers/net/ngbe/ngbe_rxtx.c
> +++ b/drivers/net/ngbe/ngbe_rxtx.c
> @@ -15,10 +15,492 @@
>   #include "ngbe_ethdev.h"
>   #include "ngbe_rxtx.h"
>   
> +/*
> + * Prefetch a cache line into all cache levels.
> + */
> +#define rte_ngbe_prefetch(p)   rte_prefetch0(p)
> +
> +/*********************************************************************
> + *
> + *  TX functions

TX -> Tx

> + *
> + **********************************************************************/
> +
> +/*
> + * Check for descriptors with their DD bit set and free mbufs.
> + * Return the total number of buffers freed.
> + */
> +static __rte_always_inline int
> +ngbe_tx_free_bufs(struct ngbe_tx_queue *txq)
> +{
> +	struct ngbe_tx_entry *txep;
> +	uint32_t status;
> +	int i, nb_free = 0;
> +	struct rte_mbuf *m, *free[RTE_NGBE_TX_MAX_FREE_BUF_SZ];
> +
> +	/* check DD bit on threshold descriptor */
> +	status = txq->tx_ring[txq->tx_next_dd].dw3;
> +	if (!(status & rte_cpu_to_le_32(NGBE_TXD_DD))) {
> +		if (txq->nb_tx_free >> 1 < txq->tx_free_thresh)
> +			ngbe_set32_masked(txq->tdc_reg_addr,
> +				NGBE_TXCFG_FLUSH, NGBE_TXCFG_FLUSH);
> +		return 0;
> +	}
> +
> +	/*
> +	 * first buffer to free from S/W ring is at index
> +	 * tx_next_dd - (tx_free_thresh-1)
> +	 */
> +	txep = &txq->sw_ring[txq->tx_next_dd - (txq->tx_free_thresh - 1)];
> +	for (i = 0; i < txq->tx_free_thresh; ++i, ++txep) {
> +		/* free buffers one at a time */
> +		m = rte_pktmbuf_prefree_seg(txep->mbuf);
> +		txep->mbuf = NULL;
> +
> +		if (unlikely(m == NULL))
> +			continue;
> +
> +		if (nb_free >= RTE_NGBE_TX_MAX_FREE_BUF_SZ ||
> +		    (nb_free > 0 && m->pool != free[0]->pool)) {
> +			rte_mempool_put_bulk(free[0]->pool,
> +					     (void **)free, nb_free);
> +			nb_free = 0;
> +		}
> +
> +		free[nb_free++] = m;
> +	}
> +
> +	if (nb_free > 0)
> +		rte_mempool_put_bulk(free[0]->pool, (void **)free, nb_free);
> +
> +	/* buffers were freed, update counters */
> +	txq->nb_tx_free = (uint16_t)(txq->nb_tx_free + txq->tx_free_thresh);
> +	txq->tx_next_dd = (uint16_t)(txq->tx_next_dd + txq->tx_free_thresh);
> +	if (txq->tx_next_dd >= txq->nb_tx_desc)
> +		txq->tx_next_dd = (uint16_t)(txq->tx_free_thresh - 1);
> +
> +	return txq->tx_free_thresh;
> +}
> +
> +/* Populate 4 descriptors with data from 4 mbufs */
> +static inline void
> +tx4(volatile struct ngbe_tx_desc *txdp, struct rte_mbuf **pkts)
> +{
> +	uint64_t buf_dma_addr;
> +	uint32_t pkt_len;
> +	int i;
> +
> +	for (i = 0; i < 4; ++i, ++txdp, ++pkts) {
> +		buf_dma_addr = rte_mbuf_data_iova(*pkts);
> +		pkt_len = (*pkts)->data_len;
> +
> +		/* write data to descriptor */
> +		txdp->qw0 = rte_cpu_to_le_64(buf_dma_addr);
> +		txdp->dw2 = cpu_to_le32(NGBE_TXD_FLAGS |
> +					NGBE_TXD_DATLEN(pkt_len));
> +		txdp->dw3 = cpu_to_le32(NGBE_TXD_PAYLEN(pkt_len));
> +
> +		rte_prefetch0(&(*pkts)->pool);
> +	}
> +}
> +
> +/* Populate 1 descriptor with data from 1 mbuf */
> +static inline void
> +tx1(volatile struct ngbe_tx_desc *txdp, struct rte_mbuf **pkts)
> +{
> +	uint64_t buf_dma_addr;
> +	uint32_t pkt_len;
> +
> +	buf_dma_addr = rte_mbuf_data_iova(*pkts);
> +	pkt_len = (*pkts)->data_len;
> +
> +	/* write data to descriptor */
> +	txdp->qw0 = cpu_to_le64(buf_dma_addr);
> +	txdp->dw2 = cpu_to_le32(NGBE_TXD_FLAGS |
> +				NGBE_TXD_DATLEN(pkt_len));
> +	txdp->dw3 = cpu_to_le32(NGBE_TXD_PAYLEN(pkt_len));
> +
> +	rte_prefetch0(&(*pkts)->pool);
> +}
> +
> +/*
> + * Fill H/W descriptor ring with mbuf data.
> + * Copy mbuf pointers to the S/W ring.
> + */
> +static inline void
> +ngbe_tx_fill_hw_ring(struct ngbe_tx_queue *txq, struct rte_mbuf **pkts,
> +		      uint16_t nb_pkts)
> +{
> +	volatile struct ngbe_tx_desc *txdp = &txq->tx_ring[txq->tx_tail];
> +	struct ngbe_tx_entry *txep = &txq->sw_ring[txq->tx_tail];
> +	const int N_PER_LOOP = 4;
> +	const int N_PER_LOOP_MASK = N_PER_LOOP - 1;
> +	int mainpart, leftover;
> +	int i, j;
> +
> +	/*
> +	 * Process most of the packets in chunks of N pkts.  Any
> +	 * leftover packets will get processed one at a time.
> +	 */
> +	mainpart = (nb_pkts & ((uint32_t)~N_PER_LOOP_MASK));
> +	leftover = (nb_pkts & ((uint32_t)N_PER_LOOP_MASK));
> +	for (i = 0; i < mainpart; i += N_PER_LOOP) {
> +		/* Copy N mbuf pointers to the S/W ring */
> +		for (j = 0; j < N_PER_LOOP; ++j)
> +			(txep + i + j)->mbuf = *(pkts + i + j);
> +		tx4(txdp + i, pkts + i);
> +	}
> +
> +	if (unlikely(leftover > 0)) {
> +		for (i = 0; i < leftover; ++i) {
> +			(txep + mainpart + i)->mbuf = *(pkts + mainpart + i);
> +			tx1(txdp + mainpart + i, pkts + mainpart + i);
> +		}
> +	}
> +}
> +
> +static inline uint16_t
> +tx_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
> +	     uint16_t nb_pkts)
> +{
> +	struct ngbe_tx_queue *txq = (struct ngbe_tx_queue *)tx_queue;
> +	uint16_t n = 0;
> +
> +	/*
> +	 * Begin scanning the H/W ring for done descriptors when the
> +	 * number of available descriptors drops below tx_free_thresh.  For
> +	 * each done descriptor, free the associated buffer.
> +	 */
> +	if (txq->nb_tx_free < txq->tx_free_thresh)
> +		ngbe_tx_free_bufs(txq);
> +
> +	/* Only use descriptors that are available */
> +	nb_pkts = (uint16_t)RTE_MIN(txq->nb_tx_free, nb_pkts);
> +	if (unlikely(nb_pkts == 0))
> +		return 0;
> +
> +	/* Use exactly nb_pkts descriptors */
> +	txq->nb_tx_free = (uint16_t)(txq->nb_tx_free - nb_pkts);
> +
> +	/*
> +	 * At this point, we know there are enough descriptors in the
> +	 * ring to transmit all the packets.  This assumes that each
> +	 * mbuf contains a single segment, and that no new offloads
> +	 * are expected, which would require a new context descriptor.
> +	 */
> +
> +	/*
> +	 * See if we're going to wrap-around. If so, handle the top
> +	 * of the descriptor ring first, then do the bottom.  If not,
> +	 * the processing looks just like the "bottom" part anyway...
> +	 */
> +	if ((txq->tx_tail + nb_pkts) > txq->nb_tx_desc) {
> +		n = (uint16_t)(txq->nb_tx_desc - txq->tx_tail);
> +		ngbe_tx_fill_hw_ring(txq, tx_pkts, n);
> +		txq->tx_tail = 0;
> +	}
> +
> +	/* Fill H/W descriptor ring with mbuf data */
> +	ngbe_tx_fill_hw_ring(txq, tx_pkts + n, (uint16_t)(nb_pkts - n));
> +	txq->tx_tail = (uint16_t)(txq->tx_tail + (nb_pkts - n));
> +
> +	/*
> +	 * Check for wrap-around. This would only happen if we used
> +	 * up to the last descriptor in the ring, no more, no less.
> +	 */
> +	if (txq->tx_tail >= txq->nb_tx_desc)
> +		txq->tx_tail = 0;
> +
> +	PMD_TX_LOG(DEBUG, "port_id=%u queue_id=%u tx_tail=%u nb_tx=%u",
> +		   (uint16_t)txq->port_id, (uint16_t)txq->queue_id,
> +		   (uint16_t)txq->tx_tail, (uint16_t)nb_pkts);
> +
> +	/* update tail pointer */
> +	rte_wmb();
> +	ngbe_set32_relaxed(txq->tdt_reg_addr, txq->tx_tail);
> +
> +	return nb_pkts;
> +}
> +
> +uint16_t
> +ngbe_xmit_pkts_simple(void *tx_queue, struct rte_mbuf **tx_pkts,
> +		       uint16_t nb_pkts)
> +{
> +	uint16_t nb_tx;
> +
> +	/* Try to transmit at least chunks of TX_MAX_BURST pkts */
> +	if (likely(nb_pkts <= RTE_PMD_NGBE_TX_MAX_BURST))
> +		return tx_xmit_pkts(tx_queue, tx_pkts, nb_pkts);
> +
> +	/* transmit more than the max burst, in chunks of TX_MAX_BURST */
> +	nb_tx = 0;
> +	while (nb_pkts) {
> +		uint16_t ret, n;
> +
> +		n = (uint16_t)RTE_MIN(nb_pkts, RTE_PMD_NGBE_TX_MAX_BURST);
> +		ret = tx_xmit_pkts(tx_queue, &tx_pkts[nb_tx], n);
> +		nb_tx = (uint16_t)(nb_tx + ret);
> +		nb_pkts = (uint16_t)(nb_pkts - ret);
> +		if (ret < n)
> +			break;
> +	}
> +
> +	return nb_tx;
> +}
> +
>   #ifndef DEFAULT_TX_FREE_THRESH
>   #define DEFAULT_TX_FREE_THRESH 32
>   #endif
>   
> +/*********************************************************************
> + *
> + *  RX functions

RX -> Rx

> + *
> + **********************************************************************/
> +static inline uint32_t
> +ngbe_rxd_pkt_info_to_pkt_type(uint32_t pkt_info, uint16_t ptid_mask)
> +{
> +	uint16_t ptid = NGBE_RXD_PTID(pkt_info);
> +
> +	ptid &= ptid_mask;
> +
> +	return ngbe_decode_ptype(ptid);
> +}
> +
> +static inline uint64_t
> +ngbe_rxd_pkt_info_to_pkt_flags(uint32_t pkt_info)
> +{
> +	static uint64_t ip_rss_types_map[16] __rte_cache_aligned = {
> +		0, PKT_RX_RSS_HASH, PKT_RX_RSS_HASH, PKT_RX_RSS_HASH,
> +		0, PKT_RX_RSS_HASH, 0, PKT_RX_RSS_HASH,
> +		PKT_RX_RSS_HASH, 0, 0, 0,
> +		0, 0, 0,  PKT_RX_FDIR,
> +	};
> +	return ip_rss_types_map[NGBE_RXD_RSSTYPE(pkt_info)];
> +}
> +
> +static inline uint64_t
> +rx_desc_status_to_pkt_flags(uint32_t rx_status, uint64_t vlan_flags)
> +{
> +	uint64_t pkt_flags;
> +
> +	/*
> +	 * Check if VLAN present only.
> +	 * Do not check whether L3/L4 rx checksum done by NIC or not,
> +	 * That can be found from rte_eth_rxmode.offloads flag
> +	 */
> +	pkt_flags = (rx_status & NGBE_RXD_STAT_VLAN &&
> +		     vlan_flags & PKT_RX_VLAN_STRIPPED)
> +		    ? vlan_flags : 0;
> +
> +	return pkt_flags;
> +}
> +
> +static inline uint64_t
> +rx_desc_error_to_pkt_flags(uint32_t rx_status)
> +{
> +	uint64_t pkt_flags = 0;
> +
> +	/* checksum offload can't be disabled */
> +	if (rx_status & NGBE_RXD_STAT_IPCS) {
> +		pkt_flags |= (rx_status & NGBE_RXD_ERR_IPCS
> +				? PKT_RX_IP_CKSUM_BAD : PKT_RX_IP_CKSUM_GOOD);
> +	}
> +
> +	if (rx_status & NGBE_RXD_STAT_L4CS) {
> +		pkt_flags |= (rx_status & NGBE_RXD_ERR_L4CS
> +				? PKT_RX_L4_CKSUM_BAD : PKT_RX_L4_CKSUM_GOOD);
> +	}
> +
> +	if (rx_status & NGBE_RXD_STAT_EIPCS &&
> +	    rx_status & NGBE_RXD_ERR_EIPCS) {
> +		pkt_flags |= PKT_RX_OUTER_IP_CKSUM_BAD;
> +	}
> +
> +
> +	return pkt_flags;
> +}
> +
> +uint16_t
> +ngbe_recv_pkts(void *rx_queue, struct rte_mbuf **rx_pkts,
> +		uint16_t nb_pkts)
> +{
> +	struct ngbe_rx_queue *rxq;
> +	volatile struct ngbe_rx_desc *rx_ring;
> +	volatile struct ngbe_rx_desc *rxdp;
> +	struct ngbe_rx_entry *sw_ring;
> +	struct ngbe_rx_entry *rxe;
> +	struct rte_mbuf *rxm;
> +	struct rte_mbuf *nmb;
> +	struct ngbe_rx_desc rxd;
> +	uint64_t dma_addr;
> +	uint32_t staterr;
> +	uint32_t pkt_info;
> +	uint16_t pkt_len;
> +	uint16_t rx_id;
> +	uint16_t nb_rx;
> +	uint16_t nb_hold;
> +	uint64_t pkt_flags;
> +
> +	nb_rx = 0;
> +	nb_hold = 0;
> +	rxq = rx_queue;
> +	rx_id = rxq->rx_tail;
> +	rx_ring = rxq->rx_ring;
> +	sw_ring = rxq->sw_ring;
> +	struct rte_eth_dev *dev = &rte_eth_devices[rxq->port_id];
> +	while (nb_rx < nb_pkts) {
> +		/*
> +		 * The order of operations here is important as the DD status
> +		 * bit must not be read after any other descriptor fields.
> +		 * rx_ring and rxdp are pointing to volatile data so the order
> +		 * of accesses cannot be reordered by the compiler. If they were
> +		 * not volatile, they could be reordered which could lead to
> +		 * using invalid descriptor fields when read from rxd.
> +		 */
> +		rxdp = &rx_ring[rx_id];
> +		staterr = rxdp->qw1.lo.status;
> +		if (!(staterr & rte_cpu_to_le_32(NGBE_RXD_STAT_DD)))
> +			break;
> +		rxd = *rxdp;
> +
> +		/*
> +		 * End of packet.
> +		 *
> +		 * If the NGBE_RXD_STAT_EOP flag is not set, the RX packet
> +		 * is likely to be invalid and to be dropped by the various
> +		 * validation checks performed by the network stack.
> +		 *
> +		 * Allocate a new mbuf to replenish the RX ring descriptor.
> +		 * If the allocation fails:
> +		 *    - arrange for that RX descriptor to be the first one
> +		 *      being parsed the next time the receive function is
> +		 *      invoked [on the same queue].
> +		 *
> +		 *    - Stop parsing the RX ring and return immediately.
> +		 *
> +		 * This policy do not drop the packet received in the RX
> +		 * descriptor for which the allocation of a new mbuf failed.
> +		 * Thus, it allows that packet to be later retrieved if
> +		 * mbuf have been freed in the mean time.
> +		 * As a side effect, holding RX descriptors instead of
> +		 * systematically giving them back to the NIC may lead to
> +		 * RX ring exhaustion situations.
> +		 * However, the NIC can gracefully prevent such situations
> +		 * to happen by sending specific "back-pressure" flow control
> +		 * frames to its peer(s).
> +		 */
> +		PMD_RX_LOG(DEBUG, "port_id=%u queue_id=%u rx_id=%u "
> +			   "ext_err_stat=0x%08x pkt_len=%u",
> +			   (uint16_t)rxq->port_id, (uint16_t)rxq->queue_id,
> +			   (uint16_t)rx_id, (uint32_t)staterr,
> +			   (uint16_t)rte_le_to_cpu_16(rxd.qw1.hi.len));
> +
> +		nmb = rte_mbuf_raw_alloc(rxq->mb_pool);
> +		if (nmb == NULL) {
> +			PMD_RX_LOG(DEBUG, "RX mbuf alloc failed port_id=%u "
> +				   "queue_id=%u", (uint16_t)rxq->port_id,
> +				   (uint16_t)rxq->queue_id);
> +			dev->data->rx_mbuf_alloc_failed++;
> +			break;
> +		}
> +
> +		nb_hold++;
> +		rxe = &sw_ring[rx_id];
> +		rx_id++;
> +		if (rx_id == rxq->nb_rx_desc)
> +			rx_id = 0;
> +
> +		/* Prefetch next mbuf while processing current one. */
> +		rte_ngbe_prefetch(sw_ring[rx_id].mbuf);
> +
> +		/*
> +		 * When next RX descriptor is on a cache-line boundary,
> +		 * prefetch the next 4 RX descriptors and the next 8 pointers
> +		 * to mbufs.
> +		 */
> +		if ((rx_id & 0x3) == 0) {
> +			rte_ngbe_prefetch(&rx_ring[rx_id]);
> +			rte_ngbe_prefetch(&sw_ring[rx_id]);
> +		}
> +
> +		rxm = rxe->mbuf;
> +		rxe->mbuf = nmb;
> +		dma_addr = rte_cpu_to_le_64(rte_mbuf_data_iova_default(nmb));
> +		NGBE_RXD_HDRADDR(rxdp, 0);
> +		NGBE_RXD_PKTADDR(rxdp, dma_addr);
> +
> +		/*
> +		 * Initialize the returned mbuf.
> +		 * 1) setup generic mbuf fields:
> +		 *    - number of segments,
> +		 *    - next segment,
> +		 *    - packet length,
> +		 *    - RX port identifier.
> +		 * 2) integrate hardware offload data, if any:
> +		 *    - RSS flag & hash,
> +		 *    - IP checksum flag,
> +		 *    - VLAN TCI, if any,
> +		 *    - error flags.
> +		 */
> +		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;
> +		rxm->next = NULL;
> +		rxm->pkt_len = pkt_len;
> +		rxm->data_len = pkt_len;
> +		rxm->port = rxq->port_id;
> +
> +		pkt_info = rte_le_to_cpu_32(rxd.qw0.dw0);
> +		/* Only valid if PKT_RX_VLAN set in pkt_flags */
> +		rxm->vlan_tci = rte_le_to_cpu_16(rxd.qw1.hi.tag);
> +
> +		pkt_flags = rx_desc_status_to_pkt_flags(staterr,
> +					rxq->vlan_flags);
> +		pkt_flags |= rx_desc_error_to_pkt_flags(staterr);
> +		pkt_flags |= ngbe_rxd_pkt_info_to_pkt_flags(pkt_info);
> +		rxm->ol_flags = pkt_flags;
> +		rxm->packet_type = ngbe_rxd_pkt_info_to_pkt_type(pkt_info,
> +						       rxq->pkt_type_mask);
> +
> +		if (likely(pkt_flags & PKT_RX_RSS_HASH))
> +			rxm->hash.rss = rte_le_to_cpu_32(rxd.qw0.dw1);
> +
> +		/*
> +		 * Store the mbuf address into the next entry of the array
> +		 * of returned packets.
> +		 */
> +		rx_pkts[nb_rx++] = rxm;
> +	}
> +	rxq->rx_tail = rx_id;
> +
> +	/*
> +	 * If the number of free RX descriptors is greater than the RX free

RX -> Rx

> +	 * threshold of the queue, advance the Receive Descriptor Tail (RDT)
> +	 * register.
> +	 * Update the RDT with the value of the last processed RX descriptor

RX -> Rx

> +	 * minus 1, to guarantee that the RDT register is never equal to the
> +	 * RDH register, which creates a "full" ring situation from the
> +	 * hardware point of view...
> +	 */
> +	nb_hold = (uint16_t)(nb_hold + rxq->nb_rx_hold);
> +	if (nb_hold > rxq->rx_free_thresh) {
> +		PMD_RX_LOG(DEBUG, "port_id=%u queue_id=%u rx_tail=%u "
> +			   "nb_hold=%u nb_rx=%u",
> +			   (uint16_t)rxq->port_id, (uint16_t)rxq->queue_id,
> +			   (uint16_t)rx_id, (uint16_t)nb_hold,
> +			   (uint16_t)nb_rx);
> +		rx_id = (uint16_t)((rx_id == 0) ?
> +				(rxq->nb_rx_desc - 1) : (rx_id - 1));
> +		ngbe_set32(rxq->rdt_reg_addr, rx_id);
> +		nb_hold = 0;
> +	}
> +	rxq->nb_rx_hold = nb_hold;
> +	return nb_rx;
> +}
> +
>   /*********************************************************************
>    *
>    *  Queue management functions
> diff --git a/drivers/net/ngbe/ngbe_rxtx.h b/drivers/net/ngbe/ngbe_rxtx.h
> index f30da10ae3..d6b9127cb4 100644
> --- a/drivers/net/ngbe/ngbe_rxtx.h
> +++ b/drivers/net/ngbe/ngbe_rxtx.h
> @@ -43,6 +43,85 @@ struct ngbe_rx_desc {
>   	} qw1; /* also as r.hdr_addr */
>   };
>   
> +/* @ngbe_rx_desc.qw0 */
> +#define NGBE_RXD_PKTADDR(rxd, v)  \
> +	(((volatile __le64 *)(rxd))[0] = cpu_to_le64(v))
> +
> +/* @ngbe_rx_desc.qw1 */
> +#define NGBE_RXD_HDRADDR(rxd, v)  \
> +	(((volatile __le64 *)(rxd))[1] = cpu_to_le64(v))
> +
> +/* @ngbe_rx_desc.dw0 */
> +#define NGBE_RXD_RSSTYPE(dw)      RS(dw, 0, 0xF)
> +#define   NGBE_RSSTYPE_NONE       0
> +#define   NGBE_RSSTYPE_IPV4TCP    1
> +#define   NGBE_RSSTYPE_IPV4       2
> +#define   NGBE_RSSTYPE_IPV6TCP    3
> +#define   NGBE_RSSTYPE_IPV4SCTP   4
> +#define   NGBE_RSSTYPE_IPV6       5
> +#define   NGBE_RSSTYPE_IPV6SCTP   6
> +#define   NGBE_RSSTYPE_IPV4UDP    7
> +#define   NGBE_RSSTYPE_IPV6UDP    8
> +#define   NGBE_RSSTYPE_FDIR       15
> +#define NGBE_RXD_SECTYPE(dw)      RS(dw, 4, 0x3)
> +#define NGBE_RXD_SECTYPE_NONE     LS(0, 4, 0x3)
> +#define NGBE_RXD_SECTYPE_IPSECESP LS(2, 4, 0x3)
> +#define NGBE_RXD_SECTYPE_IPSECAH  LS(3, 4, 0x3)
> +#define NGBE_RXD_TPIDSEL(dw)      RS(dw, 6, 0x7)
> +#define NGBE_RXD_PTID(dw)         RS(dw, 9, 0xFF)
> +#define NGBE_RXD_RSCCNT(dw)       RS(dw, 17, 0xF)
> +#define NGBE_RXD_HDRLEN(dw)       RS(dw, 21, 0x3FF)
> +#define NGBE_RXD_SPH              MS(31, 0x1)
> +
> +/* @ngbe_rx_desc.dw1 */
> +/** bit 0-31, as rss hash when  **/
> +#define NGBE_RXD_RSSHASH(rxd)     ((rxd)->qw0.dw1)
> +
> +/** bit 0-31, as ip csum when  **/
> +#define NGBE_RXD_IPID(rxd)        ((rxd)->qw0.hi.ipid)
> +#define NGBE_RXD_CSUM(rxd)        ((rxd)->qw0.hi.csum)
> +
> +/* @ngbe_rx_desc.dw2 */
> +#define NGBE_RXD_STATUS(rxd)      ((rxd)->qw1.lo.status)
> +/** bit 0-1 **/
> +#define NGBE_RXD_STAT_DD          MS(0, 0x1) /* Descriptor Done */
> +#define NGBE_RXD_STAT_EOP         MS(1, 0x1) /* End of Packet */
> +/** bit 2-31, when EOP=0 **/
> +#define NGBE_RXD_NEXTP_RESV(v)    LS(v, 2, 0x3)
> +#define NGBE_RXD_NEXTP(dw)        RS(dw, 4, 0xFFFF) /* Next Descriptor */
> +/** bit 2-31, when EOP=1 **/
> +#define NGBE_RXD_PKT_CLS_MASK     MS(2, 0x7) /* Packet Class */
> +#define NGBE_RXD_PKT_CLS_TC_RSS   LS(0, 2, 0x7) /* RSS Hash */
> +#define NGBE_RXD_PKT_CLS_FLM      LS(1, 2, 0x7) /* FDir Match */
> +#define NGBE_RXD_PKT_CLS_SYN      LS(2, 2, 0x7) /* TCP Sync */
> +#define NGBE_RXD_PKT_CLS_5TUPLE   LS(3, 2, 0x7) /* 5 Tuple */
> +#define NGBE_RXD_PKT_CLS_ETF      LS(4, 2, 0x7) /* Ethertype Filter */
> +#define NGBE_RXD_STAT_VLAN        MS(5, 0x1) /* IEEE VLAN Packet */
> +#define NGBE_RXD_STAT_UDPCS       MS(6, 0x1) /* UDP xsum calculated */
> +#define NGBE_RXD_STAT_L4CS        MS(7, 0x1) /* L4 xsum calculated */
> +#define NGBE_RXD_STAT_IPCS        MS(8, 0x1) /* IP xsum calculated */
> +#define NGBE_RXD_STAT_PIF         MS(9, 0x1) /* Non-unicast address */
> +#define NGBE_RXD_STAT_EIPCS       MS(10, 0x1) /* Encap IP xsum calculated */
> +#define NGBE_RXD_STAT_VEXT        MS(11, 0x1) /* Multi-VLAN */
> +#define NGBE_RXD_STAT_IPV6EX      MS(12, 0x1) /* IPv6 with option header */
> +#define NGBE_RXD_STAT_LLINT       MS(13, 0x1) /* Pkt caused LLI */
> +#define NGBE_RXD_STAT_1588        MS(14, 0x1) /* IEEE1588 Time Stamp */
> +#define NGBE_RXD_STAT_SECP        MS(15, 0x1) /* Security Processing */
> +#define NGBE_RXD_STAT_LB          MS(16, 0x1) /* Loopback Status */
> +/*** bit 17-30, when PTYPE=IP ***/
> +#define NGBE_RXD_STAT_BMC         MS(17, 0x1) /* PTYPE=IP, BMC status */
> +#define NGBE_RXD_ERR_HBO          MS(23, 0x1) /* Header Buffer Overflow */
> +#define NGBE_RXD_ERR_EIPCS        MS(26, 0x1) /* Encap IP header error */
> +#define NGBE_RXD_ERR_SECERR       MS(27, 0x1) /* macsec or ipsec error */
> +#define NGBE_RXD_ERR_RXE          MS(29, 0x1) /* Any MAC Error */
> +#define NGBE_RXD_ERR_L4CS         MS(30, 0x1) /* TCP/UDP xsum error */
> +#define NGBE_RXD_ERR_IPCS         MS(31, 0x1) /* IP xsum error */
> +#define NGBE_RXD_ERR_CSUM(dw)     RS(dw, 30, 0x3)
> +
> +/* @ngbe_rx_desc.dw3 */
> +#define NGBE_RXD_LENGTH(rxd)           ((rxd)->qw1.hi.len)
> +#define NGBE_RXD_VLAN(rxd)             ((rxd)->qw1.hi.tag)
> +
>   /*****************************************************************************
>    * Transmit Descriptor
>    *****************************************************************************/
> @@ -68,11 +147,40 @@ struct ngbe_tx_desc {
>   	__le32 dw3; /* r.olinfo_status, w.status      */
>   };
>   
> +/* @ngbe_tx_desc.dw2 */
> +#define NGBE_TXD_DATLEN(v)        ((0xFFFF & (v))) /* data buffer length */
> +#define NGBE_TXD_1588             ((0x1) << 19) /* IEEE1588 time stamp */
> +#define NGBE_TXD_DATA             ((0x0) << 20) /* data descriptor */
> +#define NGBE_TXD_EOP              ((0x1) << 24) /* End of Packet */
> +#define NGBE_TXD_FCS              ((0x1) << 25) /* Insert FCS */
> +#define NGBE_TXD_LINKSEC          ((0x1) << 26) /* Insert LinkSec */
> +#define NGBE_TXD_ECU              ((0x1) << 28) /* forward to ECU */
> +#define NGBE_TXD_CNTAG            ((0x1) << 29) /* insert CN tag */
> +#define NGBE_TXD_VLE              ((0x1) << 30) /* insert VLAN tag */
> +#define NGBE_TXD_TSE              ((0x1) << 31) /* transmit segmentation */
> +
> +#define NGBE_TXD_FLAGS (NGBE_TXD_FCS | NGBE_TXD_EOP)
> +
> +/* @ngbe_tx_desc.dw3 */
> +#define NGBE_TXD_DD_UNUSED        NGBE_TXD_DD
> +#define NGBE_TXD_IDX_UNUSED(v)    NGBE_TXD_IDX(v)
> +#define NGBE_TXD_CC               ((0x1) << 7) /* check context */
> +#define NGBE_TXD_IPSEC            ((0x1) << 8) /* request ipsec offload */
> +#define NGBE_TXD_L4CS             ((0x1) << 9) /* insert TCP/UDP/SCTP csum */
> +#define NGBE_TXD_IPCS             ((0x1) << 10) /* insert IPv4 csum */
> +#define NGBE_TXD_EIPCS            ((0x1) << 11) /* insert outer IP csum */
> +#define NGBE_TXD_MNGFLT           ((0x1) << 12) /* enable management filter */
> +#define NGBE_TXD_PAYLEN(v)        ((0x7FFFF & (v)) << 13) /* payload length */
> +
> +#define RTE_PMD_NGBE_TX_MAX_BURST 32
>   #define RTE_PMD_NGBE_RX_MAX_BURST 32
> +#define RTE_NGBE_TX_MAX_FREE_BUF_SZ 64
>   
>   #define RX_RING_SZ ((NGBE_RING_DESC_MAX + RTE_PMD_NGBE_RX_MAX_BURST) * \
>   		    sizeof(struct ngbe_rx_desc))
>   
> +#define rte_packet_prefetch(p)  rte_prefetch1(p)
> +
>   #define NGBE_TX_MAX_SEG                    40
>   
>   /**
> @@ -124,6 +232,8 @@ struct ngbe_rx_queue {
>   	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. */
> +	/** flags to set in mbuf when a vlan is detected. */
> +	uint64_t            vlan_flags;
>   	uint64_t	    offloads; /**< Rx offloads with DEV_RX_OFFLOAD_* */
>   	/** need to alloc dummy mbuf, for wraparound when scanning hw ring */
>   	struct rte_mbuf fake_mbuf;
>