ixgbe: allow rx bulk alloc

[dpdk.git] / lib / librte_pmd_ixgbe / ixgbe_rxtx.c

/*-
 *   BSD LICENSE
 * 
 *   Copyright(c) 2010-2012 Intel Corporation. All rights reserved.
 *   All rights reserved.
 * 
 *   Redistribution and use in source and binary forms, with or without 
 *   modification, are permitted provided that the following conditions 
 *   are met:
 * 
 *     * Redistributions of source code must retain the above copyright 
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright 
 *       notice, this list of conditions and the following disclaimer in 
 *       the documentation and/or other materials provided with the 
 *       distribution.
 *     * Neither the name of Intel Corporation nor the names of its 
 *       contributors may be used to endorse or promote products derived 
 *       from this software without specific prior written permission.
 * 
 *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 
 *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 
 *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 
 *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 
 *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 
 *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 
 *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 
 *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 
 *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 
 *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 
 *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 * 
 */

#include <sys/queue.h>

#include <endian.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <stdint.h>
#include <stdarg.h>
#include <unistd.h>
#include <inttypes.h>

#include <rte_byteorder.h>
#include <rte_common.h>
#include <rte_cycles.h>
#include <rte_log.h>
#include <rte_debug.h>
#include <rte_interrupts.h>
#include <rte_pci.h>
#include <rte_memory.h>
#include <rte_memzone.h>
#include <rte_launch.h>
#include <rte_tailq.h>
#include <rte_eal.h>
#include <rte_per_lcore.h>
#include <rte_lcore.h>
#include <rte_atomic.h>
#include <rte_branch_prediction.h>
#include <rte_ring.h>
#include <rte_mempool.h>
#include <rte_malloc.h>
#include <rte_mbuf.h>
#include <rte_ether.h>
#include <rte_ethdev.h>
#include <rte_prefetch.h>
#include <rte_udp.h>
#include <rte_tcp.h>
#include <rte_sctp.h>
#include <rte_string_fns.h>
#include <rte_errno.h>

#include "ixgbe_logs.h"
#include "ixgbe/ixgbe_api.h"
#include "ixgbe/ixgbe_vf.h"
#include "ixgbe_ethdev.h"

#ifdef RTE_LIBRTE_IXGBE_RX_ALLOW_BULK_ALLOC
#define RTE_PMD_IXGBE_RX_MAX_BURST 32
#endif

static inline struct rte_mbuf *
rte_rxmbuf_alloc(struct rte_mempool *mp)
{
        struct rte_mbuf *m;

        m = __rte_mbuf_raw_alloc(mp);
        __rte_mbuf_sanity_check_raw(m, RTE_MBUF_PKT, 0);
        return (m);
}

#define RTE_MBUF_DATA_DMA_ADDR(mb) \
        (uint64_t) ((mb)->buf_physaddr + (uint64_t)((char *)((mb)->pkt.data) - \
        (char *)(mb)->buf_addr))

#define RTE_MBUF_DATA_DMA_ADDR_DEFAULT(mb) \
        (uint64_t) ((mb)->buf_physaddr + RTE_PKTMBUF_HEADROOM)

/**
 * Structure associated with each descriptor of the RX ring of a RX queue.
 */
struct igb_rx_entry {
        struct rte_mbuf *mbuf; /**< mbuf associated with RX descriptor. */
};

/**
 * Structure associated with each descriptor of the TX ring of a TX queue.
 */
struct igb_tx_entry {
        struct rte_mbuf *mbuf; /**< mbuf associated with TX desc, if any. */
        uint16_t next_id; /**< Index of next descriptor in ring. */
        uint16_t last_id; /**< Index of last scattered descriptor. */
};

/**
 * Structure associated with each RX queue.
 */
struct igb_rx_queue {
        struct rte_mempool  *mb_pool; /**< mbuf pool to populate RX ring. */
        volatile union ixgbe_adv_rx_desc *rx_ring; /**< RX ring virtual address. */
        uint64_t            rx_ring_phys_addr; /**< RX ring DMA address. */
        volatile uint32_t   *rdt_reg_addr; /**< RDT register address. */
        struct igb_rx_entry *sw_ring; /**< address of RX software ring. */
        struct rte_mbuf *pkt_first_seg; /**< First segment of current packet. */
        struct rte_mbuf *pkt_last_seg; /**< Last segment of current packet. */
        uint16_t            nb_rx_desc; /**< number of RX descriptors. */
        uint16_t            rx_tail;  /**< current value of RDT register. */
        uint16_t            nb_rx_hold; /**< number of held free RX desc. */
#ifdef RTE_LIBRTE_IXGBE_RX_ALLOW_BULK_ALLOC
        uint16_t rx_nb_avail; /**< nr of staged pkts ready to ret to app */
        uint16_t rx_next_avail; /**< idx of next staged pkt to ret to app */
        uint16_t rx_free_trigger; /**< triggers rx buffer allocation */
#endif
        uint16_t            rx_free_thresh; /**< max free RX desc to hold. */
        uint16_t            queue_id; /**< RX queue index. */
        uint8_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. */
#ifdef RTE_LIBRTE_IXGBE_RX_ALLOW_BULK_ALLOC
        /** need to alloc dummy mbuf, for wraparound when scanning hw ring */
        struct rte_mbuf fake_mbuf;
        /** hold packets to return to application */
        struct rte_mbuf *rx_stage[RTE_PMD_IXGBE_RX_MAX_BURST*2];
#endif
};

/**
 * IXGBE CTX Constants
 */
enum ixgbe_advctx_num {
        IXGBE_CTX_0    = 0, /**< CTX0 */
        IXGBE_CTX_1    = 1, /**< CTX1  */
        IXGBE_CTX_NUM  = 2, /**< CTX NUMBER  */
};

/**
 * Structure to check if new context need be built
 */
struct ixgbe_advctx_info {
        uint16_t flags;           /**< ol_flags for context build. */
        uint32_t cmp_mask;        /**< compare mask for vlan_macip_lens */
        uint32_t vlan_macip_lens; /**< vlan, mac ip length. */
};

/**
 * Structure associated with each TX queue.
 */
struct igb_tx_queue {
        /** TX ring virtual address. */
        volatile union ixgbe_adv_tx_desc *tx_ring;
        uint64_t            tx_ring_phys_addr; /**< TX ring DMA address. */
        struct igb_tx_entry *sw_ring;      /**< virtual address of SW ring. */
        volatile uint32_t   *tdt_reg_addr; /**< Address of TDT register. */
        uint16_t            nb_tx_desc;    /**< number of TX descriptors. */
        uint16_t            tx_tail;       /**< current value of TDT reg. */
        uint16_t            tx_free_thresh;/**< minimum TX before freeing. */
        /** Number of TX descriptors to use before RS bit is set. */
        uint16_t            tx_rs_thresh;
        /** Number of TX descriptors used since RS bit was set. */
        uint16_t            nb_tx_used;
        /** Index to last TX descriptor to have been cleaned. */
        uint16_t            last_desc_cleaned;
        /** Total number of TX descriptors ready to be allocated. */
        uint16_t            nb_tx_free;
        uint16_t            queue_id;      /**< TX queue index. */
        uint8_t             port_id;       /**< Device port identifier. */
        uint8_t             pthresh;       /**< Prefetch threshold register. */
        uint8_t             hthresh;       /**< Host threshold register. */
        uint8_t             wthresh;       /**< Write-back threshold reg. */
        uint32_t            ctx_curr;      /**< Hardware context states. */
        /** Hardware context0 history. */
        struct ixgbe_advctx_info ctx_cache[IXGBE_CTX_NUM];
};


#if 1
#define RTE_PMD_USE_PREFETCH
#endif

#ifdef RTE_PMD_USE_PREFETCH
/*
 * Prefetch a cache line into all cache levels.
 */
#define rte_ixgbe_prefetch(p)   rte_prefetch0(p)
#else
#define rte_ixgbe_prefetch(p)   do {} while(0)
#endif

#ifdef RTE_PMD_PACKET_PREFETCH
#define rte_packet_prefetch(p)  rte_prefetch1(p)
#else
#define rte_packet_prefetch(p)  do {} while(0)
#endif

/*********************************************************************
 *
 *  TX functions
 *
 **********************************************************************/
static inline void
ixgbe_set_xmit_ctx(struct igb_tx_queue* txq,
                volatile struct ixgbe_adv_tx_context_desc *ctx_txd,
                uint16_t ol_flags, uint32_t vlan_macip_lens)
{
        uint32_t type_tucmd_mlhl;
        uint32_t mss_l4len_idx;
        uint32_t ctx_idx;
        uint32_t cmp_mask;

        ctx_idx = txq->ctx_curr;
        cmp_mask = 0;
        type_tucmd_mlhl = 0;

        if (ol_flags & PKT_TX_VLAN_PKT) {
                cmp_mask |= TX_VLAN_CMP_MASK;
        }

        if (ol_flags & PKT_TX_IP_CKSUM) {
                type_tucmd_mlhl = IXGBE_ADVTXD_TUCMD_IPV4;
                cmp_mask |= TX_MAC_LEN_CMP_MASK;
        }

        /* Specify which HW CTX to upload. */
        mss_l4len_idx = (ctx_idx << IXGBE_ADVTXD_IDX_SHIFT);
        switch (ol_flags & PKT_TX_L4_MASK) {
        case PKT_TX_UDP_CKSUM:
                type_tucmd_mlhl |= IXGBE_ADVTXD_TUCMD_L4T_UDP |
                                IXGBE_ADVTXD_DTYP_CTXT | IXGBE_ADVTXD_DCMD_DEXT;
                mss_l4len_idx |= sizeof(struct udp_hdr) << IXGBE_ADVTXD_L4LEN_SHIFT;
                cmp_mask |= TX_MACIP_LEN_CMP_MASK;
                break;
        case PKT_TX_TCP_CKSUM:
                type_tucmd_mlhl |= IXGBE_ADVTXD_TUCMD_L4T_TCP |
                                IXGBE_ADVTXD_DTYP_CTXT | IXGBE_ADVTXD_DCMD_DEXT;
                mss_l4len_idx |= sizeof(struct tcp_hdr) << IXGBE_ADVTXD_L4LEN_SHIFT;
                cmp_mask |= TX_MACIP_LEN_CMP_MASK;
                break;
        case PKT_TX_SCTP_CKSUM:
                type_tucmd_mlhl |= IXGBE_ADVTXD_TUCMD_L4T_SCTP |
                                IXGBE_ADVTXD_DTYP_CTXT | IXGBE_ADVTXD_DCMD_DEXT;
                mss_l4len_idx |= sizeof(struct sctp_hdr) << IXGBE_ADVTXD_L4LEN_SHIFT;
                cmp_mask |= TX_MACIP_LEN_CMP_MASK;
                break;
        default:
                type_tucmd_mlhl |= IXGBE_ADVTXD_TUCMD_L4T_RSV |
                                IXGBE_ADVTXD_DTYP_CTXT | IXGBE_ADVTXD_DCMD_DEXT;
                break;
        }

        txq->ctx_cache[ctx_idx].flags = ol_flags;
        txq->ctx_cache[ctx_idx].cmp_mask = cmp_mask;
        txq->ctx_cache[ctx_idx].vlan_macip_lens = vlan_macip_lens & cmp_mask;

        ctx_txd->type_tucmd_mlhl = rte_cpu_to_le_32(type_tucmd_mlhl);
        ctx_txd->vlan_macip_lens = rte_cpu_to_le_32(vlan_macip_lens);
        ctx_txd->mss_l4len_idx   = rte_cpu_to_le_32(mss_l4len_idx);
        ctx_txd->seqnum_seed     = 0;
}

/*
 * Check which hardware context can be used. Use the existing match
 * or create a new context descriptor.
 */
static inline uint32_t
what_advctx_update(struct igb_tx_queue *txq, uint16_t flags,
                uint32_t vlan_macip_lens)
{
        /* If match with the current used context */
        if (likely((txq->ctx_cache[txq->ctx_curr].flags == flags) &&
                (txq->ctx_cache[txq->ctx_curr].vlan_macip_lens ==
                (txq->ctx_cache[txq->ctx_curr].cmp_mask & vlan_macip_lens)))) {
                        return txq->ctx_curr;
        }

        /* What if match with the next context  */
        txq->ctx_curr ^= 1;
        if (likely((txq->ctx_cache[txq->ctx_curr].flags == flags) &&
                (txq->ctx_cache[txq->ctx_curr].vlan_macip_lens ==
                (txq->ctx_cache[txq->ctx_curr].cmp_mask & vlan_macip_lens)))) {
                        return txq->ctx_curr;
        }

        /* Mismatch, use the previous context */
        return (IXGBE_CTX_NUM);
}

static inline uint32_t
tx_desc_cksum_flags_to_olinfo(uint16_t ol_flags)
{
        static const uint32_t l4_olinfo[2] = {0, IXGBE_ADVTXD_POPTS_TXSM};
        static const uint32_t l3_olinfo[2] = {0, IXGBE_ADVTXD_POPTS_IXSM};
        uint32_t tmp;

        tmp  = l4_olinfo[(ol_flags & PKT_TX_L4_MASK)  != PKT_TX_L4_NO_CKSUM];
        tmp |= l3_olinfo[(ol_flags & PKT_TX_IP_CKSUM) != 0];
        return tmp;
}

static inline uint32_t
tx_desc_vlan_flags_to_cmdtype(uint16_t ol_flags)
{
        static const uint32_t vlan_cmd[2] = {0, IXGBE_ADVTXD_DCMD_VLE};
        return vlan_cmd[(ol_flags & PKT_TX_VLAN_PKT) != 0];
}

/* Default RS bit threshold values */
#ifndef DEFAULT_TX_RS_THRESH
#define DEFAULT_TX_RS_THRESH   32
#endif
#ifndef DEFAULT_TX_FREE_THRESH
#define DEFAULT_TX_FREE_THRESH 32
#endif

/* Reset transmit descriptors after they have been used */
static inline int
ixgbe_xmit_cleanup(struct igb_tx_queue *txq)
{
        struct igb_tx_entry *sw_ring = txq->sw_ring;
        volatile union ixgbe_adv_tx_desc *txr = txq->tx_ring;
        uint16_t last_desc_cleaned = txq->last_desc_cleaned;
        uint16_t nb_tx_desc = txq->nb_tx_desc;
        uint16_t desc_to_clean_to;
        uint16_t nb_tx_to_clean;

        /* Determine the last descriptor needing to be cleaned */
        desc_to_clean_to = last_desc_cleaned + txq->tx_rs_thresh;
        if (desc_to_clean_to >= nb_tx_desc)
                desc_to_clean_to = desc_to_clean_to - nb_tx_desc;

        /* Check to make sure the last descriptor to clean is done */
        desc_to_clean_to = sw_ring[desc_to_clean_to].last_id;
        if (! (txr[desc_to_clean_to].wb.status & IXGBE_TXD_STAT_DD))
        {
                PMD_TX_FREE_LOG(DEBUG,
                                "TX descriptor %4u is not done"
                                "(port=%d queue=%d)",
                                desc_to_clean_to,
                                txq->port_id, txq->queue_id);
                /* Failed to clean any descriptors, better luck next time */
                return -(1);
        }

        /* Figure out how many descriptors will be cleaned */
        if (last_desc_cleaned > desc_to_clean_to)
                nb_tx_to_clean = ((nb_tx_desc - last_desc_cleaned) +
                                  desc_to_clean_to);
        else
                nb_tx_to_clean = desc_to_clean_to - last_desc_cleaned;

        PMD_TX_FREE_LOG(DEBUG,
                        "Cleaning %4u TX descriptors: %4u to %4u "
                        "(port=%d queue=%d)",
                        nb_tx_to_clean, last_desc_cleaned, desc_to_clean_to,
                        txq->port_id, txq->queue_id);

        /*
         * The last descriptor to clean is done, so that means all the
         * descriptors from the last descriptor that was cleaned
         * up to the last descriptor with the RS bit set
         * are done. Only reset the threshold descriptor.
         */
        txr[desc_to_clean_to].wb.status = 0;

        /* Update the txq to reflect the last descriptor that was cleaned */
        txq->last_desc_cleaned = desc_to_clean_to;
        txq->nb_tx_free += nb_tx_to_clean;

        /* No Error */
        return (0);
}

uint16_t
ixgbe_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
                uint16_t nb_pkts)
{
        struct igb_tx_queue *txq;
        struct igb_tx_entry *sw_ring;
        struct igb_tx_entry *txe, *txn;
        volatile union ixgbe_adv_tx_desc *txr;
        volatile union ixgbe_adv_tx_desc *txd;
        struct rte_mbuf     *tx_pkt;
        struct rte_mbuf     *m_seg;
        uint64_t buf_dma_addr;
        uint32_t olinfo_status;
        uint32_t cmd_type_len;
        uint32_t pkt_len;
        uint16_t slen;
        uint16_t ol_flags;
        uint16_t tx_id;
        uint16_t tx_last;
        uint16_t nb_tx;
        uint16_t nb_used;
        uint16_t tx_ol_req;
        uint32_t vlan_macip_lens;
        uint32_t ctx;
        uint32_t new_ctx;

        txq = tx_queue;
        sw_ring = txq->sw_ring;
        txr     = txq->tx_ring;
        tx_id   = txq->tx_tail;
        txe = &sw_ring[tx_id];

        /* Determine if the descriptor ring needs to be cleaned. */
        if ((txq->nb_tx_desc - txq->nb_tx_free) > txq->tx_free_thresh) {
                ixgbe_xmit_cleanup(txq);
        }

        /* TX loop */
        for (nb_tx = 0; nb_tx < nb_pkts; nb_tx++) {
                new_ctx = 0;
                tx_pkt = *tx_pkts++;
                pkt_len = tx_pkt->pkt.pkt_len;

                RTE_MBUF_PREFETCH_TO_FREE(txe->mbuf);

                /*
                 * Determine how many (if any) context descriptors
                 * are needed for offload functionality.
                 */
                ol_flags = tx_pkt->ol_flags;
                vlan_macip_lens = tx_pkt->pkt.vlan_tci << 16 |
                                tx_pkt->pkt.l2_len << IXGBE_ADVTXD_MACLEN_SHIFT |
                                tx_pkt->pkt.l3_len;

                /* If hardware offload required */
                tx_ol_req = ol_flags & PKT_TX_OFFLOAD_MASK;
                if (tx_ol_req) {
                        /* If new context need be built or reuse the exist ctx. */
                        ctx = what_advctx_update(txq, tx_ol_req, vlan_macip_lens);
                        /* Only allocate context descriptor if required*/
                        new_ctx = (ctx == IXGBE_CTX_NUM);
                        ctx = txq->ctx_curr;
                }

                /*
                 * Keep track of how many descriptors are used this loop
                 * This will always be the number of segments + the number of
                 * Context descriptors required to transmit the packet
                 */
                nb_used = tx_pkt->pkt.nb_segs + new_ctx;

                /*
                 * The number of descriptors that must be allocated for a
                 * packet is the number of segments of that packet, plus 1
                 * Context Descriptor for the hardware offload, if any.
                 * Determine the last TX descriptor to allocate in the TX ring
                 * for the packet, starting from the current position (tx_id)
                 * in the ring.
                 */
                tx_last = (uint16_t) (tx_id + nb_used - 1);

                /* Circular ring */
                if (tx_last >= txq->nb_tx_desc)
                        tx_last = (uint16_t) (tx_last - txq->nb_tx_desc);

                PMD_TX_LOG(DEBUG, "port_id=%u queue_id=%u pktlen=%u"
                           " tx_first=%u tx_last=%u\n",
                           (unsigned) txq->port_id,
                           (unsigned) txq->queue_id,
                           (unsigned) pkt_len,
                           (unsigned) tx_id,
                           (unsigned) tx_last);

                /*
                 * Make sure there are enough TX descriptors available to
                 * transmit the entire packet.
                 * nb_used better be less than or equal to txq->tx_rs_thresh
                 */
                if (nb_used > txq->nb_tx_free) {
                        PMD_TX_FREE_LOG(DEBUG,
                                        "Not enough free TX descriptors "
                                        "nb_used=%4u nb_free=%4u "
                                        "(port=%d queue=%d)",
                                        nb_used, txq->nb_tx_free,
                                        txq->port_id, txq->queue_id);

                        if (ixgbe_xmit_cleanup(txq) != 0) {
                                /* Could not clean any descriptors */
                                if (nb_tx == 0)
                                        return (0);
                                goto end_of_tx;
                        }

                        /* nb_used better be <= txq->tx_rs_thresh */
                        if (unlikely(nb_used > txq->tx_rs_thresh)) {
                                PMD_TX_FREE_LOG(DEBUG,
                                        "The number of descriptors needed to "
                                        "transmit the packet exceeds the "
                                        "RS bit threshold. This will impact "
                                        "performance."
                                        "nb_used=%4u nb_free=%4u "
                                        "tx_rs_thresh=%4u. "
                                        "(port=%d queue=%d)",
                                        nb_used, txq->nb_tx_free,
                                        txq->tx_rs_thresh,
                                        txq->port_id, txq->queue_id);
                                /*
                                 * Loop here until there are enough TX
                                 * descriptors or until the ring cannot be
                                 * cleaned.
                                 */
                                while (nb_used > txq->nb_tx_free) {
                                        if (ixgbe_xmit_cleanup(txq) != 0) {
                                                /*
                                                 * Could not clean any
                                                 * descriptors
                                                 */
                                                if (nb_tx == 0)
                                                        return (0);
                                                goto end_of_tx;
                                        }
                                }
                        }
                }

                /*
                 * By now there are enough free TX descriptors to transmit
                 * the packet.
                 */

                /*
                 * Set common flags of all TX Data Descriptors.
                 *
                 * The following bits must be set in all Data Descriptors:
                 *   - IXGBE_ADVTXD_DTYP_DATA
                 *   - IXGBE_ADVTXD_DCMD_DEXT
                 *
                 * The following bits must be set in the first Data Descriptor
                 * and are ignored in the other ones:
                 *   - IXGBE_ADVTXD_DCMD_IFCS
                 *   - IXGBE_ADVTXD_MAC_1588
                 *   - IXGBE_ADVTXD_DCMD_VLE
                 *
                 * The following bits must only be set in the last Data
                 * Descriptor:
                 *   - IXGBE_TXD_CMD_EOP
                 *
                 * The following bits can be set in any Data Descriptor, but
                 * are only set in the last Data Descriptor:
                 *   - IXGBE_TXD_CMD_RS
                 */
                cmd_type_len = IXGBE_ADVTXD_DTYP_DATA |
                        IXGBE_ADVTXD_DCMD_IFCS | IXGBE_ADVTXD_DCMD_DEXT;
                olinfo_status = (pkt_len << IXGBE_ADVTXD_PAYLEN_SHIFT);
#ifdef RTE_LIBRTE_IEEE1588
                if (ol_flags & PKT_TX_IEEE1588_TMST)
                        cmd_type_len |= IXGBE_ADVTXD_MAC_1588;
#endif

                if (tx_ol_req) {
                        /*
                         * Setup the TX Advanced Context Descriptor if required
                         */
                        if (new_ctx) {
                                volatile struct ixgbe_adv_tx_context_desc *
                                    ctx_txd;

                                ctx_txd = (volatile struct
                                    ixgbe_adv_tx_context_desc *)
                                    &txr[tx_id];

                                txn = &sw_ring[txe->next_id];
                                RTE_MBUF_PREFETCH_TO_FREE(txn->mbuf);

                                if (txe->mbuf != NULL) {
                                        rte_pktmbuf_free_seg(txe->mbuf);
                                        txe->mbuf = NULL;
                                }

                                ixgbe_set_xmit_ctx(txq, ctx_txd, tx_ol_req,
                                    vlan_macip_lens);

                                txe->last_id = tx_last;
                                tx_id = txe->next_id;
                                txe = txn;
                        }

                        /*
                         * Setup the TX Advanced Data Descriptor,
                         * This path will go through
                         * whatever new/reuse the context descriptor
                         */
                        cmd_type_len  |= tx_desc_vlan_flags_to_cmdtype(ol_flags);
                        olinfo_status |= tx_desc_cksum_flags_to_olinfo(ol_flags);
                        olinfo_status |= ctx << IXGBE_ADVTXD_IDX_SHIFT;
                }

                m_seg = tx_pkt;
                do {
                        txd = &txr[tx_id];
                        txn = &sw_ring[txe->next_id];

                        if (txe->mbuf != NULL)
                                rte_pktmbuf_free_seg(txe->mbuf);
                        txe->mbuf = m_seg;

                        /*
                         * Set up Transmit Data Descriptor.
                         */
                        slen = m_seg->pkt.data_len;
                        buf_dma_addr = RTE_MBUF_DATA_DMA_ADDR(m_seg);
                        txd->read.buffer_addr =
                                rte_cpu_to_le_64(buf_dma_addr);
                        txd->read.cmd_type_len =
                                rte_cpu_to_le_32(cmd_type_len | slen);
                        txd->read.olinfo_status =
                                rte_cpu_to_le_32(olinfo_status);
                        txe->last_id = tx_last;
                        tx_id = txe->next_id;
                        txe = txn;
                        m_seg = m_seg->pkt.next;
                } while (m_seg != NULL);

                /*
                 * The last packet data descriptor needs End Of Packet (EOP)
                 */
                cmd_type_len |= IXGBE_TXD_CMD_EOP;
                txq->nb_tx_used += nb_used;
                txq->nb_tx_free -= nb_used;

                /* Set RS bit only on threshold packets' last descriptor */
                if (txq->nb_tx_used >= txq->tx_rs_thresh) {
                        PMD_TX_FREE_LOG(DEBUG,
                                        "Setting RS bit on TXD id="
                                        "%4u (port=%d queue=%d)",
                                        tx_last, txq->port_id, txq->queue_id);

                        cmd_type_len |= IXGBE_TXD_CMD_RS;

                        /* Update txq RS bit counters */
                        txq->nb_tx_used = 0;
                }
                txd->read.cmd_type_len |= rte_cpu_to_le_32(cmd_type_len);
        }
end_of_tx:
        rte_wmb();

        /*
         * Set the Transmit Descriptor Tail (TDT)
         */
        PMD_TX_LOG(DEBUG, "port_id=%u queue_id=%u tx_tail=%u nb_tx=%u",
                   (unsigned) txq->port_id, (unsigned) txq->queue_id,
                   (unsigned) tx_id, (unsigned) nb_tx);
        IXGBE_PCI_REG_WRITE(txq->tdt_reg_addr, tx_id);
        txq->tx_tail = tx_id;

        return (nb_tx);
}

/*********************************************************************
 *
 *  RX functions
 *
 **********************************************************************/
static inline uint16_t
rx_desc_hlen_type_rss_to_pkt_flags(uint32_t hl_tp_rs)
{
        uint16_t pkt_flags;

        static uint16_t ip_pkt_types_map[16] = {
                0, PKT_RX_IPV4_HDR, PKT_RX_IPV4_HDR_EXT, PKT_RX_IPV4_HDR_EXT,
                PKT_RX_IPV6_HDR, 0, 0, 0,
                PKT_RX_IPV6_HDR_EXT, 0, 0, 0,
                PKT_RX_IPV6_HDR_EXT, 0, 0, 0,
        };

        static uint16_t ip_rss_types_map[16] = {
                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,
        };

#ifdef RTE_LIBRTE_IEEE1588
        static uint32_t ip_pkt_etqf_map[8] = {
                0, 0, 0, PKT_RX_IEEE1588_PTP,
                0, 0, 0, 0,
        };

        pkt_flags = (uint16_t) ((hl_tp_rs & IXGBE_RXDADV_PKTTYPE_ETQF) ?
                                ip_pkt_etqf_map[(hl_tp_rs >> 4) & 0x07] :
                                ip_pkt_types_map[(hl_tp_rs >> 4) & 0x0F]);
#else
        pkt_flags = (uint16_t) ((hl_tp_rs & IXGBE_RXDADV_PKTTYPE_ETQF) ? 0 :
                                ip_pkt_types_map[(hl_tp_rs >> 4) & 0x0F]);

#endif
        return (pkt_flags | ip_rss_types_map[hl_tp_rs & 0xF]);
}

static inline uint16_t
rx_desc_status_to_pkt_flags(uint32_t rx_status)
{
        uint16_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.hw_ip_checksum flag
         */
        pkt_flags = (uint16_t) (rx_status & IXGBE_RXD_STAT_VP) ? PKT_RX_VLAN_PKT : 0;

#ifdef RTE_LIBRTE_IEEE1588
        if (rx_status & IXGBE_RXD_STAT_TMST)
                pkt_flags = (pkt_flags | PKT_RX_IEEE1588_TMST);
#endif
        return pkt_flags;
}

static inline uint16_t
rx_desc_error_to_pkt_flags(uint32_t rx_status)
{
        /*
         * Bit 31: IPE, IPv4 checksum error
         * Bit 30: L4I, L4I integrity error
         */
        static uint16_t error_to_pkt_flags_map[4] = {
                0,  PKT_RX_L4_CKSUM_BAD, PKT_RX_IP_CKSUM_BAD,
                PKT_RX_IP_CKSUM_BAD | PKT_RX_L4_CKSUM_BAD
        };
        return error_to_pkt_flags_map[(rx_status >>
                IXGBE_RXDADV_ERR_CKSUM_BIT) & IXGBE_RXDADV_ERR_CKSUM_MSK];
}

#ifdef RTE_LIBRTE_IXGBE_RX_ALLOW_BULK_ALLOC
/*
 * LOOK_AHEAD defines how many desc statuses to check beyond the
 * current descriptor. 
 * It must be a pound define for optimal performance.
 * Do not change the value of LOOK_AHEAD, as the ixgbe_rx_scan_hw_ring
 * function only works with LOOK_AHEAD=8.
 */
#define LOOK_AHEAD 8
#if (LOOK_AHEAD != 8)
#error "PMD IXGBE: LOOK_AHEAD must be 8\n"
#endif
static inline int
ixgbe_rx_scan_hw_ring(struct igb_rx_queue *rxq)
{
        volatile union ixgbe_adv_rx_desc *rxdp;
        struct igb_rx_entry *rxep;
        struct rte_mbuf *mb;
        uint16_t pkt_len;
        int s[LOOK_AHEAD], nb_dd;
        int i, j, nb_rx = 0;


        /* get references to current descriptor and S/W ring entry */
        rxdp = &rxq->rx_ring[rxq->rx_tail];
        rxep = &rxq->sw_ring[rxq->rx_tail];

        /* check to make sure there is at least 1 packet to receive */
        if (! (rxdp->wb.upper.status_error & IXGBE_RXDADV_STAT_DD))
                return 0;

        /*
         * Scan LOOK_AHEAD descriptors at a time to determine which descriptors
         * reference packets that are ready to be received.
         */
        for (i = 0; i < RTE_PMD_IXGBE_RX_MAX_BURST;
             i += LOOK_AHEAD, rxdp += LOOK_AHEAD, rxep += LOOK_AHEAD)
        {
                /* Read desc statuses backwards to avoid race condition */
                for (j = LOOK_AHEAD-1; j >= 0; --j)
                        s[j] = rxdp[j].wb.upper.status_error;

                /* Clear everything but the status bits (LSB) */
                for (j = 0; j < LOOK_AHEAD; ++j)
                        s[j] &= IXGBE_RXDADV_STAT_DD;

                /* Compute how many status bits were set */
                nb_dd = s[0]+s[1]+s[2]+s[3]+s[4]+s[5]+s[6]+s[7];
                nb_rx += nb_dd;

                /* Translate descriptor info to mbuf format */
                for (j = 0; j < nb_dd; ++j) {
                        mb = rxep[j].mbuf;
                        pkt_len = rxdp[j].wb.upper.length - rxq->crc_len;
                        mb->pkt.data_len = pkt_len;
                        mb->pkt.pkt_len = pkt_len;
                        mb->pkt.vlan_macip.f.vlan_tci = rxdp[j].wb.upper.vlan;
                        mb->pkt.hash.rss = rxdp[j].wb.lower.hi_dword.rss;

                        /* convert descriptor fields to rte mbuf flags */
                        mb->ol_flags  = rx_desc_hlen_type_rss_to_pkt_flags(
                                        rxdp[j].wb.lower.lo_dword.data);
                        /* reuse status field from scan list */
                        mb->ol_flags |= rx_desc_status_to_pkt_flags(s[j]);
                        mb->ol_flags |= rx_desc_error_to_pkt_flags(s[j]);
                }

                /* Move mbuf pointers from the S/W ring to the stage */
                for (j = 0; j < LOOK_AHEAD; ++j) {
                        rxq->rx_stage[i + j] = rxep[j].mbuf;
                }

                /* stop if all requested packets could not be received */
                if (nb_dd != LOOK_AHEAD)
                        break;
        }

        /* clear software ring entries so we can cleanup correctly */
        for (i = 0; i < nb_rx; ++i)
                rxq->sw_ring[rxq->rx_tail + i].mbuf = NULL;

        return nb_rx;
}

static inline int
ixgbe_rx_alloc_bufs(struct igb_rx_queue *rxq)
{
        volatile union ixgbe_adv_rx_desc *rxdp;
        struct igb_rx_entry *rxep;
        struct rte_mbuf *mb;
        uint16_t alloc_idx;
        uint64_t dma_addr;
        int diag, i;

        /* allocate buffers in bulk directly into the S/W ring */
        alloc_idx = rxq->rx_free_trigger - (rxq->rx_free_thresh - 1);
        rxep = &rxq->sw_ring[alloc_idx];
        diag = rte_mempool_get_bulk(rxq->mb_pool, (void *)rxep,
                                    rxq->rx_free_thresh);
        if (unlikely(diag != 0))
                return (-ENOMEM);

        rxdp = &rxq->rx_ring[alloc_idx];
        for (i = 0; i < rxq->rx_free_thresh; ++i) {
                /* populate the static rte mbuf fields */
                mb = rxep[i].mbuf;
                rte_mbuf_refcnt_set(mb, 1);
                mb->type = RTE_MBUF_PKT;
                mb->pkt.next = NULL;
                mb->pkt.data = (char *)mb->buf_addr + RTE_PKTMBUF_HEADROOM;
                mb->pkt.nb_segs = 1;
                mb->pkt.in_port = rxq->port_id;

                /* populate the descriptors */
                dma_addr = (uint64_t)mb->buf_physaddr + RTE_PKTMBUF_HEADROOM;
                rxdp[i].read.hdr_addr = dma_addr;
                rxdp[i].read.pkt_addr = dma_addr;
        }

        /* update tail pointer */
        rte_wmb();
        IXGBE_PCI_REG_WRITE(rxq->rdt_reg_addr, rxq->rx_free_trigger);

        /* update state of internal queue structure */
        rxq->rx_free_trigger += rxq->rx_free_thresh;
        if (rxq->rx_free_trigger >= rxq->nb_rx_desc)
                rxq->rx_free_trigger = (rxq->rx_free_thresh - 1);

        /* no errors */
        return 0;
}

static inline uint16_t
ixgbe_rx_fill_from_stage(struct igb_rx_queue *rxq, struct rte_mbuf **rx_pkts,
                         uint16_t nb_pkts)
{
        struct rte_mbuf **stage = &rxq->rx_stage[rxq->rx_next_avail];
        int i;

        /* how many packets are ready to return? */
        nb_pkts = RTE_MIN(nb_pkts, rxq->rx_nb_avail);

        /* copy mbuf pointers to the application's packet list */
        for (i = 0; i < nb_pkts; ++i)
                rx_pkts[i] = stage[i];

        /* update internal queue state */
        rxq->rx_nb_avail -= nb_pkts;
        rxq->rx_next_avail += nb_pkts;

        return nb_pkts;
}

static inline uint16_t
rx_recv_pkts(void *rx_queue, struct rte_mbuf **rx_pkts,
             uint16_t nb_pkts)
{
        struct igb_rx_queue *rxq = (struct igb_rx_queue *)rx_queue;
        uint16_t nb_rx = 0;

        /* Any previously recv'd pkts will be returned from the Rx stage */
        if (rxq->rx_nb_avail)
                return ixgbe_rx_fill_from_stage(rxq, rx_pkts, nb_pkts);

        /* Scan the H/W ring for packets to receive */
        nb_rx = ixgbe_rx_scan_hw_ring(rxq);

        /* update internal queue state */
        rxq->rx_next_avail = 0;
        rxq->rx_nb_avail = nb_rx;
        rxq->rx_tail += nb_rx;

        /* if required, allocate new buffers to replenish descriptors */
        if (rxq->rx_tail > rxq->rx_free_trigger) {
                if (ixgbe_rx_alloc_bufs(rxq) != 0) {
                        int i, j;
                        PMD_RX_LOG(DEBUG, "RX mbuf alloc failed port_id=%u "
                                   "queue_id=%u\n", (unsigned) rxq->port_id,
                                   (unsigned) rxq->queue_id);

                        rte_eth_devices[rxq->port_id].data->rx_mbuf_alloc_failed +=
                                rxq->rx_free_thresh;

                        /*
                         * Need to rewind any previous receives if we cannot
                         * allocate new buffers to replenish the old ones.
                         */
                        rxq->rx_nb_avail = 0;
                        rxq->rx_tail -= nb_rx;
                        for (i = 0, j = rxq->rx_tail; i < nb_rx; ++i, ++j)
                                rxq->sw_ring[j].mbuf = rxq->rx_stage[i];

                        return 0;
                }
        }

        if (rxq->rx_tail >= rxq->nb_rx_desc)
                rxq->rx_tail = 0;

        /* received any packets this loop? */
        if (rxq->rx_nb_avail)
                return ixgbe_rx_fill_from_stage(rxq, rx_pkts, nb_pkts);

        return 0;
}

/* split requests into chunks of size RTE_PMD_IXGBE_RX_MAX_BURST */
uint16_t
ixgbe_recv_pkts_bulk_alloc(void *rx_queue, struct rte_mbuf **rx_pkts,
                uint16_t nb_pkts)
{
        uint16_t nb_rx;

        if (unlikely(nb_pkts == 0))
                return 0;

        if (likely(nb_pkts <= RTE_PMD_IXGBE_RX_MAX_BURST))
                return rx_recv_pkts(rx_queue, rx_pkts, nb_pkts);

        /* request is relatively large, chunk it up */
        nb_rx = 0;
        while (nb_pkts) {
                uint16_t ret, n;
                n = RTE_MIN(nb_pkts, RTE_PMD_IXGBE_RX_MAX_BURST);
                ret = rx_recv_pkts(rx_queue, &rx_pkts[nb_rx], n);
                nb_rx += ret;
                nb_pkts -= ret;
                if (ret < n)
                        break;
        }

        return nb_rx;
}
#endif /* RTE_LIBRTE_IXGBE_RX_ALLOW_BULK_ALLOC */

uint16_t
ixgbe_recv_pkts(void *rx_queue, struct rte_mbuf **rx_pkts,
                uint16_t nb_pkts)
{
        struct igb_rx_queue *rxq;
        volatile union ixgbe_adv_rx_desc *rx_ring;
        volatile union ixgbe_adv_rx_desc *rxdp;
        struct igb_rx_entry *sw_ring;
        struct igb_rx_entry *rxe;
        struct rte_mbuf *rxm;
        struct rte_mbuf *nmb;
        union ixgbe_adv_rx_desc rxd;
        uint64_t dma_addr;
        uint32_t staterr;
        uint32_t hlen_type_rss;
        uint16_t pkt_len;
        uint16_t rx_id;
        uint16_t nb_rx;
        uint16_t nb_hold;
        uint16_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;
        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->wb.upper.status_error;
                if (! (staterr & rte_cpu_to_le_32(IXGBE_RXDADV_STAT_DD)))
                        break;
                rxd = *rxdp;

                /*
                 * End of packet.
                 *
                 * If the IXGBE_RXDADV_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\n",
                           (unsigned) rxq->port_id, (unsigned) rxq->queue_id,
                           (unsigned) rx_id, (unsigned) staterr,
                           (unsigned) rte_le_to_cpu_16(rxd.wb.upper.length));

                nmb = rte_rxmbuf_alloc(rxq->mb_pool);
                if (nmb == NULL) {
                        PMD_RX_LOG(DEBUG, "RX mbuf alloc failed port_id=%u "
                                   "queue_id=%u\n", (unsigned) rxq->port_id,
                                   (unsigned) rxq->queue_id);
                        rte_eth_devices[rxq->port_id].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_ixgbe_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_ixgbe_prefetch(&rx_ring[rx_id]);
                        rte_ixgbe_prefetch(&sw_ring[rx_id]);
                }

                rxm = rxe->mbuf;
                rxe->mbuf = nmb;
                dma_addr =
                        rte_cpu_to_le_64(RTE_MBUF_DATA_DMA_ADDR_DEFAULT(nmb));
                rxdp->read.hdr_addr = dma_addr;
                rxdp->read.pkt_addr = 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.wb.upper.length) -
                                      rxq->crc_len);
                rxm->pkt.data = (char*) rxm->buf_addr + RTE_PKTMBUF_HEADROOM;
                rte_packet_prefetch(rxm->pkt.data);
                rxm->pkt.nb_segs = 1;
                rxm->pkt.next = NULL;
                rxm->pkt.pkt_len = pkt_len;
                rxm->pkt.data_len = pkt_len;
                rxm->pkt.in_port = rxq->port_id;

                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->pkt.vlan_tci = rte_le_to_cpu_16(rxd.wb.upper.vlan);

                pkt_flags = rx_desc_hlen_type_rss_to_pkt_flags(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));
                rxm->ol_flags = pkt_flags;

                if (likely(pkt_flags & PKT_RX_RSS_HASH))
                        rxm->pkt.hash.rss = rxd.wb.lower.hi_dword.rss;
                else if (pkt_flags & PKT_RX_FDIR) {
                        rxm->pkt.hash.fdir.hash =
                                (uint16_t)((rxd.wb.lower.hi_dword.csum_ip.csum)
                                           & IXGBE_ATR_HASH_MASK);
                        rxm->pkt.hash.fdir.id = rxd.wb.lower.hi_dword.csum_ip.ip_id;
                }
                /*
                 * 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
         * threshold of the queue, advance the Receive Descriptor Tail (RDT)
         * register.
         * Update the RDT with the value of the last processed RX descriptor
         * minus 1, to guarantee that the RDT register is never equal to the
         * RDH register, which creates a "full" ring situtation 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\n",
                           (unsigned) rxq->port_id, (unsigned) rxq->queue_id,
                           (unsigned) rx_id, (unsigned) nb_hold,
                           (unsigned) nb_rx);
                rx_id = (uint16_t) ((rx_id == 0) ?
                                     (rxq->nb_rx_desc - 1) : (rx_id - 1));
                IXGBE_PCI_REG_WRITE(rxq->rdt_reg_addr, rx_id);
                nb_hold = 0;
        }
        rxq->nb_rx_hold = nb_hold;
        return (nb_rx);
}

uint16_t
ixgbe_recv_scattered_pkts(void *rx_queue, struct rte_mbuf **rx_pkts,
                          uint16_t nb_pkts)
{
        struct igb_rx_queue *rxq;
        volatile union ixgbe_adv_rx_desc *rx_ring;
        volatile union ixgbe_adv_rx_desc *rxdp;
        struct igb_rx_entry *sw_ring;
        struct igb_rx_entry *rxe;
        struct rte_mbuf *first_seg;
        struct rte_mbuf *last_seg;
        struct rte_mbuf *rxm;
        struct rte_mbuf *nmb;
        union ixgbe_adv_rx_desc rxd;
        uint64_t dma; /* Physical address of mbuf data buffer */
        uint32_t staterr;
        uint32_t hlen_type_rss;
        uint16_t rx_id;
        uint16_t nb_rx;
        uint16_t nb_hold;
        uint16_t data_len;
        uint16_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;

        /*
         * Retrieve RX context of current packet, if any.
         */
        first_seg = rxq->pkt_first_seg;
        last_seg = rxq->pkt_last_seg;

        while (nb_rx < nb_pkts) {
        next_desc:
                /*
                 * 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->wb.upper.status_error;
                if (! (staterr & rte_cpu_to_le_32(IXGBE_RXDADV_STAT_DD)))
                        break;
                rxd = *rxdp;

                /*
                 * Descriptor done.
                 *
                 * 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 does 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, "\nport_id=%u queue_id=%u rx_id=%u "
                           "staterr=0x%x data_len=%u\n",
                           (unsigned) rxq->port_id, (unsigned) rxq->queue_id,
                           (unsigned) rx_id, (unsigned) staterr,
                           (unsigned) rte_le_to_cpu_16(rxd.wb.upper.length));

                nmb = rte_rxmbuf_alloc(rxq->mb_pool);
                if (nmb == NULL) {
                        PMD_RX_LOG(DEBUG, "RX mbuf alloc failed port_id=%u "
                                   "queue_id=%u\n", (unsigned) rxq->port_id,
                                   (unsigned) rxq->queue_id);
                        rte_eth_devices[rxq->port_id].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_ixgbe_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_ixgbe_prefetch(&rx_ring[rx_id]);
                        rte_ixgbe_prefetch(&sw_ring[rx_id]);
                }

                /*
                 * Update RX descriptor with the physical address of the new
                 * data buffer of the new allocated mbuf.
                 */
                rxm = rxe->mbuf;
                rxe->mbuf = nmb;
                dma = rte_cpu_to_le_64(RTE_MBUF_DATA_DMA_ADDR_DEFAULT(nmb));
                rxdp->read.hdr_addr = dma;
                rxdp->read.pkt_addr = dma;

                /*
                 * Set data length & data buffer address of mbuf.
                 */
                data_len = rte_le_to_cpu_16(rxd.wb.upper.length);
                rxm->pkt.data_len = data_len;
                rxm->pkt.data = (char*) rxm->buf_addr + RTE_PKTMBUF_HEADROOM;

                /*
                 * If this is the first buffer of the received packet,
                 * set the pointer to the first mbuf of the packet and
                 * initialize its context.
                 * Otherwise, update the total length and the number of segments
                 * of the current scattered packet, and update the pointer to
                 * the last mbuf of the current packet.
                 */
                if (first_seg == NULL) {
                        first_seg = rxm;
                        first_seg->pkt.pkt_len = data_len;
                        first_seg->pkt.nb_segs = 1;
                } else {
                        first_seg->pkt.pkt_len = (uint16_t)(first_seg->pkt.pkt_len
                                        + data_len);
                        first_seg->pkt.nb_segs++;
                        last_seg->pkt.next = rxm;
                }

                /*
                 * If this is not the last buffer of the received packet,
                 * update the pointer to the last mbuf of the current scattered
                 * packet and continue to parse the RX ring.
                 */
                if (! (staterr & IXGBE_RXDADV_STAT_EOP)) {
                        last_seg = rxm;
                        goto next_desc;
                }

                /*
                 * This is the last buffer of the received packet.
                 * If the CRC is not stripped by the hardware:
                 *   - Subtract the CRC length from the total packet length.
                 *   - If the last buffer only contains the whole CRC or a part
                 *     of it, free the mbuf associated to the last buffer.
                 *     If part of the CRC is also contained in the previous
                 *     mbuf, subtract the length of that CRC part from the
                 *     data length of the previous mbuf.
                 */
                rxm->pkt.next = NULL;
                if (unlikely(rxq->crc_len > 0)) {
                        first_seg->pkt.pkt_len -= ETHER_CRC_LEN;
                        if (data_len <= ETHER_CRC_LEN) {
                                rte_pktmbuf_free_seg(rxm);
                                first_seg->pkt.nb_segs--;
                                last_seg->pkt.data_len = (uint16_t)
                                        (last_seg->pkt.data_len -
                                         (ETHER_CRC_LEN - data_len));
                                last_seg->pkt.next = NULL;
                        } else
                                rxm->pkt.data_len =
                                        (uint16_t) (data_len - ETHER_CRC_LEN);
                }

                /*
                 * Initialize the first mbuf of the returned packet:
                 *    - RX port identifier,
                 *    - hardware offload data, if any:
                 *      - RSS flag & hash,
                 *      - IP checksum flag,
                 *      - VLAN TCI, if any,
                 *      - error flags.
                 */
                first_seg->pkt.in_port = rxq->port_id;

                /*
                 * The vlan_tci field is only valid when PKT_RX_VLAN_PKT is
                 * set in the pkt_flags field.
                 */
                first_seg->pkt.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(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));
                first_seg->ol_flags = pkt_flags;

                if (likely(pkt_flags & PKT_RX_RSS_HASH))
                        first_seg->pkt.hash.rss = rxd.wb.lower.hi_dword.rss;
                else if (pkt_flags & PKT_RX_FDIR) {
                        first_seg->pkt.hash.fdir.hash =
                                (uint16_t)((rxd.wb.lower.hi_dword.csum_ip.csum)
                                           & IXGBE_ATR_HASH_MASK);
                        first_seg->pkt.hash.fdir.id =
                                rxd.wb.lower.hi_dword.csum_ip.ip_id;
                }

                /* Prefetch data of first segment, if configured to do so. */
                rte_packet_prefetch(first_seg->pkt.data);

                /*
                 * Store the mbuf address into the next entry of the array
                 * of returned packets.
                 */
                rx_pkts[nb_rx++] = first_seg;

                /*
                 * Setup receipt context for a new packet.
                 */
                first_seg = NULL;
        }

        /*
         * Record index of the next RX descriptor to probe.
         */
        rxq->rx_tail = rx_id;

        /*
         * Save receive context.
         */
        rxq->pkt_first_seg = first_seg;
        rxq->pkt_last_seg = last_seg;

        /*
         * If the number of free RX descriptors is greater than the RX free
         * threshold of the queue, advance the Receive Descriptor Tail (RDT)
         * register.
         * Update the RDT with the value of the last processed RX descriptor
         * minus 1, to guarantee that the RDT register is never equal to the
         * RDH register, which creates a "full" ring situtation 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\n",
                           (unsigned) rxq->port_id, (unsigned) rxq->queue_id,
                           (unsigned) rx_id, (unsigned) nb_hold,
                           (unsigned) nb_rx);
                rx_id = (uint16_t) ((rx_id == 0) ?
                                     (rxq->nb_rx_desc - 1) : (rx_id - 1));
                IXGBE_PCI_REG_WRITE(rxq->rdt_reg_addr, rx_id);
                nb_hold = 0;
        }
        rxq->nb_rx_hold = nb_hold;
        return (nb_rx);
}

/*********************************************************************
 *
 *  Queue management functions
 *
 **********************************************************************/

/*
 * Rings setup and release.
 *
 * TDBA/RDBA should be aligned on 16 byte boundary. But TDLEN/RDLEN should be
 * multiple of 128 bytes. So we align TDBA/RDBA on 128 byte boundary. This will
 * also optimize cache line size effect. H/W supports up to cache line size 128.
 */
#define IXGBE_ALIGN 128

/*
 * Maximum number of Ring Descriptors.
 *
 * Since RDLEN/TDLEN should be multiple of 128 bytes, the number of ring
 * descriptors should meet the following condition:
 *      (num_ring_desc * sizeof(rx/tx descriptor)) % 128 == 0
 */
#define IXGBE_MIN_RING_DESC 64
#define IXGBE_MAX_RING_DESC 4096

/*
 * Create memzone for HW rings. malloc can't be used as the physical address is
 * needed. If the memzone is already created, then this function returns a ptr
 * to the old one.
 */
static const struct rte_memzone *
ring_dma_zone_reserve(struct rte_eth_dev *dev, const char *ring_name,
                      uint16_t queue_id, uint32_t ring_size, int socket_id)
{
        char z_name[RTE_MEMZONE_NAMESIZE];
        const struct rte_memzone *mz;

        rte_snprintf(z_name, sizeof(z_name), "%s_%s_%d_%d",
                        dev->driver->pci_drv.name, ring_name,
                        dev->data->port_id, queue_id);

        mz = rte_memzone_lookup(z_name);
        if (mz)
                return mz;

        return rte_memzone_reserve_aligned(z_name, (uint64_t) ring_size,
                        socket_id, 0, IXGBE_ALIGN);
}

static void
ixgbe_tx_queue_release_mbufs(struct igb_tx_queue *txq)
{
        unsigned i;

        if (txq->sw_ring != NULL) {
                for (i = 0; i < txq->nb_tx_desc; i++) {
                        if (txq->sw_ring[i].mbuf != NULL) {
                                rte_pktmbuf_free_seg(txq->sw_ring[i].mbuf);
                                txq->sw_ring[i].mbuf = NULL;
                        }
                }
        }
}

static void
ixgbe_tx_queue_release(struct igb_tx_queue *txq)
{
        if (txq != NULL) {
        ixgbe_tx_queue_release_mbufs(txq);
        rte_free(txq->sw_ring);
        rte_free(txq);
        }
}

void
ixgbe_dev_tx_queue_release(void *txq)
{
        ixgbe_tx_queue_release(txq);
}

/* (Re)set dynamic igb_tx_queue fields to defaults */
static void
ixgbe_reset_tx_queue(struct igb_tx_queue *txq)
{
        struct igb_tx_entry *txe = txq->sw_ring;
        uint16_t prev, i;

        /* Zero out HW ring memory */
        for (i = 0; i < sizeof(union ixgbe_adv_tx_desc) * txq->nb_tx_desc; i++) {
                ((volatile char *)txq->tx_ring)[i] = 0;
        }

        /* Initialize SW ring entries */
        prev = (uint16_t) (txq->nb_tx_desc - 1);
        for (i = 0; i < txq->nb_tx_desc; i++) {
                volatile union ixgbe_adv_tx_desc *txd = &txq->tx_ring[i];
                txd->wb.status = IXGBE_TXD_STAT_DD;
                txe[i].mbuf = NULL;
                txe[i].last_id = i;
                txe[prev].next_id = i;
                prev = i;
        }

        txq->tx_tail = 0;
        txq->nb_tx_used = 0;
        /*
         * Always allow 1 descriptor to be un-allocated to avoid
         * a H/W race condition
         */
        txq->last_desc_cleaned = (uint16_t)(txq->nb_tx_desc - 1);
        txq->nb_tx_free = (uint16_t)(txq->nb_tx_desc - 1);
        txq->ctx_curr = 0;
        memset((void*)&txq->ctx_cache, 0,
                IXGBE_CTX_NUM * sizeof(struct ixgbe_advctx_info));
}

int
ixgbe_dev_tx_queue_setup(struct rte_eth_dev *dev,
                         uint16_t queue_idx,
                         uint16_t nb_desc,
                         unsigned int socket_id,
                         const struct rte_eth_txconf *tx_conf)
{
        const struct rte_memzone *tz;
        struct igb_tx_queue *txq;
        struct ixgbe_hw     *hw;
        uint16_t tx_rs_thresh, tx_free_thresh;

        PMD_INIT_FUNC_TRACE();
        hw = IXGBE_DEV_PRIVATE_TO_HW(dev->data->dev_private);

        /*
         * Validate number of transmit descriptors.
         * It must not exceed hardware maximum, and must be multiple
         * of IXGBE_ALIGN.
         */
        if (((nb_desc * sizeof(union ixgbe_adv_tx_desc)) % IXGBE_ALIGN) != 0 ||
            (nb_desc > IXGBE_MAX_RING_DESC) ||
            (nb_desc < IXGBE_MIN_RING_DESC)) {
                return -EINVAL;
        }

        /*
         * The following two parameters control the setting of the RS bit on
         * transmit descriptors.
         * TX descriptors will have their RS bit set after txq->tx_rs_thresh
         * descriptors have been used.
         * The TX descriptor ring will be cleaned after txq->tx_free_thresh
         * descriptors are used or if the number of descriptors required
         * to transmit a packet is greater than the number of free TX
         * descriptors.
         * The following constraints must be satisfied:
         *  tx_rs_thresh must be greater than 0.
         *  tx_rs_thresh must be less than the size of the ring minus 2.
         *  tx_rs_thresh must be less than or equal to tx_free_thresh.
         *  tx_free_thresh must be greater than 0.
         *  tx_free_thresh must be less than the size of the ring minus 3.
         * One descriptor in the TX ring is used as a sentinel to avoid a
         * H/W race condition, hence the maximum threshold constraints.
         * When set to zero use default values.
         */
        tx_rs_thresh = (tx_conf->tx_rs_thresh) ?
                        tx_conf->tx_rs_thresh : DEFAULT_TX_RS_THRESH;
        tx_free_thresh = (tx_conf->tx_free_thresh) ?
                        tx_conf->tx_free_thresh : DEFAULT_TX_FREE_THRESH;
        if (tx_rs_thresh >= (nb_desc - 2)) {
                RTE_LOG(ERR, PMD,
                             "tx_rs_thresh must be less than the "
                             "number of TX descriptors minus 2. "
                             "(tx_rs_thresh=%u port=%d queue=%d)",
                             tx_rs_thresh, dev->data->port_id, queue_idx);
                return -(EINVAL);
        }
        if (tx_free_thresh >= (nb_desc - 3)) {
                RTE_LOG(ERR, PMD,
                             "tx_rs_thresh must be less than the "
                             "tx_free_thresh must be less than the "
                             "number of TX descriptors minus 3. "
                             "(tx_free_thresh=%u port=%d queue=%d)",
                             tx_free_thresh, dev->data->port_id, queue_idx);
                return -(EINVAL);
        }
        if (tx_rs_thresh > tx_free_thresh) {
                RTE_LOG(ERR, PMD,
                             "tx_rs_thresh must be less than or equal to "
                             "tx_free_thresh. "
                             "(tx_free_thresh=%u tx_rs_thresh=%u "
                             "port=%d queue=%d)",
                             tx_free_thresh, tx_rs_thresh,
                             dev->data->port_id, queue_idx);
                return -(EINVAL);
        }

        /*
         * If rs_bit_thresh is greater than 1, then TX WTHRESH should be
         * set to 0. If WTHRESH is greater than zero, the RS bit is ignored
         * by the NIC and all descriptors are written back after the NIC
         * accumulates WTHRESH descriptors.
         */
        if ((tx_rs_thresh > 1) && (tx_conf->tx_thresh.wthresh != 0)) {
                RTE_LOG(ERR, PMD,
                             "TX WTHRESH should be set to 0 if "
                             "tx_rs_thresh is greater than 1. "
                             "TX WTHRESH will be set to 0. "
                             "(tx_rs_thresh=%u port=%d queue=%d)",
                             tx_rs_thresh,
                             dev->data->port_id, queue_idx);
                return -(EINVAL);
        }

        /* Free memory prior to re-allocation if needed... */
        if (dev->data->tx_queues[queue_idx] != NULL)
                ixgbe_tx_queue_release(dev->data->tx_queues[queue_idx]);

        /* First allocate the tx queue data structure */
        txq = rte_zmalloc("ethdev TX queue", sizeof(struct igb_tx_queue),
                          CACHE_LINE_SIZE);
        if (txq == NULL)
                return (-ENOMEM);

        /*
         * Allocate TX ring hardware descriptors. A memzone large enough to
         * handle the maximum ring size is allocated in order to allow for
         * resizing in later calls to the queue setup function.
         */
        tz = ring_dma_zone_reserve(dev, "tx_ring", queue_idx,
                        sizeof(union ixgbe_adv_tx_desc) * IXGBE_MAX_RING_DESC,
                        socket_id);
        if (tz == NULL) {
                ixgbe_tx_queue_release(txq);
                return (-ENOMEM);
        }

        txq->nb_tx_desc = nb_desc;
        txq->tx_rs_thresh = tx_rs_thresh;
        txq->tx_free_thresh = tx_free_thresh;
        txq->pthresh = tx_conf->tx_thresh.pthresh;
        txq->hthresh = tx_conf->tx_thresh.hthresh;
        txq->wthresh = tx_conf->tx_thresh.wthresh;
        txq->queue_id = queue_idx;
        txq->port_id = dev->data->port_id;

        /*
         * Modification to set VFTDT for virtual function if vf is detected
         */
        if (hw->mac.type == ixgbe_mac_82599_vf)
                txq->tdt_reg_addr = IXGBE_PCI_REG_ADDR(hw, IXGBE_VFTDT(queue_idx));
        else
                txq->tdt_reg_addr = IXGBE_PCI_REG_ADDR(hw, IXGBE_TDT(queue_idx));

        txq->tx_ring_phys_addr = (uint64_t) tz->phys_addr;
        txq->tx_ring = (union ixgbe_adv_tx_desc *) tz->addr;

        /* Allocate software ring */
        txq->sw_ring = rte_zmalloc("txq->sw_ring",
                                   sizeof(struct igb_tx_entry) * nb_desc,
                                   CACHE_LINE_SIZE);
        if (txq->sw_ring == NULL) {
                ixgbe_tx_queue_release(txq);
                return (-ENOMEM);
        }
        PMD_INIT_LOG(DEBUG, "sw_ring=%p hw_ring=%p dma_addr=0x%"PRIx64"\n",
                     txq->sw_ring, txq->tx_ring, txq->tx_ring_phys_addr);

        ixgbe_reset_tx_queue(txq);

        dev->data->tx_queues[queue_idx] = txq;

        dev->tx_pkt_burst = ixgbe_xmit_pkts;

        return (0);
}

static void
ixgbe_rx_queue_release_mbufs(struct igb_rx_queue *rxq)
{
        unsigned i;

        if (rxq->sw_ring != NULL) {
                for (i = 0; i < rxq->nb_rx_desc; i++) {
                        if (rxq->sw_ring[i].mbuf != NULL) {
                                rte_pktmbuf_free_seg(rxq->sw_ring[i].mbuf);
                                rxq->sw_ring[i].mbuf = NULL;
                        }
                }
#ifdef RTE_LIBRTE_IXGBE_RX_ALLOW_BULK_ALLOC
                if (rxq->rx_nb_avail) {
                        for (i = 0; i < rxq->rx_nb_avail; ++i) {
                                struct rte_mbuf *mb;
                                mb = rxq->rx_stage[rxq->rx_next_avail + i];
                                rte_pktmbuf_free_seg(mb);
                        }
                        rxq->rx_nb_avail = 0;
                }
#endif
        }
}

static void
ixgbe_rx_queue_release(struct igb_rx_queue *rxq)
{
        ixgbe_rx_queue_release_mbufs(rxq);
        rte_free(rxq->sw_ring);
        rte_free(rxq);
}

void
ixgbe_dev_rx_queue_release(void *rxq)
{
        ixgbe_rx_queue_release(rxq);
}

/*
 * Check if Rx Burst Bulk Alloc function can be used.
 * Return
 *        0: the preconditions are satisfied and the bulk allocation function
 *           can be used.
 *  -EINVAL: the preconditions are NOT satisfied and the default Rx burst
 *           function must be used.
 */
static inline int
check_rx_burst_bulk_alloc_preconditions(struct igb_rx_queue *rxq)
{
        int ret = 0;

        /*
         * Make sure the following pre-conditions are satisfied:
         *   rxq->rx_free_thresh >= RTE_PMD_IXGBE_RX_MAX_BURST
         *   rxq->rx_free_thresh < rxq->nb_rx_desc
         *   (rxq->nb_rx_desc % rxq->rx_free_thresh) == 0
         *   rxq->nb_rx_desc<(IXGBE_MAX_RING_DESC-RTE_PMD_IXGBE_RX_MAX_BURST)
         * Scattered packets are not supported.  This should be checked
         * outside of this function.
         */
#ifdef RTE_LIBRTE_IXGBE_RX_ALLOW_BULK_ALLOC
        if (! (rxq->rx_free_thresh >= RTE_PMD_IXGBE_RX_MAX_BURST))
                ret = -EINVAL;
        else if (! (rxq->rx_free_thresh < rxq->nb_rx_desc))
                ret = -EINVAL;
        else if (! ((rxq->nb_rx_desc % rxq->rx_free_thresh) == 0))
                ret = -EINVAL;
        else if (! (rxq->nb_rx_desc <
               (IXGBE_MAX_RING_DESC - RTE_PMD_IXGBE_RX_MAX_BURST)))
                ret = -EINVAL;
#else
        ret = -EINVAL;
#endif

        return ret;
}

/* (Re)set dynamic igb_rx_queue fields to defaults */
static void
ixgbe_reset_rx_queue(struct igb_rx_queue *rxq)
{
        unsigned i;

        /*
         * By default, the Rx queue setup function allocates enough memory for
         * IXGBE_MAX_RING_DESC.  The Rx Burst bulk allocation function requires
         * extra memory at the end of the descriptor ring to be zero'd out. A
         * pre-condition for using the Rx burst bulk alloc function is that the
         * number of descriptors is less than or equal to
         * (IXGBE_MAX_RING_DESC - RTE_PMD_IXGBE_RX_MAX_BURST). Check all the
         * constraints here to see if we need to zero out memory after the end
         * of the H/W descriptor ring.
         */
#ifdef RTE_LIBRTE_IXGBE_RX_ALLOW_BULK_ALLOC
        if (check_rx_burst_bulk_alloc_preconditions(rxq) == 0)
                /* zero out extra memory */
                len = rxq->nb_rx_desc + RTE_PMD_IXGBE_RX_MAX_BURST;
        else
#endif
                /* do not zero out extra memory */
                len = rxq->nb_rx_desc;

        /*
         * Zero out HW ring memory. Zero out extra memory at the end of
         * the H/W ring so look-ahead logic in Rx Burst bulk alloc function
         * reads extra memory as zeros.
         */
        for (i = 0; i < len * sizeof(union ixgbe_adv_rx_desc); i++) {
                ((volatile char *)rxq->rx_ring)[i] = 0;
        }

#ifdef RTE_LIBRTE_IXGBE_RX_ALLOW_BULK_ALLOC
        /*
         * initialize extra software ring entries. Space for these extra
         * entries is always allocated
         */
        memset(&rxq->fake_mbuf, 0x0, sizeof(rxq->fake_mbuf));
        for (i = 0; i < RTE_PMD_IXGBE_RX_MAX_BURST; ++i) {
                rxq->sw_ring[rxq->nb_rx_desc + i].mbuf = &rxq->fake_mbuf;
        }

        rxq->rx_nb_avail = 0;
        rxq->rx_next_avail = 0;
        rxq->rx_free_trigger = rxq->rx_free_thresh - 1;
#endif /* RTE_LIBRTE_IXGBE_RX_ALLOW_BULK_ALLOC */
        rxq->rx_tail = 0;
        rxq->nb_rx_hold = 0;
        rxq->pkt_first_seg = NULL;
        rxq->pkt_last_seg = NULL;
}

int
ixgbe_dev_rx_queue_setup(struct rte_eth_dev *dev,
                         uint16_t queue_idx,
                         uint16_t nb_desc,
                         unsigned int socket_id,
                         const struct rte_eth_rxconf *rx_conf,
                         struct rte_mempool *mp)
{
        const struct rte_memzone *rz;
        struct igb_rx_queue *rxq;
        struct ixgbe_hw     *hw;

        PMD_INIT_FUNC_TRACE();
        hw = IXGBE_DEV_PRIVATE_TO_HW(dev->data->dev_private);

        /*
         * Validate number of receive descriptors.
         * It must not exceed hardware maximum, and must be multiple
         * of IXGBE_ALIGN.
         */
        if (((nb_desc * sizeof(union ixgbe_adv_rx_desc)) % IXGBE_ALIGN) != 0 ||
            (nb_desc > IXGBE_MAX_RING_DESC) ||
            (nb_desc < IXGBE_MIN_RING_DESC)) {
                return (-EINVAL);
        }

        /* Free memory prior to re-allocation if needed... */
        if (dev->data->rx_queues[queue_idx] != NULL)
                ixgbe_rx_queue_release(dev->data->rx_queues[queue_idx]);

        /* First allocate the rx queue data structure */
        rxq = rte_zmalloc("ethdev RX queue", sizeof(struct igb_rx_queue),
                          CACHE_LINE_SIZE);
        if (rxq == NULL)
                return (-ENOMEM);
        rxq->mb_pool = mp;
        rxq->nb_rx_desc = nb_desc;
        rxq->rx_free_thresh = rx_conf->rx_free_thresh;
        rxq->queue_id = queue_idx;
        rxq->port_id = dev->data->port_id;
        rxq->crc_len = (uint8_t) ((dev->data->dev_conf.rxmode.hw_strip_crc) ? 0 :
                                  ETHER_CRC_LEN);

        /*
         * Allocate TX ring hardware descriptors. A memzone large enough to
         * handle the maximum ring size is allocated in order to allow for
         * resizing in later calls to the queue setup function.
         */
        rz = ring_dma_zone_reserve(dev, "rx_ring", queue_idx,
                        IXGBE_MAX_RING_DESC * sizeof(union ixgbe_adv_rx_desc),
                        socket_id);
        if (rz == NULL) {
                ixgbe_rx_queue_release(rxq);
                return (-ENOMEM);
        }
        /*
         * Modified to setup VFRDT for Virtual Function
         */
        if (hw->mac.type == ixgbe_mac_82599_vf)
                rxq->rdt_reg_addr = IXGBE_PCI_REG_ADDR(hw, IXGBE_VFRDT(queue_idx));
        else
                rxq->rdt_reg_addr = IXGBE_PCI_REG_ADDR(hw, IXGBE_RDT(queue_idx));

        rxq->rx_ring_phys_addr = (uint64_t) rz->phys_addr;
        rxq->rx_ring = (union ixgbe_adv_rx_desc *) rz->addr;

        /*
         * Allocate software ring. Allow for space at the end of the 
         * S/W ring to make sure look-ahead logic in bulk alloc Rx burst
         * function does not access an invalid memory region.
         */
#ifdef RTE_LIBRTE_IXGBE_RX_ALLOW_BULK_ALLOC
        len = nb_desc + RTE_PMD_IXGBE_RX_MAX_BURST;
#else
        len = nb_desc;
#endif
        rxq->sw_ring = rte_zmalloc("rxq->sw_ring",
                                   sizeof(struct igb_rx_entry) * nb_desc,
                                   CACHE_LINE_SIZE);
        if (rxq->sw_ring == NULL) {
                ixgbe_rx_queue_release(rxq);
                return (-ENOMEM);
        }
        PMD_INIT_LOG(DEBUG, "sw_ring=%p hw_ring=%p dma_addr=0x%"PRIx64"\n",
                     rxq->sw_ring, rxq->rx_ring, rxq->rx_ring_phys_addr);

        /*
         * Certain constaints must be met in order to use the bulk buffer
         * allocation Rx burst function.
         */
        use_def_burst_func = check_rx_burst_bulk_alloc_preconditions(rxq);

        /* Check if pre-conditions are satisfied, and no Scattered Rx */
        if (!use_def_burst_func && !dev->data->scattered_rx) {
#ifdef RTE_LIBRTE_IXGBE_RX_ALLOW_BULK_ALLOC
                PMD_INIT_LOG(DEBUG, "Rx Burst Bulk Alloc Preconditions are "
                             "satisfied. Rx Burst Bulk Alloc function will be "
                             "used on port=%d, queue=%d.\n",
                             rxq->port_id, rxq->queue_id);
                dev->rx_pkt_burst = ixgbe_recv_pkts_bulk_alloc;
#endif
        } else {
                PMD_INIT_LOG(DEBUG, "Rx Burst Bulk Alloc Preconditions "
                             "are not satisfied, Scattered Rx is requested, "
                             "or RTE_LIBRTE_IXGBE_RX_ALLOW_BULK_ALLOC is not "
                             "enabled (port=%d, queue=%d).\n",
                             rxq->port_id, rxq->queue_id);
        }
        dev->data->rx_queues[queue_idx] = rxq;

        ixgbe_reset_rx_queue(rxq);

        return 0;
}

void
ixgbe_dev_clear_queues(struct rte_eth_dev *dev)
{
        unsigned i;


        for (i = 0; i < dev->data->nb_tx_queues; i++) {
                struct igb_tx_queue *txq = dev->data->tx_queues[i];
                ixgbe_tx_queue_release_mbufs(txq);
                ixgbe_reset_tx_queue(txq);
        }

        for (i = 0; i < dev->data->nb_rx_queues; i++) {
                struct igb_rx_queue *rxq = dev->data->rx_queues[i];
                ixgbe_rx_queue_release_mbufs(rxq);
                ixgbe_reset_rx_queue(rxq);
        }
}

/*********************************************************************
 *
 *  Device RX/TX init functions
 *
 **********************************************************************/

/**
 * Receive Side Scaling (RSS)
 * See section 7.1.2.8 in the following document:
 *     "Intel 82599 10 GbE Controller Datasheet" - Revision 2.1 October 2009
 *
 * Principles:
 * The source and destination IP addresses of the IP header and the source
 * and destination ports of TCP/UDP headers, if any, of received packets are
 * hashed against a configurable random key to compute a 32-bit RSS hash result.
 * The seven (7) LSBs of the 32-bit hash result are used as an index into a
 * 128-entry redirection table (RETA).  Each entry of the RETA provides a 3-bit
 * RSS output index which is used as the RX queue index where to store the
 * received packets.
 * The following output is supplied in the RX write-back descriptor:
 *     - 32-bit result of the Microsoft RSS hash function,
 *     - 4-bit RSS type field.
 */

/*
 * RSS random key supplied in section 7.1.2.8.3 of the Intel 82599 datasheet.
 * Used as the default key.
 */
static uint8_t rss_intel_key[40] = {
        0x6D, 0x5A, 0x56, 0xDA, 0x25, 0x5B, 0x0E, 0xC2,
        0x41, 0x67, 0x25, 0x3D, 0x43, 0xA3, 0x8F, 0xB0,
        0xD0, 0xCA, 0x2B, 0xCB, 0xAE, 0x7B, 0x30, 0xB4,
        0x77, 0xCB, 0x2D, 0xA3, 0x80, 0x30, 0xF2, 0x0C,
        0x6A, 0x42, 0xB7, 0x3B, 0xBE, 0xAC, 0x01, 0xFA,
};

static void
ixgbe_rss_disable(struct rte_eth_dev *dev)
{
        struct ixgbe_hw *hw;
        uint32_t mrqc;

        hw = IXGBE_DEV_PRIVATE_TO_HW(dev->data->dev_private);
        mrqc = IXGBE_READ_REG(hw, IXGBE_MRQC);
        mrqc &= ~IXGBE_MRQC_RSSEN;
        IXGBE_WRITE_REG(hw, IXGBE_MRQC, mrqc);
}

static void
ixgbe_rss_configure(struct rte_eth_dev *dev)
{
        struct ixgbe_hw *hw;
        uint8_t *hash_key;
        uint32_t rss_key;
        uint32_t mrqc;
        uint32_t reta;
        uint16_t rss_hf;
        uint16_t i;
        uint16_t j;

        PMD_INIT_FUNC_TRACE();
        hw = IXGBE_DEV_PRIVATE_TO_HW(dev->data->dev_private);

        rss_hf = dev->data->dev_conf.rx_adv_conf.rss_conf.rss_hf;
        if (rss_hf == 0) { /* Disable RSS */
                ixgbe_rss_disable(dev);
                return;
        }
        hash_key = dev->data->dev_conf.rx_adv_conf.rss_conf.rss_key;
        if (hash_key == NULL)
                hash_key = rss_intel_key; /* Default hash key */

        /* Fill in RSS hash key */
        for (i = 0; i < 10; i++) {
                rss_key  = hash_key[(i * 4)];
                rss_key |= hash_key[(i * 4) + 1] << 8;
                rss_key |= hash_key[(i * 4) + 2] << 16;
                rss_key |= hash_key[(i * 4) + 3] << 24;
                IXGBE_WRITE_REG_ARRAY(hw, IXGBE_RSSRK(0), i, rss_key);
        }

        /* Fill in redirection table */
        reta = 0;
        for (i = 0, j = 0; i < 128; i++, j++) {
                if (j == dev->data->nb_rx_queues) j = 0;
                reta = (reta << 8) | j;
                if ((i & 3) == 3)
                        IXGBE_WRITE_REG(hw, IXGBE_RETA(i >> 2), rte_bswap32(reta));
        }

        /* Set configured hashing functions in MRQC register */
        mrqc = IXGBE_MRQC_RSSEN; /* RSS enable */
        if (rss_hf & ETH_RSS_IPV4)
                mrqc |= IXGBE_MRQC_RSS_FIELD_IPV4;
        if (rss_hf & ETH_RSS_IPV4_TCP)
                mrqc |= IXGBE_MRQC_RSS_FIELD_IPV4_TCP;
        if (rss_hf & ETH_RSS_IPV6)
                mrqc |= IXGBE_MRQC_RSS_FIELD_IPV6;
        if (rss_hf & ETH_RSS_IPV6_EX)
                mrqc |= IXGBE_MRQC_RSS_FIELD_IPV6_EX;
        if (rss_hf & ETH_RSS_IPV6_TCP)
                mrqc |= IXGBE_MRQC_RSS_FIELD_IPV6_TCP;
        if (rss_hf & ETH_RSS_IPV6_TCP_EX)
                mrqc |= IXGBE_MRQC_RSS_FIELD_IPV6_EX_TCP;
        if (rss_hf & ETH_RSS_IPV4_UDP)
                mrqc |= IXGBE_MRQC_RSS_FIELD_IPV4_UDP;
        if (rss_hf & ETH_RSS_IPV6_UDP)
                mrqc |= IXGBE_MRQC_RSS_FIELD_IPV6_UDP;
        if (rss_hf & ETH_RSS_IPV6_UDP_EX)
                mrqc |= IXGBE_MRQC_RSS_FIELD_IPV6_EX_UDP;
        IXGBE_WRITE_REG(hw, IXGBE_MRQC, mrqc);
}

#define NUM_VFTA_REGISTERS 128
#define NIC_RX_BUFFER_SIZE 0x200

static void
ixgbe_vmdq_dcb_configure(struct rte_eth_dev *dev)
{
        struct rte_eth_vmdq_dcb_conf *cfg;
        struct ixgbe_hw *hw;
        enum rte_eth_nb_pools num_pools;
        uint32_t mrqc, vt_ctl, queue_mapping, vlanctrl;
        uint16_t pbsize;
        uint8_t nb_tcs; /* number of traffic classes */
        int i;

        PMD_INIT_FUNC_TRACE();
        hw = IXGBE_DEV_PRIVATE_TO_HW(dev->data->dev_private);
        cfg = &dev->data->dev_conf.rx_adv_conf.vmdq_dcb_conf;
        num_pools = cfg->nb_queue_pools;
        /* Check we have a valid number of pools */
        if (num_pools != ETH_16_POOLS && num_pools != ETH_32_POOLS) {
                ixgbe_rss_disable(dev);
                return;
        }
        /* 16 pools -> 8 traffic classes, 32 pools -> 4 traffic classes */
        nb_tcs = (uint8_t)(ETH_VMDQ_DCB_NUM_QUEUES / (int)num_pools);

        /*
         * RXPBSIZE
         * split rx buffer up into sections, each for 1 traffic class
         */
        pbsize = (uint16_t)(NIC_RX_BUFFER_SIZE / nb_tcs);
        for (i = 0 ; i < nb_tcs; i++) {
                uint32_t rxpbsize = IXGBE_READ_REG(hw, IXGBE_RXPBSIZE(i));
                rxpbsize &= (~(0x3FF << IXGBE_RXPBSIZE_SHIFT));
                /* clear 10 bits. */
                rxpbsize |= (pbsize << IXGBE_RXPBSIZE_SHIFT); /* set value */
                IXGBE_WRITE_REG(hw, IXGBE_RXPBSIZE(i), rxpbsize);
        }
        /* zero alloc all unused TCs */
        for (i = nb_tcs; i < ETH_DCB_NUM_USER_PRIORITIES; i++) {
                uint32_t rxpbsize = IXGBE_READ_REG(hw, IXGBE_RXPBSIZE(i));
                rxpbsize &= (~( 0x3FF << IXGBE_RXPBSIZE_SHIFT ));
                /* clear 10 bits. */
                IXGBE_WRITE_REG(hw, IXGBE_RXPBSIZE(i), rxpbsize);
        }

        /* MRQC: enable vmdq and dcb */
        mrqc = ((num_pools == ETH_16_POOLS) ? \
                IXGBE_MRQC_VMDQRT8TCEN : IXGBE_MRQC_VMDQRT4TCEN );
        IXGBE_WRITE_REG(hw, IXGBE_MRQC, mrqc);

        /* PFVTCTL: turn on virtualisation and set the default pool */
        vt_ctl = IXGBE_VT_CTL_VT_ENABLE | IXGBE_VT_CTL_REPLEN;
        if (cfg->enable_default_pool) {
                vt_ctl |= (cfg->default_pool << IXGBE_VT_CTL_POOL_SHIFT);
        } else {
                vt_ctl |= IXGBE_VT_CTL_DIS_DEFPL;
        }
        IXGBE_WRITE_REG(hw, IXGBE_VT_CTL, vt_ctl);

        /* RTRUP2TC: mapping user priorities to traffic classes (TCs) */
        queue_mapping = 0;
        for (i = 0; i < ETH_DCB_NUM_USER_PRIORITIES; i++)
                /*
                 * mapping is done with 3 bits per priority,
                 * so shift by i*3 each time
                 */
                queue_mapping |= ((cfg->dcb_queue[i] & 0x07) << (i * 3));

        IXGBE_WRITE_REG(hw, IXGBE_RTRUP2TC, queue_mapping);

        /* RTRPCS: DCB related */
        IXGBE_WRITE_REG(hw, IXGBE_RTRPCS, IXGBE_RMCS_RRM);

        /* VLNCTRL: enable vlan filtering and allow all vlan tags through */
        vlanctrl = IXGBE_READ_REG(hw, IXGBE_VLNCTRL);
        vlanctrl |= IXGBE_VLNCTRL_VFE ; /* enable vlan filters */
        IXGBE_WRITE_REG(hw, IXGBE_VLNCTRL, vlanctrl);

        /* VFTA - enable all vlan filters */
        for (i = 0; i < NUM_VFTA_REGISTERS; i++) {
                IXGBE_WRITE_REG(hw, IXGBE_VFTA(i), 0xFFFFFFFF);
        }

        /* VFRE: pool enabling for receive - 16 or 32 */
        IXGBE_WRITE_REG(hw, IXGBE_VFRE(0), \
                        num_pools == ETH_16_POOLS ? 0xFFFF : 0xFFFFFFFF);

        /*
         * MPSAR - allow pools to read specific mac addresses
         * In this case, all pools should be able to read from mac addr 0
         */
        IXGBE_WRITE_REG(hw, IXGBE_MPSAR_LO(0), 0xFFFFFFFF);
        IXGBE_WRITE_REG(hw, IXGBE_MPSAR_HI(0), 0xFFFFFFFF);

        /* PFVLVF, PFVLVFB: set up filters for vlan tags as configured */
        for (i = 0; i < cfg->nb_pool_maps; i++) {
                /* set vlan id in VF register and set the valid bit */
                IXGBE_WRITE_REG(hw, IXGBE_VLVF(i), (IXGBE_VLVF_VIEN | \
                                (cfg->pool_map[i].vlan_id & 0xFFF)));
                /*
                 * Put the allowed pools in VFB reg. As we only have 16 or 32
                 * pools, we only need to use the first half of the register
                 * i.e. bits 0-31
                 */
                IXGBE_WRITE_REG(hw, IXGBE_VLVFB(i*2), cfg->pool_map[i].pools);
        }
}

static int
ixgbe_alloc_rx_queue_mbufs(struct igb_rx_queue *rxq)
{
        struct igb_rx_entry *rxe = rxq->sw_ring;
        uint64_t dma_addr;
        unsigned i;

        /* Initialize software ring entries */
        for (i = 0; i < rxq->nb_rx_desc; i++) {
                volatile union ixgbe_adv_rx_desc *rxd;
                struct rte_mbuf *mbuf = rte_rxmbuf_alloc(rxq->mb_pool);
                if (mbuf == NULL) {
                        PMD_INIT_LOG(ERR, "RX mbuf alloc failed queue_id=%u\n",
                                     (unsigned) rxq->queue_id);
                        return (-ENOMEM);
                }
                dma_addr =
                        rte_cpu_to_le_64(RTE_MBUF_DATA_DMA_ADDR_DEFAULT(mbuf));
                rxd = &rxq->rx_ring[i];
                rxd->read.hdr_addr = dma_addr;
                rxd->read.pkt_addr = dma_addr;
                rxe[i].mbuf = mbuf;
        }

        return 0;
}

/*
 * Initializes Receive Unit.
 */
int
ixgbe_dev_rx_init(struct rte_eth_dev *dev)
{
        struct ixgbe_hw     *hw;
        struct igb_rx_queue *rxq;
        struct rte_pktmbuf_pool_private *mbp_priv;
        uint64_t bus_addr;
        uint32_t rxctrl;
        uint32_t fctrl;
        uint32_t hlreg0;
        uint32_t maxfrs;
        uint32_t srrctl;
        uint32_t rdrxctl;
        uint32_t rxcsum;
        uint16_t buf_size;
        uint16_t i;
        int ret;

        PMD_INIT_FUNC_TRACE();
        hw = IXGBE_DEV_PRIVATE_TO_HW(dev->data->dev_private);

        /*
         * Make sure receives are disabled while setting
         * up the RX context (registers, descriptor rings, etc.).
         */
        rxctrl = IXGBE_READ_REG(hw, IXGBE_RXCTRL);
        IXGBE_WRITE_REG(hw, IXGBE_RXCTRL, rxctrl & ~IXGBE_RXCTRL_RXEN);

        /* Enable receipt of broadcasted frames */
        fctrl = IXGBE_READ_REG(hw, IXGBE_FCTRL);
        fctrl |= IXGBE_FCTRL_BAM;
        fctrl |= IXGBE_FCTRL_DPF;
        fctrl |= IXGBE_FCTRL_PMCF;
        IXGBE_WRITE_REG(hw, IXGBE_FCTRL, fctrl);

        /*
         * Configure CRC stripping, if any.
         */
        hlreg0 = IXGBE_READ_REG(hw, IXGBE_HLREG0);
        if (dev->data->dev_conf.rxmode.hw_strip_crc)
                hlreg0 |= IXGBE_HLREG0_RXCRCSTRP;
        else
                hlreg0 &= ~IXGBE_HLREG0_RXCRCSTRP;

        /*
         * Configure jumbo frame support, if any.
         */
        if (dev->data->dev_conf.rxmode.jumbo_frame == 1) {
                hlreg0 |= IXGBE_HLREG0_JUMBOEN;
                maxfrs = IXGBE_READ_REG(hw, IXGBE_MAXFRS);
                maxfrs &= 0x0000FFFF;
                maxfrs |= (dev->data->dev_conf.rxmode.max_rx_pkt_len << 16);
                IXGBE_WRITE_REG(hw, IXGBE_MAXFRS, maxfrs);
        } else
                hlreg0 &= ~IXGBE_HLREG0_JUMBOEN;

        IXGBE_WRITE_REG(hw, IXGBE_HLREG0, hlreg0);

        /* Setup RX queues */
        for (i = 0; i < dev->data->nb_rx_queues; i++) {
                rxq = dev->data->rx_queues[i];

                /* Allocate buffers for descriptor rings */
                ret = ixgbe_alloc_rx_queue_mbufs(rxq);
                if (ret)
                        return ret;

                /*
                 * Reset crc_len in case it was changed after queue setup by a
                 * call to configure.
                 */
                rxq->crc_len = (uint8_t)
                                ((dev->data->dev_conf.rxmode.hw_strip_crc) ? 0 :
                                ETHER_CRC_LEN);

                /* Setup the Base and Length of the Rx Descriptor Rings */
                bus_addr = rxq->rx_ring_phys_addr;
                IXGBE_WRITE_REG(hw, IXGBE_RDBAL(i),
                                (uint32_t)(bus_addr & 0x00000000ffffffffULL));
                IXGBE_WRITE_REG(hw, IXGBE_RDBAH(i),
                                (uint32_t)(bus_addr >> 32));
                IXGBE_WRITE_REG(hw, IXGBE_RDLEN(i),
                                rxq->nb_rx_desc * sizeof(union ixgbe_adv_rx_desc));
                IXGBE_WRITE_REG(hw, IXGBE_RDH(i), 0);
                IXGBE_WRITE_REG(hw, IXGBE_RDT(i), 0);

                /* Configure the SRRCTL register */
#ifdef RTE_HEADER_SPLIT_ENABLE
                /*
                 * Configure Header Split
                 */
                if (dev->data->dev_conf.rxmode.header_split) {
                        if (hw->mac.type == ixgbe_mac_82599EB) {
                                /* Must setup the PSRTYPE register */
                                uint32_t psrtype;
                                psrtype = IXGBE_PSRTYPE_TCPHDR |
                                        IXGBE_PSRTYPE_UDPHDR   |
                                        IXGBE_PSRTYPE_IPV4HDR  |
                                        IXGBE_PSRTYPE_IPV6HDR;
                                IXGBE_WRITE_REG(hw, IXGBE_PSRTYPE(i), psrtype);
                        }
                        srrctl = ((dev->data->dev_conf.rxmode.split_hdr_size <<
                                   IXGBE_SRRCTL_BSIZEHDRSIZE_SHIFT) &
                                  IXGBE_SRRCTL_BSIZEHDR_MASK);
                        srrctl |= E1000_SRRCTL_DESCTYPE_HDR_SPLIT_ALWAYS;
                } else
#endif
                        srrctl = IXGBE_SRRCTL_DESCTYPE_ADV_ONEBUF;

                /*
                 * Configure the RX buffer size in the BSIZEPACKET field of
                 * the SRRCTL register of the queue.
                 * The value is in 1 KB resolution. Valid values can be from
                 * 1 KB to 16 KB.
                 */
                mbp_priv = (struct rte_pktmbuf_pool_private *)
                        ((char *)rxq->mb_pool + sizeof(struct rte_mempool));
                buf_size = (uint16_t) (mbp_priv->mbuf_data_room_size -
                                       RTE_PKTMBUF_HEADROOM);
                srrctl |= ((buf_size >> IXGBE_SRRCTL_BSIZEPKT_SHIFT) &
                           IXGBE_SRRCTL_BSIZEPKT_MASK);
                IXGBE_WRITE_REG(hw, IXGBE_SRRCTL(i), srrctl);

                buf_size = (uint16_t) ((srrctl & IXGBE_SRRCTL_BSIZEPKT_MASK) <<
                                       IXGBE_SRRCTL_BSIZEPKT_SHIFT);
                if (dev->data->dev_conf.rxmode.max_rx_pkt_len > buf_size){
                        dev->data->scattered_rx = 1;
                        dev->rx_pkt_burst = ixgbe_recv_scattered_pkts;
                }
        }

        /*
         * Configure RSS if device configured with multiple RX queues.
         */
        if (hw->mac.type == ixgbe_mac_82599EB) {
                if (dev->data->nb_rx_queues > 1)
                        switch (dev->data->dev_conf.rxmode.mq_mode) {
                                case ETH_RSS:
                                        ixgbe_rss_configure(dev);
                                        break;

                                case ETH_VMDQ_DCB:
                                        ixgbe_vmdq_dcb_configure(dev);
                                        break;

                                default: ixgbe_rss_disable(dev);
                        }
                else
                        ixgbe_rss_disable(dev);
        }

        /*
         * Setup the Checksum Register.
         * Disable Full-Packet Checksum which is mutually exclusive with RSS.
         * Enable IP/L4 checkum computation by hardware if requested to do so.
         */
        rxcsum = IXGBE_READ_REG(hw, IXGBE_RXCSUM);
        rxcsum |= IXGBE_RXCSUM_PCSD;
        if (dev->data->dev_conf.rxmode.hw_ip_checksum)
                rxcsum |= IXGBE_RXCSUM_IPPCSE;
        else
                rxcsum &= ~IXGBE_RXCSUM_IPPCSE;

        IXGBE_WRITE_REG(hw, IXGBE_RXCSUM, rxcsum);

        if (hw->mac.type == ixgbe_mac_82599EB) {
                rdrxctl = IXGBE_READ_REG(hw, IXGBE_RDRXCTL);
                if (dev->data->dev_conf.rxmode.hw_strip_crc)
                        rdrxctl |= IXGBE_RDRXCTL_CRCSTRIP;
                else
                        rdrxctl &= ~IXGBE_RDRXCTL_CRCSTRIP;
                rdrxctl &= ~IXGBE_RDRXCTL_RSCFRSTSIZE;
                IXGBE_WRITE_REG(hw, IXGBE_RDRXCTL, rdrxctl);
        }

        return 0;
}

/*
 * Initializes Transmit Unit.
 */
void
ixgbe_dev_tx_init(struct rte_eth_dev *dev)
{
        struct ixgbe_hw     *hw;
        struct igb_tx_queue *txq;
        uint64_t bus_addr;
        uint32_t hlreg0;
        uint32_t txctrl;
        uint32_t rttdcs;
        uint16_t i;

        PMD_INIT_FUNC_TRACE();
        hw = IXGBE_DEV_PRIVATE_TO_HW(dev->data->dev_private);

        /* Enable TX CRC (checksum offload requirement) */
        hlreg0 = IXGBE_READ_REG(hw, IXGBE_HLREG0);
        hlreg0 |= IXGBE_HLREG0_TXCRCEN;
        IXGBE_WRITE_REG(hw, IXGBE_HLREG0, hlreg0);

        /* Setup the Base and Length of the Tx Descriptor Rings */
        for (i = 0; i < dev->data->nb_tx_queues; i++) {
                txq = dev->data->tx_queues[i];

                bus_addr = txq->tx_ring_phys_addr;
                IXGBE_WRITE_REG(hw, IXGBE_TDBAL(i),
                                (uint32_t)(bus_addr & 0x00000000ffffffffULL));
                IXGBE_WRITE_REG(hw, IXGBE_TDBAH(i),
                                (uint32_t)(bus_addr >> 32));
                IXGBE_WRITE_REG(hw, IXGBE_TDLEN(i),
                                txq->nb_tx_desc * sizeof(union ixgbe_adv_tx_desc));
                /* Setup the HW Tx Head and TX Tail descriptor pointers */
                IXGBE_WRITE_REG(hw, IXGBE_TDH(i), 0);
                IXGBE_WRITE_REG(hw, IXGBE_TDT(i), 0);

                /*
                 * Disable Tx Head Writeback RO bit, since this hoses
                 * bookkeeping if things aren't delivered in order.
                 */
                switch (hw->mac.type) {
                        case ixgbe_mac_82598EB:
                                txctrl = IXGBE_READ_REG(hw,
                                                        IXGBE_DCA_TXCTRL(i));
                                txctrl &= ~IXGBE_DCA_TXCTRL_TX_WB_RO_EN;
                                IXGBE_WRITE_REG(hw, IXGBE_DCA_TXCTRL(i),
                                                txctrl);
                                break;

                        case ixgbe_mac_82599EB:
                        case ixgbe_mac_X540:
                        default:
                                txctrl = IXGBE_READ_REG(hw,
                                                IXGBE_DCA_TXCTRL_82599(i));
                                txctrl &= ~IXGBE_DCA_TXCTRL_TX_WB_RO_EN;
                                IXGBE_WRITE_REG(hw, IXGBE_DCA_TXCTRL_82599(i),
                                                txctrl);
                                break;
                }
        }

        if (hw->mac.type != ixgbe_mac_82598EB) {
                /* disable arbiter before setting MTQC */
                rttdcs = IXGBE_READ_REG(hw, IXGBE_RTTDCS);
                rttdcs |= IXGBE_RTTDCS_ARBDIS;
                IXGBE_WRITE_REG(hw, IXGBE_RTTDCS, rttdcs);

                IXGBE_WRITE_REG(hw, IXGBE_MTQC, IXGBE_MTQC_64Q_1PB);

                /* re-enable arbiter */
                rttdcs &= ~IXGBE_RTTDCS_ARBDIS;
                IXGBE_WRITE_REG(hw, IXGBE_RTTDCS, rttdcs);
        }
}

/*
 * Start Transmit and Receive Units.
 */
void
ixgbe_dev_rxtx_start(struct rte_eth_dev *dev)
{
        struct ixgbe_hw     *hw;
        struct igb_tx_queue *txq;
        struct igb_rx_queue *rxq;
        uint32_t txdctl;
        uint32_t dmatxctl;
        uint32_t rxdctl;
        uint32_t rxctrl;
        uint16_t i;
        int poll_ms;

        PMD_INIT_FUNC_TRACE();
        hw = IXGBE_DEV_PRIVATE_TO_HW(dev->data->dev_private);

        for (i = 0; i < dev->data->nb_tx_queues; i++) {
                txq = dev->data->tx_queues[i];
                /* Setup Transmit Threshold Registers */
                txdctl = IXGBE_READ_REG(hw, IXGBE_TXDCTL(i));
                txdctl |= txq->pthresh & 0x7F;
                txdctl |= ((txq->hthresh & 0x7F) << 8);
                txdctl |= ((txq->wthresh & 0x7F) << 16);
                IXGBE_WRITE_REG(hw, IXGBE_TXDCTL(i), txdctl);
        }

        if (hw->mac.type != ixgbe_mac_82598EB) {
                dmatxctl = IXGBE_READ_REG(hw, IXGBE_DMATXCTL);
                dmatxctl |= IXGBE_DMATXCTL_TE;
                IXGBE_WRITE_REG(hw, IXGBE_DMATXCTL, dmatxctl);
        }

        for (i = 0; i < dev->data->nb_tx_queues; i++) {
                txdctl = IXGBE_READ_REG(hw, IXGBE_TXDCTL(i));
                txdctl |= IXGBE_TXDCTL_ENABLE;
                IXGBE_WRITE_REG(hw, IXGBE_TXDCTL(i), txdctl);

                /* Wait until TX Enable ready */
                if (hw->mac.type == ixgbe_mac_82599EB) {
                        poll_ms = 10;
                        do {
                                rte_delay_ms(1);
                                txdctl = IXGBE_READ_REG(hw, IXGBE_TXDCTL(i));
                        } while (--poll_ms && !(txdctl & IXGBE_TXDCTL_ENABLE));
                        if (!poll_ms)
                                PMD_INIT_LOG(ERR, "Could not enable "
                                             "Tx Queue %d\n", i);
                }
        }
        for (i = 0; i < dev->data->nb_rx_queues; i++) {
                rxq = dev->data->rx_queues[i];
                rxdctl = IXGBE_READ_REG(hw, IXGBE_RXDCTL(i));
                rxdctl |= IXGBE_RXDCTL_ENABLE;
                IXGBE_WRITE_REG(hw, IXGBE_RXDCTL(i), rxdctl);

                /* Wait until RX Enable ready */
                poll_ms = 10;
                do {
                        rte_delay_ms(1);
                        rxdctl = IXGBE_READ_REG(hw, IXGBE_RXDCTL(i));
                } while (--poll_ms && !(rxdctl & IXGBE_RXDCTL_ENABLE));
                if (!poll_ms)
                        PMD_INIT_LOG(ERR, "Could not enable "
                                     "Rx Queue %d\n", i);
                rte_wmb();
                IXGBE_WRITE_REG(hw, IXGBE_RDT(i), rxq->nb_rx_desc - 1);
        }

        /* Enable Receive engine */
        rxctrl = IXGBE_READ_REG(hw, IXGBE_RXCTRL);
        if (hw->mac.type == ixgbe_mac_82598EB)
                rxctrl |= IXGBE_RXCTRL_DMBYPS;
        rxctrl |= IXGBE_RXCTRL_RXEN;
        hw->mac.ops.enable_rx_dma(hw, rxctrl);
}


/*
 * [VF] Initializes Receive Unit.
 */
int
ixgbevf_dev_rx_init(struct rte_eth_dev *dev)
{
        struct ixgbe_hw     *hw;
        struct igb_rx_queue *rxq;
        struct rte_pktmbuf_pool_private *mbp_priv;
        uint64_t bus_addr;
        uint32_t srrctl;
        uint16_t buf_size;
        uint16_t i;
        int ret;

        PMD_INIT_FUNC_TRACE();
        hw = IXGBE_DEV_PRIVATE_TO_HW(dev->data->dev_private);

        /* Setup RX queues */
        dev->rx_pkt_burst = ixgbe_recv_pkts;
        for (i = 0; i < dev->data->nb_rx_queues; i++) {
                rxq = dev->data->rx_queues[i];

                /* Allocate buffers for descriptor rings */
                ret = ixgbe_alloc_rx_queue_mbufs(rxq);
                if (ret){
                        return -1;
                }
                /* Setup the Base and Length of the Rx Descriptor Rings */
                bus_addr = rxq->rx_ring_phys_addr;

                IXGBE_WRITE_REG(hw, IXGBE_VFRDBAL(i),
                                (uint32_t)(bus_addr & 0x00000000ffffffffULL));
                IXGBE_WRITE_REG(hw, IXGBE_VFRDBAH(i),
                                (uint32_t)(bus_addr >> 32));
                IXGBE_WRITE_REG(hw, IXGBE_VFRDLEN(i),
                                rxq->nb_rx_desc * sizeof(union ixgbe_adv_rx_desc));
                IXGBE_WRITE_REG(hw, IXGBE_VFRDH(i), 0);
                IXGBE_WRITE_REG(hw, IXGBE_VFRDT(i), 0);


                /* Configure the SRRCTL register */
#ifdef RTE_HEADER_SPLIT_ENABLE
                /*
                 * Configure Header Split
                 */
                if (dev->data->dev_conf.rxmode.header_split) {

                        /* Must setup the PSRTYPE register */
                        uint32_t psrtype;
                        psrtype = IXGBE_PSRTYPE_TCPHDR |
                                IXGBE_PSRTYPE_UDPHDR   |
                                IXGBE_PSRTYPE_IPV4HDR  |
                                IXGBE_PSRTYPE_IPV6HDR;

                        IXGBE_WRITE_REG(hw, IXGBE_VFPSRTYPE(i), psrtype);

                        srrctl = ((dev->data->dev_conf.rxmode.split_hdr_size <<
                                   IXGBE_SRRCTL_BSIZEHDRSIZE_SHIFT) &
                                  IXGBE_SRRCTL_BSIZEHDR_MASK);
                        srrctl |= E1000_SRRCTL_DESCTYPE_HDR_SPLIT_ALWAYS;
                } else
#endif
                        srrctl = IXGBE_SRRCTL_DESCTYPE_ADV_ONEBUF;

                /*
                 * Configure the RX buffer size in the BSIZEPACKET field of
                 * the SRRCTL register of the queue.
                 * The value is in 1 KB resolution. Valid values can be from
                 * 1 KB to 16 KB.
                 */
                mbp_priv = (struct rte_pktmbuf_pool_private *)
                        ((char *)rxq->mb_pool + sizeof(struct rte_mempool));
                buf_size = (uint16_t) (mbp_priv->mbuf_data_room_size -
                                       RTE_PKTMBUF_HEADROOM);
                srrctl |= ((buf_size >> IXGBE_SRRCTL_BSIZEPKT_SHIFT) &
                           IXGBE_SRRCTL_BSIZEPKT_MASK);

                /*
                 * VF modification to write virtual function SRRCTL register
                 */
                IXGBE_WRITE_REG(hw, IXGBE_VFSRRCTL(i), srrctl);

                buf_size = (uint16_t) ((srrctl & IXGBE_SRRCTL_BSIZEPKT_MASK) <<
                                       IXGBE_SRRCTL_BSIZEPKT_SHIFT);
                if (dev->data->dev_conf.rxmode.max_rx_pkt_len > buf_size){
                        dev->data->scattered_rx = 1;
                        dev->rx_pkt_burst = ixgbe_recv_scattered_pkts;
                }
        }
        return 0;
}

/*
 * [VF] Initializes Transmit Unit.
 */
void
ixgbevf_dev_tx_init(struct rte_eth_dev *dev)
{
        struct ixgbe_hw     *hw;
        struct igb_tx_queue *txq;
        uint64_t bus_addr;
        uint32_t txctrl;
        uint16_t i;

        PMD_INIT_FUNC_TRACE();
        hw = IXGBE_DEV_PRIVATE_TO_HW(dev->data->dev_private);

        /* Setup the Base and Length of the Tx Descriptor Rings */
        for (i = 0; i < dev->data->nb_tx_queues; i++) {
                txq = dev->data->tx_queues[i];
                bus_addr = txq->tx_ring_phys_addr;
                IXGBE_WRITE_REG(hw, IXGBE_VFTDBAL(i),
                                (uint32_t)(bus_addr & 0x00000000ffffffffULL));
                IXGBE_WRITE_REG(hw, IXGBE_VFTDBAH(i),
                                (uint32_t)(bus_addr >> 32));
                IXGBE_WRITE_REG(hw, IXGBE_VFTDLEN(i),
                                txq->nb_tx_desc * sizeof(union ixgbe_adv_tx_desc));
                /* Setup the HW Tx Head and TX Tail descriptor pointers */
                IXGBE_WRITE_REG(hw, IXGBE_VFTDH(i), 0);
                IXGBE_WRITE_REG(hw, IXGBE_VFTDT(i), 0);

                /*
                 * Disable Tx Head Writeback RO bit, since this hoses
                 * bookkeeping if things aren't delivered in order.
                 */
                txctrl = IXGBE_READ_REG(hw,
                                IXGBE_VFDCA_TXCTRL(i));
                txctrl &= ~IXGBE_DCA_TXCTRL_TX_WB_RO_EN;
                IXGBE_WRITE_REG(hw, IXGBE_VFDCA_TXCTRL(i),
                                txctrl);
        }
}

/*
 * [VF] Start Transmit and Receive Units.
 */
void
ixgbevf_dev_rxtx_start(struct rte_eth_dev *dev)
{
        struct ixgbe_hw     *hw;
        struct igb_tx_queue *txq;
        struct igb_rx_queue *rxq;
        uint32_t txdctl;
        uint32_t rxdctl;
        uint16_t i;
        int poll_ms;

        PMD_INIT_FUNC_TRACE();
        hw = IXGBE_DEV_PRIVATE_TO_HW(dev->data->dev_private);

        for (i = 0; i < dev->data->nb_tx_queues; i++) {
                txq = dev->data->tx_queues[i];
                /* Setup Transmit Threshold Registers */
                txdctl = IXGBE_READ_REG(hw, IXGBE_VFTXDCTL(i));
                txdctl |= txq->pthresh & 0x7F;
                txdctl |= ((txq->hthresh & 0x7F) << 8);
                txdctl |= ((txq->wthresh & 0x7F) << 16);
                IXGBE_WRITE_REG(hw, IXGBE_VFTXDCTL(i), txdctl);
        }

        for (i = 0; i < dev->data->nb_tx_queues; i++) {

                txdctl = IXGBE_READ_REG(hw, IXGBE_VFTXDCTL(i));
                txdctl |= IXGBE_TXDCTL_ENABLE;
                IXGBE_WRITE_REG(hw, IXGBE_VFTXDCTL(i), txdctl);

                poll_ms = 10;
                /* Wait until TX Enable ready */
                do {
                        rte_delay_ms(1);
                        txdctl = IXGBE_READ_REG(hw, IXGBE_VFTXDCTL(i));
                } while (--poll_ms && !(txdctl & IXGBE_TXDCTL_ENABLE));
                if (!poll_ms)
                        PMD_INIT_LOG(ERR, "Could not enable "
                                         "Tx Queue %d\n", i);
        }
        for (i = 0; i < dev->data->nb_rx_queues; i++) {

                rxq = dev->data->rx_queues[i];

                rxdctl = IXGBE_READ_REG(hw, IXGBE_VFRXDCTL(i));
                rxdctl |= IXGBE_RXDCTL_ENABLE;
                IXGBE_WRITE_REG(hw, IXGBE_VFRXDCTL(i), rxdctl);

                /* Wait until RX Enable ready */
                poll_ms = 10;
                do {
                        rte_delay_ms(1);
                        rxdctl = IXGBE_READ_REG(hw, IXGBE_VFRXDCTL(i));
                } while (--poll_ms && !(rxdctl & IXGBE_RXDCTL_ENABLE));
                if (!poll_ms)
                        PMD_INIT_LOG(ERR, "Could not enable "
                                         "Rx Queue %d\n", i);
                rte_wmb();
                IXGBE_WRITE_REG(hw, IXGBE_VFRDT(i), rxq->nb_rx_desc - 1);

        }
}