Imported Upstream version 16.04
[deb_dpdk.git] / drivers / net / e1000 / em_rxtx.c
diff --git a/drivers/net/e1000/em_rxtx.c b/drivers/net/e1000/em_rxtx.c
new file mode 100644 (file)
index 0000000..441ccad
--- /dev/null
@@ -0,0 +1,1861 @@
+/*-
+ *   BSD LICENSE
+ *
+ *   Copyright(c) 2010-2015 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 <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <stdint.h>
+#include <stdarg.h>
+#include <inttypes.h>
+
+#include <rte_interrupts.h>
+#include <rte_byteorder.h>
+#include <rte_common.h>
+#include <rte_log.h>
+#include <rte_debug.h>
+#include <rte_pci.h>
+#include <rte_memory.h>
+#include <rte_memcpy.h>
+#include <rte_memzone.h>
+#include <rte_launch.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_ip.h>
+#include <rte_udp.h>
+#include <rte_tcp.h>
+#include <rte_sctp.h>
+#include <rte_string_fns.h>
+
+#include "e1000_logs.h"
+#include "base/e1000_api.h"
+#include "e1000_ethdev.h"
+#include "base/e1000_osdep.h"
+
+#define        E1000_TXD_VLAN_SHIFT    16
+
+#define E1000_RXDCTL_GRAN      0x01000000 /* RXDCTL Granularity */
+
+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, 0);
+       return m;
+}
+
+/**
+ * Structure associated with each descriptor of the RX ring of a RX queue.
+ */
+struct em_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 em_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 em_rx_queue {
+       struct rte_mempool  *mb_pool;   /**< mbuf pool to populate RX ring. */
+       volatile struct e1000_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. */
+       volatile uint32_t   *rdh_reg_addr; /**< RDH register address. */
+       struct em_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. */
+       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             pthresh;    /**< Prefetch threshold register. */
+       uint8_t             hthresh;    /**< Host threshold register. */
+       uint8_t             wthresh;    /**< Write-back threshold register. */
+       uint8_t             crc_len;    /**< 0 if CRC stripped, 4 otherwise. */
+};
+
+/**
+ * Hardware context number
+ */
+enum {
+       EM_CTX_0    = 0, /**< CTX0 */
+       EM_CTX_NUM  = 1, /**< CTX NUM */
+};
+
+/** Offload features */
+union em_vlan_macip {
+       uint32_t data;
+       struct {
+               uint16_t l3_len:9; /**< L3 (IP) Header Length. */
+               uint16_t l2_len:7; /**< L2 (MAC) Header Length. */
+               uint16_t vlan_tci;
+               /**< VLAN Tag Control Identifier (CPU order). */
+       } f;
+};
+
+/*
+ * Compare mask for vlan_macip_len.data,
+ * should be in sync with em_vlan_macip.f layout.
+ * */
+#define TX_VLAN_CMP_MASK        0xFFFF0000  /**< VLAN length - 16-bits. */
+#define TX_MAC_LEN_CMP_MASK     0x0000FE00  /**< MAC length - 7-bits. */
+#define TX_IP_LEN_CMP_MASK      0x000001FF  /**< IP  length - 9-bits. */
+/** MAC+IP  length. */
+#define TX_MACIP_LEN_CMP_MASK   (TX_MAC_LEN_CMP_MASK | TX_IP_LEN_CMP_MASK)
+
+/**
+ * Structure to check if new context need be built
+ */
+struct em_ctx_info {
+       uint64_t flags;              /**< ol_flags related to context build. */
+       uint32_t cmp_mask;           /**< compare mask */
+       union em_vlan_macip hdrlen;  /**< L2 and L3 header lenghts */
+};
+
+/**
+ * Structure associated with each TX queue.
+ */
+struct em_tx_queue {
+       volatile struct e1000_data_desc *tx_ring; /**< TX ring address */
+       uint64_t               tx_ring_phys_addr; /**< TX ring DMA address. */
+       struct em_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 register. */
+       /**< Start freeing TX buffers if there are less free descriptors than
+            this value. */
+       uint16_t               tx_free_thresh;
+       /**< 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 register. */
+       struct em_ctx_info ctx_cache;
+       /**< Hardware context history.*/
+};
+
+#if 1
+#define RTE_PMD_USE_PREFETCH
+#endif
+
+#ifdef RTE_PMD_USE_PREFETCH
+#define rte_em_prefetch(p)     rte_prefetch0(p)
+#else
+#define rte_em_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
+
+#ifndef DEFAULT_TX_FREE_THRESH
+#define DEFAULT_TX_FREE_THRESH  32
+#endif /* DEFAULT_TX_FREE_THRESH */
+
+#ifndef DEFAULT_TX_RS_THRESH
+#define DEFAULT_TX_RS_THRESH  32
+#endif /* DEFAULT_TX_RS_THRESH */
+
+
+/*********************************************************************
+ *
+ *  TX function
+ *
+ **********************************************************************/
+
+/*
+ * Populates TX context descriptor.
+ */
+static inline void
+em_set_xmit_ctx(struct em_tx_queue* txq,
+               volatile struct e1000_context_desc *ctx_txd,
+               uint64_t flags,
+               union em_vlan_macip hdrlen)
+{
+       uint32_t cmp_mask, cmd_len;
+       uint16_t ipcse, l2len;
+       struct e1000_context_desc ctx;
+
+       cmp_mask = 0;
+       cmd_len = E1000_TXD_CMD_DEXT | E1000_TXD_DTYP_C;
+
+       l2len = hdrlen.f.l2_len;
+       ipcse = (uint16_t)(l2len + hdrlen.f.l3_len);
+
+       /* setup IPCS* fields */
+       ctx.lower_setup.ip_fields.ipcss = (uint8_t)l2len;
+       ctx.lower_setup.ip_fields.ipcso = (uint8_t)(l2len +
+                       offsetof(struct ipv4_hdr, hdr_checksum));
+
+       /*
+        * When doing checksum or TCP segmentation with IPv6 headers,
+        * IPCSE field should be set t0 0.
+        */
+       if (flags & PKT_TX_IP_CKSUM) {
+               ctx.lower_setup.ip_fields.ipcse =
+                       (uint16_t)rte_cpu_to_le_16(ipcse - 1);
+               cmd_len |= E1000_TXD_CMD_IP;
+               cmp_mask |= TX_MACIP_LEN_CMP_MASK;
+       } else {
+               ctx.lower_setup.ip_fields.ipcse = 0;
+       }
+
+       /* setup TUCS* fields */
+       ctx.upper_setup.tcp_fields.tucss = (uint8_t)ipcse;
+       ctx.upper_setup.tcp_fields.tucse = 0;
+
+       switch (flags & PKT_TX_L4_MASK) {
+       case PKT_TX_UDP_CKSUM:
+               ctx.upper_setup.tcp_fields.tucso = (uint8_t)(ipcse +
+                               offsetof(struct udp_hdr, dgram_cksum));
+               cmp_mask |= TX_MACIP_LEN_CMP_MASK;
+               break;
+       case PKT_TX_TCP_CKSUM:
+               ctx.upper_setup.tcp_fields.tucso = (uint8_t)(ipcse +
+                               offsetof(struct tcp_hdr, cksum));
+               cmd_len |= E1000_TXD_CMD_TCP;
+               cmp_mask |= TX_MACIP_LEN_CMP_MASK;
+               break;
+       default:
+               ctx.upper_setup.tcp_fields.tucso = 0;
+       }
+
+       ctx.cmd_and_length = rte_cpu_to_le_32(cmd_len);
+       ctx.tcp_seg_setup.data = 0;
+
+       *ctx_txd = ctx;
+
+       txq->ctx_cache.flags = flags;
+       txq->ctx_cache.cmp_mask = cmp_mask;
+       txq->ctx_cache.hdrlen = hdrlen;
+}
+
+/*
+ * Check which hardware context can be used. Use the existing match
+ * or create a new context descriptor.
+ */
+static inline uint32_t
+what_ctx_update(struct em_tx_queue *txq, uint64_t flags,
+               union em_vlan_macip hdrlen)
+{
+       /* If match with the current context */
+       if (likely (txq->ctx_cache.flags == flags &&
+                       ((txq->ctx_cache.hdrlen.data ^ hdrlen.data) &
+                       txq->ctx_cache.cmp_mask) == 0))
+               return EM_CTX_0;
+
+       /* Mismatch */
+       return EM_CTX_NUM;
+}
+
+/* Reset transmit descriptors after they have been used */
+static inline int
+em_xmit_cleanup(struct em_tx_queue *txq)
+{
+       struct em_tx_entry *sw_ring = txq->sw_ring;
+       volatile struct e1000_data_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 = (uint16_t)(last_desc_cleaned + txq->tx_rs_thresh);
+       if (desc_to_clean_to >= nb_tx_desc)
+               desc_to_clean_to = (uint16_t)(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].upper.fields.status & E1000_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 = (uint16_t)((nb_tx_desc - last_desc_cleaned) +
+                                                       desc_to_clean_to);
+       else
+               nb_tx_to_clean = (uint16_t)(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].upper.fields.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 = (uint16_t)(txq->nb_tx_free + nb_tx_to_clean);
+
+       /* No Error */
+       return 0;
+}
+
+static inline uint32_t
+tx_desc_cksum_flags_to_upper(uint64_t ol_flags)
+{
+       static const uint32_t l4_olinfo[2] = {0, E1000_TXD_POPTS_TXSM << 8};
+       static const uint32_t l3_olinfo[2] = {0, E1000_TXD_POPTS_IXSM << 8};
+       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;
+}
+
+uint16_t
+eth_em_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
+               uint16_t nb_pkts)
+{
+       struct em_tx_queue *txq;
+       struct em_tx_entry *sw_ring;
+       struct em_tx_entry *txe, *txn;
+       volatile struct e1000_data_desc *txr;
+       volatile struct e1000_data_desc *txd;
+       struct rte_mbuf     *tx_pkt;
+       struct rte_mbuf     *m_seg;
+       uint64_t buf_dma_addr;
+       uint32_t popts_spec;
+       uint32_t cmd_type_len;
+       uint16_t slen;
+       uint64_t ol_flags;
+       uint16_t tx_id;
+       uint16_t tx_last;
+       uint16_t nb_tx;
+       uint16_t nb_used;
+       uint64_t tx_ol_req;
+       uint32_t ctx;
+       uint32_t new_ctx;
+       union em_vlan_macip hdrlen;
+
+       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_free < txq->tx_free_thresh)
+               em_xmit_cleanup(txq);
+
+       /* TX loop */
+       for (nb_tx = 0; nb_tx < nb_pkts; nb_tx++) {
+               new_ctx = 0;
+               tx_pkt = *tx_pkts++;
+
+               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;
+
+               /* If hardware offload required */
+               tx_ol_req = (ol_flags & (PKT_TX_IP_CKSUM | PKT_TX_L4_MASK));
+               if (tx_ol_req) {
+                       hdrlen.f.vlan_tci = tx_pkt->vlan_tci;
+                       hdrlen.f.l2_len = tx_pkt->l2_len;
+                       hdrlen.f.l3_len = tx_pkt->l3_len;
+                       /* If new context to be built or reuse the exist ctx. */
+                       ctx = what_ctx_update(txq, tx_ol_req, hdrlen);
+
+                       /* Only allocate context descriptor if required*/
+                       new_ctx = (ctx == EM_CTX_NUM);
+               }
+
+               /*
+                * 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 = (uint16_t)(tx_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",
+                          (unsigned) txq->port_id,
+                          (unsigned) txq->queue_id,
+                          (unsigned) tx_pkt->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
+                */
+               while (unlikely (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 (em_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:
+                *    - E1000_TXD_DTYP_DATA
+                *    - E1000_TXD_DTYP_DEXT
+                *
+                * The following bits must be set in the first Data Descriptor
+                * and are ignored in the other ones:
+                *    - E1000_TXD_POPTS_IXSM
+                *    - E1000_TXD_POPTS_TXSM
+                *
+                * The following bits must be set in the last Data Descriptor
+                * and are ignored in the other ones:
+                *    - E1000_TXD_CMD_VLE
+                *    - E1000_TXD_CMD_IFCS
+                *
+                * The following bits must only be set in the last Data
+                * Descriptor:
+                *   - E1000_TXD_CMD_EOP
+                *
+                * The following bits can be set in any Data Descriptor, but
+                * are only set in the last Data Descriptor:
+                *   - E1000_TXD_CMD_RS
+                */
+               cmd_type_len = E1000_TXD_CMD_DEXT | E1000_TXD_DTYP_D |
+                       E1000_TXD_CMD_IFCS;
+               popts_spec = 0;
+
+               /* Set VLAN Tag offload fields. */
+               if (ol_flags & PKT_TX_VLAN_PKT) {
+                       cmd_type_len |= E1000_TXD_CMD_VLE;
+                       popts_spec = tx_pkt->vlan_tci << E1000_TXD_VLAN_SHIFT;
+               }
+
+               if (tx_ol_req) {
+                       /*
+                        * Setup the TX Context Descriptor if required
+                        */
+                       if (new_ctx) {
+                               volatile struct e1000_context_desc *ctx_txd;
+
+                               ctx_txd = (volatile struct e1000_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;
+                               }
+
+                               em_set_xmit_ctx(txq, ctx_txd, tx_ol_req,
+                                       hdrlen);
+
+                               txe->last_id = tx_last;
+                               tx_id = txe->next_id;
+                               txe = txn;
+                       }
+
+                       /*
+                        * Setup the TX Data Descriptor,
+                        * This path will go through
+                        * whatever new/reuse the context descriptor
+                        */
+                       popts_spec |= tx_desc_cksum_flags_to_upper(ol_flags);
+               }
+
+               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->data_len;
+                       buf_dma_addr = rte_mbuf_data_dma_addr(m_seg);
+
+                       txd->buffer_addr = rte_cpu_to_le_64(buf_dma_addr);
+                       txd->lower.data = rte_cpu_to_le_32(cmd_type_len | slen);
+                       txd->upper.data = rte_cpu_to_le_32(popts_spec);
+
+                       txe->last_id = tx_last;
+                       tx_id = txe->next_id;
+                       txe = txn;
+                       m_seg = m_seg->next;
+               } while (m_seg != NULL);
+
+               /*
+                * The last packet data descriptor needs End Of Packet (EOP)
+                */
+               cmd_type_len |= E1000_TXD_CMD_EOP;
+               txq->nb_tx_used = (uint16_t)(txq->nb_tx_used + nb_used);
+               txq->nb_tx_free = (uint16_t)(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 |= E1000_TXD_CMD_RS;
+
+                       /* Update txq RS bit counters */
+                       txq->nb_tx_used = 0;
+               }
+               txd->lower.data |= 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);
+       E1000_PCI_REG_WRITE(txq->tdt_reg_addr, tx_id);
+       txq->tx_tail = tx_id;
+
+       return nb_tx;
+}
+
+/*********************************************************************
+ *
+ *  RX functions
+ *
+ **********************************************************************/
+
+static inline uint64_t
+rx_desc_status_to_pkt_flags(uint32_t rx_status)
+{
+       uint64_t pkt_flags;
+
+       /* Check if VLAN present */
+       pkt_flags = ((rx_status & E1000_RXD_STAT_VP) ?  PKT_RX_VLAN_PKT : 0);
+
+       return pkt_flags;
+}
+
+static inline uint64_t
+rx_desc_error_to_pkt_flags(uint32_t rx_error)
+{
+       uint64_t pkt_flags = 0;
+
+       if (rx_error & E1000_RXD_ERR_IPE)
+               pkt_flags |= PKT_RX_IP_CKSUM_BAD;
+       if (rx_error & E1000_RXD_ERR_TCPE)
+               pkt_flags |= PKT_RX_L4_CKSUM_BAD;
+       return pkt_flags;
+}
+
+uint16_t
+eth_em_recv_pkts(void *rx_queue, struct rte_mbuf **rx_pkts,
+               uint16_t nb_pkts)
+{
+       volatile struct e1000_rx_desc *rx_ring;
+       volatile struct e1000_rx_desc *rxdp;
+       struct em_rx_queue *rxq;
+       struct em_rx_entry *sw_ring;
+       struct em_rx_entry *rxe;
+       struct rte_mbuf *rxm;
+       struct rte_mbuf *nmb;
+       struct e1000_rx_desc rxd;
+       uint64_t dma_addr;
+       uint16_t pkt_len;
+       uint16_t rx_id;
+       uint16_t nb_rx;
+       uint16_t nb_hold;
+       uint8_t status;
+
+       rxq = rx_queue;
+
+       nb_rx = 0;
+       nb_hold = 0;
+       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];
+               status = rxdp->status;
+               if (! (status & E1000_RXD_STAT_DD))
+                       break;
+               rxd = *rxdp;
+
+               /*
+                * End of packet.
+                *
+                * If the E1000_RXD_STAT_EOP flag is not set, the RX packet is
+                * likely to be invalid and to be dropped by the various
+                * validation checks performed by the network stack.
+                *
+                * Allocate a new mbuf to replenish the RX ring descriptor.
+                * If the allocation fails:
+                *    - arrange for that RX descriptor to be the first one
+                *      being parsed the next time the receive function is
+                *      invoked [on the same queue].
+                *
+                *    - Stop parsing the RX ring and return immediately.
+                *
+                * This policy do not drop the packet received in the RX
+                * descriptor for which the allocation of a new mbuf failed.
+                * Thus, it allows that packet to be later retrieved if
+                * mbuf have been freed in the mean time.
+                * As a side effect, holding RX descriptors instead of
+                * systematically giving them back to the NIC may lead to
+                * RX ring exhaustion situations.
+                * However, the NIC can gracefully prevent such situations
+                * to happen by sending specific "back-pressure" flow control
+                * frames to its peer(s).
+                */
+               PMD_RX_LOG(DEBUG, "port_id=%u queue_id=%u rx_id=%u "
+                          "status=0x%x pkt_len=%u",
+                          (unsigned) rxq->port_id, (unsigned) rxq->queue_id,
+                          (unsigned) rx_id, (unsigned) status,
+                          (unsigned) rte_le_to_cpu_16(rxd.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",
+                                  (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_em_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_em_prefetch(&rx_ring[rx_id]);
+                       rte_em_prefetch(&sw_ring[rx_id]);
+               }
+
+               /* Rearm RXD: attach new mbuf and reset status to zero. */
+
+               rxm = rxe->mbuf;
+               rxe->mbuf = nmb;
+               dma_addr =
+                       rte_cpu_to_le_64(rte_mbuf_data_dma_addr_default(nmb));
+               rxdp->buffer_addr = dma_addr;
+               rxdp->status = 0;
+
+               /*
+                * 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.length) -
+                               rxq->crc_len);
+               rxm->data_off = RTE_PKTMBUF_HEADROOM;
+               rte_packet_prefetch((char *)rxm->buf_addr + rxm->data_off);
+               rxm->nb_segs = 1;
+               rxm->next = NULL;
+               rxm->pkt_len = pkt_len;
+               rxm->data_len = pkt_len;
+               rxm->port = rxq->port_id;
+
+               rxm->ol_flags = rx_desc_status_to_pkt_flags(status);
+               rxm->ol_flags = rxm->ol_flags |
+                               rx_desc_error_to_pkt_flags(rxd.errors);
+
+               /* Only valid if PKT_RX_VLAN_PKT set in pkt_flags */
+               rxm->vlan_tci = rte_le_to_cpu_16(rxd.special);
+
+               /*
+                * 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",
+                          (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));
+               E1000_PCI_REG_WRITE(rxq->rdt_reg_addr, rx_id);
+               nb_hold = 0;
+       }
+       rxq->nb_rx_hold = nb_hold;
+       return nb_rx;
+}
+
+uint16_t
+eth_em_recv_scattered_pkts(void *rx_queue, struct rte_mbuf **rx_pkts,
+                        uint16_t nb_pkts)
+{
+       struct em_rx_queue *rxq;
+       volatile struct e1000_rx_desc *rx_ring;
+       volatile struct e1000_rx_desc *rxdp;
+       struct em_rx_entry *sw_ring;
+       struct em_rx_entry *rxe;
+       struct rte_mbuf *first_seg;
+       struct rte_mbuf *last_seg;
+       struct rte_mbuf *rxm;
+       struct rte_mbuf *nmb;
+       struct e1000_rx_desc rxd;
+       uint64_t dma; /* Physical address of mbuf data buffer */
+       uint16_t rx_id;
+       uint16_t nb_rx;
+       uint16_t nb_hold;
+       uint16_t data_len;
+       uint8_t status;
+
+       rxq = rx_queue;
+
+       nb_rx = 0;
+       nb_hold = 0;
+       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];
+               status = rxdp->status;
+               if (! (status & E1000_RXD_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, "port_id=%u queue_id=%u rx_id=%u "
+                          "status=0x%x data_len=%u",
+                          (unsigned) rxq->port_id, (unsigned) rxq->queue_id,
+                          (unsigned) rx_id, (unsigned) status,
+                          (unsigned) rte_le_to_cpu_16(rxd.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", (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_em_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_em_prefetch(&rx_ring[rx_id]);
+                       rte_em_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->buffer_addr = dma;
+               rxdp->status = 0;
+
+               /*
+                * Set data length & data buffer address of mbuf.
+                */
+               data_len = rte_le_to_cpu_16(rxd.length);
+               rxm->data_len = data_len;
+               rxm->data_off = 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_len = data_len;
+                       first_seg->nb_segs = 1;
+               } else {
+                       first_seg->pkt_len += data_len;
+                       first_seg->nb_segs++;
+                       last_seg->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 (! (status & E1000_RXD_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->next = NULL;
+               if (unlikely(rxq->crc_len > 0)) {
+                       first_seg->pkt_len -= ETHER_CRC_LEN;
+                       if (data_len <= ETHER_CRC_LEN) {
+                               rte_pktmbuf_free_seg(rxm);
+                               first_seg->nb_segs--;
+                               last_seg->data_len = (uint16_t)
+                                       (last_seg->data_len -
+                                        (ETHER_CRC_LEN - data_len));
+                               last_seg->next = NULL;
+                       } else
+                               rxm->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:
+                *      - IP checksum flag,
+                *      - error flags.
+                */
+               first_seg->port = rxq->port_id;
+
+               first_seg->ol_flags = rx_desc_status_to_pkt_flags(status);
+               first_seg->ol_flags = first_seg->ol_flags |
+                                       rx_desc_error_to_pkt_flags(rxd.errors);
+
+               /* Only valid if PKT_RX_VLAN_PKT set in pkt_flags */
+               rxm->vlan_tci = rte_le_to_cpu_16(rxd.special);
+
+               /* Prefetch data of first segment, if configured to do so. */
+               rte_packet_prefetch((char *)first_seg->buf_addr +
+                       first_seg->data_off);
+
+               /*
+                * 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",
+                          (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));
+               E1000_PCI_REG_WRITE(rxq->rdt_reg_addr, rx_id);
+               nb_hold = 0;
+       }
+       rxq->nb_rx_hold = nb_hold;
+       return nb_rx;
+}
+
+#define        EM_MAX_BUF_SIZE     16384
+#define EM_RCTL_FLXBUF_STEP 1024
+
+static void
+em_tx_queue_release_mbufs(struct em_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
+em_tx_queue_release(struct em_tx_queue *txq)
+{
+       if (txq != NULL) {
+               em_tx_queue_release_mbufs(txq);
+               rte_free(txq->sw_ring);
+               rte_free(txq);
+       }
+}
+
+void
+eth_em_tx_queue_release(void *txq)
+{
+       em_tx_queue_release(txq);
+}
+
+/* (Re)set dynamic em_tx_queue fields to defaults */
+static void
+em_reset_tx_queue(struct em_tx_queue *txq)
+{
+       uint16_t i, nb_desc, prev;
+       static const struct e1000_data_desc txd_init = {
+               .upper.fields = {.status = E1000_TXD_STAT_DD},
+       };
+
+       nb_desc = txq->nb_tx_desc;
+
+       /* Initialize ring entries */
+
+       prev = (uint16_t) (nb_desc - 1);
+
+       for (i = 0; i < nb_desc; i++) {
+               txq->tx_ring[i] = txd_init;
+               txq->sw_ring[i].mbuf = NULL;
+               txq->sw_ring[i].last_id = i;
+               txq->sw_ring[prev].next_id = i;
+               prev = i;
+       }
+
+       /*
+        * Always allow 1 descriptor to be un-allocated to avoid
+        * a H/W race condition
+        */
+       txq->nb_tx_free = (uint16_t)(nb_desc - 1);
+       txq->last_desc_cleaned = (uint16_t)(nb_desc - 1);
+       txq->nb_tx_used = 0;
+       txq->tx_tail = 0;
+
+       memset((void*)&txq->ctx_cache, 0, sizeof (txq->ctx_cache));
+}
+
+int
+eth_em_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 em_tx_queue *txq;
+       struct e1000_hw     *hw;
+       uint32_t tsize;
+       uint16_t tx_rs_thresh, tx_free_thresh;
+
+       hw = E1000_DEV_PRIVATE_TO_HW(dev->data->dev_private);
+
+       /*
+        * Validate number of transmit descriptors.
+        * It must not exceed hardware maximum, and must be multiple
+        * of E1000_ALIGN.
+        */
+       if (nb_desc % EM_TXD_ALIGN != 0 ||
+                       (nb_desc > E1000_MAX_RING_DESC) ||
+                       (nb_desc < E1000_MIN_RING_DESC)) {
+               return -(EINVAL);
+       }
+
+       tx_free_thresh = tx_conf->tx_free_thresh;
+       if (tx_free_thresh == 0)
+               tx_free_thresh = (uint16_t)RTE_MIN(nb_desc / 4,
+                                       DEFAULT_TX_FREE_THRESH);
+
+       tx_rs_thresh = tx_conf->tx_rs_thresh;
+       if (tx_rs_thresh == 0)
+               tx_rs_thresh = (uint16_t)RTE_MIN(tx_free_thresh,
+                                       DEFAULT_TX_RS_THRESH);
+
+       if (tx_free_thresh >= (nb_desc - 3)) {
+               PMD_INIT_LOG(ERR, "tx_free_thresh must be less than the "
+                            "number of TX descriptors minus 3. "
+                            "(tx_free_thresh=%u port=%d queue=%d)",
+                            (unsigned int)tx_free_thresh,
+                            (int)dev->data->port_id, (int)queue_idx);
+               return -(EINVAL);
+       }
+       if (tx_rs_thresh > tx_free_thresh) {
+               PMD_INIT_LOG(ERR, "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)",
+                            (unsigned int)tx_free_thresh,
+                            (unsigned int)tx_rs_thresh,
+                            (int)dev->data->port_id,
+                            (int)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_conf->tx_thresh.wthresh != 0 && tx_rs_thresh != 1) {
+               PMD_INIT_LOG(ERR, "TX WTHRESH must be set to 0 if "
+                            "tx_rs_thresh is greater than 1. (tx_rs_thresh=%u "
+                            "port=%d queue=%d)", (unsigned int)tx_rs_thresh,
+                            (int)dev->data->port_id, (int)queue_idx);
+               return -(EINVAL);
+       }
+
+       /* Free memory prior to re-allocation if needed... */
+       if (dev->data->tx_queues[queue_idx] != NULL) {
+               em_tx_queue_release(dev->data->tx_queues[queue_idx]);
+               dev->data->tx_queues[queue_idx] = NULL;
+       }
+
+       /*
+        * 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.
+        */
+       tsize = sizeof(txq->tx_ring[0]) * E1000_MAX_RING_DESC;
+       tz = rte_eth_dma_zone_reserve(dev, "tx_ring", queue_idx, tsize,
+                                     RTE_CACHE_LINE_SIZE, socket_id);
+       if (tz == NULL)
+               return -ENOMEM;
+
+       /* Allocate the tx queue data structure. */
+       if ((txq = rte_zmalloc("ethdev TX queue", sizeof(*txq),
+                       RTE_CACHE_LINE_SIZE)) == NULL)
+               return -ENOMEM;
+
+       /* Allocate software ring */
+       if ((txq->sw_ring = rte_zmalloc("txq->sw_ring",
+                       sizeof(txq->sw_ring[0]) * nb_desc,
+                       RTE_CACHE_LINE_SIZE)) == NULL) {
+               em_tx_queue_release(txq);
+               return -ENOMEM;
+       }
+
+       txq->nb_tx_desc = nb_desc;
+       txq->tx_free_thresh = tx_free_thresh;
+       txq->tx_rs_thresh = tx_rs_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;
+
+       txq->tdt_reg_addr = E1000_PCI_REG_ADDR(hw, E1000_TDT(queue_idx));
+       txq->tx_ring_phys_addr = rte_mem_phy2mch(tz->memseg_id, tz->phys_addr);
+       txq->tx_ring = (struct e1000_data_desc *) tz->addr;
+
+       PMD_INIT_LOG(DEBUG, "sw_ring=%p hw_ring=%p dma_addr=0x%"PRIx64,
+                    txq->sw_ring, txq->tx_ring, txq->tx_ring_phys_addr);
+
+       em_reset_tx_queue(txq);
+
+       dev->data->tx_queues[queue_idx] = txq;
+       return 0;
+}
+
+static void
+em_rx_queue_release_mbufs(struct em_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;
+                       }
+               }
+       }
+}
+
+static void
+em_rx_queue_release(struct em_rx_queue *rxq)
+{
+       if (rxq != NULL) {
+               em_rx_queue_release_mbufs(rxq);
+               rte_free(rxq->sw_ring);
+               rte_free(rxq);
+       }
+}
+
+void
+eth_em_rx_queue_release(void *rxq)
+{
+       em_rx_queue_release(rxq);
+}
+
+/* Reset dynamic em_rx_queue fields back to defaults */
+static void
+em_reset_rx_queue(struct em_rx_queue *rxq)
+{
+       rxq->rx_tail = 0;
+       rxq->nb_rx_hold = 0;
+       rxq->pkt_first_seg = NULL;
+       rxq->pkt_last_seg = NULL;
+}
+
+int
+eth_em_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 em_rx_queue *rxq;
+       struct e1000_hw     *hw;
+       uint32_t rsize;
+
+       hw = E1000_DEV_PRIVATE_TO_HW(dev->data->dev_private);
+
+       /*
+        * Validate number of receive descriptors.
+        * It must not exceed hardware maximum, and must be multiple
+        * of E1000_ALIGN.
+        */
+       if (nb_desc % EM_RXD_ALIGN != 0 ||
+                       (nb_desc > E1000_MAX_RING_DESC) ||
+                       (nb_desc < E1000_MIN_RING_DESC)) {
+               return -EINVAL;
+       }
+
+       /*
+        * EM devices don't support drop_en functionality
+        */
+       if (rx_conf->rx_drop_en) {
+               PMD_INIT_LOG(ERR, "drop_en functionality not supported by "
+                            "device");
+               return -EINVAL;
+       }
+
+       /* Free memory prior to re-allocation if needed. */
+       if (dev->data->rx_queues[queue_idx] != NULL) {
+               em_rx_queue_release(dev->data->rx_queues[queue_idx]);
+               dev->data->rx_queues[queue_idx] = NULL;
+       }
+
+       /* Allocate RX ring for max possible mumber of hardware descriptors. */
+       rsize = sizeof(rxq->rx_ring[0]) * E1000_MAX_RING_DESC;
+       rz = rte_eth_dma_zone_reserve(dev, "rx_ring", queue_idx, rsize,
+                                     RTE_CACHE_LINE_SIZE, socket_id);
+       if (rz == NULL)
+               return -ENOMEM;
+
+       /* Allocate the RX queue data structure. */
+       if ((rxq = rte_zmalloc("ethdev RX queue", sizeof(*rxq),
+                       RTE_CACHE_LINE_SIZE)) == NULL)
+               return -ENOMEM;
+
+       /* Allocate software ring. */
+       if ((rxq->sw_ring = rte_zmalloc("rxq->sw_ring",
+                       sizeof (rxq->sw_ring[0]) * nb_desc,
+                       RTE_CACHE_LINE_SIZE)) == NULL) {
+               em_rx_queue_release(rxq);
+               return -ENOMEM;
+       }
+
+       rxq->mb_pool = mp;
+       rxq->nb_rx_desc = nb_desc;
+       rxq->pthresh = rx_conf->rx_thresh.pthresh;
+       rxq->hthresh = rx_conf->rx_thresh.hthresh;
+       rxq->wthresh = rx_conf->rx_thresh.wthresh;
+       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);
+
+       rxq->rdt_reg_addr = E1000_PCI_REG_ADDR(hw, E1000_RDT(queue_idx));
+       rxq->rdh_reg_addr = E1000_PCI_REG_ADDR(hw, E1000_RDH(queue_idx));
+       rxq->rx_ring_phys_addr = rte_mem_phy2mch(rz->memseg_id, rz->phys_addr);
+       rxq->rx_ring = (struct e1000_rx_desc *) rz->addr;
+
+       PMD_INIT_LOG(DEBUG, "sw_ring=%p hw_ring=%p dma_addr=0x%"PRIx64,
+                    rxq->sw_ring, rxq->rx_ring, rxq->rx_ring_phys_addr);
+
+       dev->data->rx_queues[queue_idx] = rxq;
+       em_reset_rx_queue(rxq);
+
+       return 0;
+}
+
+uint32_t
+eth_em_rx_queue_count(struct rte_eth_dev *dev, uint16_t rx_queue_id)
+{
+#define EM_RXQ_SCAN_INTERVAL 4
+       volatile struct e1000_rx_desc *rxdp;
+       struct em_rx_queue *rxq;
+       uint32_t desc = 0;
+
+       if (rx_queue_id >= dev->data->nb_rx_queues) {
+               PMD_RX_LOG(DEBUG, "Invalid RX queue_id=%d", rx_queue_id);
+               return 0;
+       }
+
+       rxq = dev->data->rx_queues[rx_queue_id];
+       rxdp = &(rxq->rx_ring[rxq->rx_tail]);
+
+       while ((desc < rxq->nb_rx_desc) &&
+               (rxdp->status & E1000_RXD_STAT_DD)) {
+               desc += EM_RXQ_SCAN_INTERVAL;
+               rxdp += EM_RXQ_SCAN_INTERVAL;
+               if (rxq->rx_tail + desc >= rxq->nb_rx_desc)
+                       rxdp = &(rxq->rx_ring[rxq->rx_tail +
+                               desc - rxq->nb_rx_desc]);
+       }
+
+       return desc;
+}
+
+int
+eth_em_rx_descriptor_done(void *rx_queue, uint16_t offset)
+{
+       volatile struct e1000_rx_desc *rxdp;
+       struct em_rx_queue *rxq = rx_queue;
+       uint32_t desc;
+
+       if (unlikely(offset >= rxq->nb_rx_desc))
+               return 0;
+       desc = rxq->rx_tail + offset;
+       if (desc >= rxq->nb_rx_desc)
+               desc -= rxq->nb_rx_desc;
+
+       rxdp = &rxq->rx_ring[desc];
+       return !!(rxdp->status & E1000_RXD_STAT_DD);
+}
+
+void
+em_dev_clear_queues(struct rte_eth_dev *dev)
+{
+       uint16_t i;
+       struct em_tx_queue *txq;
+       struct em_rx_queue *rxq;
+
+       for (i = 0; i < dev->data->nb_tx_queues; i++) {
+               txq = dev->data->tx_queues[i];
+               if (txq != NULL) {
+                       em_tx_queue_release_mbufs(txq);
+                       em_reset_tx_queue(txq);
+               }
+       }
+
+       for (i = 0; i < dev->data->nb_rx_queues; i++) {
+               rxq = dev->data->rx_queues[i];
+               if (rxq != NULL) {
+                       em_rx_queue_release_mbufs(rxq);
+                       em_reset_rx_queue(rxq);
+               }
+       }
+}
+
+void
+em_dev_free_queues(struct rte_eth_dev *dev)
+{
+       uint16_t i;
+
+       for (i = 0; i < dev->data->nb_rx_queues; i++) {
+               eth_em_rx_queue_release(dev->data->rx_queues[i]);
+               dev->data->rx_queues[i] = NULL;
+       }
+       dev->data->nb_rx_queues = 0;
+
+       for (i = 0; i < dev->data->nb_tx_queues; i++) {
+               eth_em_tx_queue_release(dev->data->tx_queues[i]);
+               dev->data->tx_queues[i] = NULL;
+       }
+       dev->data->nb_tx_queues = 0;
+}
+
+/*
+ * Takes as input/output parameter RX buffer size.
+ * Returns (BSIZE | BSEX | FLXBUF) fields of RCTL register.
+ */
+static uint32_t
+em_rctl_bsize(__rte_unused enum e1000_mac_type hwtyp, uint32_t *bufsz)
+{
+       /*
+        * For BSIZE & BSEX all configurable sizes are:
+        * 16384: rctl |= (E1000_RCTL_SZ_16384 | E1000_RCTL_BSEX);
+        *  8192: rctl |= (E1000_RCTL_SZ_8192  | E1000_RCTL_BSEX);
+        *  4096: rctl |= (E1000_RCTL_SZ_4096  | E1000_RCTL_BSEX);
+        *  2048: rctl |= E1000_RCTL_SZ_2048;
+        *  1024: rctl |= E1000_RCTL_SZ_1024;
+        *   512: rctl |= E1000_RCTL_SZ_512;
+        *   256: rctl |= E1000_RCTL_SZ_256;
+        */
+       static const struct {
+               uint32_t bufsz;
+               uint32_t rctl;
+       } bufsz_to_rctl[] = {
+               {16384, (E1000_RCTL_SZ_16384 | E1000_RCTL_BSEX)},
+               {8192,  (E1000_RCTL_SZ_8192  | E1000_RCTL_BSEX)},
+               {4096,  (E1000_RCTL_SZ_4096  | E1000_RCTL_BSEX)},
+               {2048,  E1000_RCTL_SZ_2048},
+               {1024,  E1000_RCTL_SZ_1024},
+               {512,   E1000_RCTL_SZ_512},
+               {256,   E1000_RCTL_SZ_256},
+       };
+
+       int i;
+       uint32_t rctl_bsize;
+
+       rctl_bsize = *bufsz;
+
+       /*
+        * Starting from 82571 it is possible to specify RX buffer size
+        * by RCTL.FLXBUF. When this field is different from zero, the
+        * RX buffer size = RCTL.FLXBUF * 1K
+        * (e.g. t is possible to specify RX buffer size  1,2,...,15KB).
+        * It is working ok on real HW, but by some reason doesn't work
+        * on VMware emulated 82574L.
+        * So for now, always use BSIZE/BSEX to setup RX buffer size.
+        * If you don't plan to use it on VMware emulated 82574L and
+        * would like to specify RX buffer size in 1K granularity,
+        * uncomment the following lines:
+        * ***************************************************************
+        * if (hwtyp >= e1000_82571 && hwtyp <= e1000_82574 &&
+        *              rctl_bsize >= EM_RCTL_FLXBUF_STEP) {
+        *      rctl_bsize /= EM_RCTL_FLXBUF_STEP;
+        *      *bufsz = rctl_bsize;
+        *      return (rctl_bsize << E1000_RCTL_FLXBUF_SHIFT &
+        *              E1000_RCTL_FLXBUF_MASK);
+        * }
+        * ***************************************************************
+        */
+
+       for (i = 0; i != sizeof(bufsz_to_rctl) / sizeof(bufsz_to_rctl[0]);
+                       i++) {
+               if (rctl_bsize >= bufsz_to_rctl[i].bufsz) {
+                       *bufsz = bufsz_to_rctl[i].bufsz;
+                       return bufsz_to_rctl[i].rctl;
+               }
+       }
+
+       /* Should never happen. */
+       return -EINVAL;
+}
+
+static int
+em_alloc_rx_queue_mbufs(struct em_rx_queue *rxq)
+{
+       struct em_rx_entry *rxe = rxq->sw_ring;
+       uint64_t dma_addr;
+       unsigned i;
+       static const struct e1000_rx_desc rxd_init = {
+               .buffer_addr = 0,
+       };
+
+       /* Initialize software ring entries */
+       for (i = 0; i < rxq->nb_rx_desc; i++) {
+               volatile struct e1000_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=%hu", rxq->queue_id);
+                       return -ENOMEM;
+               }
+
+               dma_addr =
+                       rte_cpu_to_le_64(rte_mbuf_data_dma_addr_default(mbuf));
+
+               /* Clear HW ring memory */
+               rxq->rx_ring[i] = rxd_init;
+
+               rxd = &rxq->rx_ring[i];
+               rxd->buffer_addr = dma_addr;
+               rxe[i].mbuf = mbuf;
+       }
+
+       return 0;
+}
+
+/*********************************************************************
+ *
+ *  Enable receive unit.
+ *
+ **********************************************************************/
+int
+eth_em_rx_init(struct rte_eth_dev *dev)
+{
+       struct e1000_hw *hw;
+       struct em_rx_queue *rxq;
+       uint32_t rctl;
+       uint32_t rfctl;
+       uint32_t rxcsum;
+       uint32_t rctl_bsize;
+       uint16_t i;
+       int ret;
+
+       hw = E1000_DEV_PRIVATE_TO_HW(dev->data->dev_private);
+
+       /*
+        * Make sure receives are disabled while setting
+        * up the descriptor ring.
+        */
+       rctl = E1000_READ_REG(hw, E1000_RCTL);
+       E1000_WRITE_REG(hw, E1000_RCTL, rctl & ~E1000_RCTL_EN);
+
+       rfctl = E1000_READ_REG(hw, E1000_RFCTL);
+
+       /* Disable extended descriptor type. */
+       rfctl &= ~E1000_RFCTL_EXTEN;
+       /* Disable accelerated acknowledge */
+       if (hw->mac.type == e1000_82574)
+               rfctl |= E1000_RFCTL_ACK_DIS;
+
+       E1000_WRITE_REG(hw, E1000_RFCTL, rfctl);
+
+       /*
+        * XXX TEMPORARY WORKAROUND: on some systems with 82573
+        * long latencies are observed, like Lenovo X60. This
+        * change eliminates the problem, but since having positive
+        * values in RDTR is a known source of problems on other
+        * platforms another solution is being sought.
+        */
+       if (hw->mac.type == e1000_82573)
+               E1000_WRITE_REG(hw, E1000_RDTR, 0x20);
+
+       dev->rx_pkt_burst = (eth_rx_burst_t)eth_em_recv_pkts;
+
+       /* Determine RX bufsize. */
+       rctl_bsize = EM_MAX_BUF_SIZE;
+       for (i = 0; i < dev->data->nb_rx_queues; i++) {
+               uint32_t buf_size;
+
+               rxq = dev->data->rx_queues[i];
+               buf_size = rte_pktmbuf_data_room_size(rxq->mb_pool) -
+                       RTE_PKTMBUF_HEADROOM;
+               rctl_bsize = RTE_MIN(rctl_bsize, buf_size);
+       }
+
+       rctl |= em_rctl_bsize(hw->mac.type, &rctl_bsize);
+
+       /* Configure and enable each RX queue. */
+       for (i = 0; i < dev->data->nb_rx_queues; i++) {
+               uint64_t bus_addr;
+               uint32_t rxdctl;
+
+               rxq = dev->data->rx_queues[i];
+
+               /* Allocate buffers for descriptor rings and setup queue */
+               ret = em_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);
+
+               bus_addr = rxq->rx_ring_phys_addr;
+               E1000_WRITE_REG(hw, E1000_RDLEN(i),
+                               rxq->nb_rx_desc *
+                               sizeof(*rxq->rx_ring));
+               E1000_WRITE_REG(hw, E1000_RDBAH(i),
+                               (uint32_t)(bus_addr >> 32));
+               E1000_WRITE_REG(hw, E1000_RDBAL(i), (uint32_t)bus_addr);
+
+               E1000_WRITE_REG(hw, E1000_RDH(i), 0);
+               E1000_WRITE_REG(hw, E1000_RDT(i), rxq->nb_rx_desc - 1);
+
+               rxdctl = E1000_READ_REG(hw, E1000_RXDCTL(0));
+               rxdctl &= 0xFE000000;
+               rxdctl |= rxq->pthresh & 0x3F;
+               rxdctl |= (rxq->hthresh & 0x3F) << 8;
+               rxdctl |= (rxq->wthresh & 0x3F) << 16;
+               rxdctl |= E1000_RXDCTL_GRAN;
+               E1000_WRITE_REG(hw, E1000_RXDCTL(i), rxdctl);
+
+               /*
+                * Due to EM devices not having any sort of hardware
+                * limit for packet length, jumbo frame of any size
+                * can be accepted, thus we have to enable scattered
+                * rx if jumbo frames are enabled (or if buffer size
+                * is too small to accommodate non-jumbo packets)
+                * to avoid splitting packets that don't fit into
+                * one buffer.
+                */
+               if (dev->data->dev_conf.rxmode.jumbo_frame ||
+                               rctl_bsize < ETHER_MAX_LEN) {
+                       if (!dev->data->scattered_rx)
+                               PMD_INIT_LOG(DEBUG, "forcing scatter mode");
+                       dev->rx_pkt_burst =
+                               (eth_rx_burst_t)eth_em_recv_scattered_pkts;
+                       dev->data->scattered_rx = 1;
+               }
+       }
+
+       if (dev->data->dev_conf.rxmode.enable_scatter) {
+               if (!dev->data->scattered_rx)
+                       PMD_INIT_LOG(DEBUG, "forcing scatter mode");
+               dev->rx_pkt_burst = eth_em_recv_scattered_pkts;
+               dev->data->scattered_rx = 1;
+       }
+
+       /*
+        * Setup the Checksum Register.
+        * Receive Full-Packet Checksum Offload is mutually exclusive with RSS.
+        */
+       rxcsum = E1000_READ_REG(hw, E1000_RXCSUM);
+
+       if (dev->data->dev_conf.rxmode.hw_ip_checksum)
+               rxcsum |= E1000_RXCSUM_IPOFL;
+       else
+               rxcsum &= ~E1000_RXCSUM_IPOFL;
+       E1000_WRITE_REG(hw, E1000_RXCSUM, rxcsum);
+
+       /* No MRQ or RSS support for now */
+
+       /* Set early receive threshold on appropriate hw */
+       if ((hw->mac.type == e1000_ich9lan ||
+                       hw->mac.type == e1000_pch2lan ||
+                       hw->mac.type == e1000_ich10lan) &&
+                       dev->data->dev_conf.rxmode.jumbo_frame == 1) {
+               u32 rxdctl = E1000_READ_REG(hw, E1000_RXDCTL(0));
+               E1000_WRITE_REG(hw, E1000_RXDCTL(0), rxdctl | 3);
+               E1000_WRITE_REG(hw, E1000_ERT, 0x100 | (1 << 13));
+       }
+
+       if (hw->mac.type == e1000_pch2lan) {
+               if (dev->data->dev_conf.rxmode.jumbo_frame == 1)
+                       e1000_lv_jumbo_workaround_ich8lan(hw, TRUE);
+               else
+                       e1000_lv_jumbo_workaround_ich8lan(hw, FALSE);
+       }
+
+       /* Setup the Receive Control Register. */
+       if (dev->data->dev_conf.rxmode.hw_strip_crc)
+               rctl |= E1000_RCTL_SECRC; /* Strip Ethernet CRC. */
+       else
+               rctl &= ~E1000_RCTL_SECRC; /* Do not Strip Ethernet CRC. */
+
+       rctl &= ~(3 << E1000_RCTL_MO_SHIFT);
+       rctl |= E1000_RCTL_EN | E1000_RCTL_BAM | E1000_RCTL_LBM_NO |
+               E1000_RCTL_RDMTS_HALF |
+               (hw->mac.mc_filter_type << E1000_RCTL_MO_SHIFT);
+
+       /* Make sure VLAN Filters are off. */
+       rctl &= ~E1000_RCTL_VFE;
+       /* Don't store bad packets. */
+       rctl &= ~E1000_RCTL_SBP;
+       /* Legacy descriptor type. */
+       rctl &= ~E1000_RCTL_DTYP_MASK;
+
+       /*
+        * Configure support of jumbo frames, if any.
+        */
+       if (dev->data->dev_conf.rxmode.jumbo_frame == 1)
+               rctl |= E1000_RCTL_LPE;
+       else
+               rctl &= ~E1000_RCTL_LPE;
+
+       /* Enable Receives. */
+       E1000_WRITE_REG(hw, E1000_RCTL, rctl);
+
+       return 0;
+}
+
+/*********************************************************************
+ *
+ *  Enable transmit unit.
+ *
+ **********************************************************************/
+void
+eth_em_tx_init(struct rte_eth_dev *dev)
+{
+       struct e1000_hw     *hw;
+       struct em_tx_queue *txq;
+       uint32_t tctl;
+       uint32_t txdctl;
+       uint16_t i;
+
+       hw = E1000_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++) {
+               uint64_t bus_addr;
+
+               txq = dev->data->tx_queues[i];
+               bus_addr = txq->tx_ring_phys_addr;
+               E1000_WRITE_REG(hw, E1000_TDLEN(i),
+                               txq->nb_tx_desc *
+                               sizeof(*txq->tx_ring));
+               E1000_WRITE_REG(hw, E1000_TDBAH(i),
+                               (uint32_t)(bus_addr >> 32));
+               E1000_WRITE_REG(hw, E1000_TDBAL(i), (uint32_t)bus_addr);
+
+               /* Setup the HW Tx Head and Tail descriptor pointers. */
+               E1000_WRITE_REG(hw, E1000_TDT(i), 0);
+               E1000_WRITE_REG(hw, E1000_TDH(i), 0);
+
+               /* Setup Transmit threshold registers. */
+               txdctl = E1000_READ_REG(hw, E1000_TXDCTL(i));
+               /*
+                * bit 22 is reserved, on some models should always be 0,
+                * on others  - always 1.
+                */
+               txdctl &= E1000_TXDCTL_COUNT_DESC;
+               txdctl |= txq->pthresh & 0x3F;
+               txdctl |= (txq->hthresh & 0x3F) << 8;
+               txdctl |= (txq->wthresh & 0x3F) << 16;
+               txdctl |= E1000_TXDCTL_GRAN;
+               E1000_WRITE_REG(hw, E1000_TXDCTL(i), txdctl);
+       }
+
+       /* Program the Transmit Control Register. */
+       tctl = E1000_READ_REG(hw, E1000_TCTL);
+       tctl &= ~E1000_TCTL_CT;
+       tctl |= (E1000_TCTL_PSP | E1000_TCTL_RTLC | E1000_TCTL_EN |
+                (E1000_COLLISION_THRESHOLD << E1000_CT_SHIFT));
+
+       /* This write will effectively turn on the transmit unit. */
+       E1000_WRITE_REG(hw, E1000_TCTL, tctl);
+}
+
+void
+em_rxq_info_get(struct rte_eth_dev *dev, uint16_t queue_id,
+       struct rte_eth_rxq_info *qinfo)
+{
+       struct em_rx_queue *rxq;
+
+       rxq = dev->data->rx_queues[queue_id];
+
+       qinfo->mp = rxq->mb_pool;
+       qinfo->scattered_rx = dev->data->scattered_rx;
+       qinfo->nb_desc = rxq->nb_rx_desc;
+       qinfo->conf.rx_free_thresh = rxq->rx_free_thresh;
+}
+
+void
+em_txq_info_get(struct rte_eth_dev *dev, uint16_t queue_id,
+       struct rte_eth_txq_info *qinfo)
+{
+       struct em_tx_queue *txq;
+
+       txq = dev->data->tx_queues[queue_id];
+
+       qinfo->nb_desc = txq->nb_tx_desc;
+
+       qinfo->conf.tx_thresh.pthresh = txq->pthresh;
+       qinfo->conf.tx_thresh.hthresh = txq->hthresh;
+       qinfo->conf.tx_thresh.wthresh = txq->wthresh;
+       qinfo->conf.tx_free_thresh = txq->tx_free_thresh;
+       qinfo->conf.tx_rs_thresh = txq->tx_rs_thresh;
+}