New upstream version 17.11-rc3
[deb_dpdk.git] / drivers / net / mlx4 / mlx4_rxtx.c
diff --git a/drivers/net/mlx4/mlx4_rxtx.c b/drivers/net/mlx4/mlx4_rxtx.c
new file mode 100644 (file)
index 0000000..3985e06
--- /dev/null
@@ -0,0 +1,1071 @@
+/*-
+ *   BSD LICENSE
+ *
+ *   Copyright 2017 6WIND S.A.
+ *   Copyright 2017 Mellanox
+ *
+ *   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 6WIND S.A. 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.
+ */
+
+/**
+ * @file
+ * Data plane functions for mlx4 driver.
+ */
+
+#include <assert.h>
+#include <stdint.h>
+#include <string.h>
+
+/* Verbs headers do not support -pedantic. */
+#ifdef PEDANTIC
+#pragma GCC diagnostic ignored "-Wpedantic"
+#endif
+#include <infiniband/verbs.h>
+#ifdef PEDANTIC
+#pragma GCC diagnostic error "-Wpedantic"
+#endif
+
+#include <rte_branch_prediction.h>
+#include <rte_common.h>
+#include <rte_io.h>
+#include <rte_mbuf.h>
+#include <rte_mempool.h>
+#include <rte_prefetch.h>
+
+#include "mlx4.h"
+#include "mlx4_prm.h"
+#include "mlx4_rxtx.h"
+#include "mlx4_utils.h"
+
+#define WQE_ONE_DATA_SEG_SIZE \
+       (sizeof(struct mlx4_wqe_ctrl_seg) + sizeof(struct mlx4_wqe_data_seg))
+
+/**
+ * Pointer-value pair structure used in tx_post_send for saving the first
+ * DWORD (32 byte) of a TXBB.
+ */
+struct pv {
+       volatile struct mlx4_wqe_data_seg *dseg;
+       uint32_t val;
+};
+
+/** A table to translate Rx completion flags to packet type. */
+uint32_t mlx4_ptype_table[0x100] __rte_cache_aligned = {
+       /*
+        * The index to the array should have:
+        *  bit[7] - MLX4_CQE_L2_TUNNEL
+        *  bit[6] - MLX4_CQE_L2_TUNNEL_IPV4
+        *  bit[5] - MLX4_CQE_STATUS_UDP
+        *  bit[4] - MLX4_CQE_STATUS_TCP
+        *  bit[3] - MLX4_CQE_STATUS_IPV4OPT
+        *  bit[2] - MLX4_CQE_STATUS_IPV6
+        *  bit[1] - MLX4_CQE_STATUS_IPV4F
+        *  bit[0] - MLX4_CQE_STATUS_IPV4
+        * giving a total of up to 256 entries.
+        */
+       [0x00] = RTE_PTYPE_L2_ETHER,
+       [0x01] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT_UNKNOWN,
+       [0x02] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT_UNKNOWN |
+                    RTE_PTYPE_L4_FRAG,
+       [0x03] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT_UNKNOWN |
+                    RTE_PTYPE_L4_FRAG,
+       [0x04] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV6_EXT_UNKNOWN,
+       [0x09] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT,
+       [0x0a] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT |
+                    RTE_PTYPE_L4_FRAG,
+       [0x11] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT_UNKNOWN |
+                    RTE_PTYPE_L4_TCP,
+       [0x12] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT_UNKNOWN |
+                    RTE_PTYPE_L4_TCP,
+       [0x14] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV6_EXT_UNKNOWN |
+                    RTE_PTYPE_L4_TCP,
+       [0x18] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT |
+                    RTE_PTYPE_L4_TCP,
+       [0x19] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT |
+                    RTE_PTYPE_L4_TCP,
+       [0x1a] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT |
+                    RTE_PTYPE_L4_TCP,
+       [0x21] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT_UNKNOWN |
+                    RTE_PTYPE_L4_UDP,
+       [0x22] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT_UNKNOWN |
+                    RTE_PTYPE_L4_UDP,
+       [0x24] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV6_EXT_UNKNOWN |
+                    RTE_PTYPE_L4_UDP,
+       [0x28] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT |
+                    RTE_PTYPE_L4_UDP,
+       [0x29] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT |
+                    RTE_PTYPE_L4_UDP,
+       [0x2a] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT |
+                    RTE_PTYPE_L4_UDP,
+       /* Tunneled - L3 IPV6 */
+       [0x80] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV6_EXT_UNKNOWN,
+       [0x81] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV6_EXT_UNKNOWN |
+                    RTE_PTYPE_INNER_L3_IPV4_EXT_UNKNOWN,
+       [0x82] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV6_EXT_UNKNOWN |
+                    RTE_PTYPE_INNER_L3_IPV4_EXT_UNKNOWN |
+                    RTE_PTYPE_INNER_L4_FRAG,
+       [0x83] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV6_EXT_UNKNOWN |
+                    RTE_PTYPE_INNER_L3_IPV4_EXT_UNKNOWN |
+                    RTE_PTYPE_INNER_L4_FRAG,
+       [0x84] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV6_EXT_UNKNOWN |
+                    RTE_PTYPE_INNER_L3_IPV6_EXT_UNKNOWN,
+       [0x88] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV6_EXT_UNKNOWN |
+                    RTE_PTYPE_INNER_L3_IPV4_EXT,
+       [0x89] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV6_EXT_UNKNOWN |
+                    RTE_PTYPE_INNER_L3_IPV4_EXT,
+       [0x8a] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV6_EXT_UNKNOWN |
+                    RTE_PTYPE_INNER_L3_IPV4_EXT | RTE_PTYPE_INNER_L4_FRAG,
+       /* Tunneled - L3 IPV6, TCP */
+       [0x91] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV6_EXT_UNKNOWN |
+                    RTE_PTYPE_INNER_L3_IPV4_EXT_UNKNOWN |
+                    RTE_PTYPE_INNER_L4_TCP,
+       [0x92] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV6_EXT_UNKNOWN |
+                    RTE_PTYPE_INNER_L3_IPV4_EXT_UNKNOWN |
+                    RTE_PTYPE_INNER_L4_FRAG |
+                    RTE_PTYPE_INNER_L4_TCP,
+       [0x93] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV6_EXT_UNKNOWN |
+                    RTE_PTYPE_INNER_L3_IPV4_EXT_UNKNOWN |
+                    RTE_PTYPE_INNER_L4_FRAG |
+                    RTE_PTYPE_INNER_L4_TCP,
+       [0x94] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV6_EXT_UNKNOWN |
+                    RTE_PTYPE_INNER_L3_IPV6_EXT_UNKNOWN |
+                    RTE_PTYPE_INNER_L4_TCP,
+       [0x98] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV6_EXT_UNKNOWN |
+                    RTE_PTYPE_INNER_L3_IPV4_EXT |
+                    RTE_PTYPE_INNER_L4_TCP,
+       [0x99] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV6_EXT_UNKNOWN |
+                    RTE_PTYPE_INNER_L3_IPV4_EXT |
+                    RTE_PTYPE_INNER_L4_TCP,
+       [0x9a] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV6_EXT_UNKNOWN |
+                    RTE_PTYPE_INNER_L3_IPV4_EXT | RTE_PTYPE_INNER_L4_FRAG |
+                    RTE_PTYPE_INNER_L4_TCP,
+       /* Tunneled - L3 IPV6, UDP */
+       [0xa1] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT_UNKNOWN |
+                    RTE_PTYPE_INNER_L3_IPV4_EXT_UNKNOWN |
+                    RTE_PTYPE_INNER_L4_UDP,
+       [0xa2] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT_UNKNOWN |
+                    RTE_PTYPE_INNER_L3_IPV4_EXT_UNKNOWN |
+                    RTE_PTYPE_INNER_L4_FRAG |
+                    RTE_PTYPE_INNER_L4_UDP,
+       [0xa3] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT_UNKNOWN |
+                    RTE_PTYPE_INNER_L3_IPV4_EXT_UNKNOWN |
+                    RTE_PTYPE_INNER_L4_FRAG |
+                    RTE_PTYPE_INNER_L4_UDP,
+       [0xa4] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT_UNKNOWN |
+                    RTE_PTYPE_INNER_L3_IPV6_EXT_UNKNOWN |
+                    RTE_PTYPE_INNER_L4_UDP,
+       [0xa8] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT_UNKNOWN |
+                    RTE_PTYPE_INNER_L3_IPV4_EXT |
+                    RTE_PTYPE_INNER_L4_UDP,
+       [0xa9] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT_UNKNOWN |
+                    RTE_PTYPE_INNER_L3_IPV4_EXT |
+                    RTE_PTYPE_INNER_L4_UDP,
+       [0xaa] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT_UNKNOWN |
+                    RTE_PTYPE_INNER_L3_IPV4_EXT | RTE_PTYPE_INNER_L4_FRAG |
+                    RTE_PTYPE_INNER_L4_UDP,
+       /* Tunneled - L3 IPV4 */
+       [0xc0] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT_UNKNOWN,
+       [0xc1] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT_UNKNOWN |
+                    RTE_PTYPE_INNER_L3_IPV4_EXT_UNKNOWN,
+       [0xc2] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT_UNKNOWN |
+                    RTE_PTYPE_INNER_L3_IPV4_EXT_UNKNOWN |
+                    RTE_PTYPE_INNER_L4_FRAG,
+       [0xc3] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT_UNKNOWN |
+                    RTE_PTYPE_INNER_L3_IPV4_EXT_UNKNOWN |
+                    RTE_PTYPE_INNER_L4_FRAG,
+       [0xc4] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT_UNKNOWN |
+                    RTE_PTYPE_INNER_L3_IPV6_EXT_UNKNOWN,
+       [0xc8] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT_UNKNOWN |
+                    RTE_PTYPE_INNER_L3_IPV4_EXT,
+       [0xc9] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT_UNKNOWN |
+                    RTE_PTYPE_INNER_L3_IPV4_EXT,
+       [0xca] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT_UNKNOWN |
+                    RTE_PTYPE_INNER_L3_IPV4_EXT |
+                    RTE_PTYPE_INNER_L4_FRAG,
+       /* Tunneled - L3 IPV4, TCP */
+       [0xd0] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT_UNKNOWN |
+                    RTE_PTYPE_INNER_L3_IPV6_EXT_UNKNOWN |
+                    RTE_PTYPE_INNER_L4_TCP,
+       [0xd1] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT_UNKNOWN |
+                    RTE_PTYPE_INNER_L3_IPV4_EXT_UNKNOWN |
+                    RTE_PTYPE_INNER_L4_TCP,
+       [0xd2] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT_UNKNOWN |
+                    RTE_PTYPE_INNER_L3_IPV4_EXT_UNKNOWN |
+                    RTE_PTYPE_INNER_L4_FRAG |
+                    RTE_PTYPE_INNER_L4_TCP,
+       [0xd3] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT_UNKNOWN |
+                    RTE_PTYPE_INNER_L3_IPV4_EXT_UNKNOWN |
+                    RTE_PTYPE_INNER_L4_FRAG |
+                    RTE_PTYPE_INNER_L4_TCP,
+       [0xd4] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT_UNKNOWN |
+                    RTE_PTYPE_INNER_L3_IPV6_EXT_UNKNOWN |
+                    RTE_PTYPE_INNER_L4_TCP,
+       [0xd8] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT_UNKNOWN |
+                    RTE_PTYPE_INNER_L3_IPV4_EXT |
+                    RTE_PTYPE_INNER_L4_TCP,
+       [0xd9] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT_UNKNOWN |
+                    RTE_PTYPE_INNER_L3_IPV4_EXT |
+                    RTE_PTYPE_INNER_L4_TCP,
+       [0xda] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT_UNKNOWN |
+                    RTE_PTYPE_INNER_L3_IPV4_EXT | RTE_PTYPE_INNER_L4_FRAG |
+                    RTE_PTYPE_INNER_L4_TCP,
+       /* Tunneled - L3 IPV4, UDP */
+       [0xe0] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT_UNKNOWN |
+                    RTE_PTYPE_INNER_L3_IPV6_EXT_UNKNOWN |
+                    RTE_PTYPE_INNER_L4_UDP,
+       [0xe1] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT_UNKNOWN |
+                    RTE_PTYPE_INNER_L3_IPV4_EXT_UNKNOWN |
+                    RTE_PTYPE_INNER_L4_UDP,
+       [0xe2] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT_UNKNOWN |
+                    RTE_PTYPE_INNER_L3_IPV4_EXT_UNKNOWN |
+                    RTE_PTYPE_INNER_L4_FRAG |
+                    RTE_PTYPE_INNER_L4_UDP,
+       [0xe3] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT_UNKNOWN |
+                    RTE_PTYPE_INNER_L3_IPV4_EXT_UNKNOWN |
+                    RTE_PTYPE_INNER_L4_FRAG |
+                    RTE_PTYPE_INNER_L4_UDP,
+       [0xe4] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT_UNKNOWN |
+                    RTE_PTYPE_INNER_L3_IPV6_EXT_UNKNOWN |
+                    RTE_PTYPE_INNER_L4_UDP,
+       [0xe8] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT_UNKNOWN |
+                    RTE_PTYPE_INNER_L3_IPV4_EXT | RTE_PTYPE_INNER_L4_UDP,
+       [0xe9] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT_UNKNOWN |
+                    RTE_PTYPE_INNER_L3_IPV4_EXT | RTE_PTYPE_INNER_L4_UDP,
+       [0xea] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT_UNKNOWN |
+                    RTE_PTYPE_INNER_L3_IPV4_EXT | RTE_PTYPE_INNER_L4_FRAG |
+                    RTE_PTYPE_INNER_L4_UDP,
+};
+
+/**
+ * Stamp a WQE so it won't be reused by the HW.
+ *
+ * Routine is used when freeing WQE used by the chip or when failing
+ * building an WQ entry has failed leaving partial information on the queue.
+ *
+ * @param sq
+ *   Pointer to the SQ structure.
+ * @param index
+ *   Index of the freed WQE.
+ * @param num_txbbs
+ *   Number of blocks to stamp.
+ *   If < 0 the routine will use the size written in the WQ entry.
+ * @param owner
+ *   The value of the WQE owner bit to use in the stamp.
+ *
+ * @return
+ *   The number of Tx basic blocs (TXBB) the WQE contained.
+ */
+static int
+mlx4_txq_stamp_freed_wqe(struct mlx4_sq *sq, uint16_t index, uint8_t owner)
+{
+       uint32_t stamp = rte_cpu_to_be_32(MLX4_SQ_STAMP_VAL |
+                                         (!!owner << MLX4_SQ_STAMP_SHIFT));
+       volatile uint8_t *wqe = mlx4_get_send_wqe(sq,
+                                               (index & sq->txbb_cnt_mask));
+       volatile uint32_t *ptr = (volatile uint32_t *)wqe;
+       int i;
+       int txbbs_size;
+       int num_txbbs;
+
+       /* Extract the size from the control segment of the WQE. */
+       num_txbbs = MLX4_SIZE_TO_TXBBS((((volatile struct mlx4_wqe_ctrl_seg *)
+                                        wqe)->fence_size & 0x3f) << 4);
+       txbbs_size = num_txbbs * MLX4_TXBB_SIZE;
+       /* Optimize the common case when there is no wrap-around. */
+       if (wqe + txbbs_size <= sq->eob) {
+               /* Stamp the freed descriptor. */
+               for (i = 0; i < txbbs_size; i += MLX4_SQ_STAMP_STRIDE) {
+                       *ptr = stamp;
+                       ptr += MLX4_SQ_STAMP_DWORDS;
+               }
+       } else {
+               /* Stamp the freed descriptor. */
+               for (i = 0; i < txbbs_size; i += MLX4_SQ_STAMP_STRIDE) {
+                       *ptr = stamp;
+                       ptr += MLX4_SQ_STAMP_DWORDS;
+                       if ((volatile uint8_t *)ptr >= sq->eob) {
+                               ptr = (volatile uint32_t *)sq->buf;
+                               stamp ^= RTE_BE32(0x80000000);
+                       }
+               }
+       }
+       return num_txbbs;
+}
+
+/**
+ * Manage Tx completions.
+ *
+ * When sending a burst, mlx4_tx_burst() posts several WRs.
+ * To improve performance, a completion event is only required once every
+ * MLX4_PMD_TX_PER_COMP_REQ sends. Doing so discards completion information
+ * for other WRs, but this information would not be used anyway.
+ *
+ * @param txq
+ *   Pointer to Tx queue structure.
+ *
+ * @return
+ *   0 on success, -1 on failure.
+ */
+static int
+mlx4_txq_complete(struct txq *txq, const unsigned int elts_n,
+                                 struct mlx4_sq *sq)
+{
+       unsigned int elts_comp = txq->elts_comp;
+       unsigned int elts_tail = txq->elts_tail;
+       struct mlx4_cq *cq = &txq->mcq;
+       volatile struct mlx4_cqe *cqe;
+       uint32_t cons_index = cq->cons_index;
+       uint16_t new_index;
+       uint16_t nr_txbbs = 0;
+       int pkts = 0;
+
+       /*
+        * Traverse over all CQ entries reported and handle each WQ entry
+        * reported by them.
+        */
+       do {
+               cqe = (volatile struct mlx4_cqe *)mlx4_get_cqe(cq, cons_index);
+               if (unlikely(!!(cqe->owner_sr_opcode & MLX4_CQE_OWNER_MASK) ^
+                   !!(cons_index & cq->cqe_cnt)))
+                       break;
+               /*
+                * Make sure we read the CQE after we read the ownership bit.
+                */
+               rte_io_rmb();
+#ifndef NDEBUG
+               if (unlikely((cqe->owner_sr_opcode & MLX4_CQE_OPCODE_MASK) ==
+                            MLX4_CQE_OPCODE_ERROR)) {
+                       volatile struct mlx4_err_cqe *cqe_err =
+                               (volatile struct mlx4_err_cqe *)cqe;
+                       ERROR("%p CQE error - vendor syndrome: 0x%x"
+                             " syndrome: 0x%x\n",
+                             (void *)txq, cqe_err->vendor_err,
+                             cqe_err->syndrome);
+               }
+#endif /* NDEBUG */
+               /* Get WQE index reported in the CQE. */
+               new_index =
+                       rte_be_to_cpu_16(cqe->wqe_index) & sq->txbb_cnt_mask;
+               do {
+                       /* Free next descriptor. */
+                       nr_txbbs +=
+                               mlx4_txq_stamp_freed_wqe(sq,
+                                    (sq->tail + nr_txbbs) & sq->txbb_cnt_mask,
+                                    !!((sq->tail + nr_txbbs) & sq->txbb_cnt));
+                       pkts++;
+               } while (((sq->tail + nr_txbbs) & sq->txbb_cnt_mask) !=
+                        new_index);
+               cons_index++;
+       } while (1);
+       if (unlikely(pkts == 0))
+               return 0;
+       /* Update CQ. */
+       cq->cons_index = cons_index;
+       *cq->set_ci_db = rte_cpu_to_be_32(cq->cons_index & MLX4_CQ_DB_CI_MASK);
+       sq->tail = sq->tail + nr_txbbs;
+       /* Update the list of packets posted for transmission. */
+       elts_comp -= pkts;
+       assert(elts_comp <= txq->elts_comp);
+       /*
+        * Assume completion status is successful as nothing can be done about
+        * it anyway.
+        */
+       elts_tail += pkts;
+       if (elts_tail >= elts_n)
+               elts_tail -= elts_n;
+       txq->elts_tail = elts_tail;
+       txq->elts_comp = elts_comp;
+       return 0;
+}
+
+/**
+ * Get memory pool (MP) from mbuf. If mbuf is indirect, the pool from which
+ * the cloned mbuf is allocated is returned instead.
+ *
+ * @param buf
+ *   Pointer to mbuf.
+ *
+ * @return
+ *   Memory pool where data is located for given mbuf.
+ */
+static struct rte_mempool *
+mlx4_txq_mb2mp(struct rte_mbuf *buf)
+{
+       if (unlikely(RTE_MBUF_INDIRECT(buf)))
+               return rte_mbuf_from_indirect(buf)->pool;
+       return buf->pool;
+}
+
+static int
+mlx4_tx_burst_segs(struct rte_mbuf *buf, struct txq *txq,
+                  volatile struct mlx4_wqe_ctrl_seg **pctrl)
+{
+       int wqe_real_size;
+       int nr_txbbs;
+       struct pv *pv = (struct pv *)txq->bounce_buf;
+       struct mlx4_sq *sq = &txq->msq;
+       uint32_t head_idx = sq->head & sq->txbb_cnt_mask;
+       volatile struct mlx4_wqe_ctrl_seg *ctrl;
+       volatile struct mlx4_wqe_data_seg *dseg;
+       struct rte_mbuf *sbuf;
+       uint32_t lkey;
+       uintptr_t addr;
+       uint32_t byte_count;
+       int pv_counter = 0;
+
+       /* Calculate the needed work queue entry size for this packet. */
+       wqe_real_size = sizeof(volatile struct mlx4_wqe_ctrl_seg) +
+               buf->nb_segs * sizeof(volatile struct mlx4_wqe_data_seg);
+       nr_txbbs = MLX4_SIZE_TO_TXBBS(wqe_real_size);
+       /*
+        * Check that there is room for this WQE in the send queue and that
+        * the WQE size is legal.
+        */
+       if (((sq->head - sq->tail) + nr_txbbs +
+                               sq->headroom_txbbs) >= sq->txbb_cnt ||
+                       nr_txbbs > MLX4_MAX_WQE_TXBBS) {
+               return -1;
+       }
+       /* Get the control and data entries of the WQE. */
+       ctrl = (volatile struct mlx4_wqe_ctrl_seg *)
+                       mlx4_get_send_wqe(sq, head_idx);
+       dseg = (volatile struct mlx4_wqe_data_seg *)
+                       ((uintptr_t)ctrl + sizeof(struct mlx4_wqe_ctrl_seg));
+       *pctrl = ctrl;
+       /* Fill the data segments with buffer information. */
+       for (sbuf = buf; sbuf != NULL; sbuf = sbuf->next, dseg++) {
+               addr = rte_pktmbuf_mtod(sbuf, uintptr_t);
+               rte_prefetch0((volatile void *)addr);
+               /* Handle WQE wraparound. */
+               if (dseg >= (volatile struct mlx4_wqe_data_seg *)sq->eob)
+                       dseg = (volatile struct mlx4_wqe_data_seg *)sq->buf;
+               dseg->addr = rte_cpu_to_be_64(addr);
+               /* Memory region key (big endian) for this memory pool. */
+               lkey = mlx4_txq_mp2mr(txq, mlx4_txq_mb2mp(sbuf));
+               dseg->lkey = rte_cpu_to_be_32(lkey);
+#ifndef NDEBUG
+               /* Calculate the needed work queue entry size for this packet */
+               if (unlikely(dseg->lkey == rte_cpu_to_be_32((uint32_t)-1))) {
+                       /* MR does not exist. */
+                       DEBUG("%p: unable to get MP <-> MR association",
+                                       (void *)txq);
+                       /*
+                        * Restamp entry in case of failure.
+                        * Make sure that size is written correctly
+                        * Note that we give ownership to the SW, not the HW.
+                        */
+                       wqe_real_size = sizeof(struct mlx4_wqe_ctrl_seg) +
+                               buf->nb_segs * sizeof(struct mlx4_wqe_data_seg);
+                       ctrl->fence_size = (wqe_real_size >> 4) & 0x3f;
+                       mlx4_txq_stamp_freed_wqe(sq, head_idx,
+                                       (sq->head & sq->txbb_cnt) ? 0 : 1);
+                       return -1;
+               }
+#endif /* NDEBUG */
+               if (likely(sbuf->data_len)) {
+                       byte_count = rte_cpu_to_be_32(sbuf->data_len);
+               } else {
+                       /*
+                        * Zero length segment is treated as inline segment
+                        * with zero data.
+                        */
+                       byte_count = RTE_BE32(0x80000000);
+               }
+               /*
+                * If the data segment is not at the beginning of a
+                * Tx basic block (TXBB) then write the byte count,
+                * else postpone the writing to just before updating the
+                * control segment.
+                */
+               if ((uintptr_t)dseg & (uintptr_t)(MLX4_TXBB_SIZE - 1)) {
+#if RTE_CACHE_LINE_SIZE < 64
+                       /*
+                        * Need a barrier here before writing the byte_count
+                        * fields to make sure that all the data is visible
+                        * before the byte_count field is set.
+                        * Otherwise, if the segment begins a new cacheline,
+                        * the HCA prefetcher could grab the 64-byte chunk and
+                        * get a valid (!= 0xffffffff) byte count but stale
+                        * data, and end up sending the wrong data.
+                        */
+                       rte_io_wmb();
+#endif /* RTE_CACHE_LINE_SIZE */
+                       dseg->byte_count = byte_count;
+               } else {
+                       /*
+                        * This data segment starts at the beginning of a new
+                        * TXBB, so we need to postpone its byte_count writing
+                        * for later.
+                        */
+                       pv[pv_counter].dseg = dseg;
+                       pv[pv_counter++].val = byte_count;
+               }
+       }
+       /* Write the first DWORD of each TXBB save earlier. */
+       if (pv_counter) {
+               /* Need a barrier here before writing the byte_count. */
+               rte_io_wmb();
+               for (--pv_counter; pv_counter  >= 0; pv_counter--)
+                       pv[pv_counter].dseg->byte_count = pv[pv_counter].val;
+       }
+       /* Fill the control parameters for this packet. */
+       ctrl->fence_size = (wqe_real_size >> 4) & 0x3f;
+       return nr_txbbs;
+}
+
+/**
+ * DPDK callback for Tx.
+ *
+ * @param dpdk_txq
+ *   Generic pointer to Tx queue structure.
+ * @param[in] pkts
+ *   Packets to transmit.
+ * @param pkts_n
+ *   Number of packets in array.
+ *
+ * @return
+ *   Number of packets successfully transmitted (<= pkts_n).
+ */
+uint16_t
+mlx4_tx_burst(void *dpdk_txq, struct rte_mbuf **pkts, uint16_t pkts_n)
+{
+       struct txq *txq = (struct txq *)dpdk_txq;
+       unsigned int elts_head = txq->elts_head;
+       const unsigned int elts_n = txq->elts_n;
+       unsigned int bytes_sent = 0;
+       unsigned int i;
+       unsigned int max;
+       struct mlx4_sq *sq = &txq->msq;
+       int nr_txbbs;
+
+       assert(txq->elts_comp_cd != 0);
+       if (likely(txq->elts_comp != 0))
+               mlx4_txq_complete(txq, elts_n, sq);
+       max = (elts_n - (elts_head - txq->elts_tail));
+       if (max > elts_n)
+               max -= elts_n;
+       assert(max >= 1);
+       assert(max <= elts_n);
+       /* Always leave one free entry in the ring. */
+       --max;
+       if (max > pkts_n)
+               max = pkts_n;
+       for (i = 0; (i != max); ++i) {
+               struct rte_mbuf *buf = pkts[i];
+               unsigned int elts_head_next =
+                       (((elts_head + 1) == elts_n) ? 0 : elts_head + 1);
+               struct txq_elt *elt_next = &(*txq->elts)[elts_head_next];
+               struct txq_elt *elt = &(*txq->elts)[elts_head];
+               uint32_t owner_opcode = MLX4_OPCODE_SEND;
+               volatile struct mlx4_wqe_ctrl_seg *ctrl;
+               volatile struct mlx4_wqe_data_seg *dseg;
+               union {
+                       uint32_t flags;
+                       uint16_t flags16[2];
+               } srcrb;
+               uint32_t head_idx = sq->head & sq->txbb_cnt_mask;
+               uint32_t lkey;
+               uintptr_t addr;
+
+               /* Clean up old buffer. */
+               if (likely(elt->buf != NULL)) {
+                       struct rte_mbuf *tmp = elt->buf;
+
+#ifndef NDEBUG
+                       /* Poisoning. */
+                       memset(elt, 0x66, sizeof(*elt));
+#endif
+                       /* Faster than rte_pktmbuf_free(). */
+                       do {
+                               struct rte_mbuf *next = tmp->next;
+
+                               rte_pktmbuf_free_seg(tmp);
+                               tmp = next;
+                       } while (tmp != NULL);
+               }
+               RTE_MBUF_PREFETCH_TO_FREE(elt_next->buf);
+               if (buf->nb_segs == 1) {
+                       /*
+                        * Check that there is room for this WQE in the send
+                        * queue and that the WQE size is legal
+                        */
+                       if (((sq->head - sq->tail) + 1 + sq->headroom_txbbs) >=
+                            sq->txbb_cnt || 1 > MLX4_MAX_WQE_TXBBS) {
+                               elt->buf = NULL;
+                               break;
+                       }
+                       /* Get the control and data entries of the WQE. */
+                       ctrl = (volatile struct mlx4_wqe_ctrl_seg *)
+                                       mlx4_get_send_wqe(sq, head_idx);
+                       dseg = (volatile struct mlx4_wqe_data_seg *)
+                                       ((uintptr_t)ctrl +
+                                       sizeof(struct mlx4_wqe_ctrl_seg));
+                       addr = rte_pktmbuf_mtod(buf, uintptr_t);
+                       rte_prefetch0((volatile void *)addr);
+                       /* Handle WQE wraparound. */
+                       if (dseg >=
+                               (volatile struct mlx4_wqe_data_seg *)sq->eob)
+                               dseg = (volatile struct mlx4_wqe_data_seg *)
+                                               sq->buf;
+                       dseg->addr = rte_cpu_to_be_64(addr);
+                       /* Memory region key (big endian). */
+                       lkey = mlx4_txq_mp2mr(txq, mlx4_txq_mb2mp(buf));
+                       dseg->lkey = rte_cpu_to_be_32(lkey);
+#ifndef NDEBUG
+                       if (unlikely(dseg->lkey ==
+                               rte_cpu_to_be_32((uint32_t)-1))) {
+                               /* MR does not exist. */
+                               DEBUG("%p: unable to get MP <-> MR association",
+                                     (void *)txq);
+                               /*
+                                * Restamp entry in case of failure.
+                                * Make sure that size is written correctly
+                                * Note that we give ownership to the SW,
+                                * not the HW.
+                                */
+                               ctrl->fence_size =
+                                       (WQE_ONE_DATA_SEG_SIZE >> 4) & 0x3f;
+                               mlx4_txq_stamp_freed_wqe(sq, head_idx,
+                                            (sq->head & sq->txbb_cnt) ? 0 : 1);
+                               elt->buf = NULL;
+                               break;
+                       }
+#endif /* NDEBUG */
+                       /* Never be TXBB aligned, no need compiler barrier. */
+                       dseg->byte_count = rte_cpu_to_be_32(buf->data_len);
+                       /* Fill the control parameters for this packet. */
+                       ctrl->fence_size = (WQE_ONE_DATA_SEG_SIZE >> 4) & 0x3f;
+                       nr_txbbs = 1;
+               } else {
+                       nr_txbbs = mlx4_tx_burst_segs(buf, txq, &ctrl);
+                       if (nr_txbbs < 0) {
+                               elt->buf = NULL;
+                               break;
+                       }
+               }
+               /*
+                * For raw Ethernet, the SOLICIT flag is used to indicate
+                * that no ICRC should be calculated.
+                */
+               txq->elts_comp_cd -= nr_txbbs;
+               if (unlikely(txq->elts_comp_cd <= 0)) {
+                       txq->elts_comp_cd = txq->elts_comp_cd_init;
+                       srcrb.flags = RTE_BE32(MLX4_WQE_CTRL_SOLICIT |
+                                              MLX4_WQE_CTRL_CQ_UPDATE);
+               } else {
+                       srcrb.flags = RTE_BE32(MLX4_WQE_CTRL_SOLICIT);
+               }
+               /* Enable HW checksum offload if requested */
+               if (txq->csum &&
+                   (buf->ol_flags &
+                    (PKT_TX_IP_CKSUM | PKT_TX_TCP_CKSUM | PKT_TX_UDP_CKSUM))) {
+                       const uint64_t is_tunneled = (buf->ol_flags &
+                                                     (PKT_TX_TUNNEL_GRE |
+                                                      PKT_TX_TUNNEL_VXLAN));
+
+                       if (is_tunneled && txq->csum_l2tun) {
+                               owner_opcode |= MLX4_WQE_CTRL_IIP_HDR_CSUM |
+                                               MLX4_WQE_CTRL_IL4_HDR_CSUM;
+                               if (buf->ol_flags & PKT_TX_OUTER_IP_CKSUM)
+                                       srcrb.flags |=
+                                           RTE_BE32(MLX4_WQE_CTRL_IP_HDR_CSUM);
+                       } else {
+                               srcrb.flags |=
+                                       RTE_BE32(MLX4_WQE_CTRL_IP_HDR_CSUM |
+                                               MLX4_WQE_CTRL_TCP_UDP_CSUM);
+                       }
+               }
+               if (txq->lb) {
+                       /*
+                        * Copy destination MAC address to the WQE, this allows
+                        * loopback in eSwitch, so that VFs and PF can
+                        * communicate with each other.
+                        */
+                       srcrb.flags16[0] = *(rte_pktmbuf_mtod(buf, uint16_t *));
+                       ctrl->imm = *(rte_pktmbuf_mtod_offset(buf, uint32_t *,
+                                             sizeof(uint16_t)));
+               } else {
+                       ctrl->imm = 0;
+               }
+               ctrl->srcrb_flags = srcrb.flags;
+               /*
+                * Make sure descriptor is fully written before
+                * setting ownership bit (because HW can start
+                * executing as soon as we do).
+                */
+               rte_io_wmb();
+               ctrl->owner_opcode = rte_cpu_to_be_32(owner_opcode |
+                                             ((sq->head & sq->txbb_cnt) ?
+                                                      MLX4_BIT_WQE_OWN : 0));
+               sq->head += nr_txbbs;
+               elt->buf = buf;
+               bytes_sent += buf->pkt_len;
+               elts_head = elts_head_next;
+       }
+       /* Take a shortcut if nothing must be sent. */
+       if (unlikely(i == 0))
+               return 0;
+       /* Increment send statistics counters. */
+       txq->stats.opackets += i;
+       txq->stats.obytes += bytes_sent;
+       /* Make sure that descriptors are written before doorbell record. */
+       rte_wmb();
+       /* Ring QP doorbell. */
+       rte_write32(txq->msq.doorbell_qpn, txq->msq.db);
+       txq->elts_head = elts_head;
+       txq->elts_comp += i;
+       return i;
+}
+
+/**
+ * Translate Rx completion flags to packet type.
+ *
+ * @param[in] cqe
+ *   Pointer to CQE.
+ *
+ * @return
+ *   Packet type for struct rte_mbuf.
+ */
+static inline uint32_t
+rxq_cq_to_pkt_type(volatile struct mlx4_cqe *cqe)
+{
+       uint8_t idx = 0;
+       uint32_t pinfo = rte_be_to_cpu_32(cqe->vlan_my_qpn);
+       uint32_t status = rte_be_to_cpu_32(cqe->status);
+
+       /*
+        * The index to the array should have:
+        *  bit[7] - MLX4_CQE_L2_TUNNEL
+        *  bit[6] - MLX4_CQE_L2_TUNNEL_IPV4
+        */
+       if (!(pinfo & MLX4_CQE_L2_VLAN_MASK) && (pinfo & MLX4_CQE_L2_TUNNEL))
+               idx |= ((pinfo & MLX4_CQE_L2_TUNNEL) >> 20) |
+                      ((pinfo & MLX4_CQE_L2_TUNNEL_IPV4) >> 19);
+       /*
+        * The index to the array should have:
+        *  bit[5] - MLX4_CQE_STATUS_UDP
+        *  bit[4] - MLX4_CQE_STATUS_TCP
+        *  bit[3] - MLX4_CQE_STATUS_IPV4OPT
+        *  bit[2] - MLX4_CQE_STATUS_IPV6
+        *  bit[1] - MLX4_CQE_STATUS_IPV4F
+        *  bit[0] - MLX4_CQE_STATUS_IPV4
+        * giving a total of up to 256 entries.
+        */
+       idx |= ((status & MLX4_CQE_STATUS_PTYPE_MASK) >> 22);
+       return mlx4_ptype_table[idx];
+}
+
+/**
+ * Translate Rx completion flags to offload flags.
+ *
+ * @param flags
+ *   Rx completion flags returned by mlx4_cqe_flags().
+ * @param csum
+ *   Whether Rx checksums are enabled.
+ * @param csum_l2tun
+ *   Whether Rx L2 tunnel checksums are enabled.
+ *
+ * @return
+ *   Offload flags (ol_flags) in mbuf format.
+ */
+static inline uint32_t
+rxq_cq_to_ol_flags(uint32_t flags, int csum, int csum_l2tun)
+{
+       uint32_t ol_flags = 0;
+
+       if (csum)
+               ol_flags |=
+                       mlx4_transpose(flags,
+                                      MLX4_CQE_STATUS_IP_HDR_CSUM_OK,
+                                      PKT_RX_IP_CKSUM_GOOD) |
+                       mlx4_transpose(flags,
+                                      MLX4_CQE_STATUS_TCP_UDP_CSUM_OK,
+                                      PKT_RX_L4_CKSUM_GOOD);
+       if ((flags & MLX4_CQE_L2_TUNNEL) && csum_l2tun)
+               ol_flags |=
+                       mlx4_transpose(flags,
+                                      MLX4_CQE_L2_TUNNEL_IPOK,
+                                      PKT_RX_IP_CKSUM_GOOD) |
+                       mlx4_transpose(flags,
+                                      MLX4_CQE_L2_TUNNEL_L4_CSUM,
+                                      PKT_RX_L4_CKSUM_GOOD);
+       return ol_flags;
+}
+
+/**
+ * Extract checksum information from CQE flags.
+ *
+ * @param cqe
+ *   Pointer to CQE structure.
+ * @param csum
+ *   Whether Rx checksums are enabled.
+ * @param csum_l2tun
+ *   Whether Rx L2 tunnel checksums are enabled.
+ *
+ * @return
+ *   CQE checksum information.
+ */
+static inline uint32_t
+mlx4_cqe_flags(volatile struct mlx4_cqe *cqe, int csum, int csum_l2tun)
+{
+       uint32_t flags = 0;
+
+       /*
+        * The relevant bits are in different locations on their
+        * CQE fields therefore we can join them in one 32bit
+        * variable.
+        */
+       if (csum)
+               flags = (rte_be_to_cpu_32(cqe->status) &
+                        MLX4_CQE_STATUS_IPV4_CSUM_OK);
+       if (csum_l2tun)
+               flags |= (rte_be_to_cpu_32(cqe->vlan_my_qpn) &
+                         (MLX4_CQE_L2_TUNNEL |
+                          MLX4_CQE_L2_TUNNEL_IPOK |
+                          MLX4_CQE_L2_TUNNEL_L4_CSUM |
+                          MLX4_CQE_L2_TUNNEL_IPV4));
+       return flags;
+}
+
+/**
+ * Poll one CQE from CQ.
+ *
+ * @param rxq
+ *   Pointer to the receive queue structure.
+ * @param[out] out
+ *   Just polled CQE.
+ *
+ * @return
+ *   Number of bytes of the CQE, 0 in case there is no completion.
+ */
+static unsigned int
+mlx4_cq_poll_one(struct rxq *rxq, volatile struct mlx4_cqe **out)
+{
+       int ret = 0;
+       volatile struct mlx4_cqe *cqe = NULL;
+       struct mlx4_cq *cq = &rxq->mcq;
+
+       cqe = (volatile struct mlx4_cqe *)mlx4_get_cqe(cq, cq->cons_index);
+       if (!!(cqe->owner_sr_opcode & MLX4_CQE_OWNER_MASK) ^
+           !!(cq->cons_index & cq->cqe_cnt))
+               goto out;
+       /*
+        * Make sure we read CQ entry contents after we've checked the
+        * ownership bit.
+        */
+       rte_rmb();
+       assert(!(cqe->owner_sr_opcode & MLX4_CQE_IS_SEND_MASK));
+       assert((cqe->owner_sr_opcode & MLX4_CQE_OPCODE_MASK) !=
+              MLX4_CQE_OPCODE_ERROR);
+       ret = rte_be_to_cpu_32(cqe->byte_cnt);
+       ++cq->cons_index;
+out:
+       *out = cqe;
+       return ret;
+}
+
+/**
+ * DPDK callback for Rx with scattered packets support.
+ *
+ * @param dpdk_rxq
+ *   Generic pointer to Rx queue structure.
+ * @param[out] pkts
+ *   Array to store received packets.
+ * @param pkts_n
+ *   Maximum number of packets in array.
+ *
+ * @return
+ *   Number of packets successfully received (<= pkts_n).
+ */
+uint16_t
+mlx4_rx_burst(void *dpdk_rxq, struct rte_mbuf **pkts, uint16_t pkts_n)
+{
+       struct rxq *rxq = dpdk_rxq;
+       const uint32_t wr_cnt = (1 << rxq->elts_n) - 1;
+       const uint16_t sges_n = rxq->sges_n;
+       struct rte_mbuf *pkt = NULL;
+       struct rte_mbuf *seg = NULL;
+       unsigned int i = 0;
+       uint32_t rq_ci = rxq->rq_ci << sges_n;
+       int len = 0;
+
+       while (pkts_n) {
+               volatile struct mlx4_cqe *cqe;
+               uint32_t idx = rq_ci & wr_cnt;
+               struct rte_mbuf *rep = (*rxq->elts)[idx];
+               volatile struct mlx4_wqe_data_seg *scat = &(*rxq->wqes)[idx];
+
+               /* Update the 'next' pointer of the previous segment. */
+               if (pkt)
+                       seg->next = rep;
+               seg = rep;
+               rte_prefetch0(seg);
+               rte_prefetch0(scat);
+               rep = rte_mbuf_raw_alloc(rxq->mp);
+               if (unlikely(rep == NULL)) {
+                       ++rxq->stats.rx_nombuf;
+                       if (!pkt) {
+                               /*
+                                * No buffers before we even started,
+                                * bail out silently.
+                                */
+                               break;
+                       }
+                       while (pkt != seg) {
+                               assert(pkt != (*rxq->elts)[idx]);
+                               rep = pkt->next;
+                               pkt->next = NULL;
+                               pkt->nb_segs = 1;
+                               rte_mbuf_raw_free(pkt);
+                               pkt = rep;
+                       }
+                       break;
+               }
+               if (!pkt) {
+                       /* Looking for the new packet. */
+                       len = mlx4_cq_poll_one(rxq, &cqe);
+                       if (!len) {
+                               rte_mbuf_raw_free(rep);
+                               break;
+                       }
+                       if (unlikely(len < 0)) {
+                               /* Rx error, packet is likely too large. */
+                               rte_mbuf_raw_free(rep);
+                               ++rxq->stats.idropped;
+                               goto skip;
+                       }
+                       pkt = seg;
+                       /* Update packet information. */
+                       pkt->packet_type = rxq_cq_to_pkt_type(cqe);
+                       pkt->ol_flags = 0;
+                       pkt->pkt_len = len;
+                       if (rxq->csum | rxq->csum_l2tun) {
+                               uint32_t flags =
+                                       mlx4_cqe_flags(cqe,
+                                                      rxq->csum,
+                                                      rxq->csum_l2tun);
+
+                               pkt->ol_flags =
+                                       rxq_cq_to_ol_flags(flags,
+                                                          rxq->csum,
+                                                          rxq->csum_l2tun);
+                       }
+               }
+               rep->nb_segs = 1;
+               rep->port = rxq->port_id;
+               rep->data_len = seg->data_len;
+               rep->data_off = seg->data_off;
+               (*rxq->elts)[idx] = rep;
+               /*
+                * Fill NIC descriptor with the new buffer. The lkey and size
+                * of the buffers are already known, only the buffer address
+                * changes.
+                */
+               scat->addr = rte_cpu_to_be_64(rte_pktmbuf_mtod(rep, uintptr_t));
+               if (len > seg->data_len) {
+                       len -= seg->data_len;
+                       ++pkt->nb_segs;
+                       ++rq_ci;
+                       continue;
+               }
+               /* The last segment. */
+               seg->data_len = len;
+               /* Increment bytes counter. */
+               rxq->stats.ibytes += pkt->pkt_len;
+               /* Return packet. */
+               *(pkts++) = pkt;
+               pkt = NULL;
+               --pkts_n;
+               ++i;
+skip:
+               /* Align consumer index to the next stride. */
+               rq_ci >>= sges_n;
+               ++rq_ci;
+               rq_ci <<= sges_n;
+       }
+       if (unlikely(i == 0 && (rq_ci >> sges_n) == rxq->rq_ci))
+               return 0;
+       /* Update the consumer index. */
+       rxq->rq_ci = rq_ci >> sges_n;
+       rte_wmb();
+       *rxq->rq_db = rte_cpu_to_be_32(rxq->rq_ci);
+       *rxq->mcq.set_ci_db =
+               rte_cpu_to_be_32(rxq->mcq.cons_index & MLX4_CQ_DB_CI_MASK);
+       /* Increment packets counter. */
+       rxq->stats.ipackets += i;
+       return i;
+}
+
+/**
+ * Dummy DPDK callback for Tx.
+ *
+ * This function is used to temporarily replace the real callback during
+ * unsafe control operations on the queue, or in case of error.
+ *
+ * @param dpdk_txq
+ *   Generic pointer to Tx queue structure.
+ * @param[in] pkts
+ *   Packets to transmit.
+ * @param pkts_n
+ *   Number of packets in array.
+ *
+ * @return
+ *   Number of packets successfully transmitted (<= pkts_n).
+ */
+uint16_t
+mlx4_tx_burst_removed(void *dpdk_txq, struct rte_mbuf **pkts, uint16_t pkts_n)
+{
+       (void)dpdk_txq;
+       (void)pkts;
+       (void)pkts_n;
+       return 0;
+}
+
+/**
+ * Dummy DPDK callback for Rx.
+ *
+ * This function is used to temporarily replace the real callback during
+ * unsafe control operations on the queue, or in case of error.
+ *
+ * @param dpdk_rxq
+ *   Generic pointer to Rx queue structure.
+ * @param[out] pkts
+ *   Array to store received packets.
+ * @param pkts_n
+ *   Maximum number of packets in array.
+ *
+ * @return
+ *   Number of packets successfully received (<= pkts_n).
+ */
+uint16_t
+mlx4_rx_burst_removed(void *dpdk_rxq, struct rte_mbuf **pkts, uint16_t pkts_n)
+{
+       (void)dpdk_rxq;
+       (void)pkts;
+       (void)pkts_n;
+       return 0;
+}