net/mlx4: fix Rx packet type offloads
[dpdk.git] / drivers / net / mlx4 / mlx4_rxtx.c
index 38b87a0..06f57cc 100644 (file)
@@ -37,7 +37,6 @@
  */
 
 #include <assert.h>
-#include <inttypes.h>
 #include <stdint.h>
 #include <string.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 {
-       struct mlx4_wqe_data_seg *dseg;
+       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.
  *
@@ -95,14 +284,15 @@ 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));
-       uint8_t *wqe = mlx4_get_send_wqe(sq, (index & sq->txbb_cnt_mask));
-       uint32_t *ptr = (uint32_t *)wqe;
+       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((((struct mlx4_wqe_ctrl_seg *)
+       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. */
@@ -117,8 +307,8 @@ mlx4_txq_stamp_freed_wqe(struct mlx4_sq *sq, uint16_t index, uint8_t owner)
                for (i = 0; i < txbbs_size; i += MLX4_SQ_STAMP_STRIDE) {
                        *ptr = stamp;
                        ptr += MLX4_SQ_STAMP_DWORDS;
-                       if ((uint8_t *)ptr >= sq->eob) {
-                               ptr = (uint32_t *)sq->buf;
+                       if ((volatile uint8_t *)ptr >= sq->eob) {
+                               ptr = (volatile uint32_t *)sq->buf;
                                stamp ^= RTE_BE32(0x80000000);
                        }
                }
@@ -141,43 +331,42 @@ mlx4_txq_stamp_freed_wqe(struct mlx4_sq *sq, uint16_t index, uint8_t owner)
  *   0 on success, -1 on failure.
  */
 static int
-mlx4_txq_complete(struct txq *txq)
+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;
-       const unsigned int elts_n = txq->elts_n;
        struct mlx4_cq *cq = &txq->mcq;
-       struct mlx4_sq *sq = &txq->msq;
-       struct mlx4_cqe *cqe;
+       volatile struct mlx4_cqe *cqe;
        uint32_t cons_index = cq->cons_index;
        uint16_t new_index;
        uint16_t nr_txbbs = 0;
        int pkts = 0;
 
-       if (unlikely(elts_comp == 0))
-               return 0;
        /*
         * Traverse over all CQ entries reported and handle each WQ entry
         * reported by them.
         */
        do {
-               cqe = (struct mlx4_cqe *)mlx4_get_cqe(cq, cons_index);
+               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_rmb();
+               rte_io_rmb();
+#ifndef NDEBUG
                if (unlikely((cqe->owner_sr_opcode & MLX4_CQE_OPCODE_MASK) ==
                             MLX4_CQE_OPCODE_ERROR)) {
-                       struct mlx4_err_cqe *cqe_err =
-                               (struct mlx4_err_cqe *)cqe;
+                       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;
@@ -194,14 +383,9 @@ mlx4_txq_complete(struct txq *txq)
        } while (1);
        if (unlikely(pkts == 0))
                return 0;
-       /*
-        * Update CQ.
-        * To prevent CQ overflow we first update CQ consumer and only then
-        * the ring consumer.
-        */
+       /* Update CQ. */
        cq->cons_index = cons_index;
-       *cq->set_ci_db = rte_cpu_to_be_32(cq->cons_index & 0xffffff);
-       rte_wmb();
+       *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;
@@ -236,139 +420,74 @@ mlx4_txq_mb2mp(struct rte_mbuf *buf)
        return buf->pool;
 }
 
-/**
- * Get memory region (MR) <-> memory pool (MP) association from txq->mp2mr[].
- * Add MP to txq->mp2mr[] if it's not registered yet. If mp2mr[] is full,
- * remove an entry first.
- *
- * @param txq
- *   Pointer to Tx queue structure.
- * @param[in] mp
- *   Memory pool for which a memory region lkey must be returned.
- *
- * @return
- *   mr->lkey on success, (uint32_t)-1 on failure.
- */
-uint32_t
-mlx4_txq_mp2mr(struct txq *txq, struct rte_mempool *mp)
-{
-       unsigned int i;
-       struct ibv_mr *mr;
-
-       for (i = 0; (i != RTE_DIM(txq->mp2mr)); ++i) {
-               if (unlikely(txq->mp2mr[i].mp == NULL)) {
-                       /* Unknown MP, add a new MR for it. */
-                       break;
-               }
-               if (txq->mp2mr[i].mp == mp) {
-                       assert(txq->mp2mr[i].lkey != (uint32_t)-1);
-                       assert(txq->mp2mr[i].mr->lkey == txq->mp2mr[i].lkey);
-                       return txq->mp2mr[i].lkey;
-               }
-       }
-       /* Add a new entry, register MR first. */
-       DEBUG("%p: discovered new memory pool \"%s\" (%p)",
-             (void *)txq, mp->name, (void *)mp);
-       mr = mlx4_mp2mr(txq->priv->pd, mp);
-       if (unlikely(mr == NULL)) {
-               DEBUG("%p: unable to configure MR, ibv_reg_mr() failed.",
-                     (void *)txq);
-               return (uint32_t)-1;
-       }
-       if (unlikely(i == RTE_DIM(txq->mp2mr))) {
-               /* Table is full, remove oldest entry. */
-               DEBUG("%p: MR <-> MP table full, dropping oldest entry.",
-                     (void *)txq);
-               --i;
-               claim_zero(ibv_dereg_mr(txq->mp2mr[0].mr));
-               memmove(&txq->mp2mr[0], &txq->mp2mr[1],
-                       (sizeof(txq->mp2mr) - sizeof(txq->mp2mr[0])));
-       }
-       /* Store the new entry. */
-       txq->mp2mr[i].mp = mp;
-       txq->mp2mr[i].mr = mr;
-       txq->mp2mr[i].lkey = mr->lkey;
-       DEBUG("%p: new MR lkey for MP \"%s\" (%p): 0x%08" PRIu32,
-             (void *)txq, mp->name, (void *)mp, txq->mp2mr[i].lkey);
-       return txq->mp2mr[i].lkey;
-}
-
-/**
- * Posts a single work request to a send queue.
- *
- * @param txq
- *   Target Tx queue.
- * @param pkt
- *   Packet to transmit.
- *
- * @return
- *   0 on success, negative errno value otherwise and rte_errno is set.
- */
-static inline int
-mlx4_post_send(struct txq *txq, struct rte_mbuf *pkt)
+static int
+mlx4_tx_burst_segs(struct rte_mbuf *buf, struct txq *txq,
+                  volatile struct mlx4_wqe_ctrl_seg **pctrl)
 {
-       struct mlx4_wqe_ctrl_seg *ctrl;
-       struct mlx4_wqe_data_seg *dseg;
+       int wqe_real_size;
+       int nr_txbbs;
+       struct pv *pv = (struct pv *)txq->bounce_buf;
        struct mlx4_sq *sq = &txq->msq;
-       struct rte_mbuf *buf;
        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 srcrb_flags;
-       uint32_t owner_opcode = MLX4_OPCODE_SEND;
        uint32_t byte_count;
-       int wqe_real_size;
-       int nr_txbbs;
-       int rc;
-       struct pv *pv = (struct pv *)txq->bounce_buf;
        int pv_counter = 0;
 
        /* Calculate the needed work queue entry size for this packet. */
-       wqe_real_size = sizeof(struct mlx4_wqe_ctrl_seg) +
-                       pkt->nb_segs * sizeof(struct mlx4_wqe_data_seg);
+       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) {
-               rc = ENOSPC;
-               goto err;
+                               sq->headroom_txbbs) >= sq->txbb_cnt ||
+                       nr_txbbs > MLX4_MAX_WQE_TXBBS) {
+               return -1;
        }
        /* Get the control and data entries of the WQE. */
-       ctrl = (struct mlx4_wqe_ctrl_seg *)mlx4_get_send_wqe(sq, head_idx);
-       dseg = (struct mlx4_wqe_data_seg *)((uintptr_t)ctrl +
-                                           sizeof(struct mlx4_wqe_ctrl_seg));
+       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 (buf = pkt; buf != NULL; buf = buf->next, dseg++) {
-               addr = rte_pktmbuf_mtod(buf, uintptr_t);
+       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 (unlikely(dseg >= (struct mlx4_wqe_data_seg *)sq->eob))
-                       dseg = (struct mlx4_wqe_data_seg *)sq->buf;
+               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 for this memory pool. */
-               lkey = mlx4_txq_mp2mr(txq, mlx4_txq_mb2mp(buf));
-               if (unlikely(lkey == (uint32_t)-1)) {
+               /* 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);
+                                       (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);
-                       rc = EFAULT;
-                       goto err;
+                                       (sq->head & sq->txbb_cnt) ? 0 : 1);
+                       return -1;
                }
-               dseg->lkey = rte_cpu_to_be_32(lkey);
-               if (likely(buf->data_len)) {
-                       byte_count = rte_cpu_to_be_32(buf->data_len);
+#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
@@ -383,6 +502,7 @@ mlx4_post_send(struct txq *txq, struct rte_mbuf *pkt)
                 * 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
@@ -393,6 +513,7 @@ mlx4_post_send(struct txq *txq, struct rte_mbuf *pkt)
                         * data, and end up sending the wrong data.
                         */
                        rte_io_wmb();
+#endif /* RTE_CACHE_LINE_SIZE */
                        dseg->byte_count = byte_count;
                } else {
                        /*
@@ -413,39 +534,7 @@ mlx4_post_send(struct txq *txq, struct rte_mbuf *pkt)
        }
        /* Fill the control parameters for this packet. */
        ctrl->fence_size = (wqe_real_size >> 4) & 0x3f;
-       /*
-        * The caller should prepare "imm" in advance in order to support
-        * VF to VF communication (when the device is a virtual-function
-        * device (VF)).
-        */
-       ctrl->imm = 0;
-       /*
-        * 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);
-       }
-       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_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;
-       return 0;
-err:
-       rte_errno = rc;
-       return -rc;
+       return nr_txbbs;
 }
 
 /**
@@ -467,14 +556,15 @@ 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 elts_comp = 0;
        unsigned int bytes_sent = 0;
        unsigned int i;
        unsigned int max;
-       int err;
+       struct mlx4_sq *sq = &txq->msq;
+       int nr_txbbs;
 
        assert(txq->elts_comp_cd != 0);
-       mlx4_txq_complete(txq);
+       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;
@@ -482,8 +572,6 @@ mlx4_tx_burst(void *dpdk_txq, struct rte_mbuf **pkts, uint16_t pkts_n)
        assert(max <= elts_n);
        /* Always leave one free entry in the ring. */
        --max;
-       if (max == 0)
-               return 0;
        if (max > pkts_n)
                max = pkts_n;
        for (i = 0; (i != max); ++i) {
@@ -492,6 +580,16 @@ mlx4_tx_burst(void *dpdk_txq, struct rte_mbuf **pkts, uint16_t pkts_n)
                        (((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)) {
@@ -510,18 +608,124 @@ mlx4_tx_burst(void *dpdk_txq, struct rte_mbuf **pkts, uint16_t pkts_n)
                        } while (tmp != NULL);
                }
                RTE_MBUF_PREFETCH_TO_FREE(elt_next->buf);
-               /* Post the packet for sending. */
-               err = mlx4_post_send(txq, buf);
-               if (unlikely(err)) {
-                       elt->buf = NULL;
-                       goto stop;
+               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_comp;
                elts_head = elts_head_next;
        }
-stop:
        /* Take a shortcut if nothing must be sent. */
        if (unlikely(i == 0))
                return 0;
@@ -533,14 +737,160 @@ stop:
        /* Ring QP doorbell. */
        rte_write32(txq->msq.doorbell_qpn, txq->msq.db);
        txq->elts_head = elts_head;
-       txq->elts_comp += elts_comp;
+       txq->elts_comp += i;
        return i;
 }
 
 /**
- * DPDK callback for Rx.
+ * 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,
+                  uint32_t l2tun_offload)
+{
+       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 (l2tun_offload && (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.
  *
- * The following function doesn't manage scattered packets.
+ * @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.
@@ -555,112 +905,121 @@ stop:
 uint16_t
 mlx4_rx_burst(void *dpdk_rxq, struct rte_mbuf **pkts, uint16_t pkts_n)
 {
-       struct rxq *rxq = (struct rxq *)dpdk_rxq;
-       struct rxq_elt (*elts)[rxq->elts_n] = rxq->elts;
-       const unsigned int elts_n = rxq->elts_n;
-       unsigned int elts_head = rxq->elts_head;
-       struct ibv_wc wcs[pkts_n];
-       struct ibv_recv_wr *wr_head = NULL;
-       struct ibv_recv_wr **wr_next = &wr_head;
-       struct ibv_recv_wr *wr_bad = NULL;
-       unsigned int i;
-       unsigned int pkts_ret = 0;
-       int ret;
+       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;
 
-       ret = ibv_poll_cq(rxq->cq, pkts_n, wcs);
-       if (unlikely(ret == 0))
-               return 0;
-       if (unlikely(ret < 0)) {
-               DEBUG("rxq=%p, ibv_poll_cq() failed (wc_n=%d)",
-                     (void *)rxq, ret);
-               return 0;
-       }
-       assert(ret <= (int)pkts_n);
-       /* For each work completion. */
-       for (i = 0; i != (unsigned int)ret; ++i) {
-               struct ibv_wc *wc = &wcs[i];
-               struct rxq_elt *elt = &(*elts)[elts_head];
-               struct ibv_recv_wr *wr = &elt->wr;
-               uint32_t len = wc->byte_len;
-               struct rte_mbuf *seg = elt->buf;
-               struct rte_mbuf *rep;
-
-               /* Sanity checks. */
-               assert(wr->sg_list == &elt->sge);
-               assert(wr->num_sge == 1);
-               assert(elts_head < rxq->elts_n);
-               assert(rxq->elts_head < rxq->elts_n);
-               /*
-                * Fetch initial bytes of packet descriptor into a
-                * cacheline while allocating rep.
-                */
-               rte_mbuf_prefetch_part1(seg);
-               rte_mbuf_prefetch_part2(seg);
-               /* Link completed WRs together for repost. */
-               *wr_next = wr;
-               wr_next = &wr->next;
-               if (unlikely(wc->status != IBV_WC_SUCCESS)) {
-                       /* Whatever, just repost the offending WR. */
-                       DEBUG("rxq=%p: bad work completion status (%d): %s",
-                             (void *)rxq, wc->status,
-                             ibv_wc_status_str(wc->status));
-                       /* Increment dropped packets counter. */
-                       ++rxq->stats.idropped;
-                       goto repost;
-               }
+       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)) {
-                       /*
-                        * Unable to allocate a replacement mbuf,
-                        * repost WR.
-                        */
-                       DEBUG("rxq=%p: can't allocate a new mbuf",
-                             (void *)rxq);
-                       /* Increase out of memory counters. */
                        ++rxq->stats.rx_nombuf;
-                       ++rxq->priv->dev->data->rx_mbuf_alloc_failed;
-                       goto repost;
+                       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, rxq->l2tun_offload);
+                       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;
                }
-               /* Reconfigure sge to use rep instead of seg. */
-               elt->sge.addr = (uintptr_t)rep->buf_addr + RTE_PKTMBUF_HEADROOM;
-               assert(elt->sge.lkey == rxq->mr->lkey);
-               elt->buf = rep;
-               /* Update seg information. */
-               seg->data_off = RTE_PKTMBUF_HEADROOM;
-               seg->nb_segs = 1;
-               seg->port = rxq->port_id;
-               seg->next = NULL;
-               seg->pkt_len = len;
+               /* The last segment. */
                seg->data_len = len;
-               seg->packet_type = 0;
-               seg->ol_flags = 0;
+               /* Increment bytes counter. */
+               rxq->stats.ibytes += pkt->pkt_len;
                /* Return packet. */
-               *(pkts++) = seg;
-               ++pkts_ret;
-               /* Increase bytes counter. */
-               rxq->stats.ibytes += len;
-repost:
-               if (++elts_head >= elts_n)
-                       elts_head = 0;
-               continue;
+               *(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))
+       if (unlikely(i == 0 && (rq_ci >> sges_n) == rxq->rq_ci))
                return 0;
-       /* Repost WRs. */
-       *wr_next = NULL;
-       assert(wr_head);
-       ret = ibv_post_wq_recv(rxq->wq, wr_head, &wr_bad);
-       if (unlikely(ret)) {
-               /* Inability to repost WRs is fatal. */
-               DEBUG("%p: recv_burst(): failed (ret=%d)",
-                     (void *)rxq->priv,
-                     ret);
-               abort();
-       }
-       rxq->elts_head = elts_head;
-       /* Increase packets counter. */
-       rxq->stats.ipackets += pkts_ret;
-       return pkts_ret;
+       /* 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;
 }
 
 /**