+ if (unlikely(!pkts_n))
+ return 0;
+ /* Prefetch first packet cacheline. */
+ rte_prefetch0(tx_mlx5_wqe(txq, txq->wqe_ci));
+ rte_prefetch0(tx_mlx5_wqe(txq, txq->wqe_ci + 1));
+ /* Start processing. */
+ txq_complete(txq);
+ max = (elts_n - (elts_head - txq->elts_tail));
+ if (max > elts_n)
+ max -= elts_n;
+ max_wqe = (1u << txq->wqe_n) - (txq->wqe_ci - txq->wqe_pi);
+ if (unlikely(!max_wqe))
+ return 0;
+ do {
+ struct rte_mbuf *buf = *(pkts++);
+ unsigned int elts_head_next;
+ uint32_t length;
+ unsigned int segs_n = buf->nb_segs;
+ uint32_t cs_flags = 0;
+
+ /*
+ * Make sure there is enough room to store this packet and
+ * that one ring entry remains unused.
+ */
+ assert(segs_n);
+ if (max < segs_n + 1)
+ break;
+ /* Do not bother with large packets MPW cannot handle. */
+ if (segs_n > MLX5_MPW_DSEG_MAX)
+ break;
+ max -= segs_n;
+ --pkts_n;
+ /* Should we enable HW CKSUM offload */
+ if (buf->ol_flags &
+ (PKT_TX_IP_CKSUM | PKT_TX_TCP_CKSUM | PKT_TX_UDP_CKSUM))
+ cs_flags = MLX5_ETH_WQE_L3_CSUM | MLX5_ETH_WQE_L4_CSUM;
+ /* Retrieve packet information. */
+ length = PKT_LEN(buf);
+ assert(length);
+ /* Start new session if packet differs. */
+ if ((mpw.state == MLX5_MPW_STATE_OPENED) &&
+ ((mpw.len != length) ||
+ (segs_n != 1) ||
+ (mpw.wqe->eseg.cs_flags != cs_flags)))
+ mlx5_mpw_close(txq, &mpw);
+ if (mpw.state == MLX5_MPW_STATE_CLOSED) {
+ /*
+ * Multi-Packet WQE consumes at most two WQE.
+ * mlx5_mpw_new() expects to be able to use such
+ * resources.
+ */
+ if (unlikely(max_wqe < 2))
+ break;
+ max_wqe -= 2;
+ mlx5_mpw_new(txq, &mpw, length);
+ mpw.wqe->eseg.cs_flags = cs_flags;
+ }
+ /* Multi-segment packets must be alone in their MPW. */
+ assert((segs_n == 1) || (mpw.pkts_n == 0));
+#if defined(MLX5_PMD_SOFT_COUNTERS) || !defined(NDEBUG)
+ length = 0;
+#endif
+ do {
+ volatile struct mlx5_wqe_data_seg *dseg;
+ uintptr_t addr;
+
+ elts_head_next = (elts_head + 1) & (elts_n - 1);
+ assert(buf);
+ (*txq->elts)[elts_head] = buf;
+ dseg = mpw.data.dseg[mpw.pkts_n];
+ addr = rte_pktmbuf_mtod(buf, uintptr_t);
+ *dseg = (struct mlx5_wqe_data_seg){
+ .byte_count = htonl(DATA_LEN(buf)),
+ .lkey = txq_mp2mr(txq, txq_mb2mp(buf)),
+ .addr = htonll(addr),
+ };
+ elts_head = elts_head_next;
+#if defined(MLX5_PMD_SOFT_COUNTERS) || !defined(NDEBUG)
+ length += DATA_LEN(buf);
+#endif
+ buf = buf->next;
+ ++mpw.pkts_n;
+ ++j;
+ } while (--segs_n);
+ assert(length == mpw.len);
+ if (mpw.pkts_n == MLX5_MPW_DSEG_MAX)
+ mlx5_mpw_close(txq, &mpw);
+ elts_head = elts_head_next;
+#ifdef MLX5_PMD_SOFT_COUNTERS
+ /* Increment sent bytes counter. */
+ txq->stats.obytes += length;
+#endif
+ ++i;
+ } while (pkts_n);
+ /* Take a shortcut if nothing must be sent. */
+ if (unlikely(i == 0))
+ return 0;
+ /* Check whether completion threshold has been reached. */
+ /* "j" includes both packets and segments. */
+ comp = txq->elts_comp + j;
+ if (comp >= MLX5_TX_COMP_THRESH) {
+ volatile struct mlx5_wqe *wqe = mpw.wqe;
+
+ /* Request completion on last WQE. */
+ wqe->ctrl[2] = htonl(8);
+ /* Save elts_head in unused "immediate" field of WQE. */
+ wqe->ctrl[3] = elts_head;
+ txq->elts_comp = 0;
+ } else {
+ txq->elts_comp = comp;
+ }
+#ifdef MLX5_PMD_SOFT_COUNTERS
+ /* Increment sent packets counter. */
+ txq->stats.opackets += i;
+#endif
+ /* Ring QP doorbell. */
+ if (mpw.state == MLX5_MPW_STATE_OPENED)
+ mlx5_mpw_close(txq, &mpw);
+ mlx5_tx_dbrec(txq, mpw.wqe);
+ txq->elts_head = elts_head;
+ return i;
+}
+
+/**
+ * Open a MPW inline session.
+ *
+ * @param txq
+ * Pointer to TX queue structure.
+ * @param mpw
+ * Pointer to MPW session structure.
+ * @param length
+ * Packet length.
+ */
+static inline void
+mlx5_mpw_inline_new(struct txq *txq, struct mlx5_mpw *mpw, uint32_t length)
+{
+ uint16_t idx = txq->wqe_ci & ((1 << txq->wqe_n) - 1);
+ struct mlx5_wqe_inl_small *inl;
+
+ mpw->state = MLX5_MPW_INL_STATE_OPENED;
+ mpw->pkts_n = 0;
+ mpw->len = length;
+ mpw->total_len = 0;
+ mpw->wqe = (volatile struct mlx5_wqe *)tx_mlx5_wqe(txq, idx);
+ mpw->wqe->ctrl[0] = htonl((MLX5_OPC_MOD_MPW << 24) |
+ (txq->wqe_ci << 8) |
+ MLX5_OPCODE_TSO);
+ mpw->wqe->ctrl[2] = 0;
+ mpw->wqe->ctrl[3] = 0;
+ mpw->wqe->eseg.mss = htons(length);
+ mpw->wqe->eseg.inline_hdr_sz = 0;
+ mpw->wqe->eseg.cs_flags = 0;
+ mpw->wqe->eseg.rsvd0 = 0;
+ mpw->wqe->eseg.rsvd1 = 0;
+ mpw->wqe->eseg.rsvd2 = 0;
+ inl = (struct mlx5_wqe_inl_small *)
+ (((uintptr_t)mpw->wqe) + 2 * MLX5_WQE_DWORD_SIZE);
+ mpw->data.raw = (uint8_t *)&inl->raw;
+}
+
+/**
+ * Close a MPW inline session.
+ *
+ * @param txq
+ * Pointer to TX queue structure.
+ * @param mpw
+ * Pointer to MPW session structure.
+ */
+static inline void
+mlx5_mpw_inline_close(struct txq *txq, struct mlx5_mpw *mpw)
+{
+ unsigned int size;
+ struct mlx5_wqe_inl_small *inl = (struct mlx5_wqe_inl_small *)
+ (((uintptr_t)mpw->wqe) + (2 * MLX5_WQE_DWORD_SIZE));
+
+ size = MLX5_WQE_SIZE - MLX5_MWQE64_INL_DATA + mpw->total_len;