[v4,7/8] net/mlx5: implement Tx burst template

This patch adds the implementation of tx_burst routine template.
The template supports all Tx offloads and multiple optimized
tx_burst routines can be generated by compiler from this one.

Signed-off-by: Viacheslav Ovsiienko <viacheslavo@mellanox.com>
---
 drivers/net/mlx5/mlx5_rxtx.c | 2958 +++++++++++++++++++++++++++++++++++++++++-
 drivers/net/mlx5/mlx5_rxtx.h |    5 +-
 2 files changed, 2934 insertions(+), 29 deletions(-)

> On Jul 21, 2019, at 7:24 AM, Viacheslav Ovsiienko <viacheslavo@mellanox.com> wrote:
> 
> This patch adds the implementation of tx_burst routine template.
> The template supports all Tx offloads and multiple optimized
> tx_burst routines can be generated by compiler from this one.
> 
> Signed-off-by: Viacheslav Ovsiienko <viacheslavo@mellanox.com>
> ---

Acked-by: Yongseok Koh <yskoh@mellanox.com>

> drivers/net/mlx5/mlx5_rxtx.c | 2958 +++++++++++++++++++++++++++++++++++++++++-
> drivers/net/mlx5/mlx5_rxtx.h |    5 +-
> 2 files changed, 2934 insertions(+), 29 deletions(-)
> 
> diff --git a/drivers/net/mlx5/mlx5_rxtx.c b/drivers/net/mlx5/mlx5_rxtx.c
> index 16be493..35d60f4 100644
> --- a/drivers/net/mlx5/mlx5_rxtx.c
> +++ b/drivers/net/mlx5/mlx5_rxtx.c
> @@ -339,6 +339,109 @@ enum mlx5_txcmp_code {
> }
> 
> /**
> + * Set Software Parser flags and offsets in Ethernet Segment of WQE.
> + * Flags must be preliminary initialized to zero.
> + *
> + * @param loc
> + *   Pointer to burst routine local context.
> + * @param swp_flags
> + *   Pointer to store Software Parser flags
> + * @param olx
> + *   Configured Tx offloads mask. It is fully defined at
> + *   compile time and may be used for optimization.
> + *
> + * @return
> + *   Software Parser offsets packed in dword.
> + *   Software Parser flags are set by pointer.
> + */
> +static __rte_always_inline uint32_t
> +txq_mbuf_to_swp(struct mlx5_txq_local *restrict loc,
> +		uint8_t *swp_flags,
> +		unsigned int olx)
> +{
> +	uint64_t ol, tunnel;
> +	unsigned int idx, off;
> +	uint32_t set;
> +
> +	if (!MLX5_TXOFF_CONFIG(SWP))
> +		return 0;
> +	ol = loc->mbuf->ol_flags;
> +	tunnel = ol & PKT_TX_TUNNEL_MASK;
> +	/*
> +	 * Check whether Software Parser is required.
> +	 * Only customized tunnels may ask for.
> +	 */
> +	if (likely(tunnel != PKT_TX_TUNNEL_UDP && tunnel != PKT_TX_TUNNEL_IP))
> +		return 0;
> +	/*
> +	 * The index should have:
> +	 * bit[0:1] = PKT_TX_L4_MASK
> +	 * bit[4] = PKT_TX_IPV6
> +	 * bit[8] = PKT_TX_OUTER_IPV6
> +	 * bit[9] = PKT_TX_OUTER_UDP
> +	 */
> +	idx = (ol & (PKT_TX_L4_MASK | PKT_TX_IPV6 | PKT_TX_OUTER_IPV6)) >> 52;
> +	idx |= (tunnel == PKT_TX_TUNNEL_UDP) ? (1 << 9) : 0;
> +	*swp_flags = mlx5_swp_types_table[idx];
> +	/*
> +	 * Set offsets for SW parser. Since ConnectX-5, SW parser just
> +	 * complements HW parser. SW parser starts to engage only if HW parser
> +	 * can't reach a header. For the older devices, HW parser will not kick
> +	 * in if any of SWP offsets is set. Therefore, all of the L3 offsets
> +	 * should be set regardless of HW offload.
> +	 */
> +	off = loc->mbuf->outer_l2_len;
> +	if (MLX5_TXOFF_CONFIG(VLAN) && ol & PKT_TX_VLAN_PKT)
> +		off += sizeof(struct rte_vlan_hdr);
> +	set = (off >> 1) << 8; /* Outer L3 offset. */
> +	off += loc->mbuf->outer_l3_len;
> +	if (tunnel == PKT_TX_TUNNEL_UDP)
> +		set |= off >> 1; /* Outer L4 offset. */
> +	if (ol & (PKT_TX_IPV4 | PKT_TX_IPV6)) { /* Inner IP. */
> +		const uint64_t csum = ol & PKT_TX_L4_MASK;
> +			off += loc->mbuf->l2_len;
> +		set |= (off >> 1) << 24; /* Inner L3 offset. */
> +		if (csum == PKT_TX_TCP_CKSUM ||
> +		    csum == PKT_TX_UDP_CKSUM ||
> +		    (MLX5_TXOFF_CONFIG(TSO) && ol & PKT_TX_TCP_SEG)) {
> +			off += loc->mbuf->l3_len;
> +			set |= (off >> 1) << 16; /* Inner L4 offset. */
> +		}
> +	}
> +	set = rte_cpu_to_le_32(set);
> +	return set;
> +}
> +
> +/**
> + * Convert the Checksum offloads to Verbs.
> + *
> + * @param buf
> + *   Pointer to the mbuf.
> + *
> + * @return
> + *   Converted checksum flags.
> + */
> +static __rte_always_inline uint8_t
> +txq_ol_cksum_to_cs(struct rte_mbuf *buf)
> +{
> +	uint32_t idx;
> +	uint8_t is_tunnel = !!(buf->ol_flags & PKT_TX_TUNNEL_MASK);
> +	const uint64_t ol_flags_mask = PKT_TX_TCP_SEG | PKT_TX_L4_MASK |
> +				       PKT_TX_IP_CKSUM | PKT_TX_OUTER_IP_CKSUM;
> +
> +	/*
> +	 * The index should have:
> +	 * bit[0] = PKT_TX_TCP_SEG
> +	 * bit[2:3] = PKT_TX_UDP_CKSUM, PKT_TX_TCP_CKSUM
> +	 * bit[4] = PKT_TX_IP_CKSUM
> +	 * bit[8] = PKT_TX_OUTER_IP_CKSUM
> +	 * bit[9] = tunnel
> +	 */
> +	idx = ((buf->ol_flags & ol_flags_mask) >> 50) | (!!is_tunnel << 9);
> +	return mlx5_cksum_table[idx];
> +}
> +
> +/**
>  * Internal function to compute the number of used descriptors in an RX queue
>  *
>  * @param rxq
> @@ -543,7 +646,7 @@ enum mlx5_txcmp_code {
>  *   The last Tx buffer element to free.
>  */
> uint16_t
> -mlx5_tx_error_cqe_handle(struct mlx5_txq_data *txq,
> +mlx5_tx_error_cqe_handle(struct mlx5_txq_data *restrict txq,
> 			 volatile struct mlx5_err_cqe *err_cqe)
> {
> 	if (err_cqe->syndrome != MLX5_CQE_SYNDROME_WR_FLUSH_ERR) {
> @@ -1563,6 +1666,298 @@ enum mlx5_txcmp_code {
> }
> 
> /**
> + * Free the mbufs from the linear array of pointers.
> + *
> + * @param pkts
> + *   Pointer to array of packets to be free.
> + * @param pkts_n
> + *   Number of packets to be freed.
> + * @param olx
> + *   Configured Tx offloads mask. It is fully defined at
> + *   compile time and may be used for optimization.
> + */
> +static __rte_always_inline void
> +mlx5_tx_free_mbuf(struct rte_mbuf **restrict pkts,
> +		  unsigned int pkts_n,
> +		  unsigned int olx __rte_unused)
> +{
> +	struct rte_mempool *pool = NULL;
> +	struct rte_mbuf **p_free = NULL;
> +	struct rte_mbuf *mbuf;
> +	unsigned int n_free = 0;
> +
> +	/*
> +	 * The implemented algorithm eliminates
> +	 * copying pointers to temporary array
> +	 * for rte_mempool_put_bulk() calls.
> +	 */
> +	assert(pkts);
> +	assert(pkts_n);
> +	for (;;) {
> +		for (;;) {
> +			/*
> +			 * Decrement mbuf reference counter, detach
> +			 * indirect and external buffers if needed.
> +			 */
> +			mbuf = rte_pktmbuf_prefree_seg(*pkts);
> +			if (likely(mbuf != NULL)) {
> +				assert(mbuf == *pkts);
> +				if (likely(n_free != 0)) {
> +					if (unlikely(pool != mbuf->pool))
> +						/* From different pool. */
> +						break;
> +				} else {
> +					/* Start new scan array. */
> +					pool = mbuf->pool;
> +					p_free = pkts;
> +				}
> +				++n_free;
> +				++pkts;
> +				--pkts_n;
> +				if (unlikely(pkts_n == 0)) {
> +					mbuf = NULL;
> +					break;
> +				}
> +			} else {
> +				/*
> +				 * This happens if mbuf is still referenced.
> +				 * We can't put it back to the pool, skip.
> +				 */
> +				++pkts;
> +				--pkts_n;
> +				if (unlikely(n_free != 0))
> +					/* There is some array to free.*/
> +					break;
> +				if (unlikely(pkts_n == 0))
> +					/* Last mbuf, nothing to free. */
> +					return;
> +			}
> +		}
> +		for (;;) {
> +			/*
> +			 * This loop is implemented to avoid multiple
> +			 * inlining of rte_mempool_put_bulk().
> +			 */
> +			assert(pool);
> +			assert(p_free);
> +			assert(n_free);
> +			/*
> +			 * Free the array of pre-freed mbufs
> +			 * belonging to the same memory pool.
> +			 */
> +			rte_mempool_put_bulk(pool, (void *)p_free, n_free);
> +			if (unlikely(mbuf != NULL)) {
> +				/* There is the request to start new scan. */
> +				pool = mbuf->pool;
> +				p_free = pkts++;
> +				n_free = 1;
> +				--pkts_n;
> +				if (likely(pkts_n != 0))
> +					break;
> +				/*
> +				 * This is the last mbuf to be freed.
> +				 * Do one more loop iteration to complete.
> +				 * This is rare case of the last unique mbuf.
> +				 */
> +				mbuf = NULL;
> +				continue;
> +			}
> +			if (likely(pkts_n == 0))
> +				return;
> +			n_free = 0;
> +			break;
> +		}
> +	}
> +}
> +
> +/**
> + * Free the mbuf from the elts ring buffer till new tail.
> + *
> + * @param txq
> + *   Pointer to Tx queue structure.
> + * @param tail
> + *   Index in elts to free up to, becomes new elts tail.
> + * @param olx
> + *   Configured Tx offloads mask. It is fully defined at
> + *   compile time and may be used for optimization.
> + */
> +static __rte_always_inline void
> +mlx5_tx_free_elts(struct mlx5_txq_data *restrict txq,
> +		  uint16_t tail,
> +		  unsigned int olx __rte_unused)
> +{
> +	uint16_t n_elts = tail - txq->elts_tail;
> +
> +	assert(n_elts);
> +	assert(n_elts <= txq->elts_s);
> +	/*
> +	 * Implement a loop to support ring buffer wraparound
> +	 * with single inlining of mlx5_tx_free_mbuf().
> +	 */
> +	do {
> +		unsigned int part;
> +
> +		part = txq->elts_s - (txq->elts_tail & txq->elts_m);
> +		part = RTE_MIN(part, n_elts);
> +		assert(part);
> +		assert(part <= txq->elts_s);
> +		mlx5_tx_free_mbuf(&txq->elts[txq->elts_tail & txq->elts_m],
> +				  part, olx);
> +		txq->elts_tail += part;
> +		n_elts -= part;
> +	} while (n_elts);
> +}
> +
> +/**
> + * Store the mbuf being sent into elts ring buffer.
> + * On Tx completion these mbufs will be freed.
> + *
> + * @param txq
> + *   Pointer to Tx queue structure.
> + * @param pkts
> + *   Pointer to array of packets to be stored.
> + * @param pkts_n
> + *   Number of packets to be stored.
> + * @param olx
> + *   Configured Tx offloads mask. It is fully defined at
> + *   compile time and may be used for optimization.
> + */
> +static __rte_always_inline void
> +mlx5_tx_copy_elts(struct mlx5_txq_data *restrict txq,
> +		  struct rte_mbuf **restrict pkts,
> +		  unsigned int pkts_n,
> +		  unsigned int olx __rte_unused)
> +{
> +	unsigned int part;
> +	struct rte_mbuf **elts = (struct rte_mbuf **)txq->elts;
> +
> +	assert(pkts);
> +	assert(pkts_n);
> +	part = txq->elts_s - (txq->elts_head & txq->elts_m);
> +	assert(part);
> +	assert(part <= txq->elts_s);
> +	/* This code is a good candidate for vectorizing with SIMD. */
> +	rte_memcpy((void *)(elts + (txq->elts_head & txq->elts_m)),
> +		   (void *)pkts,
> +		   RTE_MIN(part, pkts_n) * sizeof(struct rte_mbuf *));
> +	txq->elts_head += pkts_n;
> +	if (unlikely(part < pkts_n))
> +		/* The copy is wrapping around the elts array. */
> +		rte_memcpy((void *)elts, (void *)(pkts + part),
> +			   (pkts_n - part) * sizeof(struct rte_mbuf *));
> +}
> +
> +/**
> + * Manage TX completions. This routine checks the CQ for
> + * arrived CQEs, deduces the last accomplished WQE in SQ,
> + * updates SQ producing index and frees all completed mbufs.
> + *
> + * @param txq
> + *   Pointer to TX queue structure.
> + * @param olx
> + *   Configured Tx offloads mask. It is fully defined at
> + *   compile time and may be used for optimization.
> + *
> + * NOTE: not inlined intentionally, it makes tx_burst
> + * routine smaller, simple and faster - from experiments.
> + */
> +static void
> +mlx5_tx_handle_completion(struct mlx5_txq_data *restrict txq,
> +			  unsigned int olx __rte_unused)
> +{
> +	bool update = false;
> +	int ret;
> +
> +	do {
> +		volatile struct mlx5_wqe_cseg *cseg;
> +		volatile struct mlx5_cqe *cqe;
> +		uint16_t tail;
> +
> +		cqe = &txq->cqes[txq->cq_ci & txq->cqe_m];
> +		ret = check_cqe(cqe, txq->cqe_s, txq->cq_ci);
> +		if (unlikely(ret != MLX5_CQE_STATUS_SW_OWN)) {
> +			if (likely(ret != MLX5_CQE_STATUS_ERR)) {
> +				/* No new CQEs in completion queue. */
> +				assert(ret == MLX5_CQE_STATUS_HW_OWN);
> +				if (likely(update)) {
> +					/* Update the consumer index. */
> +					rte_compiler_barrier();
> +					*txq->cq_db =
> +						rte_cpu_to_be_32(txq->cq_ci);
> +				}
> +				return;
> +			}
> +			/* Some error occurred, try to restart. */
> +			rte_wmb();
> +			tail = mlx5_tx_error_cqe_handle
> +				(txq, (volatile struct mlx5_err_cqe *)cqe);
> +		} else {
> +			/* Normal transmit completion. */
> +			++txq->cq_ci;
> +			rte_cio_rmb();
> +			txq->wqe_pi = rte_be_to_cpu_16(cqe->wqe_counter);
> +			cseg = (volatile struct mlx5_wqe_cseg *)
> +				(txq->wqes + (txq->wqe_pi & txq->wqe_m));
> +			tail = cseg->misc;
> +		}
> +#ifndef NDEBUG
> +		if (txq->cq_pi)
> +			--txq->cq_pi;
> +#endif
> +		if (likely(tail != txq->elts_tail)) {
> +			/* Free data buffers from elts. */
> +			mlx5_tx_free_elts(txq, tail, olx);
> +			assert(tail == txq->elts_tail);
> +		}
> +		update = true;
> +	} while (true);
> +}
> +
> +/**
> + * Check if the completion request flag should be set in the last WQE.
> + * Both pushed mbufs and WQEs are monitored and the completion request
> + * flag is set if any of thresholds is reached.
> + *
> + * @param txq
> + *   Pointer to TX queue structure.
> + * @param n_mbuf
> + *   Number of mbuf not stored yet in elts array.
> + * @param loc
> + *   Pointer to burst routine local context.
> + * @param olx
> + *   Configured Tx offloads mask. It is fully defined at
> + *   compile time and may be used for optimization.
> + */
> +static __rte_always_inline void
> +mlx5_tx_request_completion(struct mlx5_txq_data *restrict txq,
> +			   unsigned int n_mbuf,
> +			   struct mlx5_txq_local *restrict loc,
> +			   unsigned int olx __rte_unused)
> +{
> +	uint16_t head = txq->elts_head + n_mbuf;
> +
> +	if ((uint16_t)(head - txq->elts_comp) >= MLX5_TX_COMP_THRESH ||
> +	    (uint16_t)(txq->wqe_ci - txq->wqe_comp) >= txq->wqe_thres) {
> +		volatile struct mlx5_wqe *last = loc->wqe_last;
> +
> +		txq->elts_comp = head;
> +		txq->wqe_comp = txq->wqe_ci;
> +		/* Request unconditional completion on last WQE. */
> +		last->cseg.flags = RTE_BE32(MLX5_COMP_ALWAYS <<
> +					    MLX5_COMP_MODE_OFFSET);
> +		/* Save elts_head in unused "immediate" field of WQE. */
> +		last->cseg.misc = head;
> +		/*
> +		 * A CQE slot must always be available. Count the
> +		 * issued CEQ "always" request instead of production
> +		 * index due to here can be CQE with errors and
> +		 * difference with ci may become inconsistent.
> +		 */
> +		assert(txq->cqe_s > ++txq->cq_pi);
> +	}
> +}
> +
> +/**
>  * DPDK callback to check the status of a tx descriptor.
>  *
>  * @param tx_queue
> @@ -1576,42 +1971,2551 @@ enum mlx5_txcmp_code {
> int
> mlx5_tx_descriptor_status(void *tx_queue, uint16_t offset)
> {
> -	(void)tx_queue;
> -	(void)offset;
> -	return RTE_ETH_TX_DESC_FULL;
> +	struct mlx5_txq_data *restrict txq = tx_queue;
> +	uint16_t used;
> +
> +	mlx5_tx_handle_completion(txq, 0);
> +	used = txq->elts_head - txq->elts_tail;
> +	if (offset < used)
> +		return RTE_ETH_TX_DESC_FULL;
> +	return RTE_ETH_TX_DESC_DONE;
> }
> 
> /**
> - * DPDK Tx callback template. This is configured template
> - * used to generate routines optimized for specified offload setup.
> - * One of this generated functions is chosen at SQ configuration
> - * time.
> + * Build the Control Segment with specified opcode:
> + * - MLX5_OPCODE_SEND
> + * - MLX5_OPCODE_ENHANCED_MPSW
> + * - MLX5_OPCODE_TSO
>  *
>  * @param txq
> - *   Generic pointer to TX queue structure.
> - * @param[in] pkts
> - *   Packets to transmit.
> - * @param pkts_n
> - *   Number of packets in array.
> + *   Pointer to TX queue structure.
> + * @param loc
> + *   Pointer to burst routine local context.
> + * @param wqe
> + *   Pointer to WQE to fill with built Control Segment.
> + * @param ds
> + *   Supposed length of WQE in segments.
> + * @param opcode
> + *   SQ WQE opcode to put into Control Segment.
>  * @param olx
> - *   Configured offloads mask, presents the bits of MLX5_TXOFF_CONFIG_xxx
> - *   values. Should be static to take compile time static configuration
> - *   advantages.
> + *   Configured Tx offloads mask. It is fully defined at
> + *   compile time and may be used for optimization.
> + */
> +static __rte_always_inline void
> +mlx5_tx_cseg_init(struct mlx5_txq_data *restrict txq,
> +		  struct mlx5_txq_local *restrict loc __rte_unused,
> +		  struct mlx5_wqe *restrict wqe,
> +		  unsigned int ds,
> +		  unsigned int opcode,
> +		  unsigned int olx __rte_unused)
> +{
> +	struct mlx5_wqe_cseg *restrict cs = &wqe->cseg;
> +
> +	cs->opcode = rte_cpu_to_be_32((txq->wqe_ci << 8) | opcode);
> +	cs->sq_ds = rte_cpu_to_be_32(txq->qp_num_8s | ds);
> +	cs->flags = RTE_BE32(MLX5_COMP_ONLY_FIRST_ERR <<
> +			     MLX5_COMP_MODE_OFFSET);
> +	cs->misc = RTE_BE32(0);
> +}
> +
> +/**
> + * Build the Ethernet Segment without inlined data.
> + * Supports Software Parser, Checksums and VLAN
> + * insertion Tx offload features.
> + *
> + * @param txq
> + *   Pointer to TX queue structure.
> + * @param loc
> + *   Pointer to burst routine local context.
> + * @param wqe
> + *   Pointer to WQE to fill with built Ethernet Segment.
> + * @param olx
> + *   Configured Tx offloads mask. It is fully defined at
> + *   compile time and may be used for optimization.
> + */
> +static __rte_always_inline void
> +mlx5_tx_eseg_none(struct mlx5_txq_data *restrict txq __rte_unused,
> +		  struct mlx5_txq_local *restrict loc,
> +		  struct mlx5_wqe *restrict wqe,
> +		  unsigned int olx)
> +{
> +	struct mlx5_wqe_eseg *restrict es = &wqe->eseg;
> +	uint32_t csum;
> +
> +	/*
> +	 * Calculate and set check sum flags first, dword field
> +	 * in segment may be shared with Software Parser flags.
> +	 */
> +	csum = MLX5_TXOFF_CONFIG(CSUM) ? txq_ol_cksum_to_cs(loc->mbuf) : 0;
> +	es->flags = rte_cpu_to_le_32(csum);
> +	/*
> +	 * Calculate and set Software Parser offsets and flags.
> +	 * These flags a set for custom UDP and IP tunnel packets.
> +	 */
> +	es->swp_offs = txq_mbuf_to_swp(loc, &es->swp_flags, olx);
> +	/* Fill metadata field if needed. */
> +	es->metadata = MLX5_TXOFF_CONFIG(METADATA) ?
> +		       loc->mbuf->ol_flags & PKT_TX_METADATA ?
> +		       loc->mbuf->tx_metadata : 0 : 0;
> +	/* Engage VLAN tag insertion feature if requested. */
> +	if (MLX5_TXOFF_CONFIG(VLAN) &&
> +	    loc->mbuf->ol_flags & PKT_TX_VLAN_PKT) {
> +		/*
> +		 * We should get here only if device support
> +		 * this feature correctly.
> +		 */
> +		assert(txq->vlan_en);
> +		es->inline_hdr = rte_cpu_to_be_32(MLX5_ETH_WQE_VLAN_INSERT |
> +						  loc->mbuf->vlan_tci);
> +	} else {
> +		es->inline_hdr = RTE_BE32(0);
> +	}
> +}
> +
> +/**
> + * Build the Ethernet Segment with minimal inlined data
> + * of MLX5_ESEG_MIN_INLINE_SIZE bytes length. This is
> + * used to fill the gap in single WQEBB WQEs.
> + * Supports Software Parser, Checksums and VLAN
> + * insertion Tx offload features.
> + *
> + * @param txq
> + *   Pointer to TX queue structure.
> + * @param loc
> + *   Pointer to burst routine local context.
> + * @param wqe
> + *   Pointer to WQE to fill with built Ethernet Segment.
> + * @param vlan
> + *   Length of VLAN tag insertion if any.
> + * @param olx
> + *   Configured Tx offloads mask. It is fully defined at
> + *   compile time and may be used for optimization.
> + */
> +static __rte_always_inline void
> +mlx5_tx_eseg_dmin(struct mlx5_txq_data *restrict txq __rte_unused,
> +		  struct mlx5_txq_local *restrict loc,
> +		  struct mlx5_wqe *restrict wqe,
> +		  unsigned int vlan,
> +		  unsigned int olx)
> +{
> +	struct mlx5_wqe_eseg *restrict es = &wqe->eseg;
> +	uint32_t csum;
> +	uint8_t *psrc, *pdst;
> +
> +	/*
> +	 * Calculate and set check sum flags first, dword field
> +	 * in segment may be shared with Software Parser flags.
> +	 */
> +	csum = MLX5_TXOFF_CONFIG(CSUM) ? txq_ol_cksum_to_cs(loc->mbuf) : 0;
> +	es->flags = rte_cpu_to_le_32(csum);
> +	/*
> +	 * Calculate and set Software Parser offsets and flags.
> +	 * These flags a set for custom UDP and IP tunnel packets.
> +	 */
> +	es->swp_offs = txq_mbuf_to_swp(loc, &es->swp_flags, olx);
> +	/* Fill metadata field if needed. */
> +	es->metadata = MLX5_TXOFF_CONFIG(METADATA) ?
> +		       loc->mbuf->ol_flags & PKT_TX_METADATA ?
> +		       loc->mbuf->tx_metadata : 0 : 0;
> +	static_assert(MLX5_ESEG_MIN_INLINE_SIZE ==
> +				(sizeof(uint16_t) +
> +				 sizeof(rte_v128u32_t)),
> +		      "invalid Ethernet Segment data size");
> +	static_assert(MLX5_ESEG_MIN_INLINE_SIZE ==
> +				(sizeof(uint16_t) +
> +				 sizeof(struct rte_vlan_hdr) +
> +				 2 * RTE_ETHER_ADDR_LEN),
> +		      "invalid Ethernet Segment data size");
> +	psrc = rte_pktmbuf_mtod(loc->mbuf, uint8_t *);
> +	es->inline_hdr_sz = RTE_BE16(MLX5_ESEG_MIN_INLINE_SIZE);
> +	es->inline_data = *(unaligned_uint16_t *)psrc;
> +	psrc +=	sizeof(uint16_t);
> +	pdst = (uint8_t *)(es + 1);
> +	if (MLX5_TXOFF_CONFIG(VLAN) && vlan) {
> +		/* Implement VLAN tag insertion as part inline data. */
> +		memcpy(pdst, psrc, 2 * RTE_ETHER_ADDR_LEN - sizeof(uint16_t));
> +		pdst += 2 * RTE_ETHER_ADDR_LEN - sizeof(uint16_t);
> +		psrc +=	2 * RTE_ETHER_ADDR_LEN - sizeof(uint16_t);
> +		/* Insert VLAN ethertype + VLAN tag. */
> +		*(unaligned_uint32_t *)pdst = rte_cpu_to_be_32
> +						((RTE_ETHER_TYPE_VLAN << 16) |
> +						 loc->mbuf->vlan_tci);
> +		pdst += sizeof(struct rte_vlan_hdr);
> +		/* Copy the rest two bytes from packet data. */
> +		assert(pdst == RTE_PTR_ALIGN(pdst, sizeof(uint16_t)));
> +		*(uint16_t *)pdst = *(unaligned_uint16_t *)psrc;
> +	} else {
> +		/* Fill the gap in the title WQEBB with inline data. */
> +		rte_mov16(pdst, psrc);
> +	}
> +}
> +
> +/**
> + * Build the Ethernet Segment with entire packet
> + * data inlining. Checks the boundary of WQEBB and
> + * ring buffer wrapping, supports Software Parser,
> + * Checksums and VLAN insertion Tx offload features.
> + *
> + * @param txq
> + *   Pointer to TX queue structure.
> + * @param loc
> + *   Pointer to burst routine local context.
> + * @param wqe
> + *   Pointer to WQE to fill with built Ethernet Segment.
> + * @param vlan
> + *   Length of VLAN tag insertion if any.
> + * @param inlen
> + *   Length of data to inline (VLAN included, if any).
> + * @param tso
> + *   TSO flag, set mss field from the packet.
> + * @param olx
> + *   Configured Tx offloads mask. It is fully defined at
> + *   compile time and may be used for optimization.
>  *
>  * @return
> - *   Number of packets successfully transmitted (<= pkts_n).
> + *   Pointer to the next Data Segment (aligned and wrapped around).
>  */
> -static __rte_always_inline uint16_t
> -mlx5_tx_burst_tmpl(struct mlx5_txq_data *restrict txq,
> -		   struct rte_mbuf **restrict pkts,
> -		   uint16_t pkts_n,
> -		   unsigned int olx)
> +static __rte_always_inline struct mlx5_wqe_dseg *
> +mlx5_tx_eseg_data(struct mlx5_txq_data *restrict txq,
> +		  struct mlx5_txq_local *restrict loc,
> +		  struct mlx5_wqe *restrict wqe,
> +		  unsigned int vlan,
> +		  unsigned int inlen,
> +		  unsigned int tso,
> +		  unsigned int olx)
> {
> -	(void)txq;
> -	(void)pkts;
> -	(void)pkts_n;
> -	(void)olx;
> -	return 0;
> +	struct mlx5_wqe_eseg *restrict es = &wqe->eseg;
> +	uint32_t csum;
> +	uint8_t *psrc, *pdst;
> +	unsigned int part;
> +
> +	/*
> +	 * Calculate and set check sum flags first, dword field
> +	 * in segment may be shared with Software Parser flags.
> +	 */
> +	csum = MLX5_TXOFF_CONFIG(CSUM) ? txq_ol_cksum_to_cs(loc->mbuf) : 0;
> +	if (tso) {
> +		csum <<= 24;
> +		csum |= loc->mbuf->tso_segsz;
> +		es->flags = rte_cpu_to_be_32(csum);
> +	} else {
> +		es->flags = rte_cpu_to_le_32(csum);
> +	}
> +	/*
> +	 * Calculate and set Software Parser offsets and flags.
> +	 * These flags a set for custom UDP and IP tunnel packets.
> +	 */
> +	es->swp_offs = txq_mbuf_to_swp(loc, &es->swp_flags, olx);
> +	/* Fill metadata field if needed. */
> +	es->metadata = MLX5_TXOFF_CONFIG(METADATA) ?
> +		       loc->mbuf->ol_flags & PKT_TX_METADATA ?
> +		       loc->mbuf->tx_metadata : 0 : 0;
> +	static_assert(MLX5_ESEG_MIN_INLINE_SIZE ==
> +				(sizeof(uint16_t) +
> +				 sizeof(rte_v128u32_t)),
> +		      "invalid Ethernet Segment data size");
> +	static_assert(MLX5_ESEG_MIN_INLINE_SIZE ==
> +				(sizeof(uint16_t) +
> +				 sizeof(struct rte_vlan_hdr) +
> +				 2 * RTE_ETHER_ADDR_LEN),
> +		      "invalid Ethernet Segment data size");
> +	psrc = rte_pktmbuf_mtod(loc->mbuf, uint8_t *);
> +	es->inline_hdr_sz = rte_cpu_to_be_16(inlen);
> +	es->inline_data = *(unaligned_uint16_t *)psrc;
> +	psrc +=	sizeof(uint16_t);
> +	pdst = (uint8_t *)(es + 1);
> +	if (MLX5_TXOFF_CONFIG(VLAN) && vlan) {
> +		/* Implement VLAN tag insertion as part inline data. */
> +		memcpy(pdst, psrc, 2 * RTE_ETHER_ADDR_LEN - sizeof(uint16_t));
> +		pdst += 2 * RTE_ETHER_ADDR_LEN - sizeof(uint16_t);
> +		psrc +=	2 * RTE_ETHER_ADDR_LEN - sizeof(uint16_t);
> +		/* Insert VLAN ethertype + VLAN tag. */
> +		*(unaligned_uint32_t *)pdst = rte_cpu_to_be_32
> +						((RTE_ETHER_TYPE_VLAN << 16) |
> +						 loc->mbuf->vlan_tci);
> +		pdst += sizeof(struct rte_vlan_hdr);
> +		/* Copy the rest two bytes from packet data. */
> +		assert(pdst == RTE_PTR_ALIGN(pdst, sizeof(uint16_t)));
> +		*(uint16_t *)pdst = *(unaligned_uint16_t *)psrc;
> +		psrc += sizeof(uint16_t);
> +	} else {
> +		/* Fill the gap in the title WQEBB with inline data. */
> +		rte_mov16(pdst, psrc);
> +		psrc += sizeof(rte_v128u32_t);
> +	}
> +	pdst = (uint8_t *)(es + 2);
> +	assert(inlen >= MLX5_ESEG_MIN_INLINE_SIZE);
> +	assert(pdst < (uint8_t *)txq->wqes_end);
> +	inlen -= MLX5_ESEG_MIN_INLINE_SIZE;
> +	if (!inlen) {
> +		assert(pdst == RTE_PTR_ALIGN(pdst, MLX5_WSEG_SIZE));
> +		return (struct mlx5_wqe_dseg *)pdst;
> +	}
> +	/*
> +	 * The WQEBB space availability is checked by caller.
> +	 * Here we should be aware of WQE ring buffer wraparound only.
> +	 */
> +	part = (uint8_t *)txq->wqes_end - pdst;
> +	part = RTE_MIN(part, inlen);
> +	do {
> +		rte_memcpy(pdst, psrc, part);
> +		inlen -= part;
> +		if (likely(!inlen)) {
> +			/*
> +			 * If return value is not used by the caller
> +			 * the code below will be optimized out.
> +			 */
> +			pdst += part;
> +			pdst = RTE_PTR_ALIGN(pdst, MLX5_WSEG_SIZE);
> +			if (unlikely(pdst >= (uint8_t *)txq->wqes_end))
> +				pdst = (uint8_t *)txq->wqes;
> +			return (struct mlx5_wqe_dseg *)pdst;
> +		}
> +		pdst = (uint8_t *)txq->wqes;
> +		psrc += part;
> +		part = inlen;
> +	} while (true);
> +}
> +
> +/**
> + * Copy data from chain of mbuf to the specified linear buffer.
> + * Checksums and VLAN insertion Tx offload features. If data
> + * from some mbuf copied completely this mbuf is freed. Local
> + * structure is used to keep the byte stream state.
> + *
> + * @param pdst
> + *   Pointer to the destination linear buffer.
> + * @param loc
> + *   Pointer to burst routine local context.
> + * @param len
> + *   Length of data to be copied.
> + * @param olx
> + *   Configured Tx offloads mask. It is fully defined at
> + *   compile time and may be used for optimization.
> + */
> +static __rte_always_inline void
> +mlx5_tx_mseg_memcpy(uint8_t *pdst,
> +		    struct mlx5_txq_local *restrict loc,
> +		    unsigned int len,
> +		    unsigned int olx __rte_unused)
> +{
> +	struct rte_mbuf *mbuf;
> +	unsigned int part, dlen;
> +	uint8_t *psrc;
> +
> +	assert(len);
> +	do {
> +		/* Allow zero length packets, must check first. */
> +		dlen = rte_pktmbuf_data_len(loc->mbuf);
> +		if (dlen <= loc->mbuf_off) {
> +			/* Exhausted packet, just free. */
> +			mbuf = loc->mbuf;
> +			loc->mbuf = mbuf->next;
> +			rte_pktmbuf_free_seg(mbuf);
> +			loc->mbuf_off = 0;
> +			assert(loc->mbuf_nseg > 1);
> +			assert(loc->mbuf);
> +			--loc->mbuf_nseg;
> +			continue;
> +		}
> +		dlen -= loc->mbuf_off;
> +		psrc = rte_pktmbuf_mtod_offset(loc->mbuf, uint8_t *,
> +					       loc->mbuf_off);
> +		part = RTE_MIN(len, dlen);
> +		rte_memcpy(pdst, psrc, part);
> +		loc->mbuf_off += part;
> +		len -= part;
> +		if (!len) {
> +			if (loc->mbuf_off >= rte_pktmbuf_data_len(loc->mbuf)) {
> +				loc->mbuf_off = 0;
> +				/* Exhausted packet, just free. */
> +				mbuf = loc->mbuf;
> +				loc->mbuf = mbuf->next;
> +				rte_pktmbuf_free_seg(mbuf);
> +				loc->mbuf_off = 0;
> +				assert(loc->mbuf_nseg >= 1);
> +				--loc->mbuf_nseg;
> +			}
> +			return;
> +		}
> +		pdst += part;
> +	} while (true);
> +}
> +
> +/**
> + * Build the Ethernet Segment with inlined data from
> + * multi-segment packet. Checks the boundary of WQEBB
> + * and ring buffer wrapping, supports Software Parser,
> + * Checksums and VLAN insertion Tx offload features.
> + *
> + * @param txq
> + *   Pointer to TX queue structure.
> + * @param loc
> + *   Pointer to burst routine local context.
> + * @param wqe
> + *   Pointer to WQE to fill with built Ethernet Segment.
> + * @param vlan
> + *   Length of VLAN tag insertion if any.
> + * @param inlen
> + *   Length of data to inline (VLAN included, if any).
> + * @param tso
> + *   TSO flag, set mss field from the packet.
> + * @param olx
> + *   Configured Tx offloads mask. It is fully defined at
> + *   compile time and may be used for optimization.
> + *
> + * @return
> + *   Pointer to the next Data Segment (aligned and
> + *   possible NOT wrapped around - caller should do
> + *   wrapping check on its own).
> + */
> +static __rte_always_inline struct mlx5_wqe_dseg *
> +mlx5_tx_eseg_mdat(struct mlx5_txq_data *restrict txq,
> +		  struct mlx5_txq_local *restrict loc,
> +		  struct mlx5_wqe *restrict wqe,
> +		  unsigned int vlan,
> +		  unsigned int inlen,
> +		  unsigned int tso,
> +		  unsigned int olx)
> +{
> +	struct mlx5_wqe_eseg *restrict es = &wqe->eseg;
> +	uint32_t csum;
> +	uint8_t *pdst;
> +	unsigned int part;
> +
> +	/*
> +	 * Calculate and set check sum flags first, uint32_t field
> +	 * in segment may be shared with Software Parser flags.
> +	 */
> +	csum = MLX5_TXOFF_CONFIG(CSUM) ? txq_ol_cksum_to_cs(loc->mbuf) : 0;
> +	if (tso) {
> +		csum <<= 24;
> +		csum |= loc->mbuf->tso_segsz;
> +		es->flags = rte_cpu_to_be_32(csum);
> +	} else {
> +		es->flags = rte_cpu_to_le_32(csum);
> +	}
> +	/*
> +	 * Calculate and set Software Parser offsets and flags.
> +	 * These flags a set for custom UDP and IP tunnel packets.
> +	 */
> +	es->swp_offs = txq_mbuf_to_swp(loc, &es->swp_flags, olx);
> +	/* Fill metadata field if needed. */
> +	es->metadata = MLX5_TXOFF_CONFIG(METADATA) ?
> +		       loc->mbuf->ol_flags & PKT_TX_METADATA ?
> +		       loc->mbuf->tx_metadata : 0 : 0;
> +	static_assert(MLX5_ESEG_MIN_INLINE_SIZE ==
> +				(sizeof(uint16_t) +
> +				 sizeof(rte_v128u32_t)),
> +		      "invalid Ethernet Segment data size");
> +	static_assert(MLX5_ESEG_MIN_INLINE_SIZE ==
> +				(sizeof(uint16_t) +
> +				 sizeof(struct rte_vlan_hdr) +
> +				 2 * RTE_ETHER_ADDR_LEN),
> +		      "invalid Ethernet Segment data size");
> +	assert(inlen > MLX5_ESEG_MIN_INLINE_SIZE);
> +	es->inline_hdr_sz = rte_cpu_to_be_16(inlen);
> +	pdst = (uint8_t *)&es->inline_data;
> +	if (MLX5_TXOFF_CONFIG(VLAN) && vlan) {
> +		/* Implement VLAN tag insertion as part inline data. */
> +		mlx5_tx_mseg_memcpy(pdst, loc, 2 * RTE_ETHER_ADDR_LEN, olx);
> +		pdst += 2 * RTE_ETHER_ADDR_LEN;
> +		*(unaligned_uint32_t *)pdst = rte_cpu_to_be_32
> +						((RTE_ETHER_TYPE_VLAN << 16) |
> +						 loc->mbuf->vlan_tci);
> +		pdst += sizeof(struct rte_vlan_hdr);
> +		inlen -= 2 * RTE_ETHER_ADDR_LEN + sizeof(struct rte_vlan_hdr);
> +	}
> +	assert(pdst < (uint8_t *)txq->wqes_end);
> +	/*
> +	 * The WQEBB space availability is checked by caller.
> +	 * Here we should be aware of WQE ring buffer wraparound only.
> +	 */
> +	part = (uint8_t *)txq->wqes_end - pdst;
> +	part = RTE_MIN(part, inlen);
> +	assert(part);
> +	do {
> +		mlx5_tx_mseg_memcpy(pdst, loc, part, olx);
> +		inlen -= part;
> +		if (likely(!inlen)) {
> +			pdst += part;
> +			pdst = RTE_PTR_ALIGN(pdst, MLX5_WSEG_SIZE);
> +			return (struct mlx5_wqe_dseg *)pdst;
> +		}
> +		pdst = (uint8_t *)txq->wqes;
> +		part = inlen;
> +	} while (true);
> +}
> +
> +/**
> + * Build the Data Segment of pointer type.
> + *
> + * @param txq
> + *   Pointer to TX queue structure.
> + * @param loc
> + *   Pointer to burst routine local context.
> + * @param dseg
> + *   Pointer to WQE to fill with built Data Segment.
> + * @param buf
> + *   Data buffer to point.
> + * @param len
> + *   Data buffer length.
> + * @param olx
> + *   Configured Tx offloads mask. It is fully defined at
> + *   compile time and may be used for optimization.
> + */
> +static __rte_always_inline void
> +mlx5_tx_dseg_ptr(struct mlx5_txq_data *restrict txq,
> +		 struct mlx5_txq_local *restrict loc,
> +		 struct mlx5_wqe_dseg *restrict dseg,
> +		 uint8_t *buf,
> +		 unsigned int len,
> +		 unsigned int olx __rte_unused)
> +
> +{
> +	assert(len);
> +	dseg->bcount = rte_cpu_to_be_32(len);
> +	dseg->lkey = mlx5_tx_mb2mr(txq, loc->mbuf);
> +	dseg->pbuf = rte_cpu_to_be_64((uintptr_t)buf);
> +}
> +
> +/**
> + * Build the Data Segment of pointer type or inline
> + * if data length is less than buffer in minimal
> + * Data Segment size.
> + *
> + * @param txq
> + *   Pointer to TX queue structure.
> + * @param loc
> + *   Pointer to burst routine local context.
> + * @param dseg
> + *   Pointer to WQE to fill with built Data Segment.
> + * @param buf
> + *   Data buffer to point.
> + * @param len
> + *   Data buffer length.
> + * @param olx
> + *   Configured Tx offloads mask. It is fully defined at
> + *   compile time and may be used for optimization.
> + */
> +static __rte_always_inline void
> +mlx5_tx_dseg_iptr(struct mlx5_txq_data *restrict txq,
> +		  struct mlx5_txq_local *restrict loc,
> +		  struct mlx5_wqe_dseg *restrict dseg,
> +		  uint8_t *buf,
> +		  unsigned int len,
> +		  unsigned int olx __rte_unused)
> +
> +{
> +	uintptr_t dst, src;
> +
> +	assert(len);
> +	if (len > MLX5_DSEG_MIN_INLINE_SIZE) {
> +		dseg->bcount = rte_cpu_to_be_32(len);
> +		dseg->lkey = mlx5_tx_mb2mr(txq, loc->mbuf);
> +		dseg->pbuf = rte_cpu_to_be_64((uintptr_t)buf);
> +
> +		return;
> +	}
> +	dseg->bcount = rte_cpu_to_be_32(len | MLX5_ETH_WQE_DATA_INLINE);
> +	/* Unrolled implementation of generic rte_memcpy. */
> +	dst = (uintptr_t)&dseg->inline_data[0];
> +	src = (uintptr_t)buf;
> +#ifdef RTE_ARCH_STRICT_ALIGN
> +	memcpy(dst, src, len);
> +#else
> +	if (len & 0x08) {
> +		*(uint64_t *)dst = *(uint64_t *)src;
> +		dst += sizeof(uint64_t);
> +		src += sizeof(uint64_t);
> +	}
> +	if (len & 0x04) {
> +		*(uint32_t *)dst = *(uint32_t *)src;
> +		dst += sizeof(uint32_t);
> +		src += sizeof(uint32_t);
> +	}
> +	if (len & 0x02) {
> +		*(uint16_t *)dst = *(uint16_t *)src;
> +		dst += sizeof(uint16_t);
> +		src += sizeof(uint16_t);
> +	}
> +	if (len & 0x01)
> +		*(uint8_t *)dst = *(uint8_t *)src;
> +#endif
> +}
> +
> +/**
> + * Build the Data Segment of inlined data from single
> + * segment packet, no VLAN insertion.
> + *
> + * @param txq
> + *   Pointer to TX queue structure.
> + * @param loc
> + *   Pointer to burst routine local context.
> + * @param dseg
> + *   Pointer to WQE to fill with built Data Segment.
> + * @param buf
> + *   Data buffer to point.
> + * @param len
> + *   Data buffer length.
> + * @param olx
> + *   Configured Tx offloads mask. It is fully defined at
> + *   compile time and may be used for optimization.
> + *
> + * @return
> + *   Pointer to the next Data Segment after inlined data.
> + *   Ring buffer wraparound check is needed. We do not
> + *   do it here because it may not be needed for the
> + *   last packet in the eMPW session.
> + */
> +static __rte_always_inline struct mlx5_wqe_dseg *
> +mlx5_tx_dseg_empw(struct mlx5_txq_data *restrict txq,
> +		  struct mlx5_txq_local *restrict loc __rte_unused,
> +		  struct mlx5_wqe_dseg *restrict dseg,
> +		  uint8_t *buf,
> +		  unsigned int len,
> +		  unsigned int olx __rte_unused)
> +{
> +	unsigned int part;
> +	uint8_t *pdst;
> +
> +	dseg->bcount = rte_cpu_to_be_32(len | MLX5_ETH_WQE_DATA_INLINE);
> +	pdst = &dseg->inline_data[0];
> +	/*
> +	 * The WQEBB space availability is checked by caller.
> +	 * Here we should be aware of WQE ring buffer wraparound only.
> +	 */
> +	part = (uint8_t *)txq->wqes_end - pdst;
> +	part = RTE_MIN(part, len);
> +	do {
> +		rte_memcpy(pdst, buf, part);
> +		len -= part;
> +		if (likely(!len)) {
> +			pdst += part;
> +			pdst = RTE_PTR_ALIGN(pdst, MLX5_WSEG_SIZE);
> +			/* Note: no final wraparound check here. */
> +			return (struct mlx5_wqe_dseg *)pdst;
> +		}
> +		pdst = (uint8_t *)txq->wqes;
> +		buf += part;
> +		part = len;
> +	} while (true);
> +}
> +
> +/**
> + * Build the Data Segment of inlined data from single
> + * segment packet with VLAN insertion.
> + *
> + * @param txq
> + *   Pointer to TX queue structure.
> + * @param loc
> + *   Pointer to burst routine local context.
> + * @param dseg
> + *   Pointer to the dseg fill with built Data Segment.
> + * @param buf
> + *   Data buffer to point.
> + * @param len
> + *   Data buffer length.
> + * @param olx
> + *   Configured Tx offloads mask. It is fully defined at
> + *   compile time and may be used for optimization.
> + *
> + * @return
> + *   Pointer to the next Data Segment after inlined data.
> + *   Ring buffer wraparound check is needed.
> + */
> +static __rte_always_inline struct mlx5_wqe_dseg *
> +mlx5_tx_dseg_vlan(struct mlx5_txq_data *restrict txq,
> +		  struct mlx5_txq_local *restrict loc __rte_unused,
> +		  struct mlx5_wqe_dseg *restrict dseg,
> +		  uint8_t *buf,
> +		  unsigned int len,
> +		  unsigned int olx __rte_unused)
> +
> +{
> +	unsigned int part;
> +	uint8_t *pdst;
> +
> +	assert(len > MLX5_ESEG_MIN_INLINE_SIZE);
> +	static_assert(MLX5_DSEG_MIN_INLINE_SIZE ==
> +				 (2 * RTE_ETHER_ADDR_LEN),
> +		      "invalid Data Segment data size");
> +	dseg->bcount = rte_cpu_to_be_32((len + sizeof(struct rte_vlan_hdr)) |
> +					MLX5_ETH_WQE_DATA_INLINE);
> +	pdst = &dseg->inline_data[0];
> +	memcpy(pdst, buf, MLX5_DSEG_MIN_INLINE_SIZE);
> +	buf += MLX5_DSEG_MIN_INLINE_SIZE;
> +	pdst += MLX5_DSEG_MIN_INLINE_SIZE;
> +	/* Insert VLAN ethertype + VLAN tag. Pointer is aligned. */
> +	assert(pdst == RTE_PTR_ALIGN(pdst, MLX5_WSEG_SIZE));
> +	*(uint32_t *)pdst = rte_cpu_to_be_32((RTE_ETHER_TYPE_VLAN << 16) |
> +					      loc->mbuf->vlan_tci);
> +	pdst += sizeof(struct rte_vlan_hdr);
> +	if (unlikely(pdst >= (uint8_t *)txq->wqes_end))
> +		pdst = (uint8_t *)txq->wqes;
> +	/*
> +	 * The WQEBB space availability is checked by caller.
> +	 * Here we should be aware of WQE ring buffer wraparound only.
> +	 */
> +	part = (uint8_t *)txq->wqes_end - pdst;
> +	part = RTE_MIN(part, len);
> +	do {
> +		rte_memcpy(pdst, buf, part);
> +		len -= part;
> +		if (likely(!len)) {
> +			pdst += part;
> +			pdst = RTE_PTR_ALIGN(pdst, MLX5_WSEG_SIZE);
> +			/* Note: no final wraparound check here. */
> +			return (struct mlx5_wqe_dseg *)pdst;
> +		}
> +		pdst = (uint8_t *)txq->wqes;
> +		buf += part;
> +		part = len;
> +	} while (true);
> +}
> +
> +/**
> + * Build the Ethernet Segment with optionally inlined data with
> + * VLAN insertion and following Data Segments (if any) from
> + * multi-segment packet. Used by ordinary send and TSO.
> + *
> + * @param txq
> + *   Pointer to TX queue structure.
> + * @param loc
> + *   Pointer to burst routine local context.
> + * @param wqe
> + *   Pointer to WQE to fill with built Ethernet/Data Segments.
> + * @param vlan
> + *   Length of VLAN header to insert, 0 means no VLAN insertion.
> + * @param inlen
> + *   Data length to inline. For TSO this parameter specifies
> + *   exact value, for ordinary send routine can be aligned by
> + *   caller to provide better WQE space saving and data buffer
> + *   start address alignment. This length includes VLAN header
> + *   being inserted.
> + * @param tso
> + *   Zero means ordinary send, inlined data can be extended,
> + *   otherwise this is TSO, inlined data length is fixed.
> + * @param olx
> + *   Configured Tx offloads mask. It is fully defined at
> + *   compile time and may be used for optimization.
> + *
> + * @return
> + *   Actual size of built WQE in segments.
> + */
> +static __rte_always_inline unsigned int
> +mlx5_tx_mseg_build(struct mlx5_txq_data *restrict txq,
> +		   struct mlx5_txq_local *restrict loc,
> +		   struct mlx5_wqe *restrict wqe,
> +		   unsigned int vlan,
> +		   unsigned int inlen,
> +		   unsigned int tso,
> +		   unsigned int olx __rte_unused)
> +{
> +	struct mlx5_wqe_dseg *restrict dseg;
> +	unsigned int ds;
> +
> +	assert((rte_pktmbuf_pkt_len(loc->mbuf) + vlan) >= inlen);
> +	loc->mbuf_nseg = NB_SEGS(loc->mbuf);
> +	loc->mbuf_off = 0;
> +
> +	dseg = mlx5_tx_eseg_mdat(txq, loc, wqe, vlan, inlen, tso, olx);
> +	if (!loc->mbuf_nseg)
> +		goto dseg_done;
> +	/*
> +	 * There are still some mbuf remaining, not inlined.
> +	 * The first mbuf may be partially inlined and we
> +	 * must process the possible non-zero data offset.
> +	 */
> +	if (loc->mbuf_off) {
> +		unsigned int dlen;
> +		uint8_t *dptr;
> +
> +		/*
> +		 * Exhausted packets must be dropped before.
> +		 * Non-zero offset means there are some data
> +		 * remained in the packet.
> +		 */
> +		assert(loc->mbuf_off < rte_pktmbuf_data_len(loc->mbuf));
> +		assert(rte_pktmbuf_data_len(loc->mbuf));
> +		dptr = rte_pktmbuf_mtod_offset(loc->mbuf, uint8_t *,
> +					       loc->mbuf_off);
> +		dlen = rte_pktmbuf_data_len(loc->mbuf) - loc->mbuf_off;
> +		/*
> +		 * Build the pointer/minimal data Data Segment.
> +		 * Do ring buffer wrapping check in advance.
> +		 */
> +		if ((uintptr_t)dseg >= (uintptr_t)txq->wqes_end)
> +			dseg = (struct mlx5_wqe_dseg *)txq->wqes;
> +		mlx5_tx_dseg_iptr(txq, loc, dseg, dptr, dlen, olx);
> +		/* Store the mbuf to be freed on completion. */
> +		assert(loc->elts_free);
> +		txq->elts[txq->elts_head++ & txq->elts_m] = loc->mbuf;
> +		--loc->elts_free;
> +		++dseg;
> +		if (--loc->mbuf_nseg == 0)
> +			goto dseg_done;
> +		loc->mbuf = loc->mbuf->next;
> +		loc->mbuf_off = 0;
> +	}
> +	do {
> +		if (unlikely(!rte_pktmbuf_data_len(loc->mbuf))) {
> +			struct rte_mbuf *mbuf;
> +
> +			/* Zero length segment found, just skip. */
> +			mbuf = loc->mbuf;
> +			loc->mbuf = loc->mbuf->next;
> +			rte_pktmbuf_free_seg(mbuf);
> +			if (--loc->mbuf_nseg == 0)
> +				break;
> +		} else {
> +			if ((uintptr_t)dseg >= (uintptr_t)txq->wqes_end)
> +				dseg = (struct mlx5_wqe_dseg *)txq->wqes;
> +			mlx5_tx_dseg_iptr
> +				(txq, loc, dseg,
> +				 rte_pktmbuf_mtod(loc->mbuf, uint8_t *),
> +				 rte_pktmbuf_data_len(loc->mbuf), olx);
> +			assert(loc->elts_free);
> +			txq->elts[txq->elts_head++ & txq->elts_m] = loc->mbuf;
> +			--loc->elts_free;
> +			++dseg;
> +			if (--loc->mbuf_nseg == 0)
> +				break;
> +			loc->mbuf = loc->mbuf->next;
> +		}
> +	} while (true);
> +
> +dseg_done:
> +	/* Calculate actual segments used from the dseg pointer. */
> +	if ((uintptr_t)wqe < (uintptr_t)dseg)
> +		ds = ((uintptr_t)dseg - (uintptr_t)wqe) / MLX5_WSEG_SIZE;
> +	else
> +		ds = (((uintptr_t)dseg - (uintptr_t)wqe) +
> +		      txq->wqe_s * MLX5_WQE_SIZE) / MLX5_WSEG_SIZE;
> +	return ds;
> +}
> +
> +/**
> + * Tx one packet function for multi-segment TSO. Supports all
> + * types of Tx offloads, uses MLX5_OPCODE_TSO to build WQEs,
> + * sends one packet per WQE.
> + *
> + * This routine is responsible for storing processed mbuf
> + * into elts ring buffer and update elts_head.
> + *
> + * @param txq
> + *   Pointer to TX queue structure.
> + * @param loc
> + *   Pointer to burst routine local context.
> + * @param olx
> + *   Configured Tx offloads mask. It is fully defined at
> + *   compile time and may be used for optimization.
> + *
> + * @return
> + *   MLX5_TXCMP_CODE_EXIT - sending is done or impossible.
> + *   MLX5_TXCMP_CODE_ERROR - some unrecoverable error occurred.
> + * Local context variables partially updated.
> + */
> +static __rte_always_inline enum mlx5_txcmp_code
> +mlx5_tx_packet_multi_tso(struct mlx5_txq_data *restrict txq,
> +			struct mlx5_txq_local *restrict loc,
> +			unsigned int olx)
> +{
> +	struct mlx5_wqe *restrict wqe;
> +	unsigned int ds, dlen, inlen, ntcp, vlan = 0;
> +
> +	/*
> +	 * Calculate data length to be inlined to estimate
> +	 * the required space in WQE ring buffer.
> +	 */
> +	dlen = rte_pktmbuf_pkt_len(loc->mbuf);
> +	if (MLX5_TXOFF_CONFIG(VLAN) && loc->mbuf->ol_flags & PKT_TX_VLAN_PKT)
> +		vlan = sizeof(struct rte_vlan_hdr);
> +	inlen = loc->mbuf->l2_len + vlan +
> +		loc->mbuf->l3_len + loc->mbuf->l4_len;
> +	if (unlikely((!inlen || !loc->mbuf->tso_segsz)))
> +		return MLX5_TXCMP_CODE_ERROR;
> +	if (loc->mbuf->ol_flags & PKT_TX_TUNNEL_MASK)
> +		inlen += loc->mbuf->outer_l2_len + loc->mbuf->outer_l3_len;
> +	/* Packet must contain all TSO headers. */
> +	if (unlikely(inlen > MLX5_MAX_TSO_HEADER ||
> +		     inlen <= MLX5_ESEG_MIN_INLINE_SIZE ||
> +		     inlen > (dlen + vlan)))
> +		return MLX5_TXCMP_CODE_ERROR;
> +	assert(inlen >= txq->inlen_mode);
> +	/*
> +	 * Check whether there are enough free WQEBBs:
> +	 * - Control Segment
> +	 * - Ethernet Segment
> +	 * - First Segment of inlined Ethernet data
> +	 * - ... data continued ...
> +	 * - Data Segments of pointer/min inline type
> +	 */
> +	ds = NB_SEGS(loc->mbuf) + 2 + (inlen -
> +				       MLX5_ESEG_MIN_INLINE_SIZE +
> +				       MLX5_WSEG_SIZE +
> +				       MLX5_WSEG_SIZE - 1) / MLX5_WSEG_SIZE;
> +	if (unlikely(loc->wqe_free < ((ds + 3) / 4)))
> +		return MLX5_TXCMP_CODE_EXIT;
> +	/* Check for maximal WQE size. */
> +	if (unlikely((MLX5_WQE_SIZE_MAX / MLX5_WSEG_SIZE) < ((ds + 3) / 4)))
> +		return MLX5_TXCMP_CODE_ERROR;
> +#ifdef MLX5_PMD_SOFT_COUNTERS
> +	/* Update sent data bytes/packets counters. */
> +	ntcp = (dlen - (inlen - vlan) + loc->mbuf->tso_segsz - 1) /
> +		loc->mbuf->tso_segsz;
> +	/*
> +	 * One will be added for mbuf itself
> +	 * at the end of the mlx5_tx_burst from
> +	 * loc->pkts_sent field.
> +	 */
> +	--ntcp;
> +	txq->stats.opackets += ntcp;
> +	txq->stats.obytes += dlen + vlan + ntcp * inlen;
> +#endif
> +	wqe = txq->wqes + (txq->wqe_ci & txq->wqe_m);
> +	loc->wqe_last = wqe;
> +	mlx5_tx_cseg_init(txq, loc, wqe, 0, MLX5_OPCODE_TSO, olx);
> +	ds = mlx5_tx_mseg_build(txq, loc, wqe, vlan, inlen, 1, olx);
> +	wqe->cseg.sq_ds = rte_cpu_to_be_32(txq->qp_num_8s | ds);
> +	txq->wqe_ci += (ds + 3) / 4;
> +	loc->wqe_free -= (ds + 3) / 4;
> +	return MLX5_TXCMP_CODE_MULTI;
> +}
> +
> +/**
> + * Tx one packet function for multi-segment SEND. Supports all
> + * types of Tx offloads, uses MLX5_OPCODE_SEND to build WQEs,
> + * sends one packet per WQE, without any data inlining in
> + * Ethernet Segment.
> + *
> + * This routine is responsible for storing processed mbuf
> + * into elts ring buffer and update elts_head.
> + *
> + * @param txq
> + *   Pointer to TX queue structure.
> + * @param loc
> + *   Pointer to burst routine local context.
> + * @param olx
> + *   Configured Tx offloads mask. It is fully defined at
> + *   compile time and may be used for optimization.
> + *
> + * @return
> + *   MLX5_TXCMP_CODE_EXIT - sending is done or impossible.
> + *   MLX5_TXCMP_CODE_ERROR - some unrecoverable error occurred.
> + * Local context variables partially updated.
> + */
> +static __rte_always_inline enum mlx5_txcmp_code
> +mlx5_tx_packet_multi_send(struct mlx5_txq_data *restrict txq,
> +			  struct mlx5_txq_local *restrict loc,
> +			  unsigned int olx)
> +{
> +	struct mlx5_wqe_dseg *restrict dseg;
> +	struct mlx5_wqe *restrict wqe;
> +	unsigned int ds, nseg;
> +
> +	assert(NB_SEGS(loc->mbuf) > 1);
> +	/*
> +	 * No inline at all, it means the CPU cycles saving
> +	 * is prioritized at configuration, we should not
> +	 * copy any packet data to WQE.
> +	 */
> +	nseg = NB_SEGS(loc->mbuf);
> +	ds = 2 + nseg;
> +	if (unlikely(loc->wqe_free < ((ds + 3) / 4)))
> +		return MLX5_TXCMP_CODE_EXIT;
> +	/* Check for maximal WQE size. */
> +	if (unlikely((MLX5_WQE_SIZE_MAX / MLX5_WSEG_SIZE) < ((ds + 3) / 4)))
> +		return MLX5_TXCMP_CODE_ERROR;
> +	/*
> +	 * Some Tx offloads may cause an error if
> +	 * packet is not long enough, check against
> +	 * assumed minimal length.
> +	 */
> +	if (rte_pktmbuf_pkt_len(loc->mbuf) <= MLX5_ESEG_MIN_INLINE_SIZE)
> +		return MLX5_TXCMP_CODE_ERROR;
> +#ifdef MLX5_PMD_SOFT_COUNTERS
> +	/* Update sent data bytes counter. */
> +	txq->stats.obytes += rte_pktmbuf_pkt_len(loc->mbuf);
> +	if (MLX5_TXOFF_CONFIG(VLAN) &&
> +	    loc->mbuf->ol_flags & PKT_TX_VLAN_PKT)
> +		txq->stats.obytes += sizeof(struct rte_vlan_hdr);
> +#endif
> +	/*
> +	 * SEND WQE, one WQEBB:
> +	 * - Control Segment, SEND opcode
> +	 * - Ethernet Segment, optional VLAN, no inline
> +	 * - Data Segments, pointer only type
> +	 */
> +	wqe = txq->wqes + (txq->wqe_ci & txq->wqe_m);
> +	loc->wqe_last = wqe;
> +	mlx5_tx_cseg_init(txq, loc, wqe, ds, MLX5_OPCODE_SEND, olx);
> +	mlx5_tx_eseg_none(txq, loc, wqe, olx);
> +	dseg = &wqe->dseg[0];
> +	do {
> +		if (unlikely(!rte_pktmbuf_data_len(loc->mbuf))) {
> +			struct rte_mbuf *mbuf;
> +
> +			/*
> +			 * Zero length segment found, have to
> +			 * correct total size of WQE in segments.
> +			 * It is supposed to be rare occasion, so
> +			 * in normal case (no zero length segments)
> +			 * we avoid extra writing to the Control
> +			 * Segment.
> +			 */
> +			--ds;
> +			wqe->cseg.sq_ds -= RTE_BE32(1);
> +			mbuf = loc->mbuf;
> +			loc->mbuf = mbuf->next;
> +			rte_pktmbuf_free_seg(mbuf);
> +			if (--nseg == 0)
> +				break;
> +		} else {
> +			mlx5_tx_dseg_ptr
> +				(txq, loc, dseg,
> +				 rte_pktmbuf_mtod(loc->mbuf, uint8_t *),
> +				 rte_pktmbuf_data_len(loc->mbuf), olx);
> +			txq->elts[txq->elts_head++ & txq->elts_m] = loc->mbuf;
> +			--loc->elts_free;
> +			if (--nseg == 0)
> +				break;
> +			++dseg;
> +			if ((uintptr_t)dseg >= (uintptr_t)txq->wqes_end)
> +				dseg = (struct mlx5_wqe_dseg *)txq->wqes;
> +			loc->mbuf = loc->mbuf->next;
> +		}
> +	} while (true);
> +	txq->wqe_ci += (ds + 3) / 4;
> +	loc->wqe_free -= (ds + 3) / 4;
> +	return MLX5_TXCMP_CODE_MULTI;
> +}
> +
> +/**
> + * Tx one packet function for multi-segment SEND. Supports all
> + * types of Tx offloads, uses MLX5_OPCODE_SEND to build WQEs,
> + * sends one packet per WQE, with data inlining in
> + * Ethernet Segment and minimal Data Segments.
> + *
> + * This routine is responsible for storing processed mbuf
> + * into elts ring buffer and update elts_head.
> + *
> + * @param txq
> + *   Pointer to TX queue structure.
> + * @param loc
> + *   Pointer to burst routine local context.
> + * @param olx
> + *   Configured Tx offloads mask. It is fully defined at
> + *   compile time and may be used for optimization.
> + *
> + * @return
> + *   MLX5_TXCMP_CODE_EXIT - sending is done or impossible.
> + *   MLX5_TXCMP_CODE_ERROR - some unrecoverable error occurred.
> + * Local context variables partially updated.
> + */
> +static __rte_always_inline enum mlx5_txcmp_code
> +mlx5_tx_packet_multi_inline(struct mlx5_txq_data *restrict txq,
> +			    struct mlx5_txq_local *restrict loc,
> +			    unsigned int olx)
> +{
> +	struct mlx5_wqe *restrict wqe;
> +	unsigned int ds, inlen, dlen, vlan = 0;
> +
> +	assert(MLX5_TXOFF_CONFIG(INLINE));
> +	assert(NB_SEGS(loc->mbuf) > 1);
> +	/*
> +	 * First calculate data length to be inlined
> +	 * to estimate the required space for WQE.
> +	 */
> +	dlen = rte_pktmbuf_pkt_len(loc->mbuf);
> +	if (MLX5_TXOFF_CONFIG(VLAN) && loc->mbuf->ol_flags & PKT_TX_VLAN_PKT)
> +		vlan = sizeof(struct rte_vlan_hdr);
> +	inlen = dlen + vlan;
> +	/* Check against minimal length. */
> +	if (inlen <= MLX5_ESEG_MIN_INLINE_SIZE)
> +		return MLX5_TXCMP_CODE_ERROR;
> +	assert(txq->inlen_send >= MLX5_ESEG_MIN_INLINE_SIZE);
> +	if (inlen > txq->inlen_send) {
> +		struct rte_mbuf *mbuf;
> +		unsigned int nxlen;
> +		uintptr_t start;
> +
> +		/*
> +		 * Packet length exceeds the allowed inline
> +		 * data length, check whether the minimal
> +		 * inlining is required.
> +		 */
> +		if (txq->inlen_mode) {
> +			assert(txq->inlen_mode >= MLX5_ESEG_MIN_INLINE_SIZE);
> +			assert(txq->inlen_mode <= txq->inlen_send);
> +			inlen = txq->inlen_mode;
> +		} else {
> +			if (!vlan || txq->vlan_en) {
> +				/*
> +				 * VLAN insertion will be done inside by HW.
> +				 * It is not utmost effective - VLAN flag is
> +				 * checked twice, but we should proceed the
> +				 * inlining length correctly and take into
> +				 * account the VLAN header being inserted.
> +				 */
> +				return mlx5_tx_packet_multi_send
> +							(txq, loc, olx);
> +			}
> +			inlen = MLX5_ESEG_MIN_INLINE_SIZE;
> +		}
> +		/*
> +		 * Now we know the minimal amount of data is requested
> +		 * to inline. Check whether we should inline the buffers
> +		 * from the chain beginning to eliminate some mbufs.
> +		 */
> +		mbuf = loc->mbuf;
> +		nxlen = rte_pktmbuf_data_len(mbuf);
> +		if (unlikely(nxlen <= txq->inlen_send)) {
> +			/* We can inline first mbuf at least. */
> +			if (nxlen < inlen) {
> +				unsigned int smlen;
> +
> +				/* Scan mbufs till inlen filled. */
> +				do {
> +					smlen = nxlen;
> +					mbuf = NEXT(mbuf);
> +					assert(mbuf);
> +					nxlen = rte_pktmbuf_data_len(mbuf);
> +					nxlen += smlen;
> +				} while (unlikely(nxlen < inlen));
> +				if (unlikely(nxlen > txq->inlen_send)) {
> +					/* We cannot inline entire mbuf. */
> +					smlen = inlen - smlen;
> +					start = rte_pktmbuf_mtod_offset
> +						    (mbuf, uintptr_t, smlen);
> +					goto do_align;
> +				}
> +			}
> +			do {
> +				inlen = nxlen;
> +				mbuf = NEXT(mbuf);
> +				/* There should be not end of packet. */
> +				assert(mbuf);
> +				nxlen = inlen + rte_pktmbuf_data_len(mbuf);
> +			} while (unlikely(nxlen < txq->inlen_send));
> +		}
> +		start = rte_pktmbuf_mtod(mbuf, uintptr_t);
> +		/*
> +		 * Check whether we can do inline to align start
> +		 * address of data buffer to cacheline.
> +		 */
> +do_align:
> +		start = (~start + 1) & (RTE_CACHE_LINE_SIZE - 1);
> +		if (unlikely(start)) {
> +			start += inlen;
> +			if (start <= txq->inlen_send)
> +				inlen = start;
> +		}
> +	}
> +	/*
> +	 * Check whether there are enough free WQEBBs:
> +	 * - Control Segment
> +	 * - Ethernet Segment
> +	 * - First Segment of inlined Ethernet data
> +	 * - ... data continued ...
> +	 * - Data Segments of pointer/min inline type
> +	 *
> +	 * Estimate the number of Data Segments conservatively,
> +	 * supposing no any mbufs is being freed during inlining.
> +	 */
> +	assert(inlen <= txq->inlen_send);
> +	ds = NB_SEGS(loc->mbuf) + 2 + (inlen -
> +				       MLX5_ESEG_MIN_INLINE_SIZE +
> +				       MLX5_WSEG_SIZE +
> +				       MLX5_WSEG_SIZE - 1) / MLX5_WSEG_SIZE;
> +	if (unlikely(loc->wqe_free < ((ds + 3) / 4)))
> +		return MLX5_TXCMP_CODE_EXIT;
> +	/* Check for maximal WQE size. */
> +	if (unlikely((MLX5_WQE_SIZE_MAX / MLX5_WSEG_SIZE) < ((ds + 3) / 4)))
> +		return MLX5_TXCMP_CODE_ERROR;
> +#ifdef MLX5_PMD_SOFT_COUNTERS
> +	/* Update sent data bytes/packets counters. */
> +	txq->stats.obytes += dlen + vlan;
> +#endif
> +	wqe = txq->wqes + (txq->wqe_ci & txq->wqe_m);
> +	loc->wqe_last = wqe;
> +	mlx5_tx_cseg_init(txq, loc, wqe, 0, MLX5_OPCODE_SEND, olx);
> +	ds = mlx5_tx_mseg_build(txq, loc, wqe, vlan, inlen, 0, olx);
> +	wqe->cseg.sq_ds = rte_cpu_to_be_32(txq->qp_num_8s | ds);
> +	txq->wqe_ci += (ds + 3) / 4;
> +	loc->wqe_free -= (ds + 3) / 4;
> +	return MLX5_TXCMP_CODE_MULTI;
> +}
> +
> +/**
> + * Tx burst function for multi-segment packets. Supports all
> + * types of Tx offloads, uses MLX5_OPCODE_SEND/TSO to build WQEs,
> + * sends one packet per WQE. Function stops sending if it
> + * encounters the single-segment packet.
> + *
> + * This routine is responsible for storing processed mbuf
> + * into elts ring buffer and update elts_head.
> + *
> + * @param txq
> + *   Pointer to TX queue structure.
> + * @param[in] pkts
> + *   Packets to transmit.
> + * @param pkts_n
> + *   Number of packets in array.
> + * @param loc
> + *   Pointer to burst routine local context.
> + * @param olx
> + *   Configured Tx offloads mask. It is fully defined at
> + *   compile time and may be used for optimization.
> + *
> + * @return
> + *   MLX5_TXCMP_CODE_EXIT - sending is done or impossible.
> + *   MLX5_TXCMP_CODE_ERROR - some unrecoverable error occurred.
> + *   MLX5_TXCMP_CODE_SINGLE - single-segment packet encountered.
> + *   MLX5_TXCMP_CODE_TSO - TSO single-segment packet encountered.
> + * Local context variables updated.
> + */
> +static __rte_always_inline enum mlx5_txcmp_code
> +mlx5_tx_burst_mseg(struct mlx5_txq_data *restrict txq,
> +		   struct rte_mbuf **restrict pkts,
> +		   unsigned int pkts_n,
> +		   struct mlx5_txq_local *restrict loc,
> +		   unsigned int olx)
> +{
> +	assert(loc->elts_free && loc->wqe_free);
> +	assert(pkts_n > loc->pkts_sent);
> +	pkts += loc->pkts_sent + 1;
> +	pkts_n -= loc->pkts_sent;
> +	for (;;) {
> +		enum mlx5_txcmp_code ret;
> +
> +		assert(NB_SEGS(loc->mbuf) > 1);
> +		/*
> +		 * Estimate the number of free elts quickly but
> +		 * conservatively. Some segment may be fully inlined
> +		 * and freed, ignore this here - precise estimation
> +		 * is costly.
> +		 */
> +		if (loc->elts_free < NB_SEGS(loc->mbuf))
> +			return MLX5_TXCMP_CODE_EXIT;
> +		if (MLX5_TXOFF_CONFIG(TSO) &&
> +		    unlikely(loc->mbuf->ol_flags & PKT_TX_TCP_SEG)) {
> +			/* Proceed with multi-segment TSO. */
> +			ret = mlx5_tx_packet_multi_tso(txq, loc, olx);
> +		} else if (MLX5_TXOFF_CONFIG(INLINE)) {
> +			/* Proceed with multi-segment SEND with inlining. */
> +			ret = mlx5_tx_packet_multi_inline(txq, loc, olx);
> +		} else {
> +			/* Proceed with multi-segment SEND w/o inlining. */
> +			ret = mlx5_tx_packet_multi_send(txq, loc, olx);
> +		}
> +		if (ret == MLX5_TXCMP_CODE_EXIT)
> +			return MLX5_TXCMP_CODE_EXIT;
> +		if (ret == MLX5_TXCMP_CODE_ERROR)
> +			return MLX5_TXCMP_CODE_ERROR;
> +		/* WQE is built, go to the next packet. */
> +		++loc->pkts_sent;
> +		--pkts_n;
> +		if (unlikely(!pkts_n || !loc->elts_free || !loc->wqe_free))
> +			return MLX5_TXCMP_CODE_EXIT;
> +		loc->mbuf = *pkts++;
> +		if (pkts_n > 1)
> +			rte_prefetch0(*pkts);
> +		if (likely(NB_SEGS(loc->mbuf) > 1))
> +			continue;
> +		/* Here ends the series of multi-segment packets. */
> +		if (MLX5_TXOFF_CONFIG(TSO) &&
> +		    unlikely(!(loc->mbuf->ol_flags & PKT_TX_TCP_SEG)))
> +			return MLX5_TXCMP_CODE_TSO;
> +		return MLX5_TXCMP_CODE_SINGLE;
> +	}
> +	assert(false);
> +}
> +
> +/**
> + * Tx burst function for single-segment packets with TSO.
> + * Supports all types of Tx offloads, except multi-packets.
> + * Uses MLX5_OPCODE_TSO to build WQEs, sends one packet per WQE.
> + * Function stops sending if it encounters the multi-segment
> + * packet or packet without TSO requested.
> + *
> + * The routine is responsible for storing processed mbuf
> + * into elts ring buffer and update elts_head if inline
> + * offloads is requested due to possible early freeing
> + * of the inlined mbufs (can not store pkts array in elts
> + * as a batch).
> + *
> + * @param txq
> + *   Pointer to TX queue structure.
> + * @param[in] pkts
> + *   Packets to transmit.
> + * @param pkts_n
> + *   Number of packets in array.
> + * @param loc
> + *   Pointer to burst routine local context.
> + * @param olx
> + *   Configured Tx offloads mask. It is fully defined at
> + *   compile time and may be used for optimization.
> + *
> + * @return
> + *   MLX5_TXCMP_CODE_EXIT - sending is done or impossible.
> + *   MLX5_TXCMP_CODE_ERROR - some unrecoverable error occurred.
> + *   MLX5_TXCMP_CODE_SINGLE - single-segment packet encountered.
> + *   MLX5_TXCMP_CODE_MULTI - multi-segment packet encountered.
> + * Local context variables updated.
> + */
> +static __rte_always_inline enum mlx5_txcmp_code
> +mlx5_tx_burst_tso(struct mlx5_txq_data *restrict txq,
> +		  struct rte_mbuf **restrict pkts,
> +		  unsigned int pkts_n,
> +		  struct mlx5_txq_local *restrict loc,
> +		  unsigned int olx)
> +{
> +	assert(loc->elts_free && loc->wqe_free);
> +	assert(pkts_n > loc->pkts_sent);
> +	pkts += loc->pkts_sent + 1;
> +	pkts_n -= loc->pkts_sent;
> +	for (;;) {
> +		struct mlx5_wqe_dseg *restrict dseg;
> +		struct mlx5_wqe *restrict wqe;
> +		unsigned int ds, dlen, hlen, ntcp, vlan = 0;
> +		uint8_t *dptr;
> +
> +		assert(NB_SEGS(loc->mbuf) == 1);
> +		dlen = rte_pktmbuf_data_len(loc->mbuf);
> +		if (MLX5_TXOFF_CONFIG(VLAN) &&
> +		    loc->mbuf->ol_flags & PKT_TX_VLAN_PKT) {
> +			vlan = sizeof(struct rte_vlan_hdr);
> +		}
> +		/*
> +		 * First calculate the WQE size to check
> +		 * whether we have enough space in ring buffer.
> +		 */
> +		hlen = loc->mbuf->l2_len + vlan +
> +		       loc->mbuf->l3_len + loc->mbuf->l4_len;
> +		if (unlikely((!hlen || !loc->mbuf->tso_segsz)))
> +			return MLX5_TXCMP_CODE_ERROR;
> +		if (loc->mbuf->ol_flags & PKT_TX_TUNNEL_MASK)
> +			hlen += loc->mbuf->outer_l2_len +
> +				loc->mbuf->outer_l3_len;
> +		/* Segment must contain all TSO headers. */
> +		if (unlikely(hlen > MLX5_MAX_TSO_HEADER ||
> +			     hlen <= MLX5_ESEG_MIN_INLINE_SIZE ||
> +			     hlen > (dlen + vlan)))
> +			return MLX5_TXCMP_CODE_ERROR;
> +		/*
> +		 * Check whether there are enough free WQEBBs:
> +		 * - Control Segment
> +		 * - Ethernet Segment
> +		 * - First Segment of inlined Ethernet data
> +		 * - ... data continued ...
> +		 * - Finishing Data Segment of pointer type
> +		 */
> +		ds = 4 + (hlen - MLX5_ESEG_MIN_INLINE_SIZE +
> +			  MLX5_WSEG_SIZE - 1) / MLX5_WSEG_SIZE;
> +		if (loc->wqe_free < ((ds + 3) / 4))
> +			return MLX5_TXCMP_CODE_EXIT;
> +#ifdef MLX5_PMD_SOFT_COUNTERS
> +		/* Update sent data bytes/packets counters. */
> +		ntcp = (dlen + vlan - hlen +
> +			loc->mbuf->tso_segsz - 1) /
> +			loc->mbuf->tso_segsz;
> +		/*
> +		 * One will be added for mbuf itself at the end
> +		 * of the mlx5_tx_burst from loc->pkts_sent field.
> +		 */
> +		--ntcp;
> +		txq->stats.opackets += ntcp;
> +		txq->stats.obytes += dlen + vlan + ntcp * hlen;
> +#endif
> +		/*
> +		 * Build the TSO WQE:
> +		 * - Control Segment
> +		 * - Ethernet Segment with hlen bytes inlined
> +		 * - Data Segment of pointer type
> +		 */
> +		wqe = txq->wqes + (txq->wqe_ci & txq->wqe_m);
> +		loc->wqe_last = wqe;
> +		mlx5_tx_cseg_init(txq, loc, wqe, ds,
> +				  MLX5_OPCODE_TSO, olx);
> +		dseg = mlx5_tx_eseg_data(txq, loc, wqe, vlan, hlen, 1, olx);
> +		dptr = rte_pktmbuf_mtod(loc->mbuf, uint8_t *) + hlen - vlan;
> +		dlen -= hlen - vlan;
> +		mlx5_tx_dseg_ptr(txq, loc, dseg, dptr, dlen, olx);
> +		/*
> +		 * WQE is built, update the loop parameters
> +		 * and go to the next packet.
> +		 */
> +		txq->wqe_ci += (ds + 3) / 4;
> +		loc->wqe_free -= (ds + 3) / 4;
> +		if (MLX5_TXOFF_CONFIG(INLINE))
> +			txq->elts[txq->elts_head++ & txq->elts_m] = loc->mbuf;
> +		--loc->elts_free;
> +		++loc->pkts_sent;
> +		--pkts_n;
> +		if (unlikely(!pkts_n || !loc->elts_free || !loc->wqe_free))
> +			return MLX5_TXCMP_CODE_EXIT;
> +		loc->mbuf = *pkts++;
> +		if (pkts_n > 1)
> +			rte_prefetch0(*pkts);
> +		if (MLX5_TXOFF_CONFIG(MULTI) &&
> +		    unlikely(NB_SEGS(loc->mbuf) > 1))
> +			return MLX5_TXCMP_CODE_MULTI;
> +		if (unlikely(!(loc->mbuf->ol_flags & PKT_TX_TCP_SEG)))
> +			return MLX5_TXCMP_CODE_SINGLE;
> +		/* Continue with the next TSO packet. */
> +	}
> +	assert(false);
> +}
> +
> +/**
> + * Analyze the packet and select the best method to send.
> + *
> + * @param txq
> + *   Pointer to TX queue structure.
> + * @param loc
> + *   Pointer to burst routine local context.
> + * @param olx
> + *   Configured Tx offloads mask. It is fully defined at
> + *   compile time and may be used for optimization.
> + * @param newp
> + *   The predefined flag whether do complete check for
> + *   multi-segment packets and TSO.
> + *
> + * @return
> + *  MLX5_TXCMP_CODE_MULTI - multi-segment packet encountered.
> + *  MLX5_TXCMP_CODE_TSO - TSO required, use TSO/LSO.
> + *  MLX5_TXCMP_CODE_SINGLE - single-segment packet, use SEND.
> + *  MLX5_TXCMP_CODE_EMPW - single-segment packet, use MPW.
> + */
> +static __rte_always_inline enum mlx5_txcmp_code
> +mlx5_tx_able_to_empw(struct mlx5_txq_data *restrict txq,
> +		     struct mlx5_txq_local *restrict loc,
> +		     unsigned int olx,
> +		     bool newp)
> +{
> +	/* Check for multi-segment packet. */
> +	if (newp &&
> +	    MLX5_TXOFF_CONFIG(MULTI) &&
> +	    unlikely(NB_SEGS(loc->mbuf) > 1))
> +		return MLX5_TXCMP_CODE_MULTI;
> +	/* Check for TSO packet. */
> +	if (newp &&
> +	    MLX5_TXOFF_CONFIG(TSO) &&
> +	    unlikely(loc->mbuf->ol_flags & PKT_TX_TCP_SEG))
> +		return MLX5_TXCMP_CODE_TSO;
> +	/* Check if eMPW is enabled at all. */
> +	if (!MLX5_TXOFF_CONFIG(EMPW))
> +		return MLX5_TXCMP_CODE_SINGLE;
> +	/* Check if eMPW can be engaged. */
> +	if (MLX5_TXOFF_CONFIG(VLAN) &&
> +	    unlikely(loc->mbuf->ol_flags & PKT_TX_VLAN_PKT) &&
> +		(!MLX5_TXOFF_CONFIG(INLINE) ||
> +		 unlikely((rte_pktmbuf_data_len(loc->mbuf) +
> +			   sizeof(struct rte_vlan_hdr)) > txq->inlen_empw))) {
> +		/*
> +		 * eMPW does not support VLAN insertion offload,
> +		 * we have to inline the entire packet but
> +		 * packet is too long for inlining.
> +		 */
> +		return MLX5_TXCMP_CODE_SINGLE;
> +	}
> +	return MLX5_TXCMP_CODE_EMPW;
> +}
> +
> +/**
> + * Check the next packet attributes to match with the eMPW batch ones.
> + *
> + * @param txq
> + *   Pointer to TX queue structure.
> + * @param es
> + *   Pointer to Ethernet Segment of eMPW batch.
> + * @param loc
> + *   Pointer to burst routine local context.
> + * @param olx
> + *   Configured Tx offloads mask. It is fully defined at
> + *   compile time and may be used for optimization.
> + *
> + * @return
> + *  true - packet match with eMPW batch attributes.
> + *  false - no match, eMPW should be restarted.
> + */
> +static __rte_always_inline bool
> +mlx5_tx_match_empw(struct mlx5_txq_data *restrict txq __rte_unused,
> +		   struct mlx5_wqe_eseg *restrict es,
> +		   struct mlx5_txq_local *restrict loc,
> +		   unsigned int olx)
> +{
> +	uint8_t swp_flags = 0;
> +
> +	/* Compare the checksum flags, if any. */
> +	if (MLX5_TXOFF_CONFIG(CSUM) &&
> +	    txq_ol_cksum_to_cs(loc->mbuf) != es->cs_flags)
> +		return false;
> +	/* Compare the Software Parser offsets and flags. */
> +	if (MLX5_TXOFF_CONFIG(SWP) &&
> +	    (es->swp_offs != txq_mbuf_to_swp(loc, &swp_flags, olx) ||
> +	     es->swp_flags != swp_flags))
> +		return false;
> +	/* Fill metadata field if needed. */
> +	if (MLX5_TXOFF_CONFIG(METADATA) &&
> +		es->metadata != (loc->mbuf->ol_flags & PKT_TX_METADATA ?
> +				 loc->mbuf->tx_metadata : 0))
> +		return false;
> +	/* There must be no VLAN packets in eMPW loop. */
> +	if (MLX5_TXOFF_CONFIG(VLAN))
> +		assert(!(loc->mbuf->ol_flags & PKT_TX_VLAN_PKT));
> +	return true;
> +}
> +
> +/*
> + * Update send loop variables and WQE for eMPW loop
> + * without data inlining. Number of Data Segments is
> + * equal to the number of sent packets.
> + *
> + * @param txq
> + *   Pointer to TX queue structure.
> + * @param loc
> + *   Pointer to burst routine local context.
> + * @param ds
> + *   Number of packets/Data Segments/Packets.
> + * @param slen
> + *   Accumulated statistics, bytes sent
> + * @param olx
> + *   Configured Tx offloads mask. It is fully defined at
> + *   compile time and may be used for optimization.
> + *
> + * @return
> + *  true - packet match with eMPW batch attributes.
> + *  false - no match, eMPW should be restarted.
> + */
> +static __rte_always_inline void
> +mlx5_tx_sdone_empw(struct mlx5_txq_data *restrict txq,
> +		   struct mlx5_txq_local *restrict loc,
> +		   unsigned int ds,
> +		   unsigned int slen,
> +		   unsigned int olx __rte_unused)
> +{
> +	assert(!MLX5_TXOFF_CONFIG(INLINE));
> +#ifdef MLX5_PMD_SOFT_COUNTERS
> +	/* Update sent data bytes counter. */
> +	 txq->stats.obytes += slen;
> +#else
> +	(void)slen;
> +#endif
> +	loc->elts_free -= ds;
> +	loc->pkts_sent += ds;
> +	ds += 2;
> +	loc->wqe_last->cseg.sq_ds = rte_cpu_to_be_32(txq->qp_num_8s | ds);
> +	txq->wqe_ci += (ds + 3) / 4;
> +	loc->wqe_free -= (ds + 3) / 4;
> +}
> +
> +/*
> + * Update send loop variables and WQE for eMPW loop
> + * with data inlining. Gets the size of pushed descriptors
> + * and data to the WQE.
> + *
> + * @param txq
> + *   Pointer to TX queue structure.
> + * @param loc
> + *   Pointer to burst routine local context.
> + * @param len
> + *   Total size of descriptor/data in bytes.
> + * @param slen
> + *   Accumulated statistics, data bytes sent.
> + * @param olx
> + *   Configured Tx offloads mask. It is fully defined at
> + *   compile time and may be used for optimization.
> + *
> + * @return
> + *  true - packet match with eMPW batch attributes.
> + *  false - no match, eMPW should be restarted.
> + */
> +static __rte_always_inline void
> +mlx5_tx_idone_empw(struct mlx5_txq_data *restrict txq,
> +		   struct mlx5_txq_local *restrict loc,
> +		   unsigned int len,
> +		   unsigned int slen,
> +		   unsigned int olx __rte_unused)
> +{
> +	assert(MLX5_TXOFF_CONFIG(INLINE));
> +	assert((len % MLX5_WSEG_SIZE) == 0);
> +#ifdef MLX5_PMD_SOFT_COUNTERS
> +	/* Update sent data bytes counter. */
> +	 txq->stats.obytes += slen;
> +#else
> +	(void)slen;
> +#endif
> +	len = len / MLX5_WSEG_SIZE + 2;
> +	loc->wqe_last->cseg.sq_ds = rte_cpu_to_be_32(txq->qp_num_8s | len);
> +	txq->wqe_ci += (len + 3) / 4;
> +	loc->wqe_free -= (len + 3) / 4;
> +}
> +
> +/**
> + * The set of Tx burst functions for single-segment packets
> + * without TSO and with Multi-Packet Writing feature support.
> + * Supports all types of Tx offloads, except multi-packets
> + * and TSO.
> + *
> + * Uses MLX5_OPCODE_EMPW to build WQEs if possible and sends
> + * as many packet per WQE as it can. If eMPW is not configured
> + * or packet can not be sent with eMPW (VLAN insertion) the
> + * ordinary SEND opcode is used and only one packet placed
> + * in WQE.
> + *
> + * Functions stop sending if it encounters the multi-segment
> + * packet or packet with TSO requested.
> + *
> + * The routines are responsible for storing processed mbuf
> + * into elts ring buffer and update elts_head if inlining
> + * offload is requested. Otherwise the copying mbufs to elts
> + * can be postponed and completed at the end of burst routine.
> + *
> + * @param txq
> + *   Pointer to TX queue structure.
> + * @param[in] pkts
> + *   Packets to transmit.
> + * @param pkts_n
> + *   Number of packets in array.
> + * @param loc
> + *   Pointer to burst routine local context.
> + * @param olx
> + *   Configured Tx offloads mask. It is fully defined at
> + *   compile time and may be used for optimization.
> + *
> + * @return
> + *   MLX5_TXCMP_CODE_EXIT - sending is done or impossible.
> + *   MLX5_TXCMP_CODE_ERROR - some unrecoverable error occurred.
> + *   MLX5_TXCMP_CODE_MULTI - multi-segment packet encountered.
> + *   MLX5_TXCMP_CODE_TSO - TSO packet encountered.
> + *   MLX5_TXCMP_CODE_SINGLE - used inside functions set.
> + *   MLX5_TXCMP_CODE_EMPW - used inside functions set.
> + *
> + * Local context variables updated.
> + *
> + *
> + * The routine sends packets with MLX5_OPCODE_EMPW
> + * without inlining, this is dedicated optimized branch.
> + * No VLAN insertion is supported.
> + */
> +static __rte_always_inline enum mlx5_txcmp_code
> +mlx5_tx_burst_empw_simple(struct mlx5_txq_data *restrict txq,
> +			  struct rte_mbuf **restrict pkts,
> +			  unsigned int pkts_n,
> +			  struct mlx5_txq_local *restrict loc,
> +			  unsigned int olx)
> +{
> +	/*
> +	 * Subroutine is the part of mlx5_tx_burst_single()
> +	 * and sends single-segment packet with eMPW opcode
> +	 * without data inlining.
> +	 */
> +	assert(!MLX5_TXOFF_CONFIG(INLINE));
> +	assert(MLX5_TXOFF_CONFIG(EMPW));
> +	assert(loc->elts_free && loc->wqe_free);
> +	assert(pkts_n > loc->pkts_sent);
> +	static_assert(MLX5_EMPW_MIN_PACKETS >= 2, "invalid min size");
> +	pkts += loc->pkts_sent + 1;
> +	pkts_n -= loc->pkts_sent;
> +	for (;;) {
> +		struct mlx5_wqe_dseg *restrict dseg;
> +		struct mlx5_wqe_eseg *restrict eseg;
> +		enum mlx5_txcmp_code ret;
> +		unsigned int part, loop;
> +		unsigned int slen = 0;
> +
> +next_empw:
> +		part = RTE_MIN(pkts_n, MLX5_EMPW_MAX_PACKETS);
> +		if (unlikely(loc->elts_free < part)) {
> +			/* We have no enough elts to save all mbufs. */
> +			if (unlikely(loc->elts_free < MLX5_EMPW_MIN_PACKETS))
> +				return MLX5_TXCMP_CODE_EXIT;
> +			/* But we still able to send at least minimal eMPW. */
> +			part = loc->elts_free;
> +		}
> +		/* Check whether we have enough WQEs */
> +		if (unlikely(loc->wqe_free < ((2 + part + 3) / 4))) {
> +			if (unlikely(loc->wqe_free <
> +				((2 + MLX5_EMPW_MIN_PACKETS + 3) / 4)))
> +				return MLX5_TXCMP_CODE_EXIT;
> +			part = (loc->wqe_free * 4) - 2;
> +		}
> +		if (likely(part > 1))
> +			rte_prefetch0(*pkts);
> +		loc->wqe_last = txq->wqes + (txq->wqe_ci & txq->wqe_m);
> +		/*
> +		 * Build eMPW title WQEBB:
> +		 * - Control Segment, eMPW opcode
> +		 * - Ethernet Segment, no inline
> +		 */
> +		mlx5_tx_cseg_init(txq, loc, loc->wqe_last, part + 2,
> +				  MLX5_OPCODE_ENHANCED_MPSW, olx);
> +		mlx5_tx_eseg_none(txq, loc, loc->wqe_last,
> +				  olx & ~MLX5_TXOFF_CONFIG_VLAN);
> +		eseg = &loc->wqe_last->eseg;
> +		dseg = &loc->wqe_last->dseg[0];
> +		loop = part;
> +		for (;;) {
> +			uint32_t dlen = rte_pktmbuf_data_len(loc->mbuf);
> +#ifdef MLX5_PMD_SOFT_COUNTERS
> +			/* Update sent data bytes counter. */
> +			slen += dlen;
> +#endif
> +			mlx5_tx_dseg_ptr
> +				(txq, loc, dseg,
> +				 rte_pktmbuf_mtod(loc->mbuf, uint8_t *),
> +				 dlen, olx);
> +			if (unlikely(--loop == 0))
> +				break;
> +			loc->mbuf = *pkts++;
> +			if (likely(loop > 1))
> +				rte_prefetch0(*pkts);
> +			ret = mlx5_tx_able_to_empw(txq, loc, olx, true);
> +			/*
> +			 * Unroll the completion code to avoid
> +			 * returning variable value - it results in
> +			 * unoptimized sequent checking in caller.
> +			 */
> +			if (ret == MLX5_TXCMP_CODE_MULTI) {
> +				part -= loop;
> +				mlx5_tx_sdone_empw(txq, loc, part, slen, olx);
> +				if (unlikely(!loc->elts_free ||
> +					     !loc->wqe_free))
> +					return MLX5_TXCMP_CODE_EXIT;
> +				return MLX5_TXCMP_CODE_MULTI;
> +			}
> +			if (ret == MLX5_TXCMP_CODE_TSO) {
> +				part -= loop;
> +				mlx5_tx_sdone_empw(txq, loc, part, slen, olx);
> +				if (unlikely(!loc->elts_free ||
> +					     !loc->wqe_free))
> +					return MLX5_TXCMP_CODE_EXIT;
> +				return MLX5_TXCMP_CODE_TSO;
> +			}
> +			if (ret == MLX5_TXCMP_CODE_SINGLE) {
> +				part -= loop;
> +				mlx5_tx_sdone_empw(txq, loc, part, slen, olx);
> +				if (unlikely(!loc->elts_free ||
> +					     !loc->wqe_free))
> +					return MLX5_TXCMP_CODE_EXIT;
> +				return MLX5_TXCMP_CODE_SINGLE;
> +			}
> +			if (ret != MLX5_TXCMP_CODE_EMPW) {
> +				assert(false);
> +				part -= loop;
> +				mlx5_tx_sdone_empw(txq, loc, part, slen, olx);
> +				return MLX5_TXCMP_CODE_ERROR;
> +			}
> +			/*
> +			 * Check whether packet parameters coincide
> +			 * within assumed eMPW batch:
> +			 * - check sum settings
> +			 * - metadata value
> +			 * - software parser settings
> +			 */
> +			if (!mlx5_tx_match_empw(txq, eseg, loc, olx)) {
> +				assert(loop);
> +				part -= loop;
> +				mlx5_tx_sdone_empw(txq, loc, part, slen, olx);
> +				if (unlikely(!loc->elts_free ||
> +					     !loc->wqe_free))
> +					return MLX5_TXCMP_CODE_EXIT;
> +				goto next_empw;
> +			}
> +			/* Packet attributes match, continue the same eMPW. */
> +			++dseg;
> +			if ((uintptr_t)dseg >= (uintptr_t)txq->wqes_end)
> +				dseg = (struct mlx5_wqe_dseg *)txq->wqes;
> +		}
> +		/* eMPW is built successfully, update loop parameters. */
> +		assert(!loop);
> +		assert(pkts_n >= part);
> +#ifdef MLX5_PMD_SOFT_COUNTERS
> +		/* Update sent data bytes counter. */
> +		txq->stats.obytes += slen;
> +#endif
> +		loc->elts_free -= part;
> +		loc->pkts_sent += part;
> +		txq->wqe_ci += (2 + part + 3) / 4;
> +		loc->wqe_free -= (2 + part + 3) / 4;
> +		pkts_n -= part;
> +		if (unlikely(!pkts_n || !loc->elts_free || !loc->wqe_free))
> +			return MLX5_TXCMP_CODE_EXIT;
> +		loc->mbuf = *pkts++;
> +		ret = mlx5_tx_able_to_empw(txq, loc, olx, true);
> +		if (unlikely(ret != MLX5_TXCMP_CODE_EMPW))
> +			return ret;
> +		/* Continue sending eMPW batches. */
> +	}
> +	assert(false);
> +}
> +
> +/**
> + * The routine sends packets with MLX5_OPCODE_EMPW
> + * with inlining, optionally supports VLAN insertion.
> + */
> +static __rte_always_inline enum mlx5_txcmp_code
> +mlx5_tx_burst_empw_inline(struct mlx5_txq_data *restrict txq,
> +			  struct rte_mbuf **restrict pkts,
> +			  unsigned int pkts_n,
> +			  struct mlx5_txq_local *restrict loc,
> +			  unsigned int olx)
> +{
> +	/*
> +	 * Subroutine is the part of mlx5_tx_burst_single()
> +	 * and sends single-segment packet with eMPW opcode
> +	 * with data inlining.
> +	 */
> +	assert(MLX5_TXOFF_CONFIG(INLINE));
> +	assert(MLX5_TXOFF_CONFIG(EMPW));
> +	assert(loc->elts_free && loc->wqe_free);
> +	assert(pkts_n > loc->pkts_sent);
> +	static_assert(MLX5_EMPW_MIN_PACKETS >= 2, "invalid min size");
> +	pkts += loc->pkts_sent + 1;
> +	pkts_n -= loc->pkts_sent;
> +	for (;;) {
> +		struct mlx5_wqe_dseg *restrict dseg;
> +		struct mlx5_wqe_eseg *restrict eseg;
> +		enum mlx5_txcmp_code ret;
> +		unsigned int room, part;
> +		unsigned int slen = 0;
> +
> +next_empw:
> +		/* Check whether we have minimal amount WQEs */
> +		if (unlikely(loc->wqe_free <
> +			    ((2 + MLX5_EMPW_MIN_PACKETS + 3) / 4)))
> +			return MLX5_TXCMP_CODE_EXIT;
> +		if (likely(pkts_n > 1))
> +			rte_prefetch0(*pkts);
> +		loc->wqe_last = txq->wqes + (txq->wqe_ci & txq->wqe_m);
> +		/*
> +		 * Build eMPW title WQEBB:
> +		 * - Control Segment, eMPW opcode, zero DS
> +		 * - Ethernet Segment, no inline
> +		 */
> +		mlx5_tx_cseg_init(txq, loc, loc->wqe_last, 0,
> +				  MLX5_OPCODE_ENHANCED_MPSW, olx);
> +		mlx5_tx_eseg_none(txq, loc, loc->wqe_last,
> +				  olx & ~MLX5_TXOFF_CONFIG_VLAN);
> +		eseg = &loc->wqe_last->eseg;
> +		dseg = &loc->wqe_last->dseg[0];
> +		room = RTE_MIN(MLX5_WQE_SIZE_MAX / MLX5_WQE_SIZE,
> +			       loc->wqe_free) * MLX5_WQE_SIZE -
> +					MLX5_WQE_CSEG_SIZE -
> +					MLX5_WQE_ESEG_SIZE;
> +		/* Build WQE till we have space, packets and resources. */
> +		part = room;
> +		for (;;) {
> +			uint32_t dlen = rte_pktmbuf_data_len(loc->mbuf);
> +			uint8_t *dptr = rte_pktmbuf_mtod(loc->mbuf, uint8_t *);
> +			unsigned int tlen;
> +
> +			assert(room >= MLX5_WQE_DSEG_SIZE);
> +			assert((room % MLX5_WQE_DSEG_SIZE) == 0);
> +			assert((uintptr_t)dseg < (uintptr_t)txq->wqes_end);
> +			/*
> +			 * Some Tx offloads may cause an error if
> +			 * packet is not long enough, check against
> +			 * assumed minimal length.
> +			 */
> +			if (unlikely(dlen <= MLX5_ESEG_MIN_INLINE_SIZE)) {
> +				part -= room;
> +				if (unlikely(!part))
> +					return MLX5_TXCMP_CODE_ERROR;
> +				/*
> +				 * We have some successfully built
> +				 * packet Data Segments to send.
> +				 */
> +				mlx5_tx_idone_empw(txq, loc, part, slen, olx);
> +				return MLX5_TXCMP_CODE_ERROR;
> +			}
> +			/* Inline or not inline - that's the Question. */
> +			if (dlen > txq->inlen_empw)
> +				goto pointer_empw;
> +			/* Inline entire packet, optional VLAN insertion. */
> +			tlen = sizeof(dseg->bcount) + dlen;
> +			if (MLX5_TXOFF_CONFIG(VLAN) &&
> +			    loc->mbuf->ol_flags & PKT_TX_VLAN_PKT) {
> +				/*
> +				 * The packet length must be checked in
> +				 * mlx5_tx_able_to_empw() and packet
> +				 * fits into inline length guaranteed.
> +				 */
> +				assert((dlen + sizeof(struct rte_vlan_hdr)) <=
> +					txq->inlen_empw);
> +				tlen += sizeof(struct rte_vlan_hdr);
> +				if (room < tlen)
> +					break;
> +				dseg = mlx5_tx_dseg_vlan(txq, loc, dseg,
> +							 dptr, dlen, olx);
> +#ifdef MLX5_PMD_SOFT_COUNTERS
> +				/* Update sent data bytes counter. */
> +				slen +=	sizeof(struct rte_vlan_hdr);
> +#endif
> +			} else {
> +				if (room < tlen)
> +					break;
> +				dseg = mlx5_tx_dseg_empw(txq, loc, dseg,
> +							 dptr, dlen, olx);
> +			}
> +			tlen = RTE_ALIGN(tlen, MLX5_WSEG_SIZE);
> +			assert(room >= tlen);
> +			room -= tlen;
> +			/*
> +			 * Packet data are completely inlined,
> +			 * free the packet immediately.
> +			 */
> +			rte_pktmbuf_free_seg(loc->mbuf);
> +			goto next_mbuf;
> +pointer_empw:
> +			/*
> +			 * Not inlinable VLAN packets are
> +			 * proceeded outside of this routine.
> +			 */
> +			assert(room >= MLX5_WQE_DSEG_SIZE);
> +			if (MLX5_TXOFF_CONFIG(VLAN))
> +				assert(!(loc->mbuf->ol_flags &
> +					 PKT_TX_VLAN_PKT));
> +			mlx5_tx_dseg_ptr(txq, loc, dseg, dptr, dlen, olx);
> +			/* We have to store mbuf in elts.*/
> +			txq->elts[txq->elts_head++ & txq->elts_m] = loc->mbuf;
> +			room -= MLX5_WQE_DSEG_SIZE;
> +			/* Ring buffer wraparound is checked at the loop end.*/
> +			++dseg;
> +next_mbuf:
> +#ifdef MLX5_PMD_SOFT_COUNTERS
> +			/* Update sent data bytes counter. */
> +			slen += dlen;
> +#endif
> +			loc->pkts_sent++;
> +			loc->elts_free--;
> +			pkts_n--;
> +			if (unlikely(!pkts_n || !loc->elts_free)) {
> +				/*
> +				 * We have no resources/packets to
> +				 * continue build descriptors.
> +				 */
> +				part -= room;
> +				mlx5_tx_idone_empw(txq, loc, part, slen, olx);
> +				return MLX5_TXCMP_CODE_EXIT;
> +			}
> +			/* Check if we have minimal room left. */
> +			if (room < MLX5_WQE_DSEG_SIZE) {
> +				part -= room;
> +				mlx5_tx_idone_empw(txq, loc, part, slen, olx);
> +				goto next_empw;
> +			}
> +			loc->mbuf = *pkts++;
> +			if (likely(pkts_n > 1))
> +				rte_prefetch0(*pkts);
> +			ret = mlx5_tx_able_to_empw(txq, loc, olx, true);
> +			/*
> +			 * Unroll the completion code to avoid
> +			 * returning variable value - it results in
> +			 * unoptimized sequent checking in caller.
> +			 */
> +			if (ret == MLX5_TXCMP_CODE_MULTI) {
> +				part -= room;
> +				mlx5_tx_idone_empw(txq, loc, part, slen, olx);
> +				if (unlikely(!loc->elts_free ||
> +					     !loc->wqe_free))
> +					return MLX5_TXCMP_CODE_EXIT;
> +				return MLX5_TXCMP_CODE_MULTI;
> +			}
> +			if (ret == MLX5_TXCMP_CODE_TSO) {
> +				part -= room;
> +				mlx5_tx_idone_empw(txq, loc, part, slen, olx);
> +				if (unlikely(!loc->elts_free ||
> +					     !loc->wqe_free))
> +					return MLX5_TXCMP_CODE_EXIT;
> +				return MLX5_TXCMP_CODE_TSO;
> +			}
> +			if (ret == MLX5_TXCMP_CODE_SINGLE) {
> +				part -= room;
> +				mlx5_tx_idone_empw(txq, loc, part, slen, olx);
> +				if (unlikely(!loc->elts_free ||
> +					     !loc->wqe_free))
> +					return MLX5_TXCMP_CODE_EXIT;
> +				return MLX5_TXCMP_CODE_SINGLE;
> +			}
> +			if (ret != MLX5_TXCMP_CODE_EMPW) {
> +				assert(false);
> +				part -= room;
> +				mlx5_tx_idone_empw(txq, loc, part, slen, olx);
> +				return MLX5_TXCMP_CODE_ERROR;
> +			}
> +			/*
> +			 * Check whether packet parameters coincide
> +			 * within assumed eMPW batch:
> +			 * - check sum settings
> +			 * - metadata value
> +			 * - software parser settings
> +			 */
> +			if (!mlx5_tx_match_empw(txq, eseg, loc, olx))
> +				break;
> +			/* Packet attributes match, continue the same eMPW. */
> +			if ((uintptr_t)dseg >= (uintptr_t)txq->wqes_end)
> +				dseg = (struct mlx5_wqe_dseg *)txq->wqes;
> +		}
> +		/*
> +		 * We get here to close an existing eMPW
> +		 * session and start the new one.
> +		 */
> +		assert(pkts_n);
> +		part -= room;
> +		if (unlikely(!part))
> +			return MLX5_TXCMP_CODE_EXIT;
> +		mlx5_tx_idone_empw(txq, loc, part, slen, olx);
> +		if (unlikely(!loc->elts_free ||
> +			     !loc->wqe_free))
> +			return MLX5_TXCMP_CODE_EXIT;
> +		goto next_empw;
> +	}
> +	assert(false);
> +}
> +
> +/**
> + * The routine sends packets with ordinary MLX5_OPCODE_SEND.
> + * Data inlining and VLAN insertion are supported.
> + */
> +static __rte_always_inline enum mlx5_txcmp_code
> +mlx5_tx_burst_single_send(struct mlx5_txq_data *restrict txq,
> +			  struct rte_mbuf **restrict pkts,
> +			  unsigned int pkts_n,
> +			  struct mlx5_txq_local *restrict loc,
> +			  unsigned int olx)
> +{
> +	/*
> +	 * Subroutine is the part of mlx5_tx_burst_single()
> +	 * and sends single-segment packet with SEND opcode.
> +	 */
> +	assert(loc->elts_free && loc->wqe_free);
> +	assert(pkts_n > loc->pkts_sent);
> +	pkts += loc->pkts_sent + 1;
> +	pkts_n -= loc->pkts_sent;
> +	for (;;) {
> +		struct mlx5_wqe *restrict wqe;
> +		enum mlx5_txcmp_code ret;
> +
> +		assert(NB_SEGS(loc->mbuf) == 1);
> +		if (MLX5_TXOFF_CONFIG(INLINE)) {
> +			unsigned int inlen, vlan = 0;
> +
> +			inlen = rte_pktmbuf_data_len(loc->mbuf);
> +			if (MLX5_TXOFF_CONFIG(VLAN) &&
> +			    loc->mbuf->ol_flags & PKT_TX_VLAN_PKT) {
> +				vlan = sizeof(struct rte_vlan_hdr);
> +				inlen += vlan;
> +				static_assert((sizeof(struct rte_vlan_hdr) +
> +					       sizeof(struct rte_ether_hdr)) ==
> +					       MLX5_ESEG_MIN_INLINE_SIZE,
> +					       "invalid min inline data size");
> +			}
> +			/*
> +			 * If inlining is enabled at configuration time
> +			 * the limit must be not less than minimal size.
> +			 * Otherwise we would do extra check for data
> +			 * size to avoid crashes due to length overflow.
> +			 */
> +			assert(txq->inlen_send >= MLX5_ESEG_MIN_INLINE_SIZE);
> +			if (inlen <= txq->inlen_send) {
> +				unsigned int seg_n, wqe_n;
> +
> +				rte_prefetch0(rte_pktmbuf_mtod
> +						(loc->mbuf, uint8_t *));
> +				/* Check against minimal length. */
> +				if (inlen <= MLX5_ESEG_MIN_INLINE_SIZE)
> +					return MLX5_TXCMP_CODE_ERROR;
> +				/*
> +				 * Completely inlined packet data WQE:
> +				 * - Control Segment, SEND opcode
> +				 * - Ethernet Segment, no VLAN insertion
> +				 * - Data inlined, VLAN optionally inserted
> +				 * - Alignment to MLX5_WSEG_SIZE
> +				 * Have to estimate amount of WQEBBs
> +				 */
> +				seg_n = (inlen + 3 * MLX5_WSEG_SIZE -
> +					 MLX5_ESEG_MIN_INLINE_SIZE +
> +					 MLX5_WSEG_SIZE - 1) / MLX5_WSEG_SIZE;
> +				/* Check if there are enough WQEBBs. */
> +				wqe_n = (seg_n + 3) / 4;
> +				if (wqe_n > loc->wqe_free)
> +					return MLX5_TXCMP_CODE_EXIT;
> +				wqe = txq->wqes + (txq->wqe_ci & txq->wqe_m);
> +				loc->wqe_last = wqe;
> +				mlx5_tx_cseg_init(txq, loc, wqe, seg_n,
> +						  MLX5_OPCODE_SEND, olx);
> +				mlx5_tx_eseg_data(txq, loc, wqe,
> +						  vlan, inlen, 0, olx);
> +				txq->wqe_ci += wqe_n;
> +				loc->wqe_free -= wqe_n;
> +				/*
> +				 * Packet data are completely inlined,
> +				 * free the packet immediately.
> +				 */
> +				rte_pktmbuf_free_seg(loc->mbuf);
> +			} else if (!MLX5_TXOFF_CONFIG(EMPW) &&
> +				   txq->inlen_mode) {
> +				/*
> +				 * If minimal inlining is requested the eMPW
> +				 * feature should be disabled due to data is
> +				 * inlined into Ethernet Segment, which can
> +				 * not contain inlined data for eMPW due to
> +				 * segment shared for all packets.
> +				 */
> +				struct mlx5_wqe_dseg *restrict dseg;
> +				unsigned int ds;
> +				uint8_t *dptr;
> +
> +				/*
> +				 * The inline-mode settings require
> +				 * to inline the specified amount of
> +				 * data bytes to the Ethernet Segment.
> +				 * We should check the free space in
> +				 * WQE ring buffer to inline partially.
> +				 */
> +				assert(txq->inlen_send >= txq->inlen_mode);
> +				assert(inlen > txq->inlen_mode);
> +				assert(txq->inlen_mode >=
> +						MLX5_ESEG_MIN_INLINE_SIZE);
> +				/*
> +				 * Check whether there are enough free WQEBBs:
> +				 * - Control Segment
> +				 * - Ethernet Segment
> +				 * - First Segment of inlined Ethernet data
> +				 * - ... data continued ...
> +				 * - Finishing Data Segment of pointer type
> +				 */
> +				ds = (MLX5_WQE_CSEG_SIZE +
> +				      MLX5_WQE_ESEG_SIZE +
> +				      MLX5_WQE_DSEG_SIZE +
> +				      txq->inlen_mode -
> +				      MLX5_ESEG_MIN_INLINE_SIZE +
> +				      MLX5_WQE_DSEG_SIZE +
> +				      MLX5_WSEG_SIZE - 1) / MLX5_WSEG_SIZE;
> +				if (loc->wqe_free < ((ds + 3) / 4))
> +					return MLX5_TXCMP_CODE_EXIT;
> +				/*
> +				 * Build the ordinary SEND WQE:
> +				 * - Control Segment
> +				 * - Ethernet Segment, inline inlen_mode bytes
> +				 * - Data Segment of pointer type
> +				 */
> +				wqe = txq->wqes + (txq->wqe_ci & txq->wqe_m);
> +				loc->wqe_last = wqe;
> +				mlx5_tx_cseg_init(txq, loc, wqe, ds,
> +						  MLX5_OPCODE_SEND, olx);
> +				dseg = mlx5_tx_eseg_data(txq, loc, wqe, vlan,
> +							 txq->inlen_mode,
> +							 0, olx);
> +				dptr = rte_pktmbuf_mtod(loc->mbuf, uint8_t *) +
> +				       txq->inlen_mode - vlan;
> +				inlen -= txq->inlen_mode;
> +				mlx5_tx_dseg_ptr(txq, loc, dseg,
> +						 dptr, inlen, olx);
> +				/*
> +				 * WQE is built, update the loop parameters
> +				 * and got to the next packet.
> +				 */
> +				txq->wqe_ci += (ds + 3) / 4;
> +				loc->wqe_free -= (ds + 3) / 4;
> +				/* We have to store mbuf in elts.*/
> +				assert(MLX5_TXOFF_CONFIG(INLINE));
> +				txq->elts[txq->elts_head++ & txq->elts_m] =
> +						loc->mbuf;
> +				--loc->elts_free;
> +			} else {
> +				uint8_t *dptr;
> +				unsigned int dlen;
> +
> +				/*
> +				 * Partially inlined packet data WQE, we have
> +				 * some space in title WQEBB, we can fill it
> +				 * with some packet data. It takes one WQEBB,
> +				 * it is available, no extra space check:
> +				 * - Control Segment, SEND opcode
> +				 * - Ethernet Segment, no VLAN insertion
> +				 * - MLX5_ESEG_MIN_INLINE_SIZE bytes of Data
> +				 * - Data Segment, pointer type
> +				 *
> +				 * We also get here if VLAN insertion is not
> +				 * supported by HW, the inline is enabled.
> +				 */
> +				wqe = txq->wqes + (txq->wqe_ci & txq->wqe_m);
> +				loc->wqe_last = wqe;
> +				mlx5_tx_cseg_init(txq, loc, wqe, 4,
> +						  MLX5_OPCODE_SEND, olx);
> +				mlx5_tx_eseg_dmin(txq, loc, wqe, vlan, olx);
> +				dptr = rte_pktmbuf_mtod(loc->mbuf, uint8_t *) +
> +				       MLX5_ESEG_MIN_INLINE_SIZE - vlan;
> +				/*
> +				 * The length check is performed above, by
> +				 * comparing with txq->inlen_send. We should
> +				 * not get overflow here.
> +				 */
> +				assert(inlen > MLX5_ESEG_MIN_INLINE_SIZE);
> +				dlen = inlen - MLX5_ESEG_MIN_INLINE_SIZE;
> +				mlx5_tx_dseg_ptr(txq, loc, &wqe->dseg[1],
> +						 dptr, dlen, olx);
> +				++txq->wqe_ci;
> +				--loc->wqe_free;
> +				/* We have to store mbuf in elts.*/
> +				assert(MLX5_TXOFF_CONFIG(INLINE));
> +				txq->elts[txq->elts_head++ & txq->elts_m] =
> +						loc->mbuf;
> +				--loc->elts_free;
> +			}
> +#ifdef MLX5_PMD_SOFT_COUNTERS
> +			/* Update sent data bytes counter. */
> +			txq->stats.obytes += vlan +
> +					rte_pktmbuf_data_len(loc->mbuf);
> +#endif
> +		} else {
> +			/*
> +			 * No inline at all, it means the CPU cycles saving
> +			 * is prioritized at configuration, we should not
> +			 * copy any packet data to WQE.
> +			 *
> +			 * SEND WQE, one WQEBB:
> +			 * - Control Segment, SEND opcode
> +			 * - Ethernet Segment, optional VLAN, no inline
> +			 * - Data Segment, pointer type
> +			 */
> +			wqe = txq->wqes + (txq->wqe_ci & txq->wqe_m);
> +			loc->wqe_last = wqe;
> +			mlx5_tx_cseg_init(txq, loc, wqe, 3,
> +					  MLX5_OPCODE_SEND, olx);
> +			mlx5_tx_eseg_none(txq, loc, wqe, olx);
> +			mlx5_tx_dseg_ptr
> +				(txq, loc, &wqe->dseg[0],
> +				 rte_pktmbuf_mtod(loc->mbuf, uint8_t *),
> +				 rte_pktmbuf_data_len(loc->mbuf), olx);
> +			++txq->wqe_ci;
> +			--loc->wqe_free;
> +			/*
> +			 * We should not store mbuf pointer in elts
> +			 * if no inlining is configured, this is done
> +			 * by calling routine in a batch copy.
> +			 */
> +			assert(!MLX5_TXOFF_CONFIG(INLINE));
> +			--loc->elts_free;
> +#ifdef MLX5_PMD_SOFT_COUNTERS
> +			/* Update sent data bytes counter. */
> +			txq->stats.obytes += rte_pktmbuf_data_len(loc->mbuf);
> +			if (MLX5_TXOFF_CONFIG(VLAN) &&
> +			    loc->mbuf->ol_flags & PKT_TX_VLAN_PKT)
> +				txq->stats.obytes +=
> +					sizeof(struct rte_vlan_hdr);
> +#endif
> +		}
> +		++loc->pkts_sent;
> +		--pkts_n;
> +		if (unlikely(!pkts_n || !loc->elts_free || !loc->wqe_free))
> +			return MLX5_TXCMP_CODE_EXIT;
> +		loc->mbuf = *pkts++;
> +		if (pkts_n > 1)
> +			rte_prefetch0(*pkts);
> +		ret = mlx5_tx_able_to_empw(txq, loc, olx, true);
> +		if (unlikely(ret != MLX5_TXCMP_CODE_SINGLE))
> +			return ret;
> +	}
> +	assert(false);
> +}
> +
> +static __rte_always_inline enum mlx5_txcmp_code
> +mlx5_tx_burst_single(struct mlx5_txq_data *restrict txq,
> +		     struct rte_mbuf **restrict pkts,
> +		     unsigned int pkts_n,
> +		     struct mlx5_txq_local *restrict loc,
> +		     unsigned int olx)
> +{
> +	enum mlx5_txcmp_code ret;
> +
> +	ret = mlx5_tx_able_to_empw(txq, loc, olx, false);
> +	if (ret == MLX5_TXCMP_CODE_SINGLE)
> +		goto ordinary_send;
> +	assert(ret == MLX5_TXCMP_CODE_EMPW);
> +	for (;;) {
> +		/* Optimize for inline/no inline eMPW send. */
> +		ret = (MLX5_TXOFF_CONFIG(INLINE)) ?
> +			mlx5_tx_burst_empw_inline
> +				(txq, pkts, pkts_n, loc, olx) :
> +			mlx5_tx_burst_empw_simple
> +				(txq, pkts, pkts_n, loc, olx);
> +		if (ret != MLX5_TXCMP_CODE_SINGLE)
> +			return ret;
> +		/* The resources to send one packet should remain. */
> +		assert(loc->elts_free && loc->wqe_free);
> +ordinary_send:
> +		ret = mlx5_tx_burst_single_send(txq, pkts, pkts_n, loc, olx);
> +		assert(ret != MLX5_TXCMP_CODE_SINGLE);
> +		if (ret != MLX5_TXCMP_CODE_EMPW)
> +			return ret;
> +		/* The resources to send one packet should remain. */
> +		assert(loc->elts_free && loc->wqe_free);
> +	}
> +}
> +
> +/**
> + * DPDK Tx callback template. This is configured template
> + * used to generate routines optimized for specified offload setup.
> + * One of this generated functions is chosen at SQ configuration
> + * time.
> + *
> + * @param txq
> + *   Generic pointer to TX queue structure.
> + * @param[in] pkts
> + *   Packets to transmit.
> + * @param pkts_n
> + *   Number of packets in array.
> + * @param olx
> + *   Configured offloads mask, presents the bits of MLX5_TXOFF_CONFIG_xxx
> + *   values. Should be static to take compile time static configuration
> + *   advantages.
> + *
> + * @return
> + *   Number of packets successfully transmitted (<= pkts_n).
> + */
> +static __rte_always_inline uint16_t
> +mlx5_tx_burst_tmpl(struct mlx5_txq_data *restrict txq,
> +		   struct rte_mbuf **restrict pkts,
> +		   uint16_t pkts_n,
> +		   unsigned int olx)
> +{
> +	struct mlx5_txq_local loc;
> +	enum mlx5_txcmp_code ret;
> +	unsigned int part;
> +
> +	assert(txq->elts_s >= (uint16_t)(txq->elts_head - txq->elts_tail));
> +	assert(txq->wqe_s >= (uint16_t)(txq->wqe_ci - txq->wqe_pi));
> +	/*
> +	 * Check if there are some CQEs, if any:
> +	 * - process an encountered errors
> +	 * - process the completed WQEs
> +	 * - free related mbufs
> +	 * - doorbell the NIC about processed CQEs
> +	 */
> +	if (unlikely(!pkts_n))
> +		return 0;
> +	rte_prefetch0(*pkts);
> +	mlx5_tx_handle_completion(txq, olx);
> +	/*
> +	 * Calculate the number of available resources - elts and WQEs.
> +	 * There are two possible different scenarios:
> +	 * - no data inlining into WQEs, one WQEBB may contains upto
> +	 *   four packets, in this case elts become scarce resource
> +	 * - data inlining into WQEs, one packet may require multiple
> +	 *   WQEBBs, the WQEs become the limiting factor.
> +	 */
> +	assert(txq->elts_s >= (uint16_t)(txq->elts_head - txq->elts_tail));
> +	loc.elts_free = txq->elts_s -
> +				(uint16_t)(txq->elts_head - txq->elts_tail);
> +	assert(txq->wqe_s >= (uint16_t)(txq->wqe_ci - txq->wqe_pi));
> +	loc.wqe_free = txq->wqe_s -
> +				(uint16_t)(txq->wqe_ci - txq->wqe_pi);
> +	if (unlikely(!loc.elts_free || !loc.wqe_free))
> +		return 0;
> +	loc.pkts_sent = 0;
> +	loc.pkts_copy = 0;
> +	loc.wqe_last = NULL;
> +	for (;;) {
> +		/*
> +		 * Fetch the packet from array. Usually this is
> +		 * the first packet in series of multi/single
> +		 * segment packets.
> +		 */
> +		loc.mbuf = *(pkts + loc.pkts_sent);
> +		/* Dedicated branch for multi-segment packets. */
> +		if (MLX5_TXOFF_CONFIG(MULTI) &&
> +		    unlikely(NB_SEGS(loc.mbuf) > 1)) {
> +			/*
> +			 * Multi-segment packet encountered.
> +			 * Hardware is able to process it only
> +			 * with SEND/TSO opcodes, one packet
> +			 * per WQE, do it in dedicated routine.
> +			 */
> +enter_send_multi:
> +			assert(loc.pkts_sent >= loc.pkts_copy);
> +			part = loc.pkts_sent - loc.pkts_copy;
> +			if (!MLX5_TXOFF_CONFIG(INLINE) && part) {
> +				/*
> +				 * There are some single-segment mbufs not
> +				 * stored in elts. The mbufs must be in the
> +				 * same order as WQEs, so we must copy the
> +				 * mbufs to elts here, before the coming
> +				 * multi-segment packet mbufs is appended.
> +				 */
> +				mlx5_tx_copy_elts(txq, pkts + loc.pkts_copy,
> +						  part, olx);
> +				loc.pkts_copy = loc.pkts_sent;
> +			}
> +			assert(pkts_n > loc.pkts_sent);
> +			ret = mlx5_tx_burst_mseg(txq, pkts, pkts_n, &loc, olx);
> +			if (!MLX5_TXOFF_CONFIG(INLINE))
> +				loc.pkts_copy = loc.pkts_sent;
> +			/*
> +			 * These returned code checks are supposed
> +			 * to be optimized out due to routine inlining.
> +			 */
> +			if (ret == MLX5_TXCMP_CODE_EXIT) {
> +				/*
> +				 * The routine returns this code when
> +				 * all packets are sent or there is no
> +				 * enough resources to complete request.
> +				 */
> +				break;
> +			}
> +			if (ret == MLX5_TXCMP_CODE_ERROR) {
> +				/*
> +				 * The routine returns this code when
> +				 * some error in the incoming packets
> +				 * format occurred.
> +				 */
> +				txq->stats.oerrors++;
> +				break;
> +			}
> +			if (ret == MLX5_TXCMP_CODE_SINGLE) {
> +				/*
> +				 * The single-segment packet was encountered
> +				 * in the array, try to send it with the
> +				 * best optimized way, possible engaging eMPW.
> +				 */
> +				goto enter_send_single;
> +			}
> +			if (MLX5_TXOFF_CONFIG(TSO) &&
> +			    ret == MLX5_TXCMP_CODE_TSO) {
> +				/*
> +				 * The single-segment TSO packet was
> +				 * encountered in the array.
> +				 */
> +				goto enter_send_tso;
> +			}
> +			/* We must not get here. Something is going wrong. */
> +			assert(false);
> +			txq->stats.oerrors++;
> +			break;
> +		}
> +		/* Dedicated branch for single-segment TSO packets. */
> +		if (MLX5_TXOFF_CONFIG(TSO) &&
> +		    unlikely(loc.mbuf->ol_flags & PKT_TX_TCP_SEG)) {
> +			/*
> +			 * TSO might require special way for inlining
> +			 * (dedicated parameters) and is sent with
> +			 * MLX5_OPCODE_TSO opcode only, provide this
> +			 * in dedicated branch.
> +			 */
> +enter_send_tso:
> +			assert(NB_SEGS(loc.mbuf) == 1);
> +			assert(pkts_n > loc.pkts_sent);
> +			ret = mlx5_tx_burst_tso(txq, pkts, pkts_n, &loc, olx);
> +			/*
> +			 * These returned code checks are supposed
> +			 * to be optimized out due to routine inlining.
> +			 */
> +			if (ret == MLX5_TXCMP_CODE_EXIT)
> +				break;
> +			if (ret == MLX5_TXCMP_CODE_ERROR) {
> +				txq->stats.oerrors++;
> +				break;
> +			}
> +			if (ret == MLX5_TXCMP_CODE_SINGLE)
> +				goto enter_send_single;
> +			if (MLX5_TXOFF_CONFIG(MULTI) &&
> +			    ret == MLX5_TXCMP_CODE_MULTI) {
> +				/*
> +				 * The multi-segment packet was
> +				 * encountered in the array.
> +				 */
> +				goto enter_send_multi;
> +			}
> +			/* We must not get here. Something is going wrong. */
> +			assert(false);
> +			txq->stats.oerrors++;
> +			break;
> +		}
> +		/*
> +		 * The dedicated branch for the single-segment packets
> +		 * without TSO. Often these ones can be sent using
> +		 * MLX5_OPCODE_EMPW with multiple packets in one WQE.
> +		 * The routine builds the WQEs till it encounters
> +		 * the TSO or multi-segment packet (in case if these
> +		 * offloads are requested at SQ configuration time).
> +		 */
> +enter_send_single:
> +		assert(pkts_n > loc.pkts_sent);
> +		ret = mlx5_tx_burst_single(txq, pkts, pkts_n, &loc, olx);
> +		/*
> +		 * These returned code checks are supposed
> +		 * to be optimized out due to routine inlining.
> +		 */
> +		if (ret == MLX5_TXCMP_CODE_EXIT)
> +			break;
> +		if (ret == MLX5_TXCMP_CODE_ERROR) {
> +			txq->stats.oerrors++;
> +			break;
> +		}
> +		if (MLX5_TXOFF_CONFIG(MULTI) &&
> +		    ret == MLX5_TXCMP_CODE_MULTI) {
> +			/*
> +			 * The multi-segment packet was
> +			 * encountered in the array.
> +			 */
> +			goto enter_send_multi;
> +		}
> +		if (MLX5_TXOFF_CONFIG(TSO) &&
> +		    ret == MLX5_TXCMP_CODE_TSO) {
> +			/*
> +			 * The single-segment TSO packet was
> +			 * encountered in the array.
> +			 */
> +			goto enter_send_tso;
> +		}
> +		/* We must not get here. Something is going wrong. */
> +		assert(false);
> +		txq->stats.oerrors++;
> +		break;
> +	}
> +	/*
> +	 * Main Tx loop is completed, do the rest:
> +	 * - set completion request if thresholds are reached
> +	 * - doorbell the hardware
> +	 * - copy the rest of mbufs to elts (if any)
> +	 */
> +	assert(MLX5_TXOFF_CONFIG(INLINE) || loc.pkts_sent >= loc.pkts_copy);
> +	/* Take a shortcut if nothing is sent. */
> +	if (unlikely(loc.pkts_sent == 0))
> +		return 0;
> +	/* Not all of the mbufs may be stored into elts yet. */
> +	part = MLX5_TXOFF_CONFIG(INLINE) ? 0 : loc.pkts_sent - loc.pkts_copy;
> +	mlx5_tx_request_completion(txq, part, &loc, olx);
> +	/*
> +	 * Ring QP doorbell immediately after WQE building completion
> +	 * to improve latencies. The pure software related data treatment
> +	 * can be completed after doorbell. Tx CQEs for this SQ are
> +	 * processed in this thread only by the polling.
> +	 */
> +	mlx5_tx_dbrec_cond_wmb(txq, loc.wqe_last, 0);
> +	if (!MLX5_TXOFF_CONFIG(INLINE) && part) {
> +		/*
> +		 * There are some single-segment mbufs not stored in elts.
> +		 * It can be only if last packet was single-segment.
> +		 * The copying is gathered into one place due to it is
> +		 * a good opportunity to optimize that with SIMD.
> +		 * Unfortunately if inlining is enabled the gaps in
> +		 * pointer array may happen due to early freeing of the
> +		 * inlined mbufs.
> +		 */
> +		mlx5_tx_copy_elts(txq, pkts + loc.pkts_copy, part, olx);
> +	}
> +#ifdef MLX5_PMD_SOFT_COUNTERS
> +	/* Increment sent packets counter. */
> +	txq->stats.opackets += loc.pkts_sent;
> +#endif
> +	assert(txq->elts_s >= (uint16_t)(txq->elts_head - txq->elts_tail));
> +	assert(txq->wqe_s >= (uint16_t)(txq->wqe_ci - txq->wqe_pi));
> +	return loc.pkts_sent;
> }
> 
> /* Generate routines with Enhanced Multi-Packet Write support. */
> diff --git a/drivers/net/mlx5/mlx5_rxtx.h b/drivers/net/mlx5/mlx5_rxtx.h
> index 03ddd9e..bc8a61a 100644
> --- a/drivers/net/mlx5/mlx5_rxtx.h
> +++ b/drivers/net/mlx5/mlx5_rxtx.h
> @@ -355,8 +355,9 @@ struct mlx5_txq_ctrl *mlx5_txq_new(struct rte_eth_dev *dev, uint16_t idx,
> void mlx5_set_ptype_table(void);
> void mlx5_set_cksum_table(void);
> void mlx5_set_swp_types_table(void);
> -__rte_noinline uint16_t mlx5_tx_error_cqe_handle(struct mlx5_txq_data *txq,
> -					volatile struct mlx5_err_cqe *err_cqe);
> +__rte_noinline uint16_t mlx5_tx_error_cqe_handle
> +				(struct mlx5_txq_data *restrict txq,
> +				 volatile struct mlx5_err_cqe *err_cqe);
> uint16_t mlx5_rx_burst(void *dpdk_rxq, struct rte_mbuf **pkts, uint16_t pkts_n);
> void mlx5_rxq_initialize(struct mlx5_rxq_data *rxq);
> __rte_noinline int mlx5_rx_err_handle(struct mlx5_rxq_data *rxq,
> -- 
> 1.8.3.1
>