[dpdk-dev] [PATCH v2] net/i40e: add Tx preparation for simple Tx data path

[Ananyev, Konstantin]

Hi Leyi,

> Introduce i40e_simple_prep_pkts() as the preparation function for
> simple Tx data path, as it's for sanity check for simple Tx.
> 
> Suggested-by: Konstantin Ananyev <konstantin.ananyev at intel.com>
> Signed-off-by: Leyi Rong <leyi.rong at intel.com>
> ---
>  drivers/net/i40e/i40e_rxtx.c | 42 +++++++++++++++++++++++++++++++++++-
>  drivers/net/i40e/i40e_rxtx.h |  2 ++
>  2 files changed, 43 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/i40e/i40e_rxtx.c b/drivers/net/i40e/i40e_rxtx.c
> index 3c7686c3f4..282eb5924b 100644
> --- a/drivers/net/i40e/i40e_rxtx.c
> +++ b/drivers/net/i40e/i40e_rxtx.c
> @@ -1479,6 +1479,46 @@ i40e_xmit_pkts_vec(void *tx_queue, struct rte_mbuf **tx_pkts,
>  	return nb_tx;
>  }
> 
> +/*********************************************************************
> + *
> + *  TX simple prep functions
> + *
> + **********************************************************************/
> +uint16_t
> +i40e_simple_prep_pkts(__rte_unused void *tx_queue, struct rte_mbuf **tx_pkts,
> +		      uint16_t nb_pkts)
> +{
> +	int i;
> +	uint64_t ol_flags;
> +	struct rte_mbuf *m;
> +	struct i40e_tx_queue *txq = (struct i40e_tx_queue *)tx_queue;
> +
> +	for (i = 0; i < nb_pkts; i++) {
> +		m = tx_pkts[i];
> +		ol_flags = m->ol_flags;
> +
> +		if (!(txq->offloads ==
> +			(txq->offloads & DEV_TX_OFFLOAD_MBUF_FAST_FREE) &&
> +			m->nb_segs == 1)) {

I think we don't need to check  txq->offloads here,
they should be already checked at setup phase.
I suppose:
if (m->nb_segs != 1) {...}
should be enough here. 

> +			rte_errno = EINVAL;
> +			return i;
> +		}
> +
> +		if (ol_flags & I40E_TX_OFFLOAD_NOTSUP_MASK) {

It would return OK for the packet with any supported by any i40e TX offload (full-featured path).
Probably we need here instead:
if (ol_flags & PKT_TX_OFFLOAD_MASK)  {...}

> +			rte_errno = ENOTSUP;
> +			return i;
> +		}
> +
> +		/* check the size of packet */
> +		if (m->pkt_len < I40E_TX_MIN_PKT_LEN ||
> +		    m->pkt_len > I40E_FRAME_SIZE_MAX) {
> +			rte_errno = EINVAL;
> +			return i;
> +		}
> +	}
> +	return i;
> +}
> +
>  /*********************************************************************
>   *
>   *  TX prep functions
> @@ -3412,7 +3452,7 @@ i40e_set_tx_function(struct rte_eth_dev *dev)
>  			PMD_INIT_LOG(DEBUG, "Simple tx finally be used.");
>  			dev->tx_pkt_burst = i40e_xmit_pkts_simple;
>  		}
> -		dev->tx_pkt_prepare = NULL;
> +		dev->tx_pkt_prepare = i40e_simple_prep_pkts;
>  	} else {
>  		PMD_INIT_LOG(DEBUG, "Xmit tx finally be used.");
>  		dev->tx_pkt_burst = i40e_xmit_pkts;
> diff --git a/drivers/net/i40e/i40e_rxtx.h b/drivers/net/i40e/i40e_rxtx.h
> index 3447a58c82..5ccf5773e8 100644
> --- a/drivers/net/i40e/i40e_rxtx.h
> +++ b/drivers/net/i40e/i40e_rxtx.h
> @@ -208,6 +208,8 @@ uint16_t i40e_recv_scattered_pkts(void *rx_queue,
>  uint16_t i40e_xmit_pkts(void *tx_queue,
>  			struct rte_mbuf **tx_pkts,
>  			uint16_t nb_pkts);
> +uint16_t i40e_simple_prep_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
> +			       uint16_t nb_pkts);
>  uint16_t i40e_prep_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
>  		uint16_t nb_pkts);
>  int i40e_tx_queue_init(struct i40e_tx_queue *txq);
> --
> 2.17.1