[PATCH v4 08/35] net/idpf: refactor context descriptor handling

[Burakov, Anatoly]

On 2/9/2026 5:45 PM, Bruce Richardson wrote:
> Move all context descriptor handling to a single function, as with the
> ice and i40e drivers.
> 
> Signed-off-by: Bruce Richardson <bruce.richardson at intel.com>
> Acked-by: Ciara Loftus <ciara.loftus at intel.com>
> ---
>   drivers/net/intel/idpf/idpf_common_rxtx.c | 61 +++++++++++------------
>   1 file changed, 28 insertions(+), 33 deletions(-)
> 
> diff --git a/drivers/net/intel/idpf/idpf_common_rxtx.c b/drivers/net/intel/idpf/idpf_common_rxtx.c
> index 11d6848430..9219ad9047 100644
> --- a/drivers/net/intel/idpf/idpf_common_rxtx.c
> +++ b/drivers/net/intel/idpf/idpf_common_rxtx.c
> @@ -845,37 +845,36 @@ idpf_calc_context_desc(uint64_t flags)
>   	return 0;
>   }
>   
> -/* set TSO context descriptor
> +/* set TSO context descriptor, returns 0 if no context needed, 1 if context set
>    */
> -static inline void
> -idpf_set_splitq_tso_ctx(struct rte_mbuf *mbuf,
> +static inline uint16_t
> +idpf_set_tso_ctx(uint64_t ol_flags, struct rte_mbuf *mbuf,
>   			union ci_tx_offload tx_offload,
> -			volatile union idpf_flex_tx_ctx_desc *ctx_desc)
> +			uint64_t *qw0, uint64_t *qw1)
>   {
> -	uint16_t cmd_dtype;
> +	uint16_t cmd_dtype = IDPF_TX_DESC_DTYPE_FLEX_TSO_CTX | IDPF_TX_FLEX_CTX_DESC_CMD_TSO;
> +	uint16_t tso_segsz = mbuf->tso_segsz;
>   	uint32_t tso_len;
>   	uint8_t hdr_len;
>   
> +	if (idpf_calc_context_desc(ol_flags) == 0)
> +		return 0;
> +
> +	/* TSO context descriptor setup */
>   	if (tx_offload.l4_len == 0) {
>   		TX_LOG(DEBUG, "L4 length set to 0");
> -		return;
> +		return 0;
>   	}
>   
> -	hdr_len = tx_offload.l2_len +
> -		tx_offload.l3_len +
> -		tx_offload.l4_len;
> -	cmd_dtype = IDPF_TX_DESC_DTYPE_FLEX_TSO_CTX |
> -		IDPF_TX_FLEX_CTX_DESC_CMD_TSO;
> +	hdr_len = tx_offload.l2_len + tx_offload.l3_len + tx_offload.l4_len;
>   	tso_len = mbuf->pkt_len - hdr_len;
>   
> -	ctx_desc->tso.qw1.cmd_dtype = rte_cpu_to_le_16(cmd_dtype);
> -	ctx_desc->tso.qw0.hdr_len = hdr_len;
> -	ctx_desc->tso.qw0.mss_rt =
> -		rte_cpu_to_le_16((uint16_t)mbuf->tso_segsz &
> -				 IDPF_TXD_FLEX_CTX_MSS_RT_M);
> -	ctx_desc->tso.qw0.flex_tlen =
> -		rte_cpu_to_le_32(tso_len &
> -				 IDPF_TXD_FLEX_CTX_MSS_RT_M);
> +	*qw0 = rte_cpu_to_le_32(tso_len & IDPF_TXD_FLEX_CTX_MSS_RT_M) |
> +	       ((uint64_t)rte_cpu_to_le_16(tso_segsz & IDPF_TXD_FLEX_CTX_MSS_RT_M) << 32) |
> +	       ((uint64_t)hdr_len << 48);
> +	*qw1 = rte_cpu_to_le_16(cmd_dtype);
> +
> +	return 1;
>   }
>   
>   RTE_EXPORT_INTERNAL_SYMBOL(idpf_dp_splitq_xmit_pkts)
> @@ -933,7 +932,8 @@ idpf_dp_splitq_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
>   		tx_offload.l4_len = tx_pkt->l4_len;
>   		tx_offload.tso_segsz = tx_pkt->tso_segsz;
>   		/* Calculate the number of context descriptors needed. */
> -		nb_ctx = idpf_calc_context_desc(ol_flags);
> +		uint64_t cd_qw0, cd_qw1;
> +		nb_ctx = idpf_set_tso_ctx(ol_flags, tx_pkt, tx_offload, &cd_qw0, &cd_qw1);
>   
>   		/* Calculate the number of TX descriptors needed for
>   		 * each packet. For TSO packets, use ci_calc_pkt_desc as
> @@ -950,12 +950,10 @@ idpf_dp_splitq_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
>   
>   		/* context descriptor */
>   		if (nb_ctx != 0) {
> -			volatile union idpf_flex_tx_ctx_desc *ctx_desc =
> -				(volatile union idpf_flex_tx_ctx_desc *)&txr[tx_id];
> +			uint64_t *ctx_desc = RTE_CAST_PTR(uint64_t *, &txr[tx_id]);
>   
> -			if ((ol_flags & RTE_MBUF_F_TX_TCP_SEG) != 0)
> -				idpf_set_splitq_tso_ctx(tx_pkt, tx_offload,
> -							ctx_desc);
> +			ctx_desc[0] = cd_qw0;
> +			ctx_desc[1] = cd_qw1;
>   
>   			tx_id++;
>   			if (tx_id == txq->nb_tx_desc)
> @@ -1388,7 +1386,8 @@ idpf_dp_singleq_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
>   		tx_offload.l4_len = tx_pkt->l4_len;
>   		tx_offload.tso_segsz = tx_pkt->tso_segsz;
>   		/* Calculate the number of context descriptors needed. */
> -		nb_ctx = idpf_calc_context_desc(ol_flags);
> +		uint64_t cd_qw0, cd_qw1;
> +		nb_ctx = idpf_set_tso_ctx(ol_flags, tx_pkt, tx_offload, &cd_qw0, &cd_qw1);
>   
>   		/* The number of descriptors that must be allocated for
>   		 * a packet. For TSO packets, use ci_calc_pkt_desc as
> @@ -1431,9 +1430,7 @@ idpf_dp_singleq_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
>   
>   		if (nb_ctx != 0) {
>   			/* Setup TX context descriptor if required */
> -			volatile union idpf_flex_tx_ctx_desc *ctx_txd =
> -				(volatile union idpf_flex_tx_ctx_desc *)
> -				&txr[tx_id];
> +			uint64_t *ctx_txd = RTE_CAST_PTR(uint64_t *, &txr[tx_id]);
>   
>   			txn = &sw_ring[txe->next_id];
>   			RTE_MBUF_PREFETCH_TO_FREE(txn->mbuf);
> @@ -1442,10 +1439,8 @@ idpf_dp_singleq_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
>   				txe->mbuf = NULL;
>   			}
>   
> -			/* TSO enabled */
> -			if ((ol_flags & RTE_MBUF_F_TX_TCP_SEG) != 0)
> -				idpf_set_splitq_tso_ctx(tx_pkt, tx_offload,
> -							ctx_txd);
> +			ctx_txd[0] = cd_qw0;
> +			ctx_txd[1] = cd_qw1;
>   
>   			txe->last_id = tx_last;
>   			tx_id = txe->next_id;

Yay type safety! :D Gotta love C

Acked-by: Anatoly Burakov <anatoly.burakov at intel.com>

-- 
Thanks,
Anatoly