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

Burakov, Anatoly
2026-02-10T12:52:18Z

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@intel.com>
> Acked-by: Ciara Loftus <ciara.loftus@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@intel.com>

--
Thanks,
Anatoly