RE: [PATCH v3 07/36] net/ice: refactor context descriptor handling

Loftus, Ciara
2026-02-06T10:47:17Z

> Subject: [PATCH v3 07/36] net/ice: refactor context descriptor handling
>
> Create a single function to manage all context descriptor handling,
> which returns either 0 or 1 depending on whether a descriptor is needed
> or not, as well as returning directly the descriptor contents if
> relevant.
>
> Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
> ---
> drivers/net/intel/ice/ice_rxtx.c | 104 +++++++++++++++++--------------
> 1 file changed, 57 insertions(+), 47 deletions(-)
>
> diff --git a/drivers/net/intel/ice/ice_rxtx.c b/drivers/net/intel/ice/ice_rxtx.c
> index 2a53b614b2..cc442fed75 100644
> --- a/drivers/net/intel/ice/ice_rxtx.c
> +++ b/drivers/net/intel/ice/ice_rxtx.c
> @@ -2966,10 +2966,6 @@ ice_txd_enable_checksum(uint64_t ol_flags,
> uint32_t *td_offset,
> union ci_tx_offload tx_offload)
> {
> - /* Set MACLEN */
> - if (!(ol_flags & RTE_MBUF_F_TX_TUNNEL_MASK))
> - *td_offset |= (tx_offload.l2_len >> 1)
> - << CI_TX_DESC_LEN_MACLEN_S;
>
> /* Enable L3 checksum offloads */
> if (ol_flags & RTE_MBUF_F_TX_IP_CKSUM) {
> @@ -3052,7 +3048,7 @@ ice_calc_context_desc(uint64_t flags)
>
> /* set ice TSO context descriptor */
> static inline uint64_t
> -ice_set_tso_ctx(struct rte_mbuf *mbuf, union ci_tx_offload tx_offload)
> +ice_set_tso_ctx(uint64_t ol_flags, const struct rte_mbuf *mbuf, union
> ci_tx_offload tx_offload)
> {
> uint64_t ctx_desc = 0;
> uint32_t cd_cmd, hdr_len, cd_tso_len;
> @@ -3063,7 +3059,7 @@ ice_set_tso_ctx(struct rte_mbuf *mbuf, union
> ci_tx_offload tx_offload)
> }
>
> hdr_len = tx_offload.l2_len + tx_offload.l3_len + tx_offload.l4_len;
> - hdr_len += (mbuf->ol_flags & RTE_MBUF_F_TX_TUNNEL_MASK) ?
> + hdr_len += (ol_flags & RTE_MBUF_F_TX_TUNNEL_MASK) ?
> tx_offload.outer_l2_len + tx_offload.outer_l3_len : 0;
>
> cd_cmd = CI_TX_CTX_DESC_TSO;
> @@ -3075,6 +3071,49 @@ ice_set_tso_ctx(struct rte_mbuf *mbuf, union
> ci_tx_offload tx_offload)
> return ctx_desc;
> }
>
> +/* compute a context descriptor if one is necessary based on the ol_flags
> + *
> + * Returns 0 if no descriptor is necessary.
> + * Returns 1 if one is necessary and the contents of the descriptor are
> returned
> + * in the values pointed to by qw0 and qw1. td_offset may also be modified.

Regarding the comment above, "td_offset" is not a variable in this function, I
assume the comment is obsolete.

> + */
> +static __rte_always_inline uint16_t
> +get_context_desc(uint64_t ol_flags, const struct rte_mbuf *tx_pkt,
> + const union ci_tx_offload *tx_offload, const struct ci_tx_queue *txq,
> + uint64_t *qw0, uint64_t *qw1)
> +{
> + uint16_t cd_l2tag2 = 0;
> + uint64_t cd_type_cmd_tso_mss = ICE_TX_DESC_DTYPE_CTX;
> + uint32_t cd_tunneling_params = 0;
> + uint64_t ptp_tx_index = txq->ice_vsi->adapter->ptp_tx_index;
> +
> + if (ice_calc_context_desc(ol_flags) == 0)
> + return 0;
> +
> + if (ol_flags & RTE_MBUF_F_TX_TUNNEL_MASK)
> + ice_parse_tunneling_params(ol_flags, *tx_offload,
> &cd_tunneling_params);
> +
> + if (ol_flags & (RTE_MBUF_F_TX_TCP_SEG |
> RTE_MBUF_F_TX_UDP_SEG))
> + cd_type_cmd_tso_mss |= ice_set_tso_ctx(ol_flags, tx_pkt,
> *tx_offload);
> + else if (ol_flags & RTE_MBUF_F_TX_IEEE1588_TMST)
> + cd_type_cmd_tso_mss |=
> + ((uint64_t)CI_TX_CTX_DESC_TSYN <<
> CI_TXD_QW1_CMD_S) |
> + ((ptp_tx_index << ICE_TXD_CTX_QW1_TSYN_S) &
> ICE_TXD_CTX_QW1_TSYN_M);
> +
> +
> + /* TX context descriptor based double VLAN insert */
> + if (ol_flags & RTE_MBUF_F_TX_QINQ) {
> + cd_l2tag2 = tx_pkt->vlan_tci_outer;
> + cd_type_cmd_tso_mss |=
> ((uint64_t)CI_TX_CTX_DESC_IL2TAG2 << CI_TXD_QW1_CMD_S);
> + }
> +
> + *qw0 = rte_cpu_to_le_32(cd_tunneling_params) |
> + ((uint64_t)rte_cpu_to_le_16(cd_l2tag2) << 32);
> + *qw1 = rte_cpu_to_le_64(cd_type_cmd_tso_mss);
> +
> + return 1;
> +}
> +
> uint16_t
> ice_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts, uint16_t nb_pkts)
> {
> @@ -3085,7 +3124,6 @@ ice_xmit_pkts(void *tx_queue, struct rte_mbuf
> **tx_pkts, uint16_t nb_pkts)
> struct ci_tx_entry *txe, *txn;
> struct rte_mbuf *tx_pkt;
> struct rte_mbuf *m_seg;
> - uint32_t cd_tunneling_params;
> uint16_t tx_id;
> uint16_t ts_id = -1;
> uint16_t nb_tx;
> @@ -3096,6 +3134,7 @@ ice_xmit_pkts(void *tx_queue, struct rte_mbuf
> **tx_pkts, uint16_t nb_pkts)
> uint32_t td_tag = 0;
> uint16_t tx_last;
> uint16_t slen;
> + uint16_t l2_len;
> uint64_t buf_dma_addr;
> uint64_t ol_flags;
> union ci_tx_offload tx_offload = {0};
> @@ -3114,20 +3153,25 @@ ice_xmit_pkts(void *tx_queue, struct rte_mbuf
> **tx_pkts, uint16_t nb_pkts)
> (void)ci_tx_xmit_cleanup(txq);
>
> for (nb_tx = 0; nb_tx < nb_pkts; nb_tx++) {
> + uint64_t cd_qw0, cd_qw1;
> tx_pkt = *tx_pkts++;
>
> + ol_flags = tx_pkt->ol_flags;
> td_cmd = 0;
> td_tag = 0;
> - td_offset = 0;
> - ol_flags = tx_pkt->ol_flags;
> + l2_len = ol_flags & RTE_MBUF_F_TX_TUNNEL_MASK ?
> + tx_pkt->outer_l2_len : tx_pkt->l2_len;
> + td_offset = (l2_len >> 1) << CI_TX_DESC_LEN_MACLEN_S;
> +
> tx_offload.l2_len = tx_pkt->l2_len;
> tx_offload.l3_len = tx_pkt->l3_len;
> tx_offload.outer_l2_len = tx_pkt->outer_l2_len;
> tx_offload.outer_l3_len = tx_pkt->outer_l3_len;
> 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 = ice_calc_context_desc(ol_flags);
> + nb_ctx = get_context_desc(ol_flags, tx_pkt, &tx_offload, txq,
> &cd_qw0, &cd_qw1);
>
> /* The number of descriptors that must be allocated for
> * a packet equals to the number of the segments of that
> @@ -3169,15 +3213,6 @@ ice_xmit_pkts(void *tx_queue, struct rte_mbuf
> **tx_pkts, uint16_t nb_pkts)
> td_tag = tx_pkt->vlan_tci;
> }
>
> - /* Fill in tunneling parameters if necessary */
> - cd_tunneling_params = 0;
> - if (ol_flags & RTE_MBUF_F_TX_TUNNEL_MASK) {
> - td_offset |= (tx_offload.outer_l2_len >> 1)
> - << CI_TX_DESC_LEN_MACLEN_S;
> - ice_parse_tunneling_params(ol_flags, tx_offload,
> - &cd_tunneling_params);
> - }
> -
> /* Enable checksum offloading */
> if (ol_flags & ICE_TX_CKSUM_OFFLOAD_MASK)
> ice_txd_enable_checksum(ol_flags, &td_cmd,
> @@ -3185,11 +3220,7 @@ ice_xmit_pkts(void *tx_queue, struct rte_mbuf
> **tx_pkts, uint16_t nb_pkts)
>
> if (nb_ctx) {
> /* Setup TX context descriptor if required */
> - volatile struct ice_tx_ctx_desc *ctx_txd =
> - (volatile struct ice_tx_ctx_desc *)
> - &ci_tx_ring[tx_id];
> - uint16_t cd_l2tag2 = 0;
> - uint64_t cd_type_cmd_tso_mss =
> ICE_TX_DESC_DTYPE_CTX;
> + uint64_t *ctx_txd = RTE_CAST_PTR(uint64_t *,
> &ci_tx_ring[tx_id]);
>
> txn = &sw_ring[txe->next_id];
> RTE_MBUF_PREFETCH_TO_FREE(txn->mbuf);
> @@ -3198,29 +3229,8 @@ ice_xmit_pkts(void *tx_queue, struct rte_mbuf
> **tx_pkts, uint16_t nb_pkts)
> txe->mbuf = NULL;
> }
>
> - if (ol_flags & (RTE_MBUF_F_TX_TCP_SEG |
> RTE_MBUF_F_TX_UDP_SEG))
> - cd_type_cmd_tso_mss |=
> - ice_set_tso_ctx(tx_pkt, tx_offload);
> - else if (ol_flags & RTE_MBUF_F_TX_IEEE1588_TMST)
> - cd_type_cmd_tso_mss |=
> - ((uint64_t)CI_TX_CTX_DESC_TSYN <<
> - CI_TXD_QW1_CMD_S) |
> - (((uint64_t)txq->ice_vsi->adapter-
> >ptp_tx_index <<
> - ICE_TXD_CTX_QW1_TSYN_S) &
> ICE_TXD_CTX_QW1_TSYN_M);
> -
> - ctx_txd->tunneling_params =
> - rte_cpu_to_le_32(cd_tunneling_params);
> -
> - /* TX context descriptor based double VLAN insert */
> - if (ol_flags & RTE_MBUF_F_TX_QINQ) {
> - cd_l2tag2 = tx_pkt->vlan_tci_outer;
> - cd_type_cmd_tso_mss |=
> - ((uint64_t)CI_TX_CTX_DESC_IL2TAG2
> <<
> - CI_TXD_QW1_CMD_S);
> - }
> - ctx_txd->l2tag2 = rte_cpu_to_le_16(cd_l2tag2);
> - ctx_txd->qw1 =
> - rte_cpu_to_le_64(cd_type_cmd_tso_mss);
> + ctx_txd[0] = cd_qw0;
> + ctx_txd[1] = cd_qw1;
>
> txe->last_id = tx_last;
> tx_id = txe->next_id;
> --
> 2.51.0