[RFC PATCH 09/27] net/idpf: refactor context descriptor handling

Bruce Richardson
2025-12-19T17:27:20Z

move all context descriptor handling to a single function, as with the
ice driver.

Signed-off-by: Bruce Richardson <bruce.richardson@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;
--
2.51.0