[PATCH 07/13] net/intel: use function callback for lldp

Bruce Richardson bruce.richardson at intel.com
Thu Sep 3 19:01:36 CEST 2026


Limit LLDP support for iavf drivers for now, by using a callback to
handle its processing. Drivers not supporting this pass a NULL pointer
and the compiler will optimize away the branches. For iavf, the compiler
can inline the subfunction directly as it's known at compile-time.

Signed-off-by: Bruce Richardson <bruce.richardson at intel.com>
---
 drivers/net/intel/common/tx_vec_x86.h         | 42 +++++++++++--------
 drivers/net/intel/iavf/iavf_rxtx_vec_avx2.c   | 16 +++++--
 drivers/net/intel/iavf/iavf_rxtx_vec_avx512.c | 17 +++++---
 3 files changed, 48 insertions(+), 27 deletions(-)

diff --git a/drivers/net/intel/common/tx_vec_x86.h b/drivers/net/intel/common/tx_vec_x86.h
index b65bc9fc78..f769765cba 100644
--- a/drivers/net/intel/common/tx_vec_x86.h
+++ b/drivers/net/intel/common/tx_vec_x86.h
@@ -11,6 +11,12 @@
 
 #include "tx.h"
 
+/* Optional per-driver LLDP switch-uplink check for ctx descriptors.
+ * Takes the ctx-desc high qword and returns it with the LLDP bit applied
+ * if appropriate. NULL disables the check.
+ */
+typedef uint64_t (*ci_tx_ctx_lldp_fn)(struct rte_mbuf *pkt, uint64_t high_ctx_qw);
+
 static __rte_always_inline void
 ci_fill_ctx_desc_tunneling(uint64_t *low_ctx_qw, struct rte_mbuf *pkt)
 {
@@ -228,7 +234,7 @@ ci_vtx_avx2(volatile struct ci_tx_desc *txdp,
 static __rte_always_inline void
 ci_vtx1_ctx_avx2(volatile struct ci_tx_desc *txdp, struct rte_mbuf *pkt,
 		uint64_t flags, bool offload, enum ci_l2tag_pos single_vlan_pos,
-		enum ci_l2tag_pos qinq_outer_pos, bool ptype_lldp_enabled)
+		enum ci_l2tag_pos qinq_outer_pos, ci_tx_ctx_lldp_fn lldp_check)
 {
 	uint64_t high_ctx_qw = CI_TX_DESC_DTYPE_CTX;
 	uint64_t low_ctx_qw = 0;
@@ -247,8 +253,8 @@ ci_vtx1_ctx_avx2(volatile struct ci_tx_desc *txdp, struct rte_mbuf *pkt,
 			low_ctx_qw |= (uint64_t)pkt->vlan_tci << CI_TXD_CTX_QW0_L2TAG2_S;
 		}
 	}
-	if (IAVF_CHECK_TX_LLDP(pkt, ptype_lldp_enabled))
-		high_ctx_qw |= IAVF_TX_CTX_DESC_SWTCH_UPLINK << CI_TXD_QW1_CMD_S;
+	if (lldp_check != NULL)
+		high_ctx_qw = lldp_check(pkt, high_ctx_qw);
 	uint64_t high_data_qw = (CI_TX_DESC_DTYPE_DATA |
 			((uint64_t)flags  << CI_TXD_QW1_CMD_S) |
 			((uint64_t)pkt->data_len << CI_TXD_QW1_TX_BUF_SZ_S));
@@ -266,7 +272,7 @@ static __rte_always_inline void
 ci_vtx_ctx_avx2(volatile struct ci_tx_desc *txdp,
 		struct rte_mbuf **pkt, uint16_t nb_pkts, uint64_t flags,
 		bool offload, enum ci_l2tag_pos single_vlan_pos, enum ci_l2tag_pos qinq_outer_pos,
-		bool ptype_lldp_enabled)
+		ci_tx_ctx_lldp_fn lldp_check)
 {
 	uint64_t hi_data_qw_tmpl = (CI_TX_DESC_DTYPE_DATA | (flags  << CI_TXD_QW1_CMD_S));
 
@@ -300,8 +306,8 @@ ci_vtx_ctx_avx2(volatile struct ci_tx_desc *txdp,
 				low_ctx_qw1 |= (uint64_t)pkt[1]->vlan_tci << CI_TXD_CTX_QW0_L2TAG2_S;
 			}
 		}
-		if (IAVF_CHECK_TX_LLDP(pkt[1], ptype_lldp_enabled))
-			hi_ctx_qw1 |= IAVF_TX_CTX_DESC_SWTCH_UPLINK << CI_TXD_QW1_CMD_S;
+		if (lldp_check != NULL)
+			hi_ctx_qw1 = lldp_check(pkt[1], hi_ctx_qw1);
 
 		if (offload) {
 			/* tunnel fill assigns low_ctx_qw0; must run before QinQ/VLAN OR below */
@@ -318,8 +324,8 @@ ci_vtx_ctx_avx2(volatile struct ci_tx_desc *txdp,
 				low_ctx_qw0 |= (uint64_t)pkt[0]->vlan_tci << CI_TXD_CTX_QW0_L2TAG2_S;
 			}
 		}
-		if (IAVF_CHECK_TX_LLDP(pkt[0], ptype_lldp_enabled))
-			hi_ctx_qw0 |= IAVF_TX_CTX_DESC_SWTCH_UPLINK << CI_TXD_QW1_CMD_S;
+		if (lldp_check != NULL)
+			hi_ctx_qw0 = lldp_check(pkt[0], hi_ctx_qw0);
 
 		if (offload) {
 			ci_tx_vec_offload(pkt[1], &hi_data_qw1, single_vlan_pos, qinq_outer_pos);
@@ -338,7 +344,7 @@ ci_vtx_ctx_avx2(volatile struct ci_tx_desc *txdp,
 
 	if (nb_pkts)
 		ci_vtx1_ctx_avx2(txdp, *pkt, flags, offload,
-				single_vlan_pos, qinq_outer_pos, ptype_lldp_enabled);
+				single_vlan_pos, qinq_outer_pos, lldp_check);
 }
 
 #endif /* __AVX2__ */
@@ -398,7 +404,7 @@ ci_vtx_avx512(volatile struct ci_tx_desc *txdp,
 static __rte_always_inline void
 ci_vtx1_ctx_avx512(volatile struct ci_tx_desc *txdp, struct rte_mbuf *pkt,
 		uint64_t flags, bool offload, enum ci_l2tag_pos single_vlan_pos,
-		enum ci_l2tag_pos qinq_outer_pos, bool lldp_enabled)
+		enum ci_l2tag_pos qinq_outer_pos, ci_tx_ctx_lldp_fn lldp_check)
 {
 	uint64_t high_ctx_qw = CI_TX_DESC_DTYPE_CTX;
 	uint64_t low_ctx_qw = 0;
@@ -417,8 +423,8 @@ ci_vtx1_ctx_avx512(volatile struct ci_tx_desc *txdp, struct rte_mbuf *pkt,
 			low_ctx_qw |= (uint64_t)pkt->vlan_tci << CI_TXD_CTX_QW0_L2TAG2_S;
 		}
 	}
-	if (IAVF_CHECK_TX_LLDP(pkt, lldp_enabled))
-		high_ctx_qw |= IAVF_TX_CTX_DESC_SWTCH_UPLINK << CI_TXD_QW1_CMD_S;
+	if (lldp_check != NULL)
+		high_ctx_qw = lldp_check(pkt, high_ctx_qw);
 	uint64_t high_data_qw = (CI_TX_DESC_DTYPE_DATA |
 			((uint64_t)flags << CI_TXD_QW1_CMD_S) |
 			((uint64_t)pkt->data_len << CI_TXD_QW1_TX_BUF_SZ_S));
@@ -437,7 +443,7 @@ static __rte_always_inline void
 ci_vtx_ctx_avx512(volatile struct ci_tx_desc *txdp,
 		struct rte_mbuf **pkt, uint16_t nb_pkts,  uint64_t flags,
 		bool offload, enum ci_l2tag_pos single_vlan_pos, enum ci_l2tag_pos qinq_outer_pos,
-		bool lldp_enabled)
+		ci_tx_ctx_lldp_fn lldp_check)
 {
 	uint64_t hi_data_qw_tmpl = (CI_TX_DESC_DTYPE_DATA | (flags << CI_TXD_QW1_CMD_S));
 
@@ -469,8 +475,8 @@ ci_vtx_ctx_avx512(volatile struct ci_tx_desc *txdp,
 				low_ctx_qw1 |= (uint64_t)pkt[1]->vlan_tci << CI_TXD_CTX_QW0_L2TAG2_S;
 			}
 		}
-		if (IAVF_CHECK_TX_LLDP(pkt[1], lldp_enabled))
-			hi_ctx_qw1 |= IAVF_TX_CTX_DESC_SWTCH_UPLINK << CI_TXD_QW1_CMD_S;
+		if (lldp_check != NULL)
+			hi_ctx_qw1 = lldp_check(pkt[1], hi_ctx_qw1);
 
 		if (offload) {
 			/* tunnel fill assigns low_ctx_qw0; must run before QinQ/VLAN OR below */
@@ -487,8 +493,8 @@ ci_vtx_ctx_avx512(volatile struct ci_tx_desc *txdp,
 				low_ctx_qw0 |= (uint64_t)pkt[0]->vlan_tci << CI_TXD_CTX_QW0_L2TAG2_S;
 			}
 		}
-		if (IAVF_CHECK_TX_LLDP(pkt[0], lldp_enabled))
-			hi_ctx_qw0 |= IAVF_TX_CTX_DESC_SWTCH_UPLINK << CI_TXD_QW1_CMD_S;
+		if (lldp_check != NULL)
+			hi_ctx_qw0 = lldp_check(pkt[0], hi_ctx_qw0);
 
 		if (offload) {
 			ci_tx_vec_offload(pkt[1], &hi_data_qw1, single_vlan_pos, qinq_outer_pos);
@@ -505,7 +511,7 @@ ci_vtx_ctx_avx512(volatile struct ci_tx_desc *txdp,
 
 	if (nb_pkts)
 		ci_vtx1_ctx_avx512(txdp, *pkt, flags, offload,
-				single_vlan_pos, qinq_outer_pos, lldp_enabled);
+					single_vlan_pos, qinq_outer_pos, lldp_check);
 }
 
 #endif /* __AVX512VL__ */
diff --git a/drivers/net/intel/iavf/iavf_rxtx_vec_avx2.c b/drivers/net/intel/iavf/iavf_rxtx_vec_avx2.c
index 1d0492edd9..813611015d 100644
--- a/drivers/net/intel/iavf/iavf_rxtx_vec_avx2.c
+++ b/drivers/net/intel/iavf/iavf_rxtx_vec_avx2.c
@@ -1685,6 +1685,14 @@ iavf_xmit_fixed_burst_vec_avx2(void *tx_queue, struct rte_mbuf **tx_pkts,
 	return nb_pkts;
 }
 
+static __rte_always_inline uint64_t
+iavf_tx_ctx_lldp_check(struct rte_mbuf *pkt, uint64_t high_ctx_qw)
+{
+	if (IAVF_CHECK_TX_LLDP(pkt, true))
+		high_ctx_qw |= IAVF_TX_CTX_DESC_SWTCH_UPLINK << CI_TXD_QW1_CMD_S;
+	return high_ctx_qw;
+}
+
 static __rte_always_inline uint16_t
 iavf_xmit_fixed_burst_vec_avx2_ctx(void *tx_queue, struct rte_mbuf **tx_pkts,
 				 uint16_t nb_pkts, bool offload)
@@ -1696,7 +1704,7 @@ iavf_xmit_fixed_burst_vec_avx2_ctx(void *tx_queue, struct rte_mbuf **tx_pkts,
 	/* bit2 is reserved and must be set to 1 according to Spec */
 	uint64_t flags = IAVF_TX_DESC_CMD_EOP | IAVF_TX_DESC_CMD_ICRC;
 	uint64_t rs = IAVF_TX_DESC_CMD_RS | flags;
-	bool lldp_enabled = txq->lldp_enabled;
+	ci_tx_ctx_lldp_fn lldp_check = txq->lldp_enabled ? iavf_tx_ctx_lldp_check : NULL;
 	/* vlan_flag gives both the single-VLAN and the QinQ outer tag position */
 	enum ci_l2tag_pos vlan_pos = (txq->vlan_flag & IAVF_TX_FLAGS_VLAN_TAG_LOC_L2TAG1) ?
 			CI_TAG_IN_DATA_DESC : CI_TAG_IN_CTX_DESC;
@@ -1723,10 +1731,10 @@ iavf_xmit_fixed_burst_vec_avx2_ctx(void *tx_queue, struct rte_mbuf **tx_pkts,
 		ci_tx_backlog_entry_vec(txep, tx_pkts, nb_mbuf);
 
 		ci_vtx_ctx_avx2(txdp, tx_pkts, nb_mbuf - 1, flags, offload,
-				vlan_pos, vlan_pos, lldp_enabled);
+				vlan_pos, vlan_pos, lldp_check);
 		tx_pkts += (nb_mbuf - 1);
 		txdp += (n - 2);
-		ci_vtx1_ctx_avx2(txdp, *tx_pkts++, rs, offload, vlan_pos, vlan_pos, lldp_enabled);
+		ci_vtx1_ctx_avx2(txdp, *tx_pkts++, rs, offload, vlan_pos, vlan_pos, lldp_check);
 
 		nb_commit = (uint16_t)(nb_commit - n);
 
@@ -1740,7 +1748,7 @@ iavf_xmit_fixed_burst_vec_avx2_ctx(void *tx_queue, struct rte_mbuf **tx_pkts,
 	nb_mbuf = nb_commit >> 1;
 	ci_tx_backlog_entry_vec(txep, tx_pkts, nb_mbuf);
 
-	ci_vtx_ctx_avx2(txdp, tx_pkts, nb_mbuf, flags, offload, vlan_pos, vlan_pos, lldp_enabled);
+	ci_vtx_ctx_avx2(txdp, tx_pkts, nb_mbuf, flags, offload, vlan_pos, vlan_pos, lldp_check);
 	tx_id = (uint16_t)(tx_id + nb_commit);
 
 	if (tx_id > txq->tx_next_rs) {
diff --git a/drivers/net/intel/iavf/iavf_rxtx_vec_avx512.c b/drivers/net/intel/iavf/iavf_rxtx_vec_avx512.c
index 0c738e4882..fe00416660 100644
--- a/drivers/net/intel/iavf/iavf_rxtx_vec_avx512.c
+++ b/drivers/net/intel/iavf/iavf_rxtx_vec_avx512.c
@@ -1900,6 +1900,14 @@ iavf_xmit_fixed_burst_vec_avx512(void *tx_queue, struct rte_mbuf **tx_pkts,
 	return nb_pkts;
 }
 
+static __rte_always_inline uint64_t
+iavf_tx_ctx_lldp_check(struct rte_mbuf *pkt, uint64_t high_ctx_qw)
+{
+	if (IAVF_CHECK_TX_LLDP(pkt, true))
+		high_ctx_qw |= IAVF_TX_CTX_DESC_SWTCH_UPLINK << CI_TXD_QW1_CMD_S;
+	return high_ctx_qw;
+}
+
 static __rte_always_inline uint16_t
 iavf_xmit_fixed_burst_vec_avx512_ctx(void *tx_queue, struct rte_mbuf **tx_pkts,
 				 uint16_t nb_pkts, bool offload)
@@ -1911,7 +1919,7 @@ iavf_xmit_fixed_burst_vec_avx512_ctx(void *tx_queue, struct rte_mbuf **tx_pkts,
 	/* bit2 is reserved and must be set to 1 according to Spec */
 	uint64_t flags = CI_TX_DESC_CMD_EOP | CI_TX_DESC_CMD_ICRC;
 	uint64_t rs = CI_TX_DESC_CMD_RS | flags;
-	bool lldp_enabled = txq->lldp_enabled;
+	ci_tx_ctx_lldp_fn lldp_check = txq->lldp_enabled ? iavf_tx_ctx_lldp_check : NULL;
 	/* vlan_flag gives both the single-VLAN and the QinQ outer tag position */
 	enum ci_l2tag_pos vlan_pos = (txq->vlan_flag & IAVF_TX_FLAGS_VLAN_TAG_LOC_L2TAG1) ?
 			CI_TAG_IN_DATA_DESC : CI_TAG_IN_CTX_DESC;
@@ -1938,11 +1946,10 @@ iavf_xmit_fixed_burst_vec_avx512_ctx(void *tx_queue, struct rte_mbuf **tx_pkts,
 		tx_backlog_entry_avx512(txep, tx_pkts, nb_mbuf);
 
 		ci_vtx_ctx_avx512(txdp, tx_pkts, nb_mbuf - 1, flags, offload,
-				vlan_pos, vlan_pos, lldp_enabled);
+				vlan_pos, vlan_pos, lldp_check);
 		tx_pkts += (nb_mbuf - 1);
 		txdp += (n - 2);
-		ci_vtx1_ctx_avx512(txdp, *tx_pkts++, rs, offload,
-				vlan_pos, vlan_pos, lldp_enabled);
+		ci_vtx1_ctx_avx512(txdp, *tx_pkts++, rs, offload, vlan_pos, vlan_pos, lldp_check);
 
 		nb_commit = (uint16_t)(nb_commit - n);
 
@@ -1956,7 +1963,7 @@ iavf_xmit_fixed_burst_vec_avx512_ctx(void *tx_queue, struct rte_mbuf **tx_pkts,
 	nb_mbuf = nb_commit >> 1;
 	tx_backlog_entry_avx512(txep, tx_pkts, nb_mbuf);
 
-	ci_vtx_ctx_avx512(txdp, tx_pkts, nb_mbuf, flags, offload, vlan_pos, vlan_pos, lldp_enabled);
+	ci_vtx_ctx_avx512(txdp, tx_pkts, nb_mbuf, flags, offload, vlan_pos, vlan_pos, lldp_check);
 	tx_id = (uint16_t)(tx_id + nb_commit);
 
 	if (tx_id > txq->tx_next_rs) {
-- 
2.53.0



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