net/sfc: support EF100 Tx override prefix

Add internal mbuf dynamic flag and field to request EF100 native
Tx datapath to use Tx prefix descriptor to override egress m-port.
Overriding egress m-port is necessary on representor Tx burst
so that the packet will reach corresponding VF.

Signed-off-by: Igor Romanov <igor.romanov@oktetlabs.ru>
Signed-off-by: Andrew Rybchenko <andrew.rybchenko@oktetlabs.ru>
Reviewed-by: Andy Moreton <amoreton@xilinx.com>
Reviewed-by: Ivan Malov <ivan.malov@oktetlabs.ru>

drivers/net/sfc/sfc_dp.c

@@ -12,6 +12,9 @@
 #include <errno.h>
 
 #include <rte_log.h>
+#include <rte_mbuf_dyn.h>
+
+#include "efx.h"
 
 #include "sfc_dp.h"
 #include "sfc_log.h"
@@ -77,3 +80,46 @@ sfc_dp_register(struct sfc_dp_list *head, struct sfc_dp *entry)
 
 	return 0;
 }
+
+uint64_t sfc_dp_mport_override;
+int sfc_dp_mport_offset = -1;
+
+int
+sfc_dp_mport_register(void)
+{
+	static const struct rte_mbuf_dynfield mport = {
+		.name = "rte_net_sfc_dynfield_mport",
+		.size = sizeof(efx_mport_id_t),
+		.align = __alignof__(efx_mport_id_t),
+	};
+	static const struct rte_mbuf_dynflag mport_override = {
+		.name = "rte_net_sfc_dynflag_mport_override",
+	};
+
+	int field_offset;
+	int flag;
+
+	if (sfc_dp_mport_override != 0) {
+		SFC_GENERIC_LOG(INFO, "%s() already registered", __func__);
+		return 0;
+	}
+
+	field_offset = rte_mbuf_dynfield_register(&mport);
+	if (field_offset < 0) {
+		SFC_GENERIC_LOG(ERR, "%s() failed to register mport dynfield",
+				__func__);
+		return -1;
+	}
+
+	flag = rte_mbuf_dynflag_register(&mport_override);
+	if (flag < 0) {
+		SFC_GENERIC_LOG(ERR, "%s() failed to register mport dynflag",
+				__func__);
+		return -1;
+	}
+
+	sfc_dp_mport_offset = field_offset;
+	sfc_dp_mport_override = UINT64_C(1) << flag;
+
+	return 0;
+}

drivers/net/sfc/sfc_dp.h

@@ -128,6 +128,31 @@ struct sfc_dp *sfc_dp_find_by_caps(struct sfc_dp_list *head,
 				   unsigned int avail_caps);
 int sfc_dp_register(struct sfc_dp_list *head, struct sfc_dp *entry);
 
+/**
+ * Dynamically registered mbuf flag "mport_override" (as a bitmask).
+ *
+ * If this flag is set in an mbuf then the dynamically registered
+ * mbuf field "mport" holds a valid value. This is used to direct
+ * port representor transmit traffic to the correct target port.
+ */
+extern uint64_t sfc_dp_mport_override;
+
+/**
+ * Dynamically registered mbuf field "mport" (mbuf byte offset).
+ *
+ * If the dynamically registered "mport_override" flag is set in
+ * an mbuf then the mbuf "mport" field holds a valid value. This
+ * is used to direct port representor transmit traffic to the
+ * correct target port.
+ */
+extern int sfc_dp_mport_offset;
+
+/**
+ * Register dynamic mbuf flag and field which can be used to require Tx override
+ * prefix descriptor with egress mport set.
+ */
+int sfc_dp_mport_register(void);
+
 #ifdef __cplusplus
 }
 #endif

drivers/net/sfc/sfc_ef100_tx.c

@@ -10,6 +10,7 @@
 #include <stdbool.h>
 
 #include <rte_mbuf.h>
+#include <rte_mbuf_dyn.h>
 #include <rte_io.h>
 #include <rte_net.h>
 
@@ -309,6 +310,19 @@ sfc_ef100_tx_reap(struct sfc_ef100_txq *txq)
 	sfc_ef100_tx_reap_num_descs(txq, sfc_ef100_tx_process_events(txq));
 }
 
+static void
+sfc_ef100_tx_qdesc_prefix_create(const struct rte_mbuf *m, efx_oword_t *tx_desc)
+{
+	efx_mport_id_t *mport_id =
+		RTE_MBUF_DYNFIELD(m, sfc_dp_mport_offset, efx_mport_id_t *);
+
+	EFX_POPULATE_OWORD_3(*tx_desc,
+			ESF_GZ_TX_PREFIX_EGRESS_MPORT,
+			mport_id->id,
+			ESF_GZ_TX_PREFIX_EGRESS_MPORT_EN, 1,
+			ESF_GZ_TX_DESC_TYPE, ESE_GZ_TX_DESC_TYPE_PREFIX);
+}
+
 static uint8_t
 sfc_ef100_tx_qdesc_cso_inner_l3(uint64_t tx_tunnel)
 {
@@ -525,6 +539,11 @@ sfc_ef100_tx_pkt_descs_max(const struct rte_mbuf *m)
 				 SFC_MBUF_SEG_LEN_MAX));
 	}
 
+	if (m->ol_flags & sfc_dp_mport_override) {
+		/* Tx override prefix descriptor will be used */
+		extra_descs++;
+	}
+
 	/*
 	 * Any segment of scattered packet cannot be bigger than maximum
 	 * segment length. Make sure that subsequent segments do not need
@@ -671,6 +690,12 @@ sfc_ef100_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts, uint16_t nb_pkts)
 				break;
 		}
 
+		if (m_seg->ol_flags & sfc_dp_mport_override) {
+			id = added++ & txq->ptr_mask;
+			sfc_ef100_tx_qdesc_prefix_create(m_seg,
+							 &txq->txq_hw_ring[id]);
+		}
+
 		if (m_seg->ol_flags & PKT_TX_TCP_SEG) {
 			m_seg = sfc_ef100_xmit_tso_pkt(txq, m_seg, &added);
 		} else {

drivers/net/sfc/sfc_ethdev.c

@@ -2301,6 +2301,10 @@ sfc_eth_dev_init(struct rte_eth_dev *dev)
 		return 1;
 	}
 
+	rc = sfc_dp_mport_register();
+	if (rc != 0)
+		return rc;
+
 	sfc_register_dp();
 
 	logtype_main = sfc_register_logtype(&pci_dev->addr,