X-Git-Url: http://git.droids-corp.org/?a=blobdiff_plain;f=drivers%2Fnet%2Fsfc%2Fsfc_tx.c;h=d1320f462dda918cdb2b18580c117083c4f57c13;hb=37f8a41ad07340c3db8a6bff2905ce5c954429ea;hp=3f38066536e1e4a6b95206619853723463ec8b1b;hpb=fed9aeb46c19974a3fda2536840598196f002f8d;p=dpdk.git

diff --git a/drivers/net/sfc/sfc_tx.c b/drivers/net/sfc/sfc_tx.c
index 3f38066536..d1320f462d 100644
--- a/drivers/net/sfc/sfc_tx.c
+++ b/drivers/net/sfc/sfc_tx.c
@@ -1,5 +1,7 @@
 /*-
- * Copyright (c) 2016 Solarflare Communications Inc.
+ *   BSD LICENSE
+ *
+ * Copyright (c) 2016-2017 Solarflare Communications Inc.
  * All rights reserved.
  *
  * This software was jointly developed between OKTET Labs (under contract
@@ -32,6 +34,8 @@
 #include "sfc_log.h"
 #include "sfc_ev.h"
 #include "sfc_tx.h"
+#include "sfc_tweak.h"
+#include "sfc_kvargs.h"
 
 /*
  * Maximum number of TX queue flush attempts in case of
@@ -53,10 +57,11 @@
 #define SFC_TX_QFLUSH_POLL_ATTEMPTS	(2000)
 
 static int
-sfc_tx_qcheck_conf(struct sfc_adapter *sa,
+sfc_tx_qcheck_conf(struct sfc_adapter *sa, uint16_t nb_tx_desc,
 		   const struct rte_eth_txconf *tx_conf)
 {
 	unsigned int flags = tx_conf->txq_flags;
+	const efx_nic_cfg_t *encp = efx_nic_cfg_get(sa->nic);
 	int rc = 0;
 
 	if (tx_conf->tx_rs_thresh != 0) {
@@ -64,30 +69,54 @@ sfc_tx_qcheck_conf(struct sfc_adapter *sa,
 		rc = EINVAL;
 	}
 
-	if (tx_conf->tx_free_thresh != 0) {
+	if (tx_conf->tx_free_thresh > EFX_TXQ_LIMIT(nb_tx_desc)) {
 		sfc_err(sa,
-			"setting explicit TX free threshold is not supported");
-		rc = EINVAL;
-	}
-
-	if (tx_conf->tx_deferred_start != 0) {
-		sfc_err(sa, "TX queue deferred start is not supported (yet)");
+			"TxQ free threshold too large: %u vs maximum %u",
+			tx_conf->tx_free_thresh, EFX_TXQ_LIMIT(nb_tx_desc));
 		rc = EINVAL;
 	}
 
 	if (tx_conf->tx_thresh.pthresh != 0 ||
 	    tx_conf->tx_thresh.hthresh != 0 ||
 	    tx_conf->tx_thresh.wthresh != 0) {
-		sfc_err(sa,
+		sfc_warn(sa,
 			"prefetch/host/writeback thresholds are not supported");
+	}
+
+	if (((flags & ETH_TXQ_FLAGS_NOMULTSEGS) == 0) &&
+	    (~sa->dp_tx->features & SFC_DP_TX_FEAT_MULTI_SEG)) {
+		sfc_err(sa, "Multi-segment is not supported by %s datapath",
+			sa->dp_tx->dp.name);
 		rc = EINVAL;
 	}
 
-	if ((flags & ETH_TXQ_FLAGS_NOVLANOFFL) == 0) {
-		sfc_err(sa, "VLAN offload is not supported");
+	if (((flags & ETH_TXQ_FLAGS_NOMULTMEMP) == 0) &&
+	    (~sa->dp_tx->features & SFC_DP_TX_FEAT_MULTI_POOL)) {
+		sfc_err(sa, "multi-mempool is not supported by %s datapath",
+			sa->dp_tx->dp.name);
 		rc = EINVAL;
 	}
 
+	if (((flags & ETH_TXQ_FLAGS_NOREFCOUNT) == 0) &&
+	    (~sa->dp_tx->features & SFC_DP_TX_FEAT_REFCNT)) {
+		sfc_err(sa,
+			"mbuf reference counters are neglected by %s datapath",
+			sa->dp_tx->dp.name);
+		rc = EINVAL;
+	}
+
+	if ((flags & ETH_TXQ_FLAGS_NOVLANOFFL) == 0) {
+		if (!encp->enc_hw_tx_insert_vlan_enabled) {
+			sfc_err(sa, "VLAN offload is not supported");
+			rc = EINVAL;
+		} else if (~sa->dp_tx->features & SFC_DP_TX_FEAT_VLAN_INSERT) {
+			sfc_err(sa,
+				"VLAN offload is not supported by %s datapath",
+				sa->dp_tx->dp.name);
+			rc = EINVAL;
+		}
+	}
+
 	if ((flags & ETH_TXQ_FLAGS_NOXSUMSCTP) == 0) {
 		sfc_err(sa, "SCTP offload is not supported");
 		rc = EINVAL;
@@ -110,43 +139,21 @@ sfc_tx_qflush_done(struct sfc_txq *txq)
 	txq->state &= ~SFC_TXQ_FLUSHING;
 }
 
-static void
-sfc_tx_reap(struct sfc_txq *txq)
-{
-	unsigned int    completed;
-
-
-	sfc_ev_qpoll(txq->evq);
-
-	for (completed = txq->completed;
-	     completed != txq->pending; completed++) {
-		struct sfc_tx_sw_desc *txd;
-
-		txd = &txq->sw_ring[completed & txq->ptr_mask];
-
-		if (txd->mbuf != NULL) {
-			rte_pktmbuf_free(txd->mbuf);
-			txd->mbuf = NULL;
-		}
-	}
-
-	txq->completed = completed;
-}
-
 int
 sfc_tx_qinit(struct sfc_adapter *sa, unsigned int sw_index,
 	     uint16_t nb_tx_desc, unsigned int socket_id,
 	     const struct rte_eth_txconf *tx_conf)
 {
+	const efx_nic_cfg_t *encp = efx_nic_cfg_get(sa->nic);
 	struct sfc_txq_info *txq_info;
 	struct sfc_evq *evq;
 	struct sfc_txq *txq;
-	unsigned int evq_index = sfc_evq_index_by_txq_sw_index(sa, sw_index);
 	int rc = 0;
+	struct sfc_dp_tx_qcreate_info info;
 
 	sfc_log_init(sa, "TxQ = %u", sw_index);
 
-	rc = sfc_tx_qcheck_conf(sa, tx_conf);
+	rc = sfc_tx_qcheck_conf(sa, nb_tx_desc, tx_conf);
 	if (rc != 0)
 		goto fail_bad_conf;
 
@@ -156,58 +163,64 @@ sfc_tx_qinit(struct sfc_adapter *sa, unsigned int sw_index,
 	SFC_ASSERT(nb_tx_desc <= sa->txq_max_entries);
 	txq_info->entries = nb_tx_desc;
 
-	rc = sfc_ev_qinit(sa, evq_index, txq_info->entries, socket_id);
+	rc = sfc_ev_qinit(sa, SFC_EVQ_TYPE_TX, sw_index,
+			  txq_info->entries, socket_id, &evq);
 	if (rc != 0)
 		goto fail_ev_qinit;
 
-	evq = sa->evq_info[evq_index].evq;
-
 	rc = ENOMEM;
 	txq = rte_zmalloc_socket("sfc-txq", sizeof(*txq), 0, socket_id);
 	if (txq == NULL)
 		goto fail_txq_alloc;
 
+	txq_info->txq = txq;
+
+	txq->hw_index = sw_index;
+	txq->evq = evq;
+	txq->free_thresh =
+		(tx_conf->tx_free_thresh) ? tx_conf->tx_free_thresh :
+		SFC_TX_DEFAULT_FREE_THRESH;
+	txq->flags = tx_conf->txq_flags;
+
 	rc = sfc_dma_alloc(sa, "txq", sw_index, EFX_TXQ_SIZE(txq_info->entries),
 			   socket_id, &txq->mem);
 	if (rc != 0)
 		goto fail_dma_alloc;
 
-	rc = ENOMEM;
-	txq->pend_desc = rte_calloc_socket("sfc-txq-pend-desc",
-					   EFX_TXQ_LIMIT(txq_info->entries),
-					   sizeof(efx_desc_t), 0, socket_id);
-	if (txq->pend_desc == NULL)
-		goto fail_pend_desc_alloc;
+	memset(&info, 0, sizeof(info));
+	info.free_thresh = txq->free_thresh;
+	info.flags = tx_conf->txq_flags;
+	info.txq_entries = txq_info->entries;
+	info.dma_desc_size_max = encp->enc_tx_dma_desc_size_max;
+	info.txq_hw_ring = txq->mem.esm_base;
+	info.evq_entries = txq_info->entries;
+	info.evq_hw_ring = evq->mem.esm_base;
+	info.hw_index = txq->hw_index;
+	info.mem_bar = sa->mem_bar.esb_base;
+
+	rc = sa->dp_tx->qcreate(sa->eth_dev->data->port_id, sw_index,
+				&RTE_ETH_DEV_TO_PCI(sa->eth_dev)->addr,
+				socket_id, &info, &txq->dp);
+	if (rc != 0)
+		goto fail_dp_tx_qinit;
 
-	rc = ENOMEM;
-	txq->sw_ring = rte_calloc_socket("sfc-txq-desc", txq_info->entries,
-					 sizeof(*txq->sw_ring), 0, socket_id);
-	if (txq->sw_ring == NULL)
-		goto fail_desc_alloc;
+	evq->dp_txq = txq->dp;
 
 	txq->state = SFC_TXQ_INITIALIZED;
-	txq->ptr_mask = txq_info->entries - 1;
-	txq->hw_index = sw_index;
-	txq->flags = tx_conf->txq_flags;
-	txq->evq = evq;
-
-	evq->txq = txq;
 
-	txq_info->txq = txq;
+	txq_info->deferred_start = (tx_conf->tx_deferred_start != 0);
 
 	return 0;
 
-fail_desc_alloc:
-	rte_free(txq->pend_desc);
-
-fail_pend_desc_alloc:
+fail_dp_tx_qinit:
 	sfc_dma_free(sa, &txq->mem);
 
 fail_dma_alloc:
+	txq_info->txq = NULL;
 	rte_free(txq);
 
 fail_txq_alloc:
-	sfc_ev_qfini(sa, evq_index);
+	sfc_ev_qfini(evq);
 
 fail_ev_qinit:
 	txq_info->entries = 0;
@@ -232,12 +245,17 @@ sfc_tx_qfini(struct sfc_adapter *sa, unsigned int sw_index)
 	SFC_ASSERT(txq != NULL);
 	SFC_ASSERT(txq->state == SFC_TXQ_INITIALIZED);
 
+	sa->dp_tx->qdestroy(txq->dp);
+	txq->dp = NULL;
+
 	txq_info->txq = NULL;
 	txq_info->entries = 0;
 
-	rte_free(txq->sw_ring);
-	rte_free(txq->pend_desc);
 	sfc_dma_free(sa, &txq->mem);
+
+	sfc_ev_qfini(txq->evq);
+	txq->evq = NULL;
+
 	rte_free(txq);
 }
 
@@ -285,59 +303,108 @@ sfc_tx_check_mode(struct sfc_adapter *sa, const struct rte_eth_txmode *txmode)
 	return rc;
 }
 
+/**
+ * Destroy excess queues that are no longer needed after reconfiguration
+ * or complete close.
+ */
+static void
+sfc_tx_fini_queues(struct sfc_adapter *sa, unsigned int nb_tx_queues)
+{
+	int sw_index;
+
+	SFC_ASSERT(nb_tx_queues <= sa->txq_count);
+
+	sw_index = sa->txq_count;
+	while (--sw_index >= (int)nb_tx_queues) {
+		if (sa->txq_info[sw_index].txq != NULL)
+			sfc_tx_qfini(sa, sw_index);
+	}
+
+	sa->txq_count = nb_tx_queues;
+}
+
 int
-sfc_tx_init(struct sfc_adapter *sa)
+sfc_tx_configure(struct sfc_adapter *sa)
 {
+	const efx_nic_cfg_t *encp = efx_nic_cfg_get(sa->nic);
 	const struct rte_eth_conf *dev_conf = &sa->eth_dev->data->dev_conf;
-	unsigned int sw_index;
+	const unsigned int nb_tx_queues = sa->eth_dev->data->nb_tx_queues;
 	int rc = 0;
 
+	sfc_log_init(sa, "nb_tx_queues=%u (old %u)",
+		     nb_tx_queues, sa->txq_count);
+
+	/*
+	 * The datapath implementation assumes absence of boundary
+	 * limits on Tx DMA descriptors. Addition of these checks on
+	 * datapath would simply make the datapath slower.
+	 */
+	if (encp->enc_tx_dma_desc_boundary != 0) {
+		rc = ENOTSUP;
+		goto fail_tx_dma_desc_boundary;
+	}
+
 	rc = sfc_tx_check_mode(sa, &dev_conf->txmode);
 	if (rc != 0)
 		goto fail_check_mode;
 
-	sa->txq_count = sa->eth_dev->data->nb_tx_queues;
-
-	sa->txq_info = rte_calloc_socket("sfc-txqs", sa->txq_count,
-					 sizeof(sa->txq_info[0]), 0,
-					 sa->socket_id);
-	if (sa->txq_info == NULL)
-		goto fail_txqs_alloc;
+	if (nb_tx_queues == sa->txq_count)
+		goto done;
+
+	if (sa->txq_info == NULL) {
+		sa->txq_info = rte_calloc_socket("sfc-txqs", nb_tx_queues,
+						 sizeof(sa->txq_info[0]), 0,
+						 sa->socket_id);
+		if (sa->txq_info == NULL)
+			goto fail_txqs_alloc;
+	} else {
+		struct sfc_txq_info *new_txq_info;
+
+		if (nb_tx_queues < sa->txq_count)
+			sfc_tx_fini_queues(sa, nb_tx_queues);
+
+		new_txq_info =
+			rte_realloc(sa->txq_info,
+				    nb_tx_queues * sizeof(sa->txq_info[0]), 0);
+		if (new_txq_info == NULL && nb_tx_queues > 0)
+			goto fail_txqs_realloc;
+
+		sa->txq_info = new_txq_info;
+		if (nb_tx_queues > sa->txq_count)
+			memset(&sa->txq_info[sa->txq_count], 0,
+			       (nb_tx_queues - sa->txq_count) *
+			       sizeof(sa->txq_info[0]));
+	}
 
-	for (sw_index = 0; sw_index < sa->txq_count; ++sw_index) {
-		rc = sfc_tx_qinit_info(sa, sw_index);
+	while (sa->txq_count < nb_tx_queues) {
+		rc = sfc_tx_qinit_info(sa, sa->txq_count);
 		if (rc != 0)
 			goto fail_tx_qinit_info;
+
+		sa->txq_count++;
 	}
 
+done:
 	return 0;
 
 fail_tx_qinit_info:
-	rte_free(sa->txq_info);
-	sa->txq_info = NULL;
-
+fail_txqs_realloc:
 fail_txqs_alloc:
-	sa->txq_count = 0;
+	sfc_tx_close(sa);
 
 fail_check_mode:
+fail_tx_dma_desc_boundary:
 	sfc_log_init(sa, "failed (rc = %d)", rc);
 	return rc;
 }
 
 void
-sfc_tx_fini(struct sfc_adapter *sa)
+sfc_tx_close(struct sfc_adapter *sa)
 {
-	int sw_index;
-
-	sw_index = sa->txq_count;
-	while (--sw_index >= 0) {
-		if (sa->txq_info[sw_index].txq != NULL)
-			sfc_tx_qfini(sa, sw_index);
-	}
+	sfc_tx_fini_queues(sa, 0);
 
 	rte_free(sa->txq_info);
 	sa->txq_info = NULL;
-	sa->txq_count = 0;
 }
 
 int
@@ -362,7 +429,7 @@ sfc_tx_qstart(struct sfc_adapter *sa, unsigned int sw_index)
 
 	evq = txq->evq;
 
-	rc = sfc_ev_qstart(sa, evq->evq_index);
+	rc = sfc_ev_qstart(evq, sfc_evq_index_by_txq_sw_index(sa, sw_index));
 	if (rc != 0)
 		goto fail_ev_qstart;
 
@@ -371,23 +438,33 @@ sfc_tx_qstart(struct sfc_adapter *sa, unsigned int sw_index)
 	 * hence, we always enable it here
 	 */
 	if ((txq->flags & ETH_TXQ_FLAGS_NOXSUMTCP) ||
-	    (txq->flags & ETH_TXQ_FLAGS_NOXSUMUDP))
+	    (txq->flags & ETH_TXQ_FLAGS_NOXSUMUDP)) {
 		flags = EFX_TXQ_CKSUM_IPV4;
-	else
+	} else {
 		flags = EFX_TXQ_CKSUM_IPV4 | EFX_TXQ_CKSUM_TCPUDP;
 
+		if (sa->tso)
+			flags |= EFX_TXQ_FATSOV2;
+	}
+
 	rc = efx_tx_qcreate(sa->nic, sw_index, 0, &txq->mem,
 			    txq_info->entries, 0 /* not used on EF10 */,
 			    flags, evq->common,
 			    &txq->common, &desc_index);
-	if (rc != 0)
-		goto fail_tx_qcreate;
+	if (rc != 0) {
+		if (sa->tso && (rc == ENOSPC))
+			sfc_err(sa, "ran out of TSO contexts");
 
-	txq->added = txq->pending = txq->completed = desc_index;
+		goto fail_tx_qcreate;
+	}
 
 	efx_tx_qenable(txq->common);
 
-	txq->state |= (SFC_TXQ_STARTED | SFC_TXQ_RUNNING);
+	txq->state |= SFC_TXQ_STARTED;
+
+	rc = sa->dp_tx->qstart(txq->dp, evq->read_ptr, desc_index);
+	if (rc != 0)
+		goto fail_dp_qstart;
 
 	/*
 	 * It seems to be used by DPDK for debug purposes only ('rte_ether')
@@ -397,8 +474,12 @@ sfc_tx_qstart(struct sfc_adapter *sa, unsigned int sw_index)
 
 	return 0;
 
+fail_dp_qstart:
+	txq->state = SFC_TXQ_INITIALIZED;
+	efx_tx_qdestroy(txq->common);
+
 fail_tx_qcreate:
-	sfc_ev_qstop(sa, evq->evq_index);
+	sfc_ev_qstop(evq);
 
 fail_ev_qstart:
 	return rc;
@@ -412,7 +493,7 @@ sfc_tx_qstop(struct sfc_adapter *sa, unsigned int sw_index)
 	struct sfc_txq *txq;
 	unsigned int retry_count;
 	unsigned int wait_count;
-	unsigned int txds;
+	int rc;
 
 	sfc_log_init(sa, "TxQ = %u", sw_index);
 
@@ -421,9 +502,12 @@ sfc_tx_qstop(struct sfc_adapter *sa, unsigned int sw_index)
 
 	txq = txq_info->txq;
 
+	if (txq->state == SFC_TXQ_INITIALIZED)
+		return;
+
 	SFC_ASSERT(txq->state & SFC_TXQ_STARTED);
 
-	txq->state &= ~SFC_TXQ_RUNNING;
+	sa->dp_tx->qstop(txq->dp, &txq->evq->read_ptr);
 
 	/*
 	 * Retry TX queue flushing in case of flush failed or
@@ -433,8 +517,10 @@ sfc_tx_qstop(struct sfc_adapter *sa, unsigned int sw_index)
 	     ((txq->state & SFC_TXQ_FLUSHED) == 0) &&
 	     (retry_count < SFC_TX_QFLUSH_ATTEMPTS);
 	     ++retry_count) {
-		if (efx_tx_qflush(txq->common) != 0) {
-			txq->state |= SFC_TXQ_FLUSHING;
+		rc = efx_tx_qflush(txq->common);
+		if (rc != 0) {
+			txq->state |= (rc == EALREADY) ?
+				SFC_TXQ_FLUSHED : SFC_TXQ_FLUSH_FAILED;
 			break;
 		}
 
@@ -458,20 +544,13 @@ sfc_tx_qstop(struct sfc_adapter *sa, unsigned int sw_index)
 			sfc_info(sa, "TxQ %u flushed", sw_index);
 	}
 
-	sfc_tx_reap(txq);
-
-	for (txds = 0; txds < txq_info->entries; txds++) {
-		if (txq->sw_ring[txds].mbuf != NULL) {
-			rte_pktmbuf_free(txq->sw_ring[txds].mbuf);
-			txq->sw_ring[txds].mbuf = NULL;
-		}
-	}
+	sa->dp_tx->qreap(txq->dp);
 
 	txq->state = SFC_TXQ_INITIALIZED;
 
 	efx_tx_qdestroy(txq->common);
 
-	sfc_ev_qstop(sa, txq->evq->evq_index);
+	sfc_ev_qstop(txq->evq);
 
 	/*
 	 * It seems to be used by DPDK for debug purposes only ('rte_ether')
@@ -488,14 +567,24 @@ sfc_tx_start(struct sfc_adapter *sa)
 
 	sfc_log_init(sa, "txq_count = %u", sa->txq_count);
 
+	if (sa->tso) {
+		if (!efx_nic_cfg_get(sa->nic)->enc_fw_assisted_tso_v2_enabled) {
+			sfc_warn(sa, "TSO support was unable to be restored");
+			sa->tso = B_FALSE;
+		}
+	}
+
 	rc = efx_tx_init(sa->nic);
 	if (rc != 0)
 		goto fail_efx_tx_init;
 
 	for (sw_index = 0; sw_index < sa->txq_count; ++sw_index) {
-		rc = sfc_tx_qstart(sa, sw_index);
-		if (rc != 0)
-			goto fail_tx_qstart;
+		if (!(sa->txq_info[sw_index].deferred_start) ||
+		    sa->txq_info[sw_index].deferred_started) {
+			rc = sfc_tx_qstart(sa, sw_index);
+			if (rc != 0)
+				goto fail_tx_qstart;
+		}
 	}
 
 	return 0;
@@ -526,3 +615,436 @@ sfc_tx_stop(struct sfc_adapter *sa)
 
 	efx_tx_fini(sa->nic);
 }
+
+static void
+sfc_efx_tx_reap(struct sfc_efx_txq *txq)
+{
+	unsigned int completed;
+
+	sfc_ev_qpoll(txq->evq);
+
+	for (completed = txq->completed;
+	     completed != txq->pending; completed++) {
+		struct sfc_efx_tx_sw_desc *txd;
+
+		txd = &txq->sw_ring[completed & txq->ptr_mask];
+
+		if (txd->mbuf != NULL) {
+			rte_pktmbuf_free(txd->mbuf);
+			txd->mbuf = NULL;
+		}
+	}
+
+	txq->completed = completed;
+}
+
+/*
+ * The function is used to insert or update VLAN tag;
+ * the firmware has state of the firmware tag to insert per TxQ
+ * (controlled by option descriptors), hence, if the tag of the
+ * packet to be sent is different from one remembered by the firmware,
+ * the function will update it
+ */
+static unsigned int
+sfc_efx_tx_maybe_insert_tag(struct sfc_efx_txq *txq, struct rte_mbuf *m,
+			    efx_desc_t **pend)
+{
+	uint16_t this_tag = ((m->ol_flags & PKT_TX_VLAN_PKT) ?
+			     m->vlan_tci : 0);
+
+	if (this_tag == txq->hw_vlan_tci)
+		return 0;
+
+	/*
+	 * The expression inside SFC_ASSERT() is not desired to be checked in
+	 * a non-debug build because it might be too expensive on the data path
+	 */
+	SFC_ASSERT(efx_nic_cfg_get(txq->evq->sa->nic)->enc_hw_tx_insert_vlan_enabled);
+
+	efx_tx_qdesc_vlantci_create(txq->common, rte_cpu_to_be_16(this_tag),
+				    *pend);
+	(*pend)++;
+	txq->hw_vlan_tci = this_tag;
+
+	return 1;
+}
+
+static uint16_t
+sfc_efx_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts, uint16_t nb_pkts)
+{
+	struct sfc_dp_txq *dp_txq = (struct sfc_dp_txq *)tx_queue;
+	struct sfc_efx_txq *txq = sfc_efx_txq_by_dp_txq(dp_txq);
+	unsigned int added = txq->added;
+	unsigned int pushed = added;
+	unsigned int pkts_sent = 0;
+	efx_desc_t *pend = &txq->pend_desc[0];
+	const unsigned int hard_max_fill = EFX_TXQ_LIMIT(txq->ptr_mask + 1);
+	const unsigned int soft_max_fill = hard_max_fill - txq->free_thresh;
+	unsigned int fill_level = added - txq->completed;
+	boolean_t reap_done;
+	int rc __rte_unused;
+	struct rte_mbuf **pktp;
+
+	if (unlikely((txq->flags & SFC_EFX_TXQ_FLAG_RUNNING) == 0))
+		goto done;
+
+	/*
+	 * If insufficient space for a single packet is present,
+	 * we should reap; otherwise, we shouldn't do that all the time
+	 * to avoid latency increase
+	 */
+	reap_done = (fill_level > soft_max_fill);
+
+	if (reap_done) {
+		sfc_efx_tx_reap(txq);
+		/*
+		 * Recalculate fill level since 'txq->completed'
+		 * might have changed on reap
+		 */
+		fill_level = added - txq->completed;
+	}
+
+	for (pkts_sent = 0, pktp = &tx_pkts[0];
+	     (pkts_sent < nb_pkts) && (fill_level <= soft_max_fill);
+	     pkts_sent++, pktp++) {
+		struct rte_mbuf		*m_seg = *pktp;
+		size_t			pkt_len = m_seg->pkt_len;
+		unsigned int		pkt_descs = 0;
+		size_t			in_off = 0;
+
+		/*
+		 * Here VLAN TCI is expected to be zero in case if no
+		 * DEV_TX_VLAN_OFFLOAD capability is advertised;
+		 * if the calling app ignores the absence of
+		 * DEV_TX_VLAN_OFFLOAD and pushes VLAN TCI, then
+		 * TX_ERROR will occur
+		 */
+		pkt_descs += sfc_efx_tx_maybe_insert_tag(txq, m_seg, &pend);
+
+		if (m_seg->ol_flags & PKT_TX_TCP_SEG) {
+			/*
+			 * We expect correct 'pkt->l[2, 3, 4]_len' values
+			 * to be set correctly by the caller
+			 */
+			if (sfc_efx_tso_do(txq, added, &m_seg, &in_off, &pend,
+					   &pkt_descs, &pkt_len) != 0) {
+				/* We may have reached this place for
+				 * one of the following reasons:
+				 *
+				 * 1) Packet header length is greater
+				 *    than SFC_TSOH_STD_LEN
+				 * 2) TCP header starts at more then
+				 *    208 bytes into the frame
+				 *
+				 * We will deceive RTE saying that we have sent
+				 * the packet, but we will actually drop it.
+				 * Hence, we should revert 'pend' to the
+				 * previous state (in case we have added
+				 * VLAN descriptor) and start processing
+				 * another one packet. But the original
+				 * mbuf shouldn't be orphaned
+				 */
+				pend -= pkt_descs;
+
+				rte_pktmbuf_free(*pktp);
+
+				continue;
+			}
+
+			/*
+			 * We've only added 2 FATSOv2 option descriptors
+			 * and 1 descriptor for the linearized packet header.
+			 * The outstanding work will be done in the same manner
+			 * as for the usual non-TSO path
+			 */
+		}
+
+		for (; m_seg != NULL; m_seg = m_seg->next) {
+			efsys_dma_addr_t	next_frag;
+			size_t			seg_len;
+
+			seg_len = m_seg->data_len;
+			next_frag = rte_mbuf_data_iova(m_seg);
+
+			/*
+			 * If we've started TSO transaction few steps earlier,
+			 * we'll skip packet header using an offset in the
+			 * current segment (which has been set to the
+			 * first one containing payload)
+			 */
+			seg_len -= in_off;
+			next_frag += in_off;
+			in_off = 0;
+
+			do {
+				efsys_dma_addr_t	frag_addr = next_frag;
+				size_t			frag_len;
+
+				/*
+				 * It is assumed here that there is no
+				 * limitation on address boundary
+				 * crossing by DMA descriptor.
+				 */
+				frag_len = MIN(seg_len, txq->dma_desc_size_max);
+				next_frag += frag_len;
+				seg_len -= frag_len;
+				pkt_len -= frag_len;
+
+				efx_tx_qdesc_dma_create(txq->common,
+							frag_addr, frag_len,
+							(pkt_len == 0),
+							pend++);
+
+				pkt_descs++;
+			} while (seg_len != 0);
+		}
+
+		added += pkt_descs;
+
+		fill_level += pkt_descs;
+		if (unlikely(fill_level > hard_max_fill)) {
+			/*
+			 * Our estimation for maximum number of descriptors
+			 * required to send a packet seems to be wrong.
+			 * Try to reap (if we haven't yet).
+			 */
+			if (!reap_done) {
+				sfc_efx_tx_reap(txq);
+				reap_done = B_TRUE;
+				fill_level = added - txq->completed;
+				if (fill_level > hard_max_fill) {
+					pend -= pkt_descs;
+					break;
+				}
+			} else {
+				pend -= pkt_descs;
+				break;
+			}
+		}
+
+		/* Assign mbuf to the last used desc */
+		txq->sw_ring[(added - 1) & txq->ptr_mask].mbuf = *pktp;
+	}
+
+	if (likely(pkts_sent > 0)) {
+		rc = efx_tx_qdesc_post(txq->common, txq->pend_desc,
+				       pend - &txq->pend_desc[0],
+				       txq->completed, &txq->added);
+		SFC_ASSERT(rc == 0);
+
+		if (likely(pushed != txq->added))
+			efx_tx_qpush(txq->common, txq->added, pushed);
+	}
+
+#if SFC_TX_XMIT_PKTS_REAP_AT_LEAST_ONCE
+	if (!reap_done)
+		sfc_efx_tx_reap(txq);
+#endif
+
+done:
+	return pkts_sent;
+}
+
+struct sfc_txq *
+sfc_txq_by_dp_txq(const struct sfc_dp_txq *dp_txq)
+{
+	const struct sfc_dp_queue *dpq = &dp_txq->dpq;
+	struct rte_eth_dev *eth_dev;
+	struct sfc_adapter *sa;
+	struct sfc_txq *txq;
+
+	SFC_ASSERT(rte_eth_dev_is_valid_port(dpq->port_id));
+	eth_dev = &rte_eth_devices[dpq->port_id];
+
+	sa = eth_dev->data->dev_private;
+
+	SFC_ASSERT(dpq->queue_id < sa->txq_count);
+	txq = sa->txq_info[dpq->queue_id].txq;
+
+	SFC_ASSERT(txq != NULL);
+	return txq;
+}
+
+static sfc_dp_tx_qcreate_t sfc_efx_tx_qcreate;
+static int
+sfc_efx_tx_qcreate(uint16_t port_id, uint16_t queue_id,
+		   const struct rte_pci_addr *pci_addr,
+		   int socket_id,
+		   const struct sfc_dp_tx_qcreate_info *info,
+		   struct sfc_dp_txq **dp_txqp)
+{
+	struct sfc_efx_txq *txq;
+	struct sfc_txq *ctrl_txq;
+	int rc;
+
+	rc = ENOMEM;
+	txq = rte_zmalloc_socket("sfc-efx-txq", sizeof(*txq),
+				 RTE_CACHE_LINE_SIZE, socket_id);
+	if (txq == NULL)
+		goto fail_txq_alloc;
+
+	sfc_dp_queue_init(&txq->dp.dpq, port_id, queue_id, pci_addr);
+
+	rc = ENOMEM;
+	txq->pend_desc = rte_calloc_socket("sfc-efx-txq-pend-desc",
+					   EFX_TXQ_LIMIT(info->txq_entries),
+					   sizeof(*txq->pend_desc), 0,
+					   socket_id);
+	if (txq->pend_desc == NULL)
+		goto fail_pend_desc_alloc;
+
+	rc = ENOMEM;
+	txq->sw_ring = rte_calloc_socket("sfc-efx-txq-sw_ring",
+					 info->txq_entries,
+					 sizeof(*txq->sw_ring),
+					 RTE_CACHE_LINE_SIZE, socket_id);
+	if (txq->sw_ring == NULL)
+		goto fail_sw_ring_alloc;
+
+	ctrl_txq = sfc_txq_by_dp_txq(&txq->dp);
+	if (ctrl_txq->evq->sa->tso) {
+		rc = sfc_efx_tso_alloc_tsoh_objs(txq->sw_ring,
+						 info->txq_entries, socket_id);
+		if (rc != 0)
+			goto fail_alloc_tsoh_objs;
+	}
+
+	txq->evq = ctrl_txq->evq;
+	txq->ptr_mask = info->txq_entries - 1;
+	txq->free_thresh = info->free_thresh;
+	txq->dma_desc_size_max = info->dma_desc_size_max;
+
+	*dp_txqp = &txq->dp;
+	return 0;
+
+fail_alloc_tsoh_objs:
+	rte_free(txq->sw_ring);
+
+fail_sw_ring_alloc:
+	rte_free(txq->pend_desc);
+
+fail_pend_desc_alloc:
+	rte_free(txq);
+
+fail_txq_alloc:
+	return rc;
+}
+
+static sfc_dp_tx_qdestroy_t sfc_efx_tx_qdestroy;
+static void
+sfc_efx_tx_qdestroy(struct sfc_dp_txq *dp_txq)
+{
+	struct sfc_efx_txq *txq = sfc_efx_txq_by_dp_txq(dp_txq);
+
+	sfc_efx_tso_free_tsoh_objs(txq->sw_ring, txq->ptr_mask + 1);
+	rte_free(txq->sw_ring);
+	rte_free(txq->pend_desc);
+	rte_free(txq);
+}
+
+static sfc_dp_tx_qstart_t sfc_efx_tx_qstart;
+static int
+sfc_efx_tx_qstart(struct sfc_dp_txq *dp_txq,
+		  __rte_unused unsigned int evq_read_ptr,
+		  unsigned int txq_desc_index)
+{
+	/* libefx-based datapath is specific to libefx-based PMD */
+	struct sfc_efx_txq *txq = sfc_efx_txq_by_dp_txq(dp_txq);
+	struct sfc_txq *ctrl_txq = sfc_txq_by_dp_txq(dp_txq);
+
+	txq->common = ctrl_txq->common;
+
+	txq->pending = txq->completed = txq->added = txq_desc_index;
+	txq->hw_vlan_tci = 0;
+
+	txq->flags |= (SFC_EFX_TXQ_FLAG_STARTED | SFC_EFX_TXQ_FLAG_RUNNING);
+
+	return 0;
+}
+
+static sfc_dp_tx_qstop_t sfc_efx_tx_qstop;
+static void
+sfc_efx_tx_qstop(struct sfc_dp_txq *dp_txq,
+		 __rte_unused unsigned int *evq_read_ptr)
+{
+	struct sfc_efx_txq *txq = sfc_efx_txq_by_dp_txq(dp_txq);
+
+	txq->flags &= ~SFC_EFX_TXQ_FLAG_RUNNING;
+}
+
+static sfc_dp_tx_qreap_t sfc_efx_tx_qreap;
+static void
+sfc_efx_tx_qreap(struct sfc_dp_txq *dp_txq)
+{
+	struct sfc_efx_txq *txq = sfc_efx_txq_by_dp_txq(dp_txq);
+	unsigned int txds;
+
+	sfc_efx_tx_reap(txq);
+
+	for (txds = 0; txds <= txq->ptr_mask; txds++) {
+		if (txq->sw_ring[txds].mbuf != NULL) {
+			rte_pktmbuf_free(txq->sw_ring[txds].mbuf);
+			txq->sw_ring[txds].mbuf = NULL;
+		}
+	}
+
+	txq->flags &= ~SFC_EFX_TXQ_FLAG_STARTED;
+}
+
+static sfc_dp_tx_qdesc_status_t sfc_efx_tx_qdesc_status;
+static int
+sfc_efx_tx_qdesc_status(struct sfc_dp_txq *dp_txq, uint16_t offset)
+{
+	struct sfc_efx_txq *txq = sfc_efx_txq_by_dp_txq(dp_txq);
+
+	if (unlikely(offset > txq->ptr_mask))
+		return -EINVAL;
+
+	if (unlikely(offset >= EFX_TXQ_LIMIT(txq->ptr_mask + 1)))
+		return RTE_ETH_TX_DESC_UNAVAIL;
+
+	/*
+	 * Poll EvQ to derive up-to-date 'txq->pending' figure;
+	 * it is required for the queue to be running, but the
+	 * check is omitted because API design assumes that it
+	 * is the duty of the caller to satisfy all conditions
+	 */
+	SFC_ASSERT((txq->flags & SFC_EFX_TXQ_FLAG_RUNNING) ==
+		   SFC_EFX_TXQ_FLAG_RUNNING);
+	sfc_ev_qpoll(txq->evq);
+
+	/*
+	 * Ring tail is 'txq->pending', and although descriptors
+	 * between 'txq->completed' and 'txq->pending' are still
+	 * in use by the driver, they should be reported as DONE
+	 */
+	if (unlikely(offset < (txq->added - txq->pending)))
+		return RTE_ETH_TX_DESC_FULL;
+
+	/*
+	 * There is no separate return value for unused descriptors;
+	 * the latter will be reported as DONE because genuine DONE
+	 * descriptors will be freed anyway in SW on the next burst
+	 */
+	return RTE_ETH_TX_DESC_DONE;
+}
+
+struct sfc_dp_tx sfc_efx_tx = {
+	.dp = {
+		.name		= SFC_KVARG_DATAPATH_EFX,
+		.type		= SFC_DP_TX,
+		.hw_fw_caps	= 0,
+	},
+	.features		= SFC_DP_TX_FEAT_VLAN_INSERT |
+				  SFC_DP_TX_FEAT_TSO |
+				  SFC_DP_TX_FEAT_MULTI_POOL |
+				  SFC_DP_TX_FEAT_REFCNT |
+				  SFC_DP_TX_FEAT_MULTI_SEG,
+	.qcreate		= sfc_efx_tx_qcreate,
+	.qdestroy		= sfc_efx_tx_qdestroy,
+	.qstart			= sfc_efx_tx_qstart,
+	.qstop			= sfc_efx_tx_qstop,
+	.qreap			= sfc_efx_tx_qreap,
+	.qdesc_status		= sfc_efx_tx_qdesc_status,
+	.pkt_burst		= sfc_efx_xmit_pkts,
+};