Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1237 insertions, 0 deletions

diff --git a/drivers/net/ethernet/mellanox/mlx4/en_tx.c b/drivers/net/ethernet/mellanox/mlx4/en_tx.c
new file mode 100644
index 0000000000..65cb63f6c4
--- /dev/null
+++ b/drivers/net/ethernet/mellanox/mlx4/en_tx.c
@@ -0,0 +1,1237 @@
+/*
+ * Copyright (c) 2007 Mellanox Technologies. All rights reserved.
+ *
+ * This software is available to you under a choice of one of two
+ * licenses.  You may choose to be licensed under the terms of the GNU
+ * General Public License (GPL) Version 2, available from the file
+ * COPYING in the main directory of this source tree, or the
+ * OpenIB.org BSD license below:
+ *
+ *     Redistribution and use in source and binary forms, with or
+ *     without modification, are permitted provided that the following
+ *     conditions are met:
+ *
+ *      - Redistributions of source code must retain the above
+ *        copyright notice, this list of conditions and the following
+ *        disclaimer.
+ *
+ *      - Redistributions in binary form must reproduce the above
+ *        copyright notice, this list of conditions and the following
+ *        disclaimer in the documentation and/or other materials
+ *        provided with the distribution.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ */
+
+#include <asm/page.h>
+#include <linux/mlx4/cq.h>
+#include <linux/slab.h>
+#include <linux/mlx4/qp.h>
+#include <linux/skbuff.h>
+#include <linux/if_vlan.h>
+#include <linux/prefetch.h>
+#include <linux/vmalloc.h>
+#include <linux/tcp.h>
+#include <linux/ip.h>
+#include <linux/ipv6.h>
+#include <linux/indirect_call_wrapper.h>
+#include <net/ipv6.h>
+
+#include "mlx4_en.h"
+
+int mlx4_en_create_tx_ring(struct mlx4_en_priv *priv,
+			   struct mlx4_en_tx_ring **pring, u32 size,
+			   u16 stride, int node, int queue_index)
+{
+	struct mlx4_en_dev *mdev = priv->mdev;
+	struct mlx4_en_tx_ring *ring;
+	int tmp;
+	int err;
+
+	ring = kzalloc_node(sizeof(*ring), GFP_KERNEL, node);
+	if (!ring) {
+		en_err(priv, "Failed allocating TX ring\n");
+		return -ENOMEM;
+	}
+
+	ring->size = size;
+	ring->size_mask = size - 1;
+	ring->sp_stride = stride;
+	ring->full_size = ring->size - HEADROOM - MLX4_MAX_DESC_TXBBS;
+
+	tmp = size * sizeof(struct mlx4_en_tx_info);
+	ring->tx_info = kvmalloc_node(tmp, GFP_KERNEL, node);
+	if (!ring->tx_info) {
+		err = -ENOMEM;
+		goto err_ring;
+	}
+
+	en_dbg(DRV, priv, "Allocated tx_info ring at addr:%p size:%d\n",
+		 ring->tx_info, tmp);
+
+	ring->bounce_buf = kmalloc_node(MLX4_TX_BOUNCE_BUFFER_SIZE,
+					GFP_KERNEL, node);
+	if (!ring->bounce_buf) {
+		ring->bounce_buf = kmalloc(MLX4_TX_BOUNCE_BUFFER_SIZE,
+					   GFP_KERNEL);
+		if (!ring->bounce_buf) {
+			err = -ENOMEM;
+			goto err_info;
+		}
+	}
+	ring->buf_size = ALIGN(size * ring->sp_stride, MLX4_EN_PAGE_SIZE);
+
+	/* Allocate HW buffers on provided NUMA node */
+	set_dev_node(&mdev->dev->persist->pdev->dev, node);
+	err = mlx4_alloc_hwq_res(mdev->dev, &ring->sp_wqres, ring->buf_size);
+	set_dev_node(&mdev->dev->persist->pdev->dev, mdev->dev->numa_node);
+	if (err) {
+		en_err(priv, "Failed allocating hwq resources\n");
+		goto err_bounce;
+	}
+
+	ring->buf = ring->sp_wqres.buf.direct.buf;
+
+	en_dbg(DRV, priv, "Allocated TX ring (addr:%p) - buf:%p size:%d buf_size:%d dma:%llx\n",
+	       ring, ring->buf, ring->size, ring->buf_size,
+	       (unsigned long long) ring->sp_wqres.buf.direct.map);
+
+	err = mlx4_qp_reserve_range(mdev->dev, 1, 1, &ring->qpn,
+				    MLX4_RESERVE_ETH_BF_QP,
+				    MLX4_RES_USAGE_DRIVER);
+	if (err) {
+		en_err(priv, "failed reserving qp for TX ring\n");
+		goto err_hwq_res;
+	}
+
+	err = mlx4_qp_alloc(mdev->dev, ring->qpn, &ring->sp_qp);
+	if (err) {
+		en_err(priv, "Failed allocating qp %d\n", ring->qpn);
+		goto err_reserve;
+	}
+	ring->sp_qp.event = mlx4_en_sqp_event;
+
+	err = mlx4_bf_alloc(mdev->dev, &ring->bf, node);
+	if (err) {
+		en_dbg(DRV, priv, "working without blueflame (%d)\n", err);
+		ring->bf.uar = &mdev->priv_uar;
+		ring->bf.uar->map = mdev->uar_map;
+		ring->bf_enabled = false;
+		ring->bf_alloced = false;
+		priv->pflags &= ~MLX4_EN_PRIV_FLAGS_BLUEFLAME;
+	} else {
+		ring->bf_alloced = true;
+		ring->bf_enabled = !!(priv->pflags &
+				      MLX4_EN_PRIV_FLAGS_BLUEFLAME);
+	}
+	ring->doorbell_address = ring->bf.uar->map + MLX4_SEND_DOORBELL;
+
+	ring->hwtstamp_tx_type = priv->hwtstamp_config.tx_type;
+	ring->queue_index = queue_index;
+
+	if (queue_index < priv->num_tx_rings_p_up)
+		cpumask_set_cpu(cpumask_local_spread(queue_index,
+						     priv->mdev->dev->numa_node),
+				&ring->sp_affinity_mask);
+
+	*pring = ring;
+	return 0;
+
+err_reserve:
+	mlx4_qp_release_range(mdev->dev, ring->qpn, 1);
+err_hwq_res:
+	mlx4_free_hwq_res(mdev->dev, &ring->sp_wqres, ring->buf_size);
+err_bounce:
+	kfree(ring->bounce_buf);
+	ring->bounce_buf = NULL;
+err_info:
+	kvfree(ring->tx_info);
+	ring->tx_info = NULL;
+err_ring:
+	kfree(ring);
+	*pring = NULL;
+	return err;
+}
+
+void mlx4_en_destroy_tx_ring(struct mlx4_en_priv *priv,
+			     struct mlx4_en_tx_ring **pring)
+{
+	struct mlx4_en_dev *mdev = priv->mdev;
+	struct mlx4_en_tx_ring *ring = *pring;
+	en_dbg(DRV, priv, "Destroying tx ring, qpn: %d\n", ring->qpn);
+
+	if (ring->bf_alloced)
+		mlx4_bf_free(mdev->dev, &ring->bf);
+	mlx4_qp_remove(mdev->dev, &ring->sp_qp);
+	mlx4_qp_free(mdev->dev, &ring->sp_qp);
+	mlx4_qp_release_range(priv->mdev->dev, ring->qpn, 1);
+	mlx4_free_hwq_res(mdev->dev, &ring->sp_wqres, ring->buf_size);
+	kfree(ring->bounce_buf);
+	ring->bounce_buf = NULL;
+	kvfree(ring->tx_info);
+	ring->tx_info = NULL;
+	kfree(ring);
+	*pring = NULL;
+}
+
+int mlx4_en_activate_tx_ring(struct mlx4_en_priv *priv,
+			     struct mlx4_en_tx_ring *ring,
+			     int cq, int user_prio)
+{
+	struct mlx4_en_dev *mdev = priv->mdev;
+	int err;
+
+	ring->sp_cqn = cq;
+	ring->prod = 0;
+	ring->cons = 0xffffffff;
+	ring->last_nr_txbb = 1;
+	memset(ring->tx_info, 0, ring->size * sizeof(struct mlx4_en_tx_info));
+	memset(ring->buf, 0, ring->buf_size);
+	ring->free_tx_desc = mlx4_en_free_tx_desc;
+
+	ring->sp_qp_state = MLX4_QP_STATE_RST;
+	ring->doorbell_qpn = cpu_to_be32(ring->sp_qp.qpn << 8);
+	ring->mr_key = cpu_to_be32(mdev->mr.key);
+
+	mlx4_en_fill_qp_context(priv, ring->size, ring->sp_stride, 1, 0, ring->qpn,
+				ring->sp_cqn, user_prio, &ring->sp_context);
+	if (ring->bf_alloced)
+		ring->sp_context.usr_page =
+			cpu_to_be32(mlx4_to_hw_uar_index(mdev->dev,
+							 ring->bf.uar->index));
+
+	err = mlx4_qp_to_ready(mdev->dev, &ring->sp_wqres.mtt, &ring->sp_context,
+			       &ring->sp_qp, &ring->sp_qp_state);
+	if (!cpumask_empty(&ring->sp_affinity_mask))
+		netif_set_xps_queue(priv->dev, &ring->sp_affinity_mask,
+				    ring->queue_index);
+
+	return err;
+}
+
+void mlx4_en_deactivate_tx_ring(struct mlx4_en_priv *priv,
+				struct mlx4_en_tx_ring *ring)
+{
+	struct mlx4_en_dev *mdev = priv->mdev;
+
+	mlx4_qp_modify(mdev->dev, NULL, ring->sp_qp_state,
+		       MLX4_QP_STATE_RST, NULL, 0, 0, &ring->sp_qp);
+}
+
+static inline bool mlx4_en_is_tx_ring_full(struct mlx4_en_tx_ring *ring)
+{
+	u32 used = READ_ONCE(ring->prod) - READ_ONCE(ring->cons);
+
+	return used > ring->full_size;
+}
+
+static void mlx4_en_stamp_wqe(struct mlx4_en_priv *priv,
+			      struct mlx4_en_tx_ring *ring, int index,
+			      u8 owner)
+{
+	__be32 stamp = cpu_to_be32(STAMP_VAL | (!!owner << STAMP_SHIFT));
+	struct mlx4_en_tx_desc *tx_desc = ring->buf + (index << LOG_TXBB_SIZE);
+	struct mlx4_en_tx_info *tx_info = &ring->tx_info[index];
+	void *end = ring->buf + ring->buf_size;
+	__be32 *ptr = (__be32 *)tx_desc;
+	int i;
+
+	/* Optimize the common case when there are no wraparounds */
+	if (likely((void *)tx_desc +
+		   (tx_info->nr_txbb << LOG_TXBB_SIZE) <= end)) {
+		/* Stamp the freed descriptor */
+		for (i = 0; i < tx_info->nr_txbb << LOG_TXBB_SIZE;
+		     i += STAMP_STRIDE) {
+			*ptr = stamp;
+			ptr += STAMP_DWORDS;
+		}
+	} else {
+		/* Stamp the freed descriptor */
+		for (i = 0; i < tx_info->nr_txbb << LOG_TXBB_SIZE;
+		     i += STAMP_STRIDE) {
+			*ptr = stamp;
+			ptr += STAMP_DWORDS;
+			if ((void *)ptr >= end) {
+				ptr = ring->buf;
+				stamp ^= cpu_to_be32(0x80000000);
+			}
+		}
+	}
+}
+
+INDIRECT_CALLABLE_DECLARE(u32 mlx4_en_free_tx_desc(struct mlx4_en_priv *priv,
+						   struct mlx4_en_tx_ring *ring,
+						   int index, u64 timestamp,
+						   int napi_mode));
+
+u32 mlx4_en_free_tx_desc(struct mlx4_en_priv *priv,
+			 struct mlx4_en_tx_ring *ring,
+			 int index, u64 timestamp,
+			 int napi_mode)
+{
+	struct mlx4_en_tx_info *tx_info = &ring->tx_info[index];
+	struct mlx4_en_tx_desc *tx_desc = ring->buf + (index << LOG_TXBB_SIZE);
+	struct mlx4_wqe_data_seg *data = (void *) tx_desc + tx_info->data_offset;
+	void *end = ring->buf + ring->buf_size;
+	struct sk_buff *skb = tx_info->skb;
+	int nr_maps = tx_info->nr_maps;
+	int i;
+
+	/* We do not touch skb here, so prefetch skb->users location
+	 * to speedup consume_skb()
+	 */
+	prefetchw(&skb->users);
+
+	if (unlikely(timestamp)) {
+		struct skb_shared_hwtstamps hwts;
+
+		mlx4_en_fill_hwtstamps(priv->mdev, &hwts, timestamp);
+		skb_tstamp_tx(skb, &hwts);
+	}
+
+	if (!tx_info->inl) {
+		if (tx_info->linear)
+			dma_unmap_single(priv->ddev,
+					 tx_info->map0_dma,
+					 tx_info->map0_byte_count,
+					 DMA_TO_DEVICE);
+		else
+			dma_unmap_page(priv->ddev,
+				       tx_info->map0_dma,
+				       tx_info->map0_byte_count,
+				       DMA_TO_DEVICE);
+		/* Optimize the common case when there are no wraparounds */
+		if (likely((void *)tx_desc +
+			   (tx_info->nr_txbb << LOG_TXBB_SIZE) <= end)) {
+			for (i = 1; i < nr_maps; i++) {
+				data++;
+				dma_unmap_page(priv->ddev,
+					(dma_addr_t)be64_to_cpu(data->addr),
+					be32_to_cpu(data->byte_count),
+					DMA_TO_DEVICE);
+			}
+		} else {
+			if ((void *)data >= end)
+				data = ring->buf + ((void *)data - end);
+
+			for (i = 1; i < nr_maps; i++) {
+				data++;
+				/* Check for wraparound before unmapping */
+				if ((void *) data >= end)
+					data = ring->buf;
+				dma_unmap_page(priv->ddev,
+					(dma_addr_t)be64_to_cpu(data->addr),
+					be32_to_cpu(data->byte_count),
+					DMA_TO_DEVICE);
+			}
+		}
+	}
+	napi_consume_skb(skb, napi_mode);
+
+	return tx_info->nr_txbb;
+}
+
+INDIRECT_CALLABLE_DECLARE(u32 mlx4_en_recycle_tx_desc(struct mlx4_en_priv *priv,
+						      struct mlx4_en_tx_ring *ring,
+						      int index, u64 timestamp,
+						      int napi_mode));
+
+u32 mlx4_en_recycle_tx_desc(struct mlx4_en_priv *priv,
+			    struct mlx4_en_tx_ring *ring,
+			    int index, u64 timestamp,
+			    int napi_mode)
+{
+	struct mlx4_en_tx_info *tx_info = &ring->tx_info[index];
+	struct mlx4_en_rx_alloc frame = {
+		.page = tx_info->page,
+		.dma = tx_info->map0_dma,
+	};
+
+	if (!napi_mode || !mlx4_en_rx_recycle(ring->recycle_ring, &frame)) {
+		dma_unmap_page(priv->ddev, tx_info->map0_dma,
+			       PAGE_SIZE, priv->dma_dir);
+		put_page(tx_info->page);
+	}
+
+	return tx_info->nr_txbb;
+}
+
+int mlx4_en_free_tx_buf(struct net_device *dev, struct mlx4_en_tx_ring *ring)
+{
+	struct mlx4_en_priv *priv = netdev_priv(dev);
+	int cnt = 0;
+
+	/* Skip last polled descriptor */
+	ring->cons += ring->last_nr_txbb;
+	en_dbg(DRV, priv, "Freeing Tx buf - cons:0x%x prod:0x%x\n",
+		 ring->cons, ring->prod);
+
+	if ((u32) (ring->prod - ring->cons) > ring->size) {
+		if (netif_msg_tx_err(priv))
+			en_warn(priv, "Tx consumer passed producer!\n");
+		return 0;
+	}
+
+	while (ring->cons != ring->prod) {
+		ring->last_nr_txbb = ring->free_tx_desc(priv, ring,
+						ring->cons & ring->size_mask,
+						0, 0 /* Non-NAPI caller */);
+		ring->cons += ring->last_nr_txbb;
+		cnt++;
+	}
+
+	if (ring->tx_queue)
+		netdev_tx_reset_queue(ring->tx_queue);
+
+	if (cnt)
+		en_dbg(DRV, priv, "Freed %d uncompleted tx descriptors\n", cnt);
+
+	return cnt;
+}
+
+static void mlx4_en_handle_err_cqe(struct mlx4_en_priv *priv, struct mlx4_err_cqe *err_cqe,
+				   u16 cqe_index, struct mlx4_en_tx_ring *ring)
+{
+	struct mlx4_en_dev *mdev = priv->mdev;
+	struct mlx4_en_tx_info *tx_info;
+	struct mlx4_en_tx_desc *tx_desc;
+	u16 wqe_index;
+	int desc_size;
+
+	en_err(priv, "CQE error - cqn 0x%x, ci 0x%x, vendor syndrome: 0x%x syndrome: 0x%x\n",
+	       ring->sp_cqn, cqe_index, err_cqe->vendor_err_syndrome, err_cqe->syndrome);
+	print_hex_dump(KERN_WARNING, "", DUMP_PREFIX_OFFSET, 16, 1, err_cqe, sizeof(*err_cqe),
+		       false);
+
+	wqe_index = be16_to_cpu(err_cqe->wqe_index) & ring->size_mask;
+	tx_info = &ring->tx_info[wqe_index];
+	desc_size = tx_info->nr_txbb << LOG_TXBB_SIZE;
+	en_err(priv, "Related WQE - qpn 0x%x, wqe index 0x%x, wqe size 0x%x\n", ring->qpn,
+	       wqe_index, desc_size);
+	tx_desc = ring->buf + (wqe_index << LOG_TXBB_SIZE);
+	print_hex_dump(KERN_WARNING, "", DUMP_PREFIX_OFFSET, 16, 1, tx_desc, desc_size, false);
+
+	if (test_and_set_bit(MLX4_EN_STATE_FLAG_RESTARTING, &priv->state))
+		return;
+
+	en_err(priv, "Scheduling port restart\n");
+	queue_work(mdev->workqueue, &priv->restart_task);
+}
+
+int mlx4_en_process_tx_cq(struct net_device *dev,
+			  struct mlx4_en_cq *cq, int napi_budget)
+{
+	struct mlx4_en_priv *priv = netdev_priv(dev);
+	struct mlx4_cq *mcq = &cq->mcq;
+	struct mlx4_en_tx_ring *ring = priv->tx_ring[cq->type][cq->ring];
+	struct mlx4_cqe *cqe;
+	u16 index, ring_index, stamp_index;
+	u32 txbbs_skipped = 0;
+	u32 txbbs_stamp = 0;
+	u32 cons_index = mcq->cons_index;
+	int size = cq->size;
+	u32 size_mask = ring->size_mask;
+	struct mlx4_cqe *buf = cq->buf;
+	u32 packets = 0;
+	u32 bytes = 0;
+	int factor = priv->cqe_factor;
+	int done = 0;
+	int budget = priv->tx_work_limit;
+	u32 last_nr_txbb;
+	u32 ring_cons;
+
+	if (unlikely(!priv->port_up))
+		return 0;
+
+	netdev_txq_bql_complete_prefetchw(ring->tx_queue);
+
+	index = cons_index & size_mask;
+	cqe = mlx4_en_get_cqe(buf, index, priv->cqe_size) + factor;
+	last_nr_txbb = READ_ONCE(ring->last_nr_txbb);
+	ring_cons = READ_ONCE(ring->cons);
+	ring_index = ring_cons & size_mask;
+	stamp_index = ring_index;
+
+	/* Process all completed CQEs */
+	while (XNOR(cqe->owner_sr_opcode & MLX4_CQE_OWNER_MASK,
+			cons_index & size) && (done < budget)) {
+		u16 new_index;
+
+		/*
+		 * make sure we read the CQE after we read the
+		 * ownership bit
+		 */
+		dma_rmb();
+
+		if (unlikely((cqe->owner_sr_opcode & MLX4_CQE_OPCODE_MASK) ==
+			     MLX4_CQE_OPCODE_ERROR))
+			if (!test_and_set_bit(MLX4_EN_TX_RING_STATE_RECOVERING, &ring->state))
+				mlx4_en_handle_err_cqe(priv, (struct mlx4_err_cqe *)cqe, index,
+						       ring);
+
+		/* Skip over last polled CQE */
+		new_index = be16_to_cpu(cqe->wqe_index) & size_mask;
+
+		do {
+			u64 timestamp = 0;
+
+			txbbs_skipped += last_nr_txbb;
+			ring_index = (ring_index + last_nr_txbb) & size_mask;
+
+			if (unlikely(ring->tx_info[ring_index].ts_requested))
+				timestamp = mlx4_en_get_cqe_ts(cqe);
+
+			/* free next descriptor */
+			last_nr_txbb = INDIRECT_CALL_2(ring->free_tx_desc,
+						       mlx4_en_free_tx_desc,
+						       mlx4_en_recycle_tx_desc,
+					priv, ring, ring_index,
+					timestamp, napi_budget);
+
+			mlx4_en_stamp_wqe(priv, ring, stamp_index,
+					  !!((ring_cons + txbbs_stamp) &
+						ring->size));
+			stamp_index = ring_index;
+			txbbs_stamp = txbbs_skipped;
+			packets++;
+			bytes += ring->tx_info[ring_index].nr_bytes;
+		} while ((++done < budget) && (ring_index != new_index));
+
+		++cons_index;
+		index = cons_index & size_mask;
+		cqe = mlx4_en_get_cqe(buf, index, priv->cqe_size) + factor;
+	}
+
+	/*
+	 * To prevent CQ overflow we first update CQ consumer and only then
+	 * the ring consumer.
+	 */
+	mcq->cons_index = cons_index;
+	mlx4_cq_set_ci(mcq);
+	wmb();
+
+	/* we want to dirty this cache line once */
+	WRITE_ONCE(ring->last_nr_txbb, last_nr_txbb);
+	WRITE_ONCE(ring->cons, ring_cons + txbbs_skipped);
+
+	if (cq->type == TX_XDP)
+		return done;
+
+	netdev_tx_completed_queue(ring->tx_queue, packets, bytes);
+
+	/* Wakeup Tx queue if this stopped, and ring is not full.
+	 */
+	if (netif_tx_queue_stopped(ring->tx_queue) &&
+	    !mlx4_en_is_tx_ring_full(ring)) {
+		netif_tx_wake_queue(ring->tx_queue);
+		ring->wake_queue++;
+	}
+
+	return done;
+}
+
+void mlx4_en_tx_irq(struct mlx4_cq *mcq)
+{
+	struct mlx4_en_cq *cq = container_of(mcq, struct mlx4_en_cq, mcq);
+	struct mlx4_en_priv *priv = netdev_priv(cq->dev);
+
+	if (likely(priv->port_up))
+		napi_schedule_irqoff(&cq->napi);
+	else
+		mlx4_en_arm_cq(priv, cq);
+}
+
+/* TX CQ polling - called by NAPI */
+int mlx4_en_poll_tx_cq(struct napi_struct *napi, int budget)
+{
+	struct mlx4_en_cq *cq = container_of(napi, struct mlx4_en_cq, napi);
+	struct net_device *dev = cq->dev;
+	struct mlx4_en_priv *priv = netdev_priv(dev);
+	int work_done;
+
+	work_done = mlx4_en_process_tx_cq(dev, cq, budget);
+	if (work_done >= budget)
+		return budget;
+
+	if (napi_complete_done(napi, work_done))
+		mlx4_en_arm_cq(priv, cq);
+
+	return 0;
+}
+
+static struct mlx4_en_tx_desc *mlx4_en_bounce_to_desc(struct mlx4_en_priv *priv,
+						      struct mlx4_en_tx_ring *ring,
+						      u32 index,
+						      unsigned int desc_size)
+{
+	u32 copy = (ring->size - index) << LOG_TXBB_SIZE;
+	int i;
+
+	for (i = desc_size - copy - 4; i >= 0; i -= 4) {
+		if ((i & (TXBB_SIZE - 1)) == 0)
+			wmb();
+
+		*((u32 *) (ring->buf + i)) =
+			*((u32 *) (ring->bounce_buf + copy + i));
+	}
+
+	for (i = copy - 4; i >= 4 ; i -= 4) {
+		if ((i & (TXBB_SIZE - 1)) == 0)
+			wmb();
+
+		*((u32 *)(ring->buf + (index << LOG_TXBB_SIZE) + i)) =
+			*((u32 *) (ring->bounce_buf + i));
+	}
+
+	/* Return real descriptor location */
+	return ring->buf + (index << LOG_TXBB_SIZE);
+}
+
+/* Decide if skb can be inlined in tx descriptor to avoid dma mapping
+ *
+ * It seems strange we do not simply use skb_copy_bits().
+ * This would allow to inline all skbs iff skb->len <= inline_thold
+ *
+ * Note that caller already checked skb was not a gso packet
+ */
+static bool is_inline(int inline_thold, const struct sk_buff *skb,
+		      const struct skb_shared_info *shinfo,
+		      void **pfrag)
+{
+	void *ptr;
+
+	if (skb->len > inline_thold || !inline_thold)
+		return false;
+
+	if (shinfo->nr_frags == 1) {
+		ptr = skb_frag_address_safe(&shinfo->frags[0]);
+		if (unlikely(!ptr))
+			return false;
+		*pfrag = ptr;
+		return true;
+	}
+	if (shinfo->nr_frags)
+		return false;
+	return true;
+}
+
+static int inline_size(const struct sk_buff *skb)
+{
+	if (skb->len + CTRL_SIZE + sizeof(struct mlx4_wqe_inline_seg)
+	    <= MLX4_INLINE_ALIGN)
+		return ALIGN(skb->len + CTRL_SIZE +
+			     sizeof(struct mlx4_wqe_inline_seg), 16);
+	else
+		return ALIGN(skb->len + CTRL_SIZE + 2 *
+			     sizeof(struct mlx4_wqe_inline_seg), 16);
+}
+
+static int get_real_size(const struct sk_buff *skb,
+			 const struct skb_shared_info *shinfo,
+			 struct net_device *dev,
+			 int *lso_header_size,
+			 bool *inline_ok,
+			 void **pfrag,
+			 int *hopbyhop)
+{
+	struct mlx4_en_priv *priv = netdev_priv(dev);
+	int real_size;
+
+	if (shinfo->gso_size) {
+		*inline_ok = false;
+		*hopbyhop = 0;
+		if (skb->encapsulation) {
+			*lso_header_size = skb_inner_tcp_all_headers(skb);
+		} else {
+			/* Detects large IPV6 TCP packets and prepares for removal of
+			 * HBH header that has been pushed by ip6_xmit(),
+			 * mainly so that tcpdump can dissect them.
+			 */
+			if (ipv6_has_hopopt_jumbo(skb))
+				*hopbyhop = sizeof(struct hop_jumbo_hdr);
+			*lso_header_size = skb_tcp_all_headers(skb);
+		}
+		real_size = CTRL_SIZE + shinfo->nr_frags * DS_SIZE +
+			ALIGN(*lso_header_size - *hopbyhop + 4, DS_SIZE);
+		if (unlikely(*lso_header_size != skb_headlen(skb))) {
+			/* We add a segment for the skb linear buffer only if
+			 * it contains data */
+			if (*lso_header_size < skb_headlen(skb))
+				real_size += DS_SIZE;
+			else {
+				if (netif_msg_tx_err(priv))
+					en_warn(priv, "Non-linear headers\n");
+				return 0;
+			}
+		}
+	} else {
+		*lso_header_size = 0;
+		*inline_ok = is_inline(priv->prof->inline_thold, skb,
+				       shinfo, pfrag);
+
+		if (*inline_ok)
+			real_size = inline_size(skb);
+		else
+			real_size = CTRL_SIZE +
+				    (shinfo->nr_frags + 1) * DS_SIZE;
+	}
+
+	return real_size;
+}
+
+static void build_inline_wqe(struct mlx4_en_tx_desc *tx_desc,
+			     const struct sk_buff *skb,
+			     const struct skb_shared_info *shinfo,
+			     void *fragptr)
+{
+	struct mlx4_wqe_inline_seg *inl = &tx_desc->inl;
+	int spc = MLX4_INLINE_ALIGN - CTRL_SIZE - sizeof(*inl);
+	unsigned int hlen = skb_headlen(skb);
+
+	if (skb->len <= spc) {
+		if (likely(skb->len >= MIN_PKT_LEN)) {
+			inl->byte_count = cpu_to_be32(1 << 31 | skb->len);
+		} else {
+			inl->byte_count = cpu_to_be32(1 << 31 | MIN_PKT_LEN);
+			memset(inl->data + skb->len, 0,
+			       MIN_PKT_LEN - skb->len);
+		}
+		skb_copy_from_linear_data(skb, inl->data, hlen);
+		if (shinfo->nr_frags)
+			memcpy(inl->data + hlen, fragptr,
+			       skb_frag_size(&shinfo->frags[0]));
+
+	} else {
+		inl->byte_count = cpu_to_be32(1 << 31 | spc);
+		if (hlen <= spc) {
+			skb_copy_from_linear_data(skb, inl->data, hlen);
+			if (hlen < spc) {
+				memcpy(inl->data + hlen,
+				       fragptr, spc - hlen);
+				fragptr +=  spc - hlen;
+			}
+			inl = (void *)inl->data + spc;
+			memcpy(inl->data, fragptr, skb->len - spc);
+		} else {
+			skb_copy_from_linear_data(skb, inl->data, spc);
+			inl = (void *)inl->data + spc;
+			skb_copy_from_linear_data_offset(skb, spc, inl->data,
+							 hlen - spc);
+			if (shinfo->nr_frags)
+				memcpy(inl->data + hlen - spc,
+				       fragptr,
+				       skb_frag_size(&shinfo->frags[0]));
+		}
+
+		dma_wmb();
+		inl->byte_count = cpu_to_be32(1 << 31 | (skb->len - spc));
+	}
+}
+
+u16 mlx4_en_select_queue(struct net_device *dev, struct sk_buff *skb,
+			 struct net_device *sb_dev)
+{
+	struct mlx4_en_priv *priv = netdev_priv(dev);
+	u16 rings_p_up = priv->num_tx_rings_p_up;
+
+	if (netdev_get_num_tc(dev))
+		return netdev_pick_tx(dev, skb, NULL);
+
+	return netdev_pick_tx(dev, skb, NULL) % rings_p_up;
+}
+
+static void mlx4_bf_copy(void __iomem *dst, const void *src,
+			 unsigned int bytecnt)
+{
+	__iowrite64_copy(dst, src, bytecnt / 8);
+}
+
+void mlx4_en_xmit_doorbell(struct mlx4_en_tx_ring *ring)
+{
+	wmb();
+	/* Since there is no iowrite*_native() that writes the
+	 * value as is, without byteswapping - using the one
+	 * the doesn't do byteswapping in the relevant arch
+	 * endianness.
+	 */
+#if defined(__LITTLE_ENDIAN)
+	iowrite32(
+#else
+	iowrite32be(
+#endif
+		  (__force u32)ring->doorbell_qpn, ring->doorbell_address);
+}
+
+static void mlx4_en_tx_write_desc(struct mlx4_en_tx_ring *ring,
+				  struct mlx4_en_tx_desc *tx_desc,
+				  union mlx4_wqe_qpn_vlan qpn_vlan,
+				  int desc_size, int bf_index,
+				  __be32 op_own, bool bf_ok,
+				  bool send_doorbell)
+{
+	tx_desc->ctrl.qpn_vlan = qpn_vlan;
+
+	if (bf_ok) {
+		op_own |= htonl((bf_index & 0xffff) << 8);
+		/* Ensure new descriptor hits memory
+		 * before setting ownership of this descriptor to HW
+		 */
+		dma_wmb();
+		tx_desc->ctrl.owner_opcode = op_own;
+
+		wmb();
+
+		mlx4_bf_copy(ring->bf.reg + ring->bf.offset, &tx_desc->ctrl,
+			     desc_size);
+
+		wmb();
+
+		ring->bf.offset ^= ring->bf.buf_size;
+	} else {
+		/* Ensure new descriptor hits memory
+		 * before setting ownership of this descriptor to HW
+		 */
+		dma_wmb();
+		tx_desc->ctrl.owner_opcode = op_own;
+		if (send_doorbell)
+			mlx4_en_xmit_doorbell(ring);
+		else
+			ring->xmit_more++;
+	}
+}
+
+static bool mlx4_en_build_dma_wqe(struct mlx4_en_priv *priv,
+				  struct skb_shared_info *shinfo,
+				  struct mlx4_wqe_data_seg *data,
+				  struct sk_buff *skb,
+				  int lso_header_size,
+				  __be32 mr_key,
+				  struct mlx4_en_tx_info *tx_info)
+{
+	struct device *ddev = priv->ddev;
+	dma_addr_t dma = 0;
+	u32 byte_count = 0;
+	int i_frag;
+
+	/* Map fragments if any */
+	for (i_frag = shinfo->nr_frags - 1; i_frag >= 0; i_frag--) {
+		const skb_frag_t *frag = &shinfo->frags[i_frag];
+		byte_count = skb_frag_size(frag);
+		dma = skb_frag_dma_map(ddev, frag,
+				       0, byte_count,
+				       DMA_TO_DEVICE);
+		if (dma_mapping_error(ddev, dma))
+			goto tx_drop_unmap;
+
+		data->addr = cpu_to_be64(dma);
+		data->lkey = mr_key;
+		dma_wmb();
+		data->byte_count = cpu_to_be32(byte_count);
+		--data;
+	}
+
+	/* Map linear part if needed */
+	if (tx_info->linear) {
+		byte_count = skb_headlen(skb) - lso_header_size;
+
+		dma = dma_map_single(ddev, skb->data +
+				     lso_header_size, byte_count,
+				     DMA_TO_DEVICE);
+		if (dma_mapping_error(ddev, dma))
+			goto tx_drop_unmap;
+
+		data->addr = cpu_to_be64(dma);
+		data->lkey = mr_key;
+		dma_wmb();
+		data->byte_count = cpu_to_be32(byte_count);
+	}
+	/* tx completion can avoid cache line miss for common cases */
+	tx_info->map0_dma = dma;
+	tx_info->map0_byte_count = byte_count;
+
+	return true;
+
+tx_drop_unmap:
+	en_err(priv, "DMA mapping error\n");
+
+	while (++i_frag < shinfo->nr_frags) {
+		++data;
+		dma_unmap_page(ddev, (dma_addr_t)be64_to_cpu(data->addr),
+			       be32_to_cpu(data->byte_count),
+			       DMA_TO_DEVICE);
+	}
+
+	return false;
+}
+
+netdev_tx_t mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+	struct skb_shared_info *shinfo = skb_shinfo(skb);
+	struct mlx4_en_priv *priv = netdev_priv(dev);
+	union mlx4_wqe_qpn_vlan	qpn_vlan = {};
+	struct mlx4_en_tx_ring *ring;
+	struct mlx4_en_tx_desc *tx_desc;
+	struct mlx4_wqe_data_seg *data;
+	struct mlx4_en_tx_info *tx_info;
+	u32 __maybe_unused ring_cons;
+	int tx_ind;
+	int nr_txbb;
+	int desc_size;
+	int real_size;
+	u32 index, bf_index;
+	struct ipv6hdr *h6;
+	__be32 op_own;
+	int lso_header_size;
+	void *fragptr = NULL;
+	bool bounce = false;
+	bool send_doorbell;
+	bool stop_queue;
+	bool inline_ok;
+	u8 data_offset;
+	int hopbyhop;
+	bool bf_ok;
+
+	tx_ind = skb_get_queue_mapping(skb);
+	ring = priv->tx_ring[TX][tx_ind];
+
+	if (unlikely(!priv->port_up))
+		goto tx_drop;
+
+	real_size = get_real_size(skb, shinfo, dev, &lso_header_size,
+				  &inline_ok, &fragptr, &hopbyhop);
+	if (unlikely(!real_size))
+		goto tx_drop_count;
+
+	/* Align descriptor to TXBB size */
+	desc_size = ALIGN(real_size, TXBB_SIZE);
+	nr_txbb = desc_size >> LOG_TXBB_SIZE;
+
+	bf_ok = ring->bf_enabled;
+	if (skb_vlan_tag_present(skb)) {
+		u16 vlan_proto;
+
+		qpn_vlan.vlan_tag = cpu_to_be16(skb_vlan_tag_get(skb));
+		vlan_proto = be16_to_cpu(skb->vlan_proto);
+		if (vlan_proto == ETH_P_8021AD)
+			qpn_vlan.ins_vlan = MLX4_WQE_CTRL_INS_SVLAN;
+		else if (vlan_proto == ETH_P_8021Q)
+			qpn_vlan.ins_vlan = MLX4_WQE_CTRL_INS_CVLAN;
+		else
+			qpn_vlan.ins_vlan = 0;
+		bf_ok = false;
+	}
+
+	netdev_txq_bql_enqueue_prefetchw(ring->tx_queue);
+
+	/* Packet is good - grab an index and transmit it */
+	index = ring->prod & ring->size_mask;
+	bf_index = ring->prod;
+
+	/* See if we have enough space for whole descriptor TXBB for setting
+	 * SW ownership on next descriptor; if not, use a bounce buffer. */
+	if (likely(index + nr_txbb <= ring->size))
+		tx_desc = ring->buf + (index << LOG_TXBB_SIZE);
+	else {
+		if (unlikely(nr_txbb > MLX4_MAX_DESC_TXBBS)) {
+			if (netif_msg_tx_err(priv))
+				en_warn(priv, "Oversized header or SG list\n");
+			goto tx_drop_count;
+		}
+		tx_desc = (struct mlx4_en_tx_desc *) ring->bounce_buf;
+		bounce = true;
+		bf_ok = false;
+	}
+
+	/* Save skb in tx_info ring */
+	tx_info = &ring->tx_info[index];
+	tx_info->skb = skb;
+	tx_info->nr_txbb = nr_txbb;
+
+	if (!lso_header_size) {
+		data = &tx_desc->data;
+		data_offset = offsetof(struct mlx4_en_tx_desc, data);
+	} else {
+		int lso_align = ALIGN(lso_header_size - hopbyhop + 4, DS_SIZE);
+
+		data = (void *)&tx_desc->lso + lso_align;
+		data_offset = offsetof(struct mlx4_en_tx_desc, lso) + lso_align;
+	}
+
+	/* valid only for none inline segments */
+	tx_info->data_offset = data_offset;
+
+	tx_info->inl = inline_ok;
+
+	tx_info->linear = lso_header_size < skb_headlen(skb) && !inline_ok;
+
+	tx_info->nr_maps = shinfo->nr_frags + tx_info->linear;
+	data += tx_info->nr_maps - 1;
+
+	if (!tx_info->inl)
+		if (!mlx4_en_build_dma_wqe(priv, shinfo, data, skb,
+					   lso_header_size, ring->mr_key,
+					   tx_info))
+			goto tx_drop_count;
+
+	/*
+	 * For timestamping add flag to skb_shinfo and
+	 * set flag for further reference
+	 */
+	tx_info->ts_requested = 0;
+	if (unlikely(ring->hwtstamp_tx_type == HWTSTAMP_TX_ON &&
+		     shinfo->tx_flags & SKBTX_HW_TSTAMP)) {
+		shinfo->tx_flags |= SKBTX_IN_PROGRESS;
+		tx_info->ts_requested = 1;
+	}
+
+	/* Prepare ctrl segement apart opcode+ownership, which depends on
+	 * whether LSO is used */
+	tx_desc->ctrl.srcrb_flags = priv->ctrl_flags;
+	if (likely(skb->ip_summed == CHECKSUM_PARTIAL)) {
+		if (!skb->encapsulation)
+			tx_desc->ctrl.srcrb_flags |= cpu_to_be32(MLX4_WQE_CTRL_IP_CSUM |
+								 MLX4_WQE_CTRL_TCP_UDP_CSUM);
+		else
+			tx_desc->ctrl.srcrb_flags |= cpu_to_be32(MLX4_WQE_CTRL_IP_CSUM);
+		ring->tx_csum++;
+	}
+
+	if (priv->flags & MLX4_EN_FLAG_ENABLE_HW_LOOPBACK) {
+		struct ethhdr *ethh;
+
+		/* Copy dst mac address to wqe. This allows loopback in eSwitch,
+		 * so that VFs and PF can communicate with each other
+		 */
+		ethh = (struct ethhdr *)skb->data;
+		tx_desc->ctrl.srcrb_flags16[0] = get_unaligned((__be16 *)ethh->h_dest);
+		tx_desc->ctrl.imm = get_unaligned((__be32 *)(ethh->h_dest + 2));
+	}
+
+	/* Handle LSO (TSO) packets */
+	if (lso_header_size) {
+		int i;
+
+		/* Mark opcode as LSO */
+		op_own = cpu_to_be32(MLX4_OPCODE_LSO | (1 << 6)) |
+			((ring->prod & ring->size) ?
+				cpu_to_be32(MLX4_EN_BIT_DESC_OWN) : 0);
+
+		lso_header_size -= hopbyhop;
+		/* Fill in the LSO prefix */
+		tx_desc->lso.mss_hdr_size = cpu_to_be32(
+			shinfo->gso_size << 16 | lso_header_size);
+
+
+		if (unlikely(hopbyhop)) {
+			/* remove the HBH header.
+			 * Layout: [Ethernet header][IPv6 header][HBH][TCP header]
+			 */
+			memcpy(tx_desc->lso.header, skb->data, ETH_HLEN + sizeof(*h6));
+			h6 = (struct ipv6hdr *)((char *)tx_desc->lso.header + ETH_HLEN);
+			h6->nexthdr = IPPROTO_TCP;
+			/* Copy the TCP header after the IPv6 one */
+			memcpy(h6 + 1,
+			       skb->data + ETH_HLEN + sizeof(*h6) +
+					sizeof(struct hop_jumbo_hdr),
+			       tcp_hdrlen(skb));
+			/* Leave ipv6 payload_len set to 0, as LSO v2 specs request. */
+		} else {
+			/* Copy headers;
+			 * note that we already verified that it is linear
+			 */
+			memcpy(tx_desc->lso.header, skb->data, lso_header_size);
+		}
+		ring->tso_packets++;
+
+		i = shinfo->gso_segs;
+		tx_info->nr_bytes = skb->len + (i - 1) * lso_header_size;
+		ring->packets += i;
+	} else {
+		/* Normal (Non LSO) packet */
+		op_own = cpu_to_be32(MLX4_OPCODE_SEND) |
+			((ring->prod & ring->size) ?
+			 cpu_to_be32(MLX4_EN_BIT_DESC_OWN) : 0);
+		tx_info->nr_bytes = max_t(unsigned int, skb->len, ETH_ZLEN);
+		ring->packets++;
+	}
+	ring->bytes += tx_info->nr_bytes;
+
+	if (tx_info->inl)
+		build_inline_wqe(tx_desc, skb, shinfo, fragptr);
+
+	if (skb->encapsulation) {
+		union {
+			struct iphdr *v4;
+			struct ipv6hdr *v6;
+			unsigned char *hdr;
+		} ip;
+		u8 proto;
+
+		ip.hdr = skb_inner_network_header(skb);
+		proto = (ip.v4->version == 4) ? ip.v4->protocol :
+						ip.v6->nexthdr;
+
+		if (proto == IPPROTO_TCP || proto == IPPROTO_UDP)
+			op_own |= cpu_to_be32(MLX4_WQE_CTRL_IIP | MLX4_WQE_CTRL_ILP);
+		else
+			op_own |= cpu_to_be32(MLX4_WQE_CTRL_IIP);
+	}
+
+	WRITE_ONCE(ring->prod, ring->prod + nr_txbb);
+
+	/* If we used a bounce buffer then copy descriptor back into place */
+	if (unlikely(bounce))
+		tx_desc = mlx4_en_bounce_to_desc(priv, ring, index, desc_size);
+
+	skb_tx_timestamp(skb);
+
+	/* Check available TXBBs And 2K spare for prefetch */
+	stop_queue = mlx4_en_is_tx_ring_full(ring);
+	if (unlikely(stop_queue)) {
+		netif_tx_stop_queue(ring->tx_queue);
+		ring->queue_stopped++;
+	}
+
+	send_doorbell = __netdev_tx_sent_queue(ring->tx_queue,
+					       tx_info->nr_bytes,
+					       netdev_xmit_more());
+
+	real_size = (real_size / 16) & 0x3f;
+
+	bf_ok &= desc_size <= MAX_BF && send_doorbell;
+
+	if (bf_ok)
+		qpn_vlan.bf_qpn = ring->doorbell_qpn | cpu_to_be32(real_size);
+	else
+		qpn_vlan.fence_size = real_size;
+
+	mlx4_en_tx_write_desc(ring, tx_desc, qpn_vlan, desc_size, bf_index,
+			      op_own, bf_ok, send_doorbell);
+
+	if (unlikely(stop_queue)) {
+		/* If queue was emptied after the if (stop_queue) , and before
+		 * the netif_tx_stop_queue() - need to wake the queue,
+		 * or else it will remain stopped forever.
+		 * Need a memory barrier to make sure ring->cons was not
+		 * updated before queue was stopped.
+		 */
+		smp_rmb();
+
+		if (unlikely(!mlx4_en_is_tx_ring_full(ring))) {
+			netif_tx_wake_queue(ring->tx_queue);
+			ring->wake_queue++;
+		}
+	}
+	return NETDEV_TX_OK;
+
+tx_drop_count:
+	ring->tx_dropped++;
+tx_drop:
+	dev_kfree_skb_any(skb);
+	return NETDEV_TX_OK;
+}
+
+#define MLX4_EN_XDP_TX_NRTXBB  1
+#define MLX4_EN_XDP_TX_REAL_SZ (((CTRL_SIZE + MLX4_EN_XDP_TX_NRTXBB * DS_SIZE) \
+				 / 16) & 0x3f)
+
+void mlx4_en_init_tx_xdp_ring_descs(struct mlx4_en_priv *priv,
+				    struct mlx4_en_tx_ring *ring)
+{
+	int i;
+
+	for (i = 0; i < ring->size; i++) {
+		struct mlx4_en_tx_info *tx_info = &ring->tx_info[i];
+		struct mlx4_en_tx_desc *tx_desc = ring->buf +
+			(i << LOG_TXBB_SIZE);
+
+		tx_info->map0_byte_count = PAGE_SIZE;
+		tx_info->nr_txbb = MLX4_EN_XDP_TX_NRTXBB;
+		tx_info->data_offset = offsetof(struct mlx4_en_tx_desc, data);
+		tx_info->ts_requested = 0;
+		tx_info->nr_maps = 1;
+		tx_info->linear = 1;
+		tx_info->inl = 0;
+
+		tx_desc->data.lkey = ring->mr_key;
+		tx_desc->ctrl.qpn_vlan.fence_size = MLX4_EN_XDP_TX_REAL_SZ;
+		tx_desc->ctrl.srcrb_flags = priv->ctrl_flags;
+	}
+}
+
+netdev_tx_t mlx4_en_xmit_frame(struct mlx4_en_rx_ring *rx_ring,
+			       struct mlx4_en_rx_alloc *frame,
+			       struct mlx4_en_priv *priv, unsigned int length,
+			       int tx_ind, bool *doorbell_pending)
+{
+	struct mlx4_en_tx_desc *tx_desc;
+	struct mlx4_en_tx_info *tx_info;
+	struct mlx4_wqe_data_seg *data;
+	struct mlx4_en_tx_ring *ring;
+	dma_addr_t dma;
+	__be32 op_own;
+	int index;
+
+	if (unlikely(!priv->port_up))
+		goto tx_drop;
+
+	ring = priv->tx_ring[TX_XDP][tx_ind];
+
+	if (unlikely(mlx4_en_is_tx_ring_full(ring)))
+		goto tx_drop_count;
+
+	index = ring->prod & ring->size_mask;
+	tx_info = &ring->tx_info[index];
+
+	tx_desc = ring->buf + (index << LOG_TXBB_SIZE);
+	data = &tx_desc->data;
+
+	dma = frame->dma;
+
+	tx_info->page = frame->page;
+	frame->page = NULL;
+	tx_info->map0_dma = dma;
+	tx_info->nr_bytes = max_t(unsigned int, length, ETH_ZLEN);
+
+	dma_sync_single_range_for_device(priv->ddev, dma, frame->page_offset,
+					 length, DMA_TO_DEVICE);
+
+	data->addr = cpu_to_be64(dma + frame->page_offset);
+	dma_wmb();
+	data->byte_count = cpu_to_be32(length);
+
+	/* tx completion can avoid cache line miss for common cases */
+
+	op_own = cpu_to_be32(MLX4_OPCODE_SEND) |
+		((ring->prod & ring->size) ?
+		 cpu_to_be32(MLX4_EN_BIT_DESC_OWN) : 0);
+
+	rx_ring->xdp_tx++;
+
+	WRITE_ONCE(ring->prod, ring->prod + MLX4_EN_XDP_TX_NRTXBB);
+
+	/* Ensure new descriptor hits memory
+	 * before setting ownership of this descriptor to HW
+	 */
+	dma_wmb();
+	tx_desc->ctrl.owner_opcode = op_own;
+	ring->xmit_more++;
+
+	*doorbell_pending = true;
+
+	return NETDEV_TX_OK;
+
+tx_drop_count:
+	rx_ring->xdp_tx_full++;
+	*doorbell_pending = true;
+tx_drop:
+	return NETDEV_TX_BUSY;
+}