i40evf: transmit and receive functionality

This file contains the transmit, receive, and NAPI functionality.

Some of the functions in this module are extracted from the i40e driver
but functions that are not appropriate for virtual function devices have
been removed.
Signed-off-by: Mitch Williams <mitch.a.williams@intel.com>
Signed-off-by: Greg Rose <gregory.v.rose@intel.com>
Tested-by: Sibai Li <sibai.li@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/i40evf/i40e_txrx.c

+/*******************************************************************************
+ *
+ * Intel Ethernet Controller XL710 Family Linux Virtual Function Driver
+ * Copyright(c) 2013 Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * The full GNU General Public License is included in this distribution in
+ * the file called "COPYING".
+ *
+ * Contact Information:
+ * e1000-devel Mailing List <e1000-devel@lists.sourceforge.net>
+ * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
+ *
+ ******************************************************************************/
+
+#include "i40evf.h"
+
+static inline __le64 build_ctob(u32 td_cmd, u32 td_offset, unsigned int size,
+				u32 td_tag)
+{
+	return cpu_to_le64(I40E_TX_DESC_DTYPE_DATA |
+			   ((u64)td_cmd  << I40E_TXD_QW1_CMD_SHIFT) |
+			   ((u64)td_offset << I40E_TXD_QW1_OFFSET_SHIFT) |
+			   ((u64)size  << I40E_TXD_QW1_TX_BUF_SZ_SHIFT) |
+			   ((u64)td_tag  << I40E_TXD_QW1_L2TAG1_SHIFT));
+}
+
+#define I40E_TXD_CMD (I40E_TX_DESC_CMD_EOP | I40E_TX_DESC_CMD_RS)
+
+/**
+ * i40e_unmap_and_free_tx_resource - Release a Tx buffer
+ * @ring:      the ring that owns the buffer
+ * @tx_buffer: the buffer to free
+ **/
+static void i40e_unmap_and_free_tx_resource(struct i40e_ring *ring,
+					    struct i40e_tx_buffer *tx_buffer)
+{
+	if (tx_buffer->skb) {
+		dev_kfree_skb_any(tx_buffer->skb);
+		if (dma_unmap_len(tx_buffer, len))
+			dma_unmap_single(ring->dev,
+					 dma_unmap_addr(tx_buffer, dma),
+					 dma_unmap_len(tx_buffer, len),
+					 DMA_TO_DEVICE);
+	} else if (dma_unmap_len(tx_buffer, len)) {
+		dma_unmap_page(ring->dev,
+			       dma_unmap_addr(tx_buffer, dma),
+			       dma_unmap_len(tx_buffer, len),
+			       DMA_TO_DEVICE);
+	}
+	tx_buffer->next_to_watch = NULL;
+	tx_buffer->skb = NULL;
+	dma_unmap_len_set(tx_buffer, len, 0);
+	/* tx_buffer must be completely set up in the transmit path */
+}
+
+/**
+ * i40evf_clean_tx_ring - Free any empty Tx buffers
+ * @tx_ring: ring to be cleaned
+ **/
+void i40evf_clean_tx_ring(struct i40e_ring *tx_ring)
+{
+	unsigned long bi_size;
+	u16 i;
+
+	/* ring already cleared, nothing to do */
+	if (!tx_ring->tx_bi)
+		return;
+
+	/* Free all the Tx ring sk_buffs */
+	for (i = 0; i < tx_ring->count; i++)
+		i40e_unmap_and_free_tx_resource(tx_ring, &tx_ring->tx_bi[i]);
+
+	bi_size = sizeof(struct i40e_tx_buffer) * tx_ring->count;
+	memset(tx_ring->tx_bi, 0, bi_size);
+
+	/* Zero out the descriptor ring */
+	memset(tx_ring->desc, 0, tx_ring->size);
+
+	tx_ring->next_to_use = 0;
+	tx_ring->next_to_clean = 0;
+
+	if (!tx_ring->netdev)
+		return;
+
+	/* cleanup Tx queue statistics */
+	netdev_tx_reset_queue(netdev_get_tx_queue(tx_ring->netdev,
+						  tx_ring->queue_index));
+}
+
+/**
+ * i40evf_free_tx_resources - Free Tx resources per queue
+ * @tx_ring: Tx descriptor ring for a specific queue
+ *
+ * Free all transmit software resources
+ **/
+void i40evf_free_tx_resources(struct i40e_ring *tx_ring)
+{
+	i40evf_clean_tx_ring(tx_ring);
+	kfree(tx_ring->tx_bi);
+	tx_ring->tx_bi = NULL;
+
+	if (tx_ring->desc) {
+		dma_free_coherent(tx_ring->dev, tx_ring->size,
+				  tx_ring->desc, tx_ring->dma);
+		tx_ring->desc = NULL;
+	}
+}
+
+/**
+ * i40e_get_tx_pending - how many tx descriptors not processed
+ * @tx_ring: the ring of descriptors
+ *
+ * Since there is no access to the ring head register
+ * in XL710, we need to use our local copies
+ **/
+static u32 i40e_get_tx_pending(struct i40e_ring *ring)
+{
+	u32 ntu = ((ring->next_to_clean <= ring->next_to_use)
+			? ring->next_to_use
+			: ring->next_to_use + ring->count);
+	return ntu - ring->next_to_clean;
+}
+
+/**
+ * i40e_check_tx_hang - Is there a hang in the Tx queue
+ * @tx_ring: the ring of descriptors
+ **/
+static bool i40e_check_tx_hang(struct i40e_ring *tx_ring)
+{
+	u32 tx_pending = i40e_get_tx_pending(tx_ring);
+	bool ret = false;
+
+	clear_check_for_tx_hang(tx_ring);
+
+	/* Check for a hung queue, but be thorough. This verifies
+	 * that a transmit has been completed since the previous
+	 * check AND there is at least one packet pending. The
+	 * ARMED bit is set to indicate a potential hang. The
+	 * bit is cleared if a pause frame is received to remove
+	 * false hang detection due to PFC or 802.3x frames. By
+	 * requiring this to fail twice we avoid races with
+	 * PFC clearing the ARMED bit and conditions where we
+	 * run the check_tx_hang logic with a transmit completion
+	 * pending but without time to complete it yet.
+	 */
+	if ((tx_ring->tx_stats.tx_done_old == tx_ring->stats.packets) &&
+	    tx_pending) {
+		/* make sure it is true for two checks in a row */
+		ret = test_and_set_bit(__I40E_HANG_CHECK_ARMED,
+				       &tx_ring->state);
+	} else {
+		/* update completed stats and disarm the hang check */
+		tx_ring->tx_stats.tx_done_old = tx_ring->stats.packets;
+		clear_bit(__I40E_HANG_CHECK_ARMED, &tx_ring->state);
+	}
+
+	return ret;
+}
+
+/**
+ * i40e_clean_tx_irq - Reclaim resources after transmit completes
+ * @tx_ring:  tx ring to clean
+ * @budget:   how many cleans we're allowed
+ *
+ * Returns true if there's any budget left (e.g. the clean is finished)
+ **/
+static bool i40e_clean_tx_irq(struct i40e_ring *tx_ring, int budget)
+{
+	u16 i = tx_ring->next_to_clean;
+	struct i40e_tx_buffer *tx_buf;
+	struct i40e_tx_desc *tx_desc;
+	unsigned int total_packets = 0;
+	unsigned int total_bytes = 0;
+
+	tx_buf = &tx_ring->tx_bi[i];
+	tx_desc = I40E_TX_DESC(tx_ring, i);
+	i -= tx_ring->count;
+
+	do {
+		struct i40e_tx_desc *eop_desc = tx_buf->next_to_watch;
+
+		/* if next_to_watch is not set then there is no work pending */
+		if (!eop_desc)
+			break;
+
+		/* prevent any other reads prior to eop_desc */
+		read_barrier_depends();
+
+		/* if the descriptor isn't done, no work yet to do */
+		if (!(eop_desc->cmd_type_offset_bsz &
+		      cpu_to_le64(I40E_TX_DESC_DTYPE_DESC_DONE)))
+			break;
+
+		/* clear next_to_watch to prevent false hangs */
+		tx_buf->next_to_watch = NULL;
+
+		/* update the statistics for this packet */
+		total_bytes += tx_buf->bytecount;
+		total_packets += tx_buf->gso_segs;
+
+		/* free the skb */
+		dev_kfree_skb_any(tx_buf->skb);
+
+		/* unmap skb header data */
+		dma_unmap_single(tx_ring->dev,
+				 dma_unmap_addr(tx_buf, dma),
+				 dma_unmap_len(tx_buf, len),
+				 DMA_TO_DEVICE);
+
+		/* clear tx_buffer data */
+		tx_buf->skb = NULL;
+		dma_unmap_len_set(tx_buf, len, 0);
+
+		/* unmap remaining buffers */
+		while (tx_desc != eop_desc) {
+
+			tx_buf++;
+			tx_desc++;
+			i++;
+			if (unlikely(!i)) {
+				i -= tx_ring->count;
+				tx_buf = tx_ring->tx_bi;
+				tx_desc = I40E_TX_DESC(tx_ring, 0);
+			}
+
+			/* unmap any remaining paged data */
+			if (dma_unmap_len(tx_buf, len)) {
+				dma_unmap_page(tx_ring->dev,
+					       dma_unmap_addr(tx_buf, dma),
+					       dma_unmap_len(tx_buf, len),
+					       DMA_TO_DEVICE);
+				dma_unmap_len_set(tx_buf, len, 0);
+			}
+		}
+
+		/* move us one more past the eop_desc for start of next pkt */
+		tx_buf++;
+		tx_desc++;
+		i++;
+		if (unlikely(!i)) {
+			i -= tx_ring->count;
+			tx_buf = tx_ring->tx_bi;
+			tx_desc = I40E_TX_DESC(tx_ring, 0);
+		}
+
+		/* update budget accounting */
+		budget--;
+	} while (likely(budget));
+
+	i += tx_ring->count;
+	tx_ring->next_to_clean = i;
+	u64_stats_update_begin(&tx_ring->syncp);
+	tx_ring->stats.bytes += total_bytes;
+	tx_ring->stats.packets += total_packets;
+	u64_stats_update_end(&tx_ring->syncp);
+	tx_ring->q_vector->tx.total_bytes += total_bytes;
+	tx_ring->q_vector->tx.total_packets += total_packets;
+
+	if (check_for_tx_hang(tx_ring) && i40e_check_tx_hang(tx_ring)) {
+		/* schedule immediate reset if we believe we hung */
+		dev_info(tx_ring->dev, "Detected Tx Unit Hang\n"
+			 "  VSI                  <%d>\n"
+			 "  Tx Queue             <%d>\n"
+			 "  next_to_use          <%x>\n"
+			 "  next_to_clean        <%x>\n",
+			 tx_ring->vsi->seid,
+			 tx_ring->queue_index,
+			 tx_ring->next_to_use, i);
+		dev_info(tx_ring->dev, "tx_bi[next_to_clean]\n"
+			 "  time_stamp           <%lx>\n"
+			 "  jiffies              <%lx>\n",
+			 tx_ring->tx_bi[i].time_stamp, jiffies);
+
+		netif_stop_subqueue(tx_ring->netdev, tx_ring->queue_index);
+
+		dev_info(tx_ring->dev,
+			 "tx hang detected on queue %d, resetting adapter\n",
+			 tx_ring->queue_index);
+
+		tx_ring->netdev->netdev_ops->ndo_tx_timeout(tx_ring->netdev);
+
+		/* the adapter is about to reset, no point in enabling stuff */
+		return true;
+	}
+
+	netdev_tx_completed_queue(netdev_get_tx_queue(tx_ring->netdev,
+						      tx_ring->queue_index),
+				  total_packets, total_bytes);
+
+#define TX_WAKE_THRESHOLD (DESC_NEEDED * 2)
+	if (unlikely(total_packets && netif_carrier_ok(tx_ring->netdev) &&
+		     (I40E_DESC_UNUSED(tx_ring) >= TX_WAKE_THRESHOLD))) {
+		/* Make sure that anybody stopping the queue after this
+		 * sees the new next_to_clean.
+		 */
+		smp_mb();
+		if (__netif_subqueue_stopped(tx_ring->netdev,
+					     tx_ring->queue_index) &&
+		   !test_bit(__I40E_DOWN, &tx_ring->vsi->state)) {
+			netif_wake_subqueue(tx_ring->netdev,
+					    tx_ring->queue_index);
+			++tx_ring->tx_stats.restart_queue;
+		}
+	}
+
+	return budget > 0;
+}
+
+/**
+ * i40e_set_new_dynamic_itr - Find new ITR level
+ * @rc: structure containing ring performance data
+ *
+ * Stores a new ITR value based on packets and byte counts during
+ * the last interrupt.  The advantage of per interrupt computation
+ * is faster updates and more accurate ITR for the current traffic
+ * pattern.  Constants in this function were computed based on
+ * theoretical maximum wire speed and thresholds were set based on
+ * testing data as well as attempting to minimize response time
+ * while increasing bulk throughput.
+ **/
+static void i40e_set_new_dynamic_itr(struct i40e_ring_container *rc)
+{
+	enum i40e_latency_range new_latency_range = rc->latency_range;
+	u32 new_itr = rc->itr;
+	int bytes_per_int;
+
+	if (rc->total_packets == 0 || !rc->itr)
+		return;
+
+	/* simple throttlerate management
+	 *   0-10MB/s   lowest (100000 ints/s)
+	 *  10-20MB/s   low    (20000 ints/s)
+	 *  20-1249MB/s bulk   (8000 ints/s)
+	 */
+	bytes_per_int = rc->total_bytes / rc->itr;
+	switch (rc->itr) {
+	case I40E_LOWEST_LATENCY:
+		if (bytes_per_int > 10)
+			new_latency_range = I40E_LOW_LATENCY;
+		break;
+	case I40E_LOW_LATENCY:
+		if (bytes_per_int > 20)
+			new_latency_range = I40E_BULK_LATENCY;
+		else if (bytes_per_int <= 10)
+			new_latency_range = I40E_LOWEST_LATENCY;
+		break;
+	case I40E_BULK_LATENCY:
+		if (bytes_per_int <= 20)
+			rc->latency_range = I40E_LOW_LATENCY;
+		break;
+	}
+
+	switch (new_latency_range) {
+	case I40E_LOWEST_LATENCY:
+		new_itr = I40E_ITR_100K;
+		break;
+	case I40E_LOW_LATENCY:
+		new_itr = I40E_ITR_20K;
+		break;
+	case I40E_BULK_LATENCY:
+		new_itr = I40E_ITR_8K;
+		break;
+	default:
+		break;
+	}
+
+	if (new_itr != rc->itr) {
+		/* do an exponential smoothing */
+		new_itr = (10 * new_itr * rc->itr) /
+			  ((9 * new_itr) + rc->itr);
+		rc->itr = new_itr & I40E_MAX_ITR;
+	}
+
+	rc->total_bytes = 0;
+	rc->total_packets = 0;
+}
+
+/**
+ * i40e_update_dynamic_itr - Adjust ITR based on bytes per int
+ * @q_vector: the vector to adjust
+ **/
+static void i40e_update_dynamic_itr(struct i40e_q_vector *q_vector)
+{
+	u16 vector = q_vector->vsi->base_vector + q_vector->v_idx;
+	struct i40e_hw *hw = &q_vector->vsi->back->hw;
+	u32 reg_addr;
+	u16 old_itr;
+
+	reg_addr = I40E_VFINT_ITRN1(I40E_RX_ITR, vector - 1);
+	old_itr = q_vector->rx.itr;
+	i40e_set_new_dynamic_itr(&q_vector->rx);
+	if (old_itr != q_vector->rx.itr)
+		wr32(hw, reg_addr, q_vector->rx.itr);
+
+	reg_addr = I40E_VFINT_ITRN1(I40E_TX_ITR, vector - 1);
+	old_itr = q_vector->tx.itr;
+	i40e_set_new_dynamic_itr(&q_vector->tx);
+	if (old_itr != q_vector->tx.itr)
+		wr32(hw, reg_addr, q_vector->tx.itr);
+}
+
+/**
+ * i40evf_setup_tx_descriptors - Allocate the Tx descriptors
+ * @tx_ring: the tx ring to set up
+ *
+ * Return 0 on success, negative on error
+ **/
+int i40evf_setup_tx_descriptors(struct i40e_ring *tx_ring)
+{
+	struct device *dev = tx_ring->dev;
+	int bi_size;
+
+	if (!dev)
+		return -ENOMEM;
+
+	bi_size = sizeof(struct i40e_tx_buffer) * tx_ring->count;
+	tx_ring->tx_bi = kzalloc(bi_size, GFP_KERNEL);
+	if (!tx_ring->tx_bi)
+		goto err;
+
+	/* round up to nearest 4K */
+	tx_ring->size = tx_ring->count * sizeof(struct i40e_tx_desc);
+	tx_ring->size = ALIGN(tx_ring->size, 4096);
+	tx_ring->desc = dma_alloc_coherent(dev, tx_ring->size,
+					   &tx_ring->dma, GFP_KERNEL);
+	if (!tx_ring->desc) {
+		dev_info(dev, "Unable to allocate memory for the Tx descriptor ring, size=%d\n",
+			 tx_ring->size);
+		goto err;
+	}
+
+	tx_ring->next_to_use = 0;
+	tx_ring->next_to_clean = 0;
+	return 0;
+
+err:
+	kfree(tx_ring->tx_bi);
+	tx_ring->tx_bi = NULL;
+	return -ENOMEM;
+}
+
+/**
+ * i40evf_clean_rx_ring - Free Rx buffers
+ * @rx_ring: ring to be cleaned
+ **/
+void i40evf_clean_rx_ring(struct i40e_ring *rx_ring)
+{
+	struct device *dev = rx_ring->dev;
+	struct i40e_rx_buffer *rx_bi;
+	unsigned long bi_size;
+	u16 i;
+
+	/* ring already cleared, nothing to do */
+	if (!rx_ring->rx_bi)
+		return;
+
+	/* Free all the Rx ring sk_buffs */
+	for (i = 0; i < rx_ring->count; i++) {
+		rx_bi = &rx_ring->rx_bi[i];
+		if (rx_bi->dma) {
+			dma_unmap_single(dev,
+					 rx_bi->dma,
+					 rx_ring->rx_buf_len,
+					 DMA_FROM_DEVICE);
+			rx_bi->dma = 0;
+		}
+		if (rx_bi->skb) {
+			dev_kfree_skb(rx_bi->skb);
+			rx_bi->skb = NULL;
+		}
+		if (rx_bi->page) {
+			if (rx_bi->page_dma) {
+				dma_unmap_page(dev,
+					       rx_bi->page_dma,
+					       PAGE_SIZE / 2,
+					       DMA_FROM_DEVICE);
+				rx_bi->page_dma = 0;
+			}
+			__free_page(rx_bi->page);
+			rx_bi->page = NULL;
+			rx_bi->page_offset = 0;
+		}
+	}
+
+	bi_size = sizeof(struct i40e_rx_buffer) * rx_ring->count;
+	memset(rx_ring->rx_bi, 0, bi_size);
+
+	/* Zero out the descriptor ring */
+	memset(rx_ring->desc, 0, rx_ring->size);
+
+	rx_ring->next_to_clean = 0;
+	rx_ring->next_to_use = 0;
+}
+
+/**
+ * i40evf_free_rx_resources - Free Rx resources
+ * @rx_ring: ring to clean the resources from
+ *
+ * Free all receive software resources
+ **/
+void i40evf_free_rx_resources(struct i40e_ring *rx_ring)
+{
+	i40evf_clean_rx_ring(rx_ring);
+	kfree(rx_ring->rx_bi);
+	rx_ring->rx_bi = NULL;
+
+	if (rx_ring->desc) {
+		dma_free_coherent(rx_ring->dev, rx_ring->size,
+				  rx_ring->desc, rx_ring->dma);
+		rx_ring->desc = NULL;
+	}
+}
+
+/**
+ * i40evf_setup_rx_descriptors - Allocate Rx descriptors
+ * @rx_ring: Rx descriptor ring (for a specific queue) to setup
+ *
+ * Returns 0 on success, negative on failure
+ **/
+int i40evf_setup_rx_descriptors(struct i40e_ring *rx_ring)
+{
+	struct device *dev = rx_ring->dev;
+	int bi_size;
+
+	bi_size = sizeof(struct i40e_rx_buffer) * rx_ring->count;
+	rx_ring->rx_bi = kzalloc(bi_size, GFP_KERNEL);
+	if (!rx_ring->rx_bi)
+		goto err;
+
+	/* Round up to nearest 4K */
+	rx_ring->size = ring_is_16byte_desc_enabled(rx_ring)
+		? rx_ring->count * sizeof(union i40e_16byte_rx_desc)
+		: rx_ring->count * sizeof(union i40e_32byte_rx_desc);
+	rx_ring->size = ALIGN(rx_ring->size, 4096);
+	rx_ring->desc = dma_alloc_coherent(dev, rx_ring->size,
+					   &rx_ring->dma, GFP_KERNEL);
+
+	if (!rx_ring->desc) {
+		dev_info(dev, "Unable to allocate memory for the Rx descriptor ring, size=%d\n",
+			 rx_ring->size);
+		goto err;
+	}
+
+	rx_ring->next_to_clean = 0;
+	rx_ring->next_to_use = 0;
+
+	return 0;
+err:
+	kfree(rx_ring->rx_bi);
+	rx_ring->rx_bi = NULL;
+	return -ENOMEM;
+}
+
+/**
+ * i40e_release_rx_desc - Store the new tail and head values
+ * @rx_ring: ring to bump
+ * @val: new head index
+ **/
+static inline void i40e_release_rx_desc(struct i40e_ring *rx_ring, u32 val)
+{
+	rx_ring->next_to_use = val;
+	/* Force memory writes to complete before letting h/w
+	 * know there are new descriptors to fetch.  (Only
+	 * applicable for weak-ordered memory model archs,
+	 * such as IA-64).
+	 */
+	wmb();
+	writel(val, rx_ring->tail);
+}
+
+/**
+ * i40evf_alloc_rx_buffers - Replace used receive buffers; packet split
+ * @rx_ring: ring to place buffers on
+ * @cleaned_count: number of buffers to replace
+ **/
+void i40evf_alloc_rx_buffers(struct i40e_ring *rx_ring, u16 cleaned_count)
+{
+	u16 i = rx_ring->next_to_use;
+	union i40e_rx_desc *rx_desc;
+	struct i40e_rx_buffer *bi;
+	struct sk_buff *skb;
+
+	/* do nothing if no valid netdev defined */
+	if (!rx_ring->netdev || !cleaned_count)
+		return;
+
+	while (cleaned_count--) {
+		rx_desc = I40E_RX_DESC(rx_ring, i);
+		bi = &rx_ring->rx_bi[i];
+		skb = bi->skb;
+
+		if (!skb) {
+			skb = netdev_alloc_skb_ip_align(rx_ring->netdev,
+							rx_ring->rx_buf_len);
+			if (!skb) {
+				rx_ring->rx_stats.alloc_buff_failed++;
+				goto no_buffers;
+			}
+			/* initialize queue mapping */
+			skb_record_rx_queue(skb, rx_ring->queue_index);
+			bi->skb = skb;
+		}
+
+		if (!bi->dma) {
+			bi->dma = dma_map_single(rx_ring->dev,
+						 skb->data,
+						 rx_ring->rx_buf_len,
+						 DMA_FROM_DEVICE);
+			if (dma_mapping_error(rx_ring->dev, bi->dma)) {
+				rx_ring->rx_stats.alloc_buff_failed++;
+				bi->dma = 0;
+				goto no_buffers;
+			}
+		}
+
+		if (ring_is_ps_enabled(rx_ring)) {
+			if (!bi->page) {
+				bi->page = alloc_page(GFP_ATOMIC);
+				if (!bi->page) {
+					rx_ring->rx_stats.alloc_page_failed++;
+					goto no_buffers;
+				}
+			}
+
+			if (!bi->page_dma) {
+				/* use a half page if we're re-using */
+				bi->page_offset ^= PAGE_SIZE / 2;
+				bi->page_dma = dma_map_page(rx_ring->dev,
+							    bi->page,
+							    bi->page_offset,
+							    PAGE_SIZE / 2,
+							    DMA_FROM_DEVICE);
+				if (dma_mapping_error(rx_ring->dev,
+						      bi->page_dma)) {
+					rx_ring->rx_stats.alloc_page_failed++;
+					bi->page_dma = 0;
+					goto no_buffers;
+				}
+			}
+
+			/* Refresh the desc even if buffer_addrs didn't change
+			 * because each write-back erases this info.
+			 */
+			rx_desc->read.pkt_addr = cpu_to_le64(bi->page_dma);
+			rx_desc->read.hdr_addr = cpu_to_le64(bi->dma);
+		} else {
+			rx_desc->read.pkt_addr = cpu_to_le64(bi->dma);
+			rx_desc->read.hdr_addr = 0;
+		}
+		i++;
+		if (i == rx_ring->count)
+			i = 0;
+	}
+
+no_buffers:
+	if (rx_ring->next_to_use != i)
+		i40e_release_rx_desc(rx_ring, i);
+}
+
+/**
+ * i40e_receive_skb - Send a completed packet up the stack
+ * @rx_ring:  rx ring in play
+ * @skb: packet to send up
+ * @vlan_tag: vlan tag for packet
+ **/
+static void i40e_receive_skb(struct i40e_ring *rx_ring,
+			     struct sk_buff *skb, u16 vlan_tag)
+{
+	struct i40e_q_vector *q_vector = rx_ring->q_vector;
+	struct i40e_vsi *vsi = rx_ring->vsi;
+	u64 flags = vsi->back->flags;
+
+	if (vlan_tag & VLAN_VID_MASK)
+		__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), vlan_tag);
+
+	if (flags & I40E_FLAG_IN_NETPOLL)
+		netif_rx(skb);
+	else
+		napi_gro_receive(&q_vector->napi, skb);
+}
+
+/**
+ * i40e_rx_checksum - Indicate in skb if hw indicated a good cksum
+ * @vsi: the VSI we care about
+ * @skb: skb currently being received and modified
+ * @rx_status: status value of last descriptor in packet
+ * @rx_error: error value of last descriptor in packet
+ * @rx_ptype: ptype value of last descriptor in packet
+ **/
+static inline void i40e_rx_checksum(struct i40e_vsi *vsi,
+				    struct sk_buff *skb,
+				    u32 rx_status,
+				    u32 rx_error,
+				    u16 rx_ptype)
+{
+	bool ipv4_tunnel, ipv6_tunnel;
+	__wsum rx_udp_csum;
+	__sum16 csum;
+	struct iphdr *iph;
+
+	ipv4_tunnel = (rx_ptype > I40E_RX_PTYPE_GRENAT4_MAC_PAY3) &&
+		      (rx_ptype < I40E_RX_PTYPE_GRENAT4_MACVLAN_IPV6_ICMP_PAY4);
+	ipv6_tunnel = (rx_ptype > I40E_RX_PTYPE_GRENAT6_MAC_PAY3) &&
+		      (rx_ptype < I40E_RX_PTYPE_GRENAT6_MACVLAN_IPV6_ICMP_PAY4);
+
+	skb->encapsulation = ipv4_tunnel || ipv6_tunnel;
+	skb->ip_summed = CHECKSUM_NONE;
+
+	/* Rx csum enabled and ip headers found? */
+	if (!(vsi->netdev->features & NETIF_F_RXCSUM &&
+	      rx_status & (1 << I40E_RX_DESC_STATUS_L3L4P_SHIFT)))
+		return;
+
+	/* likely incorrect csum if alternate IP extention headers found */
+	if (rx_status & (1 << I40E_RX_DESC_STATUS_IPV6EXADD_SHIFT))
+		return;
+
+	/* IP or L4 or outmost IP checksum error */
+	if (rx_error & ((1 << I40E_RX_DESC_ERROR_IPE_SHIFT) |
+			(1 << I40E_RX_DESC_ERROR_L4E_SHIFT) |
+			(1 << I40E_RX_DESC_ERROR_EIPE_SHIFT))) {
+		vsi->back->hw_csum_rx_error++;
+		return;
+	}
+
+	if (ipv4_tunnel &&
+	    !(rx_status & (1 << I40E_RX_DESC_STATUS_UDP_0_SHIFT))) {
+		/* If VXLAN traffic has an outer UDPv4 checksum we need to check
+		 * it in the driver, hardware does not do it for us.
+		 * Since L3L4P bit was set we assume a valid IHL value (>=5)
+		 * so the total length of IPv4 header is IHL*4 bytes
+		 */
+		skb->transport_header = skb->mac_header +
+					sizeof(struct ethhdr) +
+					(ip_hdr(skb)->ihl * 4);
+
+		/* Add 4 bytes for VLAN tagged packets */
+		skb->transport_header += (skb->protocol == htons(ETH_P_8021Q) ||
+					  skb->protocol == htons(ETH_P_8021AD))
+					  ? VLAN_HLEN : 0;
+
+		rx_udp_csum = udp_csum(skb);
+		iph = ip_hdr(skb);
+		csum = csum_tcpudp_magic(
+				iph->saddr, iph->daddr,
+				(skb->len - skb_transport_offset(skb)),
+				IPPROTO_UDP, rx_udp_csum);
+
+		if (udp_hdr(skb)->check != csum) {
+			vsi->back->hw_csum_rx_error++;
+			return;
+		}
+	}
+
+	skb->ip_summed = CHECKSUM_UNNECESSARY;
+}
+
+/**
+ * i40e_rx_hash - returns the hash value from the Rx descriptor
+ * @ring: descriptor ring
+ * @rx_desc: specific descriptor
+ **/
+static inline u32 i40e_rx_hash(struct i40e_ring *ring,
+			       union i40e_rx_desc *rx_desc)
+{
+	const __le64 rss_mask =
+		cpu_to_le64((u64)I40E_RX_DESC_FLTSTAT_RSS_HASH <<
+			    I40E_RX_DESC_STATUS_FLTSTAT_SHIFT);
+
+	if ((ring->netdev->features & NETIF_F_RXHASH) &&
+	    (rx_desc->wb.qword1.status_error_len & rss_mask) == rss_mask)
+		return le32_to_cpu(rx_desc->wb.qword0.hi_dword.rss);
+	else
+		return 0;
+}
+
+/**
+ * i40e_clean_rx_irq - Reclaim resources after receive completes
+ * @rx_ring:  rx ring to clean
+ * @budget:   how many cleans we're allowed
+ *
+ * Returns true if there's any budget left (e.g. the clean is finished)
+ **/
+static int i40e_clean_rx_irq(struct i40e_ring *rx_ring, int budget)
+{
+	unsigned int total_rx_bytes = 0, total_rx_packets = 0;
+	u16 rx_packet_len, rx_header_len, rx_sph, rx_hbo;
+	u16 cleaned_count = I40E_DESC_UNUSED(rx_ring);
+	const int current_node = numa_node_id();
+	struct i40e_vsi *vsi = rx_ring->vsi;
+	u16 i = rx_ring->next_to_clean;
+	union i40e_rx_desc *rx_desc;
+	u32 rx_error, rx_status;
+	u64 qword;
+	u16 rx_ptype;
+
+	rx_desc = I40E_RX_DESC(rx_ring, i);
+	qword = le64_to_cpu(rx_desc->wb.qword1.status_error_len);
+	rx_status = (qword & I40E_RXD_QW1_STATUS_MASK)
+				>> I40E_RXD_QW1_STATUS_SHIFT;
+
+	while (rx_status & (1 << I40E_RX_DESC_STATUS_DD_SHIFT)) {
+		union i40e_rx_desc *next_rxd;
+		struct i40e_rx_buffer *rx_bi;
+		struct sk_buff *skb;
+		u16 vlan_tag;
+		rx_bi = &rx_ring->rx_bi[i];
+		skb = rx_bi->skb;
+		prefetch(skb->data);
+
+		rx_packet_len = (qword & I40E_RXD_QW1_LENGTH_PBUF_MASK) >>
+				I40E_RXD_QW1_LENGTH_PBUF_SHIFT;
+		rx_header_len = (qword & I40E_RXD_QW1_LENGTH_HBUF_MASK) >>
+				I40E_RXD_QW1_LENGTH_HBUF_SHIFT;
+		rx_sph = (qword & I40E_RXD_QW1_LENGTH_SPH_MASK) >>
+			 I40E_RXD_QW1_LENGTH_SPH_SHIFT;
+
+		rx_error = (qword & I40E_RXD_QW1_ERROR_MASK) >>
+			   I40E_RXD_QW1_ERROR_SHIFT;
+		rx_hbo = rx_error & (1 << I40E_RX_DESC_ERROR_HBO_SHIFT);
+		rx_error &= ~(1 << I40E_RX_DESC_ERROR_HBO_SHIFT);
+
+		rx_ptype = (qword & I40E_RXD_QW1_PTYPE_MASK) >>
+			   I40E_RXD_QW1_PTYPE_SHIFT;
+		rx_bi->skb = NULL;
+
+		/* This memory barrier is needed to keep us from reading
+		 * any other fields out of the rx_desc until we know the
+		 * STATUS_DD bit is set
+		 */
+		rmb();
+
+		/* Get the header and possibly the whole packet
+		 * If this is an skb from previous receive dma will be 0
+		 */
+		if (rx_bi->dma) {
+			u16 len;
+
+			if (rx_hbo)
+				len = I40E_RX_HDR_SIZE;
+			else if (rx_sph)
+				len = rx_header_len;
+			else if (rx_packet_len)
+				len = rx_packet_len;   /* 1buf/no split found */
+			else
+				len = rx_header_len;   /* split always mode */
+
+			skb_put(skb, len);
+			dma_unmap_single(rx_ring->dev,
+					 rx_bi->dma,
+					 rx_ring->rx_buf_len,
+					 DMA_FROM_DEVICE);
+			rx_bi->dma = 0;
+		}
+
+		/* Get the rest of the data if this was a header split */
+		if (ring_is_ps_enabled(rx_ring) && rx_packet_len) {
+
+			skb_fill_page_desc(skb, skb_shinfo(skb)->nr_frags,
+					   rx_bi->page,
+					   rx_bi->page_offset,
+					   rx_packet_len);
+
+			skb->len += rx_packet_len;
+			skb->data_len += rx_packet_len;
+			skb->truesize += rx_packet_len;
+
+			if ((page_count(rx_bi->page) == 1) &&
+			    (page_to_nid(rx_bi->page) == current_node))
+				get_page(rx_bi->page);
+			else
+				rx_bi->page = NULL;
+
+			dma_unmap_page(rx_ring->dev,
+				       rx_bi->page_dma,
+				       PAGE_SIZE / 2,
+				       DMA_FROM_DEVICE);
+			rx_bi->page_dma = 0;
+		}
+		I40E_RX_NEXT_DESC_PREFETCH(rx_ring, i, next_rxd);
+
+		if (unlikely(
+		    !(rx_status & (1 << I40E_RX_DESC_STATUS_EOF_SHIFT)))) {
+			struct i40e_rx_buffer *next_buffer;
+
+			next_buffer = &rx_ring->rx_bi[i];
+
+			if (ring_is_ps_enabled(rx_ring)) {
+				rx_bi->skb = next_buffer->skb;
+				rx_bi->dma = next_buffer->dma;
+				next_buffer->skb = skb;
+				next_buffer->dma = 0;
+			}
+			rx_ring->rx_stats.non_eop_descs++;
+			goto next_desc;
+		}
+
+		/* ERR_MASK will only have valid bits if EOP set */
+		if (unlikely(rx_error & (1 << I40E_RX_DESC_ERROR_RXE_SHIFT))) {
+			dev_kfree_skb_any(skb);
+			goto next_desc;
+		}
+
+		skb->rxhash = i40e_rx_hash(rx_ring, rx_desc);
+		/* probably a little skewed due to removing CRC */
+		total_rx_bytes += skb->len;
+		total_rx_packets++;
+
+		skb->protocol = eth_type_trans(skb, rx_ring->netdev);
+
+		i40e_rx_checksum(vsi, skb, rx_status, rx_error, rx_ptype);
+
+		vlan_tag = rx_status & (1 << I40E_RX_DESC_STATUS_L2TAG1P_SHIFT)
+			 ? le16_to_cpu(rx_desc->wb.qword0.lo_dword.l2tag1)
+			 : 0;
+		i40e_receive_skb(rx_ring, skb, vlan_tag);
+
+		rx_ring->netdev->last_rx = jiffies;
+		budget--;
+next_desc:
+		rx_desc->wb.qword1.status_error_len = 0;
+		if (!budget)
+			break;
+
+		cleaned_count++;
+		/* return some buffers to hardware, one at a time is too slow */
+		if (cleaned_count >= I40E_RX_BUFFER_WRITE) {
+			i40evf_alloc_rx_buffers(rx_ring, cleaned_count);
+			cleaned_count = 0;
+		}
+
+		/* use prefetched values */
+		rx_desc = next_rxd;
+		qword = le64_to_cpu(rx_desc->wb.qword1.status_error_len);
+		rx_status = (qword & I40E_RXD_QW1_STATUS_MASK) >>
+			    I40E_RXD_QW1_STATUS_SHIFT;
+	}
+
+	rx_ring->next_to_clean = i;
+	u64_stats_update_begin(&rx_ring->syncp);
+	rx_ring->stats.packets += total_rx_packets;
+	rx_ring->stats.bytes += total_rx_bytes;
+	u64_stats_update_end(&rx_ring->syncp);
+	rx_ring->q_vector->rx.total_packets += total_rx_packets;
+	rx_ring->q_vector->rx.total_bytes += total_rx_bytes;
+
+	if (cleaned_count)
+		i40evf_alloc_rx_buffers(rx_ring, cleaned_count);
+
+	return budget > 0;
+}
+
+/**
+ * i40evf_napi_poll - NAPI polling Rx/Tx cleanup routine
+ * @napi: napi struct with our devices info in it
+ * @budget: amount of work driver is allowed to do this pass, in packets
+ *
+ * This function will clean all queues associated with a q_vector.
+ *
+ * Returns the amount of work done
+ **/
+int i40evf_napi_poll(struct napi_struct *napi, int budget)
+{
+	struct i40e_q_vector *q_vector =
+			       container_of(napi, struct i40e_q_vector, napi);
+	struct i40e_vsi *vsi = q_vector->vsi;
+	struct i40e_ring *ring;
+	bool clean_complete = true;
+	int budget_per_ring;
+
+	if (test_bit(__I40E_DOWN, &vsi->state)) {
+		napi_complete(napi);
+		return 0;
+	}
+
+	/* Since the actual Tx work is minimal, we can give the Tx a larger
+	 * budget and be more aggressive about cleaning up the Tx descriptors.
+	 */
+	i40e_for_each_ring(ring, q_vector->tx)
+		clean_complete &= i40e_clean_tx_irq(ring, vsi->work_limit);
+
+	/* We attempt to distribute budget to each Rx queue fairly, but don't
+	 * allow the budget to go below 1 because that would exit polling early.
+	 */
+	budget_per_ring = max(budget/q_vector->num_ringpairs, 1);
+
+	i40e_for_each_ring(ring, q_vector->rx)
+		clean_complete &= i40e_clean_rx_irq(ring, budget_per_ring);
+
+	/* If work not completed, return budget and polling will return */
+	if (!clean_complete)
+		return budget;
+
+	/* Work is done so exit the polling mode and re-enable the interrupt */
+	napi_complete(napi);
+	if (ITR_IS_DYNAMIC(vsi->rx_itr_setting) ||
+	    ITR_IS_DYNAMIC(vsi->tx_itr_setting))
+		i40e_update_dynamic_itr(q_vector);
+
+	if (!test_bit(__I40E_DOWN, &vsi->state))
+		i40evf_irq_enable_queues(vsi->back, 1 << q_vector->v_idx);
+
+	return 0;
+}
+
+/**
+ * i40e_tx_prepare_vlan_flags - prepare generic TX VLAN tagging flags for HW
+ * @skb:     send buffer
+ * @tx_ring: ring to send buffer on
+ * @flags:   the tx flags to be set
+ *
+ * Checks the skb and set up correspondingly several generic transmit flags
+ * related to VLAN tagging for the HW, such as VLAN, DCB, etc.
+ *
+ * Returns error code indicate the frame should be dropped upon error and the
+ * otherwise  returns 0 to indicate the flags has been set properly.
+ **/
+static int i40e_tx_prepare_vlan_flags(struct sk_buff *skb,
+				      struct i40e_ring *tx_ring,
+				      u32 *flags)
+{
+	__be16 protocol = skb->protocol;
+	u32  tx_flags = 0;
+
+	/* if we have a HW VLAN tag being added, default to the HW one */
+	if (vlan_tx_tag_present(skb)) {
+		tx_flags |= vlan_tx_tag_get(skb) << I40E_TX_FLAGS_VLAN_SHIFT;
+		tx_flags |= I40E_TX_FLAGS_HW_VLAN;
+	/* else if it is a SW VLAN, check the next protocol and store the tag */
+	} else if (protocol == htons(ETH_P_8021Q)) {
+		struct vlan_hdr *vhdr, _vhdr;
+		vhdr = skb_header_pointer(skb, ETH_HLEN, sizeof(_vhdr), &_vhdr);
+		if (!vhdr)
+			return -EINVAL;
+
+		protocol = vhdr->h_vlan_encapsulated_proto;
+		tx_flags |= ntohs(vhdr->h_vlan_TCI) << I40E_TX_FLAGS_VLAN_SHIFT;
+		tx_flags |= I40E_TX_FLAGS_SW_VLAN;
+	}
+
+	*flags = tx_flags;
+	return 0;
+}
+
+/**
+ * i40e_tso - set up the tso context descriptor
+ * @tx_ring:  ptr to the ring to send
+ * @skb:      ptr to the skb we're sending
+ * @tx_flags: the collected send information
+ * @protocol: the send protocol
+ * @hdr_len:  ptr to the size of the packet header
+ * @cd_tunneling: ptr to context descriptor bits
+ *
+ * Returns 0 if no TSO can happen, 1 if tso is going, or error
+ **/
+static int i40e_tso(struct i40e_ring *tx_ring, struct sk_buff *skb,
+		    u32 tx_flags, __be16 protocol, u8 *hdr_len,
+		    u64 *cd_type_cmd_tso_mss, u32 *cd_tunneling)
+{
+	u32 cd_cmd, cd_tso_len, cd_mss;
+	struct tcphdr *tcph;
+	struct iphdr *iph;
+	u32 l4len;
+	int err;
+	struct ipv6hdr *ipv6h;
+
+	if (!skb_is_gso(skb))
+		return 0;
+
+	if (skb_header_cloned(skb)) {
+		err = pskb_expand_head(skb, 0, 0, GFP_ATOMIC);
+		if (err)
+			return err;
+	}
+
+	if (protocol == htons(ETH_P_IP)) {
+		iph = skb->encapsulation ? inner_ip_hdr(skb) : ip_hdr(skb);
+		tcph = skb->encapsulation ? inner_tcp_hdr(skb) : tcp_hdr(skb);
+		iph->tot_len = 0;
+		iph->check = 0;
+		tcph->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr,
+						 0, IPPROTO_TCP, 0);
+	} else if (skb_is_gso_v6(skb)) {
+
+		ipv6h = skb->encapsulation ? inner_ipv6_hdr(skb)
+					   : ipv6_hdr(skb);
+		tcph = skb->encapsulation ? inner_tcp_hdr(skb) : tcp_hdr(skb);
+		ipv6h->payload_len = 0;
+		tcph->check = ~csum_ipv6_magic(&ipv6h->saddr, &ipv6h->daddr,
+					       0, IPPROTO_TCP, 0);
+	}
+
+	l4len = skb->encapsulation ? inner_tcp_hdrlen(skb) : tcp_hdrlen(skb);
+	*hdr_len = (skb->encapsulation
+		    ? (skb_inner_transport_header(skb) - skb->data)
+		    : skb_transport_offset(skb)) + l4len;
+
+	/* find the field values */
+	cd_cmd = I40E_TX_CTX_DESC_TSO;
+	cd_tso_len = skb->len - *hdr_len;
+	cd_mss = skb_shinfo(skb)->gso_size;
+	*cd_type_cmd_tso_mss |= ((u64)cd_cmd << I40E_TXD_CTX_QW1_CMD_SHIFT) |
+				((u64)cd_tso_len <<
+				 I40E_TXD_CTX_QW1_TSO_LEN_SHIFT) |
+				((u64)cd_mss << I40E_TXD_CTX_QW1_MSS_SHIFT);
+	return 1;
+}
+
+/**
+ * i40e_tx_enable_csum - Enable Tx checksum offloads
+ * @skb: send buffer
+ * @tx_flags: Tx flags currently set
+ * @td_cmd: Tx descriptor command bits to set
+ * @td_offset: Tx descriptor header offsets to set
+ * @cd_tunneling: ptr to context desc bits
+ **/
+static void i40e_tx_enable_csum(struct sk_buff *skb, u32 tx_flags,
+				u32 *td_cmd, u32 *td_offset,
+				struct i40e_ring *tx_ring,
+				u32 *cd_tunneling)
+{
+	struct ipv6hdr *this_ipv6_hdr;
+	unsigned int this_tcp_hdrlen;
+	struct iphdr *this_ip_hdr;
+	u32 network_hdr_len;
+	u8 l4_hdr = 0;
+
+	if (skb->encapsulation) {
+		network_hdr_len = skb_inner_network_header_len(skb);
+		this_ip_hdr = inner_ip_hdr(skb);
+		this_ipv6_hdr = inner_ipv6_hdr(skb);
+		this_tcp_hdrlen = inner_tcp_hdrlen(skb);
+
+		if (tx_flags & I40E_TX_FLAGS_IPV4) {
+
+			if (tx_flags & I40E_TX_FLAGS_TSO) {
+				*cd_tunneling |= I40E_TX_CTX_EXT_IP_IPV4;
+				ip_hdr(skb)->check = 0;
+			} else {
+				*cd_tunneling |=
+					 I40E_TX_CTX_EXT_IP_IPV4_NO_CSUM;
+			}
+		} else if (tx_flags & I40E_TX_FLAGS_IPV6) {
+			if (tx_flags & I40E_TX_FLAGS_TSO) {
+				*cd_tunneling |= I40E_TX_CTX_EXT_IP_IPV6;
+				ip_hdr(skb)->check = 0;
+			} else {
+				*cd_tunneling |=
+					 I40E_TX_CTX_EXT_IP_IPV4_NO_CSUM;
+			}
+		}
+
+		/* Now set the ctx descriptor fields */
+		*cd_tunneling |= (skb_network_header_len(skb) >> 2) <<
+					I40E_TXD_CTX_QW0_EXT_IPLEN_SHIFT |
+				   I40E_TXD_CTX_UDP_TUNNELING            |
+				   ((skb_inner_network_offset(skb) -
+					skb_transport_offset(skb)) >> 1) <<
+				   I40E_TXD_CTX_QW0_NATLEN_SHIFT;
+
+	} else {
+		network_hdr_len = skb_network_header_len(skb);
+		this_ip_hdr = ip_hdr(skb);
+		this_ipv6_hdr = ipv6_hdr(skb);
+		this_tcp_hdrlen = tcp_hdrlen(skb);
+	}
+
+	/* Enable IP checksum offloads */
+	if (tx_flags & I40E_TX_FLAGS_IPV4) {
+		l4_hdr = this_ip_hdr->protocol;
+		/* the stack computes the IP header already, the only time we
+		 * need the hardware to recompute it is in the case of TSO.
+		 */
+		if (tx_flags & I40E_TX_FLAGS_TSO) {
+			*td_cmd |= I40E_TX_DESC_CMD_IIPT_IPV4_CSUM;
+			this_ip_hdr->check = 0;
+		} else {
+			*td_cmd |= I40E_TX_DESC_CMD_IIPT_IPV4;
+		}
+		/* Now set the td_offset for IP header length */
+		*td_offset = (network_hdr_len >> 2) <<
+			      I40E_TX_DESC_LENGTH_IPLEN_SHIFT;
+	} else if (tx_flags & I40E_TX_FLAGS_IPV6) {
+		l4_hdr = this_ipv6_hdr->nexthdr;
+		*td_cmd |= I40E_TX_DESC_CMD_IIPT_IPV6;
+		/* Now set the td_offset for IP header length */
+		*td_offset = (network_hdr_len >> 2) <<
+			      I40E_TX_DESC_LENGTH_IPLEN_SHIFT;
+	}
+	/* words in MACLEN + dwords in IPLEN + dwords in L4Len */
+	*td_offset |= (skb_network_offset(skb) >> 1) <<
+		       I40E_TX_DESC_LENGTH_MACLEN_SHIFT;
+
+	/* Enable L4 checksum offloads */
+	switch (l4_hdr) {
+	case IPPROTO_TCP:
+		/* enable checksum offloads */
+		*td_cmd |= I40E_TX_DESC_CMD_L4T_EOFT_TCP;
+		*td_offset |= (this_tcp_hdrlen >> 2) <<
+			       I40E_TX_DESC_LENGTH_L4_FC_LEN_SHIFT;
+		break;
+	case IPPROTO_SCTP:
+		/* enable SCTP checksum offload */
+		*td_cmd |= I40E_TX_DESC_CMD_L4T_EOFT_SCTP;
+		*td_offset |= (sizeof(struct sctphdr) >> 2) <<
+			       I40E_TX_DESC_LENGTH_L4_FC_LEN_SHIFT;
+		break;
+	case IPPROTO_UDP:
+		/* enable UDP checksum offload */
+		*td_cmd |= I40E_TX_DESC_CMD_L4T_EOFT_UDP;
+		*td_offset |= (sizeof(struct udphdr) >> 2) <<
+			       I40E_TX_DESC_LENGTH_L4_FC_LEN_SHIFT;
+		break;
+	default:
+		break;
+	}
+}
+
+/**
+ * i40e_create_tx_ctx Build the Tx context descriptor
+ * @tx_ring:  ring to create the descriptor on
+ * @cd_type_cmd_tso_mss: Quad Word 1
+ * @cd_tunneling: Quad Word 0 - bits 0-31
+ * @cd_l2tag2: Quad Word 0 - bits 32-63
+ **/
+static void i40e_create_tx_ctx(struct i40e_ring *tx_ring,
+			       const u64 cd_type_cmd_tso_mss,
+			       const u32 cd_tunneling, const u32 cd_l2tag2)
+{
+	struct i40e_tx_context_desc *context_desc;
+	int i = tx_ring->next_to_use;
+
+	if (!cd_type_cmd_tso_mss && !cd_tunneling && !cd_l2tag2)
+		return;
+
+	/* grab the next descriptor */
+	context_desc = I40E_TX_CTXTDESC(tx_ring, i);
+
+	i++;
+	tx_ring->next_to_use = (i < tx_ring->count) ? i : 0;
+
+	/* cpu_to_le32 and assign to struct fields */
+	context_desc->tunneling_params = cpu_to_le32(cd_tunneling);
+	context_desc->l2tag2 = cpu_to_le16(cd_l2tag2);
+	context_desc->type_cmd_tso_mss = cpu_to_le64(cd_type_cmd_tso_mss);
+}
+
+/**
+ * i40e_tx_map - Build the Tx descriptor
+ * @tx_ring:  ring to send buffer on
+ * @skb:      send buffer
+ * @first:    first buffer info buffer to use
+ * @tx_flags: collected send information
+ * @hdr_len:  size of the packet header
+ * @td_cmd:   the command field in the descriptor
+ * @td_offset: offset for checksum or crc
+ **/
+static void i40e_tx_map(struct i40e_ring *tx_ring, struct sk_buff *skb,
+			struct i40e_tx_buffer *first, u32 tx_flags,
+			const u8 hdr_len, u32 td_cmd, u32 td_offset)
+{
+	unsigned int data_len = skb->data_len;
+	unsigned int size = skb_headlen(skb);
+	struct skb_frag_struct *frag;
+	struct i40e_tx_buffer *tx_bi;
+	struct i40e_tx_desc *tx_desc;
+	u16 i = tx_ring->next_to_use;
+	u32 td_tag = 0;
+	dma_addr_t dma;
+	u16 gso_segs;
+
+	if (tx_flags & I40E_TX_FLAGS_HW_VLAN) {
+		td_cmd |= I40E_TX_DESC_CMD_IL2TAG1;
+		td_tag = (tx_flags & I40E_TX_FLAGS_VLAN_MASK) >>
+			 I40E_TX_FLAGS_VLAN_SHIFT;
+	}
+
+	if (tx_flags & (I40E_TX_FLAGS_TSO | I40E_TX_FLAGS_FSO))
+		gso_segs = skb_shinfo(skb)->gso_segs;
+	else
+		gso_segs = 1;
+
+	/* multiply data chunks by size of headers */
+	first->bytecount = skb->len - hdr_len + (gso_segs * hdr_len);
+	first->gso_segs = gso_segs;
+	first->skb = skb;
+	first->tx_flags = tx_flags;
+
+	dma = dma_map_single(tx_ring->dev, skb->data, size, DMA_TO_DEVICE);
+
+	tx_desc = I40E_TX_DESC(tx_ring, i);
+	tx_bi = first;
+
+	for (frag = &skb_shinfo(skb)->frags[0];; frag++) {
+		if (dma_mapping_error(tx_ring->dev, dma))
+			goto dma_error;
+
+		/* record length, and DMA address */
+		dma_unmap_len_set(tx_bi, len, size);
+		dma_unmap_addr_set(tx_bi, dma, dma);
+
+		tx_desc->buffer_addr = cpu_to_le64(dma);
+
+		while (unlikely(size > I40E_MAX_DATA_PER_TXD)) {
+			tx_desc->cmd_type_offset_bsz =
+				build_ctob(td_cmd, td_offset,
+					   I40E_MAX_DATA_PER_TXD, td_tag);
+
+			tx_desc++;
+			i++;
+			if (i == tx_ring->count) {
+				tx_desc = I40E_TX_DESC(tx_ring, 0);
+				i = 0;
+			}
+
+			dma += I40E_MAX_DATA_PER_TXD;
+			size -= I40E_MAX_DATA_PER_TXD;
+
+			tx_desc->buffer_addr = cpu_to_le64(dma);
+		}
+
+		if (likely(!data_len))
+			break;
+
+		tx_desc->cmd_type_offset_bsz = build_ctob(td_cmd, td_offset,
+							  size, td_tag);
+
+		tx_desc++;
+		i++;
+		if (i == tx_ring->count) {
+			tx_desc = I40E_TX_DESC(tx_ring, 0);
+			i = 0;
+		}
+
+		size = skb_frag_size(frag);
+		data_len -= size;
+
+		dma = skb_frag_dma_map(tx_ring->dev, frag, 0, size,
+				       DMA_TO_DEVICE);
+
+		tx_bi = &tx_ring->tx_bi[i];
+	}
+
+	tx_desc->cmd_type_offset_bsz =
+		build_ctob(td_cmd, td_offset, size, td_tag) |
+		cpu_to_le64((u64)I40E_TXD_CMD << I40E_TXD_QW1_CMD_SHIFT);
+
+	netdev_tx_sent_queue(netdev_get_tx_queue(tx_ring->netdev,
+						 tx_ring->queue_index),
+			     first->bytecount);
+
+	/* set the timestamp */
+	first->time_stamp = jiffies;
+
+	/* Force memory writes to complete before letting h/w
+	 * know there are new descriptors to fetch.  (Only
+	 * applicable for weak-ordered memory model archs,
+	 * such as IA-64).
+	 */
+	wmb();
+
+	/* set next_to_watch value indicating a packet is present */
+	first->next_to_watch = tx_desc;
+
+	i++;
+	if (i == tx_ring->count)
+		i = 0;
+
+	tx_ring->next_to_use = i;
+
+	/* notify HW of packet */
+	writel(i, tx_ring->tail);
+
+	return;
+
+dma_error:
+	dev_info(tx_ring->dev, "TX DMA map failed\n");
+
+	/* clear dma mappings for failed tx_bi map */
+	for (;;) {
+		tx_bi = &tx_ring->tx_bi[i];
+		i40e_unmap_and_free_tx_resource(tx_ring, tx_bi);
+		if (tx_bi == first)
+			break;
+		if (i == 0)
+			i = tx_ring->count;
+		i--;
+	}
+
+	tx_ring->next_to_use = i;
+}
+
+/**
+ * __i40e_maybe_stop_tx - 2nd level check for tx stop conditions
+ * @tx_ring: the ring to be checked
+ * @size:    the size buffer we want to assure is available
+ *
+ * Returns -EBUSY if a stop is needed, else 0
+ **/
+static inline int __i40e_maybe_stop_tx(struct i40e_ring *tx_ring, int size)
+{
+	netif_stop_subqueue(tx_ring->netdev, tx_ring->queue_index);
+	/* Memory barrier before checking head and tail */
+	smp_mb();
+
+	/* Check again in a case another CPU has just made room available. */
+	if (likely(I40E_DESC_UNUSED(tx_ring) < size))
+		return -EBUSY;
+
+	/* A reprieve! - use start_queue because it doesn't call schedule */
+	netif_start_subqueue(tx_ring->netdev, tx_ring->queue_index);
+	++tx_ring->tx_stats.restart_queue;
+	return 0;
+}
+
+/**
+ * i40e_maybe_stop_tx - 1st level check for tx stop conditions
+ * @tx_ring: the ring to be checked
+ * @size:    the size buffer we want to assure is available
+ *
+ * Returns 0 if stop is not needed
+ **/
+static int i40e_maybe_stop_tx(struct i40e_ring *tx_ring, int size)
+{
+	if (likely(I40E_DESC_UNUSED(tx_ring) >= size))
+		return 0;
+	return __i40e_maybe_stop_tx(tx_ring, size);
+}
+
+/**
+ * i40e_xmit_descriptor_count - calculate number of tx descriptors needed
+ * @skb:     send buffer
+ * @tx_ring: ring to send buffer on
+ *
+ * Returns number of data descriptors needed for this skb. Returns 0 to indicate
+ * there is not enough descriptors available in this ring since we need at least
+ * one descriptor.
+ **/
+static int i40e_xmit_descriptor_count(struct sk_buff *skb,
+				      struct i40e_ring *tx_ring)
+{
+#if PAGE_SIZE > I40E_MAX_DATA_PER_TXD
+	unsigned int f;
+#endif
+	int count = 0;
+
+	/* need: 1 descriptor per page * PAGE_SIZE/I40E_MAX_DATA_PER_TXD,
+	 *       + 1 desc for skb_head_len/I40E_MAX_DATA_PER_TXD,
+	 *       + 2 desc gap to keep tail from touching head,
+	 *       + 1 desc for context descriptor,
+	 * otherwise try next time
+	 */
+#if PAGE_SIZE > I40E_MAX_DATA_PER_TXD
+	for (f = 0; f < skb_shinfo(skb)->nr_frags; f++)
+		count += TXD_USE_COUNT(skb_shinfo(skb)->frags[f].size);
+#else
+	count += skb_shinfo(skb)->nr_frags;
+#endif
+	count += TXD_USE_COUNT(skb_headlen(skb));
+	if (i40e_maybe_stop_tx(tx_ring, count + 3)) {
+		tx_ring->tx_stats.tx_busy++;
+		return 0;
+	}
+	return count;
+}
+
+/**
+ * i40e_xmit_frame_ring - Sends buffer on Tx ring
+ * @skb:     send buffer
+ * @tx_ring: ring to send buffer on
+ *
+ * Returns NETDEV_TX_OK if sent, else an error code
+ **/
+static netdev_tx_t i40e_xmit_frame_ring(struct sk_buff *skb,
+					struct i40e_ring *tx_ring)
+{
+	u64 cd_type_cmd_tso_mss = I40E_TX_DESC_DTYPE_CONTEXT;
+	u32 cd_tunneling = 0, cd_l2tag2 = 0;
+	struct i40e_tx_buffer *first;
+	u32 td_offset = 0;
+	u32 tx_flags = 0;
+	__be16 protocol;
+	u32 td_cmd = 0;
+	u8 hdr_len = 0;
+	int tso;
+	if (0 == i40e_xmit_descriptor_count(skb, tx_ring))
+		return NETDEV_TX_BUSY;
+
+	/* prepare the xmit flags */
+	if (i40e_tx_prepare_vlan_flags(skb, tx_ring, &tx_flags))
+		goto out_drop;
+
+	/* obtain protocol of skb */
+	protocol = skb->protocol;
+
+	/* record the location of the first descriptor for this packet */
+	first = &tx_ring->tx_bi[tx_ring->next_to_use];
+
+	/* setup IPv4/IPv6 offloads */
+	if (protocol == htons(ETH_P_IP))
+		tx_flags |= I40E_TX_FLAGS_IPV4;
+	else if (protocol == htons(ETH_P_IPV6))
+		tx_flags |= I40E_TX_FLAGS_IPV6;
+
+	tso = i40e_tso(tx_ring, skb, tx_flags, protocol, &hdr_len,
+		       &cd_type_cmd_tso_mss, &cd_tunneling);
+
+	if (tso < 0)
+		goto out_drop;
+	else if (tso)
+		tx_flags |= I40E_TX_FLAGS_TSO;
+
+	skb_tx_timestamp(skb);
+
+	/* always enable CRC insertion offload */
+	td_cmd |= I40E_TX_DESC_CMD_ICRC;
+
+	/* Always offload the checksum, since it's in the data descriptor */
+	if (skb->ip_summed == CHECKSUM_PARTIAL) {
+		tx_flags |= I40E_TX_FLAGS_CSUM;
+
+		i40e_tx_enable_csum(skb, tx_flags, &td_cmd, &td_offset,
+				    tx_ring, &cd_tunneling);
+	}
+
+	i40e_create_tx_ctx(tx_ring, cd_type_cmd_tso_mss,
+			   cd_tunneling, cd_l2tag2);
+
+	i40e_tx_map(tx_ring, skb, first, tx_flags, hdr_len,
+		    td_cmd, td_offset);
+
+	i40e_maybe_stop_tx(tx_ring, DESC_NEEDED);
+
+	return NETDEV_TX_OK;
+
+out_drop:
+	dev_kfree_skb_any(skb);
+	return NETDEV_TX_OK;
+}
+
+/**
+ * i40evf_xmit_frame - Selects the correct VSI and Tx queue to send buffer
+ * @skb:    send buffer
+ * @netdev: network interface device structure
+ *
+ * Returns NETDEV_TX_OK if sent, else an error code
+ **/
+netdev_tx_t i40evf_xmit_frame(struct sk_buff *skb, struct net_device *netdev)
+{
+	struct i40evf_adapter *adapter = netdev_priv(netdev);
+	struct i40e_ring *tx_ring = adapter->tx_rings[skb->queue_mapping];
+
+	/* hardware can't handle really short frames, hardware padding works
+	 * beyond this point
+	 */
+	if (unlikely(skb->len < I40E_MIN_TX_LEN)) {
+		if (skb_pad(skb, I40E_MIN_TX_LEN - skb->len))
+			return NETDEV_TX_OK;
+		skb->len = I40E_MIN_TX_LEN;
+		skb_set_tail_pointer(skb, I40E_MIN_TX_LEN);
+	}
+
+	return i40e_xmit_frame_ring(skb, tx_ring);
+}