1 files changed, 359 insertions, 269 deletions

diff --git a/drivers/net/ethernet/intel/i40evf/i40e_txrx.c b/drivers/net/ethernet/intel/i40evf/i40e_txrx.c
index df67ef37b7f3..12b02e530503 100644
--- a/drivers/net/ethernet/intel/i40evf/i40e_txrx.c
+++ b/drivers/net/ethernet/intel/i40evf/i40e_txrx.c
@@ -28,6 +28,7 @@
 #include <net/busy_poll.h>
 
 #include "i40evf.h"
+#include "i40e_trace.h"
 #include "i40e_prototype.h"
 
 static inline __le64 build_ctob(u32 td_cmd, u32 td_offset, unsigned int size,
@@ -137,10 +138,7 @@ u32 i40evf_get_tx_pending(struct i40e_ring *ring, bool in_sw)
 {
 	u32 head, tail;
 
-	if (!in_sw)
-		head = i40e_get_head(ring);
-	else
-		head = ring->next_to_clean;
+	head = ring->next_to_clean;
 	tail = readl(ring->tail);
 
 	if (head != tail)
@@ -165,7 +163,6 @@ static bool i40e_clean_tx_irq(struct i40e_vsi *vsi,
 {
 	u16 i = tx_ring->next_to_clean;
 	struct i40e_tx_buffer *tx_buf;
-	struct i40e_tx_desc *tx_head;
 	struct i40e_tx_desc *tx_desc;
 	unsigned int total_bytes = 0, total_packets = 0;
 	unsigned int budget = vsi->work_limit;
@@ -174,8 +171,6 @@ static bool i40e_clean_tx_irq(struct i40e_vsi *vsi,
 	tx_desc = I40E_TX_DESC(tx_ring, i);
 	i -= tx_ring->count;
 
-	tx_head = I40E_TX_DESC(tx_ring, i40e_get_head(tx_ring));
-
 	do {
 		struct i40e_tx_desc *eop_desc = tx_buf->next_to_watch;
 
@@ -186,8 +181,10 @@ static bool i40e_clean_tx_irq(struct i40e_vsi *vsi,
 		/* prevent any other reads prior to eop_desc */
 		read_barrier_depends();
 
-		/* we have caught up to head, no work left to do */
-		if (tx_head == tx_desc)
+		i40e_trace(clean_tx_irq, tx_ring, tx_desc, tx_buf);
+		/* 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 */
@@ -212,6 +209,8 @@ static bool i40e_clean_tx_irq(struct i40e_vsi *vsi,
 
 		/* unmap remaining buffers */
 		while (tx_desc != eop_desc) {
+			i40e_trace(clean_tx_irq_unmap,
+				   tx_ring, tx_desc, tx_buf);
 
 			tx_buf++;
 			tx_desc++;
@@ -267,7 +266,7 @@ static bool i40e_clean_tx_irq(struct i40e_vsi *vsi,
 
 		if (budget &&
 		    ((j / WB_STRIDE) == 0) && (j > 0) &&
-		    !test_bit(__I40E_DOWN, &vsi->state) &&
+		    !test_bit(__I40E_VSI_DOWN, vsi->state) &&
 		    (I40E_DESC_UNUSED(tx_ring) != tx_ring->count))
 			tx_ring->arm_wb = true;
 	}
@@ -285,7 +284,7 @@ static bool i40e_clean_tx_irq(struct i40e_vsi *vsi,
 		smp_mb();
 		if (__netif_subqueue_stopped(tx_ring->netdev,
 					     tx_ring->queue_index) &&
-		   !test_bit(__I40E_DOWN, &vsi->state)) {
+		   !test_bit(__I40E_VSI_DOWN, vsi->state)) {
 			netif_wake_subqueue(tx_ring->netdev,
 					    tx_ring->queue_index);
 			++tx_ring->tx_stats.restart_queue;
@@ -464,10 +463,6 @@ int i40evf_setup_tx_descriptors(struct i40e_ring *tx_ring)
 
 	/* round up to nearest 4K */
 	tx_ring->size = tx_ring->count * sizeof(struct i40e_tx_desc);
-	/* add u32 for head writeback, align after this takes care of
-	 * guaranteeing this is at least one cache line in size
-	 */
-	tx_ring->size += sizeof(u32);
 	tx_ring->size = ALIGN(tx_ring->size, 4096);
 	tx_ring->desc = dma_alloc_coherent(dev, tx_ring->size,
 					   &tx_ring->dma, GFP_KERNEL);
@@ -493,7 +488,6 @@ err:
  **/
 void i40evf_clean_rx_ring(struct i40e_ring *rx_ring)
 {
-	struct device *dev = rx_ring->dev;
 	unsigned long bi_size;
 	u16 i;
 
@@ -501,19 +495,34 @@ void i40evf_clean_rx_ring(struct i40e_ring *rx_ring)
 	if (!rx_ring->rx_bi)
 		return;
 
+	if (rx_ring->skb) {
+		dev_kfree_skb(rx_ring->skb);
+		rx_ring->skb = NULL;
+	}
+
 	/* Free all the Rx ring sk_buffs */
 	for (i = 0; i < rx_ring->count; i++) {
 		struct i40e_rx_buffer *rx_bi = &rx_ring->rx_bi[i];
 
-		if (rx_bi->skb) {
-			dev_kfree_skb(rx_bi->skb);
-			rx_bi->skb = NULL;
-		}
 		if (!rx_bi->page)
 			continue;
 
-		dma_unmap_page(dev, rx_bi->dma, PAGE_SIZE, DMA_FROM_DEVICE);
-		__free_pages(rx_bi->page, 0);
+		/* Invalidate cache lines that may have been written to by
+		 * device so that we avoid corrupting memory.
+		 */
+		dma_sync_single_range_for_cpu(rx_ring->dev,
+					      rx_bi->dma,
+					      rx_bi->page_offset,
+					      rx_ring->rx_buf_len,
+					      DMA_FROM_DEVICE);
+
+		/* free resources associated with mapping */
+		dma_unmap_page_attrs(rx_ring->dev, rx_bi->dma,
+				     i40e_rx_pg_size(rx_ring),
+				     DMA_FROM_DEVICE,
+				     I40E_RX_DMA_ATTR);
+
+		__page_frag_cache_drain(rx_bi->page, rx_bi->pagecnt_bias);
 
 		rx_bi->page = NULL;
 		rx_bi->page_offset = 0;
@@ -614,6 +623,17 @@ static inline void i40e_release_rx_desc(struct i40e_ring *rx_ring, u32 val)
 }
 
 /**
+ * i40e_rx_offset - Return expected offset into page to access data
+ * @rx_ring: Ring we are requesting offset of
+ *
+ * Returns the offset value for ring into the data buffer.
+ */
+static inline unsigned int i40e_rx_offset(struct i40e_ring *rx_ring)
+{
+	return ring_uses_build_skb(rx_ring) ? I40E_SKB_PAD : 0;
+}
+
+/**
  * i40e_alloc_mapped_page - recycle or make a new page
  * @rx_ring: ring to use
  * @bi: rx_buffer struct to modify
@@ -634,27 +654,33 @@ static bool i40e_alloc_mapped_page(struct i40e_ring *rx_ring,
 	}
 
 	/* alloc new page for storage */
-	page = dev_alloc_page();
+	page = dev_alloc_pages(i40e_rx_pg_order(rx_ring));
 	if (unlikely(!page)) {
 		rx_ring->rx_stats.alloc_page_failed++;
 		return false;
 	}
 
 	/* map page for use */
-	dma = dma_map_page(rx_ring->dev, page, 0, PAGE_SIZE, DMA_FROM_DEVICE);
+	dma = dma_map_page_attrs(rx_ring->dev, page, 0,
+				 i40e_rx_pg_size(rx_ring),
+				 DMA_FROM_DEVICE,
+				 I40E_RX_DMA_ATTR);
 
 	/* if mapping failed free memory back to system since
 	 * there isn't much point in holding memory we can't use
 	 */
 	if (dma_mapping_error(rx_ring->dev, dma)) {
-		__free_pages(page, 0);
+		__free_pages(page, i40e_rx_pg_order(rx_ring));
 		rx_ring->rx_stats.alloc_page_failed++;
 		return false;
 	}
 
 	bi->dma = dma;
 	bi->page = page;
-	bi->page_offset = 0;
+	bi->page_offset = i40e_rx_offset(rx_ring);
+
+	/* initialize pagecnt_bias to 1 representing we fully own page */
+	bi->pagecnt_bias = 1;
 
 	return true;
 }
@@ -701,6 +727,12 @@ bool i40evf_alloc_rx_buffers(struct i40e_ring *rx_ring, u16 cleaned_count)
 		if (!i40e_alloc_mapped_page(rx_ring, bi))
 			goto no_buffers;
 
+		/* sync the buffer for use by the device */
+		dma_sync_single_range_for_device(rx_ring->dev, bi->dma,
+						 bi->page_offset,
+						 rx_ring->rx_buf_len,
+						 DMA_FROM_DEVICE);
+
 		/* Refresh the desc even if buffer_addrs didn't change
 		 * because each write-back erases this info.
 		 */
@@ -741,8 +773,6 @@ no_buffers:
  * @vsi: the VSI we care about
  * @skb: skb currently being received and modified
  * @rx_desc: the receive descriptor
- *
- * skb->protocol must be set before this function is called
  **/
 static inline void i40e_rx_checksum(struct i40e_vsi *vsi,
 				    struct sk_buff *skb,
@@ -805,13 +835,6 @@ static inline void i40e_rx_checksum(struct i40e_vsi *vsi,
 	if (rx_error & BIT(I40E_RX_DESC_ERROR_PPRS_SHIFT))
 		return;
 
-	/* If there is an outer header present that might contain a checksum
-	 * we need to bump the checksum level by 1 to reflect the fact that
-	 * we are indicating we validated the inner checksum.
-	 */
-	if (decoded.tunnel_type >= I40E_RX_PTYPE_TUNNEL_IP_GRENAT)
-		skb->csum_level = 1;
-
 	/* Only report checksum unnecessary for TCP, UDP, or SCTP */
 	switch (decoded.inner_prot) {
 	case I40E_RX_PTYPE_INNER_PROT_TCP:
@@ -894,51 +917,12 @@ void i40evf_process_skb_fields(struct i40e_ring *rx_ring,
 {
 	i40e_rx_hash(rx_ring, rx_desc, skb, rx_ptype);
 
-	/* modifies the skb - consumes the enet header */
-	skb->protocol = eth_type_trans(skb, rx_ring->netdev);
-
 	i40e_rx_checksum(rx_ring->vsi, skb, rx_desc);
 
 	skb_record_rx_queue(skb, rx_ring->queue_index);
-}
-
-/**
- * i40e_pull_tail - i40e specific version of skb_pull_tail
- * @rx_ring: rx descriptor ring packet is being transacted on
- * @skb: pointer to current skb being adjusted
- *
- * This function is an i40e specific version of __pskb_pull_tail.  The
- * main difference between this version and the original function is that
- * this function can make several assumptions about the state of things
- * that allow for significant optimizations versus the standard function.
- * As a result we can do things like drop a frag and maintain an accurate
- * truesize for the skb.
- */
-static void i40e_pull_tail(struct i40e_ring *rx_ring, struct sk_buff *skb)
-{
-	struct skb_frag_struct *frag = &skb_shinfo(skb)->frags[0];
-	unsigned char *va;
-	unsigned int pull_len;
-
-	/* it is valid to use page_address instead of kmap since we are
-	 * working with pages allocated out of the lomem pool per
-	 * alloc_page(GFP_ATOMIC)
-	 */
-	va = skb_frag_address(frag);
-
-	/* we need the header to contain the greater of either ETH_HLEN or
-	 * 60 bytes if the skb->len is less than 60 for skb_pad.
-	 */
-	pull_len = eth_get_headlen(va, I40E_RX_HDR_SIZE);
-
-	/* align pull length to size of long to optimize memcpy performance */
-	skb_copy_to_linear_data(skb, va, ALIGN(pull_len, sizeof(long)));
 
-	/* update all of the pointers */
-	skb_frag_size_sub(frag, pull_len);
-	frag->page_offset += pull_len;
-	skb->data_len -= pull_len;
-	skb->tail += pull_len;
+	/* modifies the skb - consumes the enet header */
+	skb->protocol = eth_type_trans(skb, rx_ring->netdev);
 }
 
 /**
@@ -956,10 +940,6 @@ static void i40e_pull_tail(struct i40e_ring *rx_ring, struct sk_buff *skb)
  **/
 static bool i40e_cleanup_headers(struct i40e_ring *rx_ring, struct sk_buff *skb)
 {
-	/* place header in linear portion of buffer */
-	if (skb_is_nonlinear(skb))
-		i40e_pull_tail(rx_ring, skb);
-
 	/* if eth_skb_pad returns an error the skb was freed */
 	if (eth_skb_pad(skb))
 		return true;
@@ -987,169 +967,284 @@ static void i40e_reuse_rx_page(struct i40e_ring *rx_ring,
 	rx_ring->next_to_alloc = (nta < rx_ring->count) ? nta : 0;
 
 	/* transfer page from old buffer to new buffer */
-	*new_buff = *old_buff;
+	new_buff->dma		= old_buff->dma;
+	new_buff->page		= old_buff->page;
+	new_buff->page_offset	= old_buff->page_offset;
+	new_buff->pagecnt_bias	= old_buff->pagecnt_bias;
 }
 
 /**
- * i40e_page_is_reserved - check if reuse is possible
+ * i40e_page_is_reusable - check if any reuse is possible
  * @page: page struct to check
+ *
+ * A page is not reusable if it was allocated under low memory
+ * conditions, or it's not in the same NUMA node as this CPU.
  */
-static inline bool i40e_page_is_reserved(struct page *page)
+static inline bool i40e_page_is_reusable(struct page *page)
 {
-	return (page_to_nid(page) != numa_mem_id()) || page_is_pfmemalloc(page);
+	return (page_to_nid(page) == numa_mem_id()) &&
+		!page_is_pfmemalloc(page);
+}
+
+/**
+ * i40e_can_reuse_rx_page - Determine if this page can be reused by
+ * the adapter for another receive
+ *
+ * @rx_buffer: buffer containing the page
+ *
+ * If page is reusable, rx_buffer->page_offset is adjusted to point to
+ * an unused region in the page.
+ *
+ * For small pages, @truesize will be a constant value, half the size
+ * of the memory at page.  We'll attempt to alternate between high and
+ * low halves of the page, with one half ready for use by the hardware
+ * and the other half being consumed by the stack.  We use the page
+ * ref count to determine whether the stack has finished consuming the
+ * portion of this page that was passed up with a previous packet.  If
+ * the page ref count is >1, we'll assume the "other" half page is
+ * still busy, and this page cannot be reused.
+ *
+ * For larger pages, @truesize will be the actual space used by the
+ * received packet (adjusted upward to an even multiple of the cache
+ * line size).  This will advance through the page by the amount
+ * actually consumed by the received packets while there is still
+ * space for a buffer.  Each region of larger pages will be used at
+ * most once, after which the page will not be reused.
+ *
+ * In either case, if the page is reusable its refcount is increased.
+ **/
+static bool i40e_can_reuse_rx_page(struct i40e_rx_buffer *rx_buffer)
+{
+	unsigned int pagecnt_bias = rx_buffer->pagecnt_bias;
+	struct page *page = rx_buffer->page;
+
+	/* Is any reuse possible? */
+	if (unlikely(!i40e_page_is_reusable(page)))
+		return false;
+
+#if (PAGE_SIZE < 8192)
+	/* if we are only owner of page we can reuse it */
+	if (unlikely((page_count(page) - pagecnt_bias) > 1))
+		return false;
+#else
+#define I40E_LAST_OFFSET \
+	(SKB_WITH_OVERHEAD(PAGE_SIZE) - I40E_RXBUFFER_2048)
+	if (rx_buffer->page_offset > I40E_LAST_OFFSET)
+		return false;
+#endif
+
+	/* If we have drained the page fragment pool we need to update
+	 * the pagecnt_bias and page count so that we fully restock the
+	 * number of references the driver holds.
+	 */
+	if (unlikely(!pagecnt_bias)) {
+		page_ref_add(page, USHRT_MAX);
+		rx_buffer->pagecnt_bias = USHRT_MAX;
+	}
+
+	return true;
 }
 
 /**
  * i40e_add_rx_frag - Add contents of Rx buffer to sk_buff
  * @rx_ring: rx descriptor ring to transact packets on
  * @rx_buffer: buffer containing page to add
- * @rx_desc: descriptor containing length of buffer written by hardware
  * @skb: sk_buff to place the data into
+ * @size: packet length from rx_desc
  *
  * This function will add the data contained in rx_buffer->page to the skb.
- * This is done either through a direct copy if the data in the buffer is
- * less than the skb header size, otherwise it will just attach the page as
- * a frag to the skb.
+ * It will just attach the page as a frag to the skb.
  *
- * The function will then update the page offset if necessary and return
- * true if the buffer can be reused by the adapter.
+ * The function will then update the page offset.
  **/
-static bool i40e_add_rx_frag(struct i40e_ring *rx_ring,
+static void i40e_add_rx_frag(struct i40e_ring *rx_ring,
 			     struct i40e_rx_buffer *rx_buffer,
-			     union i40e_rx_desc *rx_desc,
-			     struct sk_buff *skb)
+			     struct sk_buff *skb,
+			     unsigned int size)
 {
-	struct page *page = rx_buffer->page;
-	u64 qword = le64_to_cpu(rx_desc->wb.qword1.status_error_len);
-	unsigned int size = (qword & I40E_RXD_QW1_LENGTH_PBUF_MASK) >>
-			    I40E_RXD_QW1_LENGTH_PBUF_SHIFT;
 #if (PAGE_SIZE < 8192)
-	unsigned int truesize = I40E_RXBUFFER_2048;
+	unsigned int truesize = i40e_rx_pg_size(rx_ring) / 2;
 #else
-	unsigned int truesize = ALIGN(size, L1_CACHE_BYTES);
-	unsigned int last_offset = PAGE_SIZE - I40E_RXBUFFER_2048;
+	unsigned int truesize = SKB_DATA_ALIGN(size + i40e_rx_offset(rx_ring));
 #endif
 
-	/* will the data fit in the skb we allocated? if so, just
-	 * copy it as it is pretty small anyway
-	 */
-	if ((size <= I40E_RX_HDR_SIZE) && !skb_is_nonlinear(skb)) {
-		unsigned char *va = page_address(page) + rx_buffer->page_offset;
-
-		memcpy(__skb_put(skb, size), va, ALIGN(size, sizeof(long)));
-
-		/* page is not reserved, we can reuse buffer as-is */
-		if (likely(!i40e_page_is_reserved(page)))
-			return true;
-
-		/* this page cannot be reused so discard it */
-		__free_pages(page, 0);
-		return false;
-	}
-
-	skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, page,
+	skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, rx_buffer->page,
 			rx_buffer->page_offset, size, truesize);
 
-	/* avoid re-using remote pages */
-	if (unlikely(i40e_page_is_reserved(page)))
-		return false;
-
+	/* page is being used so we must update the page offset */
 #if (PAGE_SIZE < 8192)
-	/* if we are only owner of page we can reuse it */
-	if (unlikely(page_count(page) != 1))
-		return false;
-
-	/* flip page offset to other buffer */
 	rx_buffer->page_offset ^= truesize;
 #else
-	/* move offset up to the next cache line */
 	rx_buffer->page_offset += truesize;
-
-	if (rx_buffer->page_offset > last_offset)
-		return false;
 #endif
-
-	/* Even if we own the page, we are not allowed to use atomic_set()
-	 * This would break get_page_unless_zero() users.
-	 */
-	get_page(rx_buffer->page);
-
-	return true;
 }
 
 /**
- * i40evf_fetch_rx_buffer - Allocate skb and populate it
+ * i40e_get_rx_buffer - Fetch Rx buffer and synchronize data for use
  * @rx_ring: rx descriptor ring to transact packets on
- * @rx_desc: descriptor containing info written by hardware
+ * @size: size of buffer to add to skb
  *
- * This function allocates an skb on the fly, and populates it with the page
- * data from the current receive descriptor, taking care to set up the skb
- * correctly, as well as handling calling the page recycle function if
- * necessary.
+ * This function will pull an Rx buffer from the ring and synchronize it
+ * for use by the CPU.
  */
-static inline
-struct sk_buff *i40evf_fetch_rx_buffer(struct i40e_ring *rx_ring,
-				       union i40e_rx_desc *rx_desc)
+static struct i40e_rx_buffer *i40e_get_rx_buffer(struct i40e_ring *rx_ring,
+						 const unsigned int size)
 {
 	struct i40e_rx_buffer *rx_buffer;
-	struct sk_buff *skb;
-	struct page *page;
 
 	rx_buffer = &rx_ring->rx_bi[rx_ring->next_to_clean];
-	page = rx_buffer->page;
-	prefetchw(page);
+	prefetchw(rx_buffer->page);
 
-	skb = rx_buffer->skb;
+	/* we are reusing so sync this buffer for CPU use */
+	dma_sync_single_range_for_cpu(rx_ring->dev,
+				      rx_buffer->dma,
+				      rx_buffer->page_offset,
+				      size,
+				      DMA_FROM_DEVICE);
 
-	if (likely(!skb)) {
-		void *page_addr = page_address(page) + rx_buffer->page_offset;
+	/* We have pulled a buffer for use, so decrement pagecnt_bias */
+	rx_buffer->pagecnt_bias--;
 
-		/* prefetch first cache line of first page */
-		prefetch(page_addr);
+	return rx_buffer;
+}
+
+/**
+ * i40e_construct_skb - Allocate skb and populate it
+ * @rx_ring: rx descriptor ring to transact packets on
+ * @rx_buffer: rx buffer to pull data from
+ * @size: size of buffer to add to skb
+ *
+ * This function allocates an skb.  It then populates it with the page
+ * data from the current receive descriptor, taking care to set up the
+ * skb correctly.
+ */
+static struct sk_buff *i40e_construct_skb(struct i40e_ring *rx_ring,
+					  struct i40e_rx_buffer *rx_buffer,
+					  unsigned int size)
+{
+	void *va = page_address(rx_buffer->page) + rx_buffer->page_offset;
+#if (PAGE_SIZE < 8192)
+	unsigned int truesize = i40e_rx_pg_size(rx_ring) / 2;
+#else
+	unsigned int truesize = SKB_DATA_ALIGN(size);
+#endif
+	unsigned int headlen;
+	struct sk_buff *skb;
+
+	/* prefetch first cache line of first page */
+	prefetch(va);
 #if L1_CACHE_BYTES < 128
-		prefetch(page_addr + L1_CACHE_BYTES);
+	prefetch(va + L1_CACHE_BYTES);
 #endif
 
-		/* allocate a skb to store the frags */
-		skb = __napi_alloc_skb(&rx_ring->q_vector->napi,
-				       I40E_RX_HDR_SIZE,
-				       GFP_ATOMIC | __GFP_NOWARN);
-		if (unlikely(!skb)) {
-			rx_ring->rx_stats.alloc_buff_failed++;
-			return NULL;
-		}
+	/* allocate a skb to store the frags */
+	skb = __napi_alloc_skb(&rx_ring->q_vector->napi,
+			       I40E_RX_HDR_SIZE,
+			       GFP_ATOMIC | __GFP_NOWARN);
+	if (unlikely(!skb))
+		return NULL;
 
-		/* we will be copying header into skb->data in
-		 * pskb_may_pull so it is in our interest to prefetch
-		 * it now to avoid a possible cache miss
-		 */
-		prefetchw(skb->data);
+	/* Determine available headroom for copy */
+	headlen = size;
+	if (headlen > I40E_RX_HDR_SIZE)
+		headlen = eth_get_headlen(va, I40E_RX_HDR_SIZE);
+
+	/* align pull length to size of long to optimize memcpy performance */
+	memcpy(__skb_put(skb, headlen), va, ALIGN(headlen, sizeof(long)));
+
+	/* update all of the pointers */
+	size -= headlen;
+	if (size) {
+		skb_add_rx_frag(skb, 0, rx_buffer->page,
+				rx_buffer->page_offset + headlen,
+				size, truesize);
+
+		/* buffer is used by skb, update page_offset */
+#if (PAGE_SIZE < 8192)
+		rx_buffer->page_offset ^= truesize;
+#else
+		rx_buffer->page_offset += truesize;
+#endif
 	} else {
-		rx_buffer->skb = NULL;
+		/* buffer is unused, reset bias back to rx_buffer */
+		rx_buffer->pagecnt_bias++;
 	}
 
-	/* we are reusing so sync this buffer for CPU use */
-	dma_sync_single_range_for_cpu(rx_ring->dev,
-				      rx_buffer->dma,
-				      rx_buffer->page_offset,
-				      I40E_RXBUFFER_2048,
-				      DMA_FROM_DEVICE);
+	return skb;
+}
+
+/**
+ * i40e_build_skb - Build skb around an existing buffer
+ * @rx_ring: Rx descriptor ring to transact packets on
+ * @rx_buffer: Rx buffer to pull data from
+ * @size: size of buffer to add to skb
+ *
+ * This function builds an skb around an existing Rx buffer, taking care
+ * to set up the skb correctly and avoid any memcpy overhead.
+ */
+static struct sk_buff *i40e_build_skb(struct i40e_ring *rx_ring,
+				      struct i40e_rx_buffer *rx_buffer,
+				      unsigned int size)
+{
+	void *va = page_address(rx_buffer->page) + rx_buffer->page_offset;
+#if (PAGE_SIZE < 8192)
+	unsigned int truesize = i40e_rx_pg_size(rx_ring) / 2;
+#else
+	unsigned int truesize = SKB_DATA_ALIGN(sizeof(struct skb_shared_info)) +
+				SKB_DATA_ALIGN(I40E_SKB_PAD + size);
+#endif
+	struct sk_buff *skb;
+
+	/* prefetch first cache line of first page */
+	prefetch(va);
+#if L1_CACHE_BYTES < 128
+	prefetch(va + L1_CACHE_BYTES);
+#endif
+	/* build an skb around the page buffer */
+	skb = build_skb(va - I40E_SKB_PAD, truesize);
+	if (unlikely(!skb))
+		return NULL;
+
+	/* update pointers within the skb to store the data */
+	skb_reserve(skb, I40E_SKB_PAD);
+	__skb_put(skb, size);
+
+	/* buffer is used by skb, update page_offset */
+#if (PAGE_SIZE < 8192)
+	rx_buffer->page_offset ^= truesize;
+#else
+	rx_buffer->page_offset += truesize;
+#endif
+
+	return skb;
+}
 
-	/* pull page into skb */
-	if (i40e_add_rx_frag(rx_ring, rx_buffer, rx_desc, skb)) {
+/**
+ * i40e_put_rx_buffer - Clean up used buffer and either recycle or free
+ * @rx_ring: rx descriptor ring to transact packets on
+ * @rx_buffer: rx buffer to pull data from
+ *
+ * This function will clean up the contents of the rx_buffer.  It will
+ * either recycle the bufer or unmap it and free the associated resources.
+ */
+static void i40e_put_rx_buffer(struct i40e_ring *rx_ring,
+			       struct i40e_rx_buffer *rx_buffer)
+{
+	if (i40e_can_reuse_rx_page(rx_buffer)) {
 		/* hand second half of page back to the ring */
 		i40e_reuse_rx_page(rx_ring, rx_buffer);
 		rx_ring->rx_stats.page_reuse_count++;
 	} else {
 		/* we are not reusing the buffer so unmap it */
-		dma_unmap_page(rx_ring->dev, rx_buffer->dma, PAGE_SIZE,
-			       DMA_FROM_DEVICE);
+		dma_unmap_page_attrs(rx_ring->dev, rx_buffer->dma,
+				     i40e_rx_pg_size(rx_ring),
+				     DMA_FROM_DEVICE, I40E_RX_DMA_ATTR);
+		__page_frag_cache_drain(rx_buffer->page,
+					rx_buffer->pagecnt_bias);
 	}
 
 	/* clear contents of buffer_info */
 	rx_buffer->page = NULL;
-
-	return skb;
 }
 
 /**
@@ -1180,8 +1275,6 @@ static bool i40e_is_non_eop(struct i40e_ring *rx_ring,
 	if (likely(i40e_test_staterr(rx_desc, I40E_RXD_EOF)))
 		return false;
 
-	/* place skb in next buffer to be received */
-	rx_ring->rx_bi[ntc].skb = skb;
 	rx_ring->rx_stats.non_eop_descs++;
 
 	return true;
@@ -1202,12 +1295,14 @@ static bool i40e_is_non_eop(struct i40e_ring *rx_ring,
 static int i40e_clean_rx_irq(struct i40e_ring *rx_ring, int budget)
 {
 	unsigned int total_rx_bytes = 0, total_rx_packets = 0;
+	struct sk_buff *skb = rx_ring->skb;
 	u16 cleaned_count = I40E_DESC_UNUSED(rx_ring);
 	bool failure = false;
 
 	while (likely(total_rx_packets < budget)) {
+		struct i40e_rx_buffer *rx_buffer;
 		union i40e_rx_desc *rx_desc;
-		struct sk_buff *skb;
+		unsigned int size;
 		u16 vlan_tag;
 		u8 rx_ptype;
 		u64 qword;
@@ -1224,22 +1319,40 @@ static int i40e_clean_rx_irq(struct i40e_ring *rx_ring, int budget)
 		/* status_error_len will always be zero for unused descriptors
 		 * because it's cleared in cleanup, and overlaps with hdr_addr
 		 * which is always zero because packet split isn't used, if the
-		 * hardware wrote DD then it will be non-zero
+		 * hardware wrote DD then the length will be non-zero
 		 */
-		if (!i40e_test_staterr(rx_desc,
-				       BIT(I40E_RX_DESC_STATUS_DD_SHIFT)))
-			break;
+		qword = le64_to_cpu(rx_desc->wb.qword1.status_error_len);
 
 		/* This memory barrier is needed to keep us from reading
-		 * any other fields out of the rx_desc until we know the
-		 * DD bit is set.
+		 * any other fields out of the rx_desc until we have
+		 * verified the descriptor has been written back.
 		 */
 		dma_rmb();
 
-		skb = i40evf_fetch_rx_buffer(rx_ring, rx_desc);
-		if (!skb)
+		size = (qword & I40E_RXD_QW1_LENGTH_PBUF_MASK) >>
+		       I40E_RXD_QW1_LENGTH_PBUF_SHIFT;
+		if (!size)
+			break;
+
+		i40e_trace(clean_rx_irq, rx_ring, rx_desc, skb);
+		rx_buffer = i40e_get_rx_buffer(rx_ring, size);
+
+		/* retrieve a buffer from the ring */
+		if (skb)
+			i40e_add_rx_frag(rx_ring, rx_buffer, skb, size);
+		else if (ring_uses_build_skb(rx_ring))
+			skb = i40e_build_skb(rx_ring, rx_buffer, size);
+		else
+			skb = i40e_construct_skb(rx_ring, rx_buffer, size);
+
+		/* exit if we failed to retrieve a buffer */
+		if (!skb) {
+			rx_ring->rx_stats.alloc_buff_failed++;
+			rx_buffer->pagecnt_bias++;
 			break;
+		}
 
+		i40e_put_rx_buffer(rx_ring, rx_buffer);
 		cleaned_count++;
 
 		if (i40e_is_non_eop(rx_ring, rx_desc, skb))
@@ -1252,11 +1365,14 @@ static int i40e_clean_rx_irq(struct i40e_ring *rx_ring, int budget)
 		 */
 		if (unlikely(i40e_test_staterr(rx_desc, BIT(I40E_RXD_QW1_ERROR_SHIFT)))) {
 			dev_kfree_skb_any(skb);
+			skb = NULL;
 			continue;
 		}
 
-		if (i40e_cleanup_headers(rx_ring, skb))
+		if (i40e_cleanup_headers(rx_ring, skb)) {
+			skb = NULL;
 			continue;
+		}
 
 		/* probably a little skewed due to removing CRC */
 		total_rx_bytes += skb->len;
@@ -1272,12 +1388,16 @@ static int i40e_clean_rx_irq(struct i40e_ring *rx_ring, int budget)
 		vlan_tag = (qword & BIT(I40E_RX_DESC_STATUS_L2TAG1P_SHIFT)) ?
 			   le16_to_cpu(rx_desc->wb.qword0.lo_dword.l2tag1) : 0;
 
+		i40e_trace(clean_rx_irq_rx, rx_ring, rx_desc, skb);
 		i40e_receive_skb(rx_ring, skb, vlan_tag);
+		skb = NULL;
 
 		/* update budget accounting */
 		total_rx_packets++;
 	}
 
+	rx_ring->skb = skb;
+
 	u64_stats_update_begin(&rx_ring->syncp);
 	rx_ring->stats.packets += total_rx_packets;
 	rx_ring->stats.bytes += total_rx_bytes;
@@ -1305,18 +1425,18 @@ static u32 i40e_buildreg_itr(const int type, const u16 itr)
 
 /* a small macro to shorten up some long lines */
 #define INTREG I40E_VFINT_DYN_CTLN1
-static inline int get_rx_itr_enabled(struct i40e_vsi *vsi, int idx)
+static inline int get_rx_itr(struct i40e_vsi *vsi, int idx)
 {
 	struct i40evf_adapter *adapter = vsi->back;
 
-	return !!(adapter->rx_rings[idx].rx_itr_setting);
+	return adapter->rx_rings[idx].rx_itr_setting;
 }
 
-static inline int get_tx_itr_enabled(struct i40e_vsi *vsi, int idx)
+static inline int get_tx_itr(struct i40e_vsi *vsi, int idx)
 {
 	struct i40evf_adapter *adapter = vsi->back;
 
-	return !!(adapter->tx_rings[idx].tx_itr_setting);
+	return adapter->tx_rings[idx].tx_itr_setting;
 }
 
 /**
@@ -1342,8 +1462,8 @@ static inline void i40e_update_enable_itr(struct i40e_vsi *vsi,
 	 */
 	rxval = txval = i40e_buildreg_itr(I40E_ITR_NONE, 0);
 
-	rx_itr_setting = get_rx_itr_enabled(vsi, idx);
-	tx_itr_setting = get_tx_itr_enabled(vsi, idx);
+	rx_itr_setting = get_rx_itr(vsi, idx);
+	tx_itr_setting = get_tx_itr(vsi, idx);
 
 	if (q_vector->itr_countdown > 0 ||
 	    (!ITR_IS_DYNAMIC(rx_itr_setting) &&
@@ -1389,7 +1509,7 @@ static inline void i40e_update_enable_itr(struct i40e_vsi *vsi,
 	}
 
 enable_int:
-	if (!test_bit(__I40E_DOWN, &vsi->state))
+	if (!test_bit(__I40E_VSI_DOWN, vsi->state))
 		wr32(hw, INTREG(vector - 1), txval);
 
 	if (q_vector->itr_countdown)
@@ -1418,7 +1538,7 @@ int i40evf_napi_poll(struct napi_struct *napi, int budget)
 	int budget_per_ring;
 	int work_done = 0;
 
-	if (test_bit(__I40E_DOWN, &vsi->state)) {
+	if (test_bit(__I40E_VSI_DOWN, vsi->state)) {
 		napi_complete(napi);
 		return 0;
 	}
@@ -1549,14 +1669,16 @@ out:
 
 /**
  * i40e_tso - set up the tso context descriptor
- * @skb:      ptr to the skb we're sending
+ * @first:    pointer to first Tx buffer for xmit
  * @hdr_len:  ptr to the size of the packet header
  * @cd_type_cmd_tso_mss: Quad Word 1
  *
  * Returns 0 if no TSO can happen, 1 if tso is going, or error
  **/
-static int i40e_tso(struct sk_buff *skb, u8 *hdr_len, u64 *cd_type_cmd_tso_mss)
+static int i40e_tso(struct i40e_tx_buffer *first, u8 *hdr_len,
+		    u64 *cd_type_cmd_tso_mss)
 {
+	struct sk_buff *skb = first->skb;
 	u64 cd_cmd, cd_tso_len, cd_mss;
 	union {
 		struct iphdr *v4;
@@ -1569,6 +1691,7 @@ static int i40e_tso(struct sk_buff *skb, u8 *hdr_len, u64 *cd_type_cmd_tso_mss)
 		unsigned char *hdr;
 	} l4;
 	u32 paylen, l4_offset;
+	u16 gso_segs, gso_size;
 	int err;
 
 	if (skb->ip_summed != CHECKSUM_PARTIAL)
@@ -1607,7 +1730,8 @@ static int i40e_tso(struct sk_buff *skb, u8 *hdr_len, u64 *cd_type_cmd_tso_mss)
 
 			/* remove payload length from outer checksum */
 			paylen = skb->len - l4_offset;
-			csum_replace_by_diff(&l4.udp->check, htonl(paylen));
+			csum_replace_by_diff(&l4.udp->check,
+					     (__force __wsum)htonl(paylen));
 		}
 
 		/* reset pointers to inner headers */
@@ -1628,15 +1752,23 @@ static int i40e_tso(struct sk_buff *skb, u8 *hdr_len, u64 *cd_type_cmd_tso_mss)
 
 	/* remove payload length from inner checksum */
 	paylen = skb->len - l4_offset;
-	csum_replace_by_diff(&l4.tcp->check, htonl(paylen));
+	csum_replace_by_diff(&l4.tcp->check, (__force __wsum)htonl(paylen));
 
 	/* compute length of segmentation header */
 	*hdr_len = (l4.tcp->doff * 4) + l4_offset;
 
+	/* pull values out of skb_shinfo */
+	gso_size = skb_shinfo(skb)->gso_size;
+	gso_segs = skb_shinfo(skb)->gso_segs;
+
+	/* update GSO size and bytecount with header size */
+	first->gso_segs = gso_segs;
+	first->bytecount += (first->gso_segs - 1) * *hdr_len;
+
 	/* 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_mss = gso_size;
 	*cd_type_cmd_tso_mss |= (cd_cmd << I40E_TXD_CTX_QW1_CMD_SHIFT) |
 				(cd_tso_len << I40E_TXD_CTX_QW1_TSO_LEN_SHIFT) |
 				(cd_mss << I40E_TXD_CTX_QW1_MSS_SHIFT);
@@ -1949,8 +2081,6 @@ static inline void i40evf_tx_map(struct i40e_ring *tx_ring, struct sk_buff *skb,
 	u16 i = tx_ring->next_to_use;
 	u32 td_tag = 0;
 	dma_addr_t dma;
-	u16 gso_segs;
-	u16 desc_count = 1;
 
 	if (tx_flags & I40E_TX_FLAGS_HW_VLAN) {
 		td_cmd |= I40E_TX_DESC_CMD_IL2TAG1;
@@ -1958,15 +2088,6 @@ static inline void i40evf_tx_map(struct i40e_ring *tx_ring, struct sk_buff *skb,
 			 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);
@@ -1995,7 +2116,6 @@ static inline void i40evf_tx_map(struct i40e_ring *tx_ring, struct sk_buff *skb,
 
 			tx_desc++;
 			i++;
-			desc_count++;
 
 			if (i == tx_ring->count) {
 				tx_desc = I40E_TX_DESC(tx_ring, 0);
@@ -2017,7 +2137,6 @@ static inline void i40evf_tx_map(struct i40e_ring *tx_ring, struct sk_buff *skb,
 
 		tx_desc++;
 		i++;
-		desc_count++;
 
 		if (i == tx_ring->count) {
 			tx_desc = I40E_TX_DESC(tx_ring, 0);
@@ -2043,46 +2162,8 @@ static inline void i40evf_tx_map(struct i40e_ring *tx_ring, struct sk_buff *skb,
 
 	i40e_maybe_stop_tx(tx_ring, DESC_NEEDED);
 
-	/* write last descriptor with EOP bit */
-	td_cmd |= I40E_TX_DESC_CMD_EOP;
-
-	/* We can OR these values together as they both are checked against
-	 * 4 below and at this point desc_count will be used as a boolean value
-	 * after this if/else block.
-	 */
-	desc_count |= ++tx_ring->packet_stride;
-
-	/* Algorithm to optimize tail and RS bit setting:
-	 * if queue is stopped
-	 *	mark RS bit
-	 *	reset packet counter
-	 * else if xmit_more is supported and is true
-	 *	advance packet counter to 4
-	 *	reset desc_count to 0
-	 *
-	 * if desc_count >= 4
-	 *	mark RS bit
-	 *	reset packet counter
-	 * if desc_count > 0
-	 *	update tail
-	 *
-	 * Note: If there are less than 4 descriptors
-	 * pending and interrupts were disabled the service task will
-	 * trigger a force WB.
-	 */
-	if (netif_xmit_stopped(txring_txq(tx_ring))) {
-		goto do_rs;
-	} else if (skb->xmit_more) {
-		/* set stride to arm on next packet and reset desc_count */
-		tx_ring->packet_stride = WB_STRIDE;
-		desc_count = 0;
-	} else if (desc_count >= WB_STRIDE) {
-do_rs:
-		/* write last descriptor with RS bit set */
-		td_cmd |= I40E_TX_DESC_CMD_RS;
-		tx_ring->packet_stride = 0;
-	}
-
+	/* write last descriptor with RS and EOP bits */
+	td_cmd |= I40E_TXD_CMD;
 	tx_desc->cmd_type_offset_bsz =
 			build_ctob(td_cmd, td_offset, size, td_tag);
 
@@ -2098,7 +2179,7 @@ do_rs:
 	first->next_to_watch = tx_desc;
 
 	/* notify HW of packet */
-	if (desc_count) {
+	if (netif_xmit_stopped(txring_txq(tx_ring)) || !skb->xmit_more) {
 		writel(i, tx_ring->tail);
 
 		/* we need this if more than one processor can write to our tail
@@ -2149,10 +2230,14 @@ static netdev_tx_t i40e_xmit_frame_ring(struct sk_buff *skb,
 	/* prefetch the data, we'll need it later */
 	prefetch(skb->data);
 
+	i40e_trace(xmit_frame_ring, skb, tx_ring);
+
 	count = i40e_xmit_descriptor_count(skb);
 	if (i40e_chk_linearize(skb, count)) {
-		if (__skb_linearize(skb))
-			goto out_drop;
+		if (__skb_linearize(skb)) {
+			dev_kfree_skb_any(skb);
+			return NETDEV_TX_OK;
+		}
 		count = i40e_txd_use_count(skb->len);
 		tx_ring->tx_stats.tx_linearize++;
 	}
@@ -2168,6 +2253,12 @@ static netdev_tx_t i40e_xmit_frame_ring(struct sk_buff *skb,
 		return NETDEV_TX_BUSY;
 	}
 
+	/* record the location of the first descriptor for this packet */
+	first = &tx_ring->tx_bi[tx_ring->next_to_use];
+	first->skb = skb;
+	first->bytecount = skb->len;
+	first->gso_segs = 1;
+
 	/* prepare the xmit flags */
 	if (i40evf_tx_prepare_vlan_flags(skb, tx_ring, &tx_flags))
 		goto out_drop;
@@ -2175,16 +2266,13 @@ static netdev_tx_t i40e_xmit_frame_ring(struct sk_buff *skb,
 	/* obtain protocol of skb */
 	protocol = vlan_get_protocol(skb);
 
-	/* 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(skb, &hdr_len, &cd_type_cmd_tso_mss);
+	tso = i40e_tso(first, &hdr_len, &cd_type_cmd_tso_mss);
 
 	if (tso < 0)
 		goto out_drop;
@@ -2211,7 +2299,9 @@ static netdev_tx_t i40e_xmit_frame_ring(struct sk_buff *skb,
 	return NETDEV_TX_OK;
 
 out_drop:
-	dev_kfree_skb_any(skb);
+	i40e_trace(xmit_frame_ring_drop, first->skb, tx_ring);
+	dev_kfree_skb_any(first->skb);
+	first->skb = NULL;
 	return NETDEV_TX_OK;
 }