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-rw-r--r--drivers/net/ethernet/intel/i40e/i40e_txrx.c47
-rw-r--r--drivers/net/ethernet/intel/i40evf/i40e_txrx.c47
2 files changed, 94 insertions, 0 deletions
diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.c b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
index f15e1bcf3555..20691d2bf113 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_txrx.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
@@ -1816,6 +1816,51 @@ static struct sk_buff *i40e_construct_skb(struct i40e_ring *rx_ring,
}
/**
+ * 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(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;
+}
+
+/**
* 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
@@ -1939,6 +1984,8 @@ static int i40e_clean_rx_irq(struct i40e_ring *rx_ring, int budget)
/* 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);
diff --git a/drivers/net/ethernet/intel/i40evf/i40e_txrx.c b/drivers/net/ethernet/intel/i40evf/i40e_txrx.c
index a71f81a9291f..460171edc412 100644
--- a/drivers/net/ethernet/intel/i40evf/i40e_txrx.c
+++ b/drivers/net/ethernet/intel/i40evf/i40e_txrx.c
@@ -1177,6 +1177,51 @@ static struct sk_buff *i40e_construct_skb(struct i40e_ring *rx_ring,
}
/**
+ * 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(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;
+}
+
+/**
* 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
@@ -1295,6 +1340,8 @@ static int i40e_clean_rx_irq(struct i40e_ring *rx_ring, int budget)
/* 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);