sfc: Record hardware RX hash on each skb where possible

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/sfc/rx.c b/drivers/net/sfc/rx.c
index d9ed20e..0fb9835 100644
--- a/drivers/net/sfc/rx.c
+++ b/drivers/net/sfc/rx.c
@@ -101,6 +101,19 @@
 	return PAGE_SIZE << efx->rx_buffer_order;
 }
 
+static inline u32 efx_rx_buf_hash(struct efx_rx_buffer *buf)
+{
+#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) || NET_IP_ALIGN % 4 == 0
+	return __le32_to_cpup((const __le32 *)buf->data);
+#else
+	const u8 *data = (const u8 *)buf->data;
+	return ((u32)data[0]       |
+		(u32)data[1] << 8  |
+		(u32)data[2] << 16 |
+		(u32)data[3] << 24);
+#endif
+}
+
 /**
  * efx_init_rx_buffers_skb - create EFX_RX_BATCH skb-based RX buffers
  *
@@ -441,6 +454,7 @@
 
 	/* Pass the skb/page into the LRO engine */
 	if (rx_buf->page) {
+		struct efx_nic *efx = channel->efx;
 		struct page *page = rx_buf->page;
 		struct sk_buff *skb;
 
@@ -453,6 +467,11 @@
 			return;
 		}
 
+		if (efx->net_dev->features & NETIF_F_RXHASH)
+			skb->rxhash = efx_rx_buf_hash(rx_buf);
+		rx_buf->data += efx->type->rx_buffer_hash_size;
+		rx_buf->len -= efx->type->rx_buffer_hash_size;
+
 		skb_shinfo(skb)->frags[0].page = page;
 		skb_shinfo(skb)->frags[0].page_offset =
 			efx_rx_buf_offset(rx_buf);
@@ -572,6 +591,10 @@
 
 		skb_put(rx_buf->skb, rx_buf->len);
 
+		if (efx->net_dev->features & NETIF_F_RXHASH)
+			rx_buf->skb->rxhash = efx_rx_buf_hash(rx_buf);
+		skb_pull(rx_buf->skb, efx->type->rx_buffer_hash_size);
+
 		/* Move past the ethernet header. rx_buf->data still points
 		 * at the ethernet header */
 		rx_buf->skb->protocol = eth_type_trans(rx_buf->skb,