svn commit: r297967 - head/sys/ofed/drivers/net/mlx4

[Hans Petter Selasky]

Author: hselasky
Date: Thu Apr 14 14:10:40 2016
New Revision: 297967
URL: https://svnweb.freebsd.org/changeset/base/297967

Log:
  Ensure the received IP header gets 32-bits aligned.
  
  The FreeBSD's TCP/IP stack assumes that the IP-header is 32-bits aligned
  when decoding it. Else unaligned 32-bit memory access can happen, which
  not all processor architectures support.
  
  Sponsored by:	Mellanox Technologies
  MFC after:	1 week

Modified:
  head/sys/ofed/drivers/net/mlx4/en_rx.c
  head/sys/ofed/drivers/net/mlx4/mlx4_en.h

Modified: head/sys/ofed/drivers/net/mlx4/en_rx.c
==============================================================================
--- head/sys/ofed/drivers/net/mlx4/en_rx.c	Thu Apr 14 14:01:28 2016	(r297966)
+++ head/sys/ofed/drivers/net/mlx4/en_rx.c	Thu Apr 14 14:10:40 2016	(r297967)
@@ -55,7 +55,7 @@ static void mlx4_en_init_rx_desc(struct 
 	int i;
 
 	/* Set size and memtype fields */
-	rx_desc->data[0].byte_count = cpu_to_be32(priv->rx_mb_size);
+	rx_desc->data[0].byte_count = cpu_to_be32(priv->rx_mb_size - MLX4_NET_IP_ALIGN);
 	rx_desc->data[0].lkey = cpu_to_be32(priv->mdev->mr.key);
 
 	/*
@@ -87,7 +87,10 @@ mlx4_en_alloc_buf(struct mlx4_en_rx_ring
 		if (unlikely(mb == NULL))
 			return (-ENOMEM);
 		/* setup correct length */
-		mb->m_len = ring->rx_mb_size;
+		mb->m_pkthdr.len = mb->m_len = ring->rx_mb_size;
+
+		/* make sure IP header gets aligned */
+		m_adj(mb, MLX4_NET_IP_ALIGN);
 
 		/* load spare mbuf into BUSDMA */
 		err = -bus_dmamap_load_mbuf_sg(ring->dma_tag, ring->spare.dma_map,
@@ -117,7 +120,10 @@ mlx4_en_alloc_buf(struct mlx4_en_rx_ring
 		goto use_spare;
 
 	/* setup correct length */
-	mb->m_len = ring->rx_mb_size;
+	mb->m_pkthdr.len = mb->m_len = ring->rx_mb_size;
+
+	/* make sure IP header gets aligned */
+	m_adj(mb, MLX4_NET_IP_ALIGN);
 
 	err = -bus_dmamap_load_mbuf_sg(ring->dma_tag, mb_list->dma_map,
 	    mb, segs, &nsegs, BUS_DMA_NOWAIT);
@@ -249,7 +255,8 @@ static void mlx4_en_free_rx_buf(struct m
 void mlx4_en_calc_rx_buf(struct net_device *dev)
 {
 	struct mlx4_en_priv *priv = netdev_priv(dev);
-	int eff_mtu = dev->if_mtu + ETH_HLEN + VLAN_HLEN + ETH_FCS_LEN;
+	int eff_mtu = dev->if_mtu + ETH_HLEN + VLAN_HLEN + ETH_FCS_LEN +
+	    MLX4_NET_IP_ALIGN;
 
 	if (eff_mtu > MJUM16BYTES) {
 		en_err(priv, "MTU(%d) is too big\n", dev->if_mtu);

Modified: head/sys/ofed/drivers/net/mlx4/mlx4_en.h
==============================================================================
--- head/sys/ofed/drivers/net/mlx4/mlx4_en.h	Thu Apr 14 14:01:28 2016	(r297966)
+++ head/sys/ofed/drivers/net/mlx4/mlx4_en.h	Thu Apr 14 14:10:40 2016	(r297967)
@@ -69,6 +69,7 @@
 
 #define MLX4_EN_PAGE_SHIFT	12
 #define MLX4_EN_PAGE_SIZE	(1 << MLX4_EN_PAGE_SHIFT)
+#define	MLX4_NET_IP_ALIGN	2	/* bytes */
 #define DEF_RX_RINGS		16
 #define MAX_RX_RINGS		128
 #define MIN_RX_RINGS		4