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net: fec: fix regression on i.MX28 introduced by rx_copybreak support

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commit 1b7bde6d65 ("net: fec: implement rx_copybreak to improve rx performance")
introduced a regression for i.MX28. The swap_buffer() function doing
the endian conversion of the received data on i.MX28 may access memory
beyond the actual packet size in the DMA buffer. fec_enet_copybreak()
does not copy those bytes, so that the last bytes of a packet may be
filled with invalid data after swapping.
This will likely lead to checksum errors on received packets.
E.g. when trying to mount an NFS rootfs:
UDP: bad checksum. From 192.168.1.225:111 to 192.168.100.73:44662 ulen 36

Do the byte swapping and copying to the new skb in one go if
necessary.

Signed-off-by: Lothar Waßmann <LW@KARO-electronics.de>
Tested-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Lothar Waßmann 2014-11-07 10:02:47 +01:00 committed by David S. Miller
parent 1f5623106f
commit 1310b544e5
1 changed files with 19 additions and 4 deletions
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23
drivers/net/ethernet/freescale/fec_main.c
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@ -298,6 +298,16 @@ static void *swap_buffer(void *bufaddr, int len)
return bufaddr;
}
static void swap_buffer2(void *dst_buf, void *src_buf, int len)
{
int i;
unsigned int *src = src_buf;
unsigned int *dst = dst_buf;
for (i = 0; i < len; i += 4, src++, dst++)
*dst = swab32p(src);
}
static void fec_dump(struct net_device *ndev)
{
struct fec_enet_private *fep = netdev_priv(ndev);
@ -1307,7 +1317,7 @@ fec_enet_new_rxbdp(struct net_device *ndev, struct bufdesc *bdp, struct sk_buff
}
static bool fec_enet_copybreak(struct net_device *ndev, struct sk_buff **skb,
struct bufdesc *bdp, u32 length)
struct bufdesc *bdp, u32 length, bool swap)
{
struct fec_enet_private *fep = netdev_priv(ndev);
struct sk_buff *new_skb;
@ -1322,7 +1332,10 @@ static bool fec_enet_copybreak(struct net_device *ndev, struct sk_buff **skb,
dma_sync_single_for_cpu(&fep->pdev->dev, bdp->cbd_bufaddr,
FEC_ENET_RX_FRSIZE - fep->rx_align,
DMA_FROM_DEVICE);
memcpy(new_skb->data, (*skb)->data, length);
if (!swap)
memcpy(new_skb->data, (*skb)->data, length);
else
swap_buffer2(new_skb->data, (*skb)->data, length);
*skb = new_skb;
return true;
@ -1352,6 +1365,7 @@ fec_enet_rx_queue(struct net_device *ndev, int budget, u16 queue_id)
u16 vlan_tag;
int index = 0;
bool is_copybreak;
bool need_swap = id_entry->driver_data & FEC_QUIRK_SWAP_FRAME;
#ifdef CONFIG_M532x
flush_cache_all();
@ -1415,7 +1429,8 @@ fec_enet_rx_queue(struct net_device *ndev, int budget, u16 queue_id)
* include that when passing upstream as it messes up
* bridging applications.
*/
is_copybreak = fec_enet_copybreak(ndev, &skb, bdp, pkt_len - 4);
is_copybreak = fec_enet_copybreak(ndev, &skb, bdp, pkt_len - 4,
need_swap);
if (!is_copybreak) {
skb_new = netdev_alloc_skb(ndev, FEC_ENET_RX_FRSIZE);
if (unlikely(!skb_new)) {
@ -1430,7 +1445,7 @@ fec_enet_rx_queue(struct net_device *ndev, int budget, u16 queue_id)
prefetch(skb->data - NET_IP_ALIGN);
skb_put(skb, pkt_len - 4);
data = skb->data;
if (id_entry->driver_data & FEC_QUIRK_SWAP_FRAME)
if (!is_copybreak && need_swap)
swap_buffer(data, pkt_len);
/* Extract the enhanced buffer descriptor */