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mv643xx_eth: enable hardware TX checksumming with vlan tags

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Although mv643xx_eth has no hardware support for inserting a vlan
tag by twiddling some bits in the TX descriptor, it does support
hardware TX checksumming on packets where the IP header starts {a
limited set of values other than 14} bytes into the packet.

This patch sets mv643xx_eth's ->vlan_features to NETIF_F_SG |
NETIF_F_IP_CSUM, which prevents the stack from checksumming vlan'ed
packets in software, and if vlan tags are present on a transmitted
packet, notifies the hardware of this fact by toggling the right
bits in the TX descriptor.

Signed-off-by: Lennert Buytenhek <buytenh@marvell.com>
This commit is contained in:
Lennert Buytenhek 2008-07-24 06:22:59 +02:00 committed by Lennert Buytenhek
parent 2f7eb47a7b
commit e32b661750
1 changed files with 28 additions and 1 deletions
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29
drivers/net/mv643xx_eth.c
View file

@ -235,6 +235,8 @@ struct tx_desc {
#define GEN_IP_V4_CHECKSUM 0x00040000
#define GEN_TCP_UDP_CHECKSUM 0x00020000
#define UDP_FRAME 0x00010000
#define MAC_HDR_EXTRA_4_BYTES 0x00008000
#define MAC_HDR_EXTRA_8_BYTES 0x00000200
#define TX_IHL_SHIFT 11
@ -757,12 +759,36 @@ static void txq_submit_skb(struct tx_queue *txq, struct sk_buff *skb)
desc->buf_ptr = dma_map_single(NULL, skb->data, length, DMA_TO_DEVICE);
if (skb->ip_summed == CHECKSUM_PARTIAL) {
BUG_ON(skb->protocol != htons(ETH_P_IP));
int mac_hdr_len;
BUG_ON(skb->protocol != htons(ETH_P_IP) &&
skb->protocol != htons(ETH_P_8021Q));
cmd_sts |= GEN_TCP_UDP_CHECKSUM |
GEN_IP_V4_CHECKSUM |
ip_hdr(skb)->ihl << TX_IHL_SHIFT;
mac_hdr_len = (void *)ip_hdr(skb) - (void *)skb->data;
switch (mac_hdr_len - ETH_HLEN) {
case 0:
break;
case 4:
cmd_sts |= MAC_HDR_EXTRA_4_BYTES;
break;
case 8:
cmd_sts |= MAC_HDR_EXTRA_8_BYTES;
break;
case 12:
cmd_sts |= MAC_HDR_EXTRA_4_BYTES;
cmd_sts |= MAC_HDR_EXTRA_8_BYTES;
break;
default:
if (net_ratelimit())
dev_printk(KERN_ERR, &txq_to_mp(txq)->dev->dev,
"mac header length is %d?!\n", mac_hdr_len);
break;
}
switch (ip_hdr(skb)->protocol) {
case IPPROTO_UDP:
cmd_sts |= UDP_FRAME;
@ -2565,6 +2591,7 @@ static int mv643xx_eth_probe(struct platform_device *pdev)
* have to map the buffers to ISA memory which is only 16 MB
*/
dev->features = NETIF_F_SG | NETIF_F_IP_CSUM;
dev->vlan_features = NETIF_F_SG | NETIF_F_IP_CSUM;
#endif
SET_NETDEV_DEV(dev, &pdev->dev);