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ehea: Simplify ehea_xmit2 and ehea_xmit3
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Based on a patch from Michael Ellerman, clean up a significant
portion of the transmit path. There was a lot of duplication here.
Even worse, we were always checksumming tx packets and ignoring the
skb->ip_summed field.

Also remove NETIF_F_FRAGLIST from dev->features, I'm not sure why
it was enabled.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Anton Blanchard authored and David S. Miller committed Oct 17, 2011
1 parent 945db2d commit d695c33
Showing 1 changed file with 36 additions and 101 deletions.
137 changes: 36 additions & 101 deletions drivers/net/ethernet/ibm/ehea/ehea_main.c
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Original file line number Diff line number Diff line change
Expand Up @@ -1676,37 +1676,6 @@ static int ehea_clean_portres(struct ehea_port *port, struct ehea_port_res *pr)
return ret;
}

/*
* The write_* functions store information in swqe which is used by
* the hardware to calculate the ip/tcp/udp checksum
*/

static inline void write_ip_start_end(struct ehea_swqe *swqe,
const struct sk_buff *skb)
{
swqe->ip_start = skb_network_offset(skb);
swqe->ip_end = (u8)(swqe->ip_start + ip_hdrlen(skb) - 1);
}

static inline void write_tcp_offset_end(struct ehea_swqe *swqe,
const struct sk_buff *skb)
{
swqe->tcp_offset =
(u8)(swqe->ip_end + 1 + offsetof(struct tcphdr, check));

swqe->tcp_end = (u16)skb->len - 1;
}

static inline void write_udp_offset_end(struct ehea_swqe *swqe,
const struct sk_buff *skb)
{
swqe->tcp_offset =
(u8)(swqe->ip_end + 1 + offsetof(struct udphdr, check));

swqe->tcp_end = (u16)skb->len - 1;
}


static void write_swqe2_TSO(struct sk_buff *skb,
struct ehea_swqe *swqe, u32 lkey)
{
Expand Down Expand Up @@ -2105,41 +2074,46 @@ static int ehea_change_mtu(struct net_device *dev, int new_mtu)
return 0;
}

static void ehea_xmit2(struct sk_buff *skb, struct net_device *dev,
struct ehea_swqe *swqe, u32 lkey)
static void xmit_common(struct sk_buff *skb, struct ehea_swqe *swqe)
{
if (skb->protocol == htons(ETH_P_IP)) {
const struct iphdr *iph = ip_hdr(skb);
swqe->tx_control |= EHEA_SWQE_IMM_DATA_PRESENT | EHEA_SWQE_CRC;

/* IPv4 */
swqe->tx_control |= EHEA_SWQE_CRC
| EHEA_SWQE_IP_CHECKSUM
| EHEA_SWQE_TCP_CHECKSUM
| EHEA_SWQE_IMM_DATA_PRESENT
| EHEA_SWQE_DESCRIPTORS_PRESENT;
if (skb->protocol != htons(ETH_P_IP))
return;

write_ip_start_end(swqe, skb);
if (skb->ip_summed == CHECKSUM_PARTIAL)
swqe->tx_control |= EHEA_SWQE_IP_CHECKSUM;

if (iph->protocol == IPPROTO_UDP) {
if ((iph->frag_off & IP_MF) ||
(iph->frag_off & IP_OFFSET))
/* IP fragment, so don't change cs */
swqe->tx_control &= ~EHEA_SWQE_TCP_CHECKSUM;
else
write_udp_offset_end(swqe, skb);
} else if (iph->protocol == IPPROTO_TCP) {
write_tcp_offset_end(swqe, skb);
}
swqe->ip_start = skb_network_offset(skb);
swqe->ip_end = swqe->ip_start + ip_hdrlen(skb) - 1;

/* icmp (big data) and ip segmentation packets (all other ip
packets) do not require any special handling */
switch (ip_hdr(skb)->protocol) {
case IPPROTO_UDP:
if (skb->ip_summed == CHECKSUM_PARTIAL)
swqe->tx_control |= EHEA_SWQE_TCP_CHECKSUM;

} else {
/* Other Ethernet Protocol */
swqe->tx_control |= EHEA_SWQE_CRC
| EHEA_SWQE_IMM_DATA_PRESENT
| EHEA_SWQE_DESCRIPTORS_PRESENT;
swqe->tcp_offset = swqe->ip_end + 1 +
offsetof(struct udphdr, check);
swqe->tcp_end = skb->len - 1;
break;

case IPPROTO_TCP:
if (skb->ip_summed == CHECKSUM_PARTIAL)
swqe->tx_control |= EHEA_SWQE_TCP_CHECKSUM;

swqe->tcp_offset = swqe->ip_end + 1 +
offsetof(struct tcphdr, check);
swqe->tcp_end = skb->len - 1;
break;
}
}

static void ehea_xmit2(struct sk_buff *skb, struct net_device *dev,
struct ehea_swqe *swqe, u32 lkey)
{
swqe->tx_control |= EHEA_SWQE_DESCRIPTORS_PRESENT;

xmit_common(skb, swqe);

write_swqe2_data(skb, dev, swqe, lkey);
}
Expand All @@ -2152,51 +2126,11 @@ static void ehea_xmit3(struct sk_buff *skb, struct net_device *dev,
skb_frag_t *frag;
int i;

if (skb->protocol == htons(ETH_P_IP)) {
const struct iphdr *iph = ip_hdr(skb);
xmit_common(skb, swqe);

/* IPv4 */
write_ip_start_end(swqe, skb);

if (iph->protocol == IPPROTO_TCP) {
swqe->tx_control |= EHEA_SWQE_CRC
| EHEA_SWQE_IP_CHECKSUM
| EHEA_SWQE_TCP_CHECKSUM
| EHEA_SWQE_IMM_DATA_PRESENT;

write_tcp_offset_end(swqe, skb);

} else if (iph->protocol == IPPROTO_UDP) {
if ((iph->frag_off & IP_MF) ||
(iph->frag_off & IP_OFFSET))
/* IP fragment, so don't change cs */
swqe->tx_control |= EHEA_SWQE_CRC
| EHEA_SWQE_IMM_DATA_PRESENT;
else {
swqe->tx_control |= EHEA_SWQE_CRC
| EHEA_SWQE_IP_CHECKSUM
| EHEA_SWQE_TCP_CHECKSUM
| EHEA_SWQE_IMM_DATA_PRESENT;

write_udp_offset_end(swqe, skb);
}
} else {
/* icmp (big data) and
ip segmentation packets (all other ip packets) */
swqe->tx_control |= EHEA_SWQE_CRC
| EHEA_SWQE_IP_CHECKSUM
| EHEA_SWQE_IMM_DATA_PRESENT;
}
} else {
/* Other Ethernet Protocol */
swqe->tx_control |= EHEA_SWQE_CRC | EHEA_SWQE_IMM_DATA_PRESENT;
}
/* copy (immediate) data */
if (nfrags == 0) {
/* data is in a single piece */
skb_copy_from_linear_data(skb, imm_data, skb->len);
} else {
/* first copy data from the skb->data buffer ... */
skb_copy_from_linear_data(skb, imm_data,
skb_headlen(skb));
imm_data += skb_headlen(skb);
Expand All @@ -2208,6 +2142,7 @@ static void ehea_xmit3(struct sk_buff *skb, struct net_device *dev,
imm_data += frag->size;
}
}

swqe->immediate_data_length = skb->len;
dev_kfree_skb(skb);
}
Expand Down Expand Up @@ -3184,7 +3119,7 @@ struct ehea_port *ehea_setup_single_port(struct ehea_adapter *adapter,
dev->netdev_ops = &ehea_netdev_ops;
ehea_set_ethtool_ops(dev);

dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_TSO
dev->hw_features = NETIF_F_SG | NETIF_F_TSO
| NETIF_F_IP_CSUM | NETIF_F_HW_VLAN_TX | NETIF_F_LRO;
dev->features = NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_TSO
| NETIF_F_HIGHDMA | NETIF_F_IP_CSUM | NETIF_F_HW_VLAN_TX
Expand Down

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