ehea: Simplify ehea_xmit2 and ehea_xmit3

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>

1 files changed, 36 insertions, 101 deletions

diff --git a/drivers/net/ethernet/ibm/ehea/ehea_main.c b/drivers/net/ethernet/ibm/ehea/ehea_main.c
index 13218092769c..77aafba8272c 100644
--- a/drivers/net/ethernet/ibm/ehea/ehea_main.c
+++ b/drivers/net/ethernet/ibm/ehea/ehea_main.c
@@ -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)
 {
@@ -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);
 }
@@ -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);
@@ -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);
 }
@@ -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