qeth: Announce tx checksumming for qeth devices in TSO/EDDP mode

TSO requires tx checksumming. For non GSO frames in TSO/EDDP mode we
have to manually calculate the checksum.

Signed-off-by: Frank Blaschka <frank.blaschka@de.ibm.com>
Signed-off-by: Ursula Braun <braunu@de.ibm.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

1 files changed, 68 insertions, 14 deletions

diff --git a/drivers/s390/net/qeth_main.c b/drivers/s390/net/qeth_main.c
index 610d27cfd28b..443cde10353e 100644
--- a/drivers/s390/net/qeth_main.c
+++ b/drivers/s390/net/qeth_main.c
@@ -4555,6 +4555,53 @@ qeth_get_elements_no(struct qeth_card *card, void *hdr,
         return elements_needed;
 }
 
+static void qeth_tx_csum(struct sk_buff *skb)
+{
+        int tlen;
+
+        if (skb->protocol == htons(ETH_P_IP)) {
+                tlen = ntohs(ip_hdr(skb)->tot_len) - (ip_hdr(skb)->ihl << 2);
+                switch (ip_hdr(skb)->protocol) {
+                case IPPROTO_TCP:
+                        tcp_hdr(skb)->check = 0;
+                        tcp_hdr(skb)->check = csum_tcpudp_magic(
+                                ip_hdr(skb)->saddr, ip_hdr(skb)->daddr,
+                                tlen, ip_hdr(skb)->protocol,
+                                skb_checksum(skb, skb_transport_offset(skb),
+                                        tlen, 0));
+                        break;
+                case IPPROTO_UDP:
+                        udp_hdr(skb)->check = 0;
+                        udp_hdr(skb)->check = csum_tcpudp_magic(
+                                ip_hdr(skb)->saddr, ip_hdr(skb)->daddr,
+                                tlen, ip_hdr(skb)->protocol,
+                                skb_checksum(skb, skb_transport_offset(skb),
+                                        tlen, 0));
+                        break;
+                }
+        } else if (skb->protocol == htons(ETH_P_IPV6)) {
+                switch (ipv6_hdr(skb)->nexthdr) {
+                case IPPROTO_TCP:
+                        tcp_hdr(skb)->check = 0;
+                        tcp_hdr(skb)->check = csum_ipv6_magic(
+                                &ipv6_hdr(skb)->saddr, &ipv6_hdr(skb)->daddr,
+                                ipv6_hdr(skb)->payload_len,
+                                ipv6_hdr(skb)->nexthdr,
+                                skb_checksum(skb, skb_transport_offset(skb),
+                                        ipv6_hdr(skb)->payload_len, 0));
+                        break;
+                case IPPROTO_UDP:
+                        udp_hdr(skb)->check = 0;
+                        udp_hdr(skb)->check = csum_ipv6_magic(
+                                &ipv6_hdr(skb)->saddr, &ipv6_hdr(skb)->daddr,
+                                ipv6_hdr(skb)->payload_len,
+                                ipv6_hdr(skb)->nexthdr,
+                                skb_checksum(skb, skb_transport_offset(skb),
+                                        ipv6_hdr(skb)->payload_len, 0));
+                        break;
+                }
+        }
+}
 
 static int
 qeth_send_packet(struct qeth_card *card, struct sk_buff *skb)
@@ -4640,6 +4687,10 @@ qeth_send_packet(struct qeth_card *card, struct sk_buff *skb)
                 elements_needed += elems;
         }
 
+        if ((large_send == QETH_LARGE_SEND_NO) &&
+            (skb->ip_summed == CHECKSUM_PARTIAL))
+                qeth_tx_csum(new_skb);
+
         if (card->info.type != QETH_CARD_TYPE_IQD)
                 rc = qeth_do_send_packet(card, queue, new_skb, hdr,
                                          elements_needed, ctx);
@@ -6387,20 +6438,18 @@ qeth_deregister_addr_entry(struct qeth_card *card, struct qeth_ipaddr *addr)
 static u32
 qeth_ethtool_get_tx_csum(struct net_device *dev)
 {
-        /* We may need to say that we support tx csum offload if
-         * we do EDDP or TSO. There are discussions going on to
-         * enforce rules in the stack and in ethtool that make
-         * SG and TSO depend on HW_CSUM. At the moment there are
-         * no such rules....
-         * If we say yes here, we have to checksum outbound packets
-         * any time. */
-        return 0;
+        return (dev->features & NETIF_F_HW_CSUM) != 0;
 }
 
 static int
 qeth_ethtool_set_tx_csum(struct net_device *dev, u32 data)
 {
-        return -EINVAL;
+        if (data)
+                dev->features |= NETIF_F_HW_CSUM;
+        else
+                dev->features &= ~NETIF_F_HW_CSUM;
+
+        return 0;
 }
 
 static u32
@@ -7414,7 +7463,8 @@ qeth_start_ipa_tso(struct qeth_card *card)
         }
         if (rc && (card->options.large_send == QETH_LARGE_SEND_TSO)){
                 card->options.large_send = QETH_LARGE_SEND_NO;
-                card->dev->features &= ~ (NETIF_F_TSO | NETIF_F_SG);
+                card->dev->features &= ~(NETIF_F_TSO | NETIF_F_SG |
+                                                NETIF_F_HW_CSUM);
         }
         return rc;
 }
@@ -7554,22 +7604,26 @@ qeth_set_large_send(struct qeth_card *card, enum qeth_large_send_types type)
         card->options.large_send = type;
         switch (card->options.large_send) {
         case QETH_LARGE_SEND_EDDP:
-                card->dev->features |= NETIF_F_TSO | NETIF_F_SG;
+                card->dev->features |= NETIF_F_TSO | NETIF_F_SG |
+                                        NETIF_F_HW_CSUM;
                 break;
         case QETH_LARGE_SEND_TSO:
                 if (qeth_is_supported(card, IPA_OUTBOUND_TSO)){
-                        card->dev->features |= NETIF_F_TSO | NETIF_F_SG;
+                        card->dev->features |= NETIF_F_TSO | NETIF_F_SG |
+                                                NETIF_F_HW_CSUM;
                 } else {
                         PRINT_WARN("TSO not supported on %s. "
                                    "large_send set to 'no'.\n",
                                    card->dev->name);
-                        card->dev->features &= ~(NETIF_F_TSO | NETIF_F_SG);
+                        card->dev->features &= ~(NETIF_F_TSO | NETIF_F_SG |
+                                                NETIF_F_HW_CSUM);
                         card->options.large_send = QETH_LARGE_SEND_NO;
                         rc = -EOPNOTSUPP;
                 }
                 break;
         default: /* includes QETH_LARGE_SEND_NO */
-                card->dev->features &= ~(NETIF_F_TSO | NETIF_F_SG);
+                card->dev->features &= ~(NETIF_F_TSO | NETIF_F_SG |
+                                        NETIF_F_HW_CSUM);
                 break;
         }
         if (card->state == CARD_STATE_UP)