qeth: rework TSO functions

The maximum TSO size OSA can handle is 15 * PAGE_SIZE. This
patch reduces gso_max_size to this value and adds some sanity
checks and statistics to the TSO implementation.
Since only layer 3 is able to do TSO move all TSO related functions
to the qeth_l3 module.

Signed-off-by: Frank Blaschka <frank.blaschka@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

7 files changed, 110 insertions, 98 deletions

diff --git a/drivers/s390/net/qeth_core.h b/drivers/s390/net/qeth_core.h
index 84c5c8f30c47..b232693378cd 100644
--- a/drivers/s390/net/qeth_core.h
+++ b/drivers/s390/net/qeth_core.h
@@ -134,6 +134,7 @@ struct qeth_perf_stats {
         unsigned int sg_frags_rx;
         unsigned int sg_alloc_page_rx;
         unsigned int tx_csum;
+        unsigned int tx_lin;
 };
 
 /* Routing stuff */
@@ -835,7 +836,6 @@ void qeth_prepare_ipa_cmd(struct qeth_card *, struct qeth_cmd_buffer *, char);
 struct qeth_cmd_buffer *qeth_wait_for_buffer(struct qeth_channel *);
 int qeth_mdio_read(struct net_device *, int, int);
 int qeth_snmp_command(struct qeth_card *, char __user *);
-int qeth_set_large_send(struct qeth_card *, enum qeth_large_send_types);
 struct qeth_cmd_buffer *qeth_get_adapter_cmd(struct qeth_card *, __u32, __u32);
 int qeth_default_setadapterparms_cb(struct qeth_card *, struct qeth_reply *,
                                         unsigned long);
diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c
index 819a3b5a647d..d34804d5ece1 100644
--- a/drivers/s390/net/qeth_core_main.c
+++ b/drivers/s390/net/qeth_core_main.c
@@ -270,41 +270,6 @@ int qeth_realloc_buffer_pool(struct qeth_card *card, int bufcnt)
         return qeth_alloc_buffer_pool(card);
 }
 
-int qeth_set_large_send(struct qeth_card *card,
-                enum qeth_large_send_types type)
-{
-        int rc = 0;
-
-        if (card->dev == NULL) {
-                card->options.large_send = type;
-                return 0;
-        }
-        if (card->state == CARD_STATE_UP)
-                netif_tx_disable(card->dev);
-        card->options.large_send = type;
-        switch (card->options.large_send) {
-        case QETH_LARGE_SEND_TSO:
-                if (qeth_is_supported(card, IPA_OUTBOUND_TSO)) {
-                        card->dev->features |= NETIF_F_TSO | NETIF_F_SG |
-                                                NETIF_F_HW_CSUM;
-                } else {
-                        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 |
-                                        NETIF_F_HW_CSUM);
-                break;
-        }
-        if (card->state == CARD_STATE_UP)
-                netif_wake_queue(card->dev);
-        return rc;
-}
-EXPORT_SYMBOL_GPL(qeth_set_large_send);
-
 static int qeth_issue_next_read(struct qeth_card *card)
 {
         int rc;
@@ -4460,6 +4425,7 @@ static struct {
         {"tx do_QDIO time"},
         {"tx do_QDIO count"},
         {"tx csum"},
+        {"tx lin"},
 };
 
 int qeth_core_get_sset_count(struct net_device *dev, int stringset)
@@ -4517,6 +4483,7 @@ void qeth_core_get_ethtool_stats(struct net_device *dev,
         data[31] = card->perf_stats.outbound_do_qdio_time;
         data[32] = card->perf_stats.outbound_do_qdio_cnt;
         data[33] = card->perf_stats.tx_csum;
+        data[34] = card->perf_stats.tx_lin;
 }
 EXPORT_SYMBOL_GPL(qeth_core_get_ethtool_stats);
 
diff --git a/drivers/s390/net/qeth_core_sys.c b/drivers/s390/net/qeth_core_sys.c
index f2358a75ed0c..9ff2b36fdc43 100644
--- a/drivers/s390/net/qeth_core_sys.c
+++ b/drivers/s390/net/qeth_core_sys.c
@@ -416,53 +416,6 @@ static ssize_t qeth_dev_layer2_store(struct device *dev,
 static DEVICE_ATTR(layer2, 0644, qeth_dev_layer2_show,
                    qeth_dev_layer2_store);
 
-static ssize_t qeth_dev_large_send_show(struct device *dev,
-                                struct device_attribute *attr, char *buf)
-{
-        struct qeth_card *card = dev_get_drvdata(dev);
-
-        if (!card)
-                return -EINVAL;
-
-        switch (card->options.large_send) {
-        case QETH_LARGE_SEND_NO:
-                return sprintf(buf, "%s\n", "no");
-        case QETH_LARGE_SEND_TSO:
-                return sprintf(buf, "%s\n", "TSO");
-        default:
-                return sprintf(buf, "%s\n", "N/A");
-        }
-}
-
-static ssize_t qeth_dev_large_send_store(struct device *dev,
-                struct device_attribute *attr, const char *buf, size_t count)
-{
-        struct qeth_card *card = dev_get_drvdata(dev);
-        enum qeth_large_send_types type;
-        int rc = 0;
-        char *tmp;
-
-        if (!card)
-                return -EINVAL;
-        tmp = strsep((char **) &buf, "\n");
-        if (!strcmp(tmp, "no")) {
-                type = QETH_LARGE_SEND_NO;
-        } else if (!strcmp(tmp, "TSO")) {
-                type = QETH_LARGE_SEND_TSO;
-        } else {
-                return -EINVAL;
-        }
-        if (card->options.large_send == type)
-                return count;
-        rc = qeth_set_large_send(card, type);
-        if (rc)
-                return rc;
-        return count;
-}
-
-static DEVICE_ATTR(large_send, 0644, qeth_dev_large_send_show,
-                   qeth_dev_large_send_store);
-
 #define ATTR_QETH_ISOLATION_NONE        ("none")
 #define ATTR_QETH_ISOLATION_FWD         ("forward")
 #define ATTR_QETH_ISOLATION_DROP        ("drop")
@@ -658,7 +611,6 @@ static struct attribute *qeth_device_attrs[] = {
         &dev_attr_recover.attr,
         &dev_attr_performance_stats.attr,
         &dev_attr_layer2.attr,
-        &dev_attr_large_send.attr,
         &dev_attr_isolation.attr,
         NULL,
 };
diff --git a/drivers/s390/net/qeth_l2_main.c b/drivers/s390/net/qeth_l2_main.c
index 372f2c0cd547..0b763396d5d1 100644
--- a/drivers/s390/net/qeth_l2_main.c
+++ b/drivers/s390/net/qeth_l2_main.c
@@ -978,7 +978,6 @@ static int __qeth_l2_set_online(struct ccwgroup_device *gdev, int recovery_mode)
         if (card->info.type != QETH_CARD_TYPE_OSN) {
                 /* configure isolation level */
                 qeth_set_access_ctrl_online(card);
-                qeth_set_large_send(card, card->options.large_send);
                 qeth_l2_process_vlans(card, 0);
         }
 
diff --git a/drivers/s390/net/qeth_l3.h b/drivers/s390/net/qeth_l3.h
index 9f143c83bba3..ffa6fe4da26a 100644
--- a/drivers/s390/net/qeth_l3.h
+++ b/drivers/s390/net/qeth_l3.h
@@ -60,5 +60,6 @@ void qeth_l3_del_vipa(struct qeth_card *, enum qeth_prot_versions, const u8 *);
 int qeth_l3_add_rxip(struct qeth_card *, enum qeth_prot_versions, const u8 *);
 void qeth_l3_del_rxip(struct qeth_card *card, enum qeth_prot_versions,
                         const u8 *);
+int qeth_l3_set_large_send(struct qeth_card *, enum qeth_large_send_types);
 
 #endif /* __QETH_L3_H__ */
diff --git a/drivers/s390/net/qeth_l3_main.c b/drivers/s390/net/qeth_l3_main.c
index 03f67bb51e99..2048b4354216 100644
--- a/drivers/s390/net/qeth_l3_main.c
+++ b/drivers/s390/net/qeth_l3_main.c
@@ -41,6 +41,32 @@ static int qeth_l3_deregister_addr_entry(struct qeth_card *,
 static int __qeth_l3_set_online(struct ccwgroup_device *, int);
 static int __qeth_l3_set_offline(struct ccwgroup_device *, int);
 
+int qeth_l3_set_large_send(struct qeth_card *card,
+                enum qeth_large_send_types type)
+{
+        int rc = 0;
+
+        card->options.large_send = type;
+        if (card->dev == NULL)
+                return 0;
+
+        if (card->options.large_send == QETH_LARGE_SEND_TSO) {
+                if (qeth_is_supported(card, IPA_OUTBOUND_TSO)) {
+                        card->dev->features |= NETIF_F_TSO | NETIF_F_SG |
+                                        NETIF_F_HW_CSUM;
+                } else {
+                        card->dev->features &= ~(NETIF_F_TSO | NETIF_F_SG |
+                                        NETIF_F_HW_CSUM);
+                        card->options.large_send = QETH_LARGE_SEND_NO;
+                        rc = -EOPNOTSUPP;
+                }
+        } else {
+                card->dev->features &= ~(NETIF_F_TSO | NETIF_F_SG |
+                                        NETIF_F_HW_CSUM);
+                card->options.large_send = QETH_LARGE_SEND_NO;
+        }
+        return rc;
+}
 
 static int qeth_l3_isxdigit(char *buf)
 {
@@ -2686,6 +2712,24 @@ static void qeth_tx_csum(struct sk_buff *skb)
         *(__sum16 *)(skb->data + offset) = csum_fold(csum);
 }
 
+static inline int qeth_l3_tso_elements(struct sk_buff *skb)
+{
+        unsigned long tcpd = (unsigned long)tcp_hdr(skb) +
+                tcp_hdr(skb)->doff * 4;
+        int tcpd_len = skb->len - (tcpd - (unsigned long)skb->data);
+        int elements = PFN_UP(tcpd + tcpd_len) - PFN_DOWN(tcpd);
+        elements += skb_shinfo(skb)->nr_frags;
+        return elements;
+}
+
+static inline int qeth_l3_tso_check(struct sk_buff *skb)
+{
+        int len = ((unsigned long)tcp_hdr(skb) + tcp_hdr(skb)->doff * 4) -
+                (unsigned long)skb->data;
+        return (((unsigned long)skb->data & PAGE_MASK) !=
+                (((unsigned long)skb->data + len) & PAGE_MASK));
+}
+
 static int qeth_l3_hard_start_xmit(struct sk_buff *skb, struct net_device *dev)
 {
         int rc;
@@ -2779,16 +2823,21 @@ static int qeth_l3_hard_start_xmit(struct sk_buff *skb, struct net_device *dev)
         /* fix hardware limitation: as long as we do not have sbal
          * chaining we can not send long frag lists
          */
-        if ((large_send == QETH_LARGE_SEND_TSO) &&
-            ((skb_shinfo(new_skb)->nr_frags + 2) > 16)) {
-                if (skb_linearize(new_skb))
-                        goto tx_drop;
+        if (large_send == QETH_LARGE_SEND_TSO) {
+                if (qeth_l3_tso_elements(new_skb) + 1 > 16) {
+                        if (skb_linearize(new_skb))
+                                goto tx_drop;
+                        if (card->options.performance_stats)
+                                card->perf_stats.tx_lin++;
+                }
         }
 
         if ((large_send == QETH_LARGE_SEND_TSO) &&
             (cast_type == RTN_UNSPEC)) {
                 hdr = (struct qeth_hdr *)skb_push(new_skb,
                                                 sizeof(struct qeth_hdr_tso));
+                if (qeth_l3_tso_check(new_skb))
+                        QETH_DBF_MESSAGE(2, "tso skb misaligned\n");
                 memset(hdr, 0, sizeof(struct qeth_hdr_tso));
                 qeth_l3_fill_header(card, hdr, new_skb, ipv, cast_type);
                 qeth_tso_fill_header(card, hdr, new_skb);
@@ -2931,20 +2980,15 @@ static int qeth_l3_ethtool_set_rx_csum(struct net_device *dev, u32 data)
 static int qeth_l3_ethtool_set_tso(struct net_device *dev, u32 data)
 {
         struct qeth_card *card = dev->ml_priv;
+        int rc = 0;
 
         if (data) {
-                if (card->options.large_send == QETH_LARGE_SEND_NO) {
-                        if (card->info.type == QETH_CARD_TYPE_IQD)
-                                return -EPERM;
-                        else
-                                card->options.large_send = QETH_LARGE_SEND_TSO;
-                        dev->features |= NETIF_F_TSO;
-                }
+                rc = qeth_l3_set_large_send(card, QETH_LARGE_SEND_TSO);
         } else {
                 dev->features &= ~NETIF_F_TSO;
                 card->options.large_send = QETH_LARGE_SEND_NO;
         }
-        return 0;
+        return rc;
 }
 
 static const struct ethtool_ops qeth_l3_ethtool_ops = {
@@ -3060,6 +3104,7 @@ static int qeth_l3_setup_netdev(struct qeth_card *card)
                                 NETIF_F_HW_VLAN_RX |
                                 NETIF_F_HW_VLAN_FILTER;
         card->dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
+        card->dev->gso_max_size = 15 * PAGE_SIZE;
 
         SET_NETDEV_DEV(card->dev, &card->gdev->dev);
         return register_netdev(card->dev);
@@ -3189,7 +3234,7 @@ static int __qeth_l3_set_online(struct ccwgroup_device *gdev, int recovery_mode)
                 goto out_remove;
         } else
                 card->lan_online = 1;
-        qeth_set_large_send(card, card->options.large_send);
+        qeth_l3_set_large_send(card, card->options.large_send);
 
         rc = qeth_l3_setadapter_parms(card);
         if (rc)
diff --git a/drivers/s390/net/qeth_l3_sys.c b/drivers/s390/net/qeth_l3_sys.c
index c144b9924d52..88f200c8ea3c 100644
--- a/drivers/s390/net/qeth_l3_sys.c
+++ b/drivers/s390/net/qeth_l3_sys.c
@@ -318,6 +318,53 @@ static ssize_t qeth_l3_dev_checksum_store(struct device *dev,
 static DEVICE_ATTR(checksumming, 0644, qeth_l3_dev_checksum_show,
                 qeth_l3_dev_checksum_store);
 
+static ssize_t qeth_l3_dev_large_send_show(struct device *dev,
+                                struct device_attribute *attr, char *buf)
+{
+        struct qeth_card *card = dev_get_drvdata(dev);
+
+        if (!card)
+                return -EINVAL;
+
+        switch (card->options.large_send) {
+        case QETH_LARGE_SEND_NO:
+                return sprintf(buf, "%s\n", "no");
+        case QETH_LARGE_SEND_TSO:
+                return sprintf(buf, "%s\n", "TSO");
+        default:
+                return sprintf(buf, "%s\n", "N/A");
+        }
+}
+
+static ssize_t qeth_l3_dev_large_send_store(struct device *dev,
+                struct device_attribute *attr, const char *buf, size_t count)
+{
+        struct qeth_card *card = dev_get_drvdata(dev);
+        enum qeth_large_send_types type;
+        int rc = 0;
+        char *tmp;
+
+        if (!card)
+                return -EINVAL;
+        tmp = strsep((char **) &buf, "\n");
+        if (!strcmp(tmp, "no"))
+                type = QETH_LARGE_SEND_NO;
+        else if (!strcmp(tmp, "TSO"))
+                type = QETH_LARGE_SEND_TSO;
+        else
+                return -EINVAL;
+
+        if (card->options.large_send == type)
+                return count;
+        rc = qeth_l3_set_large_send(card, type);
+        if (rc)
+                return rc;
+        return count;
+}
+
+static DEVICE_ATTR(large_send, 0644, qeth_l3_dev_large_send_show,
+                   qeth_l3_dev_large_send_store);
+
 static struct attribute *qeth_l3_device_attrs[] = {
         &dev_attr_route4.attr,
         &dev_attr_route6.attr,
@@ -325,6 +372,7 @@ static struct attribute *qeth_l3_device_attrs[] = {
         &dev_attr_broadcast_mode.attr,
         &dev_attr_canonical_macaddr.attr,
         &dev_attr_checksumming.attr,
+        &dev_attr_large_send.attr,
         NULL,
 };