qeth: clean up condition when tso is used

Make conditions under which TSO is activated more stringent.
Make calculation of SBALEs required for the skb more accurate.

Signed-off-by: Eugene Crosser <Eugene.Crosser@ru.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/s390/net/qeth_core.h b/drivers/s390/net/qeth_core.h
index eb8f434a2681c73ab9bd908e2b6691416895f466..c3ab956536ff4eba80f77fdf4d58f97356a09f18 100644 (file)
--- a/drivers/s390/net/qeth_core.h
+++ b/drivers/s390/net/qeth_core.h
@@ -19,6 +19,7 @@
 #include <linux/seq_file.h>
 #include <linux/ethtool.h>
 #include <linux/hashtable.h>
+#include <linux/ip.h>
 
 #include <net/ipv6.h>
 #include <net/if_inet6.h>
@@ -878,6 +879,11 @@ static inline int qeth_get_ip_version(struct sk_buff *skb)
        }
 }
 
+static inline int qeth_get_ip_protocol(struct sk_buff *skb)
+{
+       return ip_hdr(skb)->protocol;
+}
+
 static inline void qeth_put_buffer_pool_entry(struct qeth_card *card,
                struct qeth_buffer_pool_entry *entry)
 {

diff --git a/drivers/s390/net/qeth_l3_main.c b/drivers/s390/net/qeth_l3_main.c
index 7c9968adb66d4a9fd5b28d931bbfcfbf87150514..86b3bc28d9d49e08a093a8a3b56166ae3c8fb87f 100644 (file)
--- a/drivers/s390/net/qeth_l3_main.c
+++ b/drivers/s390/net/qeth_l3_main.c
@@ -2794,10 +2794,10 @@ static void qeth_tso_fill_header(struct qeth_card *card,
 }
 
 /**
- * qeth_get_elements_no_tso() - find number of SBALEs for skb data, inc. frags.
- * @card:                      qeth card structure, to check max. elems.
- * @skb:                       SKB address
- * @extra_elems:               extra elems needed, to check against max.
+ * qeth_l3_get_elements_no_tso() - find number of SBALEs for skb data for tso
+ * @card:                         qeth card structure, to check max. elems.
+ * @skb:                          SKB address
+ * @extra_elems:                  extra elems needed, to check against max.
  *
  * Returns the number of pages, and thus QDIO buffer elements, needed to cover
  * skb data, including linear part and fragments, but excluding TCP header.
@@ -2806,7 +2806,7 @@ static void qeth_tso_fill_header(struct qeth_card *card,
  * Returns 0 if it does not.
  * Note: extra_elems is not included in the returned result.
  */
-static int qeth_get_elements_no_tso(struct qeth_card *card,
+static int qeth_l3_get_elements_no_tso(struct qeth_card *card,
                        struct sk_buff *skb, int extra_elems)
 {
        addr_t tcpdptr = (addr_t)tcp_hdr(skb) + tcp_hdrlen(skb);
@@ -2841,7 +2841,7 @@ static int qeth_l3_hard_start_xmit(struct sk_buff *skb, struct net_device *dev)
                        qeth_get_priority_queue(card, skb, ipv, cast_type) :
                        card->qdio.default_out_queue];
        int tx_bytes = skb->len;
-       bool large_send;
+       bool use_tso;
        int data_offset = -1;
        int nr_frags;
 
@@ -2866,10 +2866,12 @@ static int qeth_l3_hard_start_xmit(struct sk_buff *skb, struct net_device *dev)
                card->perf_stats.outbound_start_time = qeth_get_micros();
        }
 
-       large_send = skb_is_gso(skb);
+       /* Ignore segment size from skb_is_gso(), 1 page is always used. */
+       use_tso = skb_is_gso(skb) &&
+                 (qeth_get_ip_protocol(skb) == IPPROTO_TCP) && (ipv == 4);
 
-       if ((card->info.type == QETH_CARD_TYPE_IQD) && (!large_send) &&
-           (skb_shinfo(skb)->nr_frags == 0)) {
+       if ((card->info.type == QETH_CARD_TYPE_IQD) &&
+           !skb_is_nonlinear(skb)) {
                new_skb = skb;
                if (new_skb->protocol == ETH_P_AF_IUCV)
                        data_offset = 0;
@@ -2913,16 +2915,16 @@ 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) {
-               if (!qeth_get_elements_no_tso(card, new_skb, 1)) {
-                       if (skb_linearize(new_skb))
-                               goto tx_drop;
-                       if (card->options.performance_stats)
-                               card->perf_stats.tx_lin++;
-               }
+       if ((card->info.type != QETH_CARD_TYPE_IQD) &&
+           ((use_tso && !qeth_l3_get_elements_no_tso(card, new_skb, 1)) ||
+            (!use_tso && !qeth_get_elements_no(card, new_skb, 0)))) {
+               if (skb_linearize(new_skb))
+                       goto tx_drop;
+               if (card->options.performance_stats)
+                       card->perf_stats.tx_lin++;
        }
 
-       if (large_send && (cast_type == RTN_UNSPEC)) {
+       if (use_tso) {
                hdr = (struct qeth_hdr *)skb_push(new_skb,
                                                sizeof(struct qeth_hdr_tso));
                memset(hdr, 0, sizeof(struct qeth_hdr_tso));
@@ -2949,7 +2951,9 @@ static int qeth_l3_hard_start_xmit(struct sk_buff *skb, struct net_device *dev)
                        qeth_l3_hdr_csum(card, hdr, new_skb);
        }
 
-       elements = qeth_get_elements_no(card, new_skb, hdr_elements);
+       elements = use_tso ?
+                  qeth_l3_get_elements_no_tso(card, new_skb, hdr_elements) :
+                  qeth_get_elements_no(card, new_skb, hdr_elements);
        if (!elements) {
                if (data_offset >= 0)
                        kmem_cache_free(qeth_core_header_cache, hdr);
@@ -2959,7 +2963,7 @@ static int qeth_l3_hard_start_xmit(struct sk_buff *skb, struct net_device *dev)
 
        if (card->info.type != QETH_CARD_TYPE_IQD) {
                int len;
-               if (large_send)
+               if (use_tso)
                        len = ((unsigned long)tcp_hdr(new_skb) +
                                tcp_hdrlen(new_skb)) -
                                (unsigned long)new_skb->data;
@@ -2980,7 +2984,7 @@ static int qeth_l3_hard_start_xmit(struct sk_buff *skb, struct net_device *dev)
                        dev_kfree_skb_any(skb);
                if (card->options.performance_stats) {
                        nr_frags = skb_shinfo(new_skb)->nr_frags;
-                       if (large_send) {
+                       if (use_tso) {
                                card->perf_stats.large_send_bytes += tx_bytes;
                                card->perf_stats.large_send_cnt++;
                        }