summaryrefslogtreecommitdiff
path: root/drivers/s390/net/qeth_core_main.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/s390/net/qeth_core_main.c')
-rw-r--r--drivers/s390/net/qeth_core_main.c32
1 files changed, 32 insertions, 0 deletions
diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c
index 49b9efeba1bd..430e3214f7e2 100644
--- a/drivers/s390/net/qeth_core_main.c
+++ b/drivers/s390/net/qeth_core_main.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
/*
* Copyright IBM Corp. 2007, 2009
* Author(s): Utz Bacher <utz.bacher@de.ibm.com>,
@@ -19,6 +20,11 @@
#include <linux/mii.h>
#include <linux/kthread.h>
#include <linux/slab.h>
+#include <linux/if_vlan.h>
+#include <linux/netdevice.h>
+#include <linux/netdev_features.h>
+#include <linux/skbuff.h>
+
#include <net/iucv/af_iucv.h>
#include <net/dsfield.h>
@@ -6438,6 +6444,32 @@ netdev_features_t qeth_fix_features(struct net_device *dev,
}
EXPORT_SYMBOL_GPL(qeth_fix_features);
+netdev_features_t qeth_features_check(struct sk_buff *skb,
+ struct net_device *dev,
+ netdev_features_t features)
+{
+ /* GSO segmentation builds skbs with
+ * a (small) linear part for the headers, and
+ * page frags for the data.
+ * Compared to a linear skb, the header-only part consumes an
+ * additional buffer element. This reduces buffer utilization, and
+ * hurts throughput. So compress small segments into one element.
+ */
+ if (netif_needs_gso(skb, features)) {
+ /* match skb_segment(): */
+ unsigned int doffset = skb->data - skb_mac_header(skb);
+ unsigned int hsize = skb_shinfo(skb)->gso_size;
+ unsigned int hroom = skb_headroom(skb);
+
+ /* linearize only if resulting skb allocations are order-0: */
+ if (SKB_DATA_ALIGN(hroom + doffset + hsize) <= SKB_MAX_HEAD(0))
+ features &= ~NETIF_F_SG;
+ }
+
+ return vlan_features_check(skb, features);
+}
+EXPORT_SYMBOL_GPL(qeth_features_check);
+
static int __init qeth_core_init(void)
{
int rc;