s390/qeth: add stats counter for RX csum offload

This matches the statistics we gather for the TX offload path.
Signed-off-by: NKittipon Meesompop <kmeesomp@linux.vnet.ibm.com>
Signed-off-by: NJulian Wiedmann <jwi@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/s390/net/qeth_core.h

@@ -148,6 +148,7 @@ struct qeth_perf_stats {
 	unsigned int tx_csum;
 	unsigned int tx_lin;
 	unsigned int tx_linfail;
+	unsigned int rx_csum;
 };
 
 /* Routing stuff */
@@ -868,10 +869,13 @@ static inline void qeth_rx_csum(struct qeth_card *card, struct sk_buff *skb,
 				u8 flags)
 {
 	if ((card->dev->features & NETIF_F_RXCSUM) &&
-	    (flags & QETH_HDR_EXT_CSUM_TRANSP_REQ))
+	    (flags & QETH_HDR_EXT_CSUM_TRANSP_REQ)) {
 		skb->ip_summed = CHECKSUM_UNNECESSARY;
-	else
+		if (card->options.performance_stats)
+			card->perf_stats.rx_csum++;
+	} else {
 		skb->ip_summed = CHECKSUM_NONE;
+	}
 }
 
 static inline void qeth_tx_csum(struct sk_buff *skb, u8 *flags)

drivers/s390/net/qeth_core_main.c

@@ -6005,7 +6005,8 @@ static struct {
 	{"tx lin"},
 	{"tx linfail"},
 	{"cq handler count"},
-	{"cq handler time"}
+	{"cq handler time"},
+	{"rx csum"}
 };
 
 int qeth_core_get_sset_count(struct net_device *dev, int stringset)
@@ -6067,6 +6068,7 @@ void qeth_core_get_ethtool_stats(struct net_device *dev,
 	data[35] = card->perf_stats.tx_linfail;
 	data[36] = card->perf_stats.cq_cnt;
 	data[37] = card->perf_stats.cq_time;
+	data[38] = card->perf_stats.rx_csum;
 }
 EXPORT_SYMBOL_GPL(qeth_core_get_ethtool_stats);