[PATCH net-next v2 4/4] amd-xgbe: add ethtool jumbo frame selftest

[Raju Rangoju <Raju.Rangoju@amd.com>]

Adds support for jumbo frame selftest. Works only for
mtu size greater than 1500.

Signed-off-by: Raju Rangoju <Raju.Rangoju@amd.com>
---
 drivers/net/ethernet/amd/xgbe/xgbe-selftest.c | 26 +++++++++++++++++--
 1 file changed, 24 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/amd/xgbe/xgbe-selftest.c b/drivers/net/ethernet/amd/xgbe/xgbe-selftest.c
index ae7c8d6aca61..717e03040420 100644
--- a/drivers/net/ethernet/amd/xgbe/xgbe-selftest.c
+++ b/drivers/net/ethernet/amd/xgbe/xgbe-selftest.c
@@ -199,10 +199,18 @@ static int xgbe_test_loopback_validate(struct sk_buff *skb,
 	struct iphdr *ih;
 	struct tcphdr *th;
 	struct udphdr *uh;
+	int eat;
 
 	skb = skb_unshare(skb, GFP_ATOMIC);
 	if (!skb)
-		goto out;
+		return -1;
+
+	eat = (skb->tail + skb->data_len) - skb->end;
+	if (eat > 0 && skb_shared(skb)) {
+		skb = skb_share_check(skb, GFP_ATOMIC);
+		if (!skb)
+			return -1;
+	}
 
 	if (skb_linearize(skb))
 		goto out;
@@ -371,6 +379,17 @@ static int xgbe_test_sph(struct xgbe_prv_data *pdata)
 	return 0;
 }
 
+static int xgbe_test_jumbo(struct xgbe_prv_data *pdata)
+{
+	struct xgbe_pkt_attrs attr = {};
+	int size = pdata->rx_buf_size;
+
+	attr.dst = pdata->netdev->dev_addr;
+	attr.max_size = size - ETH_FCS_LEN;
+
+	return __xgbe_test_loopback(pdata, &attr);
+}
+
 static const struct xgbe_test xgbe_selftests[] = {
 	{
 		.name = "MAC Loopback               ",
@@ -384,8 +403,11 @@ static const struct xgbe_test xgbe_selftests[] = {
 		.name = "Split Header               ",
 		.lb = XGBE_LOOPBACK_PHY,
 		.fn = xgbe_test_sph,
+	}, {
+		.name = "Jumbo Frame                ",
+		.lb = XGBE_LOOPBACK_PHY,
+		.fn = xgbe_test_jumbo,
 	},
-
 };
 
 void xgbe_selftest_run(struct net_device *dev,
-- 
2.34.1