ethtool: Ethtool parameter to dynamically change tx_copybreak

Use new ethtool [sg]et_tunable() to set tx_copybread (inline threshold)

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Amir Vadai <amirv@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/uapi/linux/ethtool.h

diff --git a/include/uapi/linux/ethtool.h b/include/uapi/linux/ethtool.h
index 7a364f2..99b4305 100644
--- a/include/uapi/linux/ethtool.h
+++ b/include/uapi/linux/ethtool.h
@@ -212,6 +212,7 @@
 enum tunable_id {
 	ETHTOOL_ID_UNSPEC,
 	ETHTOOL_RX_COPYBREAK,
+	ETHTOOL_TX_COPYBREAK,
 };
 
 enum tunable_type_id {

net/core/ethtool.c

diff --git a/net/core/ethtool.c b/net/core/ethtool.c
index 27e61b8..1600aa2 100644
--- a/net/core/ethtool.c
+++ b/net/core/ethtool.c
@@ -1625,6 +1625,7 @@
 {
 	switch (tuna->id) {
 	case ETHTOOL_RX_COPYBREAK:
+	case ETHTOOL_TX_COPYBREAK:
 		if (tuna->len != sizeof(u32) ||
 		    tuna->type_id != ETHTOOL_TUNABLE_U32)
 			return -EINVAL;