ethtool: Add common function for filling out strings

Add a function to handle the common pattern of printing a string into the
ethtool strings interface and incrementing the string pointer by the
ETH_GSTRING_LEN. Most of the drivers end up doing this and several have
implemented their own versions of this function so it would make sense to
consolidate on one implementation.

Signed-off-by: Alexander Duyck <alexanderduyck@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 9 insertions, 0 deletions

diff --git a/include/linux/ethtool.h b/include/linux/ethtool.h
index ec4cd3921c67..3583f7fc075c 100644
--- a/include/linux/ethtool.h
+++ b/include/linux/ethtool.h
@@ -571,4 +571,13 @@ struct ethtool_phy_ops {
  */
 void ethtool_set_ethtool_phy_ops(const struct ethtool_phy_ops *ops);
 
+/**
+ * ethtool_sprintf - Write formatted string to ethtool string data
+ * @data: Pointer to start of string to update
+ * @fmt: Format of string to write
+ *
+ * Write formatted string to data. Update data to point at start of
+ * next string.
+ */
+extern __printf(2, 3) void ethtool_sprintf(u8 **data, const char *fmt, ...);
 #endif /* _LINUX_ETHTOOL_H */