net: enetc: check whether the RSS algorithm is Toeplitz

Both ENETC v1 and v4 only provide Toeplitz RSS support. This patch adds
a validation check to reject attempts to configure other RSS algorithms,
avoiding misleading configuration options for users.

Fixes: d382563 ("enetc: Add RFS and RSS support")
Signed-off-by: Wei Fang <[email protected]>
Reviewed-by: Clark Wang <[email protected]>
Reviewed-by: Claudiu Manoil <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

Author: WeiFang-NXP

drivers/net/ethernet/freescale/enetc/enetc_ethtool.c

@@ -795,6 +795,10 @@ static int enetc_set_rxfh(struct net_device *ndev,
 	struct enetc_si *si = priv->si;
 	int err = 0;
 
+	if (rxfh->hfunc != ETH_RSS_HASH_NO_CHANGE &&
+	    rxfh->hfunc != ETH_RSS_HASH_TOP)
+		return -EOPNOTSUPP;
+
 	/* set hash key, if PF */
 	if (rxfh->key && enetc_si_is_pf(si))
 		enetc_set_rss_key(si, rxfh->key);