eth: fbnic: support setting RSS configuration

Let the user program the RSS indirection table and the RSS key.
Straightforward implementation. Track the changes and don't bother
poking the HW if user asked for a config identical to what's already
programmed. The device only supports Toeplitz hash.

Similarly to the GET support - all the real code that does the programming
was part of initial driver submission, already.

Signed-off-by: Alexander Duyck <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

Author: ahduyck

drivers/net/ethernet/meta/fbnic/fbnic_ethtool.c

@@ -201,6 +201,60 @@ fbnic_get_rxfh(struct net_device *netdev, struct ethtool_rxfh_param *rxfh)
 	return 0;
 }
 
+static unsigned int
+fbnic_set_indir(struct fbnic_net *fbn, unsigned int idx, const u32 *indir)
+{
+	unsigned int i, changes = 0;
+
+	for (i = 0; i < FBNIC_RPC_RSS_TBL_SIZE; i++) {
+		if (fbn->indir_tbl[idx][i] == indir[i])
+			continue;
+
+		fbn->indir_tbl[idx][i] = indir[i];
+		changes++;
+	}
+
+	return changes;
+}
+
+static int
+fbnic_set_rxfh(struct net_device *netdev, struct ethtool_rxfh_param *rxfh,
+	       struct netlink_ext_ack *extack)
+{
+	struct fbnic_net *fbn = netdev_priv(netdev);
+	unsigned int i, changes = 0;
+
+	if (rxfh->hfunc != ETH_RSS_HASH_NO_CHANGE &&
+	    rxfh->hfunc != ETH_RSS_HASH_TOP)
+		return -EINVAL;
+
+	if (rxfh->key) {
+		u32 rss_key = 0;
+
+		for (i = FBNIC_RPC_RSS_KEY_BYTE_LEN; i--;) {
+			rss_key >>= 8;
+			rss_key |= (u32)(rxfh->key[i]) << 24;
+
+			if (i % 4)
+				continue;
+
+			if (fbn->rss_key[i / 4] == rss_key)
+				continue;
+
+			fbn->rss_key[i / 4] = rss_key;
+			changes++;
+		}
+	}
+
+	if (rxfh->indir)
+		changes += fbnic_set_indir(fbn, 0, rxfh->indir);
+
+	if (changes && netif_running(netdev))
+		fbnic_rss_reinit_hw(fbn->fbd, fbn);
+
+	return 0;
+}
+
 static int
 fbnic_get_ts_info(struct net_device *netdev,
 		  struct kernel_ethtool_ts_info *tsinfo)
@@ -312,6 +366,7 @@ static const struct ethtool_ops fbnic_ethtool_ops = {
 	.get_rxfh_key_size	= fbnic_get_rxfh_key_size,
 	.get_rxfh_indir_size	= fbnic_get_rxfh_indir_size,
 	.get_rxfh		= fbnic_get_rxfh,
+	.set_rxfh		= fbnic_set_rxfh,
 	.get_ts_info		= fbnic_get_ts_info,
 	.get_ts_stats		= fbnic_get_ts_stats,
 	.get_eth_mac_stats	= fbnic_get_eth_mac_stats,