Modify ethtool_set_rxfh() to use the new ethtool_get_rx_ring_count()
helper function for retrieving the number of RX rings instead of
directly calling get_rxnfc with ETHTOOL_GRXRINGS.

This way, we can leverage the new helper if it is available in ethtool_ops.

Signed-off-by: Breno Leitao <leitao@debian.org>
---
 net/ethtool/ioctl.c | 16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/net/ethtool/ioctl.c b/net/ethtool/ioctl.c
index 8493ee200601e..d61e34751adc8 100644
--- a/net/ethtool/ioctl.c
+++ b/net/ethtool/ioctl.c
@@ -1531,14 +1531,14 @@ static noinline_for_stack int ethtool_set_rxfh(struct net_device *dev,
 	struct ethtool_rxfh_param rxfh_dev = {};
 	struct ethtool_rxfh_context *ctx = NULL;
 	struct netlink_ext_ack *extack = NULL;
-	struct ethtool_rxnfc rx_rings;
 	struct ethtool_rxfh rxfh;
 	bool create = false;
+	int num_rx_rings;
 	u8 *rss_config;
 	int ntf = 0;
 	int ret;
 
-	if (!ops->get_rxnfc || !ops->set_rxfh)
+	if (!ops->set_rxfh)
 		return -EOPNOTSUPP;
 
 	if (ops->get_rxfh_indir_size)
@@ -1594,10 +1594,11 @@ static noinline_for_stack int ethtool_set_rxfh(struct net_device *dev,
 	if (!rss_config)
 		return -ENOMEM;
 
-	rx_rings.cmd = ETHTOOL_GRXRINGS;
-	ret = ops->get_rxnfc(dev, &rx_rings, NULL);
-	if (ret)
+	num_rx_rings = ethtool_get_rx_ring_count(dev);
+	if (num_rx_rings < 0) {
+		ret = num_rx_rings;
 		goto out_free;
+	}
 
 	/* rxfh.indir_size == 0 means reset the indir table to default (master
 	 * context) or delete the context (other RSS contexts).
@@ -1610,7 +1611,7 @@ static noinline_for_stack int ethtool_set_rxfh(struct net_device *dev,
 		rxfh_dev.indir_size = dev_indir_size;
 		ret = ethtool_copy_validate_indir(rxfh_dev.indir,
 						  useraddr + rss_cfg_offset,
-						  rx_rings.data,
+						  num_rx_rings,
 						  rxfh.indir_size);
 		if (ret)
 			goto out_free;
@@ -1622,7 +1623,8 @@ static noinline_for_stack int ethtool_set_rxfh(struct net_device *dev,
 			rxfh_dev.indir_size = dev_indir_size;
 			indir = rxfh_dev.indir;
 			for (i = 0; i < dev_indir_size; i++)
-				indir[i] = ethtool_rxfh_indir_default(i, rx_rings.data);
+				indir[i] =
+					ethtool_rxfh_indir_default(i, num_rx_rings);
 		} else {
 			rxfh_dev.rss_delete = true;
 		}

-- 
2.47.3