net: ethtool: use the new helper in rss_set_prep_indir()

Refactor rss_set_prep_indir() to utilize the new
ethtool_get_rx_ring_count() helper for determining the number of RX
rings, replacing the direct use of get_rxnfc with ETHTOOL_GRXRINGS.

This ensures compatibility with both legacy and new ethtool_ops
interfaces by transparently multiplexing between them.

Signed-off-by: Breno Leitao <leitao@debian.org>
Link: https://patch.msgid.link/20250917-gxrings-v4-7-dae520e2e1cb@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/net/ethtool/rss.c b/net/ethtool/rss.c
index 202d95e8bf3e17ed60c9fd0ed8edc68108e93c51..4dced53be4b3bb2c7c70fcdfc3dd22ef0c8ca2ce 100644 (file)
--- a/net/ethtool/rss.c
+++ b/net/ethtool/rss.c
@@ -620,23 +620,22 @@ rss_set_prep_indir(struct net_device *dev, struct genl_info *info,
                   struct rss_reply_data *data, struct ethtool_rxfh_param *rxfh,
                   bool *reset, bool *mod)
 {
-       const struct ethtool_ops *ops = dev->ethtool_ops;
        struct netlink_ext_ack *extack = info->extack;
        struct nlattr **tb = info->attrs;
-       struct ethtool_rxnfc rx_rings;
        size_t alloc_size;
+       int num_rx_rings;
        u32 user_size;
        int i, err;
 
        if (!tb[ETHTOOL_A_RSS_INDIR])
                return 0;
-       if (!data->indir_size || !ops->get_rxnfc)
+       if (!data->indir_size)
                return -EOPNOTSUPP;
 
-       rx_rings.cmd = ETHTOOL_GRXRINGS;
-       err = ops->get_rxnfc(dev, &rx_rings, NULL);
-       if (err)
+       err = ethtool_get_rx_ring_count(dev);
+       if (err < 0)
                return err;
+       num_rx_rings = err;
 
        if (nla_len(tb[ETHTOOL_A_RSS_INDIR]) % 4) {
                NL_SET_BAD_ATTR(info->extack, tb[ETHTOOL_A_RSS_INDIR]);
@@ -665,7 +664,7 @@ rss_set_prep_indir(struct net_device *dev, struct genl_info *info,
 
        nla_memcpy(rxfh->indir, tb[ETHTOOL_A_RSS_INDIR], alloc_size);
        for (i = 0; i < user_size; i++) {
-               if (rxfh->indir[i] < rx_rings.data)
+               if (rxfh->indir[i] < num_rx_rings)
                        continue;
 
                NL_SET_ERR_MSG_ATTR_FMT(extack, tb[ETHTOOL_A_RSS_INDIR],
@@ -682,7 +681,7 @@ rss_set_prep_indir(struct net_device *dev, struct genl_info *info,
        } else {
                for (i = 0; i < data->indir_size; i++)
                        rxfh->indir[i] =
-                               ethtool_rxfh_indir_default(i, rx_rings.data);
+                               ethtool_rxfh_indir_default(i, num_rx_rings);
        }
 
        *mod |= memcmp(rxfh->indir, data->indir_table, data->indir_size);