net: ethtool: pass a pointer to parameters to get/set_rxfh ethtool ops

The get/set_rxfh ethtool ops currently takes the rxfh (RSS) parameters
as direct function arguments. This will force us to change the API (and
all drivers' functions) every time some new parameters are added.

This is part 1/2 of the fix, as suggested in [1]:

- First simplify the code by always providing a pointer to all params
   (indir, key and func); the fact that some of them may be NULL seems
   like a weird historic thing or a premature optimization.
   It will simplify the drivers if all pointers are always present.

 - Then make the functions take a dev pointer, and a pointer to a
   single struct wrapping all arguments. The set_* should also take
   an extack.

Link: https://lore.kernel.org/netdev/20231121152906.2dd5f487@kernel.org/ [1]
Suggested-by: Jakub Kicinski <kuba@kernel.org>
Suggested-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Ahmed Zaki <ahmed.zaki@intel.com>
Link: https://lore.kernel.org/r/20231213003321.605376-2-ahmed.zaki@intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 13 insertions, 12 deletions

diff --git a/drivers/net/ethernet/cisco/enic/enic_ethtool.c b/drivers/net/ethernet/cisco/enic/enic_ethtool.c
index 08b7cc0a1809..241906697019 100644
--- a/drivers/net/ethernet/cisco/enic/enic_ethtool.c
+++ b/drivers/net/ethernet/cisco/enic/enic_ethtool.c
@@ -568,31 +568,32 @@ static u32 enic_get_rxfh_key_size(struct net_device *netdev)
 	return ENIC_RSS_LEN;
 }
 
-static int enic_get_rxfh(struct net_device *netdev, u32 *indir, u8 *hkey,
-			 u8 *hfunc)
+static int enic_get_rxfh(struct net_device *netdev,
+			 struct ethtool_rxfh_param *rxfh)
 {
 	struct enic *enic = netdev_priv(netdev);
 
-	if (hkey)
-		memcpy(hkey, enic->rss_key, ENIC_RSS_LEN);
+	if (rxfh->key)
+		memcpy(rxfh->key, enic->rss_key, ENIC_RSS_LEN);
 
-	if (hfunc)
-		*hfunc = ETH_RSS_HASH_TOP;
+	rxfh->hfunc = ETH_RSS_HASH_TOP;
 
 	return 0;
 }
 
-static int enic_set_rxfh(struct net_device *netdev, const u32 *indir,
-			 const u8 *hkey, const u8 hfunc)
+static int enic_set_rxfh(struct net_device *netdev,
+			 struct ethtool_rxfh_param *rxfh,
+			 struct netlink_ext_ack *extack)
 {
 	struct enic *enic = netdev_priv(netdev);
 
-	if ((hfunc != ETH_RSS_HASH_NO_CHANGE && hfunc != ETH_RSS_HASH_TOP) ||
-	    indir)
+	if (rxfh->indir ||
+	    (rxfh->hfunc != ETH_RSS_HASH_NO_CHANGE &&
+	     rxfh->hfunc != ETH_RSS_HASH_TOP))
 		return -EINVAL;
 
-	if (hkey)
-		memcpy(enic->rss_key, hkey, ENIC_RSS_LEN);
+	if (rxfh->key)
+		memcpy(enic->rss_key, rxfh->key, ENIC_RSS_LEN);
 
 	return __enic_set_rsskey(enic);
 }