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, 20 insertions, 22 deletions

diff --git a/drivers/net/ethernet/intel/iavf/iavf_ethtool.c b/drivers/net/ethernet/intel/iavf/iavf_ethtool.c
index 631c7cfdc814..c376a489e4c2 100644
--- a/drivers/net/ethernet/intel/iavf/iavf_ethtool.c
+++ b/drivers/net/ethernet/intel/iavf/iavf_ethtool.c
@@ -1894,27 +1894,24 @@ static u32 iavf_get_rxfh_indir_size(struct net_device *netdev)
 /**
  * iavf_get_rxfh - get the rx flow hash indirection table
  * @netdev: network interface device structure
- * @indir: indirection table
- * @key: hash key
- * @hfunc: hash function in use
+ * @rxfh: pointer to param struct (indir, key, hfunc)
  *
  * Reads the indirection table directly from the hardware. Always returns 0.
  **/
-static int iavf_get_rxfh(struct net_device *netdev, u32 *indir, u8 *key,
-			 u8 *hfunc)
+static int iavf_get_rxfh(struct net_device *netdev,
+			 struct ethtool_rxfh_param *rxfh)
 {
 	struct iavf_adapter *adapter = netdev_priv(netdev);
 	u16 i;
 
-	if (hfunc)
-		*hfunc = ETH_RSS_HASH_TOP;
-	if (key)
-		memcpy(key, adapter->rss_key, adapter->rss_key_size);
+	rxfh->hfunc = ETH_RSS_HASH_TOP;
+	if (rxfh->key)
+		memcpy(rxfh->key, adapter->rss_key, adapter->rss_key_size);
 
-	if (indir)
+	if (rxfh->indir)
 		/* Each 32 bits pointed by 'indir' is stored with a lut entry */
 		for (i = 0; i < adapter->rss_lut_size; i++)
-			indir[i] = (u32)adapter->rss_lut[i];
+			rxfh->indir[i] = (u32)adapter->rss_lut[i];
 
 	return 0;
 }
@@ -1922,33 +1919,34 @@ static int iavf_get_rxfh(struct net_device *netdev, u32 *indir, u8 *key,
 /**
  * iavf_set_rxfh - set the rx flow hash indirection table
  * @netdev: network interface device structure
- * @indir: indirection table
- * @key: hash key
- * @hfunc: hash function to use
+ * @rxfh: pointer to param struct (indir, key, hfunc)
+ * @extack: extended ACK from the Netlink message
  *
  * Returns -EINVAL if the table specifies an invalid queue id, otherwise
  * returns 0 after programming the table.
  **/
-static int iavf_set_rxfh(struct net_device *netdev, const u32 *indir,
-			 const u8 *key, const u8 hfunc)
+static int iavf_set_rxfh(struct net_device *netdev,
+			 struct ethtool_rxfh_param *rxfh,
+			 struct netlink_ext_ack *extack)
 {
 	struct iavf_adapter *adapter = netdev_priv(netdev);
 	u16 i;
 
 	/* Only support toeplitz hash function */
-	if (hfunc != ETH_RSS_HASH_NO_CHANGE && hfunc != ETH_RSS_HASH_TOP)
+	if (rxfh->hfunc != ETH_RSS_HASH_NO_CHANGE &&
+	    rxfh->hfunc != ETH_RSS_HASH_TOP)
 		return -EOPNOTSUPP;
 
-	if (!key && !indir)
+	if (!rxfh->key && !rxfh->indir)
 		return 0;
 
-	if (key)
-		memcpy(adapter->rss_key, key, adapter->rss_key_size);
+	if (rxfh->key)
+		memcpy(adapter->rss_key, rxfh->key, adapter->rss_key_size);
 
-	if (indir) {
+	if (rxfh->indir) {
 		/* Each 32 bits pointed by 'indir' is stored with a lut entry */
 		for (i = 0; i < adapter->rss_lut_size; i++)
-			adapter->rss_lut[i] = (u8)(indir[i]);
+			adapter->rss_lut[i] = (u8)(rxfh->indir[i]);
 	}
 
 	return iavf_config_rss(adapter);