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>

2 files changed, 39 insertions, 31 deletions

diff --git a/drivers/net/ethernet/sfc/siena/ethtool_common.c b/drivers/net/ethernet/sfc/siena/ethtool_common.c
index f590e87e5a23..20b64e3521cb 100644
--- a/drivers/net/ethernet/sfc/siena/ethtool_common.c
+++ b/drivers/net/ethernet/sfc/siena/ethtool_common.c
@@ -1164,8 +1164,8 @@ u32 efx_siena_ethtool_get_rxfh_key_size(struct net_device *net_dev)
 	return efx->type->rx_hash_key_size;
 }
 
-int efx_siena_ethtool_get_rxfh(struct net_device *net_dev, u32 *indir, u8 *key,
-			       u8 *hfunc)
+int efx_siena_ethtool_get_rxfh(struct net_device *net_dev,
+			       struct ethtool_rxfh_param *rxfh)
 {
 	struct efx_nic *efx = netdev_priv(net_dev);
 	int rc;
@@ -1174,24 +1174,27 @@ int efx_siena_ethtool_get_rxfh(struct net_device *net_dev, u32 *indir, u8 *key,
 	if (rc)
 		return rc;
 
-	if (hfunc)
-		*hfunc = ETH_RSS_HASH_TOP;
-	if (indir)
-		memcpy(indir, efx->rss_context.rx_indir_table,
+	rxfh->hfunc = ETH_RSS_HASH_TOP;
+	if (rxfh->indir)
+		memcpy(rxfh->indir, efx->rss_context.rx_indir_table,
 		       sizeof(efx->rss_context.rx_indir_table));
-	if (key)
-		memcpy(key, efx->rss_context.rx_hash_key,
+	if (rxfh->key)
+		memcpy(rxfh->key, efx->rss_context.rx_hash_key,
 		       efx->type->rx_hash_key_size);
 	return 0;
 }
 
-int efx_siena_ethtool_set_rxfh(struct net_device *net_dev, const u32 *indir,
-			       const u8 *key, const u8 hfunc)
+int efx_siena_ethtool_set_rxfh(struct net_device *net_dev,
+			       struct ethtool_rxfh_param *rxfh,
+			       struct netlink_ext_ack *extack)
 {
 	struct efx_nic *efx = netdev_priv(net_dev);
+	u32 *indir = rxfh->indir;
+	u8 *key = rxfh->key;
 
 	/* Hash function is Toeplitz, cannot be changed */
-	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 (!indir && !key)
 		return 0;
@@ -1204,8 +1207,9 @@ int efx_siena_ethtool_set_rxfh(struct net_device *net_dev, const u32 *indir,
 	return efx->type->rx_push_rss_config(efx, true, indir, key);
 }
 
-int efx_siena_ethtool_get_rxfh_context(struct net_device *net_dev, u32 *indir,
-				       u8 *key, u8 *hfunc, u32 rss_context)
+int efx_siena_ethtool_get_rxfh_context(struct net_device *net_dev,
+				       struct ethtool_rxfh_param *rxfh,
+				       u32 rss_context)
 {
 	struct efx_nic *efx = netdev_priv(net_dev);
 	struct efx_rss_context *ctx;
@@ -1224,31 +1228,34 @@ int efx_siena_ethtool_get_rxfh_context(struct net_device *net_dev, u32 *indir,
 	if (rc)
 		goto out_unlock;
 
-	if (hfunc)
-		*hfunc = ETH_RSS_HASH_TOP;
-	if (indir)
-		memcpy(indir, ctx->rx_indir_table, sizeof(ctx->rx_indir_table));
-	if (key)
-		memcpy(key, ctx->rx_hash_key, efx->type->rx_hash_key_size);
+	rxfh->hfunc = ETH_RSS_HASH_TOP;
+	if (rxfh->indir)
+		memcpy(rxfh->indir, ctx->rx_indir_table,
+		       sizeof(ctx->rx_indir_table));
+	if (rxfh->key)
+		memcpy(rxfh->key, ctx->rx_hash_key,
+		       efx->type->rx_hash_key_size);
 out_unlock:
 	mutex_unlock(&efx->rss_lock);
 	return rc;
 }
 
 int efx_siena_ethtool_set_rxfh_context(struct net_device *net_dev,
-				       const u32 *indir, const u8 *key,
-				       const u8 hfunc, u32 *rss_context,
-				       bool delete)
+				       struct ethtool_rxfh_param *rxfh,
+				       u32 *rss_context, bool delete)
 {
 	struct efx_nic *efx = netdev_priv(net_dev);
 	struct efx_rss_context *ctx;
+	u32 *indir = rxfh->indir;
 	bool allocated = false;
+	u8 *key = rxfh->key;
 	int rc;
 
 	if (!efx->type->rx_push_rss_context_config)
 		return -EOPNOTSUPP;
 	/* Hash function is Toeplitz, cannot be changed */
-	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;
 
 	mutex_lock(&efx->rss_lock);
diff --git a/drivers/net/ethernet/sfc/siena/ethtool_common.h b/drivers/net/ethernet/sfc/siena/ethtool_common.h
index 04b375dc6800..2f892f8eff70 100644
--- a/drivers/net/ethernet/sfc/siena/ethtool_common.h
+++ b/drivers/net/ethernet/sfc/siena/ethtool_common.h
@@ -41,16 +41,17 @@ int efx_siena_ethtool_set_rxnfc(struct net_device *net_dev,
 				struct ethtool_rxnfc *info);
 u32 efx_siena_ethtool_get_rxfh_indir_size(struct net_device *net_dev);
 u32 efx_siena_ethtool_get_rxfh_key_size(struct net_device *net_dev);
-int efx_siena_ethtool_get_rxfh(struct net_device *net_dev, u32 *indir, u8 *key,
-			       u8 *hfunc);
+int efx_siena_ethtool_get_rxfh(struct net_device *net_dev,
+			       struct ethtool_rxfh_param *rxfh);
 int efx_siena_ethtool_set_rxfh(struct net_device *net_dev,
-			       const u32 *indir, const u8 *key, const u8 hfunc);
-int efx_siena_ethtool_get_rxfh_context(struct net_device *net_dev, u32 *indir,
-				       u8 *key, u8 *hfunc, u32 rss_context);
+			       struct ethtool_rxfh_param *rxfh,
+			       struct netlink_ext_ack *extack);
+int efx_siena_ethtool_get_rxfh_context(struct net_device *net_dev,
+				       struct ethtool_rxfh_param *rxfh,
+				       u32 rss_context);
 int efx_siena_ethtool_set_rxfh_context(struct net_device *net_dev,
-				       const u32 *indir, const u8 *key,
-				       const u8 hfunc, u32 *rss_context,
-				       bool delete);
+				       struct ethtool_rxfh_param *rxfh,
+				       u32 *rss_context, bool delete);
 int efx_siena_ethtool_reset(struct net_device *net_dev, u32 *flags);
 int efx_siena_ethtool_get_module_eeprom(struct net_device *net_dev,
 					struct ethtool_eeprom *ee,