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, 30 insertions, 8 deletions

diff --git a/include/linux/ethtool.h b/include/linux/ethtool.h
index 67b30940234b..3ab2b6a90419 100644
--- a/include/linux/ethtool.h
+++ b/include/linux/ethtool.h
@@ -597,6 +597,28 @@ struct ethtool_mm_stats {
 };
 
 /**
+ * struct ethtool_rxfh_param - RXFH (RSS) parameters
+ * @hfunc: Defines the current RSS hash function used by HW (or to be set to).
+ *	Valid values are one of the %ETH_RSS_HASH_*.
+ * @indir_size: On SET, the array size of the user buffer for the
+ *	indirection table, which may be zero, or
+ *	%ETH_RXFH_INDIR_NO_CHANGE.  On GET (read from the driver),
+ *	the array size of the hardware indirection table.
+ * @indir: The indirection table of size @indir_size entries.
+ * @key_size: On SET, the array size of the user buffer for the hash key,
+ *	which may be zero.  On GET (read from the driver), the size of the
+ *	hardware hash key.
+ * @key: The hash key of size @key_size bytes.
+ */
+struct ethtool_rxfh_param {
+	u8	hfunc;
+	u32	indir_size;
+	u32	*indir;
+	u32	key_size;
+	u8	*key;
+};
+
+/**
  * struct ethtool_ops - optional netdev operations
  * @cap_link_lanes_supported: indicates if the driver supports lanes
  *	parameter.
@@ -846,14 +868,14 @@ struct ethtool_ops {
 	int	(*reset)(struct net_device *, u32 *);
 	u32	(*get_rxfh_key_size)(struct net_device *);
 	u32	(*get_rxfh_indir_size)(struct net_device *);
-	int	(*get_rxfh)(struct net_device *, u32 *indir, u8 *key,
-			    u8 *hfunc);
-	int	(*set_rxfh)(struct net_device *, const u32 *indir,
-			    const u8 *key, const u8 hfunc);
-	int	(*get_rxfh_context)(struct net_device *, u32 *indir, u8 *key,
-				    u8 *hfunc, u32 rss_context);
-	int	(*set_rxfh_context)(struct net_device *, const u32 *indir,
-				    const u8 *key, const u8 hfunc,
+	int	(*get_rxfh)(struct net_device *, struct ethtool_rxfh_param *);
+	int	(*set_rxfh)(struct net_device *, struct ethtool_rxfh_param *,
+			    struct netlink_ext_ack *extack);
+	int	(*get_rxfh_context)(struct net_device *,
+				    struct ethtool_rxfh_param *,
+				    u32 rss_context);
+	int	(*set_rxfh_context)(struct net_device *,
+				    struct ethtool_rxfh_param *,
 				    u32 *rss_context, bool delete);
 	void	(*get_channels)(struct net_device *, struct ethtool_channels *);
 	int	(*set_channels)(struct net_device *, struct ethtool_channels *);