ethtool: Clean up definitions of rule location arrays in RX NFC

Correct the description of ethtool_rxnfc::rule_locs; it is an array
of currently used locations, not all possible valid locations.

Add note that drivers must not use ethtool_rxnfc::rule_locs.

The rule_locs argument to ethtool_ops::get_rxnfc is either NULL or a
pointer to an array of u32, so change the parameter type accordingly.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 4 insertions, 3 deletions

diff --git a/include/linux/ethtool.h b/include/linux/ethtool.h
index b5d189367a02..5d4a06accd82 100644
--- a/include/linux/ethtool.h
+++ b/include/linux/ethtool.h
@@ -479,7 +479,7 @@ struct ethtool_rx_flow_spec {
  * @data: Command-dependent value
  * @fs: Flow classification rule
  * @rule_cnt: Number of rules to be affected
- * @rule_locs: Array of valid rule locations
+ * @rule_locs: Array of used rule locations
  *
  * For %ETHTOOL_GRXFH and %ETHTOOL_SRXFH, @data is a bitmask indicating
  * the fields included in the flow hash, e.g. %RXH_IP_SRC.  The following
@@ -497,7 +497,8 @@ struct ethtool_rx_flow_spec {
  * For %ETHTOOL_GRXCLSRLALL, @rule_cnt specifies the array size of the
  * user buffer for @rule_locs on entry.  On return, @data is the size
  * of the rule table and @rule_locs contains the locations of the
- * defined rules.
+ * defined rules.  Drivers must use the second parameter to get_rxnfc()
+ * instead of @rule_locs.
  *
  * For %ETHTOOL_SRXCLSRLINS, @fs specifies the rule to add or update.
  * @fs.@location specifies the location to use and must not be ignored.
@@ -939,7 +940,7 @@ struct ethtool_ops {
         int     (*set_priv_flags)(struct net_device *, u32);
         int     (*get_sset_count)(struct net_device *, int);
         int     (*get_rxnfc)(struct net_device *,
-                             struct ethtool_rxnfc *, void *);
+                             struct ethtool_rxnfc *, u32 *rule_locs);
         int     (*set_rxnfc)(struct net_device *, struct ethtool_rxnfc *);
         int     (*flash_device)(struct net_device *, struct ethtool_flash *);
         int     (*reset)(struct net_device *, u32 *);