igc: add support to get MAC Merge data via ethtool

Implement "ethtool --show-mm" callback for IGC.

Tested with command:
$ ethtool --show-mm enp1s0.
  MAC Merge layer state for enp1s0:
  pMAC enabled: on
  TX enabled: on
  TX active: on
  TX minimum fragment size: 64
  RX minimum fragment size: 60
  Verify enabled: on
  Verify time: 128
  Max verify time: 128
  Verification status: SUCCEEDED

Verified that the fields value are retrieved correctly.

Reviewed-by: Vladimir Oltean <[email protected]>
Signed-off-by: Faizal Rahim <[email protected]>
Tested-by: Mor Bar-Gabay <[email protected]>
Signed-off-by: Tony Nguyen <[email protected]>

Author: Faizal Rahim

drivers/net/ethernet/intel/igc/igc_ethtool.c

@@ -1782,6 +1782,19 @@ static int igc_ethtool_set_eee(struct net_device *netdev,
 	return 0;
 }
 
+static int igc_ethtool_get_mm(struct net_device *netdev,
+			      struct ethtool_mm_state *cmd)
+{
+	struct igc_adapter *adapter = netdev_priv(netdev);
+	struct igc_fpe_t *fpe = &adapter->fpe;
+
+	ethtool_mmsv_get_mm(&fpe->mmsv, cmd);
+	cmd->tx_min_frag_size = fpe->tx_min_frag_size;
+	cmd->rx_min_frag_size = IGC_RX_MIN_FRAG_SIZE;
+
+	return 0;
+}
+
 static int igc_ethtool_set_mm(struct net_device *netdev,
 			      struct ethtool_mm_cfg *cmd,
 			      struct netlink_ext_ack *extack)
@@ -2101,6 +2114,7 @@ static const struct ethtool_ops igc_ethtool_ops = {
 	.get_link_ksettings	= igc_ethtool_get_link_ksettings,
 	.set_link_ksettings	= igc_ethtool_set_link_ksettings,
 	.self_test		= igc_ethtool_diag_test,
+	.get_mm			= igc_ethtool_get_mm,
 	.set_mm			= igc_ethtool_set_mm,
 };
 

drivers/net/ethernet/intel/igc/igc_tsn.h

@@ -4,6 +4,7 @@
 #ifndef _IGC_TSN_H_
 #define _IGC_TSN_H_
 
+#define IGC_RX_MIN_FRAG_SIZE		60
 #define SMD_FRAME_SIZE			60
 
 enum igc_txd_popts_type {