sfc: support setting MTU even if not privileged to configure MAC fully

Unprivileged functions (such as VFs) may set their MTU by use of the
 'control' field of MC_CMD_SET_MAC_EXT, as used in efx_mcdi_set_mtu().
If calling efx_ef10_mac_reconfigure() from efx_change_mtu(), and the
 NIC supports the above (SET_MAC_ENHANCED capability), use it rather
 than efx_mcdi_set_mac().
Signed-off-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/sfc/ef10.c

@@ -3306,18 +3306,15 @@ static int efx_ef10_set_mac_address(struct efx_nic *efx)
 	return rc;
 }
 
-static int efx_ef10_mac_reconfigure(struct efx_nic *efx)
+static int efx_ef10_mac_reconfigure(struct efx_nic *efx, bool mtu_only)
 {
-	efx_mcdi_filter_sync_rx_mode(efx);
-
-	return efx_mcdi_set_mac(efx);
-}
+	WARN_ON(!mutex_is_locked(&efx->mac_lock));
 
-static int efx_ef10_mac_reconfigure_vf(struct efx_nic *efx)
-{
 	efx_mcdi_filter_sync_rx_mode(efx);
 
-	return 0;
+	if (mtu_only && efx_has_cap(efx, SET_MAC_ENHANCED))
+		return efx_mcdi_set_mtu(efx);
+	return efx_mcdi_set_mac(efx);
 }
 
 static int efx_ef10_start_bist(struct efx_nic *efx, u32 bist_type)
@@ -4038,7 +4035,7 @@ const struct efx_nic_type efx_hunt_a0_vf_nic_type = {
 	.stop_stats = efx_port_dummy_op_void,
 	.set_id_led = efx_mcdi_set_id_led,
 	.push_irq_moderation = efx_ef10_push_irq_moderation,
-	.reconfigure_mac = efx_ef10_mac_reconfigure_vf,
+	.reconfigure_mac = efx_ef10_mac_reconfigure,
 	.check_mac_fault = efx_mcdi_mac_check_fault,
 	.reconfigure_port = efx_mcdi_port_reconfigure,
 	.get_wol = efx_ef10_get_wol_vf,

drivers/net/ethernet/sfc/efx.c

@@ -169,10 +169,6 @@ static int efx_init_port(struct efx_nic *efx)
 
 	efx->port_initialized = true;
 
-	/* Reconfigure the MAC before creating dma queues (required for
-	 * Falcon/A1 where RX_INGR_EN/TX_DRAIN_EN isn't supported) */
-	efx_mac_reconfigure(efx);
-
 	/* Ensure the PHY advertises the correct flow control settings */
 	rc = efx->phy_op->reconfigure(efx);
 	if (rc && rc != -EPERM)

drivers/net/ethernet/sfc/efx_common.c

@@ -139,11 +139,11 @@ void efx_destroy_reset_workqueue(void)
 /* We assume that efx->type->reconfigure_mac will always try to sync RX
  * filters and therefore needs to read-lock the filter table against freeing
  */
-void efx_mac_reconfigure(struct efx_nic *efx)
+void efx_mac_reconfigure(struct efx_nic *efx, bool mtu_only)
 {
 	if (efx->type->reconfigure_mac) {
 		down_read(&efx->filter_sem);
-		efx->type->reconfigure_mac(efx);
+		efx->type->reconfigure_mac(efx, mtu_only);
 		up_read(&efx->filter_sem);
 	}
 }
@@ -158,7 +158,7 @@ static void efx_mac_work(struct work_struct *data)
 
 	mutex_lock(&efx->mac_lock);
 	if (efx->port_enabled)
-		efx_mac_reconfigure(efx);
+		efx_mac_reconfigure(efx, false);
 	mutex_unlock(&efx->mac_lock);
 }
 
@@ -190,7 +190,7 @@ int efx_set_mac_address(struct net_device *net_dev, void *data)
 
 	/* Reconfigure the MAC */
 	mutex_lock(&efx->mac_lock);
-	efx_mac_reconfigure(efx);
+	efx_mac_reconfigure(efx, false);
 	mutex_unlock(&efx->mac_lock);
 
 	return 0;
@@ -304,7 +304,7 @@ int efx_change_mtu(struct net_device *net_dev, int new_mtu)
 
 	mutex_lock(&efx->mac_lock);
 	net_dev->mtu = new_mtu;
-	efx_mac_reconfigure(efx);
+	efx_mac_reconfigure(efx, true);
 	mutex_unlock(&efx->mac_lock);
 
 	efx_start_all(efx);
@@ -486,7 +486,7 @@ static void efx_start_port(struct efx_nic *efx)
 	efx->port_enabled = true;
 
 	/* Ensure MAC ingress/egress is enabled */
-	efx_mac_reconfigure(efx);
+	efx_mac_reconfigure(efx, false);
 
 	mutex_unlock(&efx->mac_lock);
 }

drivers/net/ethernet/sfc/efx_common.h

@@ -95,7 +95,7 @@ static inline void efx_init_mcdi_logging(struct efx_nic *efx) {}
 static inline void efx_fini_mcdi_logging(struct efx_nic *efx) {}
 #endif
 
-void efx_mac_reconfigure(struct efx_nic *efx);
+void efx_mac_reconfigure(struct efx_nic *efx, bool mtu_only);
 int efx_set_mac_address(struct net_device *net_dev, void *data);
 void efx_set_rx_mode(struct net_device *net_dev);
 int efx_set_features(struct net_device *net_dev, netdev_features_t data);

drivers/net/ethernet/sfc/ethtool_common.c

@@ -241,7 +241,7 @@ int efx_ethtool_set_pauseparam(struct net_device *net_dev,
 	/* Reconfigure the MAC. The PHY *may* generate a link state change event
 	 * if the user just changed the advertised capabilities, but there's no
 	 * harm doing this twice */
-	efx_mac_reconfigure(efx);
+	efx_mac_reconfigure(efx, false);
 
 out:
 	mutex_unlock(&efx->mac_lock);

drivers/net/ethernet/sfc/net_driver.h

@@ -1356,7 +1356,7 @@ struct efx_nic_type {
 	void (*push_irq_moderation)(struct efx_channel *channel);
 	int (*reconfigure_port)(struct efx_nic *efx);
 	void (*prepare_enable_fc_tx)(struct efx_nic *efx);
-	int (*reconfigure_mac)(struct efx_nic *efx);
+	int (*reconfigure_mac)(struct efx_nic *efx, bool mtu_only);
 	bool (*check_mac_fault)(struct efx_nic *efx);
 	void (*get_wol)(struct efx_nic *efx, struct ethtool_wolinfo *wol);
 	int (*set_wol)(struct efx_nic *efx, u32 type);

drivers/net/ethernet/sfc/siena.c

@@ -633,7 +633,7 @@ static size_t siena_update_nic_stats(struct efx_nic *efx, u64 *full_stats,
 	return SIENA_STAT_COUNT;
 }
 
-static int siena_mac_reconfigure(struct efx_nic *efx)
+static int siena_mac_reconfigure(struct efx_nic *efx, bool mtu_only __always_unused)
 {
 	MCDI_DECLARE_BUF(inbuf, MC_CMD_SET_MCAST_HASH_IN_LEN);
 	int rc;