net: ti: am65-cpsw-nuss: Add switchdev support

J721e, J7200 and AM64 have multi port switches which can work in multi
mac mode and in switch mode. Add support for configuring this HW in
switch mode using devlink and switchdev notifiers.

Support is similar to existing CPSW switchdev implementation of TI's 32 bit
platform like AM33/AM43/AM57.

To enable switch mode:
devlink dev param set platform/8000000.ethernet name switch_mode value true cmode runtime

All configuration is implemented via switchdev API and notifiers.
Supported:
      - SWITCHDEV_ATTR_ID_PORT_PRE_BRIDGE_FLAGS
      - SWITCHDEV_ATTR_ID_PORT_BRIDGE_FLAGS
      - SWITCHDEV_ATTR_ID_PORT_STP_STATE
      - SWITCHDEV_OBJ_ID_PORT_VLAN
      - SWITCHDEV_OBJ_ID_PORT_MDB
      - SWITCHDEV_OBJ_ID_HOST_MDB

Hence AM65 CPSW switchdev driver supports:
     - FDB offloading
     - MDB offloading
     - VLAN filtering and offloading
     - STP
Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/ti/Makefile

@@ -26,4 +26,5 @@ keystone_netcp_ethss-y := netcp_ethss.o netcp_sgmii.o netcp_xgbepcsr.o cpsw_ale.
 
 obj-$(CONFIG_TI_K3_AM65_CPSW_NUSS) += ti-am65-cpsw-nuss.o
 ti-am65-cpsw-nuss-y := am65-cpsw-nuss.o cpsw_sl.o am65-cpsw-ethtool.o cpsw_ale.o k3-cppi-desc-pool.o am65-cpsw-qos.o
+ti-am65-cpsw-nuss-$(CONFIG_TI_K3_AM65_CPSW_SWITCHDEV) += am65-cpsw-switchdev.o
 obj-$(CONFIG_TI_K3_AM65_CPTS) += am65-cpts.o

drivers/net/ethernet/ti/am65-cpsw-nuss.c

@@ -31,6 +31,7 @@
 #include "cpsw_ale.h"
 #include "cpsw_sl.h"
 #include "am65-cpsw-nuss.h"
+#include "am65-cpsw-switchdev.h"
 #include "k3-cppi-desc-pool.h"
 #include "am65-cpts.h"
 
@@ -228,6 +229,9 @@ static int am65_cpsw_nuss_ndo_slave_add_vid(struct net_device *ndev,
 	u32 port_mask, unreg_mcast = 0;
 	int ret;
 
+	if (!common->is_emac_mode)
+		return 0;
+
 	if (!netif_running(ndev) || !vid)
 		return 0;
 
@@ -255,6 +259,9 @@ static int am65_cpsw_nuss_ndo_slave_kill_vid(struct net_device *ndev,
 	struct am65_cpsw_port *port = am65_ndev_to_port(ndev);
 	int ret;
 
+	if (!common->is_emac_mode)
+		return 0;
+
 	if (!netif_running(ndev) || !vid)
 		return 0;
 
@@ -277,6 +284,11 @@ static void am65_cpsw_slave_set_promisc(struct am65_cpsw_port *port,
 {
 	struct am65_cpsw_common *common = port->common;
 
+	if (promisc && !common->is_emac_mode) {
+		dev_dbg(common->dev, "promisc mode requested in switch mode");
+		return;
+	}
+
 	if (promisc) {
 		/* Enable promiscuous mode */
 		cpsw_ale_control_set(common->ale, port->port_id,
@@ -800,12 +812,13 @@ static int am65_cpsw_nuss_rx_packets(struct am65_cpsw_common *common,
 
 	new_skb = netdev_alloc_skb_ip_align(ndev, AM65_CPSW_MAX_PACKET_SIZE);
 	if (new_skb) {
+		ndev_priv = netdev_priv(ndev);
+		am65_cpsw_nuss_set_offload_fwd_mark(skb, ndev_priv->offload_fwd_mark);
 		skb_put(skb, pkt_len);
 		skb->protocol = eth_type_trans(skb, ndev);
 		am65_cpsw_nuss_rx_csum(skb, csum_info);
 		napi_gro_receive(&common->napi_rx, skb);
 
-		ndev_priv = netdev_priv(ndev);
 		stats = this_cpu_ptr(ndev_priv->stats);
 
 		u64_stats_update_begin(&stats->syncp);
@@ -2144,6 +2157,10 @@ static int am65_cpsw_register_notifiers(struct am65_cpsw_common *cpsw)
 		return ret;
 	}
 
+	ret = am65_cpsw_switchdev_register_notifiers(cpsw);
+	if (ret)
+		unregister_netdevice_notifier(&cpsw->am65_cpsw_netdevice_nb);
+
 	return ret;
 }
 
@@ -2153,6 +2170,7 @@ static void am65_cpsw_unregister_notifiers(struct am65_cpsw_common *cpsw)
 	    !IS_REACHABLE(CONFIG_TI_K3_AM65_CPSW_SWITCHDEV))
 		return;
 
+	am65_cpsw_switchdev_unregister_notifiers(cpsw);
 	unregister_netdevice_notifier(&cpsw->am65_cpsw_netdevice_nb);
 }
 

drivers/net/ethernet/ti/am65-cpsw-switchdev.h

+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (C) 2020 Texas Instruments Incorporated - https://www.ti.com/
+ */
+
+#ifndef DRIVERS_NET_ETHERNET_TI_AM65_CPSW_SWITCHDEV_H_
+#define DRIVERS_NET_ETHERNET_TI_AM65_CPSW_SWITCHDEV_H_
+
+#include <linux/skbuff.h>
+
+#if IS_ENABLED(CONFIG_TI_K3_AM65_CPSW_SWITCHDEV)
+static inline void am65_cpsw_nuss_set_offload_fwd_mark(struct sk_buff *skb, bool val)
+{
+	skb->offload_fwd_mark = val;
+}
+
+int am65_cpsw_switchdev_register_notifiers(struct am65_cpsw_common *cpsw);
+void am65_cpsw_switchdev_unregister_notifiers(struct am65_cpsw_common *cpsw);
+#else
+static inline int am65_cpsw_switchdev_register_notifiers(struct am65_cpsw_common *cpsw)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline void am65_cpsw_switchdev_unregister_notifiers(struct am65_cpsw_common *cpsw)
+{
+}
+
+static inline void am65_cpsw_nuss_set_offload_fwd_mark(struct sk_buff *skb, bool val)
+{
+}
+
+#endif
+
+#endif /* DRIVERS_NET_ETHERNET_TI_AM65_CPSW_SWITCHDEV_H_ */