net: lan966x: Add offload support for mqprio

Implement mqprio qdisc support using tc command.
The HW supports 8 priority queues from highest (7) to lowest (0).

Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/microchip/lan966x/Makefile

@@ -8,4 +8,5 @@ obj-$(CONFIG_LAN966X_SWITCH) += lan966x-switch.o
 lan966x-switch-objs  := lan966x_main.o lan966x_phylink.o lan966x_port.o \
 			lan966x_mac.o lan966x_ethtool.o lan966x_switchdev.o \
 			lan966x_vlan.o lan966x_fdb.o lan966x_mdb.o \
-			lan966x_ptp.o lan966x_fdma.o lan966x_lag.o
+			lan966x_ptp.o lan966x_fdma.o lan966x_lag.o \
+			lan966x_tc.o lan966x_mqprio.o

drivers/net/ethernet/microchip/lan966x/lan966x_main.c

@@ -466,6 +466,7 @@ static const struct net_device_ops lan966x_port_netdev_ops = {
 	.ndo_set_mac_address		= lan966x_port_set_mac_address,
 	.ndo_get_port_parent_id		= lan966x_port_get_parent_id,
 	.ndo_eth_ioctl			= lan966x_port_ioctl,
+	.ndo_setup_tc			= lan966x_tc_setup,
 };
 
 bool lan966x_netdevice_check(const struct net_device *dev)
@@ -755,7 +756,9 @@ static int lan966x_probe_port(struct lan966x *lan966x, u32 p,
 	dev->netdev_ops = &lan966x_port_netdev_ops;
 	dev->ethtool_ops = &lan966x_ethtool_ops;
 	dev->features |= NETIF_F_HW_VLAN_CTAG_TX |
-			 NETIF_F_HW_VLAN_STAG_TX;
+			 NETIF_F_HW_VLAN_STAG_TX |
+			 NETIF_F_HW_TC;
+	dev->hw_features |= NETIF_F_HW_TC;
 	dev->needed_headroom = IFH_LEN * sizeof(u32);
 
 	eth_hw_addr_gen(dev, lan966x->base_mac, p + 1);

drivers/net/ethernet/microchip/lan966x/lan966x_main.h

@@ -446,6 +446,12 @@ void lan966x_port_ageing_set(struct lan966x_port *port,
 			     unsigned long ageing_clock_t);
 void lan966x_update_fwd_mask(struct lan966x *lan966x);
 
+int lan966x_tc_setup(struct net_device *dev, enum tc_setup_type type,
+		     void *type_data);
+
+int lan966x_mqprio_add(struct lan966x_port *port, u8 num_tc);
+int lan966x_mqprio_del(struct lan966x_port *port);
+
 static inline void __iomem *lan_addr(void __iomem *base[],
 				     int id, int tinst, int tcnt,
 				     int gbase, int ginst,

drivers/net/ethernet/microchip/lan966x/lan966x_mqprio.c

@@ -0,0 +1,28 @@
+// SPDX-License-Identifier: GPL-2.0+
+
+#include "lan966x_main.h"
+
+int lan966x_mqprio_add(struct lan966x_port *port, u8 num_tc)
+{
+	u8 i;
+
+	if (num_tc != NUM_PRIO_QUEUES) {
+		netdev_err(port->dev, "Only %d tarffic classes supported\n",
+			   NUM_PRIO_QUEUES);
+		return -EINVAL;
+	}
+
+	netdev_set_num_tc(port->dev, num_tc);
+
+	for (i = 0; i < num_tc; ++i)
+		netdev_set_tc_queue(port->dev, i, 1, i);
+
+	return 0;
+}
+
+int lan966x_mqprio_del(struct lan966x_port *port)
+{
+	netdev_reset_tc(port->dev);
+
+	return 0;
+}

drivers/net/ethernet/microchip/lan966x/lan966x_tc.c

@@ -0,0 +1,31 @@
+// SPDX-License-Identifier: GPL-2.0+
+
+#include <net/pkt_cls.h>
+
+#include "lan966x_main.h"
+
+static int lan966x_tc_setup_qdisc_mqprio(struct lan966x_port *port,
+					 struct tc_mqprio_qopt_offload *mqprio)
+{
+	u8 num_tc = mqprio->qopt.num_tc;
+
+	mqprio->qopt.hw = TC_MQPRIO_HW_OFFLOAD_TCS;
+
+	return num_tc ? lan966x_mqprio_add(port, num_tc) :
+			lan966x_mqprio_del(port);
+}
+
+int lan966x_tc_setup(struct net_device *dev, enum tc_setup_type type,
+		     void *type_data)
+{
+	struct lan966x_port *port = netdev_priv(dev);
+
+	switch (type) {
+	case TC_SETUP_QDISC_MQPRIO:
+		return lan966x_tc_setup_qdisc_mqprio(port, type_data);
+	default:
+		return -EOPNOTSUPP;
+	}
+
+	return 0;
+}