net: microchip: sparx5: add support for offloading mqprio qdisc

Add support for offloading mqprio qdisc to sparx5 switch.

The offloaded mqprio qdisc currently does nothing by itself, but serves
as an attachment point for other qdiscs (tbf, ets etc.)
Signed-off-by: Daniel Machon <daniel.machon@microchip.com>
Signed-off-by: Steen Hegelund <steen.hegelund@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/microchip/sparx5/Makefile

@@ -8,4 +8,4 @@ obj-$(CONFIG_SPARX5_SWITCH) += sparx5-switch.o
 sparx5-switch-objs  := sparx5_main.o sparx5_packet.o \
  sparx5_netdev.o sparx5_phylink.o sparx5_port.o sparx5_mactable.o sparx5_vlan.o \
  sparx5_switchdev.o sparx5_calendar.o sparx5_ethtool.o sparx5_fdma.o \
- sparx5_ptp.o sparx5_pgid.o sparx5_tc.o
+ sparx5_ptp.o sparx5_pgid.o sparx5_tc.o sparx5_qos.o

drivers/net/ethernet/microchip/sparx5/sparx5_netdev.c

@@ -242,10 +242,14 @@ struct net_device *sparx5_create_netdev(struct sparx5 *sparx5, u32 portno)
 	struct sparx5_port *spx5_port;
 	struct net_device *ndev;
 
-	ndev = devm_alloc_etherdev(sparx5->dev, sizeof(struct sparx5_port));
+	ndev = devm_alloc_etherdev_mqs(sparx5->dev, sizeof(struct sparx5_port),
+				       SPX5_PRIOS, 1);
 	if (!ndev)
 		return ERR_PTR(-ENOMEM);
 
+	ndev->hw_features |= NETIF_F_HW_TC;
+	ndev->features |= NETIF_F_HW_TC;
+
 	SET_NETDEV_DEV(ndev, sparx5->dev);
 	spx5_port = netdev_priv(ndev);
 	spx5_port->ndev = ndev;

drivers/net/ethernet/microchip/sparx5/sparx5_qos.c

+// SPDX-License-Identifier: GPL-2.0+
+/* Microchip Sparx5 Switch driver
+ *
+ * Copyright (c) 2022 Microchip Technology Inc. and its subsidiaries.
+ */
+
+#include "sparx5_main.h"
+#include "sparx5_qos.h"
+
+int sparx5_tc_mqprio_add(struct net_device *ndev, u8 num_tc)
+{
+	int i;
+
+	if (num_tc != SPX5_PRIOS) {
+		netdev_err(ndev, "Only %d traffic classes supported\n",
+			   SPX5_PRIOS);
+		return -EINVAL;
+	}
+
+	netdev_set_num_tc(ndev, num_tc);
+
+	for (i = 0; i < num_tc; i++)
+		netdev_set_tc_queue(ndev, i, 1, i);
+
+	netdev_dbg(ndev, "dev->num_tc %u dev->real_num_tx_queues %u\n",
+		   ndev->num_tc, ndev->real_num_tx_queues);
+
+	return 0;
+}
+
+int sparx5_tc_mqprio_del(struct net_device *ndev)
+{
+	netdev_reset_tc(ndev);
+
+	netdev_dbg(ndev, "dev->num_tc %u dev->real_num_tx_queues %u\n",
+		   ndev->num_tc, ndev->real_num_tx_queues);
+
+	return 0;
+}

drivers/net/ethernet/microchip/sparx5/sparx5_qos.h

+/* SPDX-License-Identifier: GPL-2.0+ */
+/* Microchip Sparx5 Switch driver
+ *
+ * Copyright (c) 2022 Microchip Technology Inc. and its subsidiaries.
+ */
+
+#ifndef __SPARX5_QOS_H__
+#define __SPARX5_QOS_H__
+
+#include <linux/netdevice.h>
+
+/* Multi-Queue Priority */
+int sparx5_tc_mqprio_add(struct net_device *ndev, u8 num_tc);
+int sparx5_tc_mqprio_del(struct net_device *ndev);
+
+#endif	/* __SPARX5_QOS_H__ */

drivers/net/ethernet/microchip/sparx5/sparx5_tc.c

@@ -4,13 +4,29 @@
  * Copyright (c) 2022 Microchip Technology Inc. and its subsidiaries.
  */
 
+#include <net/pkt_cls.h>
+
 #include "sparx5_tc.h"
 #include "sparx5_main.h"
+#include "sparx5_qos.h"
+
+static int sparx5_tc_setup_qdisc_mqprio(struct net_device *ndev,
+					struct tc_mqprio_qopt_offload *m)
+{
+	m->qopt.hw = TC_MQPRIO_HW_OFFLOAD_TCS;
+
+	if (m->qopt.num_tc == 0)
+		return sparx5_tc_mqprio_del(ndev);
+	else
+		return sparx5_tc_mqprio_add(ndev, m->qopt.num_tc);
+}
 
 int sparx5_port_setup_tc(struct net_device *ndev, enum tc_setup_type type,
 			 void *type_data)
 {
 	switch (type) {
+	case TC_SETUP_QDISC_MQPRIO:
+		return sparx5_tc_setup_qdisc_mqprio(ndev, type_data);
 	default:
 		return -EOPNOTSUPP;
 	}