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From:   Horatiu Vultur <horatiu.vultur@microchip.com>
To:     <netdev@vger.kernel.org>, <devicetree@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>
CC:     <davem@davemloft.net>, <kuba@kernel.org>, <robh+dt@kernel.org>,
        <UNGLinuxDriver@microchip.com>, <linux@armlinux.org.uk>,
        <f.fainelli@gmail.com>, <vivien.didelot@gmail.com>,
        <vladimir.oltean@nxp.com>, <andrew@lunn.ch>,
        Horatiu Vultur <horatiu.vultur@microchip.com>
Subject: [PATCH net-next v7 6/9] net: lan966x: Add support to offload the forwarding.
Date:   Fri, 17 Dec 2021 16:53:50 +0100
Message-ID: <20211217155353.460594-7-horatiu.vultur@microchip.com>
In-Reply-To: <20211217155353.460594-1-horatiu.vultur@microchip.com>
References: <20211217155353.460594-1-horatiu.vultur@microchip.com>
MIME-Version: 1.0
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Precedence: bulk

This patch adds basic support to offload in the HW the forwarding of the
frames. The driver registers to the switchdev callbacks and implements
the callbacks for attributes SWITCHDEV_ATTR_ID_PORT_STP_STATE and
SWITCHDEV_ATTR_ID_BRIDGE_AGEING_TIME.
It is not allowed to add a lan966x port to a bridge that contains a
different interface than lan966x.

Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
---
 .../net/ethernet/microchip/lan966x/Kconfig    |   1 +
 .../net/ethernet/microchip/lan966x/Makefile   |   2 +-
 .../ethernet/microchip/lan966x/lan966x_main.c |  32 +-
 .../ethernet/microchip/lan966x/lan966x_main.h |   9 +
 .../microchip/lan966x/lan966x_switchdev.c     | 309 ++++++++++++++++++
 5 files changed, 351 insertions(+), 2 deletions(-)
 create mode 100644 drivers/net/ethernet/microchip/lan966x/lan966x_switchdev.c

diff --git a/drivers/net/ethernet/microchip/lan966x/Kconfig b/drivers/net/ethernet/microchip/lan966x/Kconfig
index 2860a8c9923d..ac273f84b69e 100644
--- a/drivers/net/ethernet/microchip/lan966x/Kconfig
+++ b/drivers/net/ethernet/microchip/lan966x/Kconfig
@@ -2,6 +2,7 @@ config LAN966X_SWITCH
 	tristate "Lan966x switch driver"
 	depends on HAS_IOMEM
 	depends on OF
+	depends on NET_SWITCHDEV
 	select PHYLINK
 	select PACKING
 	help
diff --git a/drivers/net/ethernet/microchip/lan966x/Makefile b/drivers/net/ethernet/microchip/lan966x/Makefile
index 2989ba528236..974229c51f55 100644
--- a/drivers/net/ethernet/microchip/lan966x/Makefile
+++ b/drivers/net/ethernet/microchip/lan966x/Makefile
@@ -6,4 +6,4 @@
 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_mac.o lan966x_ethtool.o lan966x_switchdev.o
diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_main.c b/drivers/net/ethernet/microchip/lan966x/lan966x_main.c
index dc40ac2eb246..5af60234d81d 100644
--- a/drivers/net/ethernet/microchip/lan966x/lan966x_main.c
+++ b/drivers/net/ethernet/microchip/lan966x/lan966x_main.c
@@ -355,6 +355,11 @@ static const struct net_device_ops lan966x_port_netdev_ops = {
 	.ndo_get_port_parent_id		= lan966x_port_get_parent_id,
 };
 
+bool lan966x_netdevice_check(const struct net_device *dev)
+{
+	return dev->netdev_ops == &lan966x_port_netdev_ops;
+}
+
 static int lan966x_port_xtr_status(struct lan966x *lan966x, u8 grp)
 {
 	return lan_rd(lan966x, QS_XTR_RD(grp));
@@ -491,6 +496,9 @@ static irqreturn_t lan966x_xtr_irq_handler(int irq, void *args)
 
 		skb->protocol = eth_type_trans(skb, dev);
 
+		if (lan966x->bridge_mask & BIT(src_port))
+			skb->offload_fwd_mark = 1;
+
 		netif_rx_ni(skb);
 		dev->stats.rx_bytes += len;
 		dev->stats.rx_packets++;
@@ -915,6 +923,7 @@ static int lan966x_remove(struct platform_device *pdev)
 {
 	struct lan966x *lan966x = platform_get_drvdata(pdev);
 
+	lan966x_unregister_notifier_blocks();
 	lan966x_cleanup_ports(lan966x);
 
 	cancel_delayed_work_sync(&lan966x->stats_work);
@@ -934,7 +943,28 @@ static struct platform_driver lan966x_driver = {
 		.of_match_table = lan966x_match,
 	},
 };
-module_platform_driver(lan966x_driver);
+
+static int __init lan966x_switch_driver_init(void)
+{
+	int ret;
+
+	ret = platform_driver_register(&lan966x_driver);
+	if (ret)
+		return ret;
+
+	lan966x_register_notifier_blocks();
+
+	return 0;
+}
+
+static void __exit lan966x_switch_driver_exit(void)
+{
+	lan966x_unregister_notifier_blocks();
+	platform_driver_unregister(&lan966x_driver);
+}
+
+module_init(lan966x_switch_driver_init);
+module_exit(lan966x_switch_driver_exit);
 
 MODULE_DESCRIPTION("Microchip LAN966X switch driver");
 MODULE_AUTHOR("Horatiu Vultur <horatiu.vultur@microchip.com>");
diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_main.h b/drivers/net/ethernet/microchip/lan966x/lan966x_main.h
index fcd5d09a070c..4723a904c13e 100644
--- a/drivers/net/ethernet/microchip/lan966x/lan966x_main.h
+++ b/drivers/net/ethernet/microchip/lan966x/lan966x_main.h
@@ -75,6 +75,10 @@ struct lan966x {
 
 	u8 base_mac[ETH_ALEN];
 
+	struct net_device *bridge;
+	u16 bridge_mask;
+	u16 bridge_fwd_mask;
+
 	struct list_head mac_entries;
 	spinlock_t mac_lock; /* lock for mac_entries list */
 
@@ -122,6 +126,11 @@ extern const struct phylink_mac_ops lan966x_phylink_mac_ops;
 extern const struct phylink_pcs_ops lan966x_phylink_pcs_ops;
 extern const struct ethtool_ops lan966x_ethtool_ops;
 
+bool lan966x_netdevice_check(const struct net_device *dev);
+
+void lan966x_register_notifier_blocks(void);
+void lan966x_unregister_notifier_blocks(void);
+
 void lan966x_stats_get(struct net_device *dev,
 		       struct rtnl_link_stats64 *stats);
 int lan966x_stats_init(struct lan966x *lan966x);
diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_switchdev.c b/drivers/net/ethernet/microchip/lan966x/lan966x_switchdev.c
new file mode 100644
index 000000000000..9db17b677357
--- /dev/null
+++ b/drivers/net/ethernet/microchip/lan966x/lan966x_switchdev.c
@@ -0,0 +1,309 @@
+// SPDX-License-Identifier: GPL-2.0+
+
+#include <linux/if_bridge.h>
+#include <net/switchdev.h>
+
+#include "lan966x_main.h"
+
+static struct notifier_block lan966x_netdevice_nb __read_mostly;
+static struct notifier_block lan966x_switchdev_nb __read_mostly;
+static struct notifier_block lan966x_switchdev_blocking_nb __read_mostly;
+
+static void lan966x_update_fwd_mask(struct lan966x *lan966x)
+{
+	int i;
+
+	for (i = 0; i < lan966x->num_phys_ports; i++) {
+		struct lan966x_port *port = lan966x->ports[i];
+		unsigned long mask = 0;
+
+		if (port && lan966x->bridge_fwd_mask & BIT(i))
+			mask = lan966x->bridge_fwd_mask & ~BIT(i);
+
+		mask |= BIT(CPU_PORT);
+
+		lan_wr(ANA_PGID_PGID_SET(mask),
+		       lan966x, ANA_PGID(PGID_SRC + i));
+	}
+}
+
+static void lan966x_port_stp_state_set(struct lan966x_port *port, u8 state)
+{
+	struct lan966x *lan966x = port->lan966x;
+	bool learn_ena = false;
+
+	if (state == BR_STATE_FORWARDING || state == BR_STATE_LEARNING)
+		learn_ena = true;
+
+	if (state == BR_STATE_FORWARDING)
+		lan966x->bridge_fwd_mask |= BIT(port->chip_port);
+	else
+		lan966x->bridge_fwd_mask &= ~BIT(port->chip_port);
+
+	lan_rmw(ANA_PORT_CFG_LEARN_ENA_SET(learn_ena),
+		ANA_PORT_CFG_LEARN_ENA,
+		lan966x, ANA_PORT_CFG(port->chip_port));
+
+	lan966x_update_fwd_mask(lan966x);
+}
+
+static void lan966x_port_ageing_set(struct lan966x_port *port,
+				    unsigned long ageing_clock_t)
+{
+	unsigned long ageing_jiffies = clock_t_to_jiffies(ageing_clock_t);
+	u32 ageing_time = jiffies_to_msecs(ageing_jiffies) / 1000;
+
+	lan966x_mac_set_ageing(port->lan966x, ageing_time);
+}
+
+static int lan966x_port_attr_set(struct net_device *dev, const void *ctx,
+				 const struct switchdev_attr *attr,
+				 struct netlink_ext_ack *extack)
+{
+	struct lan966x_port *port = netdev_priv(dev);
+	int err = 0;
+
+	if (ctx && ctx != port)
+		return 0;
+
+	switch (attr->id) {
+	case SWITCHDEV_ATTR_ID_PORT_STP_STATE:
+		lan966x_port_stp_state_set(port, attr->u.stp_state);
+		break;
+	case SWITCHDEV_ATTR_ID_BRIDGE_AGEING_TIME:
+		lan966x_port_ageing_set(port, attr->u.ageing_time);
+		break;
+	default:
+		err = -EOPNOTSUPP;
+		break;
+	}
+
+	return err;
+}
+
+static int lan966x_port_bridge_join(struct lan966x_port *port,
+				    struct net_device *bridge,
+				    struct netlink_ext_ack *extack)
+{
+	struct lan966x *lan966x = port->lan966x;
+	struct net_device *dev = port->dev;
+	int err;
+
+	if (!lan966x->bridge_mask) {
+		lan966x->bridge = bridge;
+	} else {
+		if (lan966x->bridge != bridge) {
+			NL_SET_ERR_MSG_MOD(extack, "Not allow to add port to different bridge");
+			return -ENODEV;
+		}
+	}
+
+	err = switchdev_bridge_port_offload(dev, dev, port,
+					    &lan966x_switchdev_nb,
+					    &lan966x_switchdev_blocking_nb,
+					    false, extack);
+	if (err)
+		return err;
+
+	lan966x->bridge_mask |= BIT(port->chip_port);
+
+	return 0;
+}
+
+static void lan966x_port_bridge_leave(struct lan966x_port *port,
+				      struct net_device *bridge)
+{
+	struct lan966x *lan966x = port->lan966x;
+
+	lan966x->bridge_mask &= ~BIT(port->chip_port);
+
+	if (!lan966x->bridge_mask)
+		lan966x->bridge = NULL;
+
+	lan966x_mac_cpu_learn(lan966x, port->dev->dev_addr, PORT_PVID);
+}
+
+static int lan966x_port_changeupper(struct net_device *dev,
+				    struct netdev_notifier_changeupper_info *info)
+{
+	struct lan966x_port *port = netdev_priv(dev);
+	struct netlink_ext_ack *extack;
+	int err = 0;
+
+	extack = netdev_notifier_info_to_extack(&info->info);
+
+	if (netif_is_bridge_master(info->upper_dev)) {
+		if (info->linking)
+			err = lan966x_port_bridge_join(port, info->upper_dev,
+						       extack);
+		else
+			lan966x_port_bridge_leave(port, info->upper_dev);
+	}
+
+	return err;
+}
+
+static int lan966x_port_prechangeupper(struct net_device *dev,
+				       struct netdev_notifier_changeupper_info *info)
+{
+	struct lan966x_port *port = netdev_priv(dev);
+
+	if (netif_is_bridge_master(info->upper_dev) && !info->linking)
+		switchdev_bridge_port_unoffload(port->dev, port,
+						&lan966x_switchdev_nb,
+						&lan966x_switchdev_blocking_nb);
+
+	return NOTIFY_DONE;
+}
+
+static int lan966x_foreign_bridging_check(struct net_device *bridge,
+					  struct netlink_ext_ack *extack)
+{
+	struct lan966x *lan966x = NULL;
+	bool has_foreign = false;
+	struct net_device *dev;
+	struct list_head *iter;
+
+	if (!netif_is_bridge_master(bridge))
+		return 0;
+
+	netdev_for_each_lower_dev(bridge, dev, iter) {
+		if (lan966x_netdevice_check(dev)) {
+			struct lan966x_port *port = netdev_priv(dev);
+
+			if (lan966x) {
+				/* Bridge already has at least one port of a
+				 * lan966x switch inside it, check that it's
+				 * the same instance of the driver.
+				 */
+				if (port->lan966x != lan966x) {
+					NL_SET_ERR_MSG_MOD(extack,
+							   "Bridging between multiple lan966x switches disallowed");
+					return -EINVAL;
+				}
+			} else {
+				/* This is the first lan966x port inside this
+				 * bridge
+				 */
+				lan966x = port->lan966x;
+			}
+		} else {
+			has_foreign = true;
+		}
+
+		if (lan966x && has_foreign) {
+			NL_SET_ERR_MSG_MOD(extack,
+					   "Bridging lan966x ports with foreign interfaces disallowed");
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
+static int lan966x_bridge_check(struct net_device *dev,
+				struct netdev_notifier_changeupper_info *info)
+{
+	return lan966x_foreign_bridging_check(info->upper_dev,
+					      info->info.extack);
+}
+
+static int lan966x_netdevice_port_event(struct net_device *dev,
+					struct notifier_block *nb,
+					unsigned long event, void *ptr)
+{
+	int err = 0;
+
+	if (!lan966x_netdevice_check(dev)) {
+		if (event == NETDEV_CHANGEUPPER)
+			return lan966x_bridge_check(dev, ptr);
+		return 0;
+	}
+
+	switch (event) {
+	case NETDEV_PRECHANGEUPPER:
+		err = lan966x_port_prechangeupper(dev, ptr);
+		break;
+	case NETDEV_CHANGEUPPER:
+		err = lan966x_bridge_check(dev, ptr);
+		if (err)
+			return err;
+
+		err = lan966x_port_changeupper(dev, ptr);
+		break;
+	}
+
+	return err;
+}
+
+static int lan966x_netdevice_event(struct notifier_block *nb,
+				   unsigned long event, void *ptr)
+{
+	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
+	int ret;
+
+	ret = lan966x_netdevice_port_event(dev, nb, event, ptr);
+
+	return notifier_from_errno(ret);
+}
+
+static int lan966x_switchdev_event(struct notifier_block *nb,
+				   unsigned long event, void *ptr)
+{
+	struct net_device *dev = switchdev_notifier_info_to_dev(ptr);
+	int err;
+
+	switch (event) {
+	case SWITCHDEV_PORT_ATTR_SET:
+		err = switchdev_handle_port_attr_set(dev, ptr,
+						     lan966x_netdevice_check,
+						     lan966x_port_attr_set);
+		return notifier_from_errno(err);
+	}
+
+	return NOTIFY_DONE;
+}
+
+static int lan966x_switchdev_blocking_event(struct notifier_block *nb,
+					    unsigned long event,
+					    void *ptr)
+{
+	struct net_device *dev = switchdev_notifier_info_to_dev(ptr);
+	int err;
+
+	switch (event) {
+	case SWITCHDEV_PORT_ATTR_SET:
+		err = switchdev_handle_port_attr_set(dev, ptr,
+						     lan966x_netdevice_check,
+						     lan966x_port_attr_set);
+		return notifier_from_errno(err);
+	}
+
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block lan966x_netdevice_nb __read_mostly = {
+	.notifier_call = lan966x_netdevice_event,
+};
+
+static struct notifier_block lan966x_switchdev_nb __read_mostly = {
+	.notifier_call = lan966x_switchdev_event,
+};
+
+static struct notifier_block lan966x_switchdev_blocking_nb __read_mostly = {
+	.notifier_call = lan966x_switchdev_blocking_event,
+};
+
+void lan966x_register_notifier_blocks(void)
+{
+	register_netdevice_notifier(&lan966x_netdevice_nb);
+	register_switchdev_notifier(&lan966x_switchdev_nb);
+	register_switchdev_blocking_notifier(&lan966x_switchdev_blocking_nb);
+}
+
+void lan966x_unregister_notifier_blocks(void)
+{
+	unregister_switchdev_blocking_notifier(&lan966x_switchdev_blocking_nb);
+	unregister_switchdev_notifier(&lan966x_switchdev_nb);
+	unregister_netdevice_notifier(&lan966x_netdevice_nb);
+}
-- 
2.33.0