[PATCH net-next v3 3/4] net: dsa: add support for offloading HSR

[George McCollister <george.mccollister@gmail.com>]

Add support for offloading of HSR/PRP (IEC 62439-3) tag insertion
tag removal, duplicate generation and forwarding on DSA switches.

Add DSA_NOTIFIER_HSR_JOIN and DSA_NOTIFIER_HSR_LEAVE which trigger calls
to .port_hsr_join and .port_hsr_leave in the DSA driver for the switch.

The DSA switch driver should then set netdev feature flags for the
HSR/PRP operation that it offloads.
    NETIF_F_HW_HSR_TAG_INS
    NETIF_F_HW_HSR_TAG_RM
    NETIF_F_HW_HSR_FWD
    NETIF_F_HW_HSR_DUP

Signed-off-by: George McCollister <george.mccollister@gmail.com>
---
 include/net/dsa.h  | 13 +++++++++++++
 net/dsa/dsa_priv.h | 11 +++++++++++
 net/dsa/port.c     | 34 ++++++++++++++++++++++++++++++++++
 net/dsa/slave.c    | 14 ++++++++++++++
 net/dsa/switch.c   | 24 ++++++++++++++++++++++++
 5 files changed, 96 insertions(+)

diff --git a/include/net/dsa.h b/include/net/dsa.h
index 60acb9fca124..d8de23ce7221 100644
--- a/include/net/dsa.h
+++ b/include/net/dsa.h
@@ -172,6 +172,10 @@ struct dsa_switch_tree {
 	list_for_each_entry((_dp), &(_dst)->ports, list)	\
 		if ((_dp)->lag_dev == (_lag))
 
+#define dsa_hsr_foreach_port(_dp, _ds, _hsr)			\
+	list_for_each_entry((_dp), &(_ds)->dst->ports, list)	\
+		if ((_dp)->ds == (_ds) && (_dp)->hsr_dev == (_hsr))
+
 static inline struct net_device *dsa_lag_dev(struct dsa_switch_tree *dst,
 					     unsigned int id)
 {
@@ -264,6 +268,7 @@ struct dsa_port {
 	struct phylink_config	pl_config;
 	struct net_device	*lag_dev;
 	bool			lag_tx_enabled;
+	struct net_device	*hsr_dev;
 
 	struct list_head list;
 
@@ -769,6 +774,14 @@ struct dsa_switch_ops {
 				 struct netdev_lag_upper_info *info);
 	int	(*port_lag_leave)(struct dsa_switch *ds, int port,
 				  struct net_device *lag);
+
+	/*
+	 * HSR integration
+	 */
+	int	(*port_hsr_join)(struct dsa_switch *ds, int port,
+				 struct net_device *hsr);
+	int	(*port_hsr_leave)(struct dsa_switch *ds, int port,
+				  struct net_device *hsr);
 };
 
 #define DSA_DEVLINK_PARAM_DRIVER(_id, _name, _type, _cmodes)		\
diff --git a/net/dsa/dsa_priv.h b/net/dsa/dsa_priv.h
index 263593ce94a8..bb41f8bf4f6e 100644
--- a/net/dsa/dsa_priv.h
+++ b/net/dsa/dsa_priv.h
@@ -20,6 +20,8 @@ enum {
 	DSA_NOTIFIER_BRIDGE_LEAVE,
 	DSA_NOTIFIER_FDB_ADD,
 	DSA_NOTIFIER_FDB_DEL,
+	DSA_NOTIFIER_HSR_JOIN,
+	DSA_NOTIFIER_HSR_LEAVE,
 	DSA_NOTIFIER_LAG_CHANGE,
 	DSA_NOTIFIER_LAG_JOIN,
 	DSA_NOTIFIER_LAG_LEAVE,
@@ -100,6 +102,13 @@ struct dsa_switchdev_event_work {
 	u16 vid;
 };
 
+/* DSA_NOTIFIER_HSR_* */
+struct dsa_notifier_hsr_info {
+	struct net_device *hsr;
+	int sw_index;
+	int port;
+};
+
 struct dsa_slave_priv {
 	/* Copy of CPU port xmit for faster access in slave transmit hot path */
 	struct sk_buff *	(*xmit)(struct sk_buff *skb,
@@ -183,6 +192,8 @@ int dsa_port_vlan_del(struct dsa_port *dp,
 		      const struct switchdev_obj_port_vlan *vlan);
 int dsa_port_link_register_of(struct dsa_port *dp);
 void dsa_port_link_unregister_of(struct dsa_port *dp);
+int dsa_port_hsr_join(struct dsa_port *dp, struct net_device *hsr);
+void dsa_port_hsr_leave(struct dsa_port *dp, struct net_device *hsr);
 extern const struct phylink_mac_ops dsa_port_phylink_mac_ops;
 
 static inline bool dsa_port_offloads_netdev(struct dsa_port *dp,
diff --git a/net/dsa/port.c b/net/dsa/port.c
index 5e079a61528e..b93bda463026 100644
--- a/net/dsa/port.c
+++ b/net/dsa/port.c
@@ -868,3 +868,37 @@ int dsa_port_get_phy_sset_count(struct dsa_port *dp)
 	return ret;
 }
 EXPORT_SYMBOL_GPL(dsa_port_get_phy_sset_count);
+
+int dsa_port_hsr_join(struct dsa_port *dp, struct net_device *hsr)
+{
+	struct dsa_notifier_hsr_info info = {
+		.sw_index = dp->ds->index,
+		.port = dp->index,
+		.hsr = hsr,
+	};
+	int err;
+
+	dp->hsr_dev = hsr;
+
+	err = dsa_port_notify(dp, DSA_NOTIFIER_HSR_JOIN, &info);
+	if (err)
+		dp->hsr_dev = NULL;
+
+	return err;
+}
+
+void dsa_port_hsr_leave(struct dsa_port *dp, struct net_device *hsr)
+{
+	struct dsa_notifier_hsr_info info = {
+		.sw_index = dp->ds->index,
+		.port = dp->index,
+		.hsr = hsr,
+	};
+	int err;
+
+	dp->hsr_dev = NULL;
+
+	err = dsa_port_notify(dp, DSA_NOTIFIER_HSR_LEAVE, &info);
+	if (err)
+		pr_err("DSA: failed to notify DSA_NOTIFIER_HSR_LEAVE\n");
+}
diff --git a/net/dsa/slave.c b/net/dsa/slave.c
index b0571ab4e5a7..11d01276f11d 100644
--- a/net/dsa/slave.c
+++ b/net/dsa/slave.c
@@ -17,6 +17,7 @@
 #include <net/pkt_cls.h>
 #include <net/tc_act/tc_mirred.h>
 #include <linux/if_bridge.h>
+#include <linux/if_hsr.h>
 #include <linux/netpoll.h>
 #include <linux/ptp_classify.h>
 
@@ -1935,6 +1936,19 @@ static int dsa_slave_changeupper(struct net_device *dev,
 			dsa_port_lag_leave(dp, info->upper_dev);
 			err = NOTIFY_OK;
 		}
+	} else if (is_hsr_master(info->upper_dev)) {
+		if (info->linking) {
+			err = dsa_port_hsr_join(dp, info->upper_dev);
+			if (err == -EOPNOTSUPP) {
+				NL_SET_ERR_MSG_MOD(info->info.extack,
+						   "Offloading not supported");
+				err = 0;
+			}
+			err = notifier_from_errno(err);
+		} else {
+			dsa_port_hsr_leave(dp, info->upper_dev);
+			err = NOTIFY_OK;
+		}
 	}
 
 	return err;
diff --git a/net/dsa/switch.c b/net/dsa/switch.c
index 5026e4143663..1906179e59f7 100644
--- a/net/dsa/switch.c
+++ b/net/dsa/switch.c
@@ -166,6 +166,24 @@ static int dsa_switch_fdb_del(struct dsa_switch *ds,
 	return ds->ops->port_fdb_del(ds, port, info->addr, info->vid);
 }
 
+static int dsa_switch_hsr_join(struct dsa_switch *ds,
+			       struct dsa_notifier_hsr_info *info)
+{
+	if (ds->index == info->sw_index && ds->ops->port_hsr_join)
+		return ds->ops->port_hsr_join(ds, info->port, info->hsr);
+
+	return -EOPNOTSUPP;
+}
+
+static int dsa_switch_hsr_leave(struct dsa_switch *ds,
+				struct dsa_notifier_hsr_info *info)
+{
+	if (ds->index == info->sw_index && ds->ops->port_hsr_leave)
+		return ds->ops->port_hsr_leave(ds, info->port, info->hsr);
+
+	return -EOPNOTSUPP;
+}
+
 static int dsa_switch_lag_change(struct dsa_switch *ds,
 				 struct dsa_notifier_lag_info *info)
 {
@@ -371,6 +389,12 @@ static int dsa_switch_event(struct notifier_block *nb,
 	case DSA_NOTIFIER_FDB_DEL:
 		err = dsa_switch_fdb_del(ds, info);
 		break;
+	case DSA_NOTIFIER_HSR_JOIN:
+		err = dsa_switch_hsr_join(ds, info);
+		break;
+	case DSA_NOTIFIER_HSR_LEAVE:
+		err = dsa_switch_hsr_leave(ds, info);
+		break;
 	case DSA_NOTIFIER_LAG_CHANGE:
 		err = dsa_switch_lag_change(ds, info);
 		break;
-- 
2.11.0