net: switchdev: add a context void pointer to struct switchdev_notifier_info

In the case where the driver asks for a replay of a certain type of
event (port object or attribute) for a bridge port that is a LAG, it may
do so because this port has just joined the LAG.

But there might already be other switchdev ports in that LAG, and it is
preferable that those preexisting switchdev ports do not act upon the
replayed event.

The solution is to add a context to switchdev events, which is NULL most
of the time (when the bridge layer initiates the call) but which can be
set to a value controlled by the switchdev driver when a replay is
requested. The driver can then check the context to figure out if all
ports within the LAG should act upon the switchdev event, or just the
ones that match the context.

We have to modify all switchdev_handle_* helper functions as well as the
prototypes in the drivers that use these helpers too, because these
helpers hide the underlying struct switchdev_notifier_info from us and
there is no way to retrieve the context otherwise.

The context structure will be populated and used in later patches.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 17 insertions, 14 deletions

diff --git a/net/dsa/slave.c b/net/dsa/slave.c
index 5e668e529575..3692259a025f 100644
--- a/net/dsa/slave.c
+++ b/net/dsa/slave.c
@@ -271,7 +271,7 @@ static int dsa_slave_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
 	return phylink_mii_ioctl(p->dp->pl, ifr, cmd);
 }
 
-static int dsa_slave_port_attr_set(struct net_device *dev,
+static int dsa_slave_port_attr_set(struct net_device *dev, const void *ctx,
 				   const struct switchdev_attr *attr,
 				   struct netlink_ext_ack *extack)
 {
@@ -394,7 +394,7 @@ static int dsa_slave_vlan_add(struct net_device *dev,
 	return vlan_vid_add(master, htons(ETH_P_8021Q), vlan.vid);
 }
 
-static int dsa_slave_port_obj_add(struct net_device *dev,
+static int dsa_slave_port_obj_add(struct net_device *dev, const void *ctx,
 				  const struct switchdev_obj *obj,
 				  struct netlink_ext_ack *extack)
 {
@@ -469,7 +469,7 @@ static int dsa_slave_vlan_del(struct net_device *dev,
 	return 0;
 }
 
-static int dsa_slave_port_obj_del(struct net_device *dev,
+static int dsa_slave_port_obj_del(struct net_device *dev, const void *ctx,
 				  const struct switchdev_obj *obj)
 {
 	struct dsa_port *dp = dsa_slave_to_port(dev);
diff --git a/net/switchdev/switchdev.c b/net/switchdev/switchdev.c
index 89a36db47ab4..070698dd19bc 100644
--- a/net/switchdev/switchdev.c
+++ b/net/switchdev/switchdev.c
@@ -381,19 +381,20 @@ EXPORT_SYMBOL_GPL(call_switchdev_blocking_notifiers);
 static int __switchdev_handle_port_obj_add(struct net_device *dev,
 			struct switchdev_notifier_port_obj_info *port_obj_info,
 			bool (*check_cb)(const struct net_device *dev),
-			int (*add_cb)(struct net_device *dev,
+			int (*add_cb)(struct net_device *dev, const void *ctx,
 				      const struct switchdev_obj *obj,
 				      struct netlink_ext_ack *extack))
 {
+	struct switchdev_notifier_info *info = &port_obj_info->info;
 	struct netlink_ext_ack *extack;
 	struct net_device *lower_dev;
 	struct list_head *iter;
 	int err = -EOPNOTSUPP;
 
-	extack = switchdev_notifier_info_to_extack(&port_obj_info->info);
+	extack = switchdev_notifier_info_to_extack(info);
 
 	if (check_cb(dev)) {
-		err = add_cb(dev, port_obj_info->obj, extack);
+		err = add_cb(dev, info->ctx, port_obj_info->obj, extack);
 		if (err != -EOPNOTSUPP)
 			port_obj_info->handled = true;
 		return err;
@@ -422,7 +423,7 @@ static int __switchdev_handle_port_obj_add(struct net_device *dev,
 int switchdev_handle_port_obj_add(struct net_device *dev,
 			struct switchdev_notifier_port_obj_info *port_obj_info,
 			bool (*check_cb)(const struct net_device *dev),
-			int (*add_cb)(struct net_device *dev,
+			int (*add_cb)(struct net_device *dev, const void *ctx,
 				      const struct switchdev_obj *obj,
 				      struct netlink_ext_ack *extack))
 {
@@ -439,15 +440,16 @@ EXPORT_SYMBOL_GPL(switchdev_handle_port_obj_add);
 static int __switchdev_handle_port_obj_del(struct net_device *dev,
 			struct switchdev_notifier_port_obj_info *port_obj_info,
 			bool (*check_cb)(const struct net_device *dev),
-			int (*del_cb)(struct net_device *dev,
+			int (*del_cb)(struct net_device *dev, const void *ctx,
 				      const struct switchdev_obj *obj))
 {
+	struct switchdev_notifier_info *info = &port_obj_info->info;
 	struct net_device *lower_dev;
 	struct list_head *iter;
 	int err = -EOPNOTSUPP;
 
 	if (check_cb(dev)) {
-		err = del_cb(dev, port_obj_info->obj);
+		err = del_cb(dev, info->ctx, port_obj_info->obj);
 		if (err != -EOPNOTSUPP)
 			port_obj_info->handled = true;
 		return err;
@@ -476,7 +478,7 @@ static int __switchdev_handle_port_obj_del(struct net_device *dev,
 int switchdev_handle_port_obj_del(struct net_device *dev,
 			struct switchdev_notifier_port_obj_info *port_obj_info,
 			bool (*check_cb)(const struct net_device *dev),
-			int (*del_cb)(struct net_device *dev,
+			int (*del_cb)(struct net_device *dev, const void *ctx,
 				      const struct switchdev_obj *obj))
 {
 	int err;
@@ -492,19 +494,20 @@ EXPORT_SYMBOL_GPL(switchdev_handle_port_obj_del);
 static int __switchdev_handle_port_attr_set(struct net_device *dev,
 			struct switchdev_notifier_port_attr_info *port_attr_info,
 			bool (*check_cb)(const struct net_device *dev),
-			int (*set_cb)(struct net_device *dev,
+			int (*set_cb)(struct net_device *dev, const void *ctx,
 				      const struct switchdev_attr *attr,
 				      struct netlink_ext_ack *extack))
 {
+	struct switchdev_notifier_info *info = &port_attr_info->info;
 	struct netlink_ext_ack *extack;
 	struct net_device *lower_dev;
 	struct list_head *iter;
 	int err = -EOPNOTSUPP;
 
-	extack = switchdev_notifier_info_to_extack(&port_attr_info->info);
+	extack = switchdev_notifier_info_to_extack(info);
 
 	if (check_cb(dev)) {
-		err = set_cb(dev, port_attr_info->attr, extack);
+		err = set_cb(dev, info->ctx, port_attr_info->attr, extack);
 		if (err != -EOPNOTSUPP)
 			port_attr_info->handled = true;
 		return err;
@@ -533,7 +536,7 @@ static int __switchdev_handle_port_attr_set(struct net_device *dev,
 int switchdev_handle_port_attr_set(struct net_device *dev,
 			struct switchdev_notifier_port_attr_info *port_attr_info,
 			bool (*check_cb)(const struct net_device *dev),
-			int (*set_cb)(struct net_device *dev,
+			int (*set_cb)(struct net_device *dev, const void *ctx,
 				      const struct switchdev_attr *attr,
 				      struct netlink_ext_ack *extack))
 {