Merge branch 'dsa-changes-for-multiple-cpu-ports-part-4'

Vladimir Oltean says:

====================
DSA changes for multiple CPU ports (part 4)

Those who have been following part 1:
https://patchwork.kernel.org/project/netdevbpf/cover/20220511095020.562461-1-vladimir.oltean@nxp.com/
part 2:
https://patchwork.kernel.org/project/netdevbpf/cover/20220521213743.2735445-1-vladimir.oltean@nxp.com/
and part 3:
https://patchwork.kernel.org/project/netdevbpf/cover/20220819174820.3585002-1-vladimir.oltean@nxp.com/
will know that I am trying to enable the second internal port pair from
the NXP LS1028A Felix switch for DSA-tagged traffic via "ocelot-8021q".

This series represents the final part of that effort. We have:

- the introduction of new UAPI in the form of IFLA_DSA_MASTER, the
  iproute2 patch for which is here:
  https://patchwork.kernel.org/project/netdevbpf/patch/20220904190025.813574-1-vladimir.oltean@nxp.com/

- preparation for LAG DSA masters in terms of suppressing some
  operations for masters in the DSA core that simply don't make sense
  when those masters are a bonding/team interface

- handling all the net device events that occur between DSA and a
  LAG DSA master, including migration to a different DSA master when the
  current master joins a LAG, or the LAG gets destroyed

- updating documentation

- adding an implementation for NXP LS1028A, where things are insanely
  complicated due to hardware limitations. We have 2 tagging protocols:

  * the native "ocelot" protocol (NPI port mode). This does not support
    CPU ports in a LAG, and supports a single DSA master. The DSA master
    can be changed between eno2 (2.5G) and eno3 (1G), but all ports must
    be down during the changing process, and user ports assigned to the
    old DSA master will refuse to come up if the user requests that
    during a "transient" state.

  * the "ocelot-8021q" software-defined protocol, where the Ethernet
    ports connected to the CPU are not actually "god mode" ports as far
    as the hardware is concerned. So here, static assignment between
    user and CPU ports is possible by editing the PGID_SRC masks for
    the port-based forwarding matrix, and "CPU ports in a LAG" simply
    means "a LAG like any other".

The series was regression-tested on LS1028A using the local_termination.sh
kselftest, in most of the possible operating modes and tagging protocols.
I have not done a detailed performance evaluation yet, but using LAG, is
possible to exceed the termination bandwidth of a single CPU port in an
iperf3 test with multiple senders and multiple receivers.

v1 at:
https://patchwork.kernel.org/project/netdevbpf/cover/20220830195932.683432-1-vladimir.oltean@nxp.com/

Previous (older) RFC at:
https://lore.kernel.org/netdev/20220523104256.3556016-1-olteanv@gmail.com/
====================

Link: https://lore.kernel.org/r/20220911010706.2137967-1-vladimir.oltean@nxp.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

1 files changed, 146 insertions, 14 deletions

diff --git a/net/dsa/port.c b/net/dsa/port.c
index 7afc35db0c29c..e6289a1db0a08 100644
--- a/net/dsa/port.c
+++ b/net/dsa/port.c
@@ -7,6 +7,7 @@
  */
 
 #include <linux/if_bridge.h>
+#include <linux/netdevice.h>
 #include <linux/notifier.h>
 #include <linux/of_mdio.h>
 #include <linux/of_net.h>
@@ -634,6 +635,7 @@ int dsa_port_lag_join(struct dsa_port *dp, struct net_device *lag_dev,
 	struct dsa_notifier_lag_info info = {
 		.dp = dp,
 		.info = uinfo,
+		.extack = extack,
 	};
 	struct net_device *bridge_dev;
 	int err;
@@ -1026,7 +1028,7 @@ int dsa_port_standalone_host_fdb_add(struct dsa_port *dp,
 int dsa_port_bridge_host_fdb_add(struct dsa_port *dp,
 				 const unsigned char *addr, u16 vid)
 {
-	struct dsa_port *cpu_dp = dp->cpu_dp;
+	struct net_device *master = dsa_port_to_master(dp);
 	struct dsa_db db = {
 		.type = DSA_DB_BRIDGE,
 		.bridge = *dp->bridge,
@@ -1037,8 +1039,8 @@ int dsa_port_bridge_host_fdb_add(struct dsa_port *dp,
 	 * requires rtnl_lock(), since we can't guarantee that is held here,
 	 * and we can't take it either.
 	 */
-	if (cpu_dp->master->priv_flags & IFF_UNICAST_FLT) {
-		err = dev_uc_add(cpu_dp->master, addr);
+	if (master->priv_flags & IFF_UNICAST_FLT) {
+		err = dev_uc_add(master, addr);
 		if (err)
 			return err;
 	}
@@ -1077,15 +1079,15 @@ int dsa_port_standalone_host_fdb_del(struct dsa_port *dp,
 int dsa_port_bridge_host_fdb_del(struct dsa_port *dp,
 				 const unsigned char *addr, u16 vid)
 {
-	struct dsa_port *cpu_dp = dp->cpu_dp;
+	struct net_device *master = dsa_port_to_master(dp);
 	struct dsa_db db = {
 		.type = DSA_DB_BRIDGE,
 		.bridge = *dp->bridge,
 	};
 	int err;
 
-	if (cpu_dp->master->priv_flags & IFF_UNICAST_FLT) {
-		err = dev_uc_del(cpu_dp->master, addr);
+	if (master->priv_flags & IFF_UNICAST_FLT) {
+		err = dev_uc_del(master, addr);
 		if (err)
 			return err;
 	}
@@ -1208,14 +1210,14 @@ int dsa_port_standalone_host_mdb_add(const struct dsa_port *dp,
 int dsa_port_bridge_host_mdb_add(const struct dsa_port *dp,
 				 const struct switchdev_obj_port_mdb *mdb)
 {
-	struct dsa_port *cpu_dp = dp->cpu_dp;
+	struct net_device *master = dsa_port_to_master(dp);
 	struct dsa_db db = {
 		.type = DSA_DB_BRIDGE,
 		.bridge = *dp->bridge,
 	};
 	int err;
 
-	err = dev_mc_add(cpu_dp->master, mdb->addr);
+	err = dev_mc_add(master, mdb->addr);
 	if (err)
 		return err;
 
@@ -1252,14 +1254,14 @@ int dsa_port_standalone_host_mdb_del(const struct dsa_port *dp,
 int dsa_port_bridge_host_mdb_del(const struct dsa_port *dp,
 				 const struct switchdev_obj_port_mdb *mdb)
 {
-	struct dsa_port *cpu_dp = dp->cpu_dp;
+	struct net_device *master = dsa_port_to_master(dp);
 	struct dsa_db db = {
 		.type = DSA_DB_BRIDGE,
 		.bridge = *dp->bridge,
 	};
 	int err;
 
-	err = dev_mc_del(cpu_dp->master, mdb->addr);
+	err = dev_mc_del(master, mdb->addr);
 	if (err)
 		return err;
 
@@ -1294,19 +1296,19 @@ int dsa_port_host_vlan_add(struct dsa_port *dp,
 			   const struct switchdev_obj_port_vlan *vlan,
 			   struct netlink_ext_ack *extack)
 {
+	struct net_device *master = dsa_port_to_master(dp);
 	struct dsa_notifier_vlan_info info = {
 		.dp = dp,
 		.vlan = vlan,
 		.extack = extack,
 	};
-	struct dsa_port *cpu_dp = dp->cpu_dp;
 	int err;
 
 	err = dsa_port_notify(dp, DSA_NOTIFIER_HOST_VLAN_ADD, &info);
 	if (err && err != -EOPNOTSUPP)
 		return err;
 
-	vlan_vid_add(cpu_dp->master, htons(ETH_P_8021Q), vlan->vid);
+	vlan_vid_add(master, htons(ETH_P_8021Q), vlan->vid);
 
 	return err;
 }
@@ -1314,18 +1316,18 @@ int dsa_port_host_vlan_add(struct dsa_port *dp,
 int dsa_port_host_vlan_del(struct dsa_port *dp,
 			   const struct switchdev_obj_port_vlan *vlan)
 {
+	struct net_device *master = dsa_port_to_master(dp);
 	struct dsa_notifier_vlan_info info = {
 		.dp = dp,
 		.vlan = vlan,
 	};
-	struct dsa_port *cpu_dp = dp->cpu_dp;
 	int err;
 
 	err = dsa_port_notify(dp, DSA_NOTIFIER_HOST_VLAN_DEL, &info);
 	if (err && err != -EOPNOTSUPP)
 		return err;
 
-	vlan_vid_del(cpu_dp->master, htons(ETH_P_8021Q), vlan->vid);
+	vlan_vid_del(master, htons(ETH_P_8021Q), vlan->vid);
 
 	return err;
 }
@@ -1374,6 +1376,136 @@ int dsa_port_mrp_del_ring_role(const struct dsa_port *dp,
 	return ds->ops->port_mrp_del_ring_role(ds, dp->index, mrp);
 }
 
+static int dsa_port_assign_master(struct dsa_port *dp,
+				  struct net_device *master,
+				  struct netlink_ext_ack *extack,
+				  bool fail_on_err)
+{
+	struct dsa_switch *ds = dp->ds;
+	int port = dp->index, err;
+
+	err = ds->ops->port_change_master(ds, port, master, extack);
+	if (err && !fail_on_err)
+		dev_err(ds->dev, "port %d failed to assign master %s: %pe\n",
+			port, master->name, ERR_PTR(err));
+
+	if (err && fail_on_err)
+		return err;
+
+	dp->cpu_dp = master->dsa_ptr;
+	dp->cpu_port_in_lag = netif_is_lag_master(master);
+
+	return 0;
+}
+
+/* Change the dp->cpu_dp affinity for a user port. Note that both cross-chip
+ * notifiers and drivers have implicit assumptions about user-to-CPU-port
+ * mappings, so we unfortunately cannot delay the deletion of the objects
+ * (switchdev, standalone addresses, standalone VLANs) on the old CPU port
+ * until the new CPU port has been set up. So we need to completely tear down
+ * the old CPU port before changing it, and restore it on errors during the
+ * bringup of the new one.
+ */
+int dsa_port_change_master(struct dsa_port *dp, struct net_device *master,
+			   struct netlink_ext_ack *extack)
+{
+	struct net_device *bridge_dev = dsa_port_bridge_dev_get(dp);
+	struct net_device *old_master = dsa_port_to_master(dp);
+	struct net_device *dev = dp->slave;
+	struct dsa_switch *ds = dp->ds;
+	bool vlan_filtering;
+	int err, tmp;
+
+	/* Bridges may hold host FDB, MDB and VLAN objects. These need to be
+	 * migrated, so dynamically unoffload and later reoffload the bridge
+	 * port.
+	 */
+	if (bridge_dev) {
+		dsa_port_pre_bridge_leave(dp, bridge_dev);
+		dsa_port_bridge_leave(dp, bridge_dev);
+	}
+
+	/* The port might still be VLAN filtering even if it's no longer
+	 * under a bridge, either due to ds->vlan_filtering_is_global or
+	 * ds->needs_standalone_vlan_filtering. In turn this means VLANs
+	 * on the CPU port.
+	 */
+	vlan_filtering = dsa_port_is_vlan_filtering(dp);
+	if (vlan_filtering) {
+		err = dsa_slave_manage_vlan_filtering(dev, false);
+		if (err) {
+			NL_SET_ERR_MSG_MOD(extack,
+					   "Failed to remove standalone VLANs");
+			goto rewind_old_bridge;
+		}
+	}
+
+	/* Standalone addresses, and addresses of upper interfaces like
+	 * VLAN, LAG, HSR need to be migrated.
+	 */
+	dsa_slave_unsync_ha(dev);
+
+	err = dsa_port_assign_master(dp, master, extack, true);
+	if (err)
+		goto rewind_old_addrs;
+
+	dsa_slave_sync_ha(dev);
+
+	if (vlan_filtering) {
+		err = dsa_slave_manage_vlan_filtering(dev, true);
+		if (err) {
+			NL_SET_ERR_MSG_MOD(extack,
+					   "Failed to restore standalone VLANs");
+			goto rewind_new_addrs;
+		}
+	}
+
+	if (bridge_dev) {
+		err = dsa_port_bridge_join(dp, bridge_dev, extack);
+		if (err && err == -EOPNOTSUPP) {
+			NL_SET_ERR_MSG_MOD(extack,
+					   "Failed to reoffload bridge");
+			goto rewind_new_vlan;
+		}
+	}
+
+	return 0;
+
+rewind_new_vlan:
+	if (vlan_filtering)
+		dsa_slave_manage_vlan_filtering(dev, false);
+
+rewind_new_addrs:
+	dsa_slave_unsync_ha(dev);
+
+	dsa_port_assign_master(dp, old_master, NULL, false);
+
+/* Restore the objects on the old CPU port */
+rewind_old_addrs:
+	dsa_slave_sync_ha(dev);
+
+	if (vlan_filtering) {
+		tmp = dsa_slave_manage_vlan_filtering(dev, true);
+		if (tmp) {
+			dev_err(ds->dev,
+				"port %d failed to restore standalone VLANs: %pe\n",
+				dp->index, ERR_PTR(tmp));
+		}
+	}
+
+rewind_old_bridge:
+	if (bridge_dev) {
+		tmp = dsa_port_bridge_join(dp, bridge_dev, extack);
+		if (tmp) {
+			dev_err(ds->dev,
+				"port %d failed to rejoin bridge %s: %pe\n",
+				dp->index, bridge_dev->name, ERR_PTR(tmp));
+		}
+	}
+
+	return err;
+}
+
 void dsa_port_set_tag_protocol(struct dsa_port *cpu_dp,
 			       const struct dsa_device_ops *tag_ops)
 {