root/net/dsa/user.c
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * net/dsa/user.c - user device handling
 * Copyright (c) 2008-2009 Marvell Semiconductor
 */

#include <linux/list.h>
#include <linux/etherdevice.h>
#include <linux/netdevice.h>
#include <linux/phy.h>
#include <linux/phy_fixed.h>
#include <linux/phylink.h>
#include <linux/of_net.h>
#include <linux/of_mdio.h>
#include <linux/mdio.h>
#include <net/rtnetlink.h>
#include <net/pkt_cls.h>
#include <net/selftests.h>
#include <net/tc_act/tc_mirred.h>
#include <linux/if_bridge.h>
#include <linux/if_hsr.h>
#include <net/dcbnl.h>
#include <linux/netpoll.h>
#include <linux/string.h>

#include "conduit.h"
#include "dsa.h"
#include "netlink.h"
#include "port.h"
#include "switch.h"
#include "tag.h"
#include "user.h"

struct dsa_switchdev_event_work {
        struct net_device *dev;
        struct net_device *orig_dev;
        struct work_struct work;
        unsigned long event;
        /* Specific for SWITCHDEV_FDB_ADD_TO_DEVICE and
         * SWITCHDEV_FDB_DEL_TO_DEVICE
         */
        unsigned char addr[ETH_ALEN];
        u16 vid;
        bool host_addr;
};

enum dsa_standalone_event {
        DSA_UC_ADD,
        DSA_UC_DEL,
        DSA_MC_ADD,
        DSA_MC_DEL,
};

struct dsa_standalone_event_work {
        struct work_struct work;
        struct net_device *dev;
        enum dsa_standalone_event event;
        unsigned char addr[ETH_ALEN];
        u16 vid;
};

struct dsa_host_vlan_rx_filtering_ctx {
        struct net_device *dev;
        const unsigned char *addr;
        enum dsa_standalone_event event;
};

static bool dsa_switch_supports_uc_filtering(struct dsa_switch *ds)
{
        return ds->ops->port_fdb_add && ds->ops->port_fdb_del &&
               ds->fdb_isolation && !ds->vlan_filtering_is_global &&
               !ds->needs_standalone_vlan_filtering;
}

static bool dsa_switch_supports_mc_filtering(struct dsa_switch *ds)
{
        return ds->ops->port_mdb_add && ds->ops->port_mdb_del &&
               ds->fdb_isolation && !ds->vlan_filtering_is_global &&
               !ds->needs_standalone_vlan_filtering;
}

static void dsa_user_standalone_event_work(struct work_struct *work)
{
        struct dsa_standalone_event_work *standalone_work =
                container_of(work, struct dsa_standalone_event_work, work);
        const unsigned char *addr = standalone_work->addr;
        struct net_device *dev = standalone_work->dev;
        struct dsa_port *dp = dsa_user_to_port(dev);
        struct switchdev_obj_port_mdb mdb;
        struct dsa_switch *ds = dp->ds;
        u16 vid = standalone_work->vid;
        int err;

        switch (standalone_work->event) {
        case DSA_UC_ADD:
                err = dsa_port_standalone_host_fdb_add(dp, addr, vid);
                if (err) {
                        dev_err(ds->dev,
                                "port %d failed to add %pM vid %d to fdb: %d\n",
                                dp->index, addr, vid, err);
                        break;
                }
                break;

        case DSA_UC_DEL:
                err = dsa_port_standalone_host_fdb_del(dp, addr, vid);
                if (err) {
                        dev_err(ds->dev,
                                "port %d failed to delete %pM vid %d from fdb: %d\n",
                                dp->index, addr, vid, err);
                }

                break;
        case DSA_MC_ADD:
                ether_addr_copy(mdb.addr, addr);
                mdb.vid = vid;

                err = dsa_port_standalone_host_mdb_add(dp, &mdb);
                if (err) {
                        dev_err(ds->dev,
                                "port %d failed to add %pM vid %d to mdb: %d\n",
                                dp->index, addr, vid, err);
                        break;
                }
                break;
        case DSA_MC_DEL:
                ether_addr_copy(mdb.addr, addr);
                mdb.vid = vid;

                err = dsa_port_standalone_host_mdb_del(dp, &mdb);
                if (err) {
                        dev_err(ds->dev,
                                "port %d failed to delete %pM vid %d from mdb: %d\n",
                                dp->index, addr, vid, err);
                }

                break;
        }

        kfree(standalone_work);
}

static int dsa_user_schedule_standalone_work(struct net_device *dev,
                                             enum dsa_standalone_event event,
                                             const unsigned char *addr,
                                             u16 vid)
{
        struct dsa_standalone_event_work *standalone_work;

        standalone_work = kzalloc_obj(*standalone_work, GFP_ATOMIC);
        if (!standalone_work)
                return -ENOMEM;

        INIT_WORK(&standalone_work->work, dsa_user_standalone_event_work);
        standalone_work->event = event;
        standalone_work->dev = dev;

        ether_addr_copy(standalone_work->addr, addr);
        standalone_work->vid = vid;

        dsa_schedule_work(&standalone_work->work);

        return 0;
}

static int dsa_user_host_vlan_rx_filtering(void *arg, int vid)
{
        struct dsa_host_vlan_rx_filtering_ctx *ctx = arg;

        return dsa_user_schedule_standalone_work(ctx->dev, ctx->event,
                                                  ctx->addr, vid);
}

static int dsa_user_vlan_for_each(struct net_device *dev,
                                  int (*cb)(void *arg, int vid), void *arg)
{
        struct dsa_port *dp = dsa_user_to_port(dev);
        struct dsa_vlan *v;
        int err;

        lockdep_assert_held(&dev->addr_list_lock);

        err = cb(arg, 0);
        if (err)
                return err;

        list_for_each_entry(v, &dp->user_vlans, list) {
                err = cb(arg, v->vid);
                if (err)
                        return err;
        }

        return 0;
}

static int dsa_user_sync_uc(struct net_device *dev,
                            const unsigned char *addr)
{
        struct net_device *conduit = dsa_user_to_conduit(dev);
        struct dsa_port *dp = dsa_user_to_port(dev);
        struct dsa_host_vlan_rx_filtering_ctx ctx = {
                .dev = dev,
                .addr = addr,
                .event = DSA_UC_ADD,
        };

        dev_uc_add(conduit, addr);

        if (!dsa_switch_supports_uc_filtering(dp->ds))
                return 0;

        return dsa_user_vlan_for_each(dev, dsa_user_host_vlan_rx_filtering,
                                      &ctx);
}

static int dsa_user_unsync_uc(struct net_device *dev,
                              const unsigned char *addr)
{
        struct net_device *conduit = dsa_user_to_conduit(dev);
        struct dsa_port *dp = dsa_user_to_port(dev);
        struct dsa_host_vlan_rx_filtering_ctx ctx = {
                .dev = dev,
                .addr = addr,
                .event = DSA_UC_DEL,
        };

        dev_uc_del(conduit, addr);

        if (!dsa_switch_supports_uc_filtering(dp->ds))
                return 0;

        return dsa_user_vlan_for_each(dev, dsa_user_host_vlan_rx_filtering,
                                      &ctx);
}

static int dsa_user_sync_mc(struct net_device *dev,
                            const unsigned char *addr)
{
        struct net_device *conduit = dsa_user_to_conduit(dev);
        struct dsa_port *dp = dsa_user_to_port(dev);
        struct dsa_host_vlan_rx_filtering_ctx ctx = {
                .dev = dev,
                .addr = addr,
                .event = DSA_MC_ADD,
        };

        dev_mc_add(conduit, addr);

        if (!dsa_switch_supports_mc_filtering(dp->ds))
                return 0;

        return dsa_user_vlan_for_each(dev, dsa_user_host_vlan_rx_filtering,
                                      &ctx);
}

static int dsa_user_unsync_mc(struct net_device *dev,
                              const unsigned char *addr)
{
        struct net_device *conduit = dsa_user_to_conduit(dev);
        struct dsa_port *dp = dsa_user_to_port(dev);
        struct dsa_host_vlan_rx_filtering_ctx ctx = {
                .dev = dev,
                .addr = addr,
                .event = DSA_MC_DEL,
        };

        dev_mc_del(conduit, addr);

        if (!dsa_switch_supports_mc_filtering(dp->ds))
                return 0;

        return dsa_user_vlan_for_each(dev, dsa_user_host_vlan_rx_filtering,
                                      &ctx);
}

void dsa_user_sync_ha(struct net_device *dev)
{
        struct dsa_port *dp = dsa_user_to_port(dev);
        struct dsa_switch *ds = dp->ds;
        struct netdev_hw_addr *ha;

        netif_addr_lock_bh(dev);

        netdev_for_each_synced_mc_addr(ha, dev)
                dsa_user_sync_mc(dev, ha->addr);

        netdev_for_each_synced_uc_addr(ha, dev)
                dsa_user_sync_uc(dev, ha->addr);

        netif_addr_unlock_bh(dev);

        if (dsa_switch_supports_uc_filtering(ds) ||
            dsa_switch_supports_mc_filtering(ds))
                dsa_flush_workqueue();
}

void dsa_user_unsync_ha(struct net_device *dev)
{
        struct dsa_port *dp = dsa_user_to_port(dev);
        struct dsa_switch *ds = dp->ds;
        struct netdev_hw_addr *ha;

        netif_addr_lock_bh(dev);

        netdev_for_each_synced_uc_addr(ha, dev)
                dsa_user_unsync_uc(dev, ha->addr);

        netdev_for_each_synced_mc_addr(ha, dev)
                dsa_user_unsync_mc(dev, ha->addr);

        netif_addr_unlock_bh(dev);

        if (dsa_switch_supports_uc_filtering(ds) ||
            dsa_switch_supports_mc_filtering(ds))
                dsa_flush_workqueue();
}

/* user mii_bus handling ***************************************************/
static int dsa_user_phy_read(struct mii_bus *bus, int addr, int reg)
{
        struct dsa_switch *ds = bus->priv;

        if (ds->phys_mii_mask & (1 << addr))
                return ds->ops->phy_read(ds, addr, reg);

        return 0xffff;
}

static int dsa_user_phy_write(struct mii_bus *bus, int addr, int reg, u16 val)
{
        struct dsa_switch *ds = bus->priv;

        if (ds->phys_mii_mask & (1 << addr))
                return ds->ops->phy_write(ds, addr, reg, val);

        return 0;
}

void dsa_user_mii_bus_init(struct dsa_switch *ds)
{
        ds->user_mii_bus->priv = (void *)ds;
        ds->user_mii_bus->name = "dsa user smi";
        ds->user_mii_bus->read = dsa_user_phy_read;
        ds->user_mii_bus->write = dsa_user_phy_write;
        snprintf(ds->user_mii_bus->id, MII_BUS_ID_SIZE, "dsa-%d.%d",
                 ds->dst->index, ds->index);
        ds->user_mii_bus->parent = ds->dev;
        ds->user_mii_bus->phy_mask = ~ds->phys_mii_mask;
}


/* user device handling ****************************************************/
static int dsa_user_get_iflink(const struct net_device *dev)
{
        return READ_ONCE(dsa_user_to_conduit(dev)->ifindex);
}

int dsa_user_host_uc_install(struct net_device *dev, const u8 *addr)
{
        struct net_device *conduit = dsa_user_to_conduit(dev);
        struct dsa_port *dp = dsa_user_to_port(dev);
        struct dsa_switch *ds = dp->ds;
        int err;

        if (dsa_switch_supports_uc_filtering(ds)) {
                err = dsa_port_standalone_host_fdb_add(dp, addr, 0);
                if (err)
                        goto out;
        }

        if (!ether_addr_equal(addr, conduit->dev_addr)) {
                err = dev_uc_add(conduit, addr);
                if (err < 0)
                        goto del_host_addr;
        }

        return 0;

del_host_addr:
        if (dsa_switch_supports_uc_filtering(ds))
                dsa_port_standalone_host_fdb_del(dp, addr, 0);
out:
        return err;
}

void dsa_user_host_uc_uninstall(struct net_device *dev)
{
        struct net_device *conduit = dsa_user_to_conduit(dev);
        struct dsa_port *dp = dsa_user_to_port(dev);
        struct dsa_switch *ds = dp->ds;

        if (!ether_addr_equal(dev->dev_addr, conduit->dev_addr))
                dev_uc_del(conduit, dev->dev_addr);

        if (dsa_switch_supports_uc_filtering(ds))
                dsa_port_standalone_host_fdb_del(dp, dev->dev_addr, 0);
}

static int dsa_user_open(struct net_device *dev)
{
        struct net_device *conduit = dsa_user_to_conduit(dev);
        struct dsa_port *dp = dsa_user_to_port(dev);
        int err;

        err = dev_open(conduit, NULL);
        if (err < 0) {
                netdev_err(dev, "failed to open conduit %s\n", conduit->name);
                goto out;
        }

        err = dsa_user_host_uc_install(dev, dev->dev_addr);
        if (err)
                goto out;

        err = dsa_port_enable_rt(dp, dev->phydev);
        if (err)
                goto out_del_host_uc;

        return 0;

out_del_host_uc:
        dsa_user_host_uc_uninstall(dev);
out:
        return err;
}

static int dsa_user_close(struct net_device *dev)
{
        struct dsa_port *dp = dsa_user_to_port(dev);

        dsa_port_disable_rt(dp);

        dsa_user_host_uc_uninstall(dev);

        return 0;
}

static void dsa_user_manage_host_flood(struct net_device *dev)
{
        bool mc = dev->flags & (IFF_PROMISC | IFF_ALLMULTI);
        struct dsa_port *dp = dsa_user_to_port(dev);
        bool uc = dev->flags & IFF_PROMISC;

        dsa_port_set_host_flood(dp, uc, mc);
}

static void dsa_user_change_rx_flags(struct net_device *dev, int change)
{
        struct net_device *conduit = dsa_user_to_conduit(dev);
        struct dsa_port *dp = dsa_user_to_port(dev);
        struct dsa_switch *ds = dp->ds;

        if (change & IFF_ALLMULTI)
                dev_set_allmulti(conduit,
                                 dev->flags & IFF_ALLMULTI ? 1 : -1);
        if (change & IFF_PROMISC)
                dev_set_promiscuity(conduit,
                                    dev->flags & IFF_PROMISC ? 1 : -1);

        if (dsa_switch_supports_uc_filtering(ds) &&
            dsa_switch_supports_mc_filtering(ds))
                dsa_user_manage_host_flood(dev);
}

static void dsa_user_set_rx_mode(struct net_device *dev)
{
        __dev_mc_sync(dev, dsa_user_sync_mc, dsa_user_unsync_mc);
        __dev_uc_sync(dev, dsa_user_sync_uc, dsa_user_unsync_uc);
}

static int dsa_user_set_mac_address(struct net_device *dev, void *a)
{
        struct dsa_port *dp = dsa_user_to_port(dev);
        struct dsa_switch *ds = dp->ds;
        struct sockaddr *addr = a;
        int err;

        if (!is_valid_ether_addr(addr->sa_data))
                return -EADDRNOTAVAIL;

        if (ds->ops->port_set_mac_address) {
                err = ds->ops->port_set_mac_address(ds, dp->index,
                                                    addr->sa_data);
                if (err)
                        return err;
        }

        /* If the port is down, the address isn't synced yet to hardware or
         * to the DSA conduit, so there is nothing to change.
         */
        if (!(dev->flags & IFF_UP))
                goto out_change_dev_addr;

        err = dsa_user_host_uc_install(dev, addr->sa_data);
        if (err)
                return err;

        dsa_user_host_uc_uninstall(dev);

out_change_dev_addr:
        eth_hw_addr_set(dev, addr->sa_data);

        return 0;
}

struct dsa_user_dump_ctx {
        struct net_device *dev;
        struct sk_buff *skb;
        struct netlink_callback *cb;
        int idx;
};

static int
dsa_user_port_fdb_do_dump(const unsigned char *addr, u16 vid,
                          bool is_static, void *data)
{
        struct dsa_user_dump_ctx *dump = data;
        struct ndo_fdb_dump_context *ctx = (void *)dump->cb->ctx;
        u32 portid = NETLINK_CB(dump->cb->skb).portid;
        u32 seq = dump->cb->nlh->nlmsg_seq;
        struct nlmsghdr *nlh;
        struct ndmsg *ndm;

        if (dump->idx < ctx->fdb_idx)
                goto skip;

        nlh = nlmsg_put(dump->skb, portid, seq, RTM_NEWNEIGH,
                        sizeof(*ndm), NLM_F_MULTI);
        if (!nlh)
                return -EMSGSIZE;

        ndm = nlmsg_data(nlh);
        ndm->ndm_family  = AF_BRIDGE;
        ndm->ndm_pad1    = 0;
        ndm->ndm_pad2    = 0;
        ndm->ndm_flags   = NTF_SELF;
        ndm->ndm_type    = 0;
        ndm->ndm_ifindex = dump->dev->ifindex;
        ndm->ndm_state   = is_static ? NUD_NOARP : NUD_REACHABLE;

        if (nla_put(dump->skb, NDA_LLADDR, ETH_ALEN, addr))
                goto nla_put_failure;

        if (vid && nla_put_u16(dump->skb, NDA_VLAN, vid))
                goto nla_put_failure;

        nlmsg_end(dump->skb, nlh);

skip:
        dump->idx++;
        return 0;

nla_put_failure:
        nlmsg_cancel(dump->skb, nlh);
        return -EMSGSIZE;
}

static int
dsa_user_fdb_dump(struct sk_buff *skb, struct netlink_callback *cb,
                  struct net_device *dev, struct net_device *filter_dev,
                  int *idx)
{
        struct dsa_port *dp = dsa_user_to_port(dev);
        struct dsa_user_dump_ctx dump = {
                .dev = dev,
                .skb = skb,
                .cb = cb,
                .idx = *idx,
        };
        int err;

        err = dsa_port_fdb_dump(dp, dsa_user_port_fdb_do_dump, &dump);
        *idx = dump.idx;

        return err;
}

static int dsa_user_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
{
        struct dsa_user_priv *p = netdev_priv(dev);

        return phylink_mii_ioctl(p->dp->pl, ifr, cmd);
}

static int dsa_user_port_attr_set(struct net_device *dev, const void *ctx,
                                  const struct switchdev_attr *attr,
                                  struct netlink_ext_ack *extack)
{
        struct dsa_port *dp = dsa_user_to_port(dev);
        int ret;

        if (ctx && ctx != dp)
                return 0;

        switch (attr->id) {
        case SWITCHDEV_ATTR_ID_PORT_STP_STATE:
                if (!dsa_port_offloads_bridge_port(dp, attr->orig_dev))
                        return -EOPNOTSUPP;

                ret = dsa_port_set_state(dp, attr->u.stp_state, true);
                break;
        case SWITCHDEV_ATTR_ID_PORT_MST_STATE:
                if (!dsa_port_offloads_bridge_port(dp, attr->orig_dev))
                        return -EOPNOTSUPP;

                ret = dsa_port_set_mst_state(dp, &attr->u.mst_state, extack);
                break;
        case SWITCHDEV_ATTR_ID_BRIDGE_VLAN_FILTERING:
                if (!dsa_port_offloads_bridge_dev(dp, attr->orig_dev))
                        return -EOPNOTSUPP;

                ret = dsa_port_vlan_filtering(dp, attr->u.vlan_filtering,
                                              extack);
                break;
        case SWITCHDEV_ATTR_ID_BRIDGE_AGEING_TIME:
                if (!dsa_port_offloads_bridge_dev(dp, attr->orig_dev))
                        return -EOPNOTSUPP;

                ret = dsa_port_ageing_time(dp, attr->u.ageing_time);
                break;
        case SWITCHDEV_ATTR_ID_BRIDGE_MST:
                if (!dsa_port_offloads_bridge_dev(dp, attr->orig_dev))
                        return -EOPNOTSUPP;

                ret = dsa_port_mst_enable(dp, attr->u.mst, extack);
                break;
        case SWITCHDEV_ATTR_ID_PORT_PRE_BRIDGE_FLAGS:
                if (!dsa_port_offloads_bridge_port(dp, attr->orig_dev))
                        return -EOPNOTSUPP;

                ret = dsa_port_pre_bridge_flags(dp, attr->u.brport_flags,
                                                extack);
                break;
        case SWITCHDEV_ATTR_ID_PORT_BRIDGE_FLAGS:
                if (!dsa_port_offloads_bridge_port(dp, attr->orig_dev))
                        return -EOPNOTSUPP;

                ret = dsa_port_bridge_flags(dp, attr->u.brport_flags, extack);
                break;
        case SWITCHDEV_ATTR_ID_VLAN_MSTI:
                if (!dsa_port_offloads_bridge_dev(dp, attr->orig_dev))
                        return -EOPNOTSUPP;

                ret = dsa_port_vlan_msti(dp, &attr->u.vlan_msti);
                break;
        default:
                ret = -EOPNOTSUPP;
                break;
        }

        return ret;
}

/* Must be called under rcu_read_lock() */
static int
dsa_user_vlan_check_for_8021q_uppers(struct net_device *user,
                                     const struct switchdev_obj_port_vlan *vlan)
{
        struct net_device *upper_dev;
        struct list_head *iter;

        netdev_for_each_upper_dev_rcu(user, upper_dev, iter) {
                u16 vid;

                if (!is_vlan_dev(upper_dev))
                        continue;

                vid = vlan_dev_vlan_id(upper_dev);
                if (vid == vlan->vid)
                        return -EBUSY;
        }

        return 0;
}

static int dsa_user_vlan_add(struct net_device *dev,
                             const struct switchdev_obj *obj,
                             struct netlink_ext_ack *extack)
{
        struct dsa_port *dp = dsa_user_to_port(dev);
        struct switchdev_obj_port_vlan *vlan;
        int err;

        if (dsa_port_skip_vlan_configuration(dp)) {
                NL_SET_ERR_MSG_MOD(extack, "skipping configuration of VLAN");
                return 0;
        }

        vlan = SWITCHDEV_OBJ_PORT_VLAN(obj);

        /* Deny adding a bridge VLAN when there is already an 802.1Q upper with
         * the same VID.
         */
        if (br_vlan_enabled(dsa_port_bridge_dev_get(dp))) {
                rcu_read_lock();
                err = dsa_user_vlan_check_for_8021q_uppers(dev, vlan);
                rcu_read_unlock();
                if (err) {
                        NL_SET_ERR_MSG_MOD(extack,
                                           "Port already has a VLAN upper with this VID");
                        return err;
                }
        }

        return dsa_port_vlan_add(dp, vlan, extack);
}

/* Offload a VLAN installed on the bridge or on a foreign interface by
 * installing it as a VLAN towards the CPU port.
 */
static int dsa_user_host_vlan_add(struct net_device *dev,
                                  const struct switchdev_obj *obj,
                                  struct netlink_ext_ack *extack)
{
        struct dsa_port *dp = dsa_user_to_port(dev);
        struct switchdev_obj_port_vlan vlan;

        /* Do nothing if this is a software bridge */
        if (!dp->bridge)
                return -EOPNOTSUPP;

        if (dsa_port_skip_vlan_configuration(dp)) {
                NL_SET_ERR_MSG_MOD(extack, "skipping configuration of VLAN");
                return 0;
        }

        vlan = *SWITCHDEV_OBJ_PORT_VLAN(obj);

        /* Even though drivers often handle CPU membership in special ways,
         * it doesn't make sense to program a PVID, so clear this flag.
         */
        vlan.flags &= ~BRIDGE_VLAN_INFO_PVID;

        return dsa_port_host_vlan_add(dp, &vlan, extack);
}

static int dsa_user_port_obj_add(struct net_device *dev, const void *ctx,
                                 const struct switchdev_obj *obj,
                                 struct netlink_ext_ack *extack)
{
        struct dsa_port *dp = dsa_user_to_port(dev);
        int err;

        if (ctx && ctx != dp)
                return 0;

        switch (obj->id) {
        case SWITCHDEV_OBJ_ID_PORT_MDB:
                if (!dsa_port_offloads_bridge_port(dp, obj->orig_dev))
                        return -EOPNOTSUPP;

                err = dsa_port_mdb_add(dp, SWITCHDEV_OBJ_PORT_MDB(obj));
                break;
        case SWITCHDEV_OBJ_ID_HOST_MDB:
                if (!dsa_port_offloads_bridge_dev(dp, obj->orig_dev))
                        return -EOPNOTSUPP;

                err = dsa_port_bridge_host_mdb_add(dp, SWITCHDEV_OBJ_PORT_MDB(obj));
                break;
        case SWITCHDEV_OBJ_ID_PORT_VLAN:
                if (dsa_port_offloads_bridge_port(dp, obj->orig_dev))
                        err = dsa_user_vlan_add(dev, obj, extack);
                else
                        err = dsa_user_host_vlan_add(dev, obj, extack);
                break;
        case SWITCHDEV_OBJ_ID_MRP:
                if (!dsa_port_offloads_bridge_dev(dp, obj->orig_dev))
                        return -EOPNOTSUPP;

                err = dsa_port_mrp_add(dp, SWITCHDEV_OBJ_MRP(obj));
                break;
        case SWITCHDEV_OBJ_ID_RING_ROLE_MRP:
                if (!dsa_port_offloads_bridge_dev(dp, obj->orig_dev))
                        return -EOPNOTSUPP;

                err = dsa_port_mrp_add_ring_role(dp,
                                                 SWITCHDEV_OBJ_RING_ROLE_MRP(obj));
                break;
        default:
                err = -EOPNOTSUPP;
                break;
        }

        return err;
}

static int dsa_user_vlan_del(struct net_device *dev,
                             const struct switchdev_obj *obj)
{
        struct dsa_port *dp = dsa_user_to_port(dev);
        struct switchdev_obj_port_vlan *vlan;

        if (dsa_port_skip_vlan_configuration(dp))
                return 0;

        vlan = SWITCHDEV_OBJ_PORT_VLAN(obj);

        return dsa_port_vlan_del(dp, vlan);
}

static int dsa_user_host_vlan_del(struct net_device *dev,
                                  const struct switchdev_obj *obj)
{
        struct dsa_port *dp = dsa_user_to_port(dev);
        struct switchdev_obj_port_vlan *vlan;

        /* Do nothing if this is a software bridge */
        if (!dp->bridge)
                return -EOPNOTSUPP;

        if (dsa_port_skip_vlan_configuration(dp))
                return 0;

        vlan = SWITCHDEV_OBJ_PORT_VLAN(obj);

        return dsa_port_host_vlan_del(dp, vlan);
}

static int dsa_user_port_obj_del(struct net_device *dev, const void *ctx,
                                 const struct switchdev_obj *obj)
{
        struct dsa_port *dp = dsa_user_to_port(dev);
        int err;

        if (ctx && ctx != dp)
                return 0;

        switch (obj->id) {
        case SWITCHDEV_OBJ_ID_PORT_MDB:
                if (!dsa_port_offloads_bridge_port(dp, obj->orig_dev))
                        return -EOPNOTSUPP;

                err = dsa_port_mdb_del(dp, SWITCHDEV_OBJ_PORT_MDB(obj));
                break;
        case SWITCHDEV_OBJ_ID_HOST_MDB:
                if (!dsa_port_offloads_bridge_dev(dp, obj->orig_dev))
                        return -EOPNOTSUPP;

                err = dsa_port_bridge_host_mdb_del(dp, SWITCHDEV_OBJ_PORT_MDB(obj));
                break;
        case SWITCHDEV_OBJ_ID_PORT_VLAN:
                if (dsa_port_offloads_bridge_port(dp, obj->orig_dev))
                        err = dsa_user_vlan_del(dev, obj);
                else
                        err = dsa_user_host_vlan_del(dev, obj);
                break;
        case SWITCHDEV_OBJ_ID_MRP:
                if (!dsa_port_offloads_bridge_dev(dp, obj->orig_dev))
                        return -EOPNOTSUPP;

                err = dsa_port_mrp_del(dp, SWITCHDEV_OBJ_MRP(obj));
                break;
        case SWITCHDEV_OBJ_ID_RING_ROLE_MRP:
                if (!dsa_port_offloads_bridge_dev(dp, obj->orig_dev))
                        return -EOPNOTSUPP;

                err = dsa_port_mrp_del_ring_role(dp,
                                                 SWITCHDEV_OBJ_RING_ROLE_MRP(obj));
                break;
        default:
                err = -EOPNOTSUPP;
                break;
        }

        return err;
}

static netdev_tx_t dsa_user_netpoll_send_skb(struct net_device *dev,
                                             struct sk_buff *skb)
{
#ifdef CONFIG_NET_POLL_CONTROLLER
        struct dsa_user_priv *p = netdev_priv(dev);

        return netpoll_send_skb(p->netpoll, skb);
#else
        BUG();
        return NETDEV_TX_OK;
#endif
}

static void dsa_skb_tx_timestamp(struct dsa_user_priv *p,
                                 struct sk_buff *skb)
{
        struct dsa_switch *ds = p->dp->ds;

        if (!(skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP_NOBPF))
                return;

        if (!ds->ops->port_txtstamp)
                return;

        ds->ops->port_txtstamp(ds, p->dp->index, skb);
}

netdev_tx_t dsa_enqueue_skb(struct sk_buff *skb, struct net_device *dev)
{
        /* SKB for netpoll still need to be mangled with the protocol-specific
         * tag to be successfully transmitted
         */
        if (unlikely(netpoll_tx_running(dev)))
                return dsa_user_netpoll_send_skb(dev, skb);

        /* Queue the SKB for transmission on the parent interface, but
         * do not modify its EtherType
         */
        skb->dev = dsa_user_to_conduit(dev);
        dev_queue_xmit(skb);

        return NETDEV_TX_OK;
}
EXPORT_SYMBOL_GPL(dsa_enqueue_skb);

static netdev_tx_t dsa_user_xmit(struct sk_buff *skb, struct net_device *dev)
{
        struct dsa_user_priv *p = netdev_priv(dev);
        struct sk_buff *nskb;

        dev_sw_netstats_tx_add(dev, 1, skb->len);

        memset(skb->cb, 0, sizeof(skb->cb));

        /* Handle tx timestamp if any */
        dsa_skb_tx_timestamp(p, skb);

        if (skb_ensure_writable_head_tail(skb, dev)) {
                dev_kfree_skb_any(skb);
                return NETDEV_TX_OK;
        }

        /* needed_tailroom should still be 'warm' in the cache line from
         * skb_ensure_writable_head_tail(), which has also ensured that
         * padding is safe.
         */
        if (dev->needed_tailroom)
                eth_skb_pad(skb);

        /* Transmit function may have to reallocate the original SKB,
         * in which case it must have freed it. Only free it here on error.
         */
        nskb = p->xmit(skb, dev);
        if (!nskb) {
                kfree_skb(skb);
                return NETDEV_TX_OK;
        }

        return dsa_enqueue_skb(nskb, dev);
}

/* ethtool operations *******************************************************/

static void dsa_user_get_drvinfo(struct net_device *dev,
                                 struct ethtool_drvinfo *drvinfo)
{
        strscpy(drvinfo->driver, "dsa", sizeof(drvinfo->driver));
        strscpy(drvinfo->fw_version, "N/A", sizeof(drvinfo->fw_version));
        strscpy(drvinfo->bus_info, "platform", sizeof(drvinfo->bus_info));
}

static int dsa_user_get_regs_len(struct net_device *dev)
{
        struct dsa_port *dp = dsa_user_to_port(dev);
        struct dsa_switch *ds = dp->ds;

        if (ds->ops->get_regs_len)
                return ds->ops->get_regs_len(ds, dp->index);

        return -EOPNOTSUPP;
}

static void
dsa_user_get_regs(struct net_device *dev, struct ethtool_regs *regs, void *_p)
{
        struct dsa_port *dp = dsa_user_to_port(dev);
        struct dsa_switch *ds = dp->ds;

        if (ds->ops->get_regs)
                ds->ops->get_regs(ds, dp->index, regs, _p);
}

static int dsa_user_nway_reset(struct net_device *dev)
{
        struct dsa_port *dp = dsa_user_to_port(dev);

        return phylink_ethtool_nway_reset(dp->pl);
}

static int dsa_user_get_eeprom_len(struct net_device *dev)
{
        struct dsa_port *dp = dsa_user_to_port(dev);
        struct dsa_switch *ds = dp->ds;

        if (ds->cd && ds->cd->eeprom_len)
                return ds->cd->eeprom_len;

        if (ds->ops->get_eeprom_len)
                return ds->ops->get_eeprom_len(ds);

        return 0;
}

static int dsa_user_get_eeprom(struct net_device *dev,
                               struct ethtool_eeprom *eeprom, u8 *data)
{
        struct dsa_port *dp = dsa_user_to_port(dev);
        struct dsa_switch *ds = dp->ds;

        if (ds->ops->get_eeprom)
                return ds->ops->get_eeprom(ds, eeprom, data);

        return -EOPNOTSUPP;
}

static int dsa_user_set_eeprom(struct net_device *dev,
                               struct ethtool_eeprom *eeprom, u8 *data)
{
        struct dsa_port *dp = dsa_user_to_port(dev);
        struct dsa_switch *ds = dp->ds;

        if (ds->ops->set_eeprom)
                return ds->ops->set_eeprom(ds, eeprom, data);

        return -EOPNOTSUPP;
}

static void dsa_user_get_strings(struct net_device *dev,
                                 uint32_t stringset, uint8_t *data)
{
        struct dsa_port *dp = dsa_user_to_port(dev);
        struct dsa_switch *ds = dp->ds;

        if (stringset == ETH_SS_STATS) {
                ethtool_puts(&data, "tx_packets");
                ethtool_puts(&data, "tx_bytes");
                ethtool_puts(&data, "rx_packets");
                ethtool_puts(&data, "rx_bytes");
                if (ds->ops->get_strings)
                        ds->ops->get_strings(ds, dp->index, stringset, data);
        } else if (stringset ==  ETH_SS_TEST) {
                net_selftest_get_strings(data);
        }

}

static void dsa_user_get_ethtool_stats(struct net_device *dev,
                                       struct ethtool_stats *stats,
                                       uint64_t *data)
{
        struct dsa_port *dp = dsa_user_to_port(dev);
        struct dsa_switch *ds = dp->ds;
        struct pcpu_sw_netstats *s;
        unsigned int start;
        int i;

        for_each_possible_cpu(i) {
                u64 tx_packets, tx_bytes, rx_packets, rx_bytes;

                s = per_cpu_ptr(dev->tstats, i);
                do {
                        start = u64_stats_fetch_begin(&s->syncp);
                        tx_packets = u64_stats_read(&s->tx_packets);
                        tx_bytes = u64_stats_read(&s->tx_bytes);
                        rx_packets = u64_stats_read(&s->rx_packets);
                        rx_bytes = u64_stats_read(&s->rx_bytes);
                } while (u64_stats_fetch_retry(&s->syncp, start));
                data[0] += tx_packets;
                data[1] += tx_bytes;
                data[2] += rx_packets;
                data[3] += rx_bytes;
        }
        if (ds->ops->get_ethtool_stats)
                ds->ops->get_ethtool_stats(ds, dp->index, data + 4);
}

static int dsa_user_get_sset_count(struct net_device *dev, int sset)
{
        struct dsa_port *dp = dsa_user_to_port(dev);
        struct dsa_switch *ds = dp->ds;

        if (sset == ETH_SS_STATS) {
                int count = 0;

                if (ds->ops->get_sset_count) {
                        count = ds->ops->get_sset_count(ds, dp->index, sset);
                        if (count < 0)
                                return count;
                }

                return count + 4;
        } else if (sset ==  ETH_SS_TEST) {
                return net_selftest_get_count();
        }

        return -EOPNOTSUPP;
}

static void dsa_user_get_eth_phy_stats(struct net_device *dev,
                                       struct ethtool_eth_phy_stats *phy_stats)
{
        struct dsa_port *dp = dsa_user_to_port(dev);
        struct dsa_switch *ds = dp->ds;

        if (ds->ops->get_eth_phy_stats)
                ds->ops->get_eth_phy_stats(ds, dp->index, phy_stats);
}

static void dsa_user_get_eth_mac_stats(struct net_device *dev,
                                       struct ethtool_eth_mac_stats *mac_stats)
{
        struct dsa_port *dp = dsa_user_to_port(dev);
        struct dsa_switch *ds = dp->ds;

        if (ds->ops->get_eth_mac_stats)
                ds->ops->get_eth_mac_stats(ds, dp->index, mac_stats);
}

static void
dsa_user_get_eth_ctrl_stats(struct net_device *dev,
                            struct ethtool_eth_ctrl_stats *ctrl_stats)
{
        struct dsa_port *dp = dsa_user_to_port(dev);
        struct dsa_switch *ds = dp->ds;

        if (ds->ops->get_eth_ctrl_stats)
                ds->ops->get_eth_ctrl_stats(ds, dp->index, ctrl_stats);
}

static void
dsa_user_get_rmon_stats(struct net_device *dev,
                        struct ethtool_rmon_stats *rmon_stats,
                        const struct ethtool_rmon_hist_range **ranges)
{
        struct dsa_port *dp = dsa_user_to_port(dev);
        struct dsa_switch *ds = dp->ds;

        if (ds->ops->get_rmon_stats)
                ds->ops->get_rmon_stats(ds, dp->index, rmon_stats, ranges);
}

static void dsa_user_get_ts_stats(struct net_device *dev,
                                  struct ethtool_ts_stats *ts_stats)
{
        struct dsa_port *dp = dsa_user_to_port(dev);
        struct dsa_switch *ds = dp->ds;

        if (ds->ops->get_ts_stats)
                ds->ops->get_ts_stats(ds, dp->index, ts_stats);
}

static void dsa_user_net_selftest(struct net_device *ndev,
                                  struct ethtool_test *etest, u64 *buf)
{
        struct dsa_port *dp = dsa_user_to_port(ndev);
        struct dsa_switch *ds = dp->ds;

        if (ds->ops->self_test) {
                ds->ops->self_test(ds, dp->index, etest, buf);
                return;
        }

        net_selftest(ndev, etest, buf);
}

static int dsa_user_get_mm(struct net_device *dev,
                           struct ethtool_mm_state *state)
{
        struct dsa_port *dp = dsa_user_to_port(dev);
        struct dsa_switch *ds = dp->ds;

        if (!ds->ops->get_mm)
                return -EOPNOTSUPP;

        return ds->ops->get_mm(ds, dp->index, state);
}

static int dsa_user_set_mm(struct net_device *dev, struct ethtool_mm_cfg *cfg,
                           struct netlink_ext_ack *extack)
{
        struct dsa_port *dp = dsa_user_to_port(dev);
        struct dsa_switch *ds = dp->ds;

        if (!ds->ops->set_mm)
                return -EOPNOTSUPP;

        return ds->ops->set_mm(ds, dp->index, cfg, extack);
}

static void dsa_user_get_mm_stats(struct net_device *dev,
                                  struct ethtool_mm_stats *stats)
{
        struct dsa_port *dp = dsa_user_to_port(dev);
        struct dsa_switch *ds = dp->ds;

        if (ds->ops->get_mm_stats)
                ds->ops->get_mm_stats(ds, dp->index, stats);
}

static void dsa_user_get_wol(struct net_device *dev, struct ethtool_wolinfo *w)
{
        struct dsa_port *dp = dsa_user_to_port(dev);
        struct dsa_switch *ds = dp->ds;

        phylink_ethtool_get_wol(dp->pl, w);

        if (ds->ops->get_wol)
                ds->ops->get_wol(ds, dp->index, w);
}

static int dsa_user_set_wol(struct net_device *dev, struct ethtool_wolinfo *w)
{
        struct dsa_port *dp = dsa_user_to_port(dev);
        struct dsa_switch *ds = dp->ds;
        int ret = -EOPNOTSUPP;

        phylink_ethtool_set_wol(dp->pl, w);

        if (ds->ops->set_wol)
                ret = ds->ops->set_wol(ds, dp->index, w);

        return ret;
}

static int dsa_user_set_eee(struct net_device *dev, struct ethtool_keee *e)
{
        struct dsa_port *dp = dsa_user_to_port(dev);
        struct dsa_switch *ds = dp->ds;
        int ret;

        /* Check whether the switch supports EEE */
        if (!ds->ops->support_eee || !ds->ops->support_eee(ds, dp->index))
                return -EOPNOTSUPP;

        /* If the port is using phylink managed EEE, then an unimplemented
         * set_mac_eee() is permissible.
         */
        if (!phylink_mac_implements_lpi(ds->phylink_mac_ops)) {
                /* Port's PHY and MAC both need to be EEE capable */
                if (!dev->phydev)
                        return -ENODEV;

                if (!ds->ops->set_mac_eee)
                        return -EOPNOTSUPP;

                ret = ds->ops->set_mac_eee(ds, dp->index, e);
                if (ret)
                        return ret;
        } else if (ds->ops->set_mac_eee) {
                ret = ds->ops->set_mac_eee(ds, dp->index, e);
                if (ret)
                        return ret;
        }

        return phylink_ethtool_set_eee(dp->pl, e);
}

static int dsa_user_get_eee(struct net_device *dev, struct ethtool_keee *e)
{
        struct dsa_port *dp = dsa_user_to_port(dev);
        struct dsa_switch *ds = dp->ds;

        /* Check whether the switch supports EEE */
        if (!ds->ops->support_eee || !ds->ops->support_eee(ds, dp->index))
                return -EOPNOTSUPP;

        /* Port's PHY and MAC both need to be EEE capable */
        if (!dev->phydev)
                return -ENODEV;

        return phylink_ethtool_get_eee(dp->pl, e);
}

static int dsa_user_get_link_ksettings(struct net_device *dev,
                                       struct ethtool_link_ksettings *cmd)
{
        struct dsa_port *dp = dsa_user_to_port(dev);

        return phylink_ethtool_ksettings_get(dp->pl, cmd);
}

static int dsa_user_set_link_ksettings(struct net_device *dev,
                                       const struct ethtool_link_ksettings *cmd)
{
        struct dsa_port *dp = dsa_user_to_port(dev);

        return phylink_ethtool_ksettings_set(dp->pl, cmd);
}

static void dsa_user_get_pause_stats(struct net_device *dev,
                                     struct ethtool_pause_stats *pause_stats)
{
        struct dsa_port *dp = dsa_user_to_port(dev);
        struct dsa_switch *ds = dp->ds;

        if (ds->ops->get_pause_stats)
                ds->ops->get_pause_stats(ds, dp->index, pause_stats);
}

static void dsa_user_get_pauseparam(struct net_device *dev,
                                    struct ethtool_pauseparam *pause)
{
        struct dsa_port *dp = dsa_user_to_port(dev);

        phylink_ethtool_get_pauseparam(dp->pl, pause);
}

static int dsa_user_set_pauseparam(struct net_device *dev,
                                   struct ethtool_pauseparam *pause)
{
        struct dsa_port *dp = dsa_user_to_port(dev);

        return phylink_ethtool_set_pauseparam(dp->pl, pause);
}

#ifdef CONFIG_NET_POLL_CONTROLLER
static int dsa_user_netpoll_setup(struct net_device *dev)
{
        struct net_device *conduit = dsa_user_to_conduit(dev);
        struct dsa_user_priv *p = netdev_priv(dev);
        struct netpoll *netpoll;
        int err = 0;

        netpoll = kzalloc_obj(*netpoll);
        if (!netpoll)
                return -ENOMEM;

        err = __netpoll_setup(netpoll, conduit);
        if (err) {
                kfree(netpoll);
                goto out;
        }

        p->netpoll = netpoll;
out:
        return err;
}

static void dsa_user_netpoll_cleanup(struct net_device *dev)
{
        struct dsa_user_priv *p = netdev_priv(dev);
        struct netpoll *netpoll = p->netpoll;

        if (!netpoll)
                return;

        p->netpoll = NULL;

        __netpoll_free(netpoll);
}

static void dsa_user_poll_controller(struct net_device *dev)
{
}
#endif

static struct dsa_mall_tc_entry *
dsa_user_mall_tc_entry_find(struct net_device *dev, unsigned long cookie)
{
        struct dsa_user_priv *p = netdev_priv(dev);
        struct dsa_mall_tc_entry *mall_tc_entry;

        list_for_each_entry(mall_tc_entry, &p->mall_tc_list, list)
                if (mall_tc_entry->cookie == cookie)
                        return mall_tc_entry;

        return NULL;
}

static int
dsa_user_add_cls_matchall_mirred(struct net_device *dev,
                                 struct tc_cls_matchall_offload *cls,
                                 bool ingress, bool ingress_target)
{
        struct netlink_ext_ack *extack = cls->common.extack;
        struct dsa_port *dp = dsa_user_to_port(dev);
        struct dsa_user_priv *p = netdev_priv(dev);
        struct dsa_mall_mirror_tc_entry *mirror;
        struct dsa_mall_tc_entry *mall_tc_entry;
        struct dsa_switch *ds = dp->ds;
        struct flow_action_entry *act;
        struct dsa_port *to_dp;
        int err;

        if (cls->common.protocol != htons(ETH_P_ALL)) {
                NL_SET_ERR_MSG_MOD(extack,
                                   "Can only offload \"protocol all\" matchall filter");
                return -EOPNOTSUPP;
        }

        if (!ds->ops->port_mirror_add) {
                NL_SET_ERR_MSG_MOD(extack,
                                   "Switch does not support mirroring operation");
                return -EOPNOTSUPP;
        }

        if (!flow_action_basic_hw_stats_check(&cls->rule->action, extack))
                return -EOPNOTSUPP;

        act = &cls->rule->action.entries[0];

        if (!act->dev)
                return -EINVAL;

        if (dsa_user_dev_check(act->dev)) {
                if (ingress_target) {
                        /* We can only fulfill this using software assist */
                        if (cls->common.skip_sw) {
                                NL_SET_ERR_MSG_MOD(extack,
                                                   "Can only mirred to ingress of DSA user port if filter also runs in software");
                                return -EOPNOTSUPP;
                        }
                        to_dp = dp->cpu_dp;
                } else {
                        to_dp = dsa_user_to_port(act->dev);
                }
        } else {
                /* Handle mirroring to foreign target ports as a mirror towards
                 * the CPU. The software tc rule will take the packets from
                 * there.
                 */
                if (cls->common.skip_sw) {
                        NL_SET_ERR_MSG_MOD(extack,
                                           "Can only mirred to CPU if filter also runs in software");
                        return -EOPNOTSUPP;
                }
                to_dp = dp->cpu_dp;
        }

        if (dp->ds != to_dp->ds) {
                NL_SET_ERR_MSG_MOD(extack,
                                   "Cross-chip mirroring not implemented");
                return -EOPNOTSUPP;
        }

        mall_tc_entry = kzalloc_obj(*mall_tc_entry);
        if (!mall_tc_entry)
                return -ENOMEM;

        mall_tc_entry->cookie = cls->cookie;
        mall_tc_entry->type = DSA_PORT_MALL_MIRROR;
        mirror = &mall_tc_entry->mirror;
        mirror->to_local_port = to_dp->index;
        mirror->ingress = ingress;

        err = ds->ops->port_mirror_add(ds, dp->index, mirror, ingress, extack);
        if (err) {
                kfree(mall_tc_entry);
                return err;
        }

        list_add_tail(&mall_tc_entry->list, &p->mall_tc_list);

        return err;
}

static int
dsa_user_add_cls_matchall_police(struct net_device *dev,
                                 struct tc_cls_matchall_offload *cls,
                                 bool ingress)
{
        struct netlink_ext_ack *extack = cls->common.extack;
        struct dsa_port *dp = dsa_user_to_port(dev);
        struct dsa_user_priv *p = netdev_priv(dev);
        struct dsa_mall_tc_entry *mall_tc_entry;
        struct flow_action_police *policer;
        struct dsa_switch *ds = dp->ds;
        struct flow_action_entry *act;
        int err;

        if (!ds->ops->port_policer_add) {
                NL_SET_ERR_MSG_MOD(extack,
                                   "Policing offload not implemented");
                return -EOPNOTSUPP;
        }

        if (!ingress) {
                NL_SET_ERR_MSG_MOD(extack,
                                   "Only supported on ingress qdisc");
                return -EOPNOTSUPP;
        }

        if (!flow_action_basic_hw_stats_check(&cls->rule->action, extack))
                return -EOPNOTSUPP;

        list_for_each_entry(mall_tc_entry, &p->mall_tc_list, list) {
                if (mall_tc_entry->type == DSA_PORT_MALL_POLICER) {
                        NL_SET_ERR_MSG_MOD(extack,
                                           "Only one port policer allowed");
                        return -EEXIST;
                }
        }

        act = &cls->rule->action.entries[0];

        mall_tc_entry = kzalloc_obj(*mall_tc_entry);
        if (!mall_tc_entry)
                return -ENOMEM;

        mall_tc_entry->cookie = cls->cookie;
        mall_tc_entry->type = DSA_PORT_MALL_POLICER;
        policer = &mall_tc_entry->policer;
        *policer = act->police;

        err = ds->ops->port_policer_add(ds, dp->index, policer);
        if (err) {
                kfree(mall_tc_entry);
                return err;
        }

        list_add_tail(&mall_tc_entry->list, &p->mall_tc_list);

        return err;
}

static int dsa_user_add_cls_matchall(struct net_device *dev,
                                     struct tc_cls_matchall_offload *cls,
                                     bool ingress)
{
        const struct flow_action *action = &cls->rule->action;
        struct netlink_ext_ack *extack = cls->common.extack;

        if (!flow_offload_has_one_action(action)) {
                NL_SET_ERR_MSG_MOD(extack,
                                   "Cannot offload matchall filter with more than one action");
                return -EOPNOTSUPP;
        }

        switch (action->entries[0].id) {
        case FLOW_ACTION_MIRRED:
                return dsa_user_add_cls_matchall_mirred(dev, cls, ingress,
                                                        false);
        case FLOW_ACTION_MIRRED_INGRESS:
                return dsa_user_add_cls_matchall_mirred(dev, cls, ingress,
                                                        true);
        case FLOW_ACTION_POLICE:
                return dsa_user_add_cls_matchall_police(dev, cls, ingress);
        default:
                NL_SET_ERR_MSG_MOD(extack, "Unknown action");
                break;
        }

        return -EOPNOTSUPP;
}

static void dsa_user_del_cls_matchall(struct net_device *dev,
                                      struct tc_cls_matchall_offload *cls)
{
        struct dsa_port *dp = dsa_user_to_port(dev);
        struct dsa_mall_tc_entry *mall_tc_entry;
        struct dsa_switch *ds = dp->ds;

        mall_tc_entry = dsa_user_mall_tc_entry_find(dev, cls->cookie);
        if (!mall_tc_entry)
                return;

        list_del(&mall_tc_entry->list);

        switch (mall_tc_entry->type) {
        case DSA_PORT_MALL_MIRROR:
                if (ds->ops->port_mirror_del)
                        ds->ops->port_mirror_del(ds, dp->index,
                                                 &mall_tc_entry->mirror);
                break;
        case DSA_PORT_MALL_POLICER:
                if (ds->ops->port_policer_del)
                        ds->ops->port_policer_del(ds, dp->index);
                break;
        default:
                WARN_ON(1);
        }

        kfree(mall_tc_entry);
}

static int dsa_user_setup_tc_cls_matchall(struct net_device *dev,
                                          struct tc_cls_matchall_offload *cls,
                                          bool ingress)
{
        if (cls->common.chain_index)
                return -EOPNOTSUPP;

        switch (cls->command) {
        case TC_CLSMATCHALL_REPLACE:
                return dsa_user_add_cls_matchall(dev, cls, ingress);
        case TC_CLSMATCHALL_DESTROY:
                dsa_user_del_cls_matchall(dev, cls);
                return 0;
        default:
                return -EOPNOTSUPP;
        }
}

static int dsa_user_add_cls_flower(struct net_device *dev,
                                   struct flow_cls_offload *cls,
                                   bool ingress)
{
        struct dsa_port *dp = dsa_user_to_port(dev);
        struct dsa_switch *ds = dp->ds;
        int port = dp->index;

        if (!ds->ops->cls_flower_add)
                return -EOPNOTSUPP;

        return ds->ops->cls_flower_add(ds, port, cls, ingress);
}

static int dsa_user_del_cls_flower(struct net_device *dev,
                                   struct flow_cls_offload *cls,
                                   bool ingress)
{
        struct dsa_port *dp = dsa_user_to_port(dev);
        struct dsa_switch *ds = dp->ds;
        int port = dp->index;

        if (!ds->ops->cls_flower_del)
                return -EOPNOTSUPP;

        return ds->ops->cls_flower_del(ds, port, cls, ingress);
}

static int dsa_user_stats_cls_flower(struct net_device *dev,
                                     struct flow_cls_offload *cls,
                                     bool ingress)
{
        struct dsa_port *dp = dsa_user_to_port(dev);
        struct dsa_switch *ds = dp->ds;
        int port = dp->index;

        if (!ds->ops->cls_flower_stats)
                return -EOPNOTSUPP;

        return ds->ops->cls_flower_stats(ds, port, cls, ingress);
}

static int dsa_user_setup_tc_cls_flower(struct net_device *dev,
                                        struct flow_cls_offload *cls,
                                        bool ingress)
{
        switch (cls->command) {
        case FLOW_CLS_REPLACE:
                return dsa_user_add_cls_flower(dev, cls, ingress);
        case FLOW_CLS_DESTROY:
                return dsa_user_del_cls_flower(dev, cls, ingress);
        case FLOW_CLS_STATS:
                return dsa_user_stats_cls_flower(dev, cls, ingress);
        default:
                return -EOPNOTSUPP;
        }
}

static int dsa_user_setup_tc_block_cb(enum tc_setup_type type, void *type_data,
                                      void *cb_priv, bool ingress)
{
        struct net_device *dev = cb_priv;

        if (!tc_can_offload(dev))
                return -EOPNOTSUPP;

        switch (type) {
        case TC_SETUP_CLSMATCHALL:
                return dsa_user_setup_tc_cls_matchall(dev, type_data, ingress);
        case TC_SETUP_CLSFLOWER:
                return dsa_user_setup_tc_cls_flower(dev, type_data, ingress);
        default:
                return -EOPNOTSUPP;
        }
}

static int dsa_user_setup_tc_block_cb_ig(enum tc_setup_type type,
                                         void *type_data, void *cb_priv)
{
        return dsa_user_setup_tc_block_cb(type, type_data, cb_priv, true);
}

static int dsa_user_setup_tc_block_cb_eg(enum tc_setup_type type,
                                         void *type_data, void *cb_priv)
{
        return dsa_user_setup_tc_block_cb(type, type_data, cb_priv, false);
}

static LIST_HEAD(dsa_user_block_cb_list);

static int dsa_user_setup_tc_block(struct net_device *dev,
                                   struct flow_block_offload *f)
{
        struct flow_block_cb *block_cb;
        flow_setup_cb_t *cb;

        if (f->binder_type == FLOW_BLOCK_BINDER_TYPE_CLSACT_INGRESS)
                cb = dsa_user_setup_tc_block_cb_ig;
        else if (f->binder_type == FLOW_BLOCK_BINDER_TYPE_CLSACT_EGRESS)
                cb = dsa_user_setup_tc_block_cb_eg;
        else
                return -EOPNOTSUPP;

        f->driver_block_list = &dsa_user_block_cb_list;

        switch (f->command) {
        case FLOW_BLOCK_BIND:
                if (flow_block_cb_is_busy(cb, dev, &dsa_user_block_cb_list))
                        return -EBUSY;

                block_cb = flow_block_cb_alloc(cb, dev, dev, NULL);
                if (IS_ERR(block_cb))
                        return PTR_ERR(block_cb);

                flow_block_cb_add(block_cb, f);
                list_add_tail(&block_cb->driver_list, &dsa_user_block_cb_list);
                return 0;
        case FLOW_BLOCK_UNBIND:
                block_cb = flow_block_cb_lookup(f->block, cb, dev);
                if (!block_cb)
                        return -ENOENT;

                flow_block_cb_remove(block_cb, f);
                list_del(&block_cb->driver_list);
                return 0;
        default:
                return -EOPNOTSUPP;
        }
}

static int dsa_user_setup_ft_block(struct dsa_switch *ds, int port,
                                   void *type_data)
{
        struct net_device *conduit = dsa_port_to_conduit(dsa_to_port(ds, port));

        if (!conduit->netdev_ops->ndo_setup_tc)
                return -EOPNOTSUPP;

        return conduit->netdev_ops->ndo_setup_tc(conduit, TC_SETUP_FT, type_data);
}

static int dsa_user_setup_tc(struct net_device *dev, enum tc_setup_type type,
                             void *type_data)
{
        struct dsa_port *dp = dsa_user_to_port(dev);
        struct dsa_switch *ds = dp->ds;

        switch (type) {
        case TC_SETUP_BLOCK:
                return dsa_user_setup_tc_block(dev, type_data);
        case TC_SETUP_FT:
                return dsa_user_setup_ft_block(ds, dp->index, type_data);
        default:
                break;
        }

        if (!ds->ops->port_setup_tc)
                return -EOPNOTSUPP;

        return ds->ops->port_setup_tc(ds, dp->index, type, type_data);
}

static int dsa_user_get_rxnfc(struct net_device *dev,
                              struct ethtool_rxnfc *nfc, u32 *rule_locs)
{
        struct dsa_port *dp = dsa_user_to_port(dev);
        struct dsa_switch *ds = dp->ds;

        if (!ds->ops->get_rxnfc)
                return -EOPNOTSUPP;

        return ds->ops->get_rxnfc(ds, dp->index, nfc, rule_locs);
}

static int dsa_user_set_rxnfc(struct net_device *dev,
                              struct ethtool_rxnfc *nfc)
{
        struct dsa_port *dp = dsa_user_to_port(dev);
        struct dsa_switch *ds = dp->ds;

        if (!ds->ops->set_rxnfc)
                return -EOPNOTSUPP;

        return ds->ops->set_rxnfc(ds, dp->index, nfc);
}

static int dsa_user_get_ts_info(struct net_device *dev,
                                struct kernel_ethtool_ts_info *ts)
{
        struct dsa_user_priv *p = netdev_priv(dev);
        struct dsa_switch *ds = p->dp->ds;

        if (!ds->ops->get_ts_info)
                return -EOPNOTSUPP;

        return ds->ops->get_ts_info(ds, p->dp->index, ts);
}

static int dsa_user_vlan_rx_add_vid(struct net_device *dev, __be16 proto,
                                    u16 vid)
{
        struct dsa_port *dp = dsa_user_to_port(dev);
        struct switchdev_obj_port_vlan vlan = {
                .obj.id = SWITCHDEV_OBJ_ID_PORT_VLAN,
                .vid = vid,
                /* This API only allows programming tagged, non-PVID VIDs */
                .flags = 0,
        };
        struct netlink_ext_ack extack = {0};
        struct dsa_switch *ds = dp->ds;
        struct netdev_hw_addr *ha;
        struct dsa_vlan *v;
        int ret;

        /* User port... */
        ret = dsa_port_vlan_add(dp, &vlan, &extack);
        if (ret) {
                if (extack._msg)
                        netdev_err(dev, "%s\n", extack._msg);
                return ret;
        }

        /* And CPU port... */
        ret = dsa_port_host_vlan_add(dp, &vlan, &extack);
        if (ret) {
                if (extack._msg)
                        netdev_err(dev, "CPU port %d: %s\n", dp->cpu_dp->index,
                                   extack._msg);
                return ret;
        }

        if (!dsa_switch_supports_uc_filtering(ds) &&
            !dsa_switch_supports_mc_filtering(ds))
                return 0;

        v = kzalloc_obj(*v);
        if (!v) {
                ret = -ENOMEM;
                goto rollback;
        }

        netif_addr_lock_bh(dev);

        v->vid = vid;
        list_add_tail(&v->list, &dp->user_vlans);

        if (dsa_switch_supports_mc_filtering(ds)) {
                netdev_for_each_synced_mc_addr(ha, dev) {
                        dsa_user_schedule_standalone_work(dev, DSA_MC_ADD,
                                                          ha->addr, vid);
                }
        }

        if (dsa_switch_supports_uc_filtering(ds)) {
                netdev_for_each_synced_uc_addr(ha, dev) {
                        dsa_user_schedule_standalone_work(dev, DSA_UC_ADD,
                                                          ha->addr, vid);
                }
        }

        netif_addr_unlock_bh(dev);

        dsa_flush_workqueue();

        return 0;

rollback:
        dsa_port_host_vlan_del(dp, &vlan);
        dsa_port_vlan_del(dp, &vlan);

        return ret;
}

static int dsa_user_vlan_rx_kill_vid(struct net_device *dev, __be16 proto,
                                     u16 vid)
{
        struct dsa_port *dp = dsa_user_to_port(dev);
        struct switchdev_obj_port_vlan vlan = {
                .vid = vid,
                /* This API only allows programming tagged, non-PVID VIDs */
                .flags = 0,
        };
        struct dsa_switch *ds = dp->ds;
        struct netdev_hw_addr *ha;
        struct dsa_vlan *v;
        int err;

        err = dsa_port_vlan_del(dp, &vlan);
        if (err)
                return err;

        err = dsa_port_host_vlan_del(dp, &vlan);
        if (err)
                return err;

        if (!dsa_switch_supports_uc_filtering(ds) &&
            !dsa_switch_supports_mc_filtering(ds))
                return 0;

        netif_addr_lock_bh(dev);

        v = dsa_vlan_find(&dp->user_vlans, &vlan);
        if (!v) {
                netif_addr_unlock_bh(dev);
                return -ENOENT;
        }

        list_del(&v->list);
        kfree(v);

        if (dsa_switch_supports_mc_filtering(ds)) {
                netdev_for_each_synced_mc_addr(ha, dev) {
                        dsa_user_schedule_standalone_work(dev, DSA_MC_DEL,
                                                          ha->addr, vid);
                }
        }

        if (dsa_switch_supports_uc_filtering(ds)) {
                netdev_for_each_synced_uc_addr(ha, dev) {
                        dsa_user_schedule_standalone_work(dev, DSA_UC_DEL,
                                                          ha->addr, vid);
                }
        }

        netif_addr_unlock_bh(dev);

        dsa_flush_workqueue();

        return 0;
}

static int dsa_user_restore_vlan(struct net_device *vdev, int vid, void *arg)
{
        __be16 proto = vdev ? vlan_dev_vlan_proto(vdev) : htons(ETH_P_8021Q);

        return dsa_user_vlan_rx_add_vid(arg, proto, vid);
}

static int dsa_user_clear_vlan(struct net_device *vdev, int vid, void *arg)
{
        __be16 proto = vdev ? vlan_dev_vlan_proto(vdev) : htons(ETH_P_8021Q);

        return dsa_user_vlan_rx_kill_vid(arg, proto, vid);
}

/* Keep the VLAN RX filtering list in sync with the hardware only if VLAN
 * filtering is enabled. The baseline is that only ports that offload a
 * VLAN-aware bridge are VLAN-aware, and standalone ports are VLAN-unaware,
 * but there are exceptions for quirky hardware.
 *
 * If ds->vlan_filtering_is_global = true, then standalone ports which share
 * the same switch with other ports that offload a VLAN-aware bridge are also
 * inevitably VLAN-aware.
 *
 * To summarize, a DSA switch port offloads:
 *
 * - If standalone (this includes software bridge, software LAG):
 *     - if ds->needs_standalone_vlan_filtering = true, OR if
 *       (ds->vlan_filtering_is_global = true AND there are bridges spanning
 *       this switch chip which have vlan_filtering=1)
 *         - the 8021q upper VLANs
 *     - else (standalone VLAN filtering is not needed, VLAN filtering is not
 *       global, or it is, but no port is under a VLAN-aware bridge):
 *         - no VLAN (any 8021q upper is a software VLAN)
 *
 * - If under a vlan_filtering=0 bridge which it offload:
 *     - if ds->configure_vlan_while_not_filtering = true (default):
 *         - the bridge VLANs. These VLANs are committed to hardware but inactive.
 *     - else (deprecated):
 *         - no VLAN. The bridge VLANs are not restored when VLAN awareness is
 *           enabled, so this behavior is broken and discouraged.
 *
 * - If under a vlan_filtering=1 bridge which it offload:
 *     - the bridge VLANs
 *     - the 8021q upper VLANs
 */
int dsa_user_manage_vlan_filtering(struct net_device *user,
                                   bool vlan_filtering)
{
        int err;

        if (vlan_filtering) {
                user->features |= NETIF_F_HW_VLAN_CTAG_FILTER;

                err = vlan_for_each(user, dsa_user_restore_vlan, user);
                if (err) {
                        vlan_for_each(user, dsa_user_clear_vlan, user);
                        user->features &= ~NETIF_F_HW_VLAN_CTAG_FILTER;
                        return err;
                }
        } else {
                err = vlan_for_each(user, dsa_user_clear_vlan, user);
                if (err)
                        return err;

                user->features &= ~NETIF_F_HW_VLAN_CTAG_FILTER;
        }

        return 0;
}

struct dsa_hw_port {
        struct list_head list;
        struct net_device *dev;
        int old_mtu;
};

static int dsa_hw_port_list_set_mtu(struct list_head *hw_port_list, int mtu)
{
        const struct dsa_hw_port *p;
        int err;

        list_for_each_entry(p, hw_port_list, list) {
                if (p->dev->mtu == mtu)
                        continue;

                err = dev_set_mtu(p->dev, mtu);
                if (err)
                        goto rollback;
        }

        return 0;

rollback:
        list_for_each_entry_continue_reverse(p, hw_port_list, list) {
                if (p->dev->mtu == p->old_mtu)
                        continue;

                if (dev_set_mtu(p->dev, p->old_mtu))
                        netdev_err(p->dev, "Failed to restore MTU\n");
        }

        return err;
}

static void dsa_hw_port_list_free(struct list_head *hw_port_list)
{
        struct dsa_hw_port *p, *n;

        list_for_each_entry_safe(p, n, hw_port_list, list)
                kfree(p);
}

/* Make the hardware datapath to/from @dev limited to a common MTU */
static void dsa_bridge_mtu_normalization(struct dsa_port *dp)
{
        struct list_head hw_port_list;
        struct dsa_switch_tree *dst;
        int min_mtu = ETH_MAX_MTU;
        struct dsa_port *other_dp;
        int err;

        if (!dp->ds->mtu_enforcement_ingress)
                return;

        if (!dp->bridge)
                return;

        INIT_LIST_HEAD(&hw_port_list);

        /* Populate the list of ports that are part of the same bridge
         * as the newly added/modified port
         */
        list_for_each_entry(dst, &dsa_tree_list, list) {
                list_for_each_entry(other_dp, &dst->ports, list) {
                        struct dsa_hw_port *hw_port;
                        struct net_device *user;

                        if (other_dp->type != DSA_PORT_TYPE_USER)
                                continue;

                        if (!dsa_port_bridge_same(dp, other_dp))
                                continue;

                        if (!other_dp->ds->mtu_enforcement_ingress)
                                continue;

                        user = other_dp->user;

                        if (min_mtu > user->mtu)
                                min_mtu = user->mtu;

                        hw_port = kzalloc_obj(*hw_port);
                        if (!hw_port)
                                goto out;

                        hw_port->dev = user;
                        hw_port->old_mtu = user->mtu;

                        list_add(&hw_port->list, &hw_port_list);
                }
        }

        /* Attempt to configure the entire hardware bridge to the newly added
         * interface's MTU first, regardless of whether the intention of the
         * user was to raise or lower it.
         */
        err = dsa_hw_port_list_set_mtu(&hw_port_list, dp->user->mtu);
        if (!err)
                goto out;

        /* Clearly that didn't work out so well, so just set the minimum MTU on
         * all hardware bridge ports now. If this fails too, then all ports will
         * still have their old MTU rolled back anyway.
         */
        dsa_hw_port_list_set_mtu(&hw_port_list, min_mtu);

out:
        dsa_hw_port_list_free(&hw_port_list);
}

int dsa_user_change_mtu(struct net_device *dev, int new_mtu)
{
        struct net_device *conduit = dsa_user_to_conduit(dev);
        struct dsa_port *dp = dsa_user_to_port(dev);
        struct dsa_port *cpu_dp = dp->cpu_dp;
        struct dsa_switch *ds = dp->ds;
        struct dsa_port *other_dp;
        int largest_mtu = 0;
        int new_conduit_mtu;
        int old_conduit_mtu;
        int mtu_limit;
        int overhead;
        int cpu_mtu;
        int err;

        if (!ds->ops->port_change_mtu)
                return -EOPNOTSUPP;

        dsa_tree_for_each_user_port(other_dp, ds->dst) {
                int user_mtu;

                /* During probe, this function will be called for each user
                 * device, while not all of them have been allocated. That's
                 * ok, it doesn't change what the maximum is, so ignore it.
                 */
                if (!other_dp->user)
                        continue;

                /* Pretend that we already applied the setting, which we
                 * actually haven't (still haven't done all integrity checks)
                 */
                if (dp == other_dp)
                        user_mtu = new_mtu;
                else
                        user_mtu = other_dp->user->mtu;

                if (largest_mtu < user_mtu)
                        largest_mtu = user_mtu;
        }

        overhead = dsa_tag_protocol_overhead(cpu_dp->tag_ops);
        mtu_limit = min_t(int, conduit->max_mtu, dev->max_mtu + overhead);
        old_conduit_mtu = conduit->mtu;
        new_conduit_mtu = largest_mtu + overhead;
        if (new_conduit_mtu > mtu_limit)
                return -ERANGE;

        /* If the conduit MTU isn't over limit, there's no need to check the CPU
         * MTU, since that surely isn't either.
         */
        cpu_mtu = largest_mtu;

        /* Start applying stuff */
        if (new_conduit_mtu != old_conduit_mtu) {
                err = dev_set_mtu(conduit, new_conduit_mtu);
                if (err < 0)
                        goto out_conduit_failed;

                /* We only need to propagate the MTU of the CPU port to
                 * upstream switches, so emit a notifier which updates them.
                 */
                err = dsa_port_mtu_change(cpu_dp, cpu_mtu);
                if (err)
                        goto out_cpu_failed;
        }

        err = ds->ops->port_change_mtu(ds, dp->index, new_mtu);
        if (err)
                goto out_port_failed;

        WRITE_ONCE(dev->mtu, new_mtu);

        dsa_bridge_mtu_normalization(dp);

        return 0;

out_port_failed:
        if (new_conduit_mtu != old_conduit_mtu)
                dsa_port_mtu_change(cpu_dp, old_conduit_mtu - overhead);
out_cpu_failed:
        if (new_conduit_mtu != old_conduit_mtu)
                dev_set_mtu(conduit, old_conduit_mtu);
out_conduit_failed:
        return err;
}

static int __maybe_unused
dsa_user_dcbnl_set_apptrust(struct net_device *dev, u8 *sel, int nsel)
{
        struct dsa_port *dp = dsa_user_to_port(dev);
        struct dsa_switch *ds = dp->ds;
        int port = dp->index;

        if (!ds->ops->port_set_apptrust)
                return -EOPNOTSUPP;

        return ds->ops->port_set_apptrust(ds, port, sel, nsel);
}

static int __maybe_unused
dsa_user_dcbnl_get_apptrust(struct net_device *dev, u8 *sel, int *nsel)
{
        struct dsa_port *dp = dsa_user_to_port(dev);
        struct dsa_switch *ds = dp->ds;
        int port = dp->index;

        if (!ds->ops->port_get_apptrust)
                return -EOPNOTSUPP;

        return ds->ops->port_get_apptrust(ds, port, sel, nsel);
}

static int __maybe_unused
dsa_user_dcbnl_set_default_prio(struct net_device *dev, struct dcb_app *app)
{
        struct dsa_port *dp = dsa_user_to_port(dev);
        struct dsa_switch *ds = dp->ds;
        unsigned long mask, new_prio;
        int err, port = dp->index;

        if (!ds->ops->port_set_default_prio)
                return -EOPNOTSUPP;

        err = dcb_ieee_setapp(dev, app);
        if (err)
                return err;

        mask = dcb_ieee_getapp_mask(dev, app);
        new_prio = __fls(mask);

        err = ds->ops->port_set_default_prio(ds, port, new_prio);
        if (err) {
                dcb_ieee_delapp(dev, app);
                return err;
        }

        return 0;
}

/* Update the DSCP prio entries on all user ports of the switch in case
 * the switch supports global DSCP prio instead of per port DSCP prios.
 */
static int dsa_user_dcbnl_ieee_global_dscp_setdel(struct net_device *dev,
                                                  struct dcb_app *app, bool del)
{
        int (*setdel)(struct net_device *dev, struct dcb_app *app);
        struct dsa_port *dp = dsa_user_to_port(dev);
        struct dsa_switch *ds = dp->ds;
        struct dsa_port *other_dp;
        int err, restore_err;

        if (del)
                setdel = dcb_ieee_delapp;
        else
                setdel = dcb_ieee_setapp;

        dsa_switch_for_each_user_port(other_dp, ds) {
                struct net_device *user = other_dp->user;

                if (!user || user == dev)
                        continue;

                err = setdel(user, app);
                if (err)
                        goto err_try_to_restore;
        }

        return 0;

err_try_to_restore:

        /* Revert logic to restore previous state of app entries */
        if (!del)
                setdel = dcb_ieee_delapp;
        else
                setdel = dcb_ieee_setapp;

        dsa_switch_for_each_user_port_continue_reverse(other_dp, ds) {
                struct net_device *user = other_dp->user;

                if (!user || user == dev)
                        continue;

                restore_err = setdel(user, app);
                if (restore_err)
                        netdev_err(user, "Failed to restore DSCP prio entry configuration\n");
        }

        return err;
}

static int __maybe_unused
dsa_user_dcbnl_add_dscp_prio(struct net_device *dev, struct dcb_app *app)
{
        struct dsa_port *dp = dsa_user_to_port(dev);
        struct dsa_switch *ds = dp->ds;
        unsigned long mask, new_prio;
        int err, port = dp->index;
        u8 dscp = app->protocol;

        if (!ds->ops->port_add_dscp_prio)
                return -EOPNOTSUPP;

        if (dscp >= 64) {
                netdev_err(dev, "DSCP APP entry with protocol value %u is invalid\n",
                           dscp);
                return -EINVAL;
        }

        err = dcb_ieee_setapp(dev, app);
        if (err)
                return err;

        mask = dcb_ieee_getapp_mask(dev, app);
        new_prio = __fls(mask);

        err = ds->ops->port_add_dscp_prio(ds, port, dscp, new_prio);
        if (err) {
                dcb_ieee_delapp(dev, app);
                return err;
        }

        if (!ds->dscp_prio_mapping_is_global)
                return 0;

        err = dsa_user_dcbnl_ieee_global_dscp_setdel(dev, app, false);
        if (err) {
                if (ds->ops->port_del_dscp_prio)
                        ds->ops->port_del_dscp_prio(ds, port, dscp, new_prio);
                dcb_ieee_delapp(dev, app);
                return err;
        }

        return 0;
}

static int __maybe_unused dsa_user_dcbnl_ieee_setapp(struct net_device *dev,
                                                     struct dcb_app *app)
{
        switch (app->selector) {
        case IEEE_8021QAZ_APP_SEL_ETHERTYPE:
                switch (app->protocol) {
                case 0:
                        return dsa_user_dcbnl_set_default_prio(dev, app);
                default:
                        return -EOPNOTSUPP;
                }
                break;
        case IEEE_8021QAZ_APP_SEL_DSCP:
                return dsa_user_dcbnl_add_dscp_prio(dev, app);
        default:
                return -EOPNOTSUPP;
        }
}

static int __maybe_unused
dsa_user_dcbnl_del_default_prio(struct net_device *dev, struct dcb_app *app)
{
        struct dsa_port *dp = dsa_user_to_port(dev);
        struct dsa_switch *ds = dp->ds;
        unsigned long mask, new_prio;
        int err, port = dp->index;

        if (!ds->ops->port_set_default_prio)
                return -EOPNOTSUPP;

        err = dcb_ieee_delapp(dev, app);
        if (err)
                return err;

        mask = dcb_ieee_getapp_mask(dev, app);
        new_prio = mask ? __fls(mask) : 0;

        err = ds->ops->port_set_default_prio(ds, port, new_prio);
        if (err) {
                dcb_ieee_setapp(dev, app);
                return err;
        }

        return 0;
}

static int __maybe_unused
dsa_user_dcbnl_del_dscp_prio(struct net_device *dev, struct dcb_app *app)
{
        struct dsa_port *dp = dsa_user_to_port(dev);
        struct dsa_switch *ds = dp->ds;
        int err, port = dp->index;
        u8 dscp = app->protocol;

        if (!ds->ops->port_del_dscp_prio)
                return -EOPNOTSUPP;

        err = dcb_ieee_delapp(dev, app);
        if (err)
                return err;

        err = ds->ops->port_del_dscp_prio(ds, port, dscp, app->priority);
        if (err) {
                dcb_ieee_setapp(dev, app);
                return err;
        }

        if (!ds->dscp_prio_mapping_is_global)
                return 0;

        err = dsa_user_dcbnl_ieee_global_dscp_setdel(dev, app, true);
        if (err) {
                if (ds->ops->port_add_dscp_prio)
                        ds->ops->port_add_dscp_prio(ds, port, dscp,
                                                    app->priority);
                dcb_ieee_setapp(dev, app);
                return err;
        }

        return 0;
}

static int __maybe_unused dsa_user_dcbnl_ieee_delapp(struct net_device *dev,
                                                     struct dcb_app *app)
{
        switch (app->selector) {
        case IEEE_8021QAZ_APP_SEL_ETHERTYPE:
                switch (app->protocol) {
                case 0:
                        return dsa_user_dcbnl_del_default_prio(dev, app);
                default:
                        return -EOPNOTSUPP;
                }
                break;
        case IEEE_8021QAZ_APP_SEL_DSCP:
                return dsa_user_dcbnl_del_dscp_prio(dev, app);
        default:
                return -EOPNOTSUPP;
        }
}

/* Pre-populate the DCB application priority table with the priorities
 * configured during switch setup, which we read from hardware here.
 */
static int dsa_user_dcbnl_init(struct net_device *dev)
{
        struct dsa_port *dp = dsa_user_to_port(dev);
        struct dsa_switch *ds = dp->ds;
        int port = dp->index;
        int err;

        if (ds->ops->port_get_default_prio) {
                int prio = ds->ops->port_get_default_prio(ds, port);
                struct dcb_app app = {
                        .selector = IEEE_8021QAZ_APP_SEL_ETHERTYPE,
                        .protocol = 0,
                        .priority = prio,
                };

                if (prio < 0)
                        return prio;

                err = dcb_ieee_setapp(dev, &app);
                if (err)
                        return err;
        }

        if (ds->ops->port_get_dscp_prio) {
                int protocol;

                for (protocol = 0; protocol < 64; protocol++) {
                        struct dcb_app app = {
                                .selector = IEEE_8021QAZ_APP_SEL_DSCP,
                                .protocol = protocol,
                        };
                        int prio;

                        prio = ds->ops->port_get_dscp_prio(ds, port, protocol);
                        if (prio == -EOPNOTSUPP)
                                continue;
                        if (prio < 0)
                                return prio;

                        app.priority = prio;

                        err = dcb_ieee_setapp(dev, &app);
                        if (err)
                                return err;
                }
        }

        return 0;
}

static const struct ethtool_ops dsa_user_ethtool_ops = {
        .get_drvinfo            = dsa_user_get_drvinfo,
        .get_regs_len           = dsa_user_get_regs_len,
        .get_regs               = dsa_user_get_regs,
        .nway_reset             = dsa_user_nway_reset,
        .get_link               = ethtool_op_get_link,
        .get_eeprom_len         = dsa_user_get_eeprom_len,
        .get_eeprom             = dsa_user_get_eeprom,
        .set_eeprom             = dsa_user_set_eeprom,
        .get_strings            = dsa_user_get_strings,
        .get_ethtool_stats      = dsa_user_get_ethtool_stats,
        .get_sset_count         = dsa_user_get_sset_count,
        .get_eth_phy_stats      = dsa_user_get_eth_phy_stats,
        .get_eth_mac_stats      = dsa_user_get_eth_mac_stats,
        .get_eth_ctrl_stats     = dsa_user_get_eth_ctrl_stats,
        .get_rmon_stats         = dsa_user_get_rmon_stats,
        .get_ts_stats           = dsa_user_get_ts_stats,
        .set_wol                = dsa_user_set_wol,
        .get_wol                = dsa_user_get_wol,
        .set_eee                = dsa_user_set_eee,
        .get_eee                = dsa_user_get_eee,
        .get_link_ksettings     = dsa_user_get_link_ksettings,
        .set_link_ksettings     = dsa_user_set_link_ksettings,
        .get_pause_stats        = dsa_user_get_pause_stats,
        .get_pauseparam         = dsa_user_get_pauseparam,
        .set_pauseparam         = dsa_user_set_pauseparam,
        .get_rxnfc              = dsa_user_get_rxnfc,
        .set_rxnfc              = dsa_user_set_rxnfc,
        .get_ts_info            = dsa_user_get_ts_info,
        .self_test              = dsa_user_net_selftest,
        .get_mm                 = dsa_user_get_mm,
        .set_mm                 = dsa_user_set_mm,
        .get_mm_stats           = dsa_user_get_mm_stats,
};

static const struct dcbnl_rtnl_ops __maybe_unused dsa_user_dcbnl_ops = {
        .ieee_setapp            = dsa_user_dcbnl_ieee_setapp,
        .ieee_delapp            = dsa_user_dcbnl_ieee_delapp,
        .dcbnl_setapptrust      = dsa_user_dcbnl_set_apptrust,
        .dcbnl_getapptrust      = dsa_user_dcbnl_get_apptrust,
};

static void dsa_user_get_stats64(struct net_device *dev,
                                 struct rtnl_link_stats64 *s)
{
        struct dsa_port *dp = dsa_user_to_port(dev);
        struct dsa_switch *ds = dp->ds;

        if (ds->ops->get_stats64)
                ds->ops->get_stats64(ds, dp->index, s);
        else
                dev_get_tstats64(dev, s);
}

static int dsa_user_fill_forward_path(struct net_device_path_ctx *ctx,
                                      struct net_device_path *path)
{
        struct dsa_port *dp = dsa_user_to_port(ctx->dev);
        struct net_device *conduit = dsa_port_to_conduit(dp);
        struct dsa_port *cpu_dp = dp->cpu_dp;

        path->dev = ctx->dev;
        path->type = DEV_PATH_DSA;
        path->dsa.proto = cpu_dp->tag_ops->proto;
        path->dsa.port = dp->index;
        ctx->dev = conduit;

        return 0;
}

static int dsa_user_hwtstamp_get(struct net_device *dev,
                                 struct kernel_hwtstamp_config *cfg)
{
        struct dsa_port *dp = dsa_user_to_port(dev);
        struct dsa_switch *ds = dp->ds;

        if (!ds->ops->port_hwtstamp_get)
                return -EOPNOTSUPP;

        return ds->ops->port_hwtstamp_get(ds, dp->index, cfg);
}

static int dsa_user_hwtstamp_set(struct net_device *dev,
                                 struct kernel_hwtstamp_config *cfg,
                                 struct netlink_ext_ack *extack)
{
        struct dsa_port *dp = dsa_user_to_port(dev);
        struct dsa_switch *ds = dp->ds;

        if (!ds->ops->port_hwtstamp_set)
                return -EOPNOTSUPP;

        return ds->ops->port_hwtstamp_set(ds, dp->index, cfg, extack);
}

static const struct net_device_ops dsa_user_netdev_ops = {
        .ndo_open               = dsa_user_open,
        .ndo_stop               = dsa_user_close,
        .ndo_start_xmit         = dsa_user_xmit,
        .ndo_change_rx_flags    = dsa_user_change_rx_flags,
        .ndo_set_rx_mode        = dsa_user_set_rx_mode,
        .ndo_set_mac_address    = dsa_user_set_mac_address,
        .ndo_fdb_dump           = dsa_user_fdb_dump,
        .ndo_eth_ioctl          = dsa_user_ioctl,
        .ndo_get_iflink         = dsa_user_get_iflink,
#ifdef CONFIG_NET_POLL_CONTROLLER
        .ndo_netpoll_setup      = dsa_user_netpoll_setup,
        .ndo_netpoll_cleanup    = dsa_user_netpoll_cleanup,
        .ndo_poll_controller    = dsa_user_poll_controller,
#endif
        .ndo_setup_tc           = dsa_user_setup_tc,
        .ndo_get_stats64        = dsa_user_get_stats64,
        .ndo_vlan_rx_add_vid    = dsa_user_vlan_rx_add_vid,
        .ndo_vlan_rx_kill_vid   = dsa_user_vlan_rx_kill_vid,
        .ndo_change_mtu         = dsa_user_change_mtu,
        .ndo_fill_forward_path  = dsa_user_fill_forward_path,
        .ndo_hwtstamp_get       = dsa_user_hwtstamp_get,
        .ndo_hwtstamp_set       = dsa_user_hwtstamp_set,
};

static const struct device_type dsa_type = {
        .name   = "dsa",
};

void dsa_port_phylink_mac_change(struct dsa_switch *ds, int port, bool up)
{
        const struct dsa_port *dp = dsa_to_port(ds, port);

        if (dp->pl)
                phylink_mac_change(dp->pl, up);
}
EXPORT_SYMBOL_GPL(dsa_port_phylink_mac_change);

static void dsa_user_phylink_fixed_state(struct phylink_config *config,
                                         struct phylink_link_state *state)
{
        struct dsa_port *dp = dsa_phylink_to_port(config);
        struct dsa_switch *ds = dp->ds;

        /* No need to check that this operation is valid, the callback would
         * not be called if it was not.
         */
        ds->ops->phylink_fixed_state(ds, dp->index, state);
}

/* user device setup *******************************************************/
static int dsa_user_phy_connect(struct net_device *user_dev, int addr,
                                u32 flags)
{
        struct dsa_port *dp = dsa_user_to_port(user_dev);
        struct dsa_switch *ds = dp->ds;

        user_dev->phydev = mdiobus_get_phy(ds->user_mii_bus, addr);
        if (!user_dev->phydev) {
                netdev_err(user_dev, "no phy at %d\n", addr);
                return -ENODEV;
        }

        user_dev->phydev->dev_flags |= flags;

        return phylink_connect_phy(dp->pl, user_dev->phydev);
}

static int dsa_user_phy_setup(struct net_device *user_dev)
{
        struct dsa_port *dp = dsa_user_to_port(user_dev);
        struct device_node *port_dn = dp->dn;
        struct dsa_switch *ds = dp->ds;
        u32 phy_flags = 0;
        int ret;

        dp->pl_config.dev = &user_dev->dev;
        dp->pl_config.type = PHYLINK_NETDEV;

        /* The get_fixed_state callback takes precedence over polling the
         * link GPIO in PHYLINK (see phylink_get_fixed_state).  Only set
         * this if the switch provides such a callback.
         */
        if (ds->ops->phylink_fixed_state) {
                dp->pl_config.get_fixed_state = dsa_user_phylink_fixed_state;
                dp->pl_config.poll_fixed_state = true;
        }

        ret = dsa_port_phylink_create(dp);
        if (ret)
                return ret;

        if (ds->ops->get_phy_flags)
                phy_flags = ds->ops->get_phy_flags(ds, dp->index);

        ret = phylink_of_phy_connect(dp->pl, port_dn, phy_flags);
        if (ret == -ENODEV && ds->user_mii_bus) {
                /* We could not connect to a designated PHY or SFP, so try to
                 * use the switch internal MDIO bus instead
                 */
                ret = dsa_user_phy_connect(user_dev, dp->index, phy_flags);
        }
        if (ret) {
                netdev_err(user_dev, "failed to connect to PHY: %pe\n",
                           ERR_PTR(ret));
                dsa_port_phylink_destroy(dp);
        }

        return ret;
}

void dsa_user_setup_tagger(struct net_device *user)
{
        struct dsa_port *dp = dsa_user_to_port(user);
        struct net_device *conduit = dsa_port_to_conduit(dp);
        struct dsa_user_priv *p = netdev_priv(user);
        const struct dsa_port *cpu_dp = dp->cpu_dp;
        const struct dsa_switch *ds = dp->ds;

        user->needed_headroom = cpu_dp->tag_ops->needed_headroom;
        user->needed_tailroom = cpu_dp->tag_ops->needed_tailroom;
        /* Try to save one extra realloc later in the TX path (in the conduit)
         * by also inheriting the conduit's needed headroom and tailroom.
         * The 8021q driver also does this.
         */
        user->needed_headroom += conduit->needed_headroom;
        user->needed_tailroom += conduit->needed_tailroom;

        p->xmit = cpu_dp->tag_ops->xmit;

        user->features = conduit->vlan_features | NETIF_F_HW_TC;
        user->hw_features |= NETIF_F_HW_TC;
        if (user->needed_tailroom)
                user->features &= ~(NETIF_F_SG | NETIF_F_FRAGLIST);
        if (ds->needs_standalone_vlan_filtering)
                user->features |= NETIF_F_HW_VLAN_CTAG_FILTER;

        user->lltx = true;
}

int dsa_user_suspend(struct net_device *user_dev)
{
        struct dsa_port *dp = dsa_user_to_port(user_dev);

        if (!netif_running(user_dev))
                return 0;

        netif_device_detach(user_dev);

        rtnl_lock();
        phylink_stop(dp->pl);
        rtnl_unlock();

        return 0;
}

int dsa_user_resume(struct net_device *user_dev)
{
        struct dsa_port *dp = dsa_user_to_port(user_dev);

        if (!netif_running(user_dev))
                return 0;

        netif_device_attach(user_dev);

        rtnl_lock();
        phylink_start(dp->pl);
        rtnl_unlock();

        return 0;
}

int dsa_user_create(struct dsa_port *port)
{
        struct net_device *conduit = dsa_port_to_conduit(port);
        struct dsa_switch *ds = port->ds;
        struct net_device *user_dev;
        struct dsa_user_priv *p;
        const char *name;
        int assign_type;
        int ret;

        if (!ds->num_tx_queues)
                ds->num_tx_queues = 1;

        if (port->name) {
                name = port->name;
                assign_type = NET_NAME_PREDICTABLE;
        } else {
                name = "eth%d";
                assign_type = NET_NAME_ENUM;
        }

        user_dev = alloc_netdev_mqs(sizeof(struct dsa_user_priv), name,
                                    assign_type, ether_setup,
                                    ds->num_tx_queues, 1);
        if (user_dev == NULL)
                return -ENOMEM;

        user_dev->rtnl_link_ops = &dsa_link_ops;
        user_dev->ethtool_ops = &dsa_user_ethtool_ops;
#if IS_ENABLED(CONFIG_DCB)
        user_dev->dcbnl_ops = &dsa_user_dcbnl_ops;
#endif
        if (!is_zero_ether_addr(port->mac))
                eth_hw_addr_set(user_dev, port->mac);
        else
                eth_hw_addr_inherit(user_dev, conduit);
        user_dev->priv_flags |= IFF_NO_QUEUE;
        if (dsa_switch_supports_uc_filtering(ds))
                user_dev->priv_flags |= IFF_UNICAST_FLT;
        user_dev->netdev_ops = &dsa_user_netdev_ops;
        if (ds->ops->port_max_mtu)
                user_dev->max_mtu = ds->ops->port_max_mtu(ds, port->index);
        SET_NETDEV_DEVTYPE(user_dev, &dsa_type);

        SET_NETDEV_DEV(user_dev, port->ds->dev);
        SET_NETDEV_DEVLINK_PORT(user_dev, &port->devlink_port);
        user_dev->dev.of_node = port->dn;
        user_dev->vlan_features = conduit->vlan_features;

        p = netdev_priv(user_dev);
        user_dev->pcpu_stat_type = NETDEV_PCPU_STAT_TSTATS;

        ret = gro_cells_init(&p->gcells, user_dev);
        if (ret)
                goto out_free;

        p->dp = port;
        INIT_LIST_HEAD(&p->mall_tc_list);
        port->user = user_dev;
        dsa_user_setup_tagger(user_dev);

        netif_carrier_off(user_dev);

        ret = dsa_user_phy_setup(user_dev);
        if (ret) {
                netdev_err(user_dev,
                           "error %d setting up PHY for tree %d, switch %d, port %d\n",
                           ret, ds->dst->index, ds->index, port->index);
                goto out_gcells;
        }

        rtnl_lock();

        ret = dsa_user_change_mtu(user_dev, ETH_DATA_LEN);
        if (ret && ret != -EOPNOTSUPP)
                dev_warn(ds->dev, "nonfatal error %d setting MTU to %d on port %d\n",
                         ret, ETH_DATA_LEN, port->index);

        ret = register_netdevice(user_dev);
        if (ret) {
                netdev_err(conduit, "error %d registering interface %s\n",
                           ret, user_dev->name);
                rtnl_unlock();
                goto out_phy;
        }

        if (IS_ENABLED(CONFIG_DCB)) {
                ret = dsa_user_dcbnl_init(user_dev);
                if (ret) {
                        netdev_err(user_dev,
                                   "failed to initialize DCB: %pe\n",
                                   ERR_PTR(ret));
                        rtnl_unlock();
                        goto out_unregister;
                }
        }

        ret = netdev_upper_dev_link(conduit, user_dev, NULL);

        rtnl_unlock();

        if (ret)
                goto out_unregister;

        return 0;

out_unregister:
        unregister_netdev(user_dev);
out_phy:
        rtnl_lock();
        phylink_disconnect_phy(p->dp->pl);
        rtnl_unlock();
        dsa_port_phylink_destroy(p->dp);
out_gcells:
        gro_cells_destroy(&p->gcells);
out_free:
        free_netdev(user_dev);
        port->user = NULL;
        return ret;
}

void dsa_user_destroy(struct net_device *user_dev)
{
        struct net_device *conduit = dsa_user_to_conduit(user_dev);
        struct dsa_port *dp = dsa_user_to_port(user_dev);
        struct dsa_user_priv *p = netdev_priv(user_dev);

        netif_carrier_off(user_dev);
        rtnl_lock();
        netdev_upper_dev_unlink(conduit, user_dev);
        unregister_netdevice(user_dev);
        phylink_disconnect_phy(dp->pl);
        rtnl_unlock();

        dsa_port_phylink_destroy(dp);
        gro_cells_destroy(&p->gcells);
        free_netdev(user_dev);
}

int dsa_user_change_conduit(struct net_device *dev, struct net_device *conduit,
                            struct netlink_ext_ack *extack)
{
        struct net_device *old_conduit = dsa_user_to_conduit(dev);
        struct dsa_port *dp = dsa_user_to_port(dev);
        struct dsa_switch *ds = dp->ds;
        struct net_device *upper;
        struct list_head *iter;
        int err;

        if (conduit == old_conduit)
                return 0;

        if (!ds->ops->port_change_conduit) {
                NL_SET_ERR_MSG_MOD(extack,
                                   "Driver does not support changing DSA conduit");
                return -EOPNOTSUPP;
        }

        if (!netdev_uses_dsa(conduit)) {
                NL_SET_ERR_MSG_MOD(extack,
                                   "Interface not eligible as DSA conduit");
                return -EOPNOTSUPP;
        }

        netdev_for_each_upper_dev_rcu(conduit, upper, iter) {
                if (dsa_user_dev_check(upper))
                        continue;
                if (netif_is_bridge_master(upper))
                        continue;
                NL_SET_ERR_MSG_MOD(extack, "Cannot join conduit with unknown uppers");
                return -EOPNOTSUPP;
        }

        /* Since we allow live-changing the DSA conduit, plus we auto-open the
         * DSA conduit when the user port opens => we need to ensure that the
         * new DSA conduit is open too.
         */
        if (dev->flags & IFF_UP) {
                err = dev_open(conduit, extack);
                if (err)
                        return err;
        }

        netdev_upper_dev_unlink(old_conduit, dev);

        err = netdev_upper_dev_link(conduit, dev, extack);
        if (err)
                goto out_revert_old_conduit_unlink;

        err = dsa_port_change_conduit(dp, conduit, extack);
        if (err)
                goto out_revert_conduit_link;

        /* Update the MTU of the new CPU port through cross-chip notifiers */
        err = dsa_user_change_mtu(dev, dev->mtu);
        if (err && err != -EOPNOTSUPP) {
                netdev_warn(dev,
                            "nonfatal error updating MTU with new conduit: %pe\n",
                            ERR_PTR(err));
        }

        return 0;

out_revert_conduit_link:
        netdev_upper_dev_unlink(conduit, dev);
out_revert_old_conduit_unlink:
        netdev_upper_dev_link(old_conduit, dev, NULL);
        return err;
}

bool dsa_user_dev_check(const struct net_device *dev)
{
        return dev->netdev_ops == &dsa_user_netdev_ops;
}
EXPORT_SYMBOL_GPL(dsa_user_dev_check);

static int dsa_user_changeupper(struct net_device *dev,
                                struct netdev_notifier_changeupper_info *info)
{
        struct netlink_ext_ack *extack;
        int err = NOTIFY_DONE;
        struct dsa_port *dp;

        if (!dsa_user_dev_check(dev))
                return err;

        dp = dsa_user_to_port(dev);
        extack = netdev_notifier_info_to_extack(&info->info);

        if (netif_is_bridge_master(info->upper_dev)) {
                if (info->linking) {
                        err = dsa_port_bridge_join(dp, info->upper_dev, extack);
                        if (!err)
                                dsa_bridge_mtu_normalization(dp);
                        if (err == -EOPNOTSUPP) {
                                NL_SET_ERR_MSG_WEAK_MOD(extack,
                                                        "Offloading not supported");
                                err = 0;
                        }
                        err = notifier_from_errno(err);
                } else {
                        dsa_port_bridge_leave(dp, info->upper_dev);
                        err = NOTIFY_OK;
                }
        } else if (netif_is_lag_master(info->upper_dev)) {
                if (info->linking) {
                        err = dsa_port_lag_join(dp, info->upper_dev,
                                                info->upper_info, extack);
                        if (err == -EOPNOTSUPP) {
                                NL_SET_ERR_MSG_WEAK_MOD(extack,
                                                        "Offloading not supported");
                                err = 0;
                        }
                        err = notifier_from_errno(err);
                } else {
                        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, extack);
                        if (err == -EOPNOTSUPP) {
                                NL_SET_ERR_MSG_WEAK_MOD(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;
}

static int dsa_user_prechangeupper(struct net_device *dev,
                                   struct netdev_notifier_changeupper_info *info)
{
        struct dsa_port *dp;

        if (!dsa_user_dev_check(dev))
                return NOTIFY_DONE;

        dp = dsa_user_to_port(dev);

        if (netif_is_bridge_master(info->upper_dev) && !info->linking)
                dsa_port_pre_bridge_leave(dp, info->upper_dev);
        else if (netif_is_lag_master(info->upper_dev) && !info->linking)
                dsa_port_pre_lag_leave(dp, info->upper_dev);
        /* dsa_port_pre_hsr_leave is not yet necessary since hsr devices cannot
         * meaningfully placed under a bridge yet
         */

        return NOTIFY_DONE;
}

static int
dsa_user_lag_changeupper(struct net_device *dev,
                         struct netdev_notifier_changeupper_info *info)
{
        struct net_device *lower;
        struct list_head *iter;
        int err = NOTIFY_DONE;
        struct dsa_port *dp;

        if (!netif_is_lag_master(dev))
                return err;

        netdev_for_each_lower_dev(dev, lower, iter) {
                if (!dsa_user_dev_check(lower))
                        continue;

                dp = dsa_user_to_port(lower);
                if (!dp->lag)
                        /* Software LAG */
                        continue;

                err = dsa_user_changeupper(lower, info);
                if (notifier_to_errno(err))
                        break;
        }

        return err;
}

/* Same as dsa_user_lag_changeupper() except that it calls
 * dsa_user_prechangeupper()
 */
static int
dsa_user_lag_prechangeupper(struct net_device *dev,
                            struct netdev_notifier_changeupper_info *info)
{
        struct net_device *lower;
        struct list_head *iter;
        int err = NOTIFY_DONE;
        struct dsa_port *dp;

        if (!netif_is_lag_master(dev))
                return err;

        netdev_for_each_lower_dev(dev, lower, iter) {
                if (!dsa_user_dev_check(lower))
                        continue;

                dp = dsa_user_to_port(lower);
                if (!dp->lag)
                        /* Software LAG */
                        continue;

                err = dsa_user_prechangeupper(lower, info);
                if (notifier_to_errno(err))
                        break;
        }

        return err;
}

static int
dsa_prevent_bridging_8021q_upper(struct net_device *dev,
                                 struct netdev_notifier_changeupper_info *info)
{
        struct netlink_ext_ack *ext_ack;
        struct net_device *user, *br;
        struct dsa_port *dp;

        ext_ack = netdev_notifier_info_to_extack(&info->info);

        if (!is_vlan_dev(dev))
                return NOTIFY_DONE;

        user = vlan_dev_real_dev(dev);
        if (!dsa_user_dev_check(user))
                return NOTIFY_DONE;

        dp = dsa_user_to_port(user);
        br = dsa_port_bridge_dev_get(dp);
        if (!br)
                return NOTIFY_DONE;

        /* Deny enslaving a VLAN device into a VLAN-aware bridge */
        if (br_vlan_enabled(br) &&
            netif_is_bridge_master(info->upper_dev) && info->linking) {
                NL_SET_ERR_MSG_MOD(ext_ack,
                                   "Cannot make VLAN device join VLAN-aware bridge");
                return notifier_from_errno(-EINVAL);
        }

        return NOTIFY_DONE;
}

static int
dsa_user_check_8021q_upper(struct net_device *dev,
                           struct netdev_notifier_changeupper_info *info)
{
        struct dsa_port *dp = dsa_user_to_port(dev);
        struct net_device *br = dsa_port_bridge_dev_get(dp);
        struct bridge_vlan_info br_info;
        struct netlink_ext_ack *extack;
        int err = NOTIFY_DONE;
        u16 vid;

        if (!br || !br_vlan_enabled(br))
                return NOTIFY_DONE;

        extack = netdev_notifier_info_to_extack(&info->info);
        vid = vlan_dev_vlan_id(info->upper_dev);

        /* br_vlan_get_info() returns -EINVAL or -ENOENT if the
         * device, respectively the VID is not found, returning
         * 0 means success, which is a failure for us here.
         */
        err = br_vlan_get_info(br, vid, &br_info);
        if (err == 0) {
                NL_SET_ERR_MSG_MOD(extack,
                                   "This VLAN is already configured by the bridge");
                return notifier_from_errno(-EBUSY);
        }

        return NOTIFY_DONE;
}

static int
dsa_user_prechangeupper_sanity_check(struct net_device *dev,
                                     struct netdev_notifier_changeupper_info *info)
{
        struct dsa_switch *ds;
        struct dsa_port *dp;
        int err;

        if (!dsa_user_dev_check(dev))
                return dsa_prevent_bridging_8021q_upper(dev, info);

        dp = dsa_user_to_port(dev);
        ds = dp->ds;

        if (ds->ops->port_prechangeupper) {
                err = ds->ops->port_prechangeupper(ds, dp->index, info);
                if (err)
                        return notifier_from_errno(err);
        }

        if (is_vlan_dev(info->upper_dev))
                return dsa_user_check_8021q_upper(dev, info);

        return NOTIFY_DONE;
}

/* To be eligible as a DSA conduit, a LAG must have all lower interfaces be
 * eligible DSA conduits. Additionally, all LAG slaves must be DSA conduits of
 * switches in the same switch tree.
 */
static int dsa_lag_conduit_validate(struct net_device *lag_dev,
                                    struct netlink_ext_ack *extack)
{
        struct net_device *lower1, *lower2;
        struct list_head *iter1, *iter2;

        netdev_for_each_lower_dev(lag_dev, lower1, iter1) {
                netdev_for_each_lower_dev(lag_dev, lower2, iter2) {
                        if (!netdev_uses_dsa(lower1) ||
                            !netdev_uses_dsa(lower2)) {
                                NL_SET_ERR_MSG_MOD(extack,
                                                   "All LAG ports must be eligible as DSA conduits");
                                return notifier_from_errno(-EINVAL);
                        }

                        if (lower1 == lower2)
                                continue;

                        if (!dsa_port_tree_same(lower1->dsa_ptr,
                                                lower2->dsa_ptr)) {
                                NL_SET_ERR_MSG_MOD(extack,
                                                   "LAG contains DSA conduits of disjoint switch trees");
                                return notifier_from_errno(-EINVAL);
                        }
                }
        }

        return NOTIFY_DONE;
}

static int
dsa_conduit_prechangeupper_sanity_check(struct net_device *conduit,
                                        struct netdev_notifier_changeupper_info *info)
{
        struct netlink_ext_ack *extack = netdev_notifier_info_to_extack(&info->info);

        if (!netdev_uses_dsa(conduit))
                return NOTIFY_DONE;

        if (!info->linking)
                return NOTIFY_DONE;

        /* Allow DSA switch uppers */
        if (dsa_user_dev_check(info->upper_dev))
                return NOTIFY_DONE;

        /* Allow bridge uppers of DSA conduits, subject to further
         * restrictions in dsa_bridge_prechangelower_sanity_check()
         */
        if (netif_is_bridge_master(info->upper_dev))
                return NOTIFY_DONE;

        /* Allow LAG uppers, subject to further restrictions in
         * dsa_lag_conduit_prechangelower_sanity_check()
         */
        if (netif_is_lag_master(info->upper_dev))
                return dsa_lag_conduit_validate(info->upper_dev, extack);

        NL_SET_ERR_MSG_MOD(extack,
                           "DSA conduit cannot join unknown upper interfaces");
        return notifier_from_errno(-EBUSY);
}

static int
dsa_lag_conduit_prechangelower_sanity_check(struct net_device *dev,
                                            struct netdev_notifier_changeupper_info *info)
{
        struct netlink_ext_ack *extack = netdev_notifier_info_to_extack(&info->info);
        struct net_device *lag_dev = info->upper_dev;
        struct net_device *lower;
        struct list_head *iter;

        if (!netdev_uses_dsa(lag_dev) || !netif_is_lag_master(lag_dev))
                return NOTIFY_DONE;

        if (!info->linking)
                return NOTIFY_DONE;

        if (!netdev_uses_dsa(dev)) {
                NL_SET_ERR_MSG(extack,
                               "Only DSA conduits can join a LAG DSA conduit");
                return notifier_from_errno(-EINVAL);
        }

        netdev_for_each_lower_dev(lag_dev, lower, iter) {
                if (!dsa_port_tree_same(dev->dsa_ptr, lower->dsa_ptr)) {
                        NL_SET_ERR_MSG(extack,
                                       "Interface is DSA conduit for a different switch tree than this LAG");
                        return notifier_from_errno(-EINVAL);
                }

                break;
        }

        return NOTIFY_DONE;
}

/* Don't allow bridging of DSA conduits, since the bridge layer rx_handler
 * prevents the DSA fake ethertype handler to be invoked, so we don't get the
 * chance to strip off and parse the DSA switch tag protocol header (the bridge
 * layer just returns RX_HANDLER_CONSUMED, stopping RX processing for these
 * frames).
 * The only case where that would not be an issue is when bridging can already
 * be offloaded, such as when the DSA conduit is itself a DSA or plain switchdev
 * port, and is bridged only with other ports from the same hardware device.
 */
static int
dsa_bridge_prechangelower_sanity_check(struct net_device *new_lower,
                                       struct netdev_notifier_changeupper_info *info)
{
        struct net_device *br = info->upper_dev;
        struct netlink_ext_ack *extack;
        struct net_device *lower;
        struct list_head *iter;

        if (!netif_is_bridge_master(br))
                return NOTIFY_DONE;

        if (!info->linking)
                return NOTIFY_DONE;

        extack = netdev_notifier_info_to_extack(&info->info);

        netdev_for_each_lower_dev(br, lower, iter) {
                if (!netdev_uses_dsa(new_lower) && !netdev_uses_dsa(lower))
                        continue;

                if (!netdev_port_same_parent_id(lower, new_lower)) {
                        NL_SET_ERR_MSG(extack,
                                       "Cannot do software bridging with a DSA conduit");
                        return notifier_from_errno(-EINVAL);
                }
        }

        return NOTIFY_DONE;
}

static void dsa_tree_migrate_ports_from_lag_conduit(struct dsa_switch_tree *dst,
                                                    struct net_device *lag_dev)
{
        struct net_device *new_conduit = dsa_tree_find_first_conduit(dst);
        struct dsa_port *dp;
        int err;

        dsa_tree_for_each_user_port(dp, dst) {
                if (dsa_port_to_conduit(dp) != lag_dev)
                        continue;

                err = dsa_user_change_conduit(dp->user, new_conduit, NULL);
                if (err) {
                        netdev_err(dp->user,
                                   "failed to restore conduit to %s: %pe\n",
                                   new_conduit->name, ERR_PTR(err));
                }
        }
}

static int dsa_conduit_lag_join(struct net_device *conduit,
                                struct net_device *lag_dev,
                                struct netdev_lag_upper_info *uinfo,
                                struct netlink_ext_ack *extack)
{
        struct dsa_port *cpu_dp = conduit->dsa_ptr;
        struct dsa_switch_tree *dst = cpu_dp->dst;
        struct dsa_port *dp;
        int err;

        err = dsa_conduit_lag_setup(lag_dev, cpu_dp, uinfo, extack);
        if (err)
                return err;

        dsa_tree_for_each_user_port(dp, dst) {
                if (dsa_port_to_conduit(dp) != conduit)
                        continue;

                err = dsa_user_change_conduit(dp->user, lag_dev, extack);
                if (err)
                        goto restore;
        }

        return 0;

restore:
        dsa_tree_for_each_user_port_continue_reverse(dp, dst) {
                if (dsa_port_to_conduit(dp) != lag_dev)
                        continue;

                err = dsa_user_change_conduit(dp->user, conduit, NULL);
                if (err) {
                        netdev_err(dp->user,
                                   "failed to restore conduit to %s: %pe\n",
                                   conduit->name, ERR_PTR(err));
                }
        }

        dsa_conduit_lag_teardown(lag_dev, conduit->dsa_ptr);

        return err;
}

static void dsa_conduit_lag_leave(struct net_device *conduit,
                                  struct net_device *lag_dev)
{
        struct dsa_port *dp, *cpu_dp = lag_dev->dsa_ptr;
        struct dsa_switch_tree *dst = cpu_dp->dst;
        struct dsa_port *new_cpu_dp = NULL;
        struct net_device *lower;
        struct list_head *iter;

        netdev_for_each_lower_dev(lag_dev, lower, iter) {
                if (netdev_uses_dsa(lower)) {
                        new_cpu_dp = lower->dsa_ptr;
                        break;
                }
        }

        if (new_cpu_dp) {
                /* Update the CPU port of the user ports still under the LAG
                 * so that dsa_port_to_conduit() continues to work properly
                 */
                dsa_tree_for_each_user_port(dp, dst)
                        if (dsa_port_to_conduit(dp) == lag_dev)
                                dp->cpu_dp = new_cpu_dp;

                /* Update the index of the virtual CPU port to match the lowest
                 * physical CPU port
                 */
                lag_dev->dsa_ptr = new_cpu_dp;
                wmb();
        } else {
                /* If the LAG DSA conduit has no ports left, migrate back all
                 * user ports to the first physical CPU port
                 */
                dsa_tree_migrate_ports_from_lag_conduit(dst, lag_dev);
        }

        /* This DSA conduit has left its LAG in any case, so let
         * the CPU port leave the hardware LAG as well
         */
        dsa_conduit_lag_teardown(lag_dev, conduit->dsa_ptr);
}

static int dsa_conduit_changeupper(struct net_device *dev,
                                   struct netdev_notifier_changeupper_info *info)
{
        struct netlink_ext_ack *extack;
        int err = NOTIFY_DONE;

        if (!netdev_uses_dsa(dev))
                return err;

        extack = netdev_notifier_info_to_extack(&info->info);

        if (netif_is_lag_master(info->upper_dev)) {
                if (info->linking) {
                        err = dsa_conduit_lag_join(dev, info->upper_dev,
                                                   info->upper_info, extack);
                        err = notifier_from_errno(err);
                } else {
                        dsa_conduit_lag_leave(dev, info->upper_dev);
                        err = NOTIFY_OK;
                }
        }

        return err;
}

static int dsa_user_netdevice_event(struct notifier_block *nb,
                                    unsigned long event, void *ptr)
{
        struct net_device *dev = netdev_notifier_info_to_dev(ptr);

        switch (event) {
        case NETDEV_PRECHANGEUPPER: {
                struct netdev_notifier_changeupper_info *info = ptr;
                int err;

                err = dsa_user_prechangeupper_sanity_check(dev, info);
                if (notifier_to_errno(err))
                        return err;

                err = dsa_conduit_prechangeupper_sanity_check(dev, info);
                if (notifier_to_errno(err))
                        return err;

                err = dsa_lag_conduit_prechangelower_sanity_check(dev, info);
                if (notifier_to_errno(err))
                        return err;

                err = dsa_bridge_prechangelower_sanity_check(dev, info);
                if (notifier_to_errno(err))
                        return err;

                err = dsa_user_prechangeupper(dev, ptr);
                if (notifier_to_errno(err))
                        return err;

                err = dsa_user_lag_prechangeupper(dev, ptr);
                if (notifier_to_errno(err))
                        return err;

                break;
        }
        case NETDEV_CHANGEUPPER: {
                int err;

                err = dsa_user_changeupper(dev, ptr);
                if (notifier_to_errno(err))
                        return err;

                err = dsa_user_lag_changeupper(dev, ptr);
                if (notifier_to_errno(err))
                        return err;

                err = dsa_conduit_changeupper(dev, ptr);
                if (notifier_to_errno(err))
                        return err;

                break;
        }
        case NETDEV_CHANGELOWERSTATE: {
                struct netdev_notifier_changelowerstate_info *info = ptr;
                struct dsa_port *dp;
                int err = 0;

                if (dsa_user_dev_check(dev)) {
                        dp = dsa_user_to_port(dev);

                        err = dsa_port_lag_change(dp, info->lower_state_info);
                }

                /* Mirror LAG port events on DSA conduits that are in
                 * a LAG towards their respective switch CPU ports
                 */
                if (netdev_uses_dsa(dev)) {
                        dp = dev->dsa_ptr;

                        err = dsa_port_lag_change(dp, info->lower_state_info);
                }

                return notifier_from_errno(err);
        }
        case NETDEV_CHANGE:
        case NETDEV_UP: {
                /* Track state of conduit port.
                 * DSA driver may require the conduit port (and indirectly
                 * the tagger) to be available for some special operation.
                 */
                if (netdev_uses_dsa(dev)) {
                        struct dsa_port *cpu_dp = dev->dsa_ptr;
                        struct dsa_switch_tree *dst = cpu_dp->ds->dst;

                        /* Track when the conduit port is UP */
                        dsa_tree_conduit_oper_state_change(dst, dev,
                                                           netif_oper_up(dev));

                        /* Track when the conduit port is ready and can accept
                         * packet.
                         * NETDEV_UP event is not enough to flag a port as ready.
                         * We also have to wait for linkwatch_do_dev to dev_activate
                         * and emit a NETDEV_CHANGE event.
                         * We check if a conduit port is ready by checking if the dev
                         * have a qdisc assigned and is not noop.
                         */
                        dsa_tree_conduit_admin_state_change(dst, dev,
                                                            !qdisc_tx_is_noop(dev));

                        return NOTIFY_OK;
                }

                return NOTIFY_DONE;
        }
        case NETDEV_GOING_DOWN: {
                struct dsa_port *dp, *cpu_dp;
                struct dsa_switch_tree *dst;
                LIST_HEAD(close_list);

                if (!netdev_uses_dsa(dev))
                        return NOTIFY_DONE;

                cpu_dp = dev->dsa_ptr;
                dst = cpu_dp->ds->dst;

                dsa_tree_conduit_admin_state_change(dst, dev, false);

                list_for_each_entry(dp, &dst->ports, list) {
                        if (!dsa_port_is_user(dp))
                                continue;

                        if (dp->cpu_dp != cpu_dp)
                                continue;

                        list_add(&dp->user->close_list, &close_list);
                }

                netif_close_many(&close_list, true);

                return NOTIFY_OK;
        }
        default:
                break;
        }

        return NOTIFY_DONE;
}

static void
dsa_fdb_offload_notify(struct dsa_switchdev_event_work *switchdev_work)
{
        struct switchdev_notifier_fdb_info info = {};

        info.addr = switchdev_work->addr;
        info.vid = switchdev_work->vid;
        info.offloaded = true;
        call_switchdev_notifiers(SWITCHDEV_FDB_OFFLOADED,
                                 switchdev_work->orig_dev, &info.info, NULL);
}

static void dsa_user_switchdev_event_work(struct work_struct *work)
{
        struct dsa_switchdev_event_work *switchdev_work =
                container_of(work, struct dsa_switchdev_event_work, work);
        const unsigned char *addr = switchdev_work->addr;
        struct net_device *dev = switchdev_work->dev;
        u16 vid = switchdev_work->vid;
        struct dsa_switch *ds;
        struct dsa_port *dp;
        int err;

        dp = dsa_user_to_port(dev);
        ds = dp->ds;

        switch (switchdev_work->event) {
        case SWITCHDEV_FDB_ADD_TO_DEVICE:
                if (switchdev_work->host_addr)
                        err = dsa_port_bridge_host_fdb_add(dp, addr, vid);
                else if (dp->lag)
                        err = dsa_port_lag_fdb_add(dp, addr, vid);
                else
                        err = dsa_port_fdb_add(dp, addr, vid);
                if (err) {
                        dev_err(ds->dev,
                                "port %d failed to add %pM vid %d to fdb: %d\n",
                                dp->index, addr, vid, err);
                        break;
                }
                dsa_fdb_offload_notify(switchdev_work);
                break;

        case SWITCHDEV_FDB_DEL_TO_DEVICE:
                if (switchdev_work->host_addr)
                        err = dsa_port_bridge_host_fdb_del(dp, addr, vid);
                else if (dp->lag)
                        err = dsa_port_lag_fdb_del(dp, addr, vid);
                else
                        err = dsa_port_fdb_del(dp, addr, vid);
                if (err) {
                        dev_err(ds->dev,
                                "port %d failed to delete %pM vid %d from fdb: %d\n",
                                dp->index, addr, vid, err);
                }

                break;
        }

        kfree(switchdev_work);
}

static bool dsa_foreign_dev_check(const struct net_device *dev,
                                  const struct net_device *foreign_dev)
{
        const struct dsa_port *dp = dsa_user_to_port(dev);
        struct dsa_switch_tree *dst = dp->ds->dst;

        if (netif_is_bridge_master(foreign_dev))
                return !dsa_tree_offloads_bridge_dev(dst, foreign_dev);

        if (netif_is_bridge_port(foreign_dev))
                return !dsa_tree_offloads_bridge_port(dst, foreign_dev);

        /* Everything else is foreign */
        return true;
}

static int dsa_user_fdb_event(struct net_device *dev,
                              struct net_device *orig_dev,
                              unsigned long event, const void *ctx,
                              const struct switchdev_notifier_fdb_info *fdb_info)
{
        struct dsa_switchdev_event_work *switchdev_work;
        struct dsa_port *dp = dsa_user_to_port(dev);
        bool host_addr = fdb_info->is_local;
        struct dsa_switch *ds = dp->ds;

        if (ctx && ctx != dp)
                return 0;

        if (!dp->bridge)
                return 0;

        if (switchdev_fdb_is_dynamically_learned(fdb_info)) {
                if (dsa_port_offloads_bridge_port(dp, orig_dev))
                        return 0;

                /* FDB entries learned by the software bridge or by foreign
                 * bridge ports should be installed as host addresses only if
                 * the driver requests assisted learning.
                 */
                if (!ds->assisted_learning_on_cpu_port)
                        return 0;
        }

        /* Also treat FDB entries on foreign interfaces bridged with us as host
         * addresses.
         */
        if (dsa_foreign_dev_check(dev, orig_dev))
                host_addr = true;

        /* Check early that we're not doing work in vain.
         * Host addresses on LAG ports still require regular FDB ops,
         * since the CPU port isn't in a LAG.
         */
        if (dp->lag && !host_addr) {
                if (!ds->ops->lag_fdb_add || !ds->ops->lag_fdb_del)
                        return -EOPNOTSUPP;
        } else {
                if (!ds->ops->port_fdb_add || !ds->ops->port_fdb_del)
                        return -EOPNOTSUPP;
        }

        switchdev_work = kzalloc_obj(*switchdev_work, GFP_ATOMIC);
        if (!switchdev_work)
                return -ENOMEM;

        netdev_dbg(dev, "%s FDB entry towards %s, addr %pM vid %d%s\n",
                   event == SWITCHDEV_FDB_ADD_TO_DEVICE ? "Adding" : "Deleting",
                   orig_dev->name, fdb_info->addr, fdb_info->vid,
                   host_addr ? " as host address" : "");

        INIT_WORK(&switchdev_work->work, dsa_user_switchdev_event_work);
        switchdev_work->event = event;
        switchdev_work->dev = dev;
        switchdev_work->orig_dev = orig_dev;

        ether_addr_copy(switchdev_work->addr, fdb_info->addr);
        switchdev_work->vid = fdb_info->vid;
        switchdev_work->host_addr = host_addr;

        dsa_schedule_work(&switchdev_work->work);

        return 0;
}

/* Called under rcu_read_lock() */
static int dsa_user_switchdev_event(struct notifier_block *unused,
                                    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,
                                                     dsa_user_dev_check,
                                                     dsa_user_port_attr_set);
                return notifier_from_errno(err);
        case SWITCHDEV_FDB_ADD_TO_DEVICE:
        case SWITCHDEV_FDB_DEL_TO_DEVICE:
                err = switchdev_handle_fdb_event_to_device(dev, event, ptr,
                                                           dsa_user_dev_check,
                                                           dsa_foreign_dev_check,
                                                           dsa_user_fdb_event);
                return notifier_from_errno(err);
        default:
                return NOTIFY_DONE;
        }

        return NOTIFY_OK;
}

static int dsa_user_switchdev_blocking_event(struct notifier_block *unused,
                                             unsigned long event, void *ptr)
{
        struct net_device *dev = switchdev_notifier_info_to_dev(ptr);
        int err;

        switch (event) {
        case SWITCHDEV_PORT_OBJ_ADD:
                err = switchdev_handle_port_obj_add_foreign(dev, ptr,
                                                            dsa_user_dev_check,
                                                            dsa_foreign_dev_check,
                                                            dsa_user_port_obj_add);
                return notifier_from_errno(err);
        case SWITCHDEV_PORT_OBJ_DEL:
                err = switchdev_handle_port_obj_del_foreign(dev, ptr,
                                                            dsa_user_dev_check,
                                                            dsa_foreign_dev_check,
                                                            dsa_user_port_obj_del);
                return notifier_from_errno(err);
        case SWITCHDEV_PORT_ATTR_SET:
                err = switchdev_handle_port_attr_set(dev, ptr,
                                                     dsa_user_dev_check,
                                                     dsa_user_port_attr_set);
                return notifier_from_errno(err);
        }

        return NOTIFY_DONE;
}

static struct notifier_block dsa_user_nb __read_mostly = {
        .notifier_call  = dsa_user_netdevice_event,
};

struct notifier_block dsa_user_switchdev_notifier = {
        .notifier_call = dsa_user_switchdev_event,
};

struct notifier_block dsa_user_switchdev_blocking_notifier = {
        .notifier_call = dsa_user_switchdev_blocking_event,
};

int dsa_user_register_notifier(void)
{
        struct notifier_block *nb;
        int err;

        err = register_netdevice_notifier(&dsa_user_nb);
        if (err)
                return err;

        err = register_switchdev_notifier(&dsa_user_switchdev_notifier);
        if (err)
                goto err_switchdev_nb;

        nb = &dsa_user_switchdev_blocking_notifier;
        err = register_switchdev_blocking_notifier(nb);
        if (err)
                goto err_switchdev_blocking_nb;

        return 0;

err_switchdev_blocking_nb:
        unregister_switchdev_notifier(&dsa_user_switchdev_notifier);
err_switchdev_nb:
        unregister_netdevice_notifier(&dsa_user_nb);
        return err;
}

void dsa_user_unregister_notifier(void)
{
        struct notifier_block *nb;
        int err;

        nb = &dsa_user_switchdev_blocking_notifier;
        err = unregister_switchdev_blocking_notifier(nb);
        if (err)
                pr_err("DSA: failed to unregister switchdev blocking notifier (%d)\n", err);

        err = unregister_switchdev_notifier(&dsa_user_switchdev_notifier);
        if (err)
                pr_err("DSA: failed to unregister switchdev notifier (%d)\n", err);

        err = unregister_netdevice_notifier(&dsa_user_nb);
        if (err)
                pr_err("DSA: failed to unregister user notifier (%d)\n", err);
}