// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Handling of a single switch port
 *
 * Copyright (c) 2017 Savoir-faire Linux Inc.
 *      Vivien Didelot <vivien.didelot@savoirfairelinux.com>
 */

#include <linux/if_bridge.h>
#include <linux/notifier.h>
#include <linux/of_mdio.h>
#include <linux/of_net.h>

#include "dsa_priv.h"

static int dsa_port_notify(const struct dsa_port *dp, unsigned long e, void *v)
{
        struct raw_notifier_head *nh = &dp->ds->dst->nh;
        int err;

        err = raw_notifier_call_chain(nh, e, v);

        return notifier_to_errno(err);
}

int dsa_port_set_state(struct dsa_port *dp, u8 state,
                       struct switchdev_trans *trans)
{
        struct dsa_switch *ds = dp->ds;
        int port = dp->index;

        if (switchdev_trans_ph_prepare(trans))
                return ds->ops->port_stp_state_set ? 0 : -EOPNOTSUPP;

        if (ds->ops->port_stp_state_set)
                ds->ops->port_stp_state_set(ds, port, state);

        if (ds->ops->port_fast_age) {
                /* Fast age FDB entries or flush appropriate forwarding database
                 * for the given port, if we are moving it from Learning or
                 * Forwarding state, to Disabled or Blocking or Listening state.
                 */

                if ((dp->stp_state == BR_STATE_LEARNING ||
                     dp->stp_state == BR_STATE_FORWARDING) &&
                    (state == BR_STATE_DISABLED ||
                     state == BR_STATE_BLOCKING ||
                     state == BR_STATE_LISTENING))
                        ds->ops->port_fast_age(ds, port);
        }

        dp->stp_state = state;

        return 0;
}

static void dsa_port_set_state_now(struct dsa_port *dp, u8 state)
{
        int err;

        err = dsa_port_set_state(dp, state, NULL);
        if (err)
                pr_err("DSA: failed to set STP state %u (%d)\n", state, err);
}

int dsa_port_enable(struct dsa_port *dp, struct phy_device *phy)
{
        struct dsa_switch *ds = dp->ds;
        int port = dp->index;
        int err;

        if (ds->ops->port_enable) {
                err = ds->ops->port_enable(ds, port, phy);
                if (err)
                        return err;
        }

        if (!dp->bridge_dev)
                dsa_port_set_state_now(dp, BR_STATE_FORWARDING);

        return 0;
}

void dsa_port_disable(struct dsa_port *dp)
{
        struct dsa_switch *ds = dp->ds;
        int port = dp->index;

        if (!dp->bridge_dev)
                dsa_port_set_state_now(dp, BR_STATE_DISABLED);

        if (ds->ops->port_disable)
                ds->ops->port_disable(ds, port);
}

int dsa_port_bridge_join(struct dsa_port *dp, struct net_device *br)
{
        struct dsa_notifier_bridge_info info = {
                .sw_index = dp->ds->index,
                .port = dp->index,
                .br = br,
        };
        int err;

        /* Set the flooding mode before joining the port in the switch */
        err = dsa_port_bridge_flags(dp, BR_FLOOD | BR_MCAST_FLOOD, NULL);
        if (err)
                return err;

        /* Here the interface is already bridged. Reflect the current
         * configuration so that drivers can program their chips accordingly.
         */
        dp->bridge_dev = br;

        err = dsa_port_notify(dp, DSA_NOTIFIER_BRIDGE_JOIN, &info);

        /* The bridging is rolled back on error */
        if (err) {
                dsa_port_bridge_flags(dp, 0, NULL);
                dp->bridge_dev = NULL;
        }

        return err;
}

void dsa_port_bridge_leave(struct dsa_port *dp, struct net_device *br)
{
        struct dsa_notifier_bridge_info info = {
                .sw_index = dp->ds->index,
                .port = dp->index,
                .br = br,
        };
        int err;

        /* Here the port is already unbridged. Reflect the current configuration
         * so that drivers can program their chips accordingly.
         */
        dp->bridge_dev = NULL;

        err = dsa_port_notify(dp, DSA_NOTIFIER_BRIDGE_LEAVE, &info);
        if (err)
                pr_err("DSA: failed to notify DSA_NOTIFIER_BRIDGE_LEAVE\n");

        /* Port is leaving the bridge, disable flooding */
        dsa_port_bridge_flags(dp, 0, NULL);

        /* Port left the bridge, put in BR_STATE_DISABLED by the bridge layer,
         * so allow it to be in BR_STATE_FORWARDING to be kept functional
         */
        dsa_port_set_state_now(dp, BR_STATE_FORWARDING);
}

static bool dsa_port_can_apply_vlan_filtering(struct dsa_port *dp,
                                              bool vlan_filtering)
{
        struct dsa_switch *ds = dp->ds;
        int i;

        if (!ds->vlan_filtering_is_global)
                return true;

        /* For cases where enabling/disabling VLAN awareness is global to the
         * switch, we need to handle the case where multiple bridges span
         * different ports of the same switch device and one of them has a
         * different setting than what is being requested.
         */
        for (i = 0; i < ds->num_ports; i++) {
                struct net_device *other_bridge;

                other_bridge = dsa_to_port(ds, i)->bridge_dev;
                if (!other_bridge)
                        continue;
                /* If it's the same bridge, it also has same
                 * vlan_filtering setting => no need to check
                 */
                if (other_bridge == dp->bridge_dev)
                        continue;
                if (br_vlan_enabled(other_bridge) != vlan_filtering) {
                        dev_err(ds->dev, "VLAN filtering is a global setting\n");
                        return false;
                }
        }
        return true;
}

int dsa_port_vlan_filtering(struct dsa_port *dp, bool vlan_filtering,
                            struct switchdev_trans *trans)
{
        struct dsa_switch *ds = dp->ds;
        int err;

        /* bridge skips -EOPNOTSUPP, so skip the prepare phase */
        if (switchdev_trans_ph_prepare(trans))
                return 0;

        if (!ds->ops->port_vlan_filtering)
                return 0;

        if (!dsa_port_can_apply_vlan_filtering(dp, vlan_filtering))
                return -EINVAL;

        if (dsa_port_is_vlan_filtering(dp) == vlan_filtering)
                return 0;

        err = ds->ops->port_vlan_filtering(ds, dp->index,
                                           vlan_filtering);
        if (err)
                return err;

        if (ds->vlan_filtering_is_global)
                ds->vlan_filtering = vlan_filtering;
        else
                dp->vlan_filtering = vlan_filtering;
        return 0;
}

int dsa_port_ageing_time(struct dsa_port *dp, clock_t ageing_clock,
                         struct switchdev_trans *trans)
{
        unsigned long ageing_jiffies = clock_t_to_jiffies(ageing_clock);
        unsigned int ageing_time = jiffies_to_msecs(ageing_jiffies);
        struct dsa_notifier_ageing_time_info info = {
                .ageing_time = ageing_time,
                .trans = trans,
        };

        if (switchdev_trans_ph_prepare(trans))
                return dsa_port_notify(dp, DSA_NOTIFIER_AGEING_TIME, &info);

        dp->ageing_time = ageing_time;

        return dsa_port_notify(dp, DSA_NOTIFIER_AGEING_TIME, &info);
}

int dsa_port_pre_bridge_flags(const struct dsa_port *dp, unsigned long flags,
                              struct switchdev_trans *trans)
{
        struct dsa_switch *ds = dp->ds;

        if (!ds->ops->port_egress_floods ||
            (flags & ~(BR_FLOOD | BR_MCAST_FLOOD)))
                return -EINVAL;

        return 0;
}

int dsa_port_bridge_flags(const struct dsa_port *dp, unsigned long flags,
                          struct switchdev_trans *trans)
{
        struct dsa_switch *ds = dp->ds;
        int port = dp->index;
        int err = 0;

        if (switchdev_trans_ph_prepare(trans))
                return 0;

        if (ds->ops->port_egress_floods)
                err = ds->ops->port_egress_floods(ds, port, flags & BR_FLOOD,
                                                  flags & BR_MCAST_FLOOD);

        return err;
}

int dsa_port_mrouter(struct dsa_port *dp, bool mrouter,
                     struct switchdev_trans *trans)
{
        struct dsa_switch *ds = dp->ds;
        int port = dp->index;

        if (switchdev_trans_ph_prepare(trans))
                return ds->ops->port_egress_floods ? 0 : -EOPNOTSUPP;

        return ds->ops->port_egress_floods(ds, port, true, mrouter);
}

int dsa_port_fdb_add(struct dsa_port *dp, const unsigned char *addr,
                     u16 vid)
{
        struct dsa_notifier_fdb_info info = {
                .sw_index = dp->ds->index,
                .port = dp->index,
                .addr = addr,
                .vid = vid,
        };

        return dsa_port_notify(dp, DSA_NOTIFIER_FDB_ADD, &info);
}

int dsa_port_fdb_del(struct dsa_port *dp, const unsigned char *addr,
                     u16 vid)
{
        struct dsa_notifier_fdb_info info = {
                .sw_index = dp->ds->index,
                .port = dp->index,
                .addr = addr,
                .vid = vid,

        };

        return dsa_port_notify(dp, DSA_NOTIFIER_FDB_DEL, &info);
}

int dsa_port_fdb_dump(struct dsa_port *dp, dsa_fdb_dump_cb_t *cb, void *data)
{
        struct dsa_switch *ds = dp->ds;
        int port = dp->index;

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

        return ds->ops->port_fdb_dump(ds, port, cb, data);
}

int dsa_port_mdb_add(const struct dsa_port *dp,
                     const struct switchdev_obj_port_mdb *mdb,
                     struct switchdev_trans *trans)
{
        struct dsa_notifier_mdb_info info = {
                .sw_index = dp->ds->index,
                .port = dp->index,
                .trans = trans,
                .mdb = mdb,
        };

        return dsa_port_notify(dp, DSA_NOTIFIER_MDB_ADD, &info);
}

int dsa_port_mdb_del(const struct dsa_port *dp,
                     const struct switchdev_obj_port_mdb *mdb)
{
        struct dsa_notifier_mdb_info info = {
                .sw_index = dp->ds->index,
                .port = dp->index,
                .mdb = mdb,
        };

        return dsa_port_notify(dp, DSA_NOTIFIER_MDB_DEL, &info);
}

int dsa_port_vlan_add(struct dsa_port *dp,
                      const struct switchdev_obj_port_vlan *vlan,
                      struct switchdev_trans *trans)
{
        struct dsa_notifier_vlan_info info = {
                .sw_index = dp->ds->index,
                .port = dp->index,
                .trans = trans,
                .vlan = vlan,
        };

        return dsa_port_notify(dp, DSA_NOTIFIER_VLAN_ADD, &info);
}

int dsa_port_vlan_del(struct dsa_port *dp,
                      const struct switchdev_obj_port_vlan *vlan)
{
        struct dsa_notifier_vlan_info info = {
                .sw_index = dp->ds->index,
                .port = dp->index,
                .vlan = vlan,
        };

        return dsa_port_notify(dp, DSA_NOTIFIER_VLAN_DEL, &info);
}

int dsa_port_vid_add(struct dsa_port *dp, u16 vid, u16 flags)
{
        struct switchdev_obj_port_vlan vlan = {
                .obj.id = SWITCHDEV_OBJ_ID_PORT_VLAN,
                .flags = flags,
                .vid_begin = vid,
                .vid_end = vid,
        };
        struct switchdev_trans trans;
        int err;

        trans.ph_prepare = true;
        err = dsa_port_vlan_add(dp, &vlan, &trans);
        if (err)
                return err;

        trans.ph_prepare = false;
        return dsa_port_vlan_add(dp, &vlan, &trans);
}
EXPORT_SYMBOL(dsa_port_vid_add);

int dsa_port_vid_del(struct dsa_port *dp, u16 vid)
{
        struct switchdev_obj_port_vlan vlan = {
                .obj.id = SWITCHDEV_OBJ_ID_PORT_VLAN,
                .vid_begin = vid,
                .vid_end = vid,
        };

        return dsa_port_vlan_del(dp, &vlan);
}
EXPORT_SYMBOL(dsa_port_vid_del);

static struct phy_device *dsa_port_get_phy_device(struct dsa_port *dp)
{
        struct device_node *phy_dn;
        struct phy_device *phydev;

        phy_dn = of_parse_phandle(dp->dn, "phy-handle", 0);
        if (!phy_dn)
                return NULL;

        phydev = of_phy_find_device(phy_dn);
        if (!phydev) {
                of_node_put(phy_dn);
                return ERR_PTR(-EPROBE_DEFER);
        }

        of_node_put(phy_dn);
        return phydev;
}

void dsa_port_phylink_validate(struct phylink_config *config,
                               unsigned long *supported,
                               struct phylink_link_state *state)
{
        struct dsa_port *dp = container_of(config, struct dsa_port, pl_config);
        struct dsa_switch *ds = dp->ds;

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

        ds->ops->phylink_validate(ds, dp->index, supported, state);
}
EXPORT_SYMBOL_GPL(dsa_port_phylink_validate);

int dsa_port_phylink_mac_link_state(struct phylink_config *config,
                                    struct phylink_link_state *state)
{
        struct dsa_port *dp = container_of(config, struct dsa_port, pl_config);
        struct dsa_switch *ds = dp->ds;

        /* Only called for SGMII and 802.3z */
        if (!ds->ops->phylink_mac_link_state)
                return -EOPNOTSUPP;

        return ds->ops->phylink_mac_link_state(ds, dp->index, state);
}
EXPORT_SYMBOL_GPL(dsa_port_phylink_mac_link_state);

void dsa_port_phylink_mac_config(struct phylink_config *config,
                                 unsigned int mode,
                                 const struct phylink_link_state *state)
{
        struct dsa_port *dp = container_of(config, struct dsa_port, pl_config);
        struct dsa_switch *ds = dp->ds;

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

        ds->ops->phylink_mac_config(ds, dp->index, mode, state);
}
EXPORT_SYMBOL_GPL(dsa_port_phylink_mac_config);

void dsa_port_phylink_mac_an_restart(struct phylink_config *config)
{
        struct dsa_port *dp = container_of(config, struct dsa_port, pl_config);
        struct dsa_switch *ds = dp->ds;

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

        ds->ops->phylink_mac_an_restart(ds, dp->index);
}
EXPORT_SYMBOL_GPL(dsa_port_phylink_mac_an_restart);

void dsa_port_phylink_mac_link_down(struct phylink_config *config,
                                    unsigned int mode,
                                    phy_interface_t interface)
{
        struct dsa_port *dp = container_of(config, struct dsa_port, pl_config);
        struct phy_device *phydev = NULL;
        struct dsa_switch *ds = dp->ds;

        if (dsa_is_user_port(ds, dp->index))
                phydev = dp->slave->phydev;

        if (!ds->ops->phylink_mac_link_down) {
                if (ds->ops->adjust_link && phydev)
                        ds->ops->adjust_link(ds, dp->index, phydev);
                return;
        }

        ds->ops->phylink_mac_link_down(ds, dp->index, mode, interface);
}
EXPORT_SYMBOL_GPL(dsa_port_phylink_mac_link_down);

void dsa_port_phylink_mac_link_up(struct phylink_config *config,
                                  unsigned int mode,
                                  phy_interface_t interface,
                                  struct phy_device *phydev)
{
        struct dsa_port *dp = container_of(config, struct dsa_port, pl_config);
        struct dsa_switch *ds = dp->ds;

        if (!ds->ops->phylink_mac_link_up) {
                if (ds->ops->adjust_link && phydev)
                        ds->ops->adjust_link(ds, dp->index, phydev);
                return;
        }

        ds->ops->phylink_mac_link_up(ds, dp->index, mode, interface, phydev);
}
EXPORT_SYMBOL_GPL(dsa_port_phylink_mac_link_up);

const struct phylink_mac_ops dsa_port_phylink_mac_ops = {
        .validate = dsa_port_phylink_validate,
        .mac_link_state = dsa_port_phylink_mac_link_state,
        .mac_config = dsa_port_phylink_mac_config,
        .mac_an_restart = dsa_port_phylink_mac_an_restart,
        .mac_link_down = dsa_port_phylink_mac_link_down,
        .mac_link_up = dsa_port_phylink_mac_link_up,
};

static int dsa_port_setup_phy_of(struct dsa_port *dp, bool enable)
{
        struct dsa_switch *ds = dp->ds;
        struct phy_device *phydev;
        int port = dp->index;
        int err = 0;

        phydev = dsa_port_get_phy_device(dp);
        if (!phydev)
                return 0;

        if (IS_ERR(phydev))
                return PTR_ERR(phydev);

        if (enable) {
                err = genphy_resume(phydev);
                if (err < 0)
                        goto err_put_dev;

                err = genphy_read_status(phydev);
                if (err < 0)
                        goto err_put_dev;
        } else {
                err = genphy_suspend(phydev);
                if (err < 0)
                        goto err_put_dev;
        }

        if (ds->ops->adjust_link)
                ds->ops->adjust_link(ds, port, phydev);

        dev_dbg(ds->dev, "enabled port's phy: %s", phydev_name(phydev));

err_put_dev:
        put_device(&phydev->mdio.dev);
        return err;
}

static int dsa_port_fixed_link_register_of(struct dsa_port *dp)
{
        struct device_node *dn = dp->dn;
        struct dsa_switch *ds = dp->ds;
        struct phy_device *phydev;
        int port = dp->index;
        int mode;
        int err;

        err = of_phy_register_fixed_link(dn);
        if (err) {
                dev_err(ds->dev,
                        "failed to register the fixed PHY of port %d\n",
                        port);
                return err;
        }

        phydev = of_phy_find_device(dn);

        mode = of_get_phy_mode(dn);
        if (mode < 0)
                mode = PHY_INTERFACE_MODE_NA;
        phydev->interface = mode;

        genphy_read_status(phydev);

        if (ds->ops->adjust_link)
                ds->ops->adjust_link(ds, port, phydev);

        put_device(&phydev->mdio.dev);

        return 0;
}

static int dsa_port_phylink_register(struct dsa_port *dp)
{
        struct dsa_switch *ds = dp->ds;
        struct device_node *port_dn = dp->dn;
        int mode, err;

        mode = of_get_phy_mode(port_dn);
        if (mode < 0)
                mode = PHY_INTERFACE_MODE_NA;

        dp->pl_config.dev = ds->dev;
        dp->pl_config.type = PHYLINK_DEV;

        dp->pl = phylink_create(&dp->pl_config, of_fwnode_handle(port_dn),
                                mode, &dsa_port_phylink_mac_ops);
        if (IS_ERR(dp->pl)) {
                pr_err("error creating PHYLINK: %ld\n", PTR_ERR(dp->pl));
                return PTR_ERR(dp->pl);
        }

        err = phylink_of_phy_connect(dp->pl, port_dn, 0);
        if (err && err != -ENODEV) {
                pr_err("could not attach to PHY: %d\n", err);
                goto err_phy_connect;
        }

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

        return 0;

err_phy_connect:
        phylink_destroy(dp->pl);
        return err;
}

int dsa_port_link_register_of(struct dsa_port *dp)
{
        struct dsa_switch *ds = dp->ds;

        if (!ds->ops->adjust_link)
                return dsa_port_phylink_register(dp);

        dev_warn(ds->dev,
                 "Using legacy PHYLIB callbacks. Please migrate to PHYLINK!\n");

        if (of_phy_is_fixed_link(dp->dn))
                return dsa_port_fixed_link_register_of(dp);
        else
                return dsa_port_setup_phy_of(dp, true);
}

void dsa_port_link_unregister_of(struct dsa_port *dp)
{
        struct dsa_switch *ds = dp->ds;

        if (!ds->ops->adjust_link) {
                rtnl_lock();
                phylink_disconnect_phy(dp->pl);
                rtnl_unlock();
                phylink_destroy(dp->pl);
                return;
        }

        if (of_phy_is_fixed_link(dp->dn))
                of_phy_deregister_fixed_link(dp->dn);
        else
                dsa_port_setup_phy_of(dp, false);
}

int dsa_port_get_phy_strings(struct dsa_port *dp, uint8_t *data)
{
        struct phy_device *phydev;
        int ret = -EOPNOTSUPP;

        if (of_phy_is_fixed_link(dp->dn))
                return ret;

        phydev = dsa_port_get_phy_device(dp);
        if (IS_ERR_OR_NULL(phydev))
                return ret;

        ret = phy_ethtool_get_strings(phydev, data);
        put_device(&phydev->mdio.dev);

        return ret;
}
EXPORT_SYMBOL_GPL(dsa_port_get_phy_strings);

int dsa_port_get_ethtool_phy_stats(struct dsa_port *dp, uint64_t *data)
{
        struct phy_device *phydev;
        int ret = -EOPNOTSUPP;

        if (of_phy_is_fixed_link(dp->dn))
                return ret;

        phydev = dsa_port_get_phy_device(dp);
        if (IS_ERR_OR_NULL(phydev))
                return ret;

        ret = phy_ethtool_get_stats(phydev, NULL, data);
        put_device(&phydev->mdio.dev);

        return ret;
}
EXPORT_SYMBOL_GPL(dsa_port_get_ethtool_phy_stats);

int dsa_port_get_phy_sset_count(struct dsa_port *dp)
{
        struct phy_device *phydev;
        int ret = -EOPNOTSUPP;

        if (of_phy_is_fixed_link(dp->dn))
                return ret;

        phydev = dsa_port_get_phy_device(dp);
        if (IS_ERR_OR_NULL(phydev))
                return ret;

        ret = phy_ethtool_get_sset_count(phydev);
        put_device(&phydev->mdio.dev);

        return ret;
}
EXPORT_SYMBOL_GPL(dsa_port_get_phy_sset_count);