dsa2.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * net/dsa/dsa2.c - Hardware switch handling, binding version 2
 * Copyright (c) 2008-2009 Marvell Semiconductor
 * Copyright (c) 2013 Florian Fainelli <florian@openwrt.org>
 * Copyright (c) 2016 Andrew Lunn <andrew@lunn.ch>
 */

#include <linux/device.h>
#include <linux/err.h>
#include <linux/list.h>
#include <linux/netdevice.h>
#include <linux/slab.h>
#include <linux/rtnetlink.h>
#include <linux/of.h>
#include <linux/of_net.h>
#include <net/devlink.h>

#include "dsa_priv.h"

static DEFINE_MUTEX(dsa2_mutex);
LIST_HEAD(dsa_tree_list);

/* Track the bridges with forwarding offload enabled */
static unsigned long dsa_fwd_offloading_bridges;

/**
 * dsa_tree_notify - Execute code for all switches in a DSA switch tree.
 * @dst: collection of struct dsa_switch devices to notify.
 * @e: event, must be of type DSA_NOTIFIER_*
 * @v: event-specific value.
 *
 * Given a struct dsa_switch_tree, this can be used to run a function once for
 * each member DSA switch. The other alternative of traversing the tree is only
 * through its ports list, which does not uniquely list the switches.
 */
int dsa_tree_notify(struct dsa_switch_tree *dst, unsigned long e, void *v)
{
	struct raw_notifier_head *nh = &dst->nh;
	int err;

	err = raw_notifier_call_chain(nh, e, v);

	return notifier_to_errno(err);
}

/**
 * dsa_broadcast - Notify all DSA trees in the system.
 * @e: event, must be of type DSA_NOTIFIER_*
 * @v: event-specific value.
 *
 * Can be used to notify the switching fabric of events such as cross-chip
 * bridging between disjoint trees (such as islands of tagger-compatible
 * switches bridged by an incompatible middle switch).
 *
 * WARNING: this function is not reliable during probe time, because probing
 * between trees is asynchronous and not all DSA trees might have probed.
 */
int dsa_broadcast(unsigned long e, void *v)
{
	struct dsa_switch_tree *dst;
	int err = 0;

	list_for_each_entry(dst, &dsa_tree_list, list) {
		err = dsa_tree_notify(dst, e, v);
		if (err)
			break;
	}

	return err;
}

/**
 * dsa_lag_map() - Map LAG netdev to a linear LAG ID
 * @dst: Tree in which to record the mapping.
 * @lag: Netdev that is to be mapped to an ID.
 *
 * dsa_lag_id/dsa_lag_dev can then be used to translate between the
 * two spaces. The size of the mapping space is determined by the
 * driver by setting ds->num_lag_ids. It is perfectly legal to leave
 * it unset if it is not needed, in which case these functions become
 * no-ops.
 */
void dsa_lag_map(struct dsa_switch_tree *dst, struct net_device *lag)
{
	unsigned int id;

	if (dsa_lag_id(dst, lag) >= 0)
		/* Already mapped */
		return;

	for (id = 0; id < dst->lags_len; id++) {
		if (!dsa_lag_dev(dst, id)) {
			dst->lags[id] = lag;
			return;
		}
	}

	/* No IDs left, which is OK. Some drivers do not need it. The
	 * ones that do, e.g. mv88e6xxx, will discover that dsa_lag_id
	 * returns an error for this device when joining the LAG. The
	 * driver can then return -EOPNOTSUPP back to DSA, which will
	 * fall back to a software LAG.
	 */
}

/**
 * dsa_lag_unmap() - Remove a LAG ID mapping
 * @dst: Tree in which the mapping is recorded.
 * @lag: Netdev that was mapped.
 *
 * As there may be multiple users of the mapping, it is only removed
 * if there are no other references to it.
 */
void dsa_lag_unmap(struct dsa_switch_tree *dst, struct net_device *lag)
{
	struct dsa_port *dp;
	unsigned int id;

	dsa_lag_foreach_port(dp, dst, lag)
		/* There are remaining users of this mapping */
		return;

	dsa_lags_foreach_id(id, dst) {
		if (dsa_lag_dev(dst, id) == lag) {
			dst->lags[id] = NULL;
			break;
		}
	}
}

static int dsa_bridge_num_find(const struct net_device *bridge_dev)
{
	struct dsa_switch_tree *dst;
	struct dsa_port *dp;

	/* When preparing the offload for a port, it will have a valid
	 * dp->bridge_dev pointer but a not yet valid dp->bridge_num.
	 * However there might be other ports having the same dp->bridge_dev
	 * and a valid dp->bridge_num, so just ignore this port.
	 */
	list_for_each_entry(dst, &dsa_tree_list, list)
		list_for_each_entry(dp, &dst->ports, list)
			if (dp->bridge_dev == bridge_dev &&
			    dp->bridge_num != -1)
				return dp->bridge_num;

	return -1;
}

int dsa_bridge_num_get(const struct net_device *bridge_dev, int max)
{
	int bridge_num = dsa_bridge_num_find(bridge_dev);

	if (bridge_num < 0) {
		/* First port that offloads TX forwarding for this bridge */
		bridge_num = find_first_zero_bit(&dsa_fwd_offloading_bridges,
						 DSA_MAX_NUM_OFFLOADING_BRIDGES);
		if (bridge_num >= max)
			return -1;

		set_bit(bridge_num, &dsa_fwd_offloading_bridges);
	}

	return bridge_num;
}

void dsa_bridge_num_put(const struct net_device *bridge_dev, int bridge_num)
{
	/* Check if the bridge is still in use, otherwise it is time
	 * to clean it up so we can reuse this bridge_num later.
	 */
	if (dsa_bridge_num_find(bridge_dev) < 0)
		clear_bit(bridge_num, &dsa_fwd_offloading_bridges);
}

struct dsa_switch *dsa_switch_find(int tree_index, int sw_index)
{
	struct dsa_switch_tree *dst;
	struct dsa_port *dp;

	list_for_each_entry(dst, &dsa_tree_list, list) {
		if (dst->index != tree_index)
			continue;

		list_for_each_entry(dp, &dst->ports, list) {
			if (dp->ds->index != sw_index)
				continue;

			return dp->ds;
		}
	}

	return NULL;
}
EXPORT_SYMBOL_GPL(dsa_switch_find);

static struct dsa_switch_tree *dsa_tree_find(int index)
{
	struct dsa_switch_tree *dst;

	list_for_each_entry(dst, &dsa_tree_list, list)
		if (dst->index == index)
			return dst;

	return NULL;
}

static struct dsa_switch_tree *dsa_tree_alloc(int index)
{
	struct dsa_switch_tree *dst;

	dst = kzalloc(sizeof(*dst), GFP_KERNEL);
	if (!dst)
		return NULL;

	dst->index = index;

	INIT_LIST_HEAD(&dst->rtable);

	INIT_LIST_HEAD(&dst->ports);

	INIT_LIST_HEAD(&dst->list);
	list_add_tail(&dst->list, &dsa_tree_list);

	kref_init(&dst->refcount);

	return dst;
}

static void dsa_tree_free(struct dsa_switch_tree *dst)
{
	if (dst->tag_ops)
		dsa_tag_driver_put(dst->tag_ops);
	list_del(&dst->list);
	kfree(dst);
}

static struct dsa_switch_tree *dsa_tree_get(struct dsa_switch_tree *dst)
{
	if (dst)
		kref_get(&dst->refcount);

	return dst;
}

static struct dsa_switch_tree *dsa_tree_touch(int index)
{
	struct dsa_switch_tree *dst;

	dst = dsa_tree_find(index);
	if (dst)
		return dsa_tree_get(dst);
	else
		return dsa_tree_alloc(index);
}

static void dsa_tree_release(struct kref *ref)
{
	struct dsa_switch_tree *dst;

	dst = container_of(ref, struct dsa_switch_tree, refcount);

	dsa_tree_free(dst);
}

static void dsa_tree_put(struct dsa_switch_tree *dst)
{
	if (dst)
		kref_put(&dst->refcount, dsa_tree_release);
}

static struct dsa_port *dsa_tree_find_port_by_node(struct dsa_switch_tree *dst,
						   struct device_node *dn)
{
	struct dsa_port *dp;

	list_for_each_entry(dp, &dst->ports, list)
		if (dp->dn == dn)
			return dp;

	return NULL;
}

static struct dsa_link *dsa_link_touch(struct dsa_port *dp,
				       struct dsa_port *link_dp)
{
	struct dsa_switch *ds = dp->ds;
	struct dsa_switch_tree *dst;
	struct dsa_link *dl;

	dst = ds->dst;

	list_for_each_entry(dl, &dst->rtable, list)
		if (dl->dp == dp && dl->link_dp == link_dp)
			return dl;

	dl = kzalloc(sizeof(*dl), GFP_KERNEL);
	if (!dl)
		return NULL;

	dl->dp = dp;
	dl->link_dp = link_dp;

	INIT_LIST_HEAD(&dl->list);
	list_add_tail(&dl->list, &dst->rtable);

	return dl;
}

static bool dsa_port_setup_routing_table(struct dsa_port *dp)
{
	struct dsa_switch *ds = dp->ds;
	struct dsa_switch_tree *dst = ds->dst;
	struct device_node *dn = dp->dn;
	struct of_phandle_iterator it;
	struct dsa_port *link_dp;
	struct dsa_link *dl;
	int err;

	of_for_each_phandle(&it, err, dn, "link", NULL, 0) {
		link_dp = dsa_tree_find_port_by_node(dst, it.node);
		if (!link_dp) {
			of_node_put(it.node);
			return false;
		}

		dl = dsa_link_touch(dp, link_dp);
		if (!dl) {
			of_node_put(it.node);
			return false;
		}
	}

	return true;
}

static bool dsa_tree_setup_routing_table(struct dsa_switch_tree *dst)
{
	bool complete = true;
	struct dsa_port *dp;

	list_for_each_entry(dp, &dst->ports, list) {
		if (dsa_port_is_dsa(dp)) {
			complete = dsa_port_setup_routing_table(dp);
			if (!complete)
				break;
		}
	}

	return complete;
}

static struct dsa_port *dsa_tree_find_first_cpu(struct dsa_switch_tree *dst)
{
	struct dsa_port *dp;

	list_for_each_entry(dp, &dst->ports, list)
		if (dsa_port_is_cpu(dp))
			return dp;

	return NULL;
}

/* Assign the default CPU port (the first one in the tree) to all ports of the
 * fabric which don't already have one as part of their own switch.
 */
static int dsa_tree_setup_default_cpu(struct dsa_switch_tree *dst)
{
	struct dsa_port *cpu_dp, *dp;

	cpu_dp = dsa_tree_find_first_cpu(dst);
	if (!cpu_dp) {
		pr_err("DSA: tree %d has no CPU port\n", dst->index);
		return -EINVAL;
	}

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

		if (dsa_port_is_user(dp) || dsa_port_is_dsa(dp))
			dp->cpu_dp = cpu_dp;
	}

	return 0;
}

/* Perform initial assignment of CPU ports to user ports and DSA links in the
 * fabric, giving preference to CPU ports local to each switch. Default to
 * using the first CPU port in the switch tree if the port does not have a CPU
 * port local to this switch.
 */
static int dsa_tree_setup_cpu_ports(struct dsa_switch_tree *dst)
{
	struct dsa_port *cpu_dp, *dp;

	list_for_each_entry(cpu_dp, &dst->ports, list) {
		if (!dsa_port_is_cpu(cpu_dp))
			continue;

		/* Prefer a local CPU port */
		dsa_switch_for_each_port(dp, cpu_dp->ds) {
			/* Prefer the first local CPU port found */
			if (dp->cpu_dp)
				continue;

			if (dsa_port_is_user(dp) || dsa_port_is_dsa(dp))
				dp->cpu_dp = cpu_dp;
		}
	}

	return dsa_tree_setup_default_cpu(dst);
}

static void dsa_tree_teardown_cpu_ports(struct dsa_switch_tree *dst)
{
	struct dsa_port *dp;

	list_for_each_entry(dp, &dst->ports, list)
		if (dsa_port_is_user(dp) || dsa_port_is_dsa(dp))
			dp->cpu_dp = NULL;
}

static int dsa_port_setup(struct dsa_port *dp)
{
	struct devlink_port *dlp = &dp->devlink_port;
	bool dsa_port_link_registered = false;
	struct dsa_switch *ds = dp->ds;
	bool dsa_port_enabled = false;
	int err = 0;

	if (dp->setup)
		return 0;

	mutex_init(&dp->addr_lists_lock);
	INIT_LIST_HEAD(&dp->fdbs);
	INIT_LIST_HEAD(&dp->mdbs);

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

	switch (dp->type) {
	case DSA_PORT_TYPE_UNUSED:
		dsa_port_disable(dp);
		break;
	case DSA_PORT_TYPE_CPU:
		err = dsa_port_link_register_of(dp);
		if (err)
			break;
		dsa_port_link_registered = true;

		err = dsa_port_enable(dp, NULL);
		if (err)
			break;
		dsa_port_enabled = true;

		break;
	case DSA_PORT_TYPE_DSA:
		err = dsa_port_link_register_of(dp);
		if (err)
			break;
		dsa_port_link_registered = true;

		err = dsa_port_enable(dp, NULL);
		if (err)
			break;
		dsa_port_enabled = true;

		break;
	case DSA_PORT_TYPE_USER:
		of_get_mac_address(dp->dn, dp->mac);
		err = dsa_slave_create(dp);
		if (err)
			break;

		devlink_port_type_eth_set(dlp, dp->slave);
		break;
	}

	if (err && dsa_port_enabled)
		dsa_port_disable(dp);
	if (err && dsa_port_link_registered)
		dsa_port_link_unregister_of(dp);
	if (err) {
		if (ds->ops->port_teardown)
			ds->ops->port_teardown(ds, dp->index);
		return err;
	}

	dp->setup = true;

	return 0;
}

static int dsa_port_devlink_setup(struct dsa_port *dp)
{
	struct devlink_port *dlp = &dp->devlink_port;
	struct dsa_switch_tree *dst = dp->ds->dst;
	struct devlink_port_attrs attrs = {};
	struct devlink *dl = dp->ds->devlink;
	const unsigned char *id;
	unsigned char len;
	int err;

	id = (const unsigned char *)&dst->index;
	len = sizeof(dst->index);

	attrs.phys.port_number = dp->index;
	memcpy(attrs.switch_id.id, id, len);
	attrs.switch_id.id_len = len;
	memset(dlp, 0, sizeof(*dlp));

	switch (dp->type) {
	case DSA_PORT_TYPE_UNUSED:
		attrs.flavour = DEVLINK_PORT_FLAVOUR_UNUSED;
		break;
	case DSA_PORT_TYPE_CPU:
		attrs.flavour = DEVLINK_PORT_FLAVOUR_CPU;
		break;
	case DSA_PORT_TYPE_DSA:
		attrs.flavour = DEVLINK_PORT_FLAVOUR_DSA;
		break;
	case DSA_PORT_TYPE_USER:
		attrs.flavour = DEVLINK_PORT_FLAVOUR_PHYSICAL;
		break;
	}

	devlink_port_attrs_set(dlp, &attrs);
	err = devlink_port_register(dl, dlp, dp->index);

	if (!err)
		dp->devlink_port_setup = true;

	return err;
}

static void dsa_port_teardown(struct dsa_port *dp)
{
	struct devlink_port *dlp = &dp->devlink_port;
	struct dsa_switch *ds = dp->ds;
	struct dsa_mac_addr *a, *tmp;

	if (!dp->setup)
		return;

	if (ds->ops->port_teardown)
		ds->ops->port_teardown(ds, dp->index);

	devlink_port_type_clear(dlp);

	switch (dp->type) {
	case DSA_PORT_TYPE_UNUSED:
		break;
	case DSA_PORT_TYPE_CPU:
		dsa_port_disable(dp);
		dsa_port_link_unregister_of(dp);
		break;
	case DSA_PORT_TYPE_DSA:
		dsa_port_disable(dp);
		dsa_port_link_unregister_of(dp);
		break;
	case DSA_PORT_TYPE_USER:
		if (dp->slave) {
			dsa_slave_destroy(dp->slave);
			dp->slave = NULL;
		}
		break;
	}

	list_for_each_entry_safe(a, tmp, &dp->fdbs, list) {
		list_del(&a->list);
		kfree(a);
	}

	list_for_each_entry_safe(a, tmp, &dp->mdbs, list) {
		list_del(&a->list);
		kfree(a);
	}

	dp->setup = false;
}

static void dsa_port_devlink_teardown(struct dsa_port *dp)
{
	struct devlink_port *dlp = &dp->devlink_port;

	if (dp->devlink_port_setup)
		devlink_port_unregister(dlp);
	dp->devlink_port_setup = false;
}

/* Destroy the current devlink port, and create a new one which has the UNUSED
 * flavour. At this point, any call to ds->ops->port_setup has been already
 * balanced out by a call to ds->ops->port_teardown, so we know that any
 * devlink port regions the driver had are now unregistered. We then call its
 * ds->ops->port_setup again, in order for the driver to re-create them on the
 * new devlink port.
 */
static int dsa_port_reinit_as_unused(struct dsa_port *dp)
{
	struct dsa_switch *ds = dp->ds;
	int err;

	dsa_port_devlink_teardown(dp);
	dp->type = DSA_PORT_TYPE_UNUSED;
	err = dsa_port_devlink_setup(dp);
	if (err)
		return err;

	if (ds->ops->port_setup) {
		/* On error, leave the devlink port registered,
		 * dsa_switch_teardown will clean it up later.
		 */
		err = ds->ops->port_setup(ds, dp->index);
		if (err)
			return err;
	}

	return 0;
}

static int dsa_devlink_info_get(struct devlink *dl,
				struct devlink_info_req *req,
				struct netlink_ext_ack *extack)
{
	struct dsa_switch *ds = dsa_devlink_to_ds(dl);

	if (ds->ops->devlink_info_get)
		return ds->ops->devlink_info_get(ds, req, extack);

	return -EOPNOTSUPP;
}

static int dsa_devlink_sb_pool_get(struct devlink *dl,
				   unsigned int sb_index, u16 pool_index,
				   struct devlink_sb_pool_info *pool_info)
{
	struct dsa_switch *ds = dsa_devlink_to_ds(dl);

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

	return ds->ops->devlink_sb_pool_get(ds, sb_index, pool_index,
					    pool_info);
}

static int dsa_devlink_sb_pool_set(struct devlink *dl, unsigned int sb_index,
				   u16 pool_index, u32 size,
				   enum devlink_sb_threshold_type threshold_type,
				   struct netlink_ext_ack *extack)
{
	struct dsa_switch *ds = dsa_devlink_to_ds(dl);

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

	return ds->ops->devlink_sb_pool_set(ds, sb_index, pool_index, size,
					    threshold_type, extack);
}

static int dsa_devlink_sb_port_pool_get(struct devlink_port *dlp,
					unsigned int sb_index, u16 pool_index,
					u32 *p_threshold)
{
	struct dsa_switch *ds = dsa_devlink_port_to_ds(dlp);
	int port = dsa_devlink_port_to_port(dlp);

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

	return ds->ops->devlink_sb_port_pool_get(ds, port, sb_index,
						 pool_index, p_threshold);
}

static int dsa_devlink_sb_port_pool_set(struct devlink_port *dlp,
					unsigned int sb_index, u16 pool_index,
					u32 threshold,
					struct netlink_ext_ack *extack)
{
	struct dsa_switch *ds = dsa_devlink_port_to_ds(dlp);
	int port = dsa_devlink_port_to_port(dlp);

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

	return ds->ops->devlink_sb_port_pool_set(ds, port, sb_index,
						 pool_index, threshold, extack);
}

static int
dsa_devlink_sb_tc_pool_bind_get(struct devlink_port *dlp,
				unsigned int sb_index, u16 tc_index,
				enum devlink_sb_pool_type pool_type,
				u16 *p_pool_index, u32 *p_threshold)
{
	struct dsa_switch *ds = dsa_devlink_port_to_ds(dlp);
	int port = dsa_devlink_port_to_port(dlp);

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

	return ds->ops->devlink_sb_tc_pool_bind_get(ds, port, sb_index,
						    tc_index, pool_type,
						    p_pool_index, p_threshold);
}

static int
dsa_devlink_sb_tc_pool_bind_set(struct devlink_port *dlp,
				unsigned int sb_index, u16 tc_index,
				enum devlink_sb_pool_type pool_type,
				u16 pool_index, u32 threshold,
				struct netlink_ext_ack *extack)
{
	struct dsa_switch *ds = dsa_devlink_port_to_ds(dlp);
	int port = dsa_devlink_port_to_port(dlp);

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

	return ds->ops->devlink_sb_tc_pool_bind_set(ds, port, sb_index,
						    tc_index, pool_type,
						    pool_index, threshold,
						    extack);
}

static int dsa_devlink_sb_occ_snapshot(struct devlink *dl,
				       unsigned int sb_index)
{
	struct dsa_switch *ds = dsa_devlink_to_ds(dl);

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

	return ds->ops->devlink_sb_occ_snapshot(ds, sb_index);
}

static int dsa_devlink_sb_occ_max_clear(struct devlink *dl,
					unsigned int sb_index)
{
	struct dsa_switch *ds = dsa_devlink_to_ds(dl);

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

	return ds->ops->devlink_sb_occ_max_clear(ds, sb_index);
}

static int dsa_devlink_sb_occ_port_pool_get(struct devlink_port *dlp,
					    unsigned int sb_index,
					    u16 pool_index, u32 *p_cur,
					    u32 *p_max)
{
	struct dsa_switch *ds = dsa_devlink_port_to_ds(dlp);
	int port = dsa_devlink_port_to_port(dlp);

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

	return ds->ops->devlink_sb_occ_port_pool_get(ds, port, sb_index,
						     pool_index, p_cur, p_max);
}

static int
dsa_devlink_sb_occ_tc_port_bind_get(struct devlink_port *dlp,
				    unsigned int sb_index, u16 tc_index,
				    enum devlink_sb_pool_type pool_type,
				    u32 *p_cur, u32 *p_max)
{
	struct dsa_switch *ds = dsa_devlink_port_to_ds(dlp);
	int port = dsa_devlink_port_to_port(dlp);

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

	return ds->ops->devlink_sb_occ_tc_port_bind_get(ds, port,
							sb_index, tc_index,
							pool_type, p_cur,
							p_max);
}

static const struct devlink_ops dsa_devlink_ops = {
	.info_get			= dsa_devlink_info_get,
	.sb_pool_get			= dsa_devlink_sb_pool_get,
	.sb_pool_set			= dsa_devlink_sb_pool_set,
	.sb_port_pool_get		= dsa_devlink_sb_port_pool_get,
	.sb_port_pool_set		= dsa_devlink_sb_port_pool_set,
	.sb_tc_pool_bind_get		= dsa_devlink_sb_tc_pool_bind_get,
	.sb_tc_pool_bind_set		= dsa_devlink_sb_tc_pool_bind_set,
	.sb_occ_snapshot		= dsa_devlink_sb_occ_snapshot,
	.sb_occ_max_clear		= dsa_devlink_sb_occ_max_clear,
	.sb_occ_port_pool_get		= dsa_devlink_sb_occ_port_pool_get,
	.sb_occ_tc_port_bind_get	= dsa_devlink_sb_occ_tc_port_bind_get,
};

static int dsa_switch_setup_tag_protocol(struct dsa_switch *ds)
{
	const struct dsa_device_ops *tag_ops = ds->dst->tag_ops;
	struct dsa_switch_tree *dst = ds->dst;
	struct dsa_port *cpu_dp;
	int err;

	if (tag_ops->proto == dst->default_proto)
		return 0;

	dsa_switch_for_each_cpu_port(cpu_dp, ds) {
		rtnl_lock();
		err = ds->ops->change_tag_protocol(ds, cpu_dp->index,
						   tag_ops->proto);
		rtnl_unlock();
		if (err) {
			dev_err(ds->dev, "Unable to use tag protocol \"%s\": %pe\n",
				tag_ops->name, ERR_PTR(err));
			return err;
		}
	}

	return 0;
}

static int dsa_switch_setup(struct dsa_switch *ds)
{
	struct dsa_devlink_priv *dl_priv;
	struct dsa_port *dp;
	int err;

	if (ds->setup)
		return 0;

	/* Initialize ds->phys_mii_mask before registering the slave MDIO bus
	 * driver and before ops->setup() has run, since the switch drivers and
	 * the slave MDIO bus driver rely on these values for probing PHY
	 * devices or not
	 */
	ds->phys_mii_mask |= dsa_user_ports(ds);

	/* Add the switch to devlink before calling setup, so that setup can
	 * add dpipe tables
	 */
	ds->devlink =
		devlink_alloc(&dsa_devlink_ops, sizeof(*dl_priv), ds->dev);
	if (!ds->devlink)
		return -ENOMEM;
	dl_priv = devlink_priv(ds->devlink);
	dl_priv->ds = ds;

	/* Setup devlink port instances now, so that the switch
	 * setup() can register regions etc, against the ports
	 */
	dsa_switch_for_each_port(dp, ds) {
		err = dsa_port_devlink_setup(dp);
		if (err)
			goto unregister_devlink_ports;
	}

	err = dsa_switch_register_notifier(ds);
	if (err)
		goto unregister_devlink_ports;

	ds->configure_vlan_while_not_filtering = true;

	err = ds->ops->setup(ds);
	if (err < 0)
		goto unregister_notifier;

	err = dsa_switch_setup_tag_protocol(ds);
	if (err)
		goto teardown;

	if (!ds->slave_mii_bus && ds->ops->phy_read) {
		ds->slave_mii_bus = mdiobus_alloc();
		if (!ds->slave_mii_bus) {
			err = -ENOMEM;
			goto teardown;
		}

		dsa_slave_mii_bus_init(ds);

		err = mdiobus_register(ds->slave_mii_bus);
		if (err < 0)
			goto free_slave_mii_bus;
	}

	ds->setup = true;
	devlink_register(ds->devlink);
	return 0;

free_slave_mii_bus:
	if (ds->slave_mii_bus && ds->ops->phy_read)
		mdiobus_free(ds->slave_mii_bus);
teardown:
	if (ds->ops->teardown)
		ds->ops->teardown(ds);
unregister_notifier:
	dsa_switch_unregister_notifier(ds);
unregister_devlink_ports:
	dsa_switch_for_each_port(dp, ds)
		dsa_port_devlink_teardown(dp);
	devlink_free(ds->devlink);
	ds->devlink = NULL;
	return err;
}

static void dsa_switch_teardown(struct dsa_switch *ds)
{
	struct dsa_port *dp;

	if (!ds->setup)
		return;

	if (ds->devlink)
		devlink_unregister(ds->devlink);

	if (ds->slave_mii_bus && ds->ops->phy_read) {
		mdiobus_unregister(ds->slave_mii_bus);
		mdiobus_free(ds->slave_mii_bus);
		ds->slave_mii_bus = NULL;
	}

	if (ds->ops->teardown)
		ds->ops->teardown(ds);

	dsa_switch_unregister_notifier(ds);

	if (ds->devlink) {
		dsa_switch_for_each_port(dp, ds)
			dsa_port_devlink_teardown(dp);
		devlink_free(ds->devlink);
		ds->devlink = NULL;
	}

	ds->setup = false;
}

/* First tear down the non-shared, then the shared ports. This ensures that
 * all work items scheduled by our switchdev handlers for user ports have
 * completed before we destroy the refcounting kept on the shared ports.
 */
static void dsa_tree_teardown_ports(struct dsa_switch_tree *dst)
{
	struct dsa_port *dp;

	list_for_each_entry(dp, &dst->ports, list)
		if (dsa_port_is_user(dp) || dsa_port_is_unused(dp))
			dsa_port_teardown(dp);

	dsa_flush_workqueue();

	list_for_each_entry(dp, &dst->ports, list)
		if (dsa_port_is_dsa(dp) || dsa_port_is_cpu(dp))
			dsa_port_teardown(dp);
}

static void dsa_tree_teardown_switches(struct dsa_switch_tree *dst)
{
	struct dsa_port *dp;

	list_for_each_entry(dp, &dst->ports, list)
		dsa_switch_teardown(dp->ds);
}

static int dsa_tree_setup_switches(struct dsa_switch_tree *dst)
{
	struct dsa_port *dp;
	int err;

	list_for_each_entry(dp, &dst->ports, list) {
		err = dsa_switch_setup(dp->ds);
		if (err)
			goto teardown;
	}

	list_for_each_entry(dp, &dst->ports, list) {
		err = dsa_port_setup(dp);
		if (err) {
			err = dsa_port_reinit_as_unused(dp);
			if (err)
				goto teardown;
		}
	}

	return 0;

teardown:
	dsa_tree_teardown_ports(dst);

	dsa_tree_teardown_switches(dst);

	return err;
}

static int dsa_tree_setup_master(struct dsa_switch_tree *dst)
{
	struct dsa_port *dp;
	int err;

	list_for_each_entry(dp, &dst->ports, list) {