path: root/net/dsa/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);

/**
 * 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).
 */
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</