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// SPDX-License-Identifier: GPL-2.0+
/*
* Infrastructure to handle all PHY devices connected to a given netdev,
* either directly or indirectly attached.
*
* Copyright (c) 2023 Maxime Chevallier<maxime.chevallier@bootlin.com>
*/
#include <linux/phy_link_topology.h>
#include <linux/phy_port.h>
#include <linux/phy.h>
#include <linux/rtnetlink.h>
#include <linux/xarray.h>
#include <net/netdev_lock.h>
static int netdev_alloc_phy_link_topology(struct net_device *dev)
{
struct phy_link_topology *topo;
topo = kzalloc_obj(*topo);
if (!topo)
return -ENOMEM;
xa_init_flags(&topo->phys, XA_FLAGS_ALLOC1);
topo->next_phy_index = 1;
xa_init_flags(&topo->ports, XA_FLAGS_ALLOC1);
topo->next_port_index = 1;
dev->link_topo = topo;
return 0;
}
static struct phy_link_topology *phy_link_topo_get_or_alloc(struct net_device *dev)
{
int ret;
if (dev->link_topo)
return dev->link_topo;
/* The topology is allocated the first time we add an object to it.
* It is freed alongside the netdev. It can be called on multiple
* contexts:
* - It can be called from .probe() : No rtnl, no netdev_lock
* - .ndo_open() : rtnl and possibly netdev_lock
* - SFP state machine : rtnl held or not
*
* However, we can't really have races :
* - If we have a PHY, phy_link_topo_add_phy() will always run first
* and trigger the alloc. Only then the ports can be added through
* phylib or sfp.
* - If we don't, the SFP port for the cage is registered first, and
* only then other ports/PHYs can be registered.
*/
ret = netdev_alloc_phy_link_topology(dev);
if (ret)
return ERR_PTR(ret);
return dev->link_topo;
}
int phy_link_topo_add_port(struct net_device *dev, struct phy_port *port)
{
struct phy_link_topology *topo;
int ret;
/* Ports can now be queried without rtnl for ops-locked devices, which
* we don't support now as port retrieval is done under rtnl.
* We don't have phy_port enabled devices yet, let's make sure
* we are loudly warned about that when it happens.
*/
if (WARN_ON_ONCE(dev->netdev_ops && netdev_need_ops_lock(dev)))
return -EOPNOTSUPP;
topo = phy_link_topo_get_or_alloc(dev);
if (IS_ERR(topo))
return PTR_ERR(topo);
/* Attempt to re-use a previously allocated port_id */
if (port->id)
ret = xa_insert(&topo->ports, port->id, port, GFP_KERNEL);
else
ret = xa_alloc_cyclic(&topo->ports, &port->id, port,
xa_limit_32b, &topo->next_port_index,
GFP_KERNEL);
return ret < 0 ? ret : 0;
}
EXPORT_SYMBOL_GPL(phy_link_topo_add_port);
void phy_link_topo_del_port(struct net_device *dev, struct phy_port *port)
{
struct phy_link_topology *topo = dev->link_topo;
if (!topo)
return;
xa_erase(&topo->ports, port->id);
}
EXPORT_SYMBOL_GPL(phy_link_topo_del_port);
int phy_link_topo_add_phy(struct net_device *dev,
struct phy_device *phy,
enum phy_upstream upt, void *upstream)
{
struct phy_link_topology *topo;
struct phy_device_node *pdn;
struct phy_port *port;
int ret;
/* ethtool ops may run without rtnl_lock, and rtnl_lock is what
* currently protects the PHY topology. No driver currently mixes
* the two, flag if someone tries. See also:
* - ethnl_req_get_phydev()
* - phy_detach()
*/
if (WARN_ON_ONCE(netdev_need_ops_lock(dev)))
return -EOPNOTSUPP;
topo = phy_link_topo_get_or_alloc(dev);
if (IS_ERR(topo))
return PTR_ERR(topo);
pdn = kzalloc_obj(*pdn);
if (!pdn)
return -ENOMEM;
pdn->phy = phy;
switch (upt) {
case PHY_UPSTREAM_MAC:
pdn->upstream.netdev = (struct net_device *)upstream;
if (phy_on_sfp(phy))
pdn->parent_sfp_bus = pdn->upstream.netdev->sfp_bus;
break;
case PHY_UPSTREAM_PHY:
pdn->upstream.phydev = (struct phy_device *)upstream;
if (phy_on_sfp(phy))
pdn->parent_sfp_bus = pdn->upstream.phydev->sfp_bus;
break;
default:
ret = -EINVAL;
goto err;
}
pdn->upstream_type = upt;
/* Attempt to re-use a previously allocated phy_index */
if (phy->phyindex)
ret = xa_insert(&topo->phys, phy->phyindex, pdn, GFP_KERNEL);
else
ret = xa_alloc_cyclic(&topo->phys, &phy->phyindex, pdn,
xa_limit_32b, &topo->next_phy_index,
GFP_KERNEL);
if (ret < 0)
goto err;
/* Add all the PHY's ports to the topology */
list_for_each_entry(port, &phy->ports, head) {
ret = phy_link_topo_add_port(dev, port);
if (ret)
goto del_ports;
}
return 0;
del_ports:
list_for_each_entry_continue_reverse(port, &phy->ports, head)
phy_link_topo_del_port(dev, port);
xa_erase(&topo->phys, phy->phyindex);
err:
kfree(pdn);
return ret;
}
EXPORT_SYMBOL_GPL(phy_link_topo_add_phy);
void phy_link_topo_del_phy(struct net_device *dev,
struct phy_device *phy)
{
struct phy_link_topology *topo = dev->link_topo;
struct phy_device_node *pdn;
struct phy_port *port;
if (!topo)
return;
list_for_each_entry(port, &phy->ports, head)
phy_link_topo_del_port(dev, port);
pdn = xa_erase(&topo->phys, phy->phyindex);
/* We delete the PHY from the topology, however we don't re-set the
* phy->phyindex field. If the PHY isn't gone, we can re-assign it the
* same index next time it's added back to the topology
*/
kfree(pdn);
}
EXPORT_SYMBOL_GPL(phy_link_topo_del_phy);
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