1// SPDX-License-Identifier: GPL-2.0+
  2/*
  3 * Infrastructure to handle all PHY devices connected to a given netdev,
  4 * either directly or indirectly attached.
  5 *
  6 * Copyright (c) 2023 Maxime Chevallier<maxime.chevallier@bootlin.com>
  7 */
  8
  9#include <linux/phy_link_topology.h>
 10#include <linux/phy.h>
 11#include <linux/rtnetlink.h>
 12#include <linux/xarray.h>
 13
 14static int netdev_alloc_phy_link_topology(struct net_device *dev)
 15{
 16	struct phy_link_topology *topo;
 17
 18	topo = kzalloc(sizeof(*topo), GFP_KERNEL);
 19	if (!topo)
 20		return -ENOMEM;
 21
 22	xa_init_flags(&topo->phys, XA_FLAGS_ALLOC1);
 23	topo->next_phy_index = 1;
 24
 25	dev->link_topo = topo;
 26
 27	return 0;
 28}
 29
 30int phy_link_topo_add_phy(struct net_device *dev,
 31			  struct phy_device *phy,
 32			  enum phy_upstream upt, void *upstream)
 33{
 34	struct phy_link_topology *topo = dev->link_topo;
 35	struct phy_device_node *pdn;
 36	int ret;
 37
 38	if (!topo) {
 39		ret = netdev_alloc_phy_link_topology(dev);
 40		if (ret)
 41			return ret;
 42
 43		topo = dev->link_topo;
 44	}
 45
 46	pdn = kzalloc(sizeof(*pdn), GFP_KERNEL);
 47	if (!pdn)
 48		return -ENOMEM;
 49
 50	pdn->phy = phy;
 51	switch (upt) {
 52	case PHY_UPSTREAM_MAC:
 53		pdn->upstream.netdev = (struct net_device *)upstream;
 54		if (phy_on_sfp(phy))
 55			pdn->parent_sfp_bus = pdn->upstream.netdev->sfp_bus;
 56		break;
 57	case PHY_UPSTREAM_PHY:
 58		pdn->upstream.phydev = (struct phy_device *)upstream;
 59		if (phy_on_sfp(phy))
 60			pdn->parent_sfp_bus = pdn->upstream.phydev->sfp_bus;
 61		break;
 62	default:
 63		ret = -EINVAL;
 64		goto err;
 65	}
 66	pdn->upstream_type = upt;
 67
 68	/* Attempt to re-use a previously allocated phy_index */
 69	if (phy->phyindex)
 70		ret = xa_insert(&topo->phys, phy->phyindex, pdn, GFP_KERNEL);
 71	else
 72		ret = xa_alloc_cyclic(&topo->phys, &phy->phyindex, pdn,
 73				      xa_limit_32b, &topo->next_phy_index,
 74				      GFP_KERNEL);
 75
 76	if (ret)
 77		goto err;
 78
 79	return 0;
 80
 81err:
 82	kfree(pdn);
 83	return ret;
 84}
 85EXPORT_SYMBOL_GPL(phy_link_topo_add_phy);
 86
 87void phy_link_topo_del_phy(struct net_device *dev,
 88			   struct phy_device *phy)
 89{
 90	struct phy_link_topology *topo = dev->link_topo;
 91	struct phy_device_node *pdn;
 92
 93	if (!topo)
 94		return;
 95
 96	pdn = xa_erase(&topo->phys, phy->phyindex);
 97
 98	/* We delete the PHY from the topology, however we don't re-set the
 99	 * phy->phyindex field. If the PHY isn't gone, we can re-assign it the
100	 * same index next time it's added back to the topology
101	 */
102
103	kfree(pdn);
104}
105EXPORT_SYMBOL_GPL(phy_link_topo_del_phy);