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(xa: &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(phydev: 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(phydev: 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(xa: &topo->phys, index: phy->phyindex, entry: pdn, GFP_KERNEL);
71 else
72 ret = xa_alloc_cyclic(xa: &topo->phys, id: &phy->phyindex, entry: pdn,
73 xa_limit_32b, next: &topo->next_phy_index,
74 GFP_KERNEL);
75
76 if (ret < 0)
77 goto err;
78
79 return 0;
80
81err:
82 kfree(objp: 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, index: 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(objp: pdn);
104}
105EXPORT_SYMBOL_GPL(phy_link_topo_del_phy);
106