[PATCH net-next 02/13] net: phy: phy_link_topology: Add a helper for opportunistic alloc

Maxime Chevallier
2026-01-27T13:42:25Z

The phy_link_topology structure stores information about the PHY-related
components connected to a net_device. It is opportunistically allocated,
when we add the first item to the topology, as this is not relevant for
all kinds of net_devices.

In preparation for the addition of phy_port tracking in the topology,
let's make a dedicated helper for that allocation sequence.

Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
---
drivers/net/phy/phy_link_topology.c | 29 +++++++++++++++++++++--------
1 file changed, 21 insertions(+), 8 deletions(-)

diff --git a/drivers/net/phy/phy_link_topology.c b/drivers/net/phy/phy_link_topology.c
index 0e9e987f37dd..7dc2ff10c74a 100644
--- a/drivers/net/phy/phy_link_topology.c
+++ b/drivers/net/phy/phy_link_topology.c
@@ -27,21 +27,34 @@ static int netdev_alloc_phy_link_topology(struct net_device *dev)
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.
+ */
+ ret = netdev_alloc_phy_link_topology(dev);
+ if (ret)
+ return ERR_PTR(ret);
+
+ return dev->link_topo;
+}
+
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 = dev->link_topo;
+ struct phy_link_topology *topo;
struct phy_device_node *pdn;
int ret;

- if (!topo) {
- ret = netdev_alloc_phy_link_topology(dev);
- if (ret)
- return ret;
-
- topo = dev->link_topo;
- }
+ topo = phy_link_topo_get_or_alloc(dev);
+ if (IS_ERR(topo))
+ return PTR_ERR(topo);

pdn = kzalloc(sizeof(*pdn), GFP_KERNEL);
if (!pdn)
--
2.49.0