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Link topologies containing multiple network PHYs attached to the same net_device can be found when using a PHY as a media converter for use with an SFP connector, on which an SFP transceiver containing a PHY can be used. With the current model, the transceiver's PHY can't be used for operations such as cable testing, timestamping, macsec offload, etc. The reason being that most of the logic for these configuration, coming from either ethtool netlink or ioctls tend to use netdev->phydev, which in multi-phy systems will reference the PHY closest to the MAC. Introduce a numbering scheme allowing to enumerate PHY devices that belong to any netdev, which can in turn allow userspace to take more precise decisions with regard to each PHY's configuration. The numbering is maintained per-netdev, in a phy_device_list. The numbering works similarly to a netdevice's ifindex, with identifiers that are only recycled once INT_MAX has been reached. This prevents races that could occur between PHY listing and SFP transceiver removal/insertion. The identifiers are assigned at phy_attach time, as the numbering depends on the netdevice the phy is attached to. The PHY index can be re-used for PHYs that are persistent. Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
105 lines
2.4 KiB
C
105 lines
2.4 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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/*
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* Infrastructure to handle all PHY devices connected to a given netdev,
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* either directly or indirectly attached.
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*
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* Copyright (c) 2023 Maxime Chevallier<maxime.chevallier@bootlin.com>
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*/
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#include <linux/phy_link_topology.h>
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#include <linux/netdevice.h>
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#include <linux/phy.h>
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#include <linux/rtnetlink.h>
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#include <linux/xarray.h>
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struct phy_link_topology *phy_link_topo_create(struct net_device *dev)
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{
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struct phy_link_topology *topo;
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topo = kzalloc(sizeof(*topo), GFP_KERNEL);
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if (!topo)
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return ERR_PTR(-ENOMEM);
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xa_init_flags(&topo->phys, XA_FLAGS_ALLOC1);
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topo->next_phy_index = 1;
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return topo;
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}
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void phy_link_topo_destroy(struct phy_link_topology *topo)
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{
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if (!topo)
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return;
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xa_destroy(&topo->phys);
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kfree(topo);
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}
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int phy_link_topo_add_phy(struct phy_link_topology *topo,
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struct phy_device *phy,
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enum phy_upstream upt, void *upstream)
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{
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struct phy_device_node *pdn;
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int ret;
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pdn = kzalloc(sizeof(*pdn), GFP_KERNEL);
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if (!pdn)
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return -ENOMEM;
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pdn->phy = phy;
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switch (upt) {
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case PHY_UPSTREAM_MAC:
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pdn->upstream.netdev = (struct net_device *)upstream;
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if (phy_on_sfp(phy))
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pdn->parent_sfp_bus = pdn->upstream.netdev->sfp_bus;
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break;
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case PHY_UPSTREAM_PHY:
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pdn->upstream.phydev = (struct phy_device *)upstream;
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if (phy_on_sfp(phy))
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pdn->parent_sfp_bus = pdn->upstream.phydev->sfp_bus;
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break;
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default:
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ret = -EINVAL;
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goto err;
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}
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pdn->upstream_type = upt;
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/* Attempt to re-use a previously allocated phy_index */
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if (phy->phyindex) {
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ret = xa_insert(&topo->phys, phy->phyindex, pdn, GFP_KERNEL);
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/* Errors could be either -ENOMEM or -EBUSY. If the phy has an
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* index, and there's another entry at the same index, this is
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* unexpected and we still error-out
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*/
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if (ret)
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goto err;
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return 0;
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}
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ret = xa_alloc_cyclic(&topo->phys, &phy->phyindex, pdn, xa_limit_32b,
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&topo->next_phy_index, GFP_KERNEL);
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if (ret)
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goto err;
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return 0;
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err:
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kfree(pdn);
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return ret;
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}
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EXPORT_SYMBOL_GPL(phy_link_topo_add_phy);
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void phy_link_topo_del_phy(struct phy_link_topology *topo,
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struct phy_device *phy)
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{
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struct phy_device_node *pdn = xa_erase(&topo->phys, phy->phyindex);
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/* We delete the PHY from the topology, however we don't re-set the
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* phy->phyindex field. If the PHY isn't gone, we can re-assign it the
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* same index next time it's added back to the topology
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*/
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kfree(pdn);
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}
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EXPORT_SYMBOL_GPL(phy_link_topo_del_phy);
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