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https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
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Jakub Kicinski
97f51bf91b
dev->hwprov tracks the active hwtstamp provider for the device.
Make it ops protected (instance lock if the netdev driver opts
into holding instance lock around callbacks, otherwise rtnl_lock).
hwprov is written and read in:
- drivers/net/phy/phy_device.c
phydev and ops protection don't currently mix, add a comment
- net/ethtool/
as of now holds both rtnl lock and ops lock, this one will
soon only hold one lock or the other
read in:
- net/core/dev_ioctl.c
holds both rtnl lock and ops lock
- net/core/timestamping.c
RCU reader
The new netdev_ops_lock_dereference() helper does not have
"compat" in the name. The name would be quite long and I think
in this case it should be obvious that we need _a_ lock.
netdev_lock_dereference() already exists and means dev->lock
is always expected.
Reviewed-by: Eric Dumazet <edumazet@google.com>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Link: https://patch.msgid.link/20260605002912.3456868-4-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
116 lines
2.6 KiB
C
116 lines
2.6 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/phy.h>
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#include <linux/rtnetlink.h>
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#include <linux/xarray.h>
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#include <net/netdev_lock.h>
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static int netdev_alloc_phy_link_topology(struct net_device *dev)
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{
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struct phy_link_topology *topo;
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topo = kzalloc_obj(*topo);
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if (!topo)
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return -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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dev->link_topo = topo;
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return 0;
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}
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int phy_link_topo_add_phy(struct net_device *dev,
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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_link_topology *topo = dev->link_topo;
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struct phy_device_node *pdn;
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int ret;
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/* ethtool ops may run without rtnl_lock, and rtnl_lock is what
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* currently protects the PHY topology. No driver currently mixes
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* the two, flag if someone tries. See also:
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* - ethnl_req_get_phydev()
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* - phy_detach()
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*/
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if (WARN_ON_ONCE(netdev_need_ops_lock(dev)))
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return -EOPNOTSUPP;
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if (!topo) {
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ret = netdev_alloc_phy_link_topology(dev);
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if (ret)
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return ret;
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topo = dev->link_topo;
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}
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pdn = kzalloc_obj(*pdn);
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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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else
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ret = xa_alloc_cyclic(&topo->phys, &phy->phyindex, pdn,
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xa_limit_32b, &topo->next_phy_index,
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GFP_KERNEL);
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if (ret < 0)
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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 net_device *dev,
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struct phy_device *phy)
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{
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struct phy_link_topology *topo = dev->link_topo;
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struct phy_device_node *pdn;
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if (!topo)
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return;
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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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