MDIO bus controllers are not required to wait for write transactions to
complete before returning as synchronization is often achieved by polling
status bits.
This can cause issues when disabling interrupts since an interrupt could
fire before the interrupt handler is unregistered and there's no status
bit to poll.
Add a phy_write_barrier() function and use it in phy_disable_interrupts()
to fix this issue. The write barrier just reads an MII register and
discards the value, which is enough to guarantee that previous writes have
completed.
Signed-off-by: Charles Perry <charles.perry@microchip.com>
Link: https://patch.msgid.link/20260408131821.1145334-4-charles.perry@microchip.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This was done entirely with mindless brute force, using
git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' |
xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/'
to convert the new alloc_obj() users that had a simple GFP_KERNEL
argument to just drop that argument.
Note that due to the extreme simplicity of the scripting, any slightly
more complex cases spread over multiple lines would not be triggered:
they definitely exist, but this covers the vast bulk of the cases, and
the resulting diff is also then easier to check automatically.
For the same reason the 'flex' versions will be done as a separate
conversion.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:
Single allocations: kmalloc(sizeof(TYPE), ...)
are replaced with: kmalloc_obj(TYPE, ...)
Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with: kmalloc_objs(TYPE, COUNT, ...)
Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...)
(where TYPE may also be *VAR)
The resulting allocations no longer return "void *", instead returning
"TYPE *".
Signed-off-by: Kees Cook <kees@kernel.org>
When a PHY is halted (e.g. `ip link set dev lan2 down`), several
fields in struct phy_device may still reflect the last active
connection. This leads to ethtool showing stale values even though
the link is down.
Reset selected fields in _phy_state_machine() when transitioning
to PHY_HALTED and the link was previously up:
- speed/duplex -> UNKNOWN, but only in autoneg mode (in forced mode
these fields carry configuration, not status)
- master_slave_state -> UNKNOWN if previously supported
- mdix -> INVALID (state only, same meaning as "unknown")
- lp_advertising -> always cleared
The cleanup is skipped if the PHY is in PHY_ERROR state, so the
last values remain available for diagnostics.
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://patch.msgid.link/20250917094751.2101285-1-o.rempel@pengutronix.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Clear EEE runtime flags when the PHY transitions to HALTED or ERROR
and the state machine drops the link. This avoids stale EEE state being
reported via ethtool after the PHY is stopped or hits an error.
This change intentionally only clears software runtime flags and avoids
MDIO accesses in HALTED/ERROR. A follow-up patch will address other
link state variables.
Suggested-by: Russell King (Oracle) <linux@armlinux.org.uk>
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Link: https://patch.msgid.link/20250912132000.1598234-1-o.rempel@pengutronix.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Problem description
===================
Lockdep reports a possible circular locking dependency (AB/BA) between
&pl->state_mutex and &phy->lock, as follows.
phylink_resolve() // acquires &pl->state_mutex
-> phylink_major_config()
-> phy_config_inband() // acquires &pl->phydev->lock
whereas all the other call sites where &pl->state_mutex and
&pl->phydev->lock have the locking scheme reversed. Everywhere else,
&pl->phydev->lock is acquired at the top level, and &pl->state_mutex at
the lower level. A clear example is phylink_bringup_phy().
The outlier is the newly introduced phy_config_inband() and the existing
lock order is the correct one. To understand why it cannot be the other
way around, it is sufficient to consider phylink_phy_change(), phylink's
callback from the PHY device's phy->phy_link_change() virtual method,
invoked by the PHY state machine.
phy_link_up() and phy_link_down(), the (indirect) callers of
phylink_phy_change(), are called with &phydev->lock acquired.
Then phylink_phy_change() acquires its own &pl->state_mutex, to
serialize changes made to its pl->phy_state and pl->link_config.
So all other instances of &pl->state_mutex and &phydev->lock must be
consistent with this order.
Problem impact
==============
I think the kernel runs a serious deadlock risk if an existing
phylink_resolve() thread, which results in a phy_config_inband() call,
is concurrent with a phy_link_up() or phy_link_down() call, which will
deadlock on &pl->state_mutex in phylink_phy_change(). Practically
speaking, the impact may be limited by the slow speed of the medium
auto-negotiation protocol, which makes it unlikely for the current state
to still be unresolved when a new one is detected, but I think the
problem is there. Nonetheless, the problem was discovered using lockdep.
Proposed solution
=================
Practically speaking, the phy_config_inband() requirement of having
phydev->lock acquired must transfer to the caller (phylink is the only
caller). There, it must bubble up until immediately before
&pl->state_mutex is acquired, for the cases where that takes place.
Solution details, considerations, notes
=======================================
This is the phy_config_inband() call graph:
sfp_upstream_ops :: connect_phy()
|
v
phylink_sfp_connect_phy()
|
v
phylink_sfp_config_phy()
|
| sfp_upstream_ops :: module_insert()
| |
| v
| phylink_sfp_module_insert()
| |
| | sfp_upstream_ops :: module_start()
| | |
| | v
| | phylink_sfp_module_start()
| | |
| v v
| phylink_sfp_config_optical()
phylink_start() | |
| phylink_resume() v v
| | phylink_sfp_set_config()
| | |
v v v
phylink_mac_initial_config()
| phylink_resolve()
| | phylink_ethtool_ksettings_set()
v v v
phylink_major_config()
|
v
phy_config_inband()
phylink_major_config() caller #1, phylink_mac_initial_config(), does not
acquire &pl->state_mutex nor do its callers. It must acquire
&pl->phydev->lock prior to calling phylink_major_config().
phylink_major_config() caller #2, phylink_resolve() acquires
&pl->state_mutex, thus also needs to acquire &pl->phydev->lock.
phylink_major_config() caller #3, phylink_ethtool_ksettings_set(), is
completely uninteresting, because it only calls phylink_major_config()
if pl->phydev is NULL (otherwise it calls phy_ethtool_ksettings_set()).
We need to change nothing there.
Other solutions
===============
The lock inversion between &pl->state_mutex and &pl->phydev->lock has
occurred at least once before, as seen in commit c718af2d00 ("net:
phylink: fix ethtool -A with attached PHYs"). The solution there was to
simply not call phy_set_asym_pause() under the &pl->state_mutex. That
cannot be extended to our case though, where the phy_config_inband()
call is much deeper inside the &pl->state_mutex section.
Fixes: 5fd0f1a02e ("net: phylink: add negotiation of in-band capabilities")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Link: https://patch.msgid.link/20250904125238.193990-2-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
phy_loopback() leaves it to the PHY driver to select the speed of the
loopback mode. Thus, the speed of the loopback mode depends on the PHY
driver in use.
Add support for speed selection to phy_loopback() to enable loopback
with defined speeds. Ensure that link up is signaled if speed changes
as speed is not allowed to change during link up. Link down and up is
necessary for a new speed.
Signed-off-by: Gerhard Engleder <gerhard@engleder-embedded.com>
Link: https://patch.msgid.link/20250312203010.47429-3-gerhard@engleder-embedded.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
As the link_caps array is efficient for <speed,duplex> lookups,
implement a function for speed/duplex lookups that matches a given
mask. This replicates to some extent the phy_lookup_settings()
behaviour, matching full link_capabilities instead of a single linkmode.
phy.c's phy_santize_settings() and phylink's
phylink_ethtool_ksettings_set() performs such lookup using the
phy_settings table, but are only interested in the actual speed/duplex
that were matched, rathet than the individual linkmode.
Similar to phy_lookup_settings(), the newly introduced phy_caps_lookup()
will run through the link_caps[] array by descending speed/duplex order.
If the link_capabilities for a given <speed/duplex> tuple intersects the
passed linkmodes, we consider that a match.
Similar to phy_lookup_settings(), we also allow passing an 'exact'
boolean, allowing non-exact match. Here, we MUST always match the
linkmodes mask, but we allow matching on lower speed settings.
Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Link: https://patch.msgid.link/20250307173611.129125-8-maxime.chevallier@bootlin.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Add an optional polling interface for PHY statistics to simplify driver
implementation.
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Introduce support for standardized PHY statistics reporting in ethtool
by extending the PHYLIB framework. Add the functions
phy_ethtool_get_phy_stats() and phy_ethtool_get_link_ext_stats() to
provide a consistent interface for retrieving PHY-level and
link-specific statistics. These functions are used within the ethtool
implementation to avoid direct access to the phy_device structure
outside of the PHYLIB framework.
A new structure, ethtool_phy_stats, is introduced to standardize PHY
statistics such as packet counts, byte counts, and error counters.
Drivers are updated to include callbacks for retrieving PHY and
link-specific statistics, ensuring values are explicitly set only for
supported fields, initialized with ETHTOOL_STAT_NOT_SET to avoid
ambiguity.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Update the phy_ethtool_get_eee() documentation to make it clear that
all members of struct ethtool_keee are written by this function.
keee.supported, keee.advertised, keee.lp_advertised and keee.eee_active
are all written by genphy_c45_ethtool_get_eee().
keee.tx_lpi_timer, keee.tx_lpi_enabled and keee.eee_enabled are all
written by eeecfg_to_eee().
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://patch.msgid.link/E1tJ9JH-006LIz-SO@rmk-PC.armlinux.org.uk
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Add a method to query the PHY's in-band capabilities for a PHY
interface mode.
Where the interface mode does not have in-band capability, or the PHY
driver has not been updated to return this information, then
phy_inband_caps() should return zero. Otherwise, PHY drivers will
return a value consisting of the following flags:
LINK_INBAND_DISABLE indicates that the hardware does not support
in-band signalling, or can have in-band signalling configured via
software to be disabled.
LINK_INBAND_ENABLE indicates that the hardware will use in-band
signalling, or can have in-band signalling configured via software
to be enabled.
LINK_INBAND_BYPASS indicates that the hardware has the ability to
bypass in-band signalling when enabled after a timeout if the link
partner does not respond to its in-band signalling.
This reports the PHY capabilities for the particular interface mode,
not the current configuration.
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Link: https://patch.msgid.link/E1tIUre-006ITz-KF@rmk-PC.armlinux.org.uk
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
