Add a tracepoint to log when a cwnd reset occurs due to lack of
transmission on a call.
Add stat counters to count transmission underflows (ie. when we have tx
window space, but sendmsg doesn't manage to keep up), cwnd resets and
transmission failures.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
None of the spinlocks in rxrpc need a _bh annotation now as the RCU
callback routines no longer take spinlocks and the bulk of the packet
wrangling code is now run in the I/O thread, not softirq context.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Move the functions from the call->processor and local->processor work items
into the domain of the I/O thread.
The call event processor, now called from the I/O thread, then takes over
the job of cranking the call state machine, processing incoming packets and
transmitting DATA, ACK and ABORT packets. In a future patch,
rxrpc_send_ACK() will transmit the ACK on the spot rather than queuing it
for later transmission.
The call event processor becomes purely received-skb driven. It only
transmits things in response to events. We use "pokes" to queue a dummy
skb to make it do things like start/resume transmitting data. Timer expiry
also results in pokes.
The connection event processor, becomes similar, though crypto events, such
as dealing with CHALLENGE and RESPONSE packets is offloaded to a work item
to avoid doing crypto in the I/O thread.
The local event processor is removed and VERSION response packets are
generated directly from the packet parser. Similarly, ABORTs generated in
response to protocol errors will be transmitted immediately rather than
being pushed onto a queue for later transmission.
Changes:
========
ver #2)
- Fix a couple of introduced lock context imbalances.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Extract the peer address from an incoming packet earlier, at the beginning
of rxrpc_input_packet() and thence pass a pointer to it to various
functions that use it as part of the lookup rather than doing it on several
separate paths.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Shrink the region of rxrpc_input_packet() that is covered by the RCU read
lock so that it only covers the connection and call lookup. This means
that the bits now outside of that can call sleepable functions such as
kmalloc and sendmsg.
Also take a ref on the conn or call we're going to use before we drop the
RCU read lock.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
A received skbuff needs a ref when it gets put on a call data queue or conn
packet queue, and rxrpc_input_packet() and co. jump through a lot of hoops
to avoid double-dropping the skbuff ref so that we can avoid getting a ref
when we queue the packet.
Change this so that the skbuff ref is unconditionally dropped by the caller
of rxrpc_input_packet(). An additional ref is then taken on the packet if
it is pushed onto a queue.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Remove the RCU requirements from the peer's list of error targets so that
the error distributor can call sleeping functions.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Move DATA transmission into the call processor work item. In a future
patch, this will be called from the I/O thread rather than being itsown
work item.
This will allow DATA transmission to be driven directly by incoming ACKs,
pokes and timers as those are processed.
The Tx queue is also split: The queue of packets prepared by sendmsg is now
places in call->tx_sendmsg and the packet dispatcher decants the packets
into call->tx_buffer as space becomes available in the transmission
window. This allows sendmsg to run ahead of the available space to try and
prevent an underflow in transmission.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Copy client call parameters into rxrpc_call earlier so that that can be
used to convey them to the connection code - which can then be offloaded to
the I/O thread.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Provide a means by which an event notification can be sent to a call such
that the I/O thread can process it rather than it being done in a separate
workqueue. This will allow a lot of locking to be removed.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Don't use sk->sk_receive_queue.lock to guard socket state changes as the
socket mutex is sufficient.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Remove call->input_lock as it was only necessary to serialise access to the
state stored in the rxrpc_call struct by simultaneous softirq handlers
presenting received packets. They now dump the packets in a queue and a
single process-context handler now processes them.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Move the processing of error packets into the local endpoint I/O thread,
leaving the handover from UDP to merely transfer them into the local
endpoint queue.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Split the packet input handler to make the softirq side just dump the
received packet into the local endpoint receive queue and then call the
remainder of the input function from the I/O thread.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Create a per-local receive queue to which, in a future patch, all incoming
packets will be directed and an I/O thread that will process those packets
and perform all transmission of packets.
Destruction of the local endpoint is also moved from the local processor
work item (which will be absorbed) to the thread.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Split the code that handles packet reception in softirq mode as a prelude
to moving all the packet processing beyond routing to the appropriate call
and setting up of a new call out into process context.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Currently, rxrpc gives the connection's work item a ref on the connection
when it queues it - and this is called from the timer expiration function.
The problem comes when queue_work() fails (ie. the work item is already
queued): the timer routine must put the ref - but this may cause the
cleanup code to run.
This has the unfortunate effect that the cleanup code may then be run in
softirq context - which means that any spinlocks it might need to touch
have to be guarded to disable softirqs (ie. they need a "_bh" suffix).
(1) Don't give a ref to the work item.
(2) Simplify handling of service connections by adding a separate active
count so that the refcount isn't also used for this.
(3) Connection destruction for both client and service connections can
then be cleaned up by putting rxrpc_put_connection() out of line and
making a tidy progression through the destruction code (offloaded to a
workqueue if put from softirq or processor function context). The RCU
part of the cleanup then only deals with the freeing at the end.
(4) Make rxrpc_queue_conn() return immediately if it sees the active count
is -1 rather then queuing the connection.
(5) Make sure that the cleanup routine waits for the work item to
complete.
(6) Stash the rxrpc_net pointer in the conn struct so that the rcu free
routine can use it, even if the local endpoint has been freed.
Unfortunately, neither the timer nor the work item can simply get around
the problem by just using refcount_inc_not_zero() as the waits would still
have to be done, and there would still be the possibility of having to put
the ref in the expiration function.
Note the connection work item is mostly going to go away with the main
event work being transferred to the I/O thread, so the wait in (6) will
become obsolete.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Currently, rxrpc gives the call timer a ref on the call when it starts it
and this is passed along to the workqueue by the timer expiration function.
The problem comes when queue_work() fails (ie. the work item is already
queued): the timer routine must put the ref - but this may cause the
cleanup code to run.
This has the unfortunate effect that the cleanup code may then be run in
softirq context - which means that any spinlocks it might need to touch
have to be guarded to disable softirqs (ie. they need a "_bh" suffix).
Fix this by:
(1) Don't give a ref to the timer.
(2) Making the expiration function not do anything if the refcount is 0.
Note that this is more of an optimisation.
(3) Make sure that the cleanup routine waits for timer to complete.
However, this has a consequence that timer cannot give a ref to the work
item. Therefore the following fixes are also necessary:
(4) Don't give a ref to the work item.
(5) Make the work item return asap if it sees the ref count is 0.
(6) Make sure that the cleanup routine waits for the work item to
complete.
Unfortunately, neither the timer nor the work item can simply get around
the problem by just using refcount_inc_not_zero() as the waits would still
have to be done, and there would still be the possibility of having to put
the ref in the expiration function.
Note the call work item is going to go away with the work being transferred
to the I/O thread, so the wait in (6) will become obsolete.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
In rxrpc tracing, use enums to generate lists of points of interest rather
than __builtin_return_address() for the sk_buff tracepoint.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Add a tracepoint for the rxrpc_bundle refcounting.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
In rxrpc tracing, use enums to generate lists of points of interest rather
than __builtin_return_address() for the rxrpc_call tracepoint
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
In rxrpc tracing, use enums to generate lists of points of interest rather
than __builtin_return_address() for the rxrpc_conn tracepoint
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
In rxrpc tracing, use enums to generate lists of points of interest rather
than __builtin_return_address() for the rxrpc_peer tracepoint
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
In rxrpc tracing, use enums to generate lists of points of interest rather
than __builtin_return_address() for the rxrpc_local tracepoint
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Extract the code from a received rx ABORT packet much earlier and in a
single place and harmonise the responses to malformed ABORT packets.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Remove the rxrpc_conn_parameters struct from the rxrpc_connection and
rxrpc_bundle structs and emplace the members directly. These are going to
get filled in from the rxrpc_call struct in future.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Remove the _net() and knet() debugging macros in favour of tracepoints.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Remove the kproto() and _proto() debugging macros in preference to using
tracepoints for this.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
We should not now see duplicate packets in the recvmsg_queue. At one
point, jumbo packets that overlapped with already queued data would be
added to the queue and dealt with in recvmsg rather than in the softirq
input code, but now jumbo packets are split/cloned before being processed
by the input code and the subpackets can be discarded individually.
So remove the recvmsg-side code for handling this.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
rxrpc_kernel_call_is_complete() has been removed, so remove its declaration
too.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
When retransmitting a packet, rxrpc_resend() shouldn't be attaching a ref
to the call to the txbuf as that pins the call and prevents the call from
clearing the packet buffer.
Signed-off-by: David Howells <dhowells@redhat.com>
Fixes: d57a3a1516 ("rxrpc: Save last ACK's SACK table rather than marking txbufs")
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Implement an in-kernel rxperf server to allow kernel-based rxrpc services
to be tested directly, unlike with AFS where they're accessed by the
fileserver when the latter decides it wants to.
This is implemented as a module that, if loaded, opens UDP port 7009
(afs3-rmtsys) and listens on it for incoming calls. Calls can be generated
using the rxperf command shipped with OpenAFS, for example.
Changes
=======
ver #2)
- Use min_t() instead of min().
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
cc: Jakub Kicinski <kuba@kernel.org>
Fix the following checker warning:
../net/rxrpc/key.c:692:9: error: subtraction of different types can't work (different address spaces)
Checker is wrong in this case, but cast the pointers to unsigned long to
avoid the warning.
Whilst we're at it, reduce the assertions to WARN_ON() and return an error.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
The open code is defined as a helper function(tp_to_dev) on r8169_main.c,
which the open code is &tp->pci_dev->dev. The helper function was added
in commit 1e1205b7d3 ("r8169: add helper tp_to_dev"). And then later,
commit f1e911d5d0 ("r8169: add basic phylib support") added
r8169_phylink_handler function but it didn't use the helper function.
Thus, tp_to_dev() replaces the open code. This patch doesn't change logic.
Signed-off-by: Juhee Kang <claudiajkang@gmail.com>
Reviewed-by: Heiner Kallweit <hkallweit1@gmail.com>
Link: https://lore.kernel.org/r/20221129161244.5356-1-claudiajkang@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
As the nla_nest_start() may fail with NULL returned, the return value needs
to be checked.
Fixes: ce08cd344a ("wifi: nl80211: expose link information for interfaces")
Signed-off-by: Yuan Can <yuancan@huawei.com>
Link: https://lore.kernel.org/r/20221129014211.56558-1-yuancan@huawei.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
When building with -Wstringop-overflow, GCC's KASAN implementation does
not correctly perform bounds checking within some complex structures
when faced with literal offsets, and can get very confused. For example,
this warning is seen due to literal offsets into sturct ieee80211_hdr
that may or may not be large enough:
drivers/net/wireless/intel/iwlwifi/mvm/rxmq.c: In function 'iwl_mvm_rx_mpdu_mq':
drivers/net/wireless/intel/iwlwifi/mvm/rxmq.c:2022:29: warning: writing 1 byte into a region of size 0 [-Wstringop-overflow=]
2022 | *qc &= ~IEEE80211_QOS_CTL_A_MSDU_PRESENT;
In file included from drivers/net/wireless/intel/iwlwifi/mvm/fw-api.h:32,
from drivers/net/wireless/intel/iwlwifi/mvm/sta.h:15,
from drivers/net/wireless/intel/iwlwifi/mvm/mvm.h:27,
from drivers/net/wireless/intel/iwlwifi/mvm/rxmq.c:10:
drivers/net/wireless/intel/iwlwifi/mvm/../fw/api/rx.h:559:16: note: at offset [78, 166] into destination object 'mpdu_len' of size 2
559 | __le16 mpdu_len;
| ^~~~~~~~
Refactor ieee80211_get_qos_ctl() to avoid using literal offsets,
requiring the creation of the actual structure that is described in the
comments. Explicitly choose the desired offset, making the code more
human-readable too. This is one of the last remaining warning to fix
before enabling -Wstringop-overflow globally.
Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97490
Link: https://github.com/KSPP/linux/issues/181
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Kalle Valo <kvalo@kernel.org>
Cc: Gregory Greenman <gregory.greenman@intel.com>
Cc: "Gustavo A. R. Silva" <gustavoars@kernel.org>
Cc: linux-wireless@vger.kernel.org
Cc: netdev@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20221130212641.never.627-kees@kernel.org
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Vladimir Oltean says:
====================
Fix rtnl_mutex deadlock with DPAA2 and SFP modules
This patch set deliberately targets net-next and lacks Fixes: tags due
to caution on my part.
While testing some SFP modules on the Solidrun Honeycomb LX2K platform,
I noticed that rebooting causes a deadlock:
============================================
WARNING: possible recursive locking detected
6.1.0-rc5-07010-ga9b9500ffaac-dirty #656 Not tainted
--------------------------------------------
systemd-shutdow/1 is trying to acquire lock:
ffffa62db6cf42f0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock+0x1c/0x30
but task is already holding lock:
ffffa62db6cf42f0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock+0x1c/0x30
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(rtnl_mutex);
lock(rtnl_mutex);
*** DEADLOCK ***
May be due to missing lock nesting notation
6 locks held by systemd-shutdow/1:
#0: ffffa62db6863c70 (system_transition_mutex){+.+.}-{4:4}, at: __do_sys_reboot+0xd4/0x260
#1: ffff2f2b0176f100 (&dev->mutex){....}-{4:4}, at: device_shutdown+0xf4/0x260
#2: ffff2f2b017be900 (&dev->mutex){....}-{4:4}, at: device_shutdown+0x104/0x260
#3: ffff2f2b017680f0 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0x40/0x260
#4: ffff2f2b0e1608f0 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0x40/0x260
#5: ffffa62db6cf42f0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock+0x1c/0x30
stack backtrace:
CPU: 6 PID: 1 Comm: systemd-shutdow Not tainted 6.1.0-rc5-07010-ga9b9500ffaac-dirty #656
Hardware name: SolidRun LX2160A Honeycomb (DT)
Call trace:
lock_acquire+0x68/0x84
__mutex_lock+0x98/0x460
mutex_lock_nested+0x2c/0x40
rtnl_lock+0x1c/0x30
sfp_bus_del_upstream+0x1c/0xac
phylink_destroy+0x1c/0x50
dpaa2_mac_disconnect+0x28/0x70
dpaa2_eth_remove+0x1dc/0x1f0
fsl_mc_driver_remove+0x24/0x60
device_remove+0x70/0x80
device_release_driver_internal+0x1f0/0x260
device_links_unbind_consumers+0xe0/0x110
device_release_driver_internal+0x138/0x260
device_release_driver+0x18/0x24
bus_remove_device+0x12c/0x13c
device_del+0x16c/0x424
fsl_mc_device_remove+0x28/0x40
__fsl_mc_device_remove+0x10/0x20
device_for_each_child+0x5c/0xac
dprc_remove+0x94/0xb4
fsl_mc_driver_remove+0x24/0x60
device_remove+0x70/0x80
device_release_driver_internal+0x1f0/0x260
device_release_driver+0x18/0x24
bus_remove_device+0x12c/0x13c
device_del+0x16c/0x424
fsl_mc_bus_remove+0x8c/0x10c
fsl_mc_bus_shutdown+0x10/0x20
platform_shutdown+0x24/0x3c
device_shutdown+0x15c/0x260
kernel_restart+0x40/0xa4
__do_sys_reboot+0x1e4/0x260
__arm64_sys_reboot+0x24/0x30
But fixing this appears to be not so simple. The patch set represents my
attempt to address it.
In short, the problem is that dpaa2_mac_connect() and dpaa2_mac_disconnect()
call 2 phylink functions in a row, one takes rtnl_lock() itself -
phylink_create(), and one which requires rtnl_lock() to be held by the
caller - phylink_fwnode_phy_connect(). The existing approach in the
drivers is too simple. We take rtnl_lock() when calling dpaa2_mac_connect(),
which is what results in the deadlock.
Fixing just that creates another problem. The drivers make use of
rtnl_lock() for serializing with other code paths too. I think I've
found all those code paths, and established other mechanisms for
serializing with them.
====================
Link: https://lore.kernel.org/r/20221129141221.872653-1-vladimir.oltean@nxp.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
After the introduction of a private mac_lock that serializes access to
priv->mac (and port_priv->mac in the switch), the only remaining purpose
of rtnl_lock() is to satisfy the locking requirements of
phylink_fwnode_phy_connect() and phylink_disconnect_phy().
But the functions these live in, dpaa2_mac_connect() and
dpaa2_mac_disconnect(), have contradictory locking requirements.
While phylink_fwnode_phy_connect() wants rtnl_lock() to be held,
phylink_create() wants it to not be held.
Move the rtnl_lock() from top-level (in the dpaa2-eth and dpaa2-switch
drivers) to only surround the phylink calls that require it, in the
dpaa2-mac library code.
This is possible because dpaa2_mac_connect() and dpaa2_mac_disconnect()
run unlocked, and there isn't any danger of an AB/BA deadlock between
the rtnl_mutex and other private locks.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Tested-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
The dpaa2-switch driver uses a DPMAC in the same way as the dpaa2-eth
driver, so we need to duplicate the locking solution established by the
previous change to the switch driver as well.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Tested-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
The dpaa2 architecture permits dynamic connections between objects on
the fsl-mc bus, specifically between a DPNI object (represented by a
struct net_device) and a DPMAC object (represented by a struct phylink).
The DPNI driver is notified when those connections are created/broken
through the dpni_irq0_handler_thread() method. To ensure that ethtool
operations, as well as netdev up/down operations serialize with the
connection/disconnection of the DPNI with a DPMAC,
dpni_irq0_handler_thread() takes the rtnl_lock() to block those other
operations from taking place.
There is code called by dpaa2_mac_connect() which wants to acquire the
rtnl_mutex once again, see phylink_create() -> phylink_register_sfp() ->
sfp_bus_add_upstream() -> rtnl_lock(). So the strategy doesn't quite
work out, even though it's fairly simple.
Create a different strategy, where all code paths in the dpaa2-eth
driver access priv->mac only while they are holding priv->mac_lock.
The phylink instance is not created or connected to the PHY under the
priv->mac_lock, but only assigned to priv->mac then. This will eliminate
the reliance on the rtnl_mutex.
Add lockdep annotations and put comments where holding the lock is not
necessary, and priv->mac can be dereferenced freely.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Tested-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
dpaa2_eth_connect_mac() is called both from dpaa2_eth_probe() and from
dpni_irq0_handler_thread().
It could happen that the DPNI gets connected to a DPMAC on the fsl-mc
bus exactly during probe, as soon as the "endpoint change" interrupt is
requested in dpaa2_eth_setup_irqs(). This will cause the
dpni_irq0_handler_thread() to register a phylink instance for that DPMAC.
Then, the probing function will also try to register a phylink instance
for the same DPMAC, operation which should fail (and this will fail the
probing of the driver).
Reorder dpaa2_eth_setup_irqs() and dpaa2_eth_connect_mac(), such that
dpni_irq0_handler_thread() never races with the DPMAC-related portion of
the probing path.
Also reorder dpaa2_eth_disconnect_mac() to be in the mirror position of
dpaa2_eth_connect_mac() in the teardown path.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Tested-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
The helper function will gain a lockdep annotation in a future patch.
Make sure to benefit from it.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Tested-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
DPNIs and DPSW objects can connect and disconnect at runtime from DPMAC
objects on the same fsl-mc bus. The DPMAC object also holds "ethtool -S"
unstructured counters. Those counters are only shown for the entity
owning the netdev (DPNI, DPSW) if it's connected to a DPMAC.
The ethtool stringset code path is split into multiple callbacks, but
currently, connecting and disconnecting the DPMAC takes the rtnl_lock().
This blocks the entire ethtool code path from running, see
ethnl_default_doit() -> rtnl_lock() -> ops->prepare_data() ->
strset_prepare_data().
This is going to be a problem if we are going to no longer require
rtnl_lock() when connecting/disconnecting the DPMAC, because the DPMAC
could appear between ops->get_sset_count() and ops->get_strings().
If it appears out of the blue, we will provide a stringset into an array
that was dimensioned thinking the DPMAC wouldn't be there => array
accessed out of bounds.
There isn't really a good way to work around that, and I don't want to
put too much pressure on the ethtool framework by playing locking games.
Just make the DPMAC counters be always available. They'll be zeroes if
the DPNI or DPSW isn't connected to a DPMAC.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Tested-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
The dpaa2-switch has the exact same locking requirements when connected
to a DPMAC, so it needs port_priv->mac to always point either to NULL,
or to a DPMAC with a fully initialized phylink instance.
Make the same preparatory change in the dpaa2-switch driver as in the
dpaa2-eth one.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Tested-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
There are 2 requirements for correct code:
- Any time the driver accesses the priv->mac pointer at runtime, it
either holds NULL to indicate a DPNI-DPNI connection (or unconnected
DPNI), or a struct dpaa2_mac whose phylink instance was fully
initialized (created and connected to the PHY). No changes are made to
priv->mac while it is being used. Currently, rtnl_lock() watches over
the call to dpaa2_eth_connect_mac(), so it serves the purpose of
serializing this with all readers of priv->mac.
- dpaa2_mac_connect() should run unlocked, because inside it are 2
phylink calls with incompatible locking requirements: phylink_create()
requires that the rtnl_mutex isn't held, and phylink_fwnode_phy_connect()
requires that the rtnl_mutex is held. The only way to solve those
contradictory requirements is to let dpaa2_mac_connect() take
rtnl_lock() when it needs to.
To solve both requirements, we need to identify the writer side of the
priv->mac pointer, which can be wrapped in a mutex private to the driver
in a future patch. The dpaa2_mac_connect() cannot be part of the writer
side critical section, because of an AB/BA deadlock with rtnl_lock().
So the strategy needs to be that where we prepare the DPMAC by calling
dpaa2_mac_connect(), and only make priv->mac point to it once it's fully
prepared. This ensures that the writer side critical section has the
absolute minimum surface it can.
The reverse strategy is adopted in the dpaa2_eth_disconnect_mac() code
path. This makes sure that priv->mac is NULL when we start tearing down
the DPMAC that we disconnected from, and concurrent code will simply not
see it.
No locking changes in this patch (concurrent code is still blocked by
the rtnl_mutex).
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Tested-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
dpaa2_mac_disconnect() will only be called with a NULL mac->phylink if
dpaa2_mac_connect() failed, or was never called.
The callers are these:
dpaa2_eth_disconnect_mac():
if (dpaa2_eth_is_type_phy(priv))
dpaa2_mac_disconnect(priv->mac);
dpaa2_switch_port_disconnect_mac():
if (dpaa2_switch_port_is_type_phy(port_priv))
dpaa2_mac_disconnect(port_priv->mac);
priv->mac can be NULL, but in that case, dpaa2_eth_is_type_phy() returns
false, and dpaa2_mac_disconnect() is never called. Similar for
dpaa2-switch.
When priv->mac is non-NULL, it means that dpaa2_mac_connect() returned
zero (success), and therefore, priv->mac->phylink is also a valid
pointer.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Tested-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
The phylink handling is intended to be hidden inside the dpaa2_mac
object. Move the phylink_start() call into dpaa2_mac_start(), and
phylink_stop() into dpaa2_mac_stop().
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Tested-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
dpaa2_mac_is_type_fixed() is a header with no implementation and no
callers, which is referenced from the documentation though. It can be
deleted.
On the other hand, it would be useful to reuse the code between
dpaa2_eth_is_type_phy() and dpaa2_switch_port_is_type_phy(). That common
code should be called dpaa2_mac_is_type_phy(), so let's create that.
The removal and the addition are merged into the same patch because,
in fact, is_type_phy() is the logical opposite of is_type_fixed().
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Tested-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
