When do_qdio() returns with an unexpected error, qeth_flush_buffers()
kicks off a recovery action.

In such a case there's no point in starting TX completion processing,
the device gets torn down anyway. So take a closer look at do_qdio()'s
return value, and skip the TX completion processing accordingly.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Acked-by: NWillem de Bruijn <willemb@google.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

Replace our home-grown helper with the more robust vlan_get_protocol().
This is pretty much a 1:1 replacement, we just need to pass around a
proper ETH_P_* everyhwere and convert the old value range.

For readability also convert the protocol checks in
qeth_l3_hard_start_xmit() to a switch statement.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Acked-by: NWillem de Bruijn <willemb@google.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

We have two usage patterns:
1. get & ->setup() a new discipline, or
2. ->remove() & put the currently loaded one.

Add corresponding helpers that hide the internals & error handling.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: NAlexandra Winter <wintera@linux.ibm.com>
Acked-by: NWillem de Bruijn <willemb@google.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

Due to insufficient locking, qeth_core_set_online() and
qeth_dev_layer2_store() can run in parallel, both attempting to load &
setup the discipline (and stepping on each other toes along the way).
A similar race can also occur between qeth_core_remove_device() and
qeth_dev_layer2_store().

Access to .discipline is meant to be protected by the discipline_mutex,
so add/expand the locking in qeth_core_remove_device() and
qeth_core_set_online().
Adjust the locking in qeth_l*_remove_device() accordingly, as it's now
handled by the callers in a consistent manner.

Based on an initial patch by Ursula Braun.

Fixes: 9dc48ccc ("qeth: serialize sysfs-triggered device configurations")
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: NAlexandra Winter <wintera@linux.ibm.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

When qeth_dev_layer2_store() - holding the discipline_mutex - waits
inside qeth_l*_remove_device() for a qeth_do_reset() thread to complete,
we can hit a deadlock if qeth_do_reset() concurrently calls
qeth_set_online() and thus tries to aquire the discipline_mutex.

Move the discipline_mutex locking outside of qeth_set_online() and
qeth_set_offline(), and turn the discipline into a parameter so that
callers understand the dependency.

To fix the deadlock, we can now relax the locking:
As already established, qeth_l*_remove_device() waits for
qeth_do_reset() to complete. So qeth_do_reset() itself is under no risk
of having card->discipline ripped out while it's running, and thus
doesn't need to take the discipline_mutex.

Fixes: 9dc48ccc ("qeth: serialize sysfs-triggered device configurations")
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: NAlexandra Winter <wintera@linux.ibm.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

When qeth_qdio_handle_aob() frees dangling allocations in the notified
TX buffer, there are rare tear-down cases where
qeth_drain_output_queue() would later call qeth_clear_output_buffer()
for the same buffer - and thus end up walking the buffer a second time
to check for dangling kmem_cache allocations.

Luckily current code previously scrubs such a buffer, so
qeth_clear_output_buffer() would find buf->buffer->element[i].addr as
NULL and not do anything. But this is fragile, and we can easily improve
it by consistently clearing the ->is_header flag after freeing the
allocation.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Reuse the QETH_QDIO_BUF_EMPTY state to indicate that a TX buffer has
been completed with a QAOB notification, and may be cleaned up by
qeth_cleanup_handled_pending().
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

For TX buffers that require an additional async notification via QAOB, the
TX completion code can now manage all the necessary processing if the
notification has already occurred (or is occurring concurrently).

In such cases we can avoid replacing the metadata that is associated
with the buffer's slot on the ring, and just keep using the current one.

As qeth_clear_output_buffer() will also handle any kmem cache-allocated
memory that was mapped into the TX buffer, qeth_qdio_handle_aob()
doesn't need to worry about it.

While at it, also remove the unneeded forward declaration for
qeth_init_qdio_out_buf().
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

All qeth devices have a minimum set of sysfs attributes, and non-OSN
devices share a group of additional attributes. Depending on whether
the device is forced to use a specific discipline, the device_type then
specifies further attributes.

Shift the common attributes into dev->groups, so that the device_type
only contains the discipline-specific attributes. This avoids exposing
the common attributes to the disciplines, and nicely cleans up our
sysfs code.

While replacing the qeth_l*_*_device_attributes() helpers, switch from
sysfs_*_groups() to the more generic device_*_groups().
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

INIT_LIST_HEAD() only needs to be called on actual list heads.
While at it clarify the naming of the field.
Suggested-by: NVasily Gorbik <gor@linux.ibm.com>
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When qeth_iqd_tx_complete() detects that a TX buffer requires additional
async completion via QAOB, it might fail to replace the queue entry's
metadata (and ends up triggering recovery).

Assume now that the device gets torn down, overruling the recovery.
If the QAOB notification then arrives before the tear down has
sufficiently progressed, the buffer state is changed to
QETH_QDIO_BUF_HANDLED_DELAYED by qeth_qdio_handle_aob().

The tear down code calls qeth_drain_output_queue(), where
qeth_cleanup_handled_pending() will then attempt to replace such a
buffer _again_. If it succeeds this time, the buffer ends up dangling in
its replacement's ->next_pending list ... where it will never be freed,
since there's no further call to qeth_cleanup_handled_pending().

But the second attempt isn't actually needed, we can simply leave the
buffer on the queue and re-use it after a potential recovery has
completed. The qeth_clear_output_buffer() in qeth_drain_output_queue()
will ensure that it's in a clean state again.

Fixes: 72861ae7 ("qeth: recovery through asynchronous delivery")
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

The two expected notification sequences are
1. TX_NOTIFY_PENDING with a subsequent TX_NOTIFY_DELAYED_*, when
   our TX completion code first observed the pending TX and the QAOB
   then completes at a later time; or
2. TX_NOTIFY_OK, when qeth_qdio_handle_aob() picked up the QAOB
   completion before our TX completion code even noticed that the TX
   was pending.

But as qeth_iqd_tx_complete() and qeth_qdio_handle_aob() can run
concurrently, we may end up with a race that results in a sequence of
TX_NOTIFY_DELAYED_* followed by TX_NOTIFY_PENDING. Which would confuse
the af_iucv code in its tracking of pending transmits.

Rework the notification code, so that qeth_qdio_handle_aob() defers its
notification if the TX completion code is still active.

Fixes: b3332930 ("qeth: add support for af_iucv HiperSockets transport")
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

Calling into socket code is ugly already, at least check whether we are
dealing with the expected sk_family. Only looking at skb->protocol is
bound to cause troubles (consider eg. af_packet).

Fixes: b3332930 ("qeth: add support for af_iucv HiperSockets transport")
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

The link mode is a combination of port speed and port mode. But we
currently only consider the speed, and then typically select the
corresponding TP-based link mode. For 1G and 10G Fibre links this means
we display the wrong link modes.

Move the SPEED_* switch statements inside the PORT_* cases, and only
consider valid combinations where we can select the corresponding
link mode. Add the relevant link modes (1000baseX, 10000baseSR and
1000baseLR) that were introduced back with
commit 5711a982 ("net: ethtool: add support for 1000BaseX and missing 10G link modes").

To differentiate between 10000baseSR and 10000baseLR, use the detailed
media_type information that QUERY OAT provides.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

Improve the initial link info with data obtained from QUERY OAT.
Doing so _only_ at initialization time avoids
1. dealing with multi-part replies, and
2. sifting through all the data that may get returned at runtime.

This allows us to determine the correct port type for the 1000BT variant
of recent OSA adapter generations (where the .card_type field in
QUERY CARD INFO is no longer sufficient).
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

Hard-code the minimal link info at initialization time, after we
obtained the link_type. qeth_get_link_ksettings() can still override
this with more accurate data from QUERY CARD INFO later on.

Don't set arbitrary defaults for unknown OSA link types, they
certainly won't match any future type.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

Move all the HW reply data parsing into qeth_query_card_info_cb(), and
use common ethtool enums for transporting the information back to the
caller.

Also only look at the .port_speed field when we couldn't determine the
speed from the .card_type field, and introduce some 'default' cases for
SPEED_UNKNOWN, PORT_OTHER and DUPLEX_UNKNOWN.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

- Add/delete some blanks, white spaces and braces.
- Fix misindentations.
- Adjust a deprecated header include, and htons() conversion.
- Remove extra 'return' statements.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Replace our custom version of netdev_name().

Once we started to allocate the netdev at probe time with
commit d3d1b205 ("s390/qeth: allocate netdevice early"), this
stopped working as intended anyway.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

For OSA devices that are _not_ configured in prio-queue mode, give users
the option of selecting the number of active TX queues.
This requires setting up the HW queues with a reasonable default QoS
value in the QIB's PQUE parm area.

As with the other device types, we bring up the device with a minimal
number of TX queues for compatibility reasons.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use a proper struct, and only program the QIB extensions for devices
where they are supported.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When re-initializing a device, we can hit a situation where
qeth_osa_set_output_queues() detects that it supports more or less
HW TX queues than before. Right now we adjust dev->real_num_tx_queues
from right there, but
1. it's getting more & more complicated to cover all cases, and
2. we can't re-enable the actually expected number of TX queues later
because we lost the needed information.

So keep track of the wanted TX queues (on initial setup, and whenever
its changed via .set_channels), and later use that information when
re-enabling the netdevice.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Clarify which discipline-specific steps are needed to roll back after
error in qeth_l?_set_online(), and which are common to roll back
from qeth_hardsetup_card().

Some steps (cancelling the RX modeset, draining the TX queues) are only
necessary if the netdev was potentially UP before, so move them to the
common qeth_set_offline().
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Move duplicated code from the disciplines into the core path.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Originators of cmd IO typically hold the rtnl or conf_mutex to protect
against a concurrent teardown.
Since qeth_set_offline() already holds the conf_mutex, the main reason
why we still care about cancelling pending cmds is so that they release
the rtnl when we need it ourselves.

So move this step a little earlier into the teardown sequence.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch detects whether device-to-bridge-notification, provided
by the Perform Network Subchannel Operation (PNSO) operation code
ADDR_INFO (OC3), is supported by this card. A following patch will
map this to the learning_sync bridgeport flag, so we store it in
priv->brport_hw_features in bridgeport flag format.

Only IQD cards provide PNSO.
There is a feature bit to indicate whether the machine provides OC3,
unfortunately it is not set on old machines.
So PNSO is called to find out. As this will disable notification
and is exclusive with bridgeport_notification, this must be done
during card initialisation before previous settings are restored.

PNSO functionality requires some configuration values that are added to
the qeth_card.info structure. Some helper functions are defined to fill
them out when the card is brought online and some other places are
adapted, that can also benefit from these fields.
Signed-off-by: NAlexandra Winter <wintera@linux.ibm.com>
Reviewed-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

queue->state is a ternary spinlock in disguise, used by
OSA's TX completion path to lock the Output Queue and flush any pending
packets on it to the device. If the Queue is already locked by our TX
code, setting the lock word to QETH_OUT_Q_LOCKED_FLUSH lets the TX
completion code move on - the TX path will later take care of things
when it unlocks the Queue.

This sort of DIY locking is a non-starter of course, just let the
TX completion path block on the spinlock when necessary. If that ends up
causing additional latency due to lock contention, then converting
the OSA path to use xmit_more is the right way to go forward.

Also slightly expand the locked section and capture all of
qeth_do_send_packet(), so that the update for the 'bufs_pack' statistics
is done race-free.

While reworking the TX completion path's code, remove a barrier() that
doesn't make any sense.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Avoid poking around in the delayed_work struct's internals.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-throughSigned-off-by: NGustavo A. R. Silva <gustavoars@kernel.org>

The (misplaced) comment doesn't make any sense, enforcing an
uninitialized RX buffer won't help with IRQ reduction.

So make the best use of all available RX buffers.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Running a RX refill outside of NAPI context is inherently racy, even
though the worker is only started for an entirely idle RX ring.
>From the moment that the worker has replenished parts of the RX ring,
the HW can use those RX buffers, raise an IRQ and cause our NAPI code to
run concurrently to the RX refill worker.

Instead let the worker schedule our NAPI instance, and refill the RX
ring from there. Keeping accurate count of how many buffers still need
to be refilled also removes some quirky arithmetic from the low-level
code.

Fixes: b3332930 ("qeth: add support for af_iucv HiperSockets transport")
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When preparing a buffer for RX refill, tolerate that it already has a
pool_entry attached. Otherwise we could easily leak such a pool_entry
when re-driving the RX refill after an error (from eg. do_qdio()).

This needs some minor adjustment in the code that drains RX buffer(s)
prior to RX refill and during teardown, so that ->pool_entry is NULLed
accordingly.

Fixes: 4a71df50 ("qeth: new qeth device driver")
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We're not modifying these data blobs, so mark them as constant.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

To keep track of the addresses programmed from an RX modeset, we have
two separate hashtables (L2: mac_htable, L3: ip_mc_htable).

These are never used at the same time, so unify them into a single
rx_mode_addrs hashtable.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

While initially just trying to fix up the indentation, condense a few
lines and get rid of a goto label.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use the correct struct member instead of hardcoding its offset.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use the correct helper for casting to a user pointer.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As the cmd IO path has learned to propagate errnos back to its callers,
let them deal with errors instead of trying to restore their previous
configuration from within the IO error path.

Also translate the HW error to a meaningful errno, instead of returning
-EIO for all cases (and don't map this to -EOPNOTSUPP later on...).

While at it, add a READ_ONCE() / WRITE_ONCE() pair to ensure that the
data path always sees a valid isolation mode during reconfiguration.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When qeth_set_access_ctrl_online() is called during the device's
initialization and discovers that isolation mode isn't supported, don't
clear the user's currently configured mode.
They intentionally choose to operate the device in this specific mode,
and degrading the isolation is not an option.

Only adjust the configuration when called via sysfs (ie. fallback = 1),
and here follow the common pattern and restore it from prev_isolation.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

A newly initialized device defaults to ISOLATION_MODE_NONE, don't bother
with programming this a second time.

Then remove the OSD/OSX check, it's already done in the sysfs path
whenever the user actually changes the configuration.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>