The naming of several QDIO helpers doesn't match their actual
functionality, or the structures they operate on. Clean this up.

s/qeth_alloc_qdio_buffers/qeth_alloc_qdio_queues
s/qeth_free_qdio_buffers/qeth_free_qdio_queues
s/qeth_alloc_qdio_out_buf/qeth_alloc_output_queue
s/qeth_clear_outq_buffers/qeth_drain_output_queue
s/qeth_clear_qdio_buffers/qeth_drain_output_queues
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

To avoid concurrency issues, some parts of the cmd setup are delayed
until qeth_send_control_data() holds the IO channel's irq_pending
"lock". Rather than hard-coding those setup steps for each cmd type,
have the cmd provide a callback. This will make it easier to also issue
IDX commands via qeth_send_control_data().
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

All callers are running in process context now, so we can safely sleep
in qeth_send_control_data() while waiting for a cmd to complete.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The L2 and L3 .ndo_set_rx_mode callbacks maintain an address cache
to decide which addresses have changed since the last modeset.

When the card is set offline, qeth_l?_stop_card() drains this cache.
This happens only after 1) the net_device has been detached, and
2) any pending RX modeset has completed. Consequently we can access the
cache lock-free.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

.ndo_set_rx_mode gets called in process context, but while holding the
addr_list spinlock. Which means we currently can't sleep while
re-programming the HW, and need to poll for IO completion. That's bad,
in particular since receiving the cmd response can fail silently and
we're then polling until the timeout hits.

As a first step towards eliminating the IO completion polling, run the
RX modeset from a work element and only take the addr_list lock while
updating the RX mode address cache.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As part of the TX completion path, qeth_release_skbs() frees the completed
skbs with __skb_queue_purge(). This ends in kfree_skb(), reporting every
completed skb as dropped.
On the other hand when dropping an skb in .ndo_start_xmit, we end up
calling consume_skb()... where we should be using kfree_skb() so that
drop monitors get notified.

Switch the drop/consume logic around, and also don't accumulate dropped
packets in the tx_errors statistics.

Fixes: dc149e37 ("s390/qeth: replace open-coded skb_queue_walk()")
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The HW trap and VNICC configuration is exposed via sysfs, and may have
already been modified when qeth_l?_probe_device() attempts to initialize
them. So (1) initialize the VNICC values a little earlier, and (2) don't
bother about the HW trap mode, it was already initialized before.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Now that qeth always uses dev_close() to shutdown the interface, we can
trust the locking and remove some custom state checks.
qeth_l?_stop_card() is no longer called for a card in UP state, so remove
the checks there too. This basically makes the UP state obsolete, so rip
out the whole thing (except for the sysfs-visible string).
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

It makes no difference whether we
1. manually disarm the HW trap and call the offline code with
   recovery_mode == 1, or
2. call the offline code with recovery_mode == 0, and let it disarm the
   HW trap for us.

So consolidate the two code paths in the suspend callback.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The recovery code already runs in a kthread, we don't have to defer the
offlining further.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When resetting an interface ("recovery"), qeth currently attempts to
elide the call to dev_close(). We initially only call .ndo_close to
quiesce the data path, and then offline & online the ccwgroup device.
If the reset succeeded, a call to .ndo_open then resumes the data path
along with some internal setup (dev_addr validation, RX modeset) that
dev_open() would have usually triggered.
dev_close() only gets called (via the close_dev worker) if the reset
action fails.

It's unclear whether this was initially done due to locking concerns, or
rather to execute the reset transparently. Either way, temporarily
closing the interface without dev_close() is fragile, and means we're
susceptible to various races and unexpected behaviour. For instance:

- Bypassing dev_deactivate_many() means that the qdiscs are not set to
__QDISC_STATE_DEACTIVATED. Consequently any intermittent TX completion
can wake up the txq, resulting in calls to .ndo_start_xmit while the
data path is down. We have custom state checking to detect this case
and drop such packets.

- Because the IFF_UP flag doesn't reflect the interface's actual state
during a reset, we have custom state checking in .ndo_open and
.ndo_close to guard against invalid calls.

- Considering that the reset might take a considerable amount of time
(in particular if an IO fails and we end up waiting for its timeout), we
_do_ want NETDEV_GOING_DOWN and NETDEV_DOWN events so that components
like bonding, team, bridge, macvlan, vlan, ... can take appropriate
action.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In its attempt to run only the minimal amount of tear down steps,
qeth_l2_stop_card() fails to reset the "is dev_addr registered?" flag
in some rare scenarios. But a future change to the tear down sequence
would cause us to _always_ hit this issue, so patch it up before that
code lands.

Fix it by unconditionally clearing the flag bit. This also allows us to
remove the additional cleanup step in qeth_dev_layer2_store().
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When setting a L2 qeth device online, enable the HW trap as soon as the
control plane is available. This allows us to catch any error that
occurs during the very first commands.

In the same spirit, the offline code should disable the HW trap as the
very first step of its processing.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The offline code uses a specific RECOVER state to indicate that the
interface should be brought up when a qeth device is set online again.

Rather than having a specific card-state for this, just put it in an
internal flag bit and set the state to DOWN. When working with the
card's state transitions, this reduces the complexity quite a bit.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Rather than special-casing OSN in a number of places, just give this
device type its own netdev_ops structure.

When setting up the OSN net_device, also skip the handling of the
various HW offloads (eg TSO). The device shouldn't be advertising any of
them, and the OSN code paths in qeth don't have support for them.
In particular RX VLAN filtering is not supported, so don't hook up those
callbacks in the netdev_ops.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Accumulate per-TX queue statistics, and increase their size to 64 bit.
Don't bother with enabling/disabling the statistics, the overhead is
negligible.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Most of this is self-contained code.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Counting the number of function calls and the time spent in functions
is best left to proper tracing facilities.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This calls the existing errno translation helpers from the callbacks,
adding trivial wrappers where necessary. For cmds that have no
sophisticated errno translation, default to -EIO.

For IPA cmds with no callback, fall back to a minimal default. This is
currently being used by qeth_l3_send_setrouting().

Thus having all converted all callbacks, remove the legacy path in
qeth_send_control_data_cb().
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

By letting the callbacks deal with error translation, we no longer need
to pass the raw error codes back to the originator. This allows us to
slim down the callback's private data, and nicely simplifies the code.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Error propagation from cmd callbacks currently works in a way where
qeth_send_control_data_cb() picks the raw HW code from the response,
and the cmd's originator later translates this into an errno.
The callback itself only returns 0 ("done") or 1 ("expect more data").

This is
1. limiting, as the only means for the callback to report an internal
error is to invent pseudo HW codes (such as IPA_RC_ENOMEM), that
the originator then needs to understand. For non-IPA callbacks, we
even provide a separate field in the IO buffer metadata (iob->rc) so
the callback can pass back a return value.
2. fragile, as the originator must take care to not translate any errno
that is returned by qeth's own IO code paths (eg -ENOMEM). Also, any
originator that forgets to translate the HW codes potentially passes
garbage back to its caller. For instance, see
commit 2aa48671 ("s390/qeth: translate SETVLAN/DELVLAN errors").

Introduce a new model where all HW error translation is done within the
callback, and the callback returns
>  0, if it expects more data (as before)
== 0, on success
<  0, with an errno

Start off with converting all callbacks to the new model that either
a) pass back pseudo HW codes, or b) have a dependency on a specific
HW error code. Also convert c) the one callback that uses iob->rc, and
d) qeth_setadpparms_change_macaddr_cb() so that it can pass back an
error back to qeth_l2_request_initial_mac() even when the cmd itself
was successful.

The old model remains supported: if the callback returns 0, we still
propagate the response's HW error code back to the originator.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The code to fill the IPA length fields is duplicated three times across
the driver:
1. qeth_send_ipa_cmd() sets IPA_CMD_LENGTH, which matches the defaults
   in the IPA_PDU_HEADER template.
2. for OSN, qeth_osn_send_ipa_cmd() bypasses this logic and inserts the
   length passed by the caller.
3. SNMP commands (that can outgrow IPA_CMD_LENGTH) have their own way
   of setting the length fields, via qeth_send_ipa_snmp_cmd().

Consolidate this into qeth_prepare_ipa_cmd(), which all originators of
IPA cmds already call during setup of their cmd. Let qeth_send_ipa_cmd()
pull the length from the cmd instead of hard-coding IPA_CMD_LENGTH.

For now, the SNMP code still needs to fix-up its length fields manually.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Work for Bridgeport events is currently placed on a driver-wide
workqueue. If the card is removed and freed while any such work is still
active, this causes a use-after-free.
So put the events on a per-card queue, where we can control their
lifetime. As we also don't want stale events to last beyond an
offline & online cycle, flush this queue when setting the card offline.

Fixes: b4d72c08 ("qeth: bridgeport support - basic control")
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

A card's close_dev work is scheduled on a driver-wide workqueue. If the
card is removed and freed while the work is still active, this causes a
use-after-free.
So make sure that the work is completed before freeing the card.

Fixes: 0f54761d ("qeth: Support VEPA mode")
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

For recovery purposes, qeth keeps track of all registered VIDs. Replace
this by using the infrastructure introduced in
commit 9daae9bd ("net: Call add/kill vid ndo on vlan filter feature toggling").

By managing NETIF_F_HW_VLAN_CTAG_FILTER as a hw_feature,
netdev_update_features() will select it from dev->wanted_features
and replay all of the netdevice's VIDs to its ndo_vlan_rx_add_vid()
callback.
z/VM NICs strictly require VLAN registration, so don't expose it as
hw_feature there but add a little hack in qeth_enable_hw_features()
to make things work regardless.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When a qeth card is offline, it has no connection to the HW. So none of
our control callbacks can run IO against it, and we can only cache the
input (eg a new MAC address) without providing proper feedback to the
caller. In this context, it seems much more reasonable to simply detach
the netdevice and let the kernel reject any interaction with it.

This also makes all sorts of internal state checks and locking obsolete.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Re-order the code flow a bit so that all initial HW setup is done before
putting the netdevice into play. For a netdevice that hasn't been
registered before, we also don't need to re-enable its HW features or
check for recovery actions.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

At best this is redundant, at worst it papers over a race in the
offline / online code.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

commit 4789a218 ("s390/qeth: fix race when setting MAC address")
resolved a race where our initial programming of dev_addr into the HW
and a call to ndo_set_mac_address() could run concurrently. In this
case, we could end up getting confused about which address was actually
set in the HW.

The quick fix was to introduce additional locking that blocks any
ndo_set_mac_address() while the device is being set online. But the race
primarily originated from the fact that we first register the netdevice,
and only then program its dev_addr. By re-ordering this sequence,
userspace will only be able to change the MAC address _after_ we have
finished with setting the initial dev_addr.

Still, the same MAC address race can also occur during a subsequent call
to qeth_l2_set_online(). So keep around the locking for now, until a
follow-up patch fully resolves this.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The L2 and L3 code for these ops is almost identical, we only need to
provide a custom ndo_validate_addr() for L2 that checks whether
programming the MAC address succeeded.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In order to pass extack together with NETDEV_PRE_UP notifications, it's
necessary to route the extack to __dev_open() from diverse (possibly
indirect) callers. One prominent API through which the notification is
invoked is dev_open().

Therefore extend dev_open() with and extra extack argument and update
all users. Most of the calls end up just encoding NULL, but bond and
team drivers have the extack readily available.
Signed-off-by: NPetr Machata <petrm@mellanox.com>
Acked-by: NJiri Pirko <jiri@mellanox.com>
Reviewed-by: NIdo Schimmel <idosch@mellanox.com>
Reviewed-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Re-implement the card-by-RDEV lookup by using device model concepts, and
remove the now redundant list of all qeth card instances in the system.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

By default, READ MAC on a Layer2 OSD device returns the adapter's
burnt-in MAC address. Given the default scenario of many virtual devices
on the same adapter, qeth can't make any use of this address and
therefore skips the READ MAC call for this device type.

But in some configurations, the READ MAC command for a Layer2 OSD device
actually returns a pre-provisioned, virtual MAC address. So enable the
READ MAC code to detect this situation, and let the L2 subdriver
call READ MAC for OSD devices.

This also removes the QETH_LAYER2_MAC_READ flag, which protects L2
devices against calling READ MAC multiple times. Instead protect the
whole call to qeth_l2_request_initial_mac().
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Setting the carrier 'on' for an unregistered netdevice doesn't update
its operstate. Fix this by delaying the update until the netdevice has
been registered.

Fixes: 91cc98f5 ("s390/qeth: remove duplicated carrier state tracking")
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

qeth only registers its netdevice when the qeth device is first set
online. Thus a device that has never been set online will trigger
a WARN ("network todo 'hsi%d' but state 0") in unregister_netdev() when
removed.

Fix this by protecting the unregister step, just like we already protect
against repeated registering of the netdevice.

Fixes: d3d1b205 ("s390/qeth: allocate netdevice early")
Reported-by: NKarsten Graul <kgraul@linux.ibm.com>
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As Documentation/s390/s390dbf.txt states quite clearly, using any
pointer in sprinf-formatted s390dbf debug entries is dangerous.
The pointers are dereferenced whenever the trace file is read from.
So if the referenced data has a shorter life-time than the trace file,
any read operation can result in a use-after-free.

So rip out all hazardous use of indirect data, and replace any usage of
dev_name() and such by the Bus ID number.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Except for the new HW header id, this works just like TSO6 on L3 devices
and reuses all the existing data path support in qeth_xmit().
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The netdevice is always available, apply any carrier state changes to it
without caching them.
On a STARTLAN event (ie. carrier-up), defer updating the state to
qeth_core_hardsetup_card() in the subsequent recovery action.

Also remove the carrier-state checks from the xmit routines. Stopping
transmission on carrier-down is the responsibility of upper-level code
(eg see dev_direct_xmit()).
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

1. tracing iob->rc makes no sense when it hasn't been modified by the
   callback,
2. the qeth_dbf_list is declared with LIST_HEAD, which also initializes
   the list,
3. the ccwgroup core only calls the thaw/restore callbacks if the gdev
   is online, so we don't have to check for it again.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Device initialization code usually first loads a subdriver
(via qeth_core_load_discipline()), and then runs its setup() callback.
If this fails, it rolls back the load via qeth_core_free_discipline().

qeth_core_free_discipline() expects the options.layer attribute to be
initialized, but on error in setup() that's currently not the case.
Resulting in misbalanced symbol_put() calls.

Fix this by setting options.layer when loading the subdriver.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>