When setting a device online, both subdrivers have the same code to
program the HW trap and Isolation mode. Move that code into a single
place.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Without this patch, a command bit in the supported commands mask is only
ever set to unsupported during set online. If a command is ever marked as
unsupported (e.g. because of error during qeth_l2_vnicc_query_cmds),
subsequent successful initialization (offline/online) would not bring it
back.

Fixes: caa1f0b1 ("s390/qeth: add VNICC enable/disable support")
Signed-off-by: NAlexandra Winter <wintera@linux.ibm.com>
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>

Smatch discovered the use of uninitialized variable sup_cmds
in error paths.

Fixes: caa1f0b1 ("s390/qeth: add VNICC enable/disable support")
Signed-off-by: NAlexandra Winter <wintera@linux.ibm.com>
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>

This consolidates the SW statistics code, and improves it to
(1) account for the header overhead of each segment on a TSO skb,
(2) count dangling packets as in-error (during eg. shutdown), and
(3) only count offloads when the skb was successfully transmitted.

We also count each segment of an TSO skb as one packet - except for
tx_dropped, to be consistent with dev->tx_dropped.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We have logic to determine the desired promisc mode in _each_ code path.
Change things around so that there is a clean split between
(a) high-level code that selects the new mode, and (b) implementations
of the various mechanisms to program this mode.

This also keeps qeth_promisc_to_bridge() from polluting the debug logs
on each RX modeset.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: NAlexandra Winter <wintera@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When processing the reply for a vnicc cmd, there's no need to remember
which specific sub-cmd type we initially sent. The reply itself contains
all the needed information.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Except for card->read_cmd, every cmd we issue now passes through
qeth_send_control_data() and allocates a qeth_reply struct. The way we
use this struct requires additional refcounting, and pointer tracking.

Clean up things by moving most of qeth_reply's content into the main
cmd struct. This keeps things in one place, saves us the additional
refcounting and simplifies the overall code flow.
A nice little benefit is that we can now match incoming replies against
the pending requests themselves, without caching the requests' seqnos.

The qeth_reply struct stays around for a little bit longer in a shrunk
form, to avoid touching every single callback.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When an cmd IO completes in qeth_irq(), calculate how much data was
processed by the device and pass this value to the cmd's callback.

This allows cmds that retrieve data from the device to check whether
sufficient data was received, so we do that in qeth_read_conf_data_cb().
Suggested-by: NJens Remus <jremus@linux.ibm.com>
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Mark switch cases where we are expecting to fall through.

This patch fixes the following warnings (Building: s390):

drivers/s390/net/ctcm_fsms.c: In function ‘ctcmpc_chx_attnbusy’:
drivers/s390/net/ctcm_fsms.c:1703:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
   if (grp->changed_side == 1) {
      ^
drivers/s390/net/ctcm_fsms.c:1707:2: note: here
  case MPCG_STATE_XID0IOWAIX:
  ^~~~

drivers/s390/net/ctcm_mpc.c: In function ‘ctc_mpc_alloc_channel’:
drivers/s390/net/ctcm_mpc.c:358:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
   if (callback)
      ^
drivers/s390/net/ctcm_mpc.c:360:2: note: here
  case MPCG_STATE_XID0IOWAIT:
  ^~~~

drivers/s390/net/ctcm_mpc.c: In function ‘mpc_action_timeout’:
drivers/s390/net/ctcm_mpc.c:1469:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
   if ((fsm_getstate(rch->fsm) == CH_XID0_PENDING) &&
      ^
drivers/s390/net/ctcm_mpc.c:1472:2: note: here
  default:
  ^~~~~~~
drivers/s390/net/ctcm_mpc.c: In function ‘mpc_send_qllc_discontact’:
drivers/s390/net/ctcm_mpc.c:2087:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
   if (grp->estconnfunc) {
      ^
drivers/s390/net/ctcm_mpc.c:2092:2: note: here
  case MPCG_STATE_FLOWC:
  ^~~~

drivers/s390/net/qeth_l2_main.c: In function ‘qeth_l2_process_inbound_buffer’:
drivers/s390/net/qeth_l2_main.c:328:7: warning: this statement may fall through [-Wimplicit-fallthrough=]
    if (IS_OSN(card)) {
       ^
drivers/s390/net/qeth_l2_main.c:337:3: note: here
   default:
   ^~~~~~~
Reviewed-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NGustavo A. R. Silva <gustavo@embeddedor.com>

The cast type currently gets selected in .ndo_start_xmit, and is then
piped through several layers until it's stored into the HW header.
Push the selection down into qeth_l?_fill_header() to (1) reduce the
number of xmit-wide parameters, and (2) merge the two route validation
checks into just one.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

De-duplicate the pm callback implementations from the two sub-drivers,
replacing them with core helpers that delegate to the .set_online and
.set_offline callbacks.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Now that all cmds are dynamically allocated, the code for static cmd
buffers can go away entirely. Resulting in a nice reduction of
code/data size & complexity, while removing the risk that
qeth_clear_cmd_buffers() releases cmds that are still in-flight.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The VNICC code is somewhat quirky in that it defers the whole cmd setup
to a common helper qeth_l2_vnicc_request(). Some of the cmd specifics
are then passed in via parameter, while others are simply hard-coded.

Split the whole machinery up into the usual format: one helper that
allocates the cmd & fills in the common fields, while all the cmd
originators take care of their sub-cmd type specific work.
This makes it much easier to calculate the cmd's precise length, and
reduces code complexity.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: NAlexandra Winter <wintera@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch converts the adapter, assist and bridgeport cmd paths to
dynamic allocation. Most of the work is about re-organizing the cmd
headers, calculating the correct cmd length, and filling in the right
value in the sub-cmd's length field.

Since we now also set the correct length for cmds that are not reflected
by a fixed struct (ie SNMP), we can remove the work-around from
qeth_snmp_command().
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch reduces the usage of the write channel's static cmd buffers,
by dynamically allocating all simple IPA cmds (eg. STARTLAN, SETVMAC).
It also converts the OSN path.

Doing so requires some changes to how we calculate the cmd length.
Currently when building IPA cmds, we're quite generous in how much data
we send down to the device (basically the size of the biggest cmd we
know). This is no real concern at the moment, since the static cmd
buffers are backed with zeroed pages. But for dynamic allocations, the
exact length matters. So this patch also adds the needed length
calculations to each cmd path.

Commands that have multiple subtypes (eg. SETADP) of differing length
will be converted with follow-up patches.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We statically allocate 8 cmd buffers on the read channel, when the only
IO left that's still using them is the long-running READ.
Replace this with a single allocated cmd, that gets restarted whenever
the READ completed.

This introduces refcounting for allocated cmds, so that the READ cmd can
survive the IO completion.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Each cmd buffer maintains a pointer to the IO channel that it was/will
be issued on. So when dealing with cmd buffers, we don't need to pass
around a separate channel pointer.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The vast majority of SETUP-classified trace entries can be moved to
their device-specific trace file. This reduces pollution of the global
SETUP file, and provides a consistent trace view of all activity on the
device.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

OSN currently provides a custom code path to submit IPA cmds, without
waiting for the cmd response. Replace it with qeth_send_ipa_cmd(), which
uses the common qeth_send_control_data() IO infrastructure.

By setting a custom iob->callback, we can now provide feedback to the
caller about whether the cmd has been successfully submitted to HW.
Since the callback then immediately wakes up the reply-waiter object, we
maintain the old behaviour of returning early without waiting for the
response.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The basic MPC initialization sequence is strictly sequential, and
waiting for an available cmd buffer should never be necessary.
So this change only affects the OSN path, where dangling waiters on an
unbounded wait_event() are not desirable. Switch to qeth_get_buffers(),
and let OSN callers deal with -ENOMEM.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When the tear down sequence in qeth_l?_stop_card() has finished, the
card is guaranteed to be in DOWN state and we don't have to check for
it again.
With this insight we can also remove the redundant setting of
card->state in qeth_l?_set_online()'s error path.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Enabling sysfs attribute bridge_hostnotify triggers a series of udev events
for the MAC addresses of all currently connected peers. In case no VLAN is
set for a peer, the device reports the corresponding MAC addresses with
VLAN ID 4096. This currently results in attribute VLAN=4096 for all
non-VLAN interfaces in the initial series of events after host-notify is
enabled.

Instead, no VLAN attribute should be reported in the udev event for
non-VLAN interfaces.

Only the initial events face this issue. For dynamic changes that are
reported later, the device uses a validity flag.

This also changes the code so that it now sets the VLAN attribute for
MAC addresses with VID 0. On Linux, no qeth interface will ever be
registered with VID 0: Linux kernel registers VID 0 on all network
interfaces initially, but qeth will drop .ndo_vlan_rx_add_vid for VID 0.
Peers with other OSs could register MACs with VID 0.

Fixes: 9f48b9db ("qeth: bridgeport support - address notifications")
Signed-off-by: NAlexandra Winter <wintera@linux.ibm.com>
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This de-duplicates the L2 and L3 cast-type code, and makes the L2 code
a bit more robust by removing the fragile assumption that skb->data
always points to the Ethernet Header. This would break in code paths
where we pushed the HW header onto the skb.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The QETH_MAX_BUFFER_ELEMENTS() macro effectively returns a constant
value. To avoid some redundant pointer chasing and computations in the
xmit hot path, cache this value in the queue struct.

Take this as opportunity to shrink some of the queue struct's fields to
their appropriate value range, slightly reducing its total size.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We have helper macros for all possible device types, replace all
remaining open-coded accesses to the type fields.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

It's unclear what exact purpose this seqno may have served in the past.
But it's certainly no longer used anymore, as the following
napi_gro_receive() will straight away clear this part of the cb again.
Suggested-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>

Current xmit code only stops the txq after attempting to fill an
IO buffer that hasn't been TX-completed yet. In many-connection
scenarios, this can result in frequent rejected TX attempts, requeuing
of skbs with NETDEV_TX_BUSY and extra overhead.

Now that we have a proper 1-to-1 relation between stack-side txqs and
our HW Queues, overhaul the stop/wake logic so that the xmit code
stops the txq as needed.
Given that we might map multiple skbs into a single buffer, it's crucial
to ensure that the queue always provides an _entirely_ empty IO buffer.
Otherwise large skbs (eg TSO) might not fit into the last available
buffer. So whenever qeth_do_send_packet() first utilizes an _empty_
buffer, it updates & checks the used_buffers count.

This now ensures that an skb passed to qeth_xmit() can always be mapped
into an IO buffer, so remove all of the -EBUSY roll-back handling in the
TX path. We preserve the minimal safety-checks ("Is this IO buffer
really available?"), just in case some nasty future bug ever attempts to
corrupt an in-use buffer.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This adds trivial support for multiple TX queues on OSA-style devices
(both real HW and z/VM NICs). For now we expose the driver's existing
QoS mechanism via .ndo_select_queue, and adjust the number of available
TX queues when qeth_update_from_chp_desc() detects that the
HW configuration has changed.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

qeth has been supporting multiple HW Output Queues for a long time. But
rather than exposing those queues to the stack, it uses its own queue
selection logic in .ndo_start_xmit... with all the drawbacks that
entails.
Start off by switching IQD devices over to a proper mqs net_device,
and converting all the netdev_queue management code.

One oddity with IQD devices is the requirement to place all mcast
traffic on the _highest_ established HW queue. Doing so via
.ndo_select_queue seems straight-forward - but that won't work if only
some of the HW queues are active
(ie. when dev->real_num_tx_queues < dev->num_tx_queues), since
netdev_cap_txqueue() will not allow us to put skbs on the higher queues.

To make this work, we
1. let .ndo_select_queue() map all mcast traffic to netdev_queue 0, and
2. later re-map the netdev_queue and HW queue indices in
   .ndo_start_xmit and the TX completion handler.

With this patch we default to a fixed set of 1 ucast and 1 mcast queue.
Support for dynamic reconfiguration is added at a later time.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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>