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>

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>

This adds TSO6 support for L3 qeth devices.
Just like for standard IPv6 traffic, TSO6 doesn't use IP offload and
thus runs over the normal qeth_xmit() path.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

TSO6 requires the full programming sequence, and not just a simple
START command. This implements the additional ENABLE command, and adds
some sanity checks that were missing for the START command.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In preparation for IPv6 TSO, turn the protocol version into a parameter
for the TSO control code.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Functions qeth_get_ipa_msg and qeth_get_ipa_cmd_name are modifying
the last member of global arrays without any locking that I can see.
If two instances of either function are running at the same time,
it could cause a race ultimately leading to an array overrun (the
contents of the last entry of the array is the only guarantee that
the loop will ever stop).

Performing the lookups without modifying the arrays is admittedly
slower (two comparisons per iteration instead of one) but these
are operations which are rare (should only be needed in error
cases or when debugging, not during successful operation) and it
seems still less costly than introducing a mutex to protect the
arrays in question.

As a side bonus, it allows us to declare both arrays as const data.
Signed-off-by: NJean Delvare <jdelvare@suse.de>
Cc: Julian Wiedmann <jwi@linux.ibm.com>
Cc: Ursula Braun <ubraun@linux.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
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>

If qeth_check_ipa_data() consumed an event, there's no point in
processing it further. So drop it early, and make the surrounding code
a tiny bit more readable.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Pull one level of checking up into qeth_send_control_data_cb(), and
clean up an else-after-return. No functional change.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We have no code that is waiting for these events, so just drop them when
they arrive.
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>

The cdev-to-card translation walks through two layers of drvdata,
with no locking or refcounting (where eg. the ccwgroup core only
accesses a cdev's drvdata while holding the ccwlock).

This might be safe for now, but any careless usage of the helper has the
potential for subtle races and use-after-free's. Luckily there's only
one occurrence where we _really_ need it (in qeth_irq()), for any other
user we can just pass through an appropriate card pointer.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This allows us to remove the CARD_FROM_CDEV calls in the iob callbacks.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When not using the CQ, this allows us avoid the second skb queue walk
in qeth_release_skbs().
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This was presumably left over from back when qeth recursed into
dev_queue_xmit().
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

To match the use of __skb_queue_purge(), also make the skb's enqueue in
qeth_fill_buffer() lockless.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

qeth_core_probe_device() sets the gdev's drvdata, but doesn't reset it
on a subsequent error. Move the (re-)setting around a bit, so that it
happens symmetrically on allocating/freeing the qeth_card struct.

This is no actual problem, as the ccwgroup core will discard the gdev
on a probe error. But from qeth's perspective the gdev is an external
resource, so it's best to manage it cleanly.
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>

Consolidate declaration and initialization of a static variable.
While at it reduce its scope in qeth_core_load_discipline(), and simplify
the return logic accordingly.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

While the raw values are fixed due to their use in a sysfs attribute,
we can still use the proper QETH_DISCIPLINE_* enum within the driver.

Also move the initialization into qeth_set_initial_options(), along with
all other user-configurable fields.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

qeth_get_ipacmd_buffer() obtains its buffers for building IPA cmds from
__qeth_get_buffer(), where they are fully cleared. So get rid of all the
additional zero-ing in various other places.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

For quite a lot of code paths it's obvious that they will never run in
IRQ context. So replace their spin_lock_irqsave() calls with
spin_lock_irq().

While at it, get rid of the redundant card pointer in struct qeth_reply
that was used by qeth_send_control_data() to access the card's lock.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Assuming this was just a typo, as returning an actual negative value
from a cmd callback would make no sense either.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When setting up, qeth installs its IRQ handler on the ccw devices. But
the IRQ handler is not cleared on removal - so even after qeth yields
control of the ccw devices, spurious interrupts would still be presented
to us.

Make (de-)installation of the IRQ handler part of the ccw channel
setup/removal helpers, and while at it also add the appropriate locking.
Shift around qeth_setup_channel() to avoid a forward declaration for
qeth_irq().
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Restructure the OSN xmit path to handle misaligned HW headers properly,
without shifting the packet data around.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Switch TSO over to the faster transmit path, and remove all the unused
old TSO code.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add all the necessary TSO plumbing to the copy-less transmit path.
This includes calculating the right length of required protocol headers,
and always building a separate buffer element for the TSO headers.

A follow-up patch will then switch TSO traffic over to this path.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When qeth_add_hw_header() falls back to the header cache, ensure that
the requested length doesn't exceed the object size.

For current usage this is a no-brainer, but TSO transmission will
introduce protocol headers of varying length.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Convert the last remaining user of qeth_get_elements_no() to
qeth_count_elements(), so this helper can be removed.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We need the exact same transmit path for non-offload-eligible traffic on
L3 OSAs. So make it accessible from both sub-drivers.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

qeth_query_oat_command() currently allocates the kernel buffer for
the SIOC_QETH_QUERY_OAT ioctl with kzalloc. So on systems with
fragmented memory, large allocations may fail (eg. the qethqoat tool by
default uses 132KB).

Solve this issue by using vzalloc, backing the allocation with
non-contiguous memory.
Signed-off-by: NWenjia Zhang <wenjia@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>

Scatter-gather transmit brings a nice performance boost. Considering the
rather large MTU sizes at play, it's also totally the Right Thing To Do.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Bailing out on allocation error is nice, but we also need to tell the
ccwgroup core that creating the qeth groupdev failed.

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

Allocating the main qeth_card struct with GFP_DMA blocks us from moving
it into netdev_priv(). But the only reason why we need DMA memory is the
ccw1 structs embedded into each ccw channel. So extract those into
separate allocations, like we already do for the cmd buffers.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The qeth_card struct is kzalloc-ed, so remove all the redundant
0-initializations. While at it, split up what's left of
qeth_determine_card_type().
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The data channel currently doesn't need a setup operation, because we
don't use pre-allocated cmd buffers for its IO. But subsequent changes
will introduce further setup that also applies to the data channel.
This refactors things a bit, so that the new stuff can then be
automatically applied to all channels.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Re-work the helper a little bit, so that it can be used for all CCWs
that qeth issues.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Where possible use accessor macros and local pointers to access the ccw
channels. This makes it less likely to miss a spot.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Just a little code deduplication.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Modify the L2 OSA xmit path so that it also supports L2 IQD devices
(in particular, their HW header requirements). This allows IQD devices
to advertise NETIF_F_SG support, and eliminates the allocation overhead
for the HW header.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>