qeth_l3_send_ipa_arp_cmd() is merely a wrapper around
qeth_send_control_data() now. So push the length adjustment into
QETH_SETASS_BASE_LEN, and remove the wrapper. While at it, also remove
some redundant 0-initializations.

qeth_send_setassparms() requires that callers prepare their command
parameters, so that they can be copied into the parameter area in one
go. Skip the indirection, and just let callers set up the command
themselves.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Call qeth_prepare_ipa_cmd() during setup of a new IPA cmd buffer, so
that it is used for all commands. Thus ARP and SNMP requests don't have
to do their own initialization.

This will now also set the proper MPC protocol version for SNMP requests
on L2 devices.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since commit 82bf5c08 ("s390/qeth: add support for IPv6 TSO"),
qeth_xmit() also knows how to build TSO packets and is practically
identical to qeth_l3_xmit().
Convert qeth_l3_xmit() into a thin wrapper that merely strips the
L2 header off a packet, and calls qeth_xmit() for the actual
TX processing.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Filling the HW header from one single function will make it easier to
rip out all the duplicated transmit code in qeth_l3_xmit(). On top, this
saves one conditional branch in the TSO path.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The ARP_{ADD,REMOVE}_ENTRY cmd structs contain reserved fields.
Introduce a common helper that doesn't raw-copy the user-provided data
into the cmd, but only sets those fields that are strictly needed for
the command.

This also sets the correct command length for ARP_REMOVE_ENTRY.
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>

Sniffing mode for L3 HiperSockets requires that no IP addresses are
registered with the HW. The preferred way to achieve this is for
userspace to delete all the IPs on the interface. But qeth is expected
to also tolerate a configuration where that is not the case, by skipping
the IP registration when in sniffer mode.
Since commit 5f78e29c ("qeth: optimize IP handling in rx_mode callback")
reworked the IP registration logic in the L3 subdriver, this no longer
works. When the qeth device is set online, qeth_l3_recover_ip() now
unconditionally registers all unicast addresses from our internal
IP table.

While we could fix this particular problem by skipping
qeth_l3_recover_ip() on a sniffer device, the more future-proof change
is to skip the IP address registration at the lowest level. This way we
a) catch any future code path that attempts to register an IP address
   without considering the sniffer scenario, and
b) continue to build up our internal IP table, so that if sniffer mode
   is switched off later we can operate just like normal.

Fixes: 5f78e29c ("qeth: optimize IP handling in rx_mode callback")
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>

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>

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>

This patch attempts to untangle the TX and RX code in qeth from
af_iucv's respective HiperTransport path:
On the TX side, pointing skb_network_header() at the IUCV header
means that qeth_l3_fill_af_iucv_hdr() no longer needs a magical offset
to access the header.
On the RX side, qeth pulls the (fake) L2 header off the skb like any
normal ethernet driver would. This makes working with the IUCV header
in af_iucv easier, since we no longer have to assume a fixed skb layout.

While at it, replace the open-coded length checks in af_iucv's RX path
with pskb_may_pull().
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>

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>

Calling napi_schedule() from process context does not ensure that the
NET_RX softirq is run in a timely fashion. So trigger it manually.

This is no big issue with current code. A call to ndo_open() is usually
followed by a ndo_set_rx_mode() call, and for qeth this contains a
spin_unlock_bh(). Except for OSN, where qeth_l2_set_rx_mode() bails out
early.
Nevertheless it's best to not depend on this behaviour, and just fix
the issue at its source like all other drivers do. For instance see
commit 83a0c6e5 ("i40e: Invoke softirqs after napi_reschedule").

Fixes: a1c3ed4c ("qeth: NAPI support for l2 and l3 discipline")
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 HW header cache, it also
copies over the necessary protocol headers. Thus any manipulation to
the protocol headers needs to happen before adding the HW header.

For current usage this doesn't matter, but it becomes relevant when
moving TSO transmission over to the faster code path.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Combined L3+L4 csum offload is only required for some L3 HW. So for
L2 devices, don't offload the IP header csum calculation.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Reference-ID: JUP 394553
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>

qeth_l3_xmit() is now only used for TSOv4 traffic, shrink it down.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

L3 OSAs can only offload IPv4 traffic, use the common L2 transmit path
for all other traffic.
In particular there's no support for TX VLAN offload, so any such packet
needs to be manually de-accelerated via ndo_features_check().
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

For inbound data with an unsupported HW header format, only dump the
actual HW header. We have no idea how much payload follows it, and what
it contains. Worst case, we dump past the end of the Inbound Buffer and
access whatever is located next in memory.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Return statements in functions returning bool should use true or false
instead of an integer value.

This issue was detected with the help of Coccinelle.
Signed-off-by: NGustavo A. R. Silva <gustavo@embeddedor.com>
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>

Some transmit modes require that the HW header is located in the same
page as the initial protocol headers in skb->data. Let callers specify
the size of this contiguous header range, and enforce it when building
the HW header.

While at it, apply some gentle renaming to the relevant L2 code so that
it matches the L3 code.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When checking whether an skb needs to be linearized to fit into an IO
buffer, it's desirable to consider the skb's final size and layout
(ie. after the HW header was added). But a subsequent linearization can
then cause the re-positioned HW header to violate its alignment
restrictions.

Dealing with this situation in two different code paths is quite tricky.
This patch integrates a) linearize-check and b) HW header construction
into one 3 step-sequence:
1. evaluate how the HW header needs to be added (to identify if it takes
   up an additional buffer element), then
2. check if the required buffer elements exceed the device's limit.
   Linearize when necessary and re-evaluate the HW header placement.
3. Add the HW header in the best-possible way:
   a) push, without taking up an additional buffer element
   b) push, but consume another buffer element
   c) allocate a header object from the cache.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Nowadays an skb fragment typically spans over multiple pages. So replace
the obsolete, SG-only 'fragments' counter with one that tracks the
consumed buffer elements. This is what actually matters for performance.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

qeth's ndo_change_mtu() only applies some trivial bounds checking. Set
up dev->min_mtu properly, so that dev_set_mtu() can do this for us.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When the MPC initialization code discovers the HW-specific max MTU,
apply the resulting changes straight to the netdevice.

If this is the device's first initialization, also set its MTU
(HiperSockets: the max MTU; else: a layer-specific default value).
Then cap the current MTU by the new max MTU.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Allocation of the netdevice is currently delayed until a qeth card first
goes online. This complicates matters in several places, where we need
to cache values instead of applying them straight to the netdevice.

Improve on this by moving the allocation up to where the qeth card
itself is created. This is also one step in direction of eventually
placing the qeth card into netdev_priv().

In all subsequent code, remove the now redundant checks whether
card->dev is valid.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

netif_carrier_off() does its own checking.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Move the xmit of offload-eligible (ie IPv4) traffic on OSA over to the
new, copy-free path.
As with L2, we'll need to preserve the skb_orphan() behaviour of the
old code path until TX completion is sufficiently fast.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This implements a new xmit path for L3 HiperSockets, which carves the
HW header from skb headroom instead of allocating it from the hdr cache.
It also adds NETIF_F_SG support.

The delta in qeth_l3_xmit() is all just removal of IQD-specific code and
some minor consolidation.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In preparation for future work, move the high-level xmit work into a
separate wrapper. This matches the L2 xmit code.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When a L3 device doesn't offer TSO, allow the stack to build full-size
GSO skbs.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Consolidate duplicated code, fix the misuse of RTN_UNSPEC and simplify
the handling of non-unicast traffic on IQD devices.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Changing a device's address lists (or its promisc mode) already triggers
an RX modeset, there's no need to do it manually from the L2 driver's
ndo_vlan_rx_kill_vid() hook.

Also when setting a device online, dev_open() already calls
dev_set_rx_mode(). So a manual modeset is only necessary from the
recovery path.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>