s390/qeth: Convert sysfs sprintf to sysfs_emit

Following the advice of the Documentation/filesystems/sysfs.rst.
All sysfs related show()-functions should only use sysfs_emit() or
sysfs_emit_at() when formatting the value to be returned to user space.

Reported-by: Jules Irenge <jbi.octave@gmail.com>
Reported-by: Joe Perches <joe@perches.com>
Reviewed-by: Alexandra Winter <wintera@linux.ibm.com>
Signed-off-by: Thorsten Winkler <twinkler@linux.ibm.com>
Signed-off-by: Alexandra Winter <wintera@linux.ibm.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

s390/qeth: use dev->groups for common sysfs attributes

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: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

s390/qeth: Reset address notification in case of buffer overflow

In case hardware sends more device-to-bridge-address-change notfications
than the qeth-l2 driver can handle, the hardware will send an overflow
event and then stop sending any events. It expects software to flush its
FDB and start over again. Re-enabling address-change-notification will
report all current addresses.

In order to re-enable address-change-notification this patch defines
the functions qeth_l2_dev2br_an_set() and qeth_l2_dev2br_an_set_cb
to enable or disable dev-to-bridge-address-notification.

A following patch will use the learning_sync bridgeport flag to trigger
enabling or disabling of address-change-notification, so we define
priv->brport_features to store the current setting. BRIDGE_INFO and
ADDR_INFO functionality are mutually exclusive, whereas ADDR_INFO and
qeth_l2_vnicc* can be used together.

Alternative implementations to handle buffer overflow:
Just re-enabling notification and adding all newly reported addresses
would cover any lost 'add' events, but not the lost 'delete' events.
Then these invalid addresses would stay in the bridge FDB as long as the
device exists.
Setting the net device down and up, would be an alternative, but is a bit
drastic. If the net device has many secondary addresses this will create
many delete/add events at its peers which could de-stabilize the
network segment.

Signed-off-by: Alexandra Winter <wintera@linux.ibm.com>
Reviewed-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

s390/qeth: strictly order bridge address events

The current code for bridge address events has two shortcomings in its
control sequence:

1. after disabling address events via PNSO, we don't flush the remaining
events from the event_wq. So if the feature is re-enabled fast
enough, stale events could leak over.
2. PNSO and the events' arrival via the READ ccw device are unordered.
So even if we flushed the workqueue, it's difficult to say whether
the READ device might produce more events onto the workqueue
afterwards.

Fix this by
1. explicitly fencing off the events when we no longer care, in the
READ device's event handler. This ensures that once we flush the
workqueue, it doesn't get additional address events.
2. Flush the workqueue after disabling the events & fencing them off.
As the code that triggers the flush will typically hold the sbp_lock,
we need to rework the worker code to avoid a deadlock here in case
of a 'notifications-stopped' event. In case of lock contention,
requeue such an event with a delay. We'll eventually aquire the lock,
or spot that the feature has been disabled and the event can thus be
discarded.

This leaves the theoretical race that a stale event could arrive
_after_ we re-enabled ourselves to receive events again. Such an event
would be impossible to distinguish from a 'good' event, nothing we can
do about it.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Alexandra Winter <wintera@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

s390/qeth: shift some bridgeport code around

qeth_l2_setup_bridgeport_attrs() is entirely unrelated to sysfs
functionality, move it where it belongs.
While at it merge all the bridgeport-specific code in the set-online
path together.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Alexandra Winter <wintera@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

s390/qeth: fix promiscuous mode after reset

When managing the promiscuous mode during an RX modeset, qeth caches the
current HW state to avoid repeated programming of the same state on each
modeset.

But while tearing down a device, we forget to clear the cached state. So
when the device is later set online again, the initial RX modeset
doesn't program the promiscuous mode since we believe it is already
enabled.
Fix this by clearing the cached state in the tear-down path.

Note that for the SBP variant of promiscuous mode, this accidentally
works right now because we unconditionally restore the SBP role while
re-initializing.

Fixes: 4a71df50047f ("qeth: new qeth device driver")
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Alexandra Winter <wintera@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

s390/qeth: fix potential deadlock on workqueue flush

The L2 bridgeport code uses the coarse 'conf_mutex' for guarding access
to its configuration state.
This can result in a deadlock when qeth_l2_stop_card() - called under the
conf_mutex - blocks on flush_workqueue() to wait for the completion of
pending bridgeport workers. Such workers would also need to aquire
the conf_mutex, stalling indefinitely.

Introduce a lock that specifically guards the bridgeport configuration,
so that the workers no longer need the conf_mutex.
Wrapping qeth_l2_promisc_to_bridge() in this fine-grained lock then also
fixes a theoretical race against a concurrent qeth_bridge_port_role_store()
operation.

Fixes: c0a2e4d10d93 ("s390/qeth: conclude all event processing before offlining a card")
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Alexandra Winter <wintera@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

s390/qeth: don't check drvdata in sysfs code

Given the way how the sysfs attributes are registered / unregistered,
the show/store helpers will never be called with a NULL drvdata.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.

For non */uapi/* files that summary was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139

and resulted in the first patch in this series.

If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930

and resulted in the second patch in this series.

- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:

SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1

and that resulted in the third patch in this series.

- when the two scanners agreed on the detected license(s), that became
the concluded license(s).

- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.

- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).

- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.

- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct

This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

s390/qeth: use kstrtobool() in qeth_bridgeport_hostnotification_store()

The sysfs enabled value is a boolean, so kstrtobool() is a better fit
for parsing the input string since it does the range checking for us.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Julian Wiedmann <jwi@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

s390/qeth: add VNICC get/set timeout support

HiperSockets allow configuring so called VNIC Characteristics (VNICC)
that influence how the underlying hardware handles packets. For VNICCs,
additional commands for getting and setting timeouts are available.
Currently, the learning VNICC uses these commands.

* Learning VNICC: If learning is enabled on a qeth device, the device
learns the source MAC addresses of outgoing packets and incoming
packets to those learned MAC addresses are received.

For learning, the timeout specifies the idle period in seconds, after
which the underlying hardware removes a learned MAC address again.

This patch adds support for the IPA commands that are required to get
and set the current timeout values for the learning VNIC characteristic.
Also, it introduces the sysfs interface that allows users to configure
the timeout.

Signed-off-by: Hans Wippel <hwippel@linux.vnet.ibm.com>
Reviewed-by: Julian Wiedmann <jwi@linux.vnet.ibm.com>
Signed-off-by: Julian Wiedmann <jwi@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

s390/qeth: add VNICC enable/disable support

HiperSocket devices allow enabling and disabling so called VNIC
Characteristics (VNICC) that influence how the underlying hardware
handles packets. These VNICCs are:

* Flooding VNICC: Flooding allows specifying if packets to unknown
destination MAC addresses are received by the qeth device.

* Multicast flooding VNICC: Multicast flooding allows specifying if
packets to multicast MAC addresses are received by the qeth device.

* Learning VNICC: If learning is enabled on a qeth device, the device
learns the source MAC addresses of outgoing packets and incoming
packets to those learned MAC addresses are received.

* Takeover setvmac VNICC: If takeover setvmac is configured on a qeth
device, the MAC address of this device can be configured on a
different qeth device with the setvmac IPA command.

* Takeover by learning VNICC: If takeover learning is enabled on a qeth
device, the MAC address of this device can be learned (learning VNICC)
on a different qeth device.

* BridgePort invisible VNICC: If BridgePort invisible is enabled on a
qeth device, (1) packets from this device are not sent to a BridgePort
enabled qeth device and (2) packets coming from a BridgePort enabled
qeth device are not received by this device.

* Receive broadcast VNICC: Receive broadcast allows configuring if a
qeth device receives packets with the broadcast destination MAC
address.

This patch adds support for the IPA commands that are required to enable
and disable these VNIC characteristics on qeth devices. As a
prerequisite, it also adds the query commands IPA command.

The query commands IPA command allows requesting the supported commands
for each characteristic from the underlying hardware.

Additionally, this patch provides users with a sysfs user interface to
enable/disable the VNICCs mentioned above.

Signed-off-by: Hans Wippel <hwippel@linux.vnet.ibm.com>
Reviewed-by: Julian Wiedmann <jwi@linux.vnet.ibm.com>
Signed-off-by: Julian Wiedmann <jwi@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

s390/qeth: unbreak OSM and OSN support

commit b4d72c08b358 ("qeth: bridgeport support - basic control")
broke the support for OSM and OSN devices as follows:

As OSM and OSN are L2 only, qeth_core_probe_device() does an early
setup by loading the l2 discipline and calling qeth_l2_probe_device().
In this context, adding the l2-specific bridgeport sysfs attributes
via qeth_l2_create_device_attributes() hits a BUG_ON in fs/sysfs/group.c,
since the basic sysfs infrastructure for the device hasn't been
established yet.

Note that OSN actually has its own unique sysfs attributes
(qeth_osn_devtype), so the additional attributes shouldn't be created
at all.
For OSM, add a new qeth_l2_devtype that contains all the common
and l2-specific sysfs attributes.
When qeth_core_probe_device() does early setup for OSM or OSN, assign
the corresponding devtype so that the ccwgroup probe code creates the
full set of sysfs attributes.
This allows us to skip qeth_l2_create_device_attributes() in case
of an early setup.

Any device that can't do early setup will initially have only the
generic sysfs attributes, and when it's probed later
qeth_l2_probe_device() adds the l2-specific attributes.

If an early-setup device is removed (by calling ccwgroup_ungroup()),
device_unregister() will - using the devtype - delete the
l2-specific attributes before qeth_l2_remove_device() is called.
So make sure to not remove them twice.

What complicates the issue is that qeth_l2_probe_device() and
qeth_l2_remove_device() is also called on a device when its
layer2 attribute changes (ie. its layer mode is switched).
For early-setup devices this wouldn't work properly - we wouldn't
remove the l2-specific attributes when switching to L3.
But switching the layer mode doesn't actually make any sense;
we already decided that the device can only operate in L2!
So just refuse to switch the layer mode on such devices. Note that
OSN doesn't have a layer2 attribute, so we only need to special-case
OSM.

Based on an initial patch by Ursula Braun.

Fixes: b4d72c08b358 ("qeth: bridgeport support - basic control")
Signed-off-by: Julian Wiedmann <jwi@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

s390/qeth: Remove unused code

1. options.add_hhlen is set but never used, drop it
2. clean up no longer required forward declarations
3. delete all sorts of unused defines

Signed-off-by: Julian Wiedmann <jwi@linux.vnet.ibm.com>
Reviewed-by: Thomas Richter <tmricht@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

qeth: no write permission for readonly sysattr

User is not allowed to write into bridge_state sysfs file.
Fixed attribute not mislead the user

Signed-off-by: Lakhvich Dmitriy <ldmitriy@ru.ibm.com>
Signed-off-by: Ursula Braun <ursula.braun@de.ibm.com>
Reported-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Reviewed-by: Eugene Crosser <Eugene.Crosser@ru.ibm.com>
Reviewed-by: Thomas Richter <tmricht@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

qeth: BRIDGEPORT "sanity check"

Forbid enabling IFF_PROMISC reflection to BRIDGEPORT when a role
is already assigned, and forbid direct manipulation of the role
when reflection mode is engaged.

Reviewed-by: Thomas Richter <tmricht@linux.vnet.ibm.com>
Signed-off-by: Eugene Crosser <Eugene.Crosser@ru.ibm.com>
Signed-off-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

qeth: IFF_PROMISC flag to BRIDGE PORT mode

OSA and HiperSocket devices do not support promiscuous mode proper,
but they support "BRIDGE PORT" mode that is functionally similar.
This update introduces sysfs attribute that, when set, makes the driver
try to "reflect" setting and resetting of the IFF_PROMISC flag on the
interface into setting and resetting PRIMARY or SECONDARY bridge port
role on the underlying OSA or HiperSocket device.

Reviewed-by: Thomas Richter <tmricht@linux.vnet.ibm.com>
Signed-off-by: Eugene Crosser <Eugene.Crosser@ru.ibm.com>
Signed-off-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

qeth: remove locks from sysfs _show

Locking is probably unnecessary in this case, and the rest of the
qeth sysfs code does not use locks in the *_show() functions.
Remove locks from the layer2 *_show() functions in which they where
accidentally introduced.

Signed-off-by: Eugene Crosser <Eugene.Crosser@ru.ibm.com>
Signed-off-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

qeth: don't query for info if hardware not ready.

When qeth device is queried for ethtool data, hardware operation
is performed to extract the necessary information from the card.
If the card is not online at the moment (e.g. it is undergoing
recovery), this operation produces undesired effects like
temporarily freezing the system. This patch prevents execution
of the hardware query operation when the card is not online.
In such case, ioctl() operation returns error with errno ENODEV.

Reviewed-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: Eugene Crosser <Eugene.Crosser@ru.ibm.com>
Signed-off-by: Frank Blaschka <blaschka@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

qeth: bridgeport support - address notifications

Introduce functions to enable and disable bridgeport address
notification feature, sysfs attributes for access to these
functions from userspace, and udev events emitted when a host
joins or exits a bridgeport-enabled HiperSocket channel.

Signed-off-by: Eugene Crosser <eugene.crosser@ru.ibm.com>
Signed-off-by: Frank Blaschka <frank.blaschka@de.ibm.com>
Reviewed-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

qeth: bridgeport support - basic control

Introduce functions to assign roles and check state of bridgeport-capable
HiperSocket devices, and sysfs attributes providing access to these
functions from userspace. Introduce udev events emitted when the state
of a bridgeport device changes.

Signed-off-by: Eugene Crosser <eugene.crosser@ru.ibm.com>
Signed-off-by: Frank Blaschka <frank.blaschka@de.ibm.com>
Reviewed-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>