When do_qdio() returns with an unexpected error, qeth_flush_buffers()
kicks off a recovery action.

In such a case there's no point in starting TX completion processing,
the device gets torn down anyway. So take a closer look at do_qdio()'s
return value, and skip the TX completion processing accordingly.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Acked-by: NWillem de Bruijn <willemb@google.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

As part of the TX queue selection for af_iucv skbs,
qeth_l3_get_cast_type_rcu() ends up calling qeth_get_ether_cast_type().
Which is rather fragile, since such skbs don't have a proper ETH header
and we rely on it being zeroed out in the right places. Add a separate
case for ETH_P_AF_IUCV instead that does the right thing.

When later building the HW header for such skbs, don't hard-code the
cast type but follow the same path as for other protocol types. Here
the cast type should naturally come from the skb's queue mapping.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Acked-by: NWillem de Bruijn <willemb@google.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

qeth_l3_hard_start_xmit() already determined the skb's proto. Avoid
doing so a second time when it calls qeth_l3_get_cast_type().
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Acked-by: NWillem de Bruijn <willemb@google.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

Replace our home-grown helper with the more robust vlan_get_protocol().
This is pretty much a 1:1 replacement, we just need to pass around a
proper ETH_P_* everyhwere and convert the old value range.

For readability also convert the protocol checks in
qeth_l3_hard_start_xmit() to a switch statement.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Acked-by: NWillem de Bruijn <willemb@google.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

We have two usage patterns:
1. get & ->setup() a new discipline, or
2. ->remove() & put the currently loaded one.

Add corresponding helpers that hide the internals & error handling.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: NAlexandra Winter <wintera@linux.ibm.com>
Acked-by: NWillem de Bruijn <willemb@google.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

ip_finish_output_gso() may call .ndo_features_check() even before the
skb has a L2 header. This conflicts with qeth_get_ip_version()'s attempt
to inspect the L2 header via vlan_eth_hdr().

Switch to vlan_get_protocol(), as already used further down in the
common qeth_features_check() path.

Fixes: f13ade19 ("s390/qeth: run non-offload L3 traffic over common xmit path")
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

Due to insufficient locking, qeth_core_set_online() and
qeth_dev_layer2_store() can run in parallel, both attempting to load &
setup the discipline (and stepping on each other toes along the way).
A similar race can also occur between qeth_core_remove_device() and
qeth_dev_layer2_store().

Access to .discipline is meant to be protected by the discipline_mutex,
so add/expand the locking in qeth_core_remove_device() and
qeth_core_set_online().
Adjust the locking in qeth_l*_remove_device() accordingly, as it's now
handled by the callers in a consistent manner.

Based on an initial patch by Ursula Braun.

Fixes: 9dc48ccc ("qeth: serialize sysfs-triggered device configurations")
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: NAlexandra Winter <wintera@linux.ibm.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

When qeth_dev_layer2_store() - holding the discipline_mutex - waits
inside qeth_l*_remove_device() for a qeth_do_reset() thread to complete,
we can hit a deadlock if qeth_do_reset() concurrently calls
qeth_set_online() and thus tries to aquire the discipline_mutex.

Move the discipline_mutex locking outside of qeth_set_online() and
qeth_set_offline(), and turn the discipline into a parameter so that
callers understand the dependency.

To fix the deadlock, we can now relax the locking:
As already established, qeth_l*_remove_device() waits for
qeth_do_reset() to complete. So qeth_do_reset() itself is under no risk
of having card->discipline ripped out while it's running, and thus
doesn't need to take the discipline_mutex.

Fixes: 9dc48ccc ("qeth: serialize sysfs-triggered device configurations")
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: NAlexandra Winter <wintera@linux.ibm.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

In dasd_alias_disconnect_device_from_lcu the device is removed from any
list on the LCU. Afterwards the LCU is removed from the lcu list if it
does not contain devices any longer.

The lcu->lock protects the lcu from parallel updates. But to cancel all
workers and wait for completion the lcu->lock has to be unlocked.

If two devices are removed in parallel and both are removed from the LCU
the first device that takes the lcu->lock again will delete the LCU because
it is already empty but the second device also tries to free the LCU which
leads to a list corruption of the lcu list.

Fix by removing the device right before the lcu is checked without
unlocking the lcu->lock in between.

Fixes: 8e09f215 ("[S390] dasd: add hyper PAV support to DASD device driver, part 1")
Cc: stable@vger.kernel.org
Signed-off-by: NStefan Haberland <sth@linux.ibm.com>
Reviewed-by: NJan Hoeppner <hoeppner@linux.ibm.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

dasd_alias_add_device() moves devices to the active_devices list in case
of a scheduled LCU update regardless if they have previously been in a
pavgroup or not.

Example: device A and B are in the same pavgroup.

Device A has already been in a pavgroup and the private->pavgroup pointer
is set and points to a valid pavgroup. While going through dasd_add_device
it is moved from the pavgroup to the active_devices list.

In parallel device B might be removed from the same pavgroup in
remove_device_from_lcu() which in turn checks if the group is empty
and deletes it accordingly because device A has already been removed from
there.

When now device A enters remove_device_from_lcu() it is tried to remove it
from the pavgroup again because the pavgroup pointer is still set and again
the empty group will be cleaned up which leads to a list corruption.

Fix by setting private->pavgroup to NULL in dasd_add_device.

If the device has been the last device on the pavgroup an empty pavgroup
remains but this will be cleaned up by the scheduled lcu_update which
iterates over all existing pavgroups.

Fixes: 8e09f215 ("[S390] dasd: add hyper PAV support to DASD device driver, part 1")
Cc: stable@vger.kernel.org
Signed-off-by: NStefan Haberland <sth@linux.ibm.com>
Reviewed-by: NJan Hoeppner <hoeppner@linux.ibm.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Prevent _lcu_update from adding a device to a pavgroup if the LCU still
requires an update. The data is not reliable any longer and in parallel
devices might have been moved on the lists already.
This might lead to list corruptions or invalid PAV grouping.
Only add devices to a pavgroup if the LCU is up to date. Additional steps
are taken by the scheduled lcu update.

Fixes: 8e09f215 ("[S390] dasd: add hyper PAV support to DASD device driver, part 1")
Cc: stable@vger.kernel.org
Signed-off-by: NStefan Haberland <sth@linux.ibm.com>
Reviewed-by: NJan Hoeppner <hoeppner@linux.ibm.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

For an LCU update a read unit address configuration IO is required.
This is started using sleep_on(), which has early exit paths in case the
device is not usable for IO. For example when it is in offline processing.

In those cases the LCU update should fail and not be retried.
Therefore lcu_update_work checks if EOPNOTSUPP is returned or not.

Commit 41995342 ("s390/dasd: fix endless loop after read unit address configuration")
accidentally removed the EOPNOTSUPP return code from
read_unit_address_configuration(), which in turn might lead to an endless
loop of the LCU update in offline processing.

Fix by returning EOPNOTSUPP again if the device is not able to perform the
request.

Fixes: 41995342 ("s390/dasd: fix endless loop after read unit address configuration")
Cc: stable@vger.kernel.org #5.3
Signed-off-by: NStefan Haberland <sth@linux.ibm.com>
Reviewed-by: NJan Hoeppner <hoeppner@linux.ibm.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Replace a comma between expression statements by a semicolon.
Signed-off-by: NZheng Yongjun <zhengyongjun3@huawei.com>
Signed-off-by: NHarald Freudenberger <freude@linux.ibm.com>
Signed-off-by: NHeiko Carstens <hca@linux.ibm.com>

udelay_simple() callers can make use of the now simplified udelay()
implementation. No need to keep it.
Signed-off-by: NHeiko Carstens <hca@linux.ibm.com>

Use of sch->dev reference after the put_device() call could trigger
the use-after-free bugs.

Fix this by simply adjusting the position of put_device.

Fixes: 37db8985 ("s390/cio: add basic protected virtualization support")
Reported-by: NHulk Robot <hulkci@huawei.com>
Suggested-by: NCornelia Huck <cohuck@redhat.com>
Signed-off-by: NQinglang Miao <miaoqinglang@huawei.com>
Reviewed-by: NCornelia Huck <cohuck@redhat.com>
Reviewed-by: NVineeth Vijayan <vneethv@linux.ibm.com>
[vneethv@linux.ibm.com: Slight modification in the commit-message]
Signed-off-by: NVineeth Vijayan <vneethv@linux.ibm.com>
Signed-off-by: NHeiko Carstens <hca@linux.ibm.com>

When qeth_qdio_handle_aob() frees dangling allocations in the notified
TX buffer, there are rare tear-down cases where
qeth_drain_output_queue() would later call qeth_clear_output_buffer()
for the same buffer - and thus end up walking the buffer a second time
to check for dangling kmem_cache allocations.

Luckily current code previously scrubs such a buffer, so
qeth_clear_output_buffer() would find buf->buffer->element[i].addr as
NULL and not do anything. But this is fragile, and we can easily improve
it by consistently clearing the ->is_header flag after freeing the
allocation.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Reuse the QETH_QDIO_BUF_EMPTY state to indicate that a TX buffer has
been completed with a QAOB notification, and may be cleaned up by
qeth_cleanup_handled_pending().
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

For TX buffers that require an additional async notification via QAOB, the
TX completion code can now manage all the necessary processing if the
notification has already occurred (or is occurring concurrently).

In such cases we can avoid replacing the metadata that is associated
with the buffer's slot on the ring, and just keep using the current one.

As qeth_clear_output_buffer() will also handle any kmem cache-allocated
memory that was mapped into the TX buffer, qeth_qdio_handle_aob()
doesn't need to worry about it.

While at it, also remove the unneeded forward declaration for
qeth_init_qdio_out_buf().
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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

Bus drivers have their own way of describing the sysfs attributes that
all devices on a bus should provide.
Switch ccwgroup_attr_groups over to use bus->dev_groups, and thus
free up dev->groups for usage by the ccwgroup device drivers.

While adjusting the attribute naming, use ATTRIBUTE_GROUPS() to get rid
of some boilerplate code.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Acked-by: NHeiko Carstens <hca@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

INIT_LIST_HEAD() only needs to be called on actual list heads.
While at it clarify the naming of the field.
Suggested-by: NVasily Gorbik <gor@linux.ibm.com>
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The request_queue can trivially be derived from the request.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDamien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Reviewed-by: NChaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Acked-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

The device is being unplugged, so pass the request to userspace to
ask for a graceful cleanup. This should free up the thread that
would otherwise loop waiting for the device to be fully released.
Signed-off-by: NEric Farman <farman@linux.ibm.com>
Reviewed-by: NCornelia Huck <cohuck@redhat.com>
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>

As part of removing broken pm-support from s390 arch, remove
the pm callbacks from ccw-bus driver.The power-management functions
are unused since the 'commit 39421627 ("s390: remove broken
hibernate / power management support")'.
Signed-off-by: NVineeth Vijayan <vneethv@linux.ibm.com>
Reviewed-by: NPeter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: NHeiko Carstens <hca@linux.ibm.com>

The power-management functions are unused since the
'commit 39421627 ("s390: remove broken hibernate / power
management support")'. Remove the unused pm callbacks from
css-bus driver.
Signed-off-by: NVineeth Vijayan <vneethv@linux.ibm.com>
Reviewed-by: NPeter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: NHeiko Carstens <hca@linux.ibm.com>

The power-management functions are unused since the
'commit 39421627 ("s390: remove broken hibernate / power
management support")'. Remove these unused pm callbacks from
io-subchannel drivers.
Signed-off-by: NVineeth Vijayan <vneethv@linux.ibm.com>
Reviewed-by: NPeter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: NHeiko Carstens <hca@linux.ibm.com>

As part of removing the broken pm-support from s390 arch, remove
the pm-calls from chsc subchannel driver. The power-management
functions are unused since the 'commit 39421627 ("s390: remove
broken hibernate / power management support")'.
Signed-off-by: NVineeth Vijayan <vneethv@linux.ibm.com>
Reviewed-by: NPeter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: NHeiko Carstens <hca@linux.ibm.com>

The Power-management related functions are unused since
'commit 39421627 ("s390: remove broken hibernate / power management
support")'. Remove them from the unit-record device driver.
Signed-off-by: NVineeth Vijayan <vneethv@linux.ibm.com>
Signed-off-by: NHeiko Carstens <hca@linux.ibm.com>

The power-management related functions are unused since
'commit 39421627 ("s390: remove broken hibernate / power
management support")'. Remove them from tape drivers.
Signed-off-by: NVineeth Vijayan <vneethv@linux.ibm.com>
Reviewed-by: NJan Höppner <hoeppner@linux.ibm.com>
Signed-off-by: NHeiko Carstens <hca@linux.ibm.com>

The 'commit 39421627 ("s390: remove broken hibernate /
power management support")' removes the pm-support. Remove the
unused functions in eadm-sch drivers.
Signed-off-by: NVineeth Vijayan <vneethv@linux.ibm.com>
Reviewed-by: NPeter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: NHeiko Carstens <hca@linux.ibm.com>

The power-management functions are unused since the
'commit 39421627 ("s390: remove broken hibernate / power management
support")'. Remove the unsued pm functions from the console drivers.
Signed-off-by: NVineeth Vijayan <vneethv@linux.ibm.com>
Signed-off-by: NHeiko Carstens <hca@linux.ibm.com>

The power-management related functions are unused since the
'commit 39421627 ("s390: remove broken hibernate / power management
support")'. Remove them from dasd drivers.
Signed-off-by: NVineeth Vijayan <vneethv@linux.ibm.com>
Reviewed-by: NStefan Haberland <sth@linux.ibm.com>
Signed-off-by: NHeiko Carstens <hca@linux.ibm.com>

As part of removing the power management support from
s390 arch, remove PM callbacks from the scsi/zfcp driver.
Signed-off-by: NVineeth Vijayan <vneethv@linux.ibm.com>
Reviewed-by: NSteffen Maier <maier@linux.ibm.com>
Signed-off-by: NHeiko Carstens <hca@linux.ibm.com>

gfp_type() uses in_interrupt() to figure out the correct GFP mask.

The usage of in_interrupt() in drivers is phased out and Linus clearly
requested that code which changes behaviour depending on context should
either be separated or the context be conveyed in an argument passed by the
caller, which usually knows the context.

ctcmpc_tx() is used as net_device_ops::ndo_start_xmit. This callback is
invoked with disabled bottom halves.

Use GFP_ATOMIC for memory allocation in ctcmpc_tx().
Remove gfp_type() since the last user is gone.
Reviewed-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

gfp_type() uses in_interrupt() to figure out the correct GFP mask.

The usage of in_interrupt() in drivers is phased out and Linus clearly
requested that code which changes behaviour depending on context should
either be separated or the context be conveyed in an argument passed by the
caller, which usually knows the context.

The memory allocation of `ch' a few lines above is using GFP_KERNEL,
also an allocation a few lines later is using GFP_KERNEL.

Use GFP_KERNEL for the memory allocation.
Reviewed-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

gfp_type() uses in_interrupt() to figure out the correct GFP mask.

The usage of in_interrupt() in drivers is phased out and Linus clearly
requested that code which changes behaviour depending on context should
either be separated or the context be conveyed in an argument passed by the
caller, which usually knows the context.

The call chain of ctcmpc_unpack_skb():
ctcmpc_bh()
 -> ctcmpc_unpack_skb()

ctcmpc_bh() is a tasklet handler so GFP_ATOMIC is needed.

Use GFP_ATOMIC as allocation type in ctcmpc_unpack_skb().
Reviewed-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

The size of struct pdu is 8 byte. The memory is allocated, initialized,
used and deallocated a few lines later.

It is more efficient to avoid the allocation/free dance and assign the
values directly to skb's data part instead of using memcpy() for it.

Avoid an allocation of struct pdu and use the resulting skb pointer
instead.
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
[jwi: Fix-up the pdu_offset, adjust skb->len for the pushed length.
      Reflow the commit msg.]
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

The size of struct qllc is 2 byte. The memory for is allocated,
initialized, used and deallocated a few lines later.

It is more efficient to avoid the allocation/free dance and assign the
values directly to skb's data part instead of using memcpy() for it.

Avoid an allocation of struct qllc and use the resulting skb pointer
instead.
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
[jwi: remove a newline, reflow the commit msg]
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

The size of struct th_header is 8 byte and the size of struct th_sweep
is 16 byte. The memory for is allocated, initialized, used and
deallocated a few lines later.

It is more efficient to avoid the allocation/free dance and assign the
values directly to skb's data part instead of using memcpy() for it.

Avoid an allocation of struct th_sweep/th_header and use the resulting
skb pointer instead.
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
[jwi: use skb_put_zero(), instead of skb_put() + memset to 0]
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

We can just dereference the point in struct gendisk instead.  Also
remove the now unused export.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJan Kara <jack@suse.cz>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>