The dasd device driver selects which (alias or base) device is used
for a given requests when the request is build. If the chosen alias
device is set offline before the request gets queued to the device
queue the starting function may use device structures that are
already freed. This might lead to a hanging offline process or a
kernel panic.

Add a check to the starting function that returns the request to the
upper layer if the device is already in offline processing.

In addition to that prevent that an alias device that's already in
offline processing gets chosen as start device.
Reviewed-by: NSebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: NPeter Oberparleiter <peter.oberparleiter@linux.vnet.ibm.com>
Signed-off-by: NStefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

This more accurately reflects what these drivers actually do.
Suggested-by: NPaolo Bonzini <pbonzini@redhat.com>
Acked-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>

Eric noticed problems with vhost-scsi and virtio-ccw: vhost-scsi
complained about overwriting values in the config space, which
was triggered by a broken implementation of virtio-ccw's config
get/set routines. It was probably sheer luck that we did not hit
this before.

When writing a value to the config space, the WRITE_CONF ccw will
always write from the beginning of the config space up to and
including the value to be set. If the config space up to the value
has not yet been retrieved from the device, however, we'll end up
overwriting values. Keep track of the known config space and update
if needed to avoid this.

Moreover, READ_CONF will only read the number of bytes it has been
instructed to retrieve, so we must not copy more than that to the
buffer, or we might overwrite trailing values.
Reported-by: NEric Farman <farman@linux.vnet.ibm.com>
Signed-off-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: NEric Farman <farman@linux.vnet.ibm.com>
Tested-by: NEric Farman <farman@linux.vnet.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Cc: stable@vger.kernel.org
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Fix this error when compiling with CONFIG_SMP=n and
CONFIG_DYNAMIC_DEBUG=y:

drivers/s390/char/sclp_early.c: In function 'sclp_read_info_early':
drivers/s390/char/sclp_early.c:87:19: error: 'EBUSY' undeclared (first use in this function)
   } while (rc == -EBUSY);
                   ^
Signed-off-by: NSebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Set the 'quality' property in the zcrypt rng device structure to enable the
zcrypt hwrng device to take part in the kernel entropy seeding process.
A module parameter named hwrng_seed will be introduced to disable the
participation. By default this parameter is set to 1 (enabled).
Signed-off-by: NIngo Tuchscherer <ingo.tuchscherer@de.ibm.com>
Signed-off-by: NHarald Freudenberger <freude@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

It turned out that SIGP set-multi-threading can only be done once.
Therefore switching to a different MT level after switching to
sclp.mtid_prev in the dump case fails.

As a symptom specifying the "nosmt" parameter currently fails for
the kdump kernel and the kernel starts with multi-threading enabled.

So fix this and issue diag 308 subcode 1 call after collecting the
CPU states for the dump. Also enhance the diag308_reset() function to
be usable also with enabled lowcore protection and prefix register != 0.
After the reset it is possible to switch the MT level again. We have
to do the reset very early in order not to kill the already initialized
console. Therefore instead of kmalloc() the corresponding memblock
functions have to be used. To avoid copying the sclp cpu code into
sclp_early, we now use the simple sigp loop method for CPU detection.
Signed-off-by: NMichael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The SCLP interface to query, configure and deconfigure CPUs actually
operates on cores. For a machine without the multi-threading faciltiy
a CPU and a core are equivalent but starting with System z13 a core
can have multiple hardware threads, also referred to as logical CPUs.

To avoid confusion replace the word 'cpu' with 'core' in the SCLP
interface. Also replace MAX_CPU_ADDRESS with SCLP_MAX_CORES.
The core-id is an 8-bit field, the maximum thread id is in the range
0-31. The theoretical limit for the CPU address is therefore 8191.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

In case of request timeouts an AP queue reset will be triggered to
recover and reinitialize the AP queue. The previous behavior was an
immediate reset execution regardless of current/pending requests.
Due to newly changed firmware behavior the reset may be delayed, based
on the priority of pending request. The device driver's waiting time
frame was limited, hence it did not received the reset response. As a
consequence interrupts would not be enabled afterwards.

The RAPQ (queue reset) and AQIC (interrupt control) commands will be
treated fully asynchronous now. The device driver will check the reset and
interrupt states periodically, thus it can handle the reinitialization
properly.
Signed-off-by: NIngo Tuchscherer <ingo.tuchscherer@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

__constant_cpu_to_le16 converted to cpu_to_le16
Signed-off-by: NVaishali Thakkar <vthakkar1994@gmail.com>
Signed-off-by: NIngo Tuchscherer <ingo.tuchscherer@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

strnlen_user() returns the length of the string including terminating 0.
So avoid counting it again and unnecessarily reducing maximum string
size by 1.
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

schedule_timeout takes a timeout in jiffies but the code currently is
passing in a constant SDIAS_SLEEP_TICKS, as this is otherwise unused
it is replaced by 500ms as recommended by Michael Holzheu
<holzheu@linux.vnet.ibm.com> and converted with msecs_to_jiffies();
As SDIAS_SLEEP_TICKS was only used in this one location it is dropped.

Patch was compile tested with (s390) defconfig +
CONFIG_MARCH_Z10=y, (implies CONFIG_CRASH_DUMP=y)

Patch is against 4.1-rc5 (localversion-next is -next-20150529)

Link: http://lkml.org/lkml/2015/5/29/235Signed-off-by: NNicholas Mc Guire <hofrat@osadl.org>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Use the generic mechanism to declare a bitmap instead of unsigned long.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

'0' is now used as the default cmd_per_lun value,
so there's no need to explicitly set it to '1' in the
host template.
Signed-off-by: NHannes Reinecke <hare@suse.de>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJames Bottomley <JBottomley@Odin.com>

With the mutex_trylock bit gone from blkdev_reread_part(), the retry logic
in dasd_scan_partitions() shouldn't be necessary.

CC: Christoph Hellwig <hch@infradead.org>
CC: Jens Axboe <axboe@kernel.dk>
CC: Tejun Heo <tj@kernel.org>
CC: Alexander Viro <viro@zeniv.linux.org.uk>
CC: Markus Pargmann <mpa@pengutronix.de>
CC: Stefan Weinhuber <wein@de.ibm.com>
CC: Stefan Haberland <stefan.haberland@de.ibm.com>
CC: Sebastian Ott <sebott@linux.vnet.ibm.com>
CC: Fabian Frederick <fabf@skynet.be>
CC: Ming Lei <ming.lei@canonical.com>
CC: David Herrmann <dh.herrmann@gmail.com>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Peter Zijlstra <peterz@infradead.org>
CC: nbd-general@lists.sourceforge.net
CC: linux-s390@vger.kernel.org
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Acked-by: NSebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: NMing Lei <ming.lei@canonical.com>
Signed-off-by: NJarod Wilson <jarod@redhat.com>
Signed-off-by: NJens Axboe <axboe@fb.com>

Also remove the obsolete comment.
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Tested-by: NJarod Wilson <jarod@redhat.com>
Acked-by: NJarod Wilson <jarod@redhat.com>
Acked-by: NSebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: NMing Lei <ming.lei@canonical.com>
Signed-off-by: NJens Axboe <axboe@fb.com>

An attempt to configure a CTC device as LCS results in the
following error message:

  (null): Detecting a network adapter for LCS devices failed
          with rc=-5 (0xfffffffb)

"(null)" results from access to &card->dev->dev in lcs_new_device()
which is only initialized later in the function. Fix this by using
&ccwgdev->dev instead which is initialized before lcs_new_device()
is called.
Signed-off-by: NPeter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: NUrsula Braun <ursula.braun@de.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since recently, `checkpatch.pl` advices that ENOSYS should not be
used for anything other than "invalid syscall nr". This patch
replaces ENOSYS return code with EOPNOTSUPP for the "unsupported
function" conditions.
Signed-off-by: NEugene Crosser <Eugene.Crosser@ru.ibm.com>
Signed-off-by: NUrsula Braun <ursula.braun@de.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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: NThomas Richter <tmricht@linux.vnet.ibm.com>
Signed-off-by: NEugene Crosser <Eugene.Crosser@ru.ibm.com>
Signed-off-by: NUrsula Braun <ursula.braun@de.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

OSA Ethernet hardware is introducing BRIDGEPORT functionality
similar (but not identical) to HiperSockets BRIDGEPORT. This
patch makes HiperSockets BRIDGEPORT related sysfs attributes
and udev events work with OSA hardware too.
Reviewed-by: NThomas Richter <tmricht@linux.vnet.ibm.com>
Signed-off-by: NEugene Crosser <Eugene.Crosser@ru.ibm.com>
Signed-off-by: NUrsula Braun <ursula.braun@de.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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: NThomas Richter <tmricht@linux.vnet.ibm.com>
Signed-off-by: NEugene Crosser <Eugene.Crosser@ru.ibm.com>
Signed-off-by: NUrsula Braun <ursula.braun@de.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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

Function that executes IPA commands returns the result code from the
IPA response block. If non-negative, it needs to be transformed into
errno-compatible code before returning to the caller.
Signed-off-by: NEugene Crosser <Eugene.Crosser@ru.ibm.com>
Signed-off-by: NUrsula Braun <ursula.braun@de.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

ethtool is used to change some device driver features
such as RX/TX hardware checksum offloading.
The qeth device driver callback function to
turn on/off RX hardware check sum handling never changes
the hardware configuration.
The NETIF_F_RXCSUM bit is cleared when the feature bitset
type netdev_features_t(64bit) is assigned to 32 a bit
variable.

This patch fixes the NETIF_F_RXCSUM handling.
Also there is no need to manipulate the device's features
bit set as this is done by the caller when no error occurs.
Signed-off-by: NThomas Richter <tmricht@linux.vnet.ibm.com>
Signed-off-by: NUrsula Braun <ursula.braun@de.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Enabling a DASD that was configured to use the DIAG250 access method
while the corresponding kernel module dasd_diag_mod has not been loaded
fails with an error message. To fix this, users need to manually load
the dasd_diag_mod module.

This procedure can be simplified by automatically loading the
dasd_diag_mod from within the kernel when a DASD configured for DIAG250
is set online.
Signed-off-by: NPeter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Let's also move the facilities into the sclp struct, so we can avoid
another separate external variable.
Acked-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NDavid Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

As all relevant sclp data is now directly accessible, let's move the
logic of these two functions to the single caller.
Acked-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NDavid Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Let's unify basic access to sclp fields by storing the data in an external
struct in asm/sclp.h.

The values can now directly be accessed by other components, so there is
no need for most accessor functions and external variables anymore.

The mtid, mtid_max and facility part will be cleaned up separately.
Acked-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NDavid Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Added domain checking to prevent reset failures caused by invalid
domains.
Corrected removal sequence of bus attributes and device.
Reviewed-by: NHarald Freudenberger <freude@linux.vnet.ibm.com>
Signed-off-by: NIngo Tuchscherer <ingo.tuchscherer@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The ap poll timer restart condition was wrong. Hence the poll timer
was not restarted reliable when setting a new time interval via the
poll_timeout sysfs attribute.
Added missing timer locking.
Reported-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NIngo Tuchscherer <ingo.tuchscherer@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

If one memory allocation fails, there is a memory leak.
Signed-off-by: NChristophe Jaillet <christophe.jaillet@wanadoo.fr>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The seq_printf return value, because it's frequently misused,
will eventually be converted to void.

See: commit 1f33c41c ("seq_file: Rename seq_overflow() to
     seq_has_overflowed() and make public")
Signed-off-by: NJoe Perches <joe@perches.com>
Acked-by: NSebastian Ott <sebott@linux.vnet.ibm.com>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The DASD device driver prevents I/O from being started on stopped
devices. This also prevented channel paths to be verified and so
the device was unable to be resumed.
Fix by allowing path verification requests on stopped devices.
Signed-off-by: NStefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The DASD device driver only has a limited amount of memory to build
I/O requests.
This memory was used by blocklayer requests leading to an inability
to build needed internal requests to resume the device.
Fix by preventing the DASD driver to fetch requests for a stopped
device.
Signed-off-by: NStefan Haberland <stefan.haberland@de.ibm.com>
Reference-ID: RQM 2520
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Fix ref counting for DASD devices leading to an inability to set a
DASD device offline.
Before a worker is scheduled the DASD device driver takes a reference
to the device. If the worker was already scheduled this reference was
never freed.
Fix by giving the reference to the DASD device free when
schedule_work() returns false.
Signed-off-by: NStefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Commit 27356f54 ("mm/hotplug: verify hotplug memory range")
introduced a check that makes add_memory() only accept section size
aligned memory.

Therefore on z/VM systems, where standby memory is not aligned, no
standby memory is registered at all.

Example:

 #cp def store 3504M standby 2336M
 00: CP Q V STORE
 00: STORAGE = 3504M MAX = 6G INC = 8M STANDBY = 2336M RESERVED = 0

For this setup the following error message is printed:

 Section-unaligned hotplug range: start 0xdb000000, size 0x92000000

So fix this and register aligned memory in "sclp_cmd.c". This means
that for the corner cases where the standby memory is not aligned we
loose some memory.

In order to inform the user about the potential loss of standby memory,
we add a new message for each added standby block and print how
much of the standby memory is usable, for example:

 sclp_cmd.4336b4: Standby memory at 0x50000000 (256M of 256M usable)
 sclp_cmd.4336b4: Standby memory at 0xb0000000 (256M of 256M usable)
 sclp_cmd.4336b4: Standby memory at 0xdb000000 (2048M of 2336M usable)

We also ensure that a potential memory block that contains both "assigned"
and "standby" memory cannot be setup offline.
Reviewed-by: NGerald Schaefer <gerald.schaefer@de.ibm.com>
Reviewed-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMichael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

As of last patch, virtio_device_is_legacy_only is always false,
drop the test from virtio ccw.
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
Reviewed-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (slight reword)

Allocating a large number of elements in atomic context could quickly
deplete memory reserves, so just disallow atomic resizing entirely.

Nothing currently uses mempool_resize() with anything other than
GFP_KERNEL, so convert existing callers to drop the gfp_mask.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: NDavid Rientjes <rientjes@google.com>
Acked-by: Steffen Maier <maier@linux.vnet.ibm.com>	[zfcp]
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Steve French <sfrench@samba.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Remove the hard coded scheduler for the DASD device driver to enable
change of the scheduler during runtime. Set recommended deadline
scheduler via additional udev rule.
Signed-off-by: NStefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Given that the kernel now always runs in 64 bit mode, it is
pointless to check if the z/Architecture mode is active.
Remove the checks.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Remove the 31 bit support in order to reduce maintenance cost and
effectively remove dead code. Since a couple of years there is no
distribution left that comes with a 31 bit kernel.

The 31 bit kernel also has been broken since more than a year before
anybody noticed. In addition I added a removal warning to the kernel
shown at ipl for 5 minutes: a960062e ("s390: add 31 bit warning
message") which let everybody know about the plan to remove 31 bit
code. We didn't get any response.

Given that the last 31 bit only machine was introduced in 1999 let's
remove the code.
Anybody with 31 bit user space code can still use the compat mode.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>