s390/monreader: Remove redundant NULL check before kfree

kfree on NULL pointer is a no-op.

Signed-off-by: Syam Sidhardhan <s.syam@samsung.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
s390/cio: collect format 1 channel-path description data

Collect format 1 channel-path description data for each CHPID
and update the information in one place.

Reviewed-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
s390/cio: make use of newly added format 1 channel-path data

Make use of the stored copy of format 1 channel-path data instead
of querying the information every time the corresponding function
is called.

Reviewed-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
s390/bpf,jit: use kcalloc instead of kmalloc and memset

Signed-off-by: Stelian Nirlu <steliannirlu@gmail.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
s390/dasd: remove cast for kzalloc return value

remove cast for kzalloc return value.

Signed-off-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
s390/cmm: Removed useless label

Rewrote conditional statement and eliminated the out_kthread label.

Signed-off-by: Alexandru Gheorghiu <gheorghiuandru@gmail.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
s390/hypfs: Use PTR_RET function

Used PTR_RET function instead of IS_ERR and PTR_ERR.
Patch found using coccinelle.

Signed-off-by: Alexandru Gheorghiu <gheorghiuandru@gmail.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
s390/dumpstack: fix call chain walking

dumpstack() did not always print a sane callchain when being called.
The reason is that show_trace() accessed register 15 directly to get
the current stack pointer and passed that pointer to __show_trace()
which expects a valid stack frame pointer as argument.
However due to tail call optimization the stack frame may not exist
anymore when __show_trace() gets called and therefore an invalid
stack frame pointer gets passed.
To prevent that disable tail call optimization for call chain walking
functions.
So move all the show_* functions to a dumpstack.c file like other
architectures have it already and add a -fno-optimize-sibling-calls
compile flag to both dumpstack.c and stacktrace.c to prevent tail
call optimization.

Fixes callchains that looked e.g. like this:

[   12.868258] Call Trace:
[   12.868262] ([<0000000000008000>] 0x8000)

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
s390/mm: speedup storage key initialization

Use sske with multiple block control to initialize storage keys within
a 1 MB frame at once.
It turned out that the sske with mb=1 is an order of magnitude faster
than pfmf. This is only an issue for very large systems (several 100GB)
where storage key initialization could last more than a minute.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
s390/bitops: remove unnecessary macro definitions in asm/bitops.h

Remove unused __BITOPS_ALIGN, and replace __BITOPS_WORDSIZE with
BITS_PER_LONG.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
s390/cio: Use BITS_TO_LONGS() instead of __BITOPS_WORDS()

Use BITS_TO_LONGS() instead of __BITOPS_WORDS() that is considered
to be private macro in asm/bitops.h for s390.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
s390/bitops: get rid of __BITOPS_BARRIER()

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
s390/hibernate: Save and restore absolute zero pages

Since commit 5f954c34 ([S390] hibernation: fix lowcore handling)
the absolute zero lowcore is lost during suspend/resume.
For example, this leads to the problem that the re-IPL device
for kdump is no longer set after resume.

With this patch during suspend a buffer is allocated in the new PM
notifier "suspend_pm_cb" and then the absolute zero lowcore is saved
to that buffer. The resume code then copies back this buffer to
absolute zero and afterwards the PM notifier releases the memory.

Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
s390/cio: wait_cons_dev don't use static variable

wait_cons_dev is used to busy wait for an interrupt on the console
ccw device. Stop using the static console_subchannel and add a
parameter to this function to specify on which ccw device/subchannel
we have to do the polling.

While at it rename the function to ccw_device_wait_idle and
move it to device.c

Reviewed-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
s390/cio: ccw_device_force_console don't use static variable

force_console is used to wake up the CCW based console device to
print a panic message in case something goes wrong in a suspend
or resume cycle. Stop using the static console_subchannel and add
a parameter to this function to specify which ccw device we have
to wake up.

Reviewed-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
s390/cio: split subchannel registration

Split the subchannel registration in device_initialize and device_add
and move the initialization part inside the allocation function. With
this change we can use refcounting during the complete lifespan of a
subchannel which is important for devices where we do the actually
registration at a later time.

Reviewed-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
s390/cio: get rid of static console subchannel

Remove the static console subchannel (and friends) and use dynamic
allocation for these structures. With this change the console
subchanel is treated (mostly) like any other subchannel and we can
remove some special cases.

Reviewed-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
s390/cio: get rid of static console device

Remove the static console ccw device (and friends) and use dynamic
allocation for these structures. With this change the console
device is treated (mostly) like any other ccw device and we can
remove some special cases.

Reviewed-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
s390/css: introduce cio_register_early_subchannels

Use cio_register_early_subchannels to register early subchannels
which are already in use. Call this function before we do the
actual subchannel scanning loop. This helps us to get rid of some
more special cases regarding the console subchannel.

Reviewed-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
s390/css: remove unused function definitions

Make css_probe_device static and remove an unimplemented prototype.

Reviewed-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>