During IPL we register all chpids that are not in the unrecognized
state. This includes chpids that are not usable and chpids for which
the state could not be obtained.
Change that to only register chpids in the configured (usable) or
standby (usable after a configure operation) state. All other chpids
could only be made available by external control for which we would
receive machine checks.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Since commit 9f3d6d7 chsc_get_channel_measurement_chars is called with
interrupts disabled during resume from hibernate. Since this function
used spin_unlock_irq, interrupts have been enabled accidentally. Fix
this by using the irqsave variant.
Since we can't guarantee the IRQ-enablement state for all (future/
external) callers, change the locking in related functions to prevent
similar bugs in the future.
Fixes: 9f3d6d7 ("s390/cio: update measurement characteristics")
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
cio_cancel was declared twice. Remove one of them.
Signed-off-by: Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
During qdio_shutdown the queue tasklets are killed for all inbound and
outbound queues. The queue structures might be freed after
qdio_shutdown.
Thus it must be guaranteed that these queue tasklets are not rescheduled
after that. In addition the outbound queue timers are deleted and it
must
be guaranteed that these timers are not restarted after qdio_shutdown
processing. Timer deletion should make use of del_timer_sync() to make
sure qdio_outbound_timer() is finished on other CPUs as well. Queue
tasklets should be scheduled in state QDIO_IRQ_STATE_ACTIVE only.
Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Prior to starting IO qdio checks for the internal state of the ccw
device. These checks happen without locking, so consistency between
state evaluation and starting of the IO is not guaranteed.
Since the internal state is checked during ccw_device_start it is
safe to get rid of these additional checks.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
qdio sometimes checks return codes twice. First with the ccw device's
lock held and then a 2nd time after the lock is released. Simplify
the code by releasing the lock earlier and unify the return code
evaluation.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
All qdio functions that use spin_lock_irqsave are never used
from irq context. Thus it is safe to convert all of them to
use spin_lock_irq.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
A copy of struct subchannel_id is maintained in ccw_device_private.
The subchannel id is a property of the subchannel. The additional
copy is not needed.
Internal users can obtain it from subchannel.schid - device drivers
can use ccw_device_get_schid().
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
We want to get rid of the copy of struct subchannel_id maintained in
ccw_device_private, so obtain it using ccw_device_get_schid().
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
We want to get rid of the copy of struct subchannel_id maintained in
ccw_device_private, so obtain it from the subchannel directly.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
We store requests for channel path configure operations in an array but
maintain an additional cfg_busy variable (indicating if we have requests
stored in said array). When 2 tasks request a channel path configure
operation cfg_busy could be set to 0 even if we still have unprocessed
requests. This would lead to the second task being woken up although its
request was not processed yet.
Fix that by getting rid of cfg_busy and use the chp_cfg_task array
in the wake up condition.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
cfg_lock is never held long and we don't want to sleep while the
lock is being held. Thus it can be converted to a simple spinlock.
In addition we can now use the lock during the evaluation of a
wake_up condition.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The workqueue "chp_wq" is involved in performing pending
configure tasks for channel paths.
It has a single work item(&cfg_work) and hence doesn't require
ordering. Also, it is not being used on a memory reclaim path.
Hence, the singlethreaded workqueue has been replaced with the use of
system_wq.
System workqueues have been able to handle high level of concurrency
for a long time now and hence it's not required to have a singlethreaded
workqueue just to gain concurrency. Unlike a dedicated per-cpu workqueue
created with create_singlethread_workqueue(), system_wq allows multiple
work items to overlap executions even on the same CPU; however, a
per-cpu workqueue doesn't have any CPU locality or global ordering
guarantee unless the target CPU is explicitly specified and thus the
increase of local concurrency shouldn't make any difference.
Signed-off-by: Bhaktipriya Shridhar <bhaktipriya96@gmail.com>
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
When we fetch channel path descriptors via chsc we use a suboptimal
struct chsc_scpd and adjust that by casting the response to a generic
chsc_response_struct. Simplify the code by improving struct chsc_scpd.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
When fetching channel path descriptors we've only evaluated the rfmt
parameter which could lead us to trigger the chsc even though the
machine doesn't support the specific format or to not trigger the
chsc and report a failure to userspace even though the machine would've
supported it.
Improve these checks and change the parameters of the in-kernel
user to be less confusing.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Not all machines / hypervisors support the chsc commands to fetch
the fmt1 descriptor. When these commands fail the channel path would
currently not be available to linux.
Since users of these descriptors can already deal with invalid data
make fetching it optional. The only data that is mandatory for us is
the fmt0 channel path descriptor.
Also make the return code for missing facilities in
chsc_get_channel_measurement_chars consistent to other functions.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Via CHSC_INFO_CU we ought to provide userspace with control unit
configuration data. Due to an erroneous request code we trigger the
wrong chsc command. Fix this copy and paste error.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Fix an incorrect kernel doc comment in device_ops.c. Also
provide proper function markups while at it.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Prior to commit 1bc6664bdf a call to
enable_cmf for a device for which channel measurement was already
enabled resulted in a reset of the measurement data.
What looked like bugs at the time (a 2nd allocation was triggered
but failed, reset was called regardless of previous failures, and
errors have not been reported to userspace) was actually something
at least one userspace tool depended on. Restore that behavior in
a sane way.
Fixes: 1bc6664bdf ("s390/cio: use device_lock during cmb activation")
Cc: stable@vger.kernel.org #v4.4+
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Use only simple inline assemblies which consist of a single basic
block if the register asm construct is being used.
Otherwise gcc would generate broken code if the compiler option
--sanitize-coverage=trace-pc would be used.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Use only simple inline assemblies which consist of a single basic
block if the register asm construct is being used.
Otherwise gcc would generate broken code if the compiler option
--sanitize-coverage=trace-pc would be used.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The sync clock operation of the channel subsystem call for STP delivers
the TOD clock difference as a result. Use this TOD clock difference
instead of the difference between the TOD timestamps before and after
the sync clock operation.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Daniel van Gerpen <daniel@vangerpen.de>
Acked-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Convert the uses of pr_warning to pr_warn so there are fewer
uses of the old pr_warning.
Miscellanea:
o Align arguments
o Coalesce formats
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Per channel path measurement characteristics are obtained during channel
path registration. However if some properties of a channel path change
we don't update the measurement characteristics.
Make sure to update the characteristics when we change the properties of
a channel path or receive a notification from FW about such a change.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Make sure that in all cases where we could not obtain measurement
characteristics the associated fields are set to invalid values.
Note: without this change the "shared" capability of a channel path
for which we could not obtain the measurement characteristics was
incorrectly displayed as 0 (not shared). We will now correctly
report "unknown" in this case.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Measurement characteristics are allocated during channel path
registration but not freed during deregistration. Fix this by
embedding these characteristics inside struct channel_path.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Adding tracepoints to inline functions adds tracepoint invocation code
for each instance where the function is inlined. The resulting increase
in kernel code size can have negative impact:
- More cache misses in instruction cache
- Reduced amount of DMA-capable memory
Therefore change all functions implementing I/O instructions from inline
to normal functions.
Bloat-o-meter summary after change (using performance_defconfig):
add/remove: 24/2 grow/shrink: 4/39 up/down: 2205/-4858 (-2653)
Signed-off-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Add tracepoints to interrupt handler and core inline assemblies used by
the s390 common I/O layer. These tracepoints can be used to monitor and
validate hardware and hypervisor requests and responses.
Signed-off-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Reviewed-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Replace the current semi-arbitrary distribution of inline assemblies:
- Inline assemblies used by CIO go into ioasm.h
- Data definitions used by inline assemblies go into cio.h
Beyond cleaning up the current structure this is also required for
use of tracepoints in inline assemblies introduced by a follow-on
patch.
Signed-off-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Acked-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The numeric representation of the xsch instruction was incorrectly
specified, resulting in reserved fields of the instruction opcode
potentially being set to a non-zero value. While this doesn't currently
cause any problem, a future architecture might make use of these fields
so that the current specification could result in an exception or
unwanted side-effects.
Fix this by using the xsch instruction code for which support in
binutils was added in 2003.
Signed-off-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
There is no longer a need to maintain two versions of the same inline
assembly - one with exception handling, and one without - so get rid of
the duplicates and adjust names accordingly. This applies to stsch_err
and msch_err which are now renamed to stsch and msch respectively,
while the original msch function is removed.
Signed-off-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The debug_unregister() function performs also input parameter validation.
Thus the test around the calls is not needed.
This issue was detected by using the Coccinelle software.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
To collect the CPU registers of the crashed system allocated a single
page with memblock_alloc_base and use it as a copy buffer. Replace the
stop-and-store-status sigp with a store-status-at-address sigp in
smp_save_dump_cpus() and smp_store_status(). In both cases the target
CPU is already stopped and store-status-at-address avoids the detour
via the absolute zero page.
For kexec simplify s390_reset_system and call store_status() before
the prefix register of the boot CPU has been set to zero. Use STPX
to store the prefix register and remove dump_prefix_page.
Acked-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Allow to ipl from CCW based devices residing in any subchannel set.
Reviewed-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Simplify the css_generate_pgid code by using stap() independent of
CONFIG_SMP. For !CONFIG_SMP builds stap() will deliver the address
of the cpu we IPL'ed from (which can be != 0).
Note: the ifdef was likely added to be compatible with _very_ old
machines which we don't support anyway.
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>
Pull s390 updates from Martin Schwidefsky:
"There is only one new feature in this pull for the 4.4 merge window,
most of it is small enhancements, cleanup and bug fixes:
- Add the s390 backend for the software dirty bit tracking. This
adds two new pgtable functions pte_clear_soft_dirty and
pmd_clear_soft_dirty which is why there is a hit to
arch/x86/include/asm/pgtable.h in this pull request.
- A series of cleanup patches for the AP bus, this includes the
removal of the support for two outdated crypto cards (PCICC and
PCICA).
- The irq handling / signaling on buffer full in the runtime
instrumentation code is dropped.
- Some micro optimizations: remove unnecessary memory barriers for a
couple of functions: [smb_]rmb, [smb_]wmb, atomics, bitops, and for
spin_unlock. Use the builtin bswap if available and make
test_and_set_bit_lock more cache friendly.
- Statistics and a tracepoint for the diagnose calls to the
hypervisor.
- The CPU measurement facility support to sample KVM guests is
improved.
- The vector instructions are now always enabled for user space
processes if the hardware has the vector facility. This simplifies
the FPU handling code. The fpu-internal.h header is split into fpu
internals, api and types just like x86.
- Cleanup and improvements for the common I/O layer.
- Rework udelay to solve a problem with kprobe. udelay has busy loop
semantics but still uses an idle processor state for the wait"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (66 commits)
s390: remove runtime instrumentation interrupts
s390/cio: de-duplicate subchannel validation
s390/css: unneeded initialization in for_each_subchannel
s390/Kconfig: use builtin bswap
s390/dasd: fix disconnected device with valid path mask
s390/dasd: fix invalid PAV assignment after suspend/resume
s390/dasd: fix double free in dasd_eckd_read_conf
s390/kernel: fix ptrace peek/poke for floating point registers
s390/cio: move ccw_device_stlck functions
s390/cio: move ccw_device_call_handler
s390/topology: reduce per_cpu() invocations
s390/nmi: reduce size of percpu variable
s390/nmi: fix terminology
s390/nmi: remove casts
s390/nmi: remove pointless error strings
s390: don't store registers on disabled wait anymore
s390: get rid of __set_psw_mask()
s390/fpu: split fpu-internal.h into fpu internals, api, and type headers
s390/dasd: fix list_del corruption after lcu changes
s390/spinlock: remove unneeded serializations at unlock
...
cio_validate_io_subchannel() and cio_validate_msg_subchannel() are
identical, as the called functions already take care about the
differences between subchannel types.
Just inline the code into the only user,
cio_validate_subchannel(), instead.
Signed-off-by: Pierre Morel <pmorel@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Acked-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The ret variable is always set by the fn function.
There is no need to initialize it.
Signed-off-by: Pierre Morel <pmorel@linux.vnet.ibm.com>
Reviewed-By: Sascha Silbe <silbe@linux.vnet.ibm.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
device_ops.c should only contain functions that are called by ccw device
drivers. Move the cio internal functions that handle unconditional
reserve + release to device_pgid.c
Acked-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>
device_ops.c should only contain functions that are called by ccw device
drivers. Move the cio internal function ccw_device_call_handler to
device_fsm.c where it's used. Remove some useless comments while at it.
Acked-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>
Remove all the casts to and from the machine check interruption code.
This patch changes struct mci to a union, which contains an anonymous
structure with the already known bits and in addition an unsigned
long field, which contains the raw machine check interruption code.
This allows to simply assign and decoce the interruption code value
without the need for all those casts we had all the time.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
We often need to correlate an 8 bit path mask with the position
in a channel path array. Introduce and use pathmask_to_pos for
that task.
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>
During resume from hibernate we already reenable measurement block
updates on a per device basis. In addition to that we also need to
activate channel measurement globally using the set channel monitor
instruction.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Extended measurement blocks need to be 64 byte aligned. To achieve that
128 bytes for each measurement block are allocated and an align callback
returns a 64 byte aligned address inside this area.
Replace this code with kmem_cache allocations.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The measurement block for the extended measurement data is not freed when
switching off per device measurement. Free the measurement block after HW
stopped accessing it.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
During allocation of extended measurement blocks we check if the device is
already active for channel measurement and add the device to a list of
devices with active channel measurement. The check is done under ccwlock
protection and the list modification is guarded by a different lock.
To guarantee that both states are in sync make sure that both locks
are held during the allocation process (like it's already done for the
"normal" measurement block allocation).
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Devices with active channel measurement are included in a list. When a
device is removed without deactivating channel measurement first the
list_head is freed but still used. Fix this by making sure that
channel measurement is deactivated during device deregistration.
For devices that we deregister because they are no longer accessible
deactivating channel measurement will fail. In this case we can report
success because the FW will no longer access the measurement block.
In addition to these steps keep an extra device reference while
channel measurement is active.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Hold the device_lock during [de]activation of the channel measurement
block to synchronize concurrent usage of these functions.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Ensure that we hold the ccwlock when accessing private data. Return errors
that occur during measurement enabling to userspace. Apply some cleanups
while at it.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
