Commit Graph

810 Commits

Author SHA1 Message Date
Sebastian Ott 4475aeb8b7 s390/cio: fix premature wakeup during chp configure
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>
2016-07-31 05:27:57 -04:00
Sebastian Ott 837c522055 s390/cio: convert cfg_lock mutex to spinlock
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>
2016-07-31 05:27:57 -04:00
Bhaktipriya Shridhar 7b1058bc59 s390/cio/chp : Remove deprecated create_singlethread_workqueue
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>
2016-07-18 10:17:21 +02:00
Sebastian Ott 687cb7f216 s390/chsc: improve channel path descriptor determination
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>
2016-07-15 14:32:01 +02:00
Sebastian Ott f9773768f1 s390/chsc: sanitize fmt check for chp_desc determination
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>
2016-07-15 14:32:00 +02:00
Sebastian Ott 0b60137377 s390/cio: make fmt1 channel path descriptor optional
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>
2016-07-15 14:31:59 +02:00
Sebastian Ott 6228c2a51e s390/chsc: fix ioctl CHSC_INFO_CU command
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>
2016-07-15 14:31:58 +02:00
Sebastian Ott 388b74d3a9 s390/cio/device_ops: fix kernel doc
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>
2016-07-15 14:31:57 +02:00
Sebastian Ott 0f5d050cea s390/cio: allow to reset channel measurement block
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>
2016-07-14 13:01:49 +02:00
Heiko Carstens a4d9b97cc3 s390/cio: use basic blocks for i/o inline assemblies
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>
2016-06-28 09:32:34 +02:00
Heiko Carstens 7b4ff87cbf s390/cio: use basic blocks for cmf inline assemblies
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>
2016-06-28 09:32:33 +02:00
Martin Schwidefsky 2f82f57763 s390/time: STP sync clock correction
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>
2016-06-13 15:58:19 +02:00
Daniel van Gerpen 99ec1112da s390: use canonical include guard style
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>
2016-06-13 15:58:17 +02:00
Joe Perches baebc70a4d s390: Use pr_warn instead of pr_warning
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>
2016-03-07 13:12:04 +01:00
Sebastian Ott 9f3d6d7a40 s390/cio: update measurement characteristics
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>
2016-01-26 12:47:51 +01:00
Sebastian Ott 61f0bfcf80 s390/cio: ensure consistent measurement state
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>
2016-01-26 12:47:41 +01:00
Sebastian Ott 0d9bfe9123 s390/cio: fix measurement characteristics memleak
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>
2016-01-26 12:47:23 +01:00
Peter Oberparleiter 11b64c8acc s390/cio: Change I/O instructions from inline to normal functions
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>
2015-12-18 14:59:37 +01:00
Peter Oberparleiter 42248979d5 s390/cio: Introduce common I/O layer tracepoints
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>
2015-12-18 14:59:36 +01:00
Peter Oberparleiter 2ab59de7c5 s390/cio: Consolidate inline assemblies and related data definitions
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>
2015-12-18 14:59:34 +01:00
Peter Oberparleiter ac357c4105 s390/cio: Fix incorrect xsch opcode specification
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>
2015-12-18 14:59:34 +01:00
Peter Oberparleiter 62e65da994 s390/cio: Remove unused inline assemblies
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>
2015-12-18 14:59:33 +01:00
Markus Elfring a6e975c5f8 s390: Delete unnecessary checks before the function call "debug_unregister"
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>
2015-11-27 09:24:16 +01:00
Martin Schwidefsky 1a36a39e22 s390/dump: rework CPU register dump code
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>
2015-11-27 09:24:14 +01:00
Sebastian Ott 18e22a1772 s390: add support for ipl devices in subchannel sets > 0
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>
2015-11-11 13:56:27 +01:00
Sebastian Ott cd5dead9d3 s390/cio: simplify css_generate_pgid
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>
2015-11-09 09:10:48 +01:00
Linus Torvalds e627078a0c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
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
  ...
2015-11-04 11:31:31 -08:00
Pierre Morel e510f681d2 s390/cio: de-duplicate subchannel validation
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>
2015-11-03 14:40:50 +01:00
Pierre Morel 8f0ba83178 s390/css: unneeded initialization in for_each_subchannel
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>
2015-11-03 14:40:49 +01:00
Sebastian Ott ef12cb904e s390/cio: move ccw_device_stlck functions
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>
2015-10-27 09:34:44 +01:00
Sebastian Ott 8421d212e8 s390/cio: move ccw_device_call_handler
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>
2015-10-27 09:34:43 +01:00
Heiko Carstens dc6e15556a s390/nmi: remove casts
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>
2015-10-27 09:33:55 +01:00
Sebastian Ott 9d49f86dab s390/cio: introduce pathmask_to_pos
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>
2015-10-14 14:32:04 +02:00
Sebastian Ott ab97d211ef s390/cio: reactivate cmf after hibernate
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>
2015-10-14 14:32:04 +02:00
Sebastian Ott 45bf4b96e6 s390/cio: use kmem_cache for extended measurement block allocation
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>
2015-10-14 14:32:04 +02:00
Sebastian Ott a5e9ca573b s390/cio: fix memleak in channel measurement
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>
2015-10-14 14:32:03 +02:00
Sebastian Ott 616503d1d8 s390/cio: improve locking during cmbe allocation
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>
2015-10-14 14:32:03 +02:00
Sebastian Ott a6ef15652d s390/cio: fix use after free in cmb processing
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>
2015-10-14 14:32:02 +02:00
Sebastian Ott 1bc6664bdf s390/cio: use device_lock during cmb activation
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>
2015-10-14 14:32:02 +02:00
Sebastian Ott 279b8f9a0f s390/cio: cleanup cmb_enable sysfs attr
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>
2015-10-14 14:32:02 +02:00
Eugene Crosser ec6674c638 s390/qdio: fix WARN_ON_ONCE condition
If HiperSockets Completion Queueing is enabled, qdio always
issues a warning, since the condition is always met.
This patch fixes the condition in WARN_ON_ONCE that was always
true.

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>
2015-10-07 04:52:06 -07:00
Peter Senna Tschudin b2f4de8b84 s390: remove unneeded variables
This patch remove unneeded variables used to store return values.

These issues were detected with the Coccinelle script:
scripts/coccinelle/misc/returnvar.cocci

[heiko.carstens@de.ibm.com]: make qeth_l[2/3]_stop() return void

Signed-off-by: Peter Senna Tschudin <peter.senna@gmail.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-08-07 09:57:01 +02:00
Peter Oberparleiter 1d2334cb7d s390/cio: Implement proper Link Incident Record handling
A hardware problem on a FICON link is reported by the Channel Subsystem
to the operating system via a Link Incident Record (LIR). In response,
the operating system should issue a message that enables hardware
service personnel to identify and repair the failing component.

Current Linux LIR handling is broken because LIR data is incorrectly
interpreted and no log message is generated.

This patch fixes Linux LIR handling by implementing a new log message
for LIRs indicating a degraded or non-operational link. Also LIRs are
no longer used to deactivate channel paths because the available data
does not reliably allow to determine the affected channel path.

Signed-off-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Reviewed-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-07-22 09:58:06 +02:00
Peter Oberparleiter b1865401cf s390/cio: Fix comma
After dutifully acting as statement separator for 6 long years, this
comma has finally grown into a full semicolon.

Signed-off-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-07-22 09:58:06 +02:00
Joe Perches c2f0b61d89 s390: remove use of seq_printf return value
The seq_printf return value, because it's frequently misused,
will eventually be converted to void.

See: commit 1f33c41c03 ("seq_file: Rename seq_overflow() to
     seq_has_overflowed() and make public")

Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Sebastian 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: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-15 16:35:25 -07:00
Heiko Carstens 5a79859ae0 s390: remove 31 bit support
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: a960062e58 ("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: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-03-25 11:49:33 +01:00
Martin Schwidefsky 10ad34bc76 s390: add SMT support
The multi-threading facility is introduced with the z13 processor family.
This patch adds code to detect the multi-threading facility. With the
facility enabled each core will surface multiple hardware threads to the
system. Each hardware threads looks like a normal CPU to the operating
system with all its registers and properties.

The SCLP interface reports the SMT topology indirectly via the maximum
thread id. Each reported CPU in the result of a read-scp-information
is a core representing a number of hardware threads.

To reflect the reduced CPU capacity if two hardware threads run on a
single core the MT utilization counter set is used to normalize the
raw cputime obtained by the CPU timer deltas. This scaled cputime is
reported via the taskstats interface. The normal /proc/stat numbers
are based on the raw cputime and are not affected by the normalization.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-01-22 12:16:01 +01:00
Rickard Strandqvist 8ebd51a705 s390/cio: idset.c: remove some unused functions
Removes some functions that are not used anywhere:
idset_clear() idset_sch_get_first()

This was partially found by using a static code analysis program called cppcheck.

Signed-off-by: Rickard Strandqvist <rickard_strandqvist@spectrumdigital.se>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-01-08 10:02:50 +01:00
Sebastian Ott e2578b82c4 s390/eadm: change timeout value
Tests have shown that 5 seconds is sometimes not enough for an IRQ
to arrive (especially when the device is doing garbage collection).
Let's wait a little longer.

Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2014-12-08 09:42:42 +01:00
Linus Torvalds 0429fbc0bd Merge branch 'for-3.18-consistent-ops' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu
Pull percpu consistent-ops changes from Tejun Heo:
 "Way back, before the current percpu allocator was implemented, static
  and dynamic percpu memory areas were allocated and handled separately
  and had their own accessors.  The distinction has been gone for many
  years now; however, the now duplicate two sets of accessors remained
  with the pointer based ones - this_cpu_*() - evolving various other
  operations over time.  During the process, we also accumulated other
  inconsistent operations.

  This pull request contains Christoph's patches to clean up the
  duplicate accessor situation.  __get_cpu_var() uses are replaced with
  with this_cpu_ptr() and __this_cpu_ptr() with raw_cpu_ptr().

  Unfortunately, the former sometimes is tricky thanks to C being a bit
  messy with the distinction between lvalues and pointers, which led to
  a rather ugly solution for cpumask_var_t involving the introduction of
  this_cpu_cpumask_var_ptr().

  This converts most of the uses but not all.  Christoph will follow up
  with the remaining conversions in this merge window and hopefully
  remove the obsolete accessors"

* 'for-3.18-consistent-ops' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: (38 commits)
  irqchip: Properly fetch the per cpu offset
  percpu: Resolve ambiguities in __get_cpu_var/cpumask_var_t -fix
  ia64: sn_nodepda cannot be assigned to after this_cpu conversion. Use __this_cpu_write.
  percpu: Resolve ambiguities in __get_cpu_var/cpumask_var_t
  Revert "powerpc: Replace __get_cpu_var uses"
  percpu: Remove __this_cpu_ptr
  clocksource: Replace __this_cpu_ptr with raw_cpu_ptr
  sparc: Replace __get_cpu_var uses
  avr32: Replace __get_cpu_var with __this_cpu_write
  blackfin: Replace __get_cpu_var uses
  tile: Use this_cpu_ptr() for hardware counters
  tile: Replace __get_cpu_var uses
  powerpc: Replace __get_cpu_var uses
  alpha: Replace __get_cpu_var
  ia64: Replace __get_cpu_var uses
  s390: cio driver &__get_cpu_var replacements
  s390: Replace __get_cpu_var uses
  mips: Replace __get_cpu_var uses
  MIPS: Replace __get_cpu_var uses in FPU emulator.
  arm: Replace __this_cpu_ptr with raw_cpu_ptr
  ...
2014-10-15 07:48:18 +02:00