Commit Graph

134 Commits

Author SHA1 Message Date
Vasily Gorbik
a287a49e67 s390/protvirt: avoid memory sharing for diag 308 set/store
This reverts commit db9492cef4 ("s390/protvirt: add memory sharing for
diag 308 set/store") which due to ultravisor implementation change is
not needed after all.

Fixes: db9492cef4 ("s390/protvirt: add memory sharing for diag 308 set/store")
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-08-06 13:58:34 +02:00
Philipp Rudo
1b2be2071a s390/ipl: Fix detection of has_secure attribute
Use the correct bit for detection of the machine capability associated
with the has_secure attribute. It is expected that the underlying
platform (including hypervisors) unsets the bit when they don't provide
secure ipl for their guests.

Fixes: c9896acc78 ("s390/ipl: Provide has_secure sysfs attribute")
Cc: stable@vger.kernel.org # 5.2
Signed-off-by: Philipp Rudo <prudo@linux.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-07-11 20:40:02 +02:00
Martin Schwidefsky
98587c2d89 s390: simplify disabled_wait
The disabled_wait() function uses its argument as the PSW address when
it stops the CPU with a wait PSW that is disabled for interrupts.
The different callers sometimes use a specific number like 0xdeadbeef
to indicate a specific failure, the early boot code uses 0 and some
other calls sites use __builtin_return_address(0).

At the time a dump is created the current PSW and the registers of a
CPU are written to lowcore to make them avaiable to the dump analysis
tool. For a CPU stopped with disabled_wait the PSW and the registers
do not really make sense together, the PSW address does not point to
the function the registers belong to.

Simplify disabled_wait() by using _THIS_IP_ for the PSW address and
drop the argument to the function.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-05-02 13:54:11 +02:00
Gerald Schaefer
a80313ff91 s390/kernel: introduce .dma sections
With a relocatable kernel that could reside at any place in memory, code
and data that has to stay below 2 GB needs special handling.

This patch introduces .dma sections for such text, data and ex_table.
The sections will be part of the decompressor kernel, so they will not
be relocated and stay below 2 GB. Their location is passed over to the
decompressed / relocated kernel via the .boot.preserved.data section.

The duald and aste for control register setup also need to stay below
2 GB, so move the setup code from arch/s390/kernel/head64.S to
arch/s390/boot/head.S. The duct and linkage_stack could reside above
2 GB, but their content has to be preserved for the decompresed kernel,
so they are also moved into the .dma section.

The start and end address of the .dma sections is added to vmcoreinfo,
for crash support, to help debugging in case the kernel crashed there.

Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Reviewed-by: Philipp Rudo <prudo@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-29 10:47:10 +02:00
Philipp Rudo
c9896acc78 s390/ipl: Provide has_secure sysfs attribute
Provide an interface for userspace so it can find out if a machine is
capeable of doing secure boot. The interface is, for example, needed for
zipl so it can find out which file format it can/should write to disk.

Signed-off-by: Philipp Rudo <prudo@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-29 10:44:04 +02:00
Martin Schwidefsky
937347ac56 s390/ipl: add helper functions to create an IPL report
PR: Adjusted to the use in kexec_file later.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Philipp Rudo <prudo@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-26 12:34:05 +02:00
Martin Schwidefsky
9641b8cc73 s390/ipl: read IPL report at early boot
Read the IPL Report block provided by secure-boot, add the entries
of the certificate list to the system key ring and print the list
of components.

PR: Adjust to Vasilys bootdata_preserved patch set. Preserve ipl_cert_list
for later use in kexec_file.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Philipp Rudo <prudo@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-26 12:34:05 +02:00
Martin Schwidefsky
5f1207fbe7 s390/ipl: provide uapi header for list directed IPL
The IPL parameter block is used as an interface between Linux and
the machine to query and change the boot device and boot options.
To be able to create IPL parameter block in user space and pass it
as segment to kexec provide an uapi header with proper structure
definitions for the block.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-26 12:34:05 +02:00
Martin Schwidefsky
86c74d869d s390/ipl: make ipl_info less confusing
The ipl_info union in struct ipl_parameter_block has the same name as
the struct ipl_info. This does not help while reading the code and the
union in struct ipl_parameter_block does not need to be named. Drop
the name from the union.

Reviewed-by: Hendrik Brueckner <brueckner@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-26 12:34:05 +02:00
Vasily Gorbik
db9492cef4 s390/protvirt: add memory sharing for diag 308 set/store
Add sharing of ipl parameter block for diag 308 set/store calls to allow
kvm access in protected virtualization environment.

Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-10 17:47:22 +02:00
Vasily Gorbik
1e941d3949 s390: move ipl block to .boot.preserved.data section
.boot.preserved.data is a better fit for ipl block than .boot.data
which is discarded after init. Reusing .boot.preserved.data allows to
simplify code a little bit and avoid copying data from .boot.data to
persistent variables.

Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-10 17:47:11 +02:00
Vasily Gorbik
ac1256f826 s390/kasan: reipl and kexec support
Some functions from both arch/s390/kernel/ipl.c and
arch/s390/kernel/machine_kexec.c are called without DAT enabled
(or with and without DAT enabled code paths). There is no easy way
to partially disable kasan for those files without a substantial
rework. Disable kasan for both files for now.

To avoid disabling kasan for arch/s390/kernel/diag.c DAT flag is
enabled in diag308 call. pcpu_delegate which disables DAT is marked
with __no_sanitize_address to disable instrumentation for that one
function.

Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-10-09 11:21:27 +02:00
Vasily Gorbik
49698745e5 s390: move ipl block and cmd line handling to early boot phase
To distinguish zfcpdump case and to be able to parse some of the kernel
command line arguments early (e.g. mem=) ipl block retrieval and command
line construction code is moved to the early boot phase.

"memory_end" is set up correctly respecting "mem=" and hsa_size in case
of the zfcpdump.

arch/s390/boot/string.c is introduced to provide string handling and
command line parsing functions to early boot phase code for the compressed
kernel image case.

Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-10-09 11:21:14 +02:00
Vasily Gorbik
96c0cdbc7c s390/ipl: remove reipl_method and dump_method
reipl_method and dump_method have been used in addition to reipl_type
and dump_type, because a single reipl_type could be achieved with
multiple reipl_method (same for dump_type/method). After dropping
non-diag308_set based reipl methods, there is a single method per
reipl_type/dump_type and reipl_method and dump_method could be simply
removed.

Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-04-10 07:39:00 +02:00
Vasily Gorbik
3b9678472b s390/ipl: correct kdump reipl block checksum calculation
s390 kdump reipl implementation relies on os_info kernel structure
residing in old memory being dumped. os_info contains reipl block,
which is used (if valid) by the kdump kernel for reipl parameters.

The problem is that the reipl block and its checksum inside
os_info is updated only when /sys/firmware/reipl/reipl_type is
written. This sets an offset of a reipl block for "reipl_type" and
re-calculates reipl block checksum. Any further alteration of values
under /sys/firmware/reipl/{reipl_type}/ without subsequent write to
/sys/firmware/reipl/reipl_type lead to incorrect os_info reipl block
checksum. In such a case kdump kernel ignores it and reboots using
default logic.

To fix this, os_info reipl block update is moved right before kdump
execution.

Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-04-10 07:39:00 +02:00
Vasily Gorbik
d485235b00 s390: assume diag308 set always works
diag308 set has been available for many machine generations, and
alternative reipl code paths has not been exercised and seems to be
broken without noticing for a while now. So, cleaning up all obsolete
reipl methods except currently used ones, assuming that diag308 set
always works.

Also removing not longer needed reset callbacks.

Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-04-10 07:38:59 +02:00
Vasily Gorbik
ecc0df0f23 s390/ipl: avoid adding scpdata to cmdline during ftp/dvd boot
Add missing ipl parmblock validity check to append_ipl_scpdata.

Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-04-10 07:38:59 +02:00
Vasily Gorbik
a0832b3aef s390/ipl: correct ipl parmblock valid checks
In some cases diag308_set_works used to be misused as "we have valid ipl
parmblock", which is not the case when diag308 set works, but there is
no ipl parmblock (diag308 store returns DIAG308_RC_NOCONFIG). Such checks
are adjusted to reuse ipl_block_valid instead of diag308_set_works.

Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-04-10 07:38:59 +02:00
Vasily Gorbik
d08091ac96 s390/ipl: rely on diag308 store to get ipl info
For both ccw and fcp boot retrieve ipl info from ipl block received via
diag308 store. Old scsi ipl parm block handling and cio_get_iplinfo are
removed. Ipl type is deducted from ipl block (if valid).

Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-04-10 07:38:59 +02:00
Vasily Gorbik
283abedb1b s390/ipl: move ipl_flags to ipl.c
ipl_flags and corresponding enum are not used outside of ipl.c and will
be reworked in later commits.

Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-04-10 07:38:59 +02:00
Vasily Gorbik
e9627da113 s390/ipl: get rid of ipl_ssid and ipl_devno
ipl_ssid and ipl_devno used to be used during ccw boot when diag308 store
was not available. Reuse ipl_block to store those values.

Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-04-10 07:38:58 +02:00
Vasily Gorbik
bdbfe18595 s390/ipl: unite diag308 and scsi boot ipl blocks
Ipl parm blocks received via "diag308 store" and during scsi boot at
IPL_PARMBLOCK_ORIGIN are merged into the "ipl_block".

Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-04-10 07:38:58 +02:00
Vasily Gorbik
15deb080a6 s390/ipl: ensure loadparm valid flag is set
When loadparm is set in reipl parm block, the kernel should also set
DIAG308_FLAGS_LP_VALID flag.

This fixes loadparm ignoring during z/VM fcp -> ccw reipl and kvm direct
boot -> ccw reipl.

Cc: <stable@vger.kernel.org>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-04-10 07:38:58 +02:00
Martin Schwidefsky
d768bd892f s390: add options to change branch prediction behaviour for the kernel
Add the PPA instruction to the system entry and exit path to switch
the kernel to a different branch prediction behaviour. The instructions
are added via CPU alternatives and can be disabled with the "nospec"
or the "nobp=0" kernel parameter. If the default behaviour selected
with CONFIG_KERNEL_NOBP is set to "n" then the "nobp=1" parameter can be
used to enable the changed kernel branch prediction.

Acked-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-02-05 13:49:17 +01:00
Vasily Gorbik
c50ce358bd s390/ipl: avoid usage of __section(.data)
bss section is cleared before ipl.c code is called or global variables
are used nowadays. Remove stale comment and __section(.data) from
few global variables.

Also removes static/global variables initialization to 0.

Signed-off-by: Vasily Gorbik <gor@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-01-23 07:36:47 +01:00
Greg Kroah-Hartman
a17ae4c3a6 s390: kernel: add SPDX identifiers to the remaining files
It's good to have SPDX identifiers in all files to make it easier to
audit the kernel tree for correct licenses.

Update the arch/s390/kernel/ files with the correct SPDX license
identifier based on the license text in the file itself.  The SPDX
identifier is a legally binding shorthand, which can be used instead of
the full boiler plate text.

This work is based on a script and data from Thomas Gleixner, Philippe
Ombredanne, and Kate Stewart.

Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-11-24 15:37:12 +01:00
Heiko Carstens
978fa72e82 s390: remove named saved segment support
Remove the support to create a z/VM named saved segment (NSS). This
feature is not supported since quite a while in favour of jump labels,
function tracing and (now) CPU alternatives. All of these features
require to write to the kernel text section which is not possible if
the kernel is contained within an NSS.

Given that memory savings are minimal if kernel images are shared and
in addition updates of shared images are painful, the NSS feature can
be removed.

Reviewed-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2017-11-08 09:47:54 +01:00
Heiko Carstens
4130b28f56 s390/ipl: revert Load Normal semantics for LPAR CCW-type re-IPL
This reverts the two commits

7afbeb6df2 ("s390/ipl: always use load normal for CCW-type re-IPL")
0f7451ff3a ("s390/ipl: use load normal for LPAR re-ipl")

The two commits did not take into account that behavior of standby
memory changes fundamentally if the re-IPL method is changed from
Load Clear to Load Normal.

In case of the old re-IPL clear method all memory that was initially
in standby state will be put into standby state again within the
re-IPL process. Or in other words: memory that was brought online
before a re-IPL will be offline again after a reboot.

Given that we use different re-IPL methods depending on the hypervisor
and CCW-type vs SCSI re-IPL it is not easy to tell in advance when and
why memory will stay online or will be offline after a re-IPL.
This does also have other side effects, since memory that is online
from the beginning will be in ZONE_NORMAL by default vs ZONE_MOVABLE
for memory that is offline.

Therefore, before the change, a user could online and offline memory
easily since standby memory was always in ZONE_NORMAL.  After the
change, and a re-IPL, this depended on which memory parts were online
before the re-IPL.

From a usability point of view the current behavior is more than
suboptimal. Therefore revert these changes until we have a better
solution and get back to a consistent behavior. The bad thing about
this is that the time required for a re-IPL will be significantly
increased for configurations with several 100GB or 1TB of memory.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-06-14 15:35:31 +02:00
Heiko Carstens
7afbeb6df2 s390/ipl: always use load normal for CCW-type re-IPL
commit 14890678687c ("s390/ipl: use load normal for LPAR re-ipl")
missed to convert one code path to use load normal semantics for
re-IPL. Convert the missing code path as well.

Fixes: 14890678687c ("s390/ipl: use load normal for LPAR re-ipl")
Reported-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Acked-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-03-02 17:17:15 +01:00
Paul Gortmaker
3994a52b54 s390: kernel: Audit and remove any unnecessary uses of module.h
Historically a lot of these existed because we did not have
a distinction between what was modular code and what was providing
support to modules via EXPORT_SYMBOL and friends.  That changed
when we forked out support for the latter into the export.h file.

This means we should be able to reduce the usage of module.h
in code that is obj-y Makefile or bool Kconfig.  The advantage
in doing so is that module.h itself sources about 15 other headers;
adding significantly to what we feed cpp, and it can obscure what
headers we are effectively using.

Since module.h was the source for init.h (for __init) and for
export.h (for EXPORT_SYMBOL) we consider each change instance
for the presence of either and replace as needed.  Build testing
revealed some implicit header usage that was fixed up accordingly.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-02-17 07:40:31 +01:00
Heiko Carstens
d5ab7a34f9 s390/sclp: make early sclp code readable
This patch

 - unifies the old sclp early code and the sclp early printk code, so
   they can use common functions

 - makes sure all sclp early functions and variables have the same
   "sclp_early" prefix

 - converts the sclp early printk code into readable code by using
   existing data structures instead of hard coded magic arrays

 - splits the early sclp code into two files: sclp_early.c and
   sclp_early_core.c. The core file contains everything that is
   required by the kernel decompressor and may not call functions not
   contained within the core file. Otherwise the result would be a
   link error.

 - changes interrupt handling to be completely synchronous. The old
   early sclp code had a small window which allowed to receive several
   interrupts instead of exactly the single expected interrupt. This
   did hide a subtle potential bug, which is fixed with this large
   rework.

 - contains a couple of small cleanups.

Reviewed-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-02-08 14:13:19 +01:00
Heiko Carstens
90b3baa232 s390: proper type casts for csum_partial invocations
Keep sparse and other static code checkers from emitting warnings like:

arch/s390/kernel/ipl.c:1549:14: warning: incorrect type in assignment (different base types)
arch/s390/kernel/ipl.c:1549:14:    expected unsigned int [unsigned] csum
arch/s390/kernel/ipl.c:1549:14:    got restricted __wsum

All usages in s390 code are ok. Therefore add proper casts.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-01-16 07:27:53 +01:00
Heiko Carstens
d543a106f9 s390: fix initrd corruptions with gcov/kcov instrumented kernels
The early C code within arch/s390/kernel/early.c saves ipl parameters
before the bss section is cleared. When doing that it jumps to code
that is potentially gcov/kcov instrumented. That code in turn will
corrupt an initrd that potentially may reside in the not yet ready to
be used bss section.

Instead of excluding more and more code from gcov/kcov instrumentation
provide an early memmove function which will be used to save ipl
parameters. The verification if these parameters are actually valid
will be done later.

Reviewed-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-12-12 12:11:20 +01:00
Linus Torvalds
015cd867e5 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull s390 updates from Martin Schwidefsky:
 "There are a couple of new things for s390 with this merge request:

   - a new scheduling domain "drawer" is added to reflect the unusual
     topology found on z13 machines.  Performance tests showed up to 8
     percent gain with the additional domain.

   - the new crc-32 checksum crypto module uses the vector-galois-field
     multiply and sum SIMD instruction to speed up crc-32 and crc-32c.

   - proper __ro_after_init support, this requires RO_AFTER_INIT_DATA in
     the generic vmlinux.lds linker script definitions.

   - kcov instrumentation support.  A prerequisite for that is the
     inline assembly basic block cleanup, which is the reason for the
     net/iucv/iucv.c change.

   - support for 2GB pages is added to the hugetlbfs backend.

  Then there are two removals:

   - the oprofile hardware sampling support is dead code and is removed.
     The oprofile user space uses the perf interface nowadays.

   - the ETR clock synchronization is removed, this has been superseeded
     be the STP clock synchronization.  And it always has been
     "interesting" code..

  And the usual bug fixes and cleanups"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (82 commits)
  s390/pci: Delete an unnecessary check before the function call "pci_dev_put"
  s390/smp: clean up a condition
  s390/cio/chp : Remove deprecated create_singlethread_workqueue
  s390/chsc: improve channel path descriptor determination
  s390/chsc: sanitize fmt check for chp_desc determination
  s390/cio: make fmt1 channel path descriptor optional
  s390/chsc: fix ioctl CHSC_INFO_CU command
  s390/cio/device_ops: fix kernel doc
  s390/cio: allow to reset channel measurement block
  s390/console: Make preferred console handling more consistent
  s390/mm: fix gmap tlb flush issues
  s390/mm: add support for 2GB hugepages
  s390: have unique symbol for __switch_to address
  s390/cpuinfo: show maximum thread id
  s390/ptrace: clarify bits in the per_struct
  s390: stack address vs thread_info
  s390: remove pointless load within __switch_to
  s390: enable kcov support
  s390/cpumf: use basic block for ecctr inline assembly
  s390/hypfs: use basic block for diag inline assembly
  ...
2016-07-26 12:22:51 -07:00
Michael Holzheu
5419447e21 Revert "s390/kdump: Clear subchannel ID to signal non-CCW/SCSI IPL"
This reverts commit 852ffd0f4e.

There are use cases where an intermediate boot kernel (1) uses kexec
to boot the final production kernel (2). For this scenario we should
provide the original boot information to the production kernel (2).
Therefore clearing the boot information during kexec() should not
be done.

Cc: stable@vger.kernel.org # v3.17+
Reported-by: Steffen Maier <maier@linux.vnet.ibm.com>
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-06-28 09:24:27 +02:00
Heiko Carstens
0599eead58 s390/ipl: rename diagnose enums
Rename DIAG308_IPL and DIAG308_DUMP to DIAG308_LOAD_CLEAR and
DIAG308_LOAD_NORMAL_DUMP to better reflect the associated IPL
functions.

Suggested-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Suggested-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Reviewed-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-06-13 15:58:26 +02:00
Heiko Carstens
0f7451ff3a s390/ipl: use load normal for LPAR re-ipl
Avoid clearing memory for CCW-type re-ipl within a logical
partition. This can save a significant amount of time if a logical
partition contains a lot of memory.

On the other hand we still clear memory if running within a second
level hypervisor, since the hypervisor can simply free all memory that
was used for the guest.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Reviewed-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-06-13 15:58:26 +02:00
Heiko Carstens
6c22c98637 s390: avoid extable collisions
We have some inline assemblies where the extable entry points to a
label at the end of an inline assembly which is not followed by an
instruction.

On the other hand we have also inline assemblies where the extable
entry points to the first instruction of an inline assembly.

If a first type inline asm (extable point to empty label at the end)
would be directly followed by a second type inline asm (extable points
to first instruction) then we would have two different extable entries
that point to the same instruction but would have a different target
address.

This can lead to quite random behaviour, depending on sorting order.

I verified that we currently do not have such collisions within the
kernel. However to avoid such subtle bugs add a couple of nop
instructions to those inline assemblies which contain an extable that
points to an empty label.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-06-13 15:58:26 +02:00
Heiko Carstens
72a9b02d3b s390: use __section macro everywhere
Small cleanup patch to use the shorter __section macro everywhere.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-06-13 15:58:23 +02:00
Heiko Carstens
fecc868a66 s390: remove all usages of PSW_ADDR_AMODE
This is a leftover from the 31 bit area. For CONFIG_64BIT the usual
operation "y = x | PSW_ADDR_AMODE" is a nop. Therefore remove all
usages of PSW_ADDR_AMODE and make the code a bit less confusing.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
2016-01-19 12:14:02 +01:00
Heiko Carstens
c667aeacc1 s390: rename struct _lowcore to struct lowcore
Finally get rid of the leading underscore. I tried this already two or
three years ago, however Michael Holzheu objected since this would
break the crash utility (again).

However Michael integrated support for the new name into the crash
utility back then, so it doesn't break if the name will be changed
now.  So finally get rid of the ever confusing leading underscore.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-01-11 12:27:15 +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
e0bedada3a s390/ipl: fix out of bounds access in scpdata_write
The input buffer in reipl_fcp_scpdata_write is accessed out of bounds
when an offset is specified. The problem is that the offset refers to
the data we should write to and not to the buffer we read from.

So instead of
        memcpy(scp_data, buf + off, count);
we could just do
        memcpy(scp_data + off, buf, count);

However we not only modify the data but also store its length. For this to
work we'd need to remember a state per open FH. Since that's not possible
with sysfs callbacks let's just fail when an offset is specified.

Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Acked-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-11-11 09:07:06 +01:00
Martin Schwidefsky
1ec2772e0c s390/diag: add a statistic for diagnose calls
Introduce /sys/debug/kernel/diag_stat with a statistic how many diagnose
calls have been done by each CPU in the system.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-10-14 14:32:06 +02:00
Sebastian Ott
3be7ae6350 s390/ipl: cleanup macro usage
ipl.c uses 3 different macros to create a sysfs show function for ipl
attributes. Define IPL_ATTR_SHOW_FN which is used by all macros.

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>
2015-03-25 11:49:50 +01:00
Sebastian Ott
0f024379ff s390/ipl: cleanup shutdown_action attributes
Use macros wherever applicable and create a shutdown_action attribute
group to simplify the code.

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>
2015-03-25 11:49:49 +01:00
Sebastian Ott
22d557abf7 s390/ipl: cleanup bin attr usage
Use macros wherever applicable and put bin_attributes inside attribute_groups
to simplify/remove some code.

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>
2015-03-25 11:49:48 +01:00
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