Fix a couple of warnings like this:
[linux-4.2-rc7/drivers/s390/block/dcssblk.c:553]:
(style) Array index 'j' is used before limits check.
Reported-by: David Binderman <dcb314@hotmail.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
With the removal of the dynamic reallocation of page tables for
KVM (see git commit 0b46e0a3ec)
the page table allocation / freeing code can be simplified.
The page table free code can now use the alloc_pgste bit in the
mm context to decide if a page table is 2K or 4K, there is no mix
of different sized page tables anymore. This eliminates the need
to use "page->_mapcount == 0" to check for 4K page table.
Use the lower two bits in page->_mapcount to indicate which
2K fragments of the 4K page are in use.
As 31-bit support is gone, remove the two defines ALLOC_ORDER
and FRAG_MASK and use the constants directly where appropriate.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The error messages in pci_insn are for debug purposes only. Move
them to the debugfs.
Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Change machine_check_init() to an early_initcall(). This makes sure it will
be called before all other cpus are online and therfore saves us a lot of
pointless smp_call_function() calls.
The control register settings will be forwarded to the other cpus when they
will be brought online.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
There is no need to busy loop and monopolize a cpu for up to ~2 seconds.
The code in question that calls mdelay() is preemptible anyway, so better
let the kernel schedule different processes than just looping and causing
unnecessary delays.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The z/VM driver sets bit "63-22" in control register zero to one in order
to enable the CP Service interrupt (0x2603). However the irq subclass mask
that normally corresponds to the CP Service interrupt is
"63-54" (== "63-22-32").
So it looks like the author read the documentation with the 32 bit sized
cr0 register bit positions (== 22), but didn't realize that bit numbers
change, if applied to a 64 bit register (== 54) due to the numbering
scheme.
Also use irq_subclass_register() instead if ctl_set_bit() since multiple
services depend on the service signal subclass mask, which is the correct
bit. This also explains why nobody noticed the bug, since the bit is always
enabled anyway (e.g. pfault).
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The novx parameter disables the vector facility but the HWCAP_S390_VXRS
bit in the ELf hardware capabilies is always set if the machine has
the vector facility. If the user space program uses the "vx" string
in the features field of /proc/cpuinfo to utilize vector instruction
it will crash if the novx kernel paramter is set.
Convert setup_hwcaps to an arch_initcall and use MACHINE_HAS_VX to
decide if the HWCAPS_S390_VXRS bit needs to be set.
Cc: stable@vger.kernel.org # 3.18+
Reported-by: Ulrich Weigand <uweigand@de.ibm.com>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
get_user() and put_user() are inline functions in the meantime
again. Both will generate the mvcos instruction if compiled
with -march=z10 (or greater).
The kernel parameter "uaccess_primary" can only change the behavior
of out-of-line uaccess functions like copy_from_user() to not use
the mvcos instruction, but not for the above named inlined functions.
Therefore it is quite useless and the parameter can be removed.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Remove two more statements which always evaluate to 'false'.
These are more leftovers from the 31 bit era.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Remove the two facility bits
50 - constrained transactional-execution facility
74 - transactional-execution facility
from the required facilities if the kernel is built with -march=zEC12.
E.g. z/VM 6.3 doesn't virtualize the TX facility yet. Therefore a kernel
built with -march=zEC12 and ipl'ed on a zEC12 machine as a z/VM 6.3 guest
will emit a message about the missing facilities and stop working.
The kernel however doesn't make use of the TX facility, therefore remove
the two TX related facility bits and fix this unpleasant behavior.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
By accident this level has been removed by the NUMA infrastructure patch.
For non-NUMA systems with CPUs that span more than one book, this makes
the scheduler only use one of the books and the other books remain idle.
Fix this and re-add the missing level.
For NUMA and non-NUMA we have the following scheduling domains and groups:
- SMT (Groups: CPU threads)
- MC (Groups: Cores)
- BOOK (Groups: Books)
For the non-NUMA case we have one last level scheduling domain:
- DIE (Groups: Whole system, has all CPUs -> cpu_cpu_mask)
For the NUMA case we have the following two last level scheduling domains:
- DIE (Groups: NUMA nodes -> cpu_cpu_mask -> returns node siblings)
- NUMA (Groups: Whole system, has all CPUs -> created in sched_init_numa())
Fixes: e8054b654b ("s390/numa: add topology tree infrastructure")
Reported-and-tested-by: Evgeny Cherkashin <Eugene.Crosser@ru.ibm.com>
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This patch adds an enhanced detection for control unit initiated
reconfiguration request scope.
The first approach assumed the scope of the reconfiguration request
to be restricted to the path on which the message was received.
The enhanced approach determines the full scope of the reconfiguration
request by evaluating additional path and device selection information
contained in the reconfiguration message.
Reviewed-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Reviewed-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
DASD path verification requires the usage of sleep_on_immediatly to
ensure that no other I/O request is blocking the recovery of
disconnected devices. But two concurrent path verification workers for
the same device may kill each others requests due to the usage of the
immediate sleep_on function. This may lead to unsuccessful path
verifications.
Prevent that two parallel path verification workers conflict with
each other by implementing a device flag signalling a already running
worker.
Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
As proposed by Andy Lutomirski create the SysV and the GNU hash
for the vdso objects. This may make some dynamic loaders a bit
faster.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The core to node mapping data consumes about 2 KB bss data. To save memory
for the non-NUMA case, make the data dynamic. In addition change the
"core_to_node" array from "int" to "s32" which saves 1 KB also for the
NUMA case.
Suggested-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
__delay is exported by most architectures, and may be used in modules.
Since it is not exported for s390, s390:allmodconfig currently fails
to build with
ERROR: "__delay" [drivers/net/phy/mdio-octeon.ko] undefined!
Fixes: a6d6786452 ("net: mdio-octeon: Modify driver to work on both
ThunderX and Octeon")
Cc: Radha Mohan Chintakuntla <rchintakuntla@cavium.com>
Cc: David Daney <david.daney@cavium.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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>
Remove unneeded semicolon.
The semantic patch that detects this change is available
at scripts/coccinelle/misc/semicolon.cocci.
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>
Since we are already protected by the "sched_domains_mutex" lock, we can
safely remove the topology lock.
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The MT scaling values are updated on each calll to do_account_vtime.
This function is called for each HZ interrupt and for each context
switch. Context switch can happen often, the STCCTM instruction
on this path is noticeable. Limit the updates to once per jiffy.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
x86 will wire up all syscalls reachable via sys_socketcall. Therefore this
will yield a lot of warnings from the checksyscalls.sh scripts on s390
where we currently don't wire them up directly.
This might change in the future, but this needs to be done carefully in
order to not break anything.
For the time being just tell the checksyscalls script to ignore the missing
syscalls on s390.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
NUMA emulation (aka fake NUMA) distributes the available memory to nodes
without using real topology information about the physical memory of the
machine.
Splitting the system memory into nodes replicates the memory management
structures for each node. Particularly each node has its own "mm locks"
and its own "kswapd" task.
For large systems, under certain conditions, this results in improved
system performance and/or latency based on reduced pressure on the mm
locks and the kswapd tasks.
NUMA emulation distributes CPUs to nodes while respecting the original
machine topology information. This is done by trying to avoid to separate
CPUs which reside on the same book or even on the same MC. Because the
current Linux scheduler code requires a stable cpu to node mapping, cores
are pinned to nodes when the first CPU thread is set online.
This patch is based on the initial implementation from Philipp Hachtmann.
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
NUMA emulation needs proper means to mangle the book/mc/core topology
of the machine. The topology tree (toptree) consistently maintains cpu
masks for the root, each node, and all leaves of the tree while the
user may use the toptree functions to rearrange the tree in various
ways.
This patch contains several changes from Michael Holzheu.
Signed-off-by: Philipp Hachtmann <phacht@linux.vnet.ibm.com>
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Enable core NUMA support for s390 and add one simple default mode "plain"
that creates one single NUMA node.
This patch contains several changes from Michael Holzheu.
Signed-off-by: Philipp Hachtmann <phacht@linux.vnet.ibm.com>
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
With NUMA support for s390, arch_add_memory() needs to respect the nid
parameter.
Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Force get_user_page() to take the slow path for NUMA migration pages.
Signed-off-by: Gerald Schaefer <geraldsc@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Right now we use the address of the sie control block as tag for
the sampling data. This is hard to get for users. Let's just use
the PID of the cpu thread to mark the hardware samples.
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
All calls to save_fpu_regs() specify the fpu structure of the current task
pointer as parameter. The task pointer of the current task can also be
retrieved from the CPU lowcore directly. Remove the parameter definition,
load the __LC_CURRENT task pointer from the CPU lowcore, and rebase the FPU
structure onto the task structure. Apply the same approach for the
load_fpu_regs() function.
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Make sure that we use the pci_rescan_remove_lock when we remove
or add functions from/to the bus.
Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Receiving error events for a pci function that's currently not in use
will crash the kernel. For example the procedure for FW upgrades might
include:
* remove the function from Linux
* apply FW upgrade
* rescan for new functions
Receiving an event during the FW upgrade will result in a use after free
when printing the functions name. Just print "n/a" in such cases.
Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Free bus resources when the allocation/registration of the bus failed.
Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The public mailing lists and personal email addresses are sufficient.
No need for an extra generic email address.
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Ursula Braun <ursula.braun@de.ibm.com>
Cc: Ingo Tuchscherer <ingo.tuchscherer@de.ibm.com>
Cc: Steffen Maier <maier@linux.vnet.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Section mismatch in reference from the function __smp_store_cpu_state()
to the function .init.text:memblock_alloc()
The function __smp_store_cpu_state() references
the function __init memblock_alloc().
Reviewed-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>
The 31-bit assembler code for the early sclp console is error
prone as git commit fde24b54d976cc123506695c17db01438a11b673
"s390/sclp: clear upper register halves in _sclp_print_early"
has shown.
Convert the assembler code to C.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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>
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>
Dropping kernel messages during a console-buffer-full condition
is preferable to halting the system until console messages are
delivered, especially for production systems.
Update default for sclp_console_drop kernel parameter accordingly.
Signed-off-by: Peter Oberparleiter <peter.oberparleiter@linux.vnet.ibm.com>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Inline get_zdev to save ~200 bytes of kernel text for CONFIG_PCI=y.
Also rename the function to to_zpci to make clear that we don't do
reference counting here.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
If a machine checks is received while the CPU is in the kernel, only
the s390_do_machine_check function will be called. The call to
s390_handle_mcck is postponed until the CPU returns to user space.
Because of this it is safe to use the asynchronous stack for machine
checks even if the CPU is already handling an interrupt.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Reorder the instructions of UPDATE_VTIME to improve superscalar execution,
remove duplicate checks for problem-state from the asynchronous interrupt
handlers, and move the check for problem-state from the synchronous
exit path to the program check path as it is only needed for program
checks inside the kernel.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Currently there are two mechanisms to deal with cleanup work due to
interrupts. The HANDLE_SIE_INTERCEPT macro is used to undo the changes
required to enter SIE in sie64a. If the SIE instruction causes a program
check, or an asynchronous interrupt is received the HANDLE_SIE_INTERCEPT
code forwards the program execution to sie_exit.
All the other critical sections in entry.S are handled by the code in
cleanup_critical that is called by the SWITCH_ASYNC macro.
Move the sie64a function to the beginning of the critical section and
add the code from HANDLE_SIE_INTERCEPT to cleanup_critical. Add a special
case for the sie64a cleanup to the program check handler.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The HANDLE_SIE_INTERCEPT macro is used in the interrupt handlers
and the program check handler to undo a few changes done by sie64a.
Among them are guest vs host LPP, the gmap ASCE vs kernel ASCE and
the bit that indicates that SIE is currently running on the CPU.
There is a race of a voluntary SIE exit vs asynchronous interrupts.
If the CPU completed the SIE instruction and the TM instruction of
the LPP macro at the time it receives an interrupt, the interrupt
handler will run while the LPP, the ASCE and the SIE bit are still
set up for guest execution. This might result in wrong sampling data,
but it will not cause data corruption or lockups.
The critical section in sie64a needs to be enlarged to include all
instructions that undo the changes required for guest execution.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Use the module_cpu_feature_match() module init function to add an
module alias based on required CPU features. The modules are
automatically loaded on hardware that supports the required CPU features.
Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Add support for the generic CPU feature modalias implementation that wires
up optional CPU features to udev-based module autoprobing.
The <asm/cpufeature.h> file provides definitions to map CPU features to
s390 ELF hardware capabilities.
Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
A section mismatch warning is reported if an __init annotated function is
specified for module_cpu_feature_match().
Change the module_cpu_feature_match() function and annotate the generated
cpu_feature_match_* function as __init.
Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Improve the save and restore behavior of FPU register contents to use the
vector extension within the kernel.
The kernel does not use floating-point or vector registers and, therefore,
saving and restoring the FPU register contents are performed for handling
signals or switching processes only. To prepare for using vector
instructions and vector registers within the kernel, enhance the save
behavior and implement a lazy restore at return to user space from a
system call or interrupt.
To implement the lazy restore, the save_fpu_regs() sets a CPU information
flag, CIF_FPU, to indicate that the FPU registers must be restored.
Saving and setting CIF_FPU is performed in an atomic fashion to be
interrupt-safe. When the kernel wants to use the vector extension or
wants to change the FPU register state for a task during signal handling,
the save_fpu_regs() must be called first. The CIF_FPU flag is also set at
process switch. At return to user space, the FPU state is restored. In
particular, the FPU state includes the floating-point or vector register
contents, as well as, vector-enablement and floating-point control. The
FPU state restore and clearing CIF_FPU is also performed in an atomic
fashion.
For KVM, the restore of the FPU register state is performed when restoring
the general-purpose guest registers before the SIE instructions is started.
Because the path towards the SIE instruction is interruptible, the CIF_FPU
flag must be checked again right before going into SIE. If set, the guest
registers must be reloaded again by re-entering the outer SIE loop. This
is the same behavior as if the SIE critical section is interrupted.
Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Older binutils versions do not include support for the vector instruction
formats. Add assembler macros for vector instruction mnemonics to easily
encode and generate vector instructions.
Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Make the floating-point save area dynamically allocated and uses a flag
to distinguish whether a task uses floating-point or vector registers.
Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Martin Schwidefsky