Implement magic sysrequest handling for the VT220 terminal (also known as
the Integrated ASCII console on the HMC/SE).
To invoke a "magic sysrequest" function, press "Ctrl+o" followed by a
second character that designates the debugging function.

The handling of the sysrq is scheduled away from the SCLP IRQ context;
because large amounts of sysrq output might fill up the console buffers.
The console might deadlock because it cannot empty the buffers while still
in the receiving IRQ context.  This behavior is the same as for the SCLP
console.
Reported-by: NHorst Weber <hweber@de.ibm.com>
Signed-off-by: NHendrik Brueckner <brueckner@linux.vnet.ibm.com>
Reviewed-by: NPeter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Extract the sysrq handling from the ctrlchar_handle() into a separate
function that can be directly used by other users.

Introduce a new sysrq_work structure to embed the work_struct and to
specify the magic sysrq function to be invoked.
Signed-off-by: NHendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The NUMA system call "__ARCH_WANT" defines are not used by the
Linux kernel, therefore remove them.

Fixes: 9df62adffeb0 ("s390/numa: add core infrastructure")
Signed-off-by: NMichael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

If a 3270 terminal is disconnected and later reconnected again,
it gets an unsolicited device end. This is currently ignored and
you have to hit the clear key to get the screen redrawn.
Add an automatic full redraw of the screen for this case.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

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: NDavid Binderman <dcb314@hotmail.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

With the removal of the dynamic reallocation of page tables for
KVM (see git commit 0b46e0a3)
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: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The error messages in pci_insn are for debug purposes only. Move
them to the debugfs.
Reviewed-by: NGerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: NSebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: NMartin 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: NHeiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: NHendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: NMartin 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: NHeiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NMartin 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: NHeiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: NHendrik Brueckner <brueckner@linux.vnet.ibm.com>
Acked-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NMartin 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: NUlrich Weigand <uweigand@de.ibm.com>
Reviewed-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin 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: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin 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: NHeiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: NDavid Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: NMartin 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: NHeiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: NDavid Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: NMartin 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: e8054b65 ("s390/numa: add topology tree infrastructure")
Reported-and-tested-by: NEvgeny Cherkashin <Eugene.Crosser@ru.ibm.com>
Signed-off-by: NMichael Holzheu <holzheu@linux.vnet.ibm.com>
Acked-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin 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: NPeter Oberparleiter <oberpar@linux.vnet.ibm.com>
Reviewed-by: NSebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: NStefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: NMartin 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: NStefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: NMartin 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: NMartin 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: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMichael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: NMartin 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: a6d67864 ("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: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin 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: NPeter Senna Tschudin <peter.senna@gmail.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin 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: NPeter Senna Tschudin <peter.senna@gmail.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin 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: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMichael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: NMartin 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: NMartin 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: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Signed-off-by: NPhilipp Hachtmann <phacht@linux.vnet.ibm.com>
Signed-off-by: NMartin 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: NMichael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: NMartin 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: NPhilipp Hachtmann <phacht@linux.vnet.ibm.com>
Signed-off-by: NMichael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: NMartin 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: NPhilipp Hachtmann <phacht@linux.vnet.ibm.com>
Signed-off-by: NMichael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

With NUMA support for s390, arch_add_memory() needs to respect the nid
parameter.
Signed-off-by: NGerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Force get_user_page() to take the slow path for NUMA migration pages.
Signed-off-by: NGerald Schaefer <geraldsc@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Define pte_protnone and pmd_protnone for NUMA memory migration.
Signed-off-by: NMartin 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: NDavid Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: NMartin 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: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NHendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: NMartin 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: NGerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: NSebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: NMartin 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: NGerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: NSebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Free bus resources when the allocation/registration of the bus failed.
Reviewed-by: NGerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: NSebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: NMartin 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: NCornelia 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: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin 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: NMichael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin 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: NMartin Schwidefsky <schwidefsky@de.ibm.com>