The current way of adding new instructions to the opcode tables is
painful and error prone. Therefore add, similar to binutils, a text
file which contains all opcodes and the corresponding mnemonics and
instruction formats.

A small gen_opcode_table tool then generates a header file with the
required enums and opcode table initializers at the prepare step of
the kernel build.

This way only a simple text file has to be maintained, which can be
rather easily extended.

Unlike before where there were plenty of opcode tables and a large
switch statement to find the correct opcode table, there is now only
one opcode table left which contains all instructions. A second opcode
offset table now contains offsets within the opcode table to find
instructions which have the same opcode prefix. In order to save space
all 1-byte opcode instructions are grouped together at the end of the
opcode table. This is also quite similar to like it was before.

In addition also move and change code and definitions within the
disassembler. As a side effect this reduces the size required for the
code and opcode tables by ~1.5k.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>

insn_to_mnemonic() was introduced ages ago for KVM debugging, but is
unused in the meantime. Therefore remove it.
Acked-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>

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: NHendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>

The reworked version of the random device driver now calls
the arch_get_random_* functions on a very high frequency.
It does about 100.000 calls to arch_get_random_long for
providing 10 MB via /dev/urandom. Each invocation was
fetching entropy from the hardware random generator which
has a rate limit of about 4 MB/s. As the trng invocation
waits until enough entropy is gathered, the random device
driver is slowed down dramatically.

The s390 true random generator is not designed for such
a high rate. The TRNG is more designed to be used together
with the arch_get_random_seed_* functions. This is similar
to the way how powerpc has implemented their arch random
functionality.

This patch removes the invocations of the s390 TRNG for
arch_get_random_long() and arch_get_random_int() but leaving
the invocations for arch_get_random_seed_long() and
arch_get_random_seed_int(). So the s390 arch random
implementation now contributes high quality entropy to
the kernel random device for reseeding.
Signed-off-by: NHarald Freudenberger <freude@linux.vnet.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>

As of today QEMU does not provide the AIS facility to its guest.  This
prevents Linux guests from using PCI devices as the ais facility is
checked during init. As this is just a performance optimization, we can
move the ais check into the code where we need it (calling the SIC
instruction). This is used at initialization and on interrupt. Both
places do not require any serialization, so we can simply skip the
instruction.

Since we will now get all interrupts, we can also avoid the 2nd scan.
As we can have multiple interrupts in parallel we might trigger spurious
irqs more often for the non-AIS case but the core code can handle that.
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: NPierre Morel <pmorel@linux.vnet.ibm.com>
Reviewed-by: NHalil Pasic <pasic@linux.vnet.ibm.com>
Acked-by: NSebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>

__LC_MCESAD is currently 4528 /* offsetof(struct lowcore, mcesad) */
that would require long-displacement facility for lg, which we don't
have on z900.

Fixes: 3037a52f ("s390/nmi: do register validation as early as possible")
Signed-off-by: NVasily Gorbik <gor@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

s390 is big-endian only but sparse assumes the same endianness
as the building machine.
This is problematic for code which expect __BYTE_ORDER__ being
correctly predefined by the compiler which sparse can then
pre-process differently from what gcc would, depending on the
building machine endianness.

Fix this by letting sparse know about the architecture endianness.
Signed-off-by: NLuc Van Oostenryck <luc.vanoostenryck@gmail.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The decompressor for bzImage prints two informational messages which are
not really helpful. The decompression step is fast and if something bad
happens an error message will be printed. Remove the noise.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Add the hardware counters that are available with z14.  With z14,
the number of problem-state counters is reduced.  The initialization
is updated respectively.
Signed-off-by: NHendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The validation of the CPU registers in the machine check handler is
currently split into two parts. The first part is done at the start
of the low level mcck_int_handler function, this includes the CPU
timer register and the general purpose registers.
The second part is done a bit later in s390_do_machine_check for all
the other registers, including the control registers, floating pointer
control, vector or floating pointer registers, the access registers,
the guarded storage registers, the TOD programmable registers and the
clock comparator.

This is working fine to far but in theory a future extensions could
cause the C code to use registers that are not validated yet. A better
approach is to validate all CPU registers in "safe" assembler code
before any C function is called.
Reviewed-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The machine check extended save area is needed to store the vector
registers and the guarded storage control block when a CPU is
interrupted by a machine check.

Move the slab cache allocation of the full save area to nmi.c,
for early boot use a static __initdata block.
Reviewed-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The nmi.h header has some constant defines for control register bits.
These definitions should really be located in ctl_reg.h. Move and
rename the defines.
Reviewed-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>

Add a decoding union for the bits in control registers 2 and use
'union ctlreg0' and 'union ctlreg2' in update_cr_regs to improve
readability.
Reviewed-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>

The smp_send_stop() function can be called from s390_handle_damage
while DAT is off. This happens if a machine check indicates that
kernel gprs or control registers can not be restored. The function
smp_send_stop reenables DAT via __load_psw_mask. That should work
for the case of lost kernel gprs and the system will do the expected
stop of all CPUs. But if control registers are lost, in particular
CR13 with the home space ASCE, interesting secondary crashes may
occur.

Make smp_emergency_stop callable from nmi.c and remove the cpumask
argument. Replace the smp_send_stop call with smp_emergency_stop in
the s390_handle_damage function.

In addition add notrace and NOKPROBE_SYMBOL annotations for all
functions required for the emergency shutdown.
Reviewed-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The boot_vdso_data variable is related to the vdso code, the magic of the
initial vdso area for the early boot and the replacement of it in vdso_init
should all be put into vdso.c.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Enable niai instruction in the spinlock code at run-time for machines
on which facility 49 is available (zEC12 and newer).
Signed-off-by: NVasily Gorbik <gor@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Implement CPU alternatives, which allows to optionally patch newer
instructions at runtime, based on CPU facilities availability.

A new kernel boot parameter "noaltinstr" disables patching.

Current implementation is derived from x86 alternatives. Although
ideal instructions padding (when altinstr is longer then oldinstr)
is added at compile time, and no oldinstr nops optimization has to be
done at runtime. Also couple of compile time sanity checks are done:
1. oldinstr and altinstr must be <= 254 bytes long,
2. oldinstr and altinstr must not have an odd length.

alternative(oldinstr, altinstr, facility);
alternative_2(oldinstr, altinstr1, facility1, altinstr2, facility2);

Both compile time and runtime padding consists of either 6/4/2 bytes nop
or a jump (brcl) + 2 bytes nop filler if padding is longer then 6 bytes.

.altinstructions and .altinstr_replacement sections are part of
__init_begin : __init_end region and are freed after initialization.
Signed-off-by: NVasily Gorbik <gor@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

debug_event_common memsets the active debug entry with zeros to
prevent stale data leakage. This is overwritten with the actual
debug data in the next step. Only write zeros to that part of the
debug entry that's not used by new debug data.

Micro benchmarks show a 2-10% reduction of cpu cycles with this
approach.
Signed-off-by: NSebastian Ott <sebott@linux.vnet.ibm.com>
Acked-by: NMichael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

debug_event currently truncates the data if used with a size larger than
the buf_size of the debug feature. For lots of callers of this function,
wrappers have been implemented that loop until all data is handled.

Move that functionality into debug_event_common and get rid of the wrappers.
Signed-off-by: NSebastian Ott <sebott@linux.vnet.ibm.com>
Acked-by: NMichael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Before kexec boots to a crash kernel it checks whether the image in memory
changed after load. This is done by the function kdump_csum_valid, which
returns true, i.e. an int != 0, on success and 0 otherwise. In other words
when kdump_csum_valid returns an error code it means that the validation
succeeded. This is not only counterintuitive but also produces the wrong
result if the kernel was build without CONFIG_CRASH_DUMP. Fix this by
making kdump_csum_valid return a bool.
Signed-off-by: NPhilipp Rudo <prudo@linux.vnet.ibm.com>
Acked-by: NMichael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The debug feature code hasn't been touched in ages and the code also
looks like this. Therefore clean up the code so it looks a bit more
like current coding style.

There is no functional change - actually I made also sure that the
generated code with performance_defconfig is identical.
A diff of old vs new with "objdump -d" is empty.

The code is still not checkpatch clean, but that was not the goal.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

For an unknown reason the s390 kprobes instruction replacement
function modifies the kprobe_status of the current CPU to
KPROBE_SWAP_INST. This was supposed to catch traps that happened
during instruction patching. Such a fault is not supposed to happen,
and silently discarding such a fault is certainly also not what we
want. In fact s390 is the only architecture which has this odd piece
of code.

Just remove this and behave like all other architectures. This was
pointed out by Jens Remus.
Reported-by: NJens Remus <jremus@linux.vnet.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Just some trivial changes like removing the extern keyword from the
header file, renaming arguments to match the man pages, and whitespace
removal.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Like for the memset16/32/64 variants avoid that subsequent mvc
instructions depend on each other since that might have negative
performance impacts.

This patch is currently hardly relevant since at least gcc 7.1
generates only inline memset code and not a single memset call.
However there is no reason to not provide an optimized version
just in case gcc generates memset calls again, like it did in
the past.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Use memset64 instead of the (now) open-coded variant clear_table.
Performance wise there is no difference.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Provide fast versions of the new memset variants. E.g. the generic
memset64 is ten times slower than the optimized version if used on a
whole page.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Add a syscall of s390_sthyi to implement STHYI instruction in LPAR
which reuses the implementation for KVM by Janosch Frank -
commit 95ca2cb5 ("KVM: s390: Add sthyi emulation").

STHYI(Store Hypervisor Information) is an emulated z/VM instruction that
provides a guest with basic information about the layers it is running
on. This includes information about the cpu configuration of both the
machine and the lpar, as well as their names, machine model and
machine type. This information enables an application to determine the
maximum capacity of CPs and IFLs available to software.

For the arguments of s390_sthyi, code shall be 0 and flags is reserved for
future use, info is the output argument to store the required hypervisor
info.
Signed-off-by: NQingFeng Hao <haoqf@linux.vnet.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

STHYI requires extensive locking in the higher hypervisors and is
very computational/memory expensive. Therefore we cache the retrieved
hypervisor info whose valid period is 1s with mutex to allow concurrent
access. rw semaphore can't benefit here due to cache line bounce.
Signed-off-by: NQingFeng Hao <haoqf@linux.vnet.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

As we need to support sthyi instruction on LPAR too, move the common code
to kernel part and kvm related code to intercept.c for better reuse.
Signed-off-by: NQingFeng Hao <haoqf@linux.vnet.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

We never optimized our rwsem inline assemblies to make use of the new
atomic instructions. The generic rwsem implementation implicitly makes
use of the new instructions, since it implements the required rwsem
primitives with atomic operations, which we did optimize.

However even when compiling for old architectures the generic variant
still generates better code. So it's time to simply remove our old
code and switch to the generic implementation.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

This instruction came with a z/VM extension and not with a specific
machine generation.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Remove a couple of instructions that are listed twice.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The e7 opcode table does not have an end marker. Hence when trying to
find an unknown e7 instruction the code will access memory behind the
table until it finds something that matches the opcode, or the kernel
crashes, whatever comes first.

This affects not only the in-kernel disassembler but also uprobes and
kprobes which refuse to set a probe on unknown instructions, and
therefore search the opcode tables to figure out if instructions are
known or not.

Cc: <stable@vger.kernel.org> # v3.18+
Fixes: 3585cb02 ("s390/disassembler: add vector instructions")
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

There is no recent user space application available anymore which still
supports this old virtio transport. Additionally, commit 3b2fbb3f
("virtio/s390: deprecate old transport") introduced a deprecation message
in the driver, and apparently nobody complained so far that it is still
required. So let's simply remove it.
Signed-off-by: NThomas Huth <thuth@redhat.com>
Reviewed-by: NCornelia Huck <cohuck@redhat.com>
Acked-by: NHalil Pasic <pasic@linux.vnet.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

When grouping devices, the ccwgroup core only checks whether all of the
devices are bound to the same ccw_driver. It has no means of checking
if the requesting ccwgroup driver actually supports this device type.
qeth implements its own device matching in qeth_core_probe_device(),
while ctcm and lcs currently have no sanity-checking at all.

Enable ccwgroup drivers to optionally defer the device type checking to
the ccwgroup core, by specifying their supported ccw_driver.
This allows us drop the device type matching from qeth, and improves
the robustness of ctcm and lcs.
Signed-off-by: NJulian Wiedmann <jwi@linux.vnet.ibm.com>
Acked-by: NSebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: NPeter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

This patch introduces gcm(aes) support into the aes_s390 kernel module.
Signed-off-by: NPatrick Steuer <patrick.steuer@de.ibm.com>
Signed-off-by: NHarald Freudenberger <freude@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>