Add four more defconfigs which we maintained outside of
the kernel tree for no good reason.
Inside of the kernel tree they can be easily used:

make whatever_defconfig

"make help" shows the available defconfigs.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Optimize this_cpu_* functions for 64 bit by making use of new instructions
that came with the interlocked-access facility 1 (load-and-*) and the
general-instructions-extension facility (asi, agsi).
That way we get rid of the compare-and-swap loop in most cases.
Code size reduction (defconfig, -march=z196): 11,555 bytes.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Remove the special cases for the this_cpu_* functions for 32 bit
in order to make it easier to add additional code for 64 bit.
32 bit will use the generic implementation.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Make psw32_user_bits a constant value again.
This is a leftover of the code which allowed to run the kernel either
in primary or home space which got removed with 9a905662 "s390/uaccess:
always run the kernel in home space".
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Fix the following bugs:
- When returning from a signal the signal handler copies the saved psw mask
  from user space and uses parts of it. Especially it restores the RI bit
  unconditionally. If however the machine doesn't support RI, or RI is
  disabled for the task, the last lpswe instruction which returns to user
  space will generate a specification exception.
  To fix this check if the RI bit is allowed to be set and kill the task
  if not.
- In the compat mode signal handler code the RI bit of the psw mask gets
  propagated to the mask of the return psw: if user space enables RI in the
  signal handler, RI will also be enabled after the signal handler is
  finished.
  This is a different behaviour than with 64 bit tasks. So change this to
  match the 64 bit semantics, which restores the original RI bit value.
- Fix similar oddities within the ptrace code as well.
Reviewed-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 FPC_VALID_MASK has been used to check the validity of the value
to be loaded into the floating-point-control register. With the
introduction of the floating-point extension facility and the
decimal-floating-point additional bits have been defined which need
to be checked in a non straight forward way. So far these bits have
been ignored which can cause an incorrect results for decimal-
floating-point operations, e.g. an incorrect rounding mode to be
set after signal return.

The static check with the FPC_VALID_MASK is replaced with a trial
load of the floating-point-control value, see test_fp_ctl.

In addition an information leak with the padding word between the
floating-point-control word and the floating-point registers in
the s390_fp_regs is fixed.
Reported-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

There is a debugging leftover from git commit 4d334fd1
"s390/3270: asynchronous size sensing" in raw3270_reset_device_cb.
Under z/VM the diagnose 0x210 can be used to find the correct
size of the 3270 terminal.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

If a machine has no hardware support for the xts-aes or ctr-aes algorithms
they are not registered in aes_s390_init. But aes_s390_fini unconditionally
unregisters the algorithms which causes crypto_remove_alg to crash.
Add two flag variables to remember if xts-aes and ctr-aes have been added.
Signed-off-by: NIngo Tuchscherer <ingo.tuchscherer@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Make smatch happy and remove this warning:

drivers/s390/char/raw3270.c:347 raw3270_irq() error: we previously
 assumed 'rq' could be null (see line 342)
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

This patch fixes the following smatch warning:
monwrite_diag() error: strcpy() '"LNXAPPL"' too large for 'id.prod_nr'
(8 vs 7)
Using strcpy() is wrong, because it also copies the terminating null
byte, but in this case the extra copied null byte will be overwritten
right after the strcpy(), so there is no real problem here.
Use strncpy() to fix the warning.
Signed-off-by: NGerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Just change the type of "len" to unsigned int so the compiler can prove
that we don't have a buffer overflow (and generates less code).
We get rid of these:

In function 'copy_from_user',
    inlined from 'appldata_interval_handler' at
    arch/s390/appldata/appldata_base.c:265:
      uaccess.h:303: warning: call to 'copy_from_user_overflow' declared
      with attribute warning: copy_from_user() buffer size is not provably
      correct
In function 'copy_from_user',
    inlined from 'appldata_timer_handler' at
    arch/s390/appldata/appldata_base.c:225:
      uaccess.h:303: warning: call to 'copy_from_user_overflow' declared
      with attribute warning: copy_from_user() buffer size is not provably
      correct
In function 'copy_from_user',
    inlined from 'appldata_generic_handler' at
    arch/s390/appldata/appldata_base.c:333:
      uaccess.h:303: warning: call to 'copy_from_user_overflow' declared
      with attribute warning: copy_from_user() buffer size is not provably
      correct
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Get rid of these two warnings:

In function 'copy_from_user',
    inlined from 'cmm_timeout_handler' at arch/s390/mm/cmm.c:310:
      uaccess.h:303: warning: call to 'copy_from_user_overflow' declared
      with attribute warning: copy_from_user() buffer size is not provably
      correct
In function 'copy_from_user',
    inlined from 'cmm_pages_handler' at arch/s390/mm/cmm.c:270:
      uaccess.h:303: warning: call to 'copy_from_user_overflow' declared
      with attribute warning: copy_from_user() buffer size is not provably
      correct

Change the "len" type to unsigned int, so we can make sure that there is no
buffer overflow. This also generates less code.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Get rid of this one:

arch/s390/kernel/cache.c: In function 'cache_build_info':
arch/s390/kernel/cache.c:144: warning: 'private' may be used uninitialized
in this function
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Instead of returnin the number of bytes not copied and/or -EFAULT let the
signal handler helper functions always return -EFAULT if a user space
access failed.
This doesn't fix a bug in the current code, but makes is harder to get it
wrong in the future.
Also "smatch" won't complain anymore about the fact that the number of
remaining bytes gets returned instead of -EFAULT.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

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

Missing parenthesis may cause problems when using the defines
together with operations of higher precedence.
Signed-off-by: NPeter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Currently zfpcdump can only collect registers for up to CONFIG_NR_CPUS
CPUss. This dependency is not necessary. So remove it by dynamically
allocating the save area array.
Signed-off-by: NMichael Holzheu <holzheu@linux.vnet.ibm.com>
Reviewed-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Steven Rostedt noted that s390 is the only architecture which calls
ftrace_push_return_trace() before ftrace_graph_entry() and therefore has
the small advantage that trace.depth gets initialized automatically.

However this small advantage isn't worth the difference and possible subtle
breakage that may result from this.
So change s390 to have the same function call order like all other
architectures: first ftrace_graph_entry(), then ftrace_push_return_trace()
Reported-by: NSteven Rostedt <rostedt@goodmis.org>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Get rid of this compile warning:

arch/s390/kernel/crash_dump.c: In function 'copy_from_realmem':
arch/s390/kernel/crash_dump.c:48:6: warning: unused variable 'rc'
[-Wunused-variable]
  int rc;
      ^
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The type of 'v->counter' is always 'int', and related inline assembly
code also process 'int', so use 'unsigned int' instead of 'unsigned
long' for the 'mask'.
Signed-off-by: NChen Gang <gang.chen@asianux.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

If [__]get_user_pages_fast() gets called with nr_pages == 0, the current
code would walk the page tables and pin as many pages until the first
invalid pte (or the kernel crashed while writing struct page pointers to
the pages array).
So let's handle at least the nr_pages == 0 case correctly and exit early.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Just call __get_user_pages_fast() from get_user_pages_fast() like powerpc.
This saves a lot of duplicated code.
Reviewed-by: NGerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

With dirty and referenced bits implemented in software it is unnecessary
to initialize the storage key for every page. With this patch not a single
storage key operation is done for a system that does not use KVM.
For KVM set_pte_at/pgste_set_key will do the initialization for the guest
view of the storage key when the mapping for the page is established in
the host.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The prolog of functions generated by the bpf jit compiler uses an
instruction sequence with an "ahi" instruction to create stack space
instead of using an "aghi" instruction. Using the 32-bit "ahi" is not
wrong as the stack we are operating on is an order-4 allocation which
is always aligned to 16KB. But it is more consistent to use an "aghi"
as the stack pointer is a 64-bit value.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

- turn some macros into functions
- merge two almost identical versions for 32/64 bit
- add BUILD_BUG_ON() check to make sure the passed in array is large enough
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

When quiescing an eadm subchannel make sure that outstanding IO is
cleared and potential timeout handlers are canceled.
Reviewed-by: NPeter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: NSebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Implement architecture-specific functionality when a PCI device is
doing a hibernate transition.
Signed-off-by: NSebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Simplify the uaccess code by removing the user_mode=home option.
The kernel will now always run in the home space mode.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

find_first_bit_left() and friends have nothing to do with the normal
LSB0 bit numbering for big endian machines used in Linux (least
significant bit has bit number 0).
Instead they use MSB0 bit numbering, where the most signficant bit has
bit number 0. So rename find_first_bit_left() and friends to
find_first_bit_inv(), to avoid any confusion.
Also provide inv versions of set_bit, clear_bit and test_bit.

This also removes the confusing use of e.g. set_bit() in airq.c which
uses a "be_to_le" bit number conversion, which could imply that instead
set_bit_le() could be used. But that is entirely wrong since the _le
bitops variant uses yet another bit numbering scheme.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Since z9 109 we have the flogr instruction which can be used to implement
optimized versions of __ffs, ffs, __fls, fls and fls64.
So implement and use them, instead of the generic variants.
This reduces the size of the kernel image (defconfig, -march=z9-109)
by 19,648 bytes.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Just like all other architectures we should use out-of-line find bit
operations, since the inline variant bloat the size of the kernel image.
And also like all other architecures we should only supply optimized
variants of the __ffs, ffs, etc. primitives.

Therefore this patch removes the inlined s390 find bit functions and uses
the generic out-of-line variants instead.

The optimization of the primitives follows with the next patch.

With this patch also the functions find_first_bit_left() and
find_next_bit_left() have been reimplemented, since logically, they are
nothing else but a find_first_bit()/find_next_bit() implementation that
use an inverted __fls() instead of __ffs().
Also the restriction that these functions only work on machines which
support the "flogr" instruction is gone now.

This reduces the size of the kernel image (defconfig, -march=z9-109)
by 144,482 bytes.
Alone the size of the function build_sched_domains() gets reduced from
7 KB to 3,5 KB.

We also git rid of unused functions like find_first_bit_le()...
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Refactor direct debug level comparisons with the (internal) s390db->level
member.  Use the debug_level_enabled() function instead.
Signed-off-by: NHendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Add the debug_level_enabled() function to check if debug events for
a particular level would be logged.  This might help to save cycles
for debug events that require additional information collection.
Signed-off-by: NHendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Since zEC12 we have the interlocked-access facility 2 which allows to
use the instructions ni/oi/xi to update a single byte in storage with
compare-and-swap semantics.
So change set_bit(), clear_bit() and change_bit() to generate such code
instead of a compare-and-swap loop (or using the load-and-* instruction
family), if possible.
This reduces the text segment by yet another 8KB (defconfig).

Alternatively the long displacement variants niy/oiy/xiy could have
been used, but the extended displacement field is usually not needed
and therefore would only increase the size of the text segment again.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Remove CONFIG_SMP from bitops code. This reduces the C code significantly
but also generates better code for the SMP case.

This means that for !CONFIG_SMP set_bit() and friends now also have
compare and swap semantics (read: more code). However nobody really cares
for !CONFIG_SMP and this is the trade-off to simplify the SMP code which we
do care about.

The non-atomic bitops like __set_bit() now generate also better code
because the old code did not have a __builtin_contant_p() check for the
CONFIG_SMP case and therefore always generated the inline assembly variant.
However the inline assemblies for the non-atomic case now got completely
removed since gcc can produce better code, which accesses less memory
operands.

test_bit() got also a bit simplified since it did have a
__builtin_constant_p() check, however two identical code pathes for each
case (written differently).

In result this mainly reduces the to be maintained code but is not very
relevant for code generation, since there are not many non-atomic bitops
usages that we care about.
(code reduction defconfig kernel image before/after: 560 bytes).
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

- add a typecheck to the defines to make sure they operate on an atomic_t
- simplify inline assembly constraints
- keep variable names common between functions
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

If the interlocked-access facility 1 is available we can use the asi
and agsi instructions for interlocked updates if the to be added
value is a contanst and small (in the range of -128..127).
asi and agsi do not not return the old or new value, therefore these
instructions can only be used for atomic_(add|sub|inc|dec)[64].
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

get_inbound_buffer_frontier() makes use of the return value of atomic_sub()
which shouldn't work, since atomic_sub() is supposed to return void.
This only works on s390 because atomic_sub() gets mapped to atomic_sub_return()
with a define without changing it's return value to void.

So use atomic_sub_return() instead of atomic_sub() in qeth code before fixing
atomic ops.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Since we have an in-kernel disassembler we can make sure that
there won't be any kprobes set on random data.
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>