The code in the various ptep_xxx functions has grown quite large,
consolidate them to four out-of-line functions:
  ptep_xchg_direct to exchange a pte with another with immediate flushing
  ptep_xchg_lazy to exchange a pte with another in a batched update
  ptep_modify_prot_start to begin a protection flags update
  ptep_modify_prot_commit to commit a protection flags update
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

Provide a user space interface to issue call logical-processor instructions.
Only selected CLP commands are allowed, enough to get the full overview of
the installed PCI functions.
Reviewed-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

Convert the uses of pr_warning to pr_warn so there are fewer
uses of the old pr_warning.

Miscellanea:

o Align arguments
o Coalesce formats
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

Convert dasd_device.private to be a void pointer to get
rid of a lot of explicit casts.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: Stefan Haberland <sth@linux.vnet.ibm.com>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

Prepare for new format checking function by renaming functions and
moving reusable code to separate functions:

- Move sanity checks into a new function and make it reusable.
- Move common format code to a new function called
  dasd_eckd_format_process_data.
- Create the generic function dasd_eckd_format_build_ccw_req, which
  itself will then decide what ccw request is being built according to
  the input data. (with upcoming functionality).
Signed-off-by: Jan Höppner <hoeppner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

Currently, dasd_format is calling the format logic of a DASD discipline
with PAV enabled. If that fails with an error code of -EAGAIN the value
of retries is decremented and the discipline function is called with PAV
turned off.

The loop is supposed to try this up to 255 times until success. However,
-EAGAIN can only occur once here and therefore the loop will never reach
the 255 retries.

So, replace the unnecessarily complicated loop logic and simply try again
without PAV enabled in case of an -EAGAIN error.
Signed-off-by: Jan Höppner <hoeppner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

- Make sure a calling function can rely on data in fdata by resetting to
  its initial values
- Move special treatment for track 0 and 1 to dasd_eckd_build_format
- Replace dangerous backward goto with a loop logic
- Add define for number that specifies the maximum amount of CCWs per
  request and is used for format_step calculation
- Remove unused variable
Signed-off-by: Jan Höppner <hoeppner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

git commit 26f15caa ("s390/cmpxchg: simplify cmpxchg_double")
removed support for cmpxchg_double for two consecutive four byte
values, for which it would generate a cds instruction.

However I forgot to remove the corresponding define in our percpu
header file, which means that this_cpu_cmpxchg_double would now
incorrectly generate a cdsg instruction if being used on a double four
byte location. Therefore remove the percpu define as well.

There is currently no user and therefore no bug fixed with
this. Obviously any such user could and should simply use cmpxchg.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

commit e22cf8ca ("s390/cpumf: rework program parameter setting
to detect guest samples") requires guest changes to get proper
guest/host. We can do better: We can use the primary asn value,
which is set on all Linux variants to compare this with the host
pp value.
We now have the following cases:
1. Guest using PP
host sample:  gpp == 0, asn == hpp --> host
guest sample: gpp != 0 --> guest
2. Guest not using PP
host sample:  gpp == 0, asn == hpp --> host
guest sample: gpp == 0, asn != hpp --> guest

As soon as the host no longer sets CR4, we must back out
this heuristics - let's add a comment in switch_to.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

We have two close to identical report_user_fault functions.
Add a parameter to one and get rid of the other one in order
to reduce code duplication.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

The double escape character sequence introduced with commit
272fa59c ("s390/dis: Fix handling of format specifiers") is not
necessary anymore since commit 561e1030 ("s390/dis: Fix printing
of the register numbers").

Instead this now generates an extra '%' character:

lg      %%r1,160(%%r11)

So fix this and basically revert 272fa59c.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

Git commit ab3f285f
"KVM: s390/mm: try a cow on read only pages for key ops"
added a fixup_user_fault to set_guest_storage_key force a copy on
write if the page is mapped read-only. This is supposed to fix the
problem of differing storage keys for shared mappings, e.g. the
empty_zero_page.
But if the storage key is set before the pte is mapped the storage
key update is done on the pgste. A later fault will happily map the
shared page with the key from the pgste.

Eventually git commit 2faee8ff
"s390/mm: prevent and break zero page mappings in case of storage keys"
fixed this problem for the empty_zero_page. The commit makes sure that
guests enabled for storage keys will not use the empty_zero_page at all.

As the call to fixup_user_fault in set_guest_storage_key depends on the
order of the storage key operation vs. the fault that maps the pte
it does not really fix anything. Just remove it.
Reviewed-by: Dominik Dingel <dingel@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

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

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

The comment describing the bit encoding for segment table entries
is incorrect in regard to the read and write bits. The segment
read bit is 0x0002 and write is 0x0001, not the other way around.
Reported-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

We have four different stack tracers of which three had bugs. So it's
time to merge them to a single stack tracer which allows to specify a
call back function which will be called for each step.

This patch changes behavior a bit:

- the "nosched" and "in_sched_functions" check within
  save_stack_trace_tsk did work only for the last stack frame within a
  context. Now it considers the check for each stack frame like it
  should.

- both the oprofile variant and the perf_events variant did save a
  return address twice if a zero back chain was detected, which
  indicates an interrupt frame. The new dump_trace function will call
  the oprofile and perf_events backends with the psw address that is
  contained within the corresponding pt_regs structure instead.

- the original show_trace and save_context_stack functions did already
  use the psw address of the pt_regs structure if a zero back chain
  was detected. However now we ignore the psw address if it is a user
  space address. After all we trace the kernel stack and not the user
  space stack. This way we also get rid of the garbage user space
  address in case of warnings and / or panic call traces.

So this should make life easier since now there is only one stack
tracer left which we can break.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

The first parameter of pgste_update_all is a pointer to a pte.
Simplify the code by passing the pte value.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

The correct lock order for LCU lock and cdev lock is to take the cdev
lock first and afterwards the LCU lock. This is caused by the fact
that LCU functions are called in an interrupt context with the cdev
lock implicitly hold by CIO.

To assure the right locking order but also be able to iterate over
devices in a LCU introduce a trylock block that can be called with
the device lock for one device hold and then takes the LCU lock and
try to lock all devices accounted to this LCU. Afterwards all devices
and the LCU itself are locked.
Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

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

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

Implement current_stack_pointer() helper function and use it
everywhere, instead of having several different inline assembly
variants.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Tested-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

Use the inversed "nosched" logic like all other architectures.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Tested-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

The change of the access rights for an address range in the kernel
address space is currently done with a loop of IPTE + a store of the
modified PTE. Between the IPTE and the store the PTE will be invalid,
this intermediate state can cause problems with concurrent accesses.

Consider a change of a kernel area from read-write to read-only, a
concurrent reader of that area should be fine but with the invalid
PTE it might get an unexpected exception.

Remove the IPTEs for each PTE and do a global flush after all PTEs
have been modified.
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

For each PCI function we need to maintain arch specific data in
struct zpci_dev which also contains a pointer to struct pci_dev.

When a function is registered or deregistered (which is triggered by PCI
common code) we need to adjust that pointer which could interfere with
the machine check handler (triggered by FW) using zpci_dev->pdev.

Since multiple instances of the same pdev could exist at a time this can't
be solved with locking.

Fix that by ditching the pdev pointer and use a bus walk to reach
struct pci_dev (only one instance of a pdev can be registered at the bus
at a time).
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

git commit 904818e2
"s390/kernel: introduce fpu-internal.h with fpu helper functions"
introduced the fpregs_store / fp_regs_load helper. These function
fail to save and restore the floating pointer control registers.

The effect is that the FPC is not correctly handled on signal
delivery and signal return.

Cc: stable@vger.kernel.org # 4.4
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

git commit 80703617
"s390: add support for vector extension"
broke 31-bit compat processes in regard to signal handling.

The restore_sigregs_ext32() function is used to restore the additional
elements from the user space signal frame. Among the additional elements
are the upper registers halves for 64-bit register support for 31-bit
processes. The copy_from_user that is used to retrieve the high-gprs
array from the user stack uses an incorrect length, 8 bytes instead of
64 bytes. This causes incorrect upper register halves to get loaded.

Cc: stable@vger.kernel.org # 3.8+
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

Pull x86 fixes from Ingo Molnar:
 "This is unusually large, partly due to the EFI fixes that prevent
  accidental deletion of EFI variables through efivarfs that may brick
  machines.  These fixes are somewhat involved to maintain compatibility
  with existing install methods and other usage modes, while trying to
  turn off the 'rm -rf' bricking vector.

  Other fixes are for large page ioremap()s and for non-temporal
  user-memcpy()s"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mm: Fix vmalloc_fault() to handle large pages properly
  hpet: Drop stale URLs
  x86/uaccess/64: Handle the caching of 4-byte nocache copies properly in __copy_user_nocache()
  x86/uaccess/64: Make the __copy_user_nocache() assembly code more readable
  lib/ucs2_string: Correct ucs2 -> utf8 conversion
  efi: Add pstore variables to the deletion whitelist
  efi: Make efivarfs entries immutable by default
  efi: Make our variable validation list include the guid
  efi: Do variable name validation tests in utf8
  efi: Use ucs2_as_utf8 in efivarfs instead of open coding a bad version
  lib/ucs2_string: Add ucs2 -> utf8 helper functions

Pull perf fixes from Ingo Molnar:
 "A handful of CPU hotplug related fixes"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/core: Plug potential memory leak in CPU_UP_PREPARE
  perf/core: Remove the bogus and dangerous CPU_DOWN_FAILED hotplug state
  perf/core: Remove bogus UP_CANCELED hotplug state
  perf/x86/amd/uncore: Plug reference leak

Pull powerpc fixes from Michael Ellerman:
 - Fix build error on 32-bit with checkpoint restart from Aneesh Kumar
 - Fix dedotify for binutils >= 2.26 from Andreas Schwab
 - Don't trace hcalls on offline CPUs from Denis Kirjanov
 - eeh: Fix stale cached primary bus from Gavin Shan
 - eeh: Fix stale PE primary bus from Gavin Shan
 - mm: Fix Multi hit ERAT cause by recent THP update from Aneesh Kumar K.V
 - ioda: Set "read" permission when "write" is set from Alexey Kardashevskiy

* tag 'powerpc-4.5-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/ioda: Set "read" permission when "write" is set
  powerpc/mm: Fix Multi hit ERAT cause by recent THP update
  powerpc/powernv: Fix stale PE primary bus
  powerpc/eeh: Fix stale cached primary bus
  powerpc/pseries: Don't trace hcalls on offline CPUs
  powerpc: Fix dedotify for binutils >= 2.26
  powerpc/book3s_32: Fix build error with checkpoint restart

Pull dmaengine fixes from Vinod Koul:
 "A few fixes for drivers, nothing major here.

  Fixes are: iotdma fix to restart channels, new ID for wildcat PCH,
  residue fix for edma, disable irq for non-cyclic in dw"

* tag 'dmaengine-fix-4.5-rc5' of git://git.infradead.org/users/vkoul/slave-dma:
  dmaengine: dw: disable BLOCK IRQs for non-cyclic xfer
  dmaengine: edma: fix residue race for cyclic
  dmaengine: dw: pci: add ID for WildcatPoint PCH
  dmaengine: IOATDMA: fix timer code that continues to restart channels during idle

Pull clk driver fixes from Stephen Boyd:
 "An assortment of vendor specific clk drivers fixes, most notably
  fallout from adding Tegra210 and rockchip rk3036/rk3368 drivers this
  cycle.

  There's also the random smattering of sparse/checker fixes, a build
  "fix" to get the Tango clk driver to compile because the Kconfig
  symbol was renamed after the fact, and a clk gpio fix for a patch
  mismerge"

* tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux: (28 commits)
  clk: gpio: Really allow an optional clock= DT property
  Revert "clk: qcom: Specify LE device endianness"
  clk: versatile: mask VCO bits before writing
  clk: tegra: super: Fix sparse warnings for functions not declared as static
  clk: tegra: Fix sparse warnings for functions not declared as static
  clk: tegra: Fix sparse warning for pll_m
  clk: tegra: Use definition for pll_u override bit
  clk: tegra: Fix warning caused by pll_u failing to lock
  clk: tegra: Fix clock sources for Tegra210 EMC
  clk: tegra: Add the APB2APE audio clock on Tegra210
  clk: tegra: Add missing of_node_put()
  clk: tegra: Fix PLLE SS coefficients
  clk: tegra: Fix typos around clearing PLLE bits during enable
  clk: tegra: Do not disable PLLE when under hardware control
  clk: tegra: Fix pllx dyn step calculation
  clk: tegra: pll: Fix potential sleeping-while-atomic
  clk: tegra: Fix the misnaming of nvenc from msenc
  clk: tegra: Fix naming of MISC registers
  clk: tango4: rename ARCH_TANGOX to ARCH_TANGO
  clk: scpi: Fix checking return value of platform_device_register_simple()
  ...

Pull more drm fixes from Dave Airlie:
 "Some more fixes trickled in:

  A bunch of VC4 ones since it's a pretty new driver not much chance of
  regressions, and it fixes GPU resets.

  Also one atomic fix, one set of fixes for a common bug in TTM cleanup,
  and one i915 hotplug fix"

* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux:
  drm/nouveau: use post-decrement in error handling
  drm/atomic: Allow for holes in connector state, v2.
  drm/i915: Fix hpd live status bits for g4x
  drm/vc4: Use runtime PM to power cycle the device when the GPU hangs.
  drm/vc4: Enable runtime PM.
  drm/vc4: Fix spurious GPU resets due to BO reuse.
  drm/vc4: Drop error message on seqno wait timeouts.
  drm/vc4: Fix -ERESTARTSYS error return from BO waits.
  drm/vc4: Return an ERR_PTR from BO creation instead of NULL.
  drm/vc4: Fix the clear color for the first tile rendered.
  drm/vc4: Validate that WAIT_BO padding is cleared.
  drm/radeon: use post-decrement in error handling
  drm/amdgpu: use post-decrement in error handling

In __request_region, if a conflict with a BUSY and MUXED resource is
detected, then the caller goes to sleep and waits for the resource to be
released.  A pointer on the conflicting resource is kept.  At wake-up
this pointer is used as a parent to retry to request the region.

A first problem is that this pointer might well be invalid (if for
example the conflicting resource have already been freed).  Another
problem is that the next call to __request_region() fails to detect a
remaining conflict.  The previously conflicting resource is passed as a
parameter and __request_region() will look for a conflict among the
children of this resource and not at the resource itself.  It is likely
to succeed anyway, even if there is still a conflict.

Instead, the parent of the conflicting resource should be passed to
__request_region().

As a fix, this patch doesn't update the parent resource pointer in the
case we have to wait for a muxed region right after.
Reported-and-tested-by: Vincent Pelletier <plr.vincent@gmail.com>
Signed-off-by: Simon Guinot <simon.guinot@sequanux.org>
Tested-by: Vincent Donnefort <vdonnefort@gmail.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull ext4 bugfixes from Ted Ts'o:
 "Miscellaneous ext4 bug fixes for v4.5"

* tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: fix crashes in dioread_nolock mode
  ext4: fix bh->b_state corruption
  ext4: fix memleak in ext4_readdir()
  ext4: remove unused parameter "newblock" in convert_initialized_extent()
  ext4: don't read blocks from disk after extents being swapped
  ext4: fix potential integer overflow
  ext4: add a line break for proc mb_groups display
  ext4: ioctl: fix erroneous return value
  ext4: fix scheduling in atomic on group checksum failure
  ext4 crypto: move context consistency check to ext4_file_open()
  ext4 crypto: revalidate dentry after adding or removing the key

Pull btrfs fix from Chris Mason:
 "My for-linus-4.5 branch has a btrfs DIO error passing fix.

  I know how much you love DIO, so I'm going to suggest against reading
  it.  We'll follow up with a patch to drop the error arg from
  dio_end_io in the next merge window."

* 'for-linus-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: fix direct IO requests not reporting IO error to user space

Merge fixes from Andrew Morton:
 "10 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  mm: slab: free kmem_cache_node after destroy sysfs file
  ipc/shm: handle removed segments gracefully in shm_mmap()
  MAINTAINERS: update Kselftest Framework mailing list
  devm_memremap_release(): fix memremap'd addr handling
  mm/hugetlb.c: fix incorrect proc nr_hugepages value
  mm, x86: fix pte_page() crash in gup_pte_range()
  fsnotify: turn fsnotify reaper thread into a workqueue job
  Revert "fsnotify: destroy marks with call_srcu instead of dedicated thread"
  mm: fix regression in remap_file_pages() emulation
  thp, dax: do not try to withdraw pgtable from non-anon VMA

Pull arm64 fixes from Will Deacon:
 "Here are some more arm64 fixes for 4.5.  This has mostly come from
  Yang Shi, who saw some issues under -rt that also affect mainline.
  The rest of it is pretty small, but still worth having.

  We've got an old issue outstanding with valid_user_regs which will
  likely wait until 4.6 (since it would really benefit from some time in
  -next) and another issue with kasan and idle which should be fixed
  next week.

  Apart from that, pretty quiet here (and still no sign of the THP issue
  reported on s390...)

  Summary:

   - Allow EFI stub to use strnlen(), which is required by recent libfdt

   - Avoid smp_processor_id() in preempt context during unwinding

   - Avoid false Kasan warnings during unwinding

   - Ensure early devices are picked up by the IOMMU DMA ops

   - Avoid rebuilding the kernel for the 'install' target

   - Run fixup handlers for alignment faults on userspace access"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: mm: allow the kernel to handle alignment faults on user accesses
  arm64: kbuild: make "make install" not depend on vmlinux
  arm64: dma-mapping: fix handling of devices registered before arch_initcall
  arm64/efi: Make strnlen() available to the EFI namespace
  arm/arm64: crypto: assure that ECB modes don't require an IV
  arm64: make irq_stack_ptr more robust
  arm64: debug: re-enable irqs before sending breakpoint SIGTRAP
  arm64: disable kasan when accessing frame->fp in unwind_frame

Pull s390 fixes from Martin Schwidefsky:
 "Several bug fixes:

   - There are four different stack tracers, and three of them have
     bugs.  For 4.5 the bugs are fixed and we prepare a cleanup patch
     for the next merge window.

   - Three bug fixes for the dasd driver in regard to parallel access
     volumes and the new max_dev_sectors block device queue limit

   - The irq restore optimization needs a fixup for memcpy_real

   - The diagnose trace code has a conflict with lockdep"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390/dasd: fix performance drop
  s390/maccess: reduce stnsm instructions
  s390/diag: avoid lockdep recursion
  s390/dasd: fix refcount for PAV reassignment
  s390/dasd: prevent incorrect length error under z/VM after PAV changes
  s390: fix DAT off memory access, e.g. on kdump
  s390/oprofile: fix address range for asynchronous stack
  s390/perf_event: fix address range for asynchronous stack
  s390/stacktrace: add save_stack_trace_regs()
  s390/stacktrace: save full stack traces
  s390/stacktrace: add missing end marker
  s390/stacktrace: fix address ranges for asynchronous and panic stack
  s390/stacktrace: fix save_stack_trace_tsk() for current task