When we use the iommu_area_alloc helper to get dma addresses
we specify the boundary_size parameter but not the offset (called
shift in this context).

As long as the offset (start_dma) is a multiple of the boundary
we're ok (on current machines start_dma always seems to be 4GB).

Don't leave this to chance and specify the offset for iommu_area_alloc.
Signed-off-by: NSebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: NGerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

We don't have an architectural guarantee on the value of
the dma offset but rely on it to be at least page aligned.
Enforce page alignemt of start_dma.
Signed-off-by: NSebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: NGerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Use dynamically allocated irq descriptors on s390 which allows
us to get rid of the s390 specific config option PCI_NR_MSI and
exploit more MSI interrupts. Also the size of the kernel image
is reduced by 131K (using performance_defconfig).
Signed-off-by: NSebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

When s390 traces with hex_ascii or sprintf view are
extracted and sorted, use the sort option -s (stable)
to avoid multiple lines with the same time stamp being
sorted using the rest of the line as secondary key.
Signed-off-by: NThomas Richter <tmricht@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Small cleanup patch to use the shorter __section macro everywhere.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

On s390 __ro_after_init is currently mapped to __read_mostly which
means that data marked as __ro_after_init will not be protected.

Reason for this is that the common code __ro_after_init implementation
is x86 centric: the ro_after_init data section was added to rodata,
since x86 enables write protection to kernel text and rodata very
late. On s390 we have write protection for these sections enabled with
the initial page tables. So adding the ro_after_init data section to
rodata does not work on s390.

In order to make __ro_after_init work properly on s390 move the
ro_after_init data, right behind rodata. Unlike the rodata section it
will be marked read-only later after all init calls happened.

This s390 specific implementation adds new __start_ro_after_init and
__end_ro_after_init labels. Everything in between will be marked
read-only after the init calls happened. In addition to the
__ro_after_init data move also the exception table there, since from a
practical point of view it fits the __ro_after_init requirements.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

commit c74ba8b3 ("arch: Introduce post-init read-only memory")
introduced the __ro_after_init attribute which allows to add variables
to the ro_after_init data section.

This new section was added to rodata, even though it contains writable
data. This in turn causes problems on architectures which mark the
page table entries read-only that point to rodata very early.

This patch allows architectures to implement an own handling of the
.data..ro_after_init section.
Usually that would be:
- mark the rodata section read-only very early
- mark the ro_after_init section read-only within mark_rodata_ro
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

ptep_flush_lazy and pmdp_flush_lazy use mm->context.attach_count to
decide between a lazy TLB flush vs an immediate TLB flush. The field
contains two 16-bit counters, the number of CPUs that have the mm
attached and can create TLB entries for it and the number of CPUs in
the middle of a page table update.

The __tlb_flush_asce, ptep_flush_direct and pmdp_flush_direct functions
use the attach counter and a mask check with mm_cpumask(mm) to decide
between a local flush local of the current CPU and a global flush.

For all these functions the decision between lazy vs immediate and
local vs global TLB flush can be based on CPU masks. There are two
masks:  the mm->context.cpu_attach_mask with the CPUs that are actively
using the mm, and the mm_cpumask(mm) with the CPUs that have used the
mm since the last full flush. The decision between lazy vs immediate
flush is based on the mm->context.cpu_attach_mask, to decide between
local vs global flush the mm_cpumask(mm) is used.

With this patch all checks will use the CPU masks, the old counter
mm->context.attach_count with its two 16-bit values is turned into a
single counter mm->context.flush_count that keeps track of the number
of CPUs with incomplete page table updates. The sole user of this
counter is finish_arch_post_lock_switch() which waits for the end of
all page table updates.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The bitmap_equal function has optimized code for small bitmaps with less
than BITS_PER_LONG bits. For larger bitmaps the out-of-line function
__bitmap_equal is called.

For a constant number of bits divisible by BITS_PER_LONG the memcmp
function can be used. For s390 gcc knows how to optimize this function,
memcmp calls with up to 256 bytes / 2048 bits are translated into a
single instruction.
Reviewed-by: NDavid Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The vunmap_pte_range() function calls ptep_get_and_clear() without any
locking. ptep_get_and_clear() uses ptep_xchg_lazy()/ptep_flush_direct()
for the page table update. ptep_flush_direct requires that preemption
is disabled, but without any locking this is not the case. If the kernel
preempts the task while the attach_counter is increased an endless loop
in finish_arch_post_lock_switch() will occur the next time the task is
scheduled.

Add explicit preempt_disable()/preempt_enable() calls to the relevant
functions in arch/s390/mm/pgtable.c.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The External-Time-Reference (ETR) clock synchronization interface has
been superseded by Server-Time-Protocol (STP). Remove the outdated
ETR interface.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The PTFF instruction can be used to retrieve information about UTC
including the current number of leap seconds. Use this value to
convert the coordinated server time value of the TOD clock to a
proper UTC timestamp to initialize the system time. Without this
correction the system time will be off by the number of leap seonds
until it has been corrected via NTP.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

It is possible to specify a user offset for the TOD clock, e.g. +2 hours.
The TOD clock will carry this offset even if the clock is synchronized
with STP. This makes the time stamps acquired with get_sync_clock()
useless as another LPAR migth use a different TOD offset.

Use the PTFF instrution to get the TOD epoch difference and subtract
it from the TOD clock value to get a physical timestamp. As the epoch
difference contains the sync check delta as well the LPAR offset value
to the physical clock needs to be refreshed after each clock
synchronization.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The PTFF instruction is not a function of ETR, rename and move the
PTFF definitions from etr.h to timex.h.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The sync clock operation of the channel subsystem call for STP delivers
the TOD clock difference as a result. Use this TOD clock difference
instead of the difference between the TOD timestamps before and after
the sync clock operation.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Reducing the size of reserved memory for the crash kernel will result
in an immediate crash on s390. Reason for that is that we do not
create struct pages for memory that is reserved. If that memory is
freed any access to struct pages which correspond to this memory will
result in invalid memory accesses and a kernel panic.

Fix this by properly creating struct pages when the system gets
initialized. Change the code also to make use of set_memory_ro() and
set_memory_rw() so page tables will be split if required.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Implement an s390 version of the weak crash_free_reserved_phys_range
function. This allows us to update the size of the reserved crash
kernel memory if it will be resized.

This was previously done with a call to crash_unmap_reserved_pages
from crash_shrink_memory which was removed with ("s390/kexec:
consolidate crash_map/unmap_reserved_pages() and
arch_kexec_protect(unprotect)_crashkres()")

Fixes: 7a0058ec ("s390/kexec: consolidate crash_map/unmap_reserved_pages() and arch_kexec_protect(unprotect)_crashkres()")
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The segment/region table that is part of the kernel image must be
properly aligned to 16k in order to make the crdte inline assembly
work.
Otherwise it will calculate a wrong segment/region table start address
and access incorrect memory locations if the swapper_pg_dir is not
aligned to 16k.

Therefore define BSS_FIRST_SECTIONS in order to put the swapper_pg_dir
at the beginning of the bss section and also align the bss section to
16k just like other architectures did.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Lets provide the basic machine information for dump_stack on
s390. This enables the "Hardware name:" line and results in
output like

[...]
Oops: 0004 ilc:2 [#1] SMP
Modules linked in:
CPU: 1 PID: 74 Comm: sh Not tainted 4.5.0+ #205
Hardware name: IBM              2964 NC9              704	(KVM)
[...]
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Acked-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Signed-off-by: NDaniel van Gerpen <daniel@vangerpen.de>
Acked-by: NPeter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Show the dynamic and static cpu mhz of each cpu. Since these values
are per cpu this requires a fundamental extension of the format of
/proc/cpuinfo.

Historically we had only a single line per cpu and a summary at the
top of the file. This format is hardly extendible if we want to add
more per cpu information.

Therefore this patch adds per cpu blocks at the end of /proc/cpuinfo:

cpu             : 0
cpu Mhz dynamic : 5504
cpu Mhz static  : 5504

cpu             : 1
cpu Mhz dynamic : 5504
cpu Mhz static  : 5504

cpu             : 2
cpu Mhz dynamic : 5504
cpu Mhz static  : 5504

cpu             : 3
cpu Mhz dynamic : 5504
cpu Mhz static  : 5504

Right now each block contains only the dynamic and static cpu mhz,
but it can be easily extended like on every other architecture.

This extension is supposed to be compatible with the old format.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: NSascha Silbe <silbe@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Change the code to print all the current output during the first
iteration. This is a preparation patch for the upcoming per cpu block
extension to /proc/cpuinfo.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Ensure that we always have __stringify().
Signed-off-by: NJason Baron <jbaron@akamai.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Add statistics that show how memory is mapped within the kernel
identity mapping. This is more or less the same like git
commit ce0c0e50 ("x86, generic: CPA add statistics about state
of direct mapping v4") for x86.

I also intentionally copied the lower case "k" within DirectMap4k vs
the upper case "M" and "G" within the two other lines. Let's have
consistent inconsistencies across architectures.

The output of /proc/meminfo now contains these additional lines:

DirectMap4k:        2048 kB
DirectMap1M:     3991552 kB
DirectMap2G:     4194304 kB

The implementation on s390 is lockless unlike the x86 version, since I
assume changes to the kernel mapping are a very rare event. Therefore
it really doesn't matter if these statistics could potentially be
inconsistent if read while kernel pages tables are being changed.
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>

For the kernel identity mapping map everything read-writeable and
subsequently call set_memory_ro() to make the ro section read-only.
This simplifies the code a lot.
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>

set_memory_ro() and set_memory_rw() currently only work on 4k
mappings, which is good enough for module code aka the vmalloc area.

However we stumbled already twice into the need to make this also work
on larger mappings:
- the ro after init patch set
- the crash kernel resize code

Therefore this patch implements automatic kernel page table splitting
if e.g. set_memory_ro() would be called on parts of a 2G mapping.
This works quite the same as the x86 code, but is much simpler.

In order to make this work and to be architecturally compliant we now
always use the csp, cspg or crdte instructions to replace valid page
table entries. This means that set_memory_ro() and set_memory_rw()
will be much more expensive than before. In order to avoid huge
latencies the code contains a couple of cond_resched() calls.

The current code only splits page tables, but does not merge them if
it would be possible.  The reason for this is that currently there is
no real life scenarion where this would really happen. All current use
cases that I know of only change access rights once during the life
time. If that should change we can still implement kernel page table
merging at a later time.
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>

Make pmd_wrprotect() and pmd_mkwrite() available independently from
CONFIG_TRANSPARENT_HUGEPAGE and CONFIG_HUGETLB_PAGE so these can be
used on the kernel mapping.

Also introduce a couple of pud helper functions, namely pud_pfn(),
pud_wrprotect(), pud_mkwrite(), pud_mkdirty() and pud_mkclean()
which only work on the kernel mapping.
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>

Always use PAGE_KERNEL when re-enabling pages within the kernel
mapping due to debug pagealloc. Without using this pgprot value
pte_mkwrite() and pte_wrprotect() won't work on such mappings after an
unmap -> map cycle anymore.
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>

Use pte_clear() instead of open-coding it.
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>

_REGION3_ENTRY_RO is a duplicate of _REGION_ENTRY_PROTECT.
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>

Instead of open-coded SEGMENT_KERNEL and REGION3_KERNEL assignments use
defines.  Also to make e.g. pmd_wrprotect() work on the kernel mapping
a couple more flags must be set. Therefore add the missing flags also.

In order to make everything symmetrical this patch also adds software
dirty, young, read and write bits for region 3 table entries.
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>

Usually segment and region tables are 16k aligned due to the way the
buddy allocator works.  This is not true for the vmem code which only
asks for a 4k alignment. In order to be consistent enforce a 16k
alignment here as well.

This alignment will be assumed and therefore is required by the
pageattr code.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Acked-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

We have already two inline assemblies which make use of the csp
instruction. Since I need a third instance let's introduce a generic
inline assmebly which can be used by everyone.
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>

Use memdup_user_nul to duplicate a memory region from user-space
to kernel-space and terminate with a NULL, instead of open coding
using kmalloc + copy_from_user and explicitly NULL terminating.
Signed-off-by: NMuhammad Falak R Wani <falakreyaz@gmail.com>
[heiko.carstens@de.ibm.com: remove comment]
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

commit 1e133ab2 ("s390/mm: split arch/s390/mm/pgtable.c") factored
out the page table handling code from __gmap_zap and  __s390_reset_cmma
into ptep_zap_unused and added a simple flag that tells which one of the
function (reset or not) is to be made. This also changed the behaviour,
as it also zaps unused page table entries on reset.
Turns out that this is wrong as s390_reset_cmma uses the page walker,
which DOES NOT take the ptl lock.

The most simple fix is to not do the zapping part on reset (which uses
the walker)
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Fixes: 1e133ab2 ("s390/mm: split arch/s390/mm/pgtable.c")
Cc: stable@vger.kernel.org # 4.6+
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Pull thermal management fixes from Zhang Rui:

 - fix an ordering issue in cpu cooling that cooling device is
   registered before it's ready (freq_table being populated).
   (Lukasz Luba)

 - fix a missing comment update (Caesar Wang)

* 'for-rc' of git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux:
  thermal: add the note for set_trip_temp
  thermal: cpu_cooling: fix improper order during initialization

Pull block layer fixes from Jens Axboe:
 "A small collection of fixes for the current series.  This contains:

   - Two fixes for xen-blkfront, from Bob Liu.

   - A bug fix for NVMe, releasing only the specific resources we
     requested.

   - Fix for a debugfs flags entry for nbd, from Josef.

   - Plug fix from Omar, fixing up a case of code being switched between
     two functions.

   - A missing bio_put() for the new discard callers of
     submit_bio_wait(), fixing a regression causing a leak of the bio.
     From Shaun.

   - Improve dirty limit calculation precision in the writeback code,
     fixing a case where setting a limit lower than 1% of memory would
     end up being zero.  From Tejun"

* 'for-linus' of git://git.kernel.dk/linux-block:
  NVMe: Only release requested regions
  xen-blkfront: fix resume issues after a migration
  xen-blkfront: don't call talk_to_blkback when already connected to blkback
  nbd: pass the nbd pointer for flags debugfs
  block: missing bio_put following submit_bio_wait
  blk-mq: really fix plug list flushing for nomerge queues
  writeback: use higher precision calculation in domain_dirty_limits()

Pull GPIO fixes from Linus Walleij:
 "A new bunch of GPIO fixes for v4.7.

  This time I am very grateful that Ricardo Ribalda Delgado went in and
  fixed my stupid refcounting mistakes in the removal path for GPIO
  chips.  I had a feeling something was wrong here and so it was.  It
  exploded on OMAP and it fixes their problem.  Now it should be (more)
  solid.

  The rest i compilation, Kconfig and driver fixes.  Some tagged for
  stable.

  Summary:

   - Fix a NULL pointer dereference when we are searching the GPIO
     device list but one of the devices have been removed (struct
     gpio_chip pointer is NULL).

   - Fix unaligned reference counters: we were ending on +3 after all
     said and done.  It should be 0.  Remove an extraneous get_device(),
     and call cdev_del() followed by device_del() in gpiochip_remove()
     instead and the count goes to zero and calls the release() function
     properly.

   - Fix a compile warning due to a missing #include in the OF/device
     tree portions.

   - Select ANON_INODES for GPIOLIB, we're using that for our character
     device.  Some randconfig tests disclosed the problem.

   - Make sure the Zynq driver clock runs also without CONFIG_PM enabled

   - Fix an off-by-one error in the 104-DIO-48E driver

   - Fix warnings in bcm_kona_gpio_reset()"

* tag 'gpio-v4.7-3' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio:
  gpio: bcm-kona: fix bcm_kona_gpio_reset() warnings
  gpio: select ANON_INODES
  gpio: include <linux/io-mapping.h> in gpiolib-of
  gpiolib: Fix unaligned used of reference counters
  gpiolib: Fix NULL pointer deference
  gpio: zynq: initialize clock even without CONFIG_PM
  gpio: 104-dio-48e: Fix control port offset computation off-by-one error

Pull SCSI fixes from James Bottomley:
 "Two current fixes:

   - one affects Qemu CD ROM emulation, which stopped working after the
     updates in SCSI to require VPD pages from all conformant devices.

     Fix temporarily by blacklisting Qemu (we can relax later when they
     come into compliance).

   - The other is a fix to the optimal transfer size.  We set up a
     minefield for ourselves by being confused about whether the limits
     are in bytes or sectors (SCSI optimal is in blocks and the queue
     parameter is in bytes).

     This tries to fix the problem (wrong setting for queue limits
     max_sectors) and make the problem more obvious by introducing a
     wrapper function"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  sd: Fix rw_max for devices that report an optimal xfer size
  scsi: Add QEMU CD-ROM to VPD Inquiry Blacklist