Make sure that all cpus in a book on a z10 appear as book siblings
and not as core siblings. This fixes some performance regressions that
appeared after the book scheduling domain got introduced.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

MSA3 and MSA4 instructions are only available under CONFIG_64BIT.
Bail out before using any of these instructions if the kernel is
running in 31 bit mode.
Signed-off-by: NJan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

In ESA mode STCKF is not defined even if the facility bit is enabled.
To prevent an illegal operation we must also check if we run a 64 bit kernel.
To make the check perform well add the STCKF bit to the machine flags.
Signed-off-by: NJan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

When the kernel is started in kdump mode, zfcpdump should not be
initialized because both dump methods can't be used at the same time.
Signed-off-by: NMichael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The kdump infrastructure is built on top of kexec. Therefore
CONFIG_KEXEC has to be enabled when CONFIG_CRASH_DUMP is selected.
Signed-off-by: NMichael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

'readelf -n' on the s390 vmlinux file generates lots of warnings about
corrupt notes. The reason is that the 'NOTE' program header has incorrect
file and memory sizes. The problem is that the section following the
NOTES section do not switch to a different phdr and they get added to
the NOTE program section. Add a dummy entry to the linker script that
switches to the data phdr before the start of the RODATA section.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Ignore completion interrupts if the initial interrupt hasn't been
received and the addressed task is not running. This case can only
happen if leftover (pending) completion interrupt gets delivered
which wasn't removed with the PFAULT CANCEL operation during cpu
hotplug.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The pgste_update_all / pgste_update_young and pgste_set_pte need to
check if the pte entry contains a valid page address before the storage
key can be accessed. In addition pgste_set_pte needs to set the access
key and fetch protection bit of the new pte entry, not the old entry.
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 avoids duplicating the function in every arch gup_fast.
Signed-off-by: NAndrea Arcangeli <aarcange@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <jweiner@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

s390 didn't return 0 in that case, if it's rolling back the *nr pointer it
should also return zero to avoid adding pages to the array at the wrong
offset.
Signed-off-by: NAndrea Arcangeli <aarcange@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <jweiner@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Up to this point the code assumed old refcounting for hugepages (pre-thp).
This updates the code directly to the thp mapcount tail page refcounting.
Signed-off-by: NAndrea Arcangeli <aarcange@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <jweiner@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Replace remaining direct i_nlink updates with a new set_nlink()
updater function.
Signed-off-by: NMiklos Szeredi <mszeredi@suse.cz>
Tested-by: NToshiyuki Okajima <toshi.okajima@jp.fujitsu.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Replace direct i_nlink updates with the respective updater function
(inc_nlink, drop_nlink, clear_nlink, inode_dec_link_count).
Signed-off-by: NMiklos Szeredi <mszeredi@suse.cz>

alloc_inode() initializes i_nlink to 1.  Remove unnecessary
re-initialization.
Signed-off-by: NMiklos Szeredi <mszeredi@suse.cz>
CC: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Fix several compile errors on s390 caused by splitting module.h.

Some include additions [e.g. qdio_setup.c, zfcp_qdio.c] are in
anticipation of pending changes queued for s390 that increase
the modular use footprint.

[PG: added additional obvious changes since Heiko's original patch]
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

Currently it can happen that the pre-allocated ELF header contains a wrong
memory map which would result in errors when copying /proc/vmcore.
In order to still get a valid vmcore, we (temporarily) disable the error
checking in copy_oldmem_page(). This will then produce zero pages for those
memory regions.
Signed-off-by: NMichael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

We use both the external call and emergency call IPIs to signal remote
cpus. Therefore it makes sense to account them differently withing
/proc/irqstats so we actually know what happened.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Fix this compiler error for !CONFIG_SMP:

  CC      arch/s390/mm/pgtable.o
arch/s390/mm/pgtable.c: In function ‘gmap_flush_tlb’:
arch/s390/mm/pgtable.c:202:3: error: implicit declaration of function ‘__tlb_flush_global’ [-Werror=implicit-function-declaration]
cc1: some warnings being treated as errors
Signed-off-by: NJan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Use __force to quiet sparse warnings about user address space.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Fix three sparse warnings in math-emu / sysinfo:

arch/s390/kernel/sysinfo.c:448:17: error: return expression in void function
arch/s390/kernel/sysinfo.c:445:25: warning: shift too big (32) for type unsigned int
arch/s390/kernel/sysinfo.c:445:25: warning: shift too big (32) for type unsigned int
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Add prototypes and includes for functions used in different modules.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Fix prototype of some functions in arch/s390/oprofile to avoid non-ANSI
warnings from sparse.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Make functions and data static to avoid sparse warnings.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Remove unnecessary code to avoid false positives from sparse, e.g.

arch/s390/kernel/compat_signal.c:221:61: warning: invalid access past the end of 'set32' (8 8)
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Add get_clock_fast() which uses the slightly faster stckf if available.
If stckf is not available fall back to stck, which has the same width.
Signed-off-by: NJan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Linux on System z uses a ballooner based on diagnose 0x10. (aka as
collaborative memory management). This patch implements diagnose
0x10 on the guest address space.
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

gmap_fault needs to walk the guest page table. However, parts of
that may change if some other thread does munmap. In that case
gmap_unmap_notifier will also unmap the corresponding parts from
the guest page table. We need to take mmap_sem in order to serialize
these operations.
do_exception now calls __gmap_fault with mmap_sem held which does
not get exported to modules. The exported function, which is called
from KVM, now takes mmap_sem.
Reported-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NCarsten Otte <cotte@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

This introduces locking via mm->page_table_lock to protect
the rmap list for guest mappings from being corrupted by concurrent
operations.
Signed-off-by: NCarsten Otte <cotte@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Fix possible deadlock reported by lockdep:
qemu-system-s39/2963 is trying to acquire lock:
(&mm->mmap_sem){++++++}, at: gmap_alloc_table+0x9c/0x120
but task is already holding lock:
(&mm->mmap_sem){++++++}, at: gmap_map_segment+0xa6/0x27c

Actually gmap_alloc_table is the only called in gmap_map_segment with
mmap_sem held, thus it's safe to simply remove the inner lock.
Signed-off-by: NCarsten Otte <cotte@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

On sie_fault we need to switch back to user ASCE. Otherwise we get
interresting effects when exiting to "userspace" while the guest
space is still active.
Signed-off-by: NCarsten Otte <cotte@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Use a sigp sense running to decide which signal processor order to use
for an ipi. If the target cpu is running use external call, if the target
cpu is not running use emergency signal.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Add support for CHSC I/O interrupt statistics in /proc/interrupts.
Signed-off-by: NSebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The user space program can change its addressing mode between the
24-bit, 31-bit and the 64-bit mode if the kernel is 64 bit. Currently
the kernel always forces the standard amode on signal delivery and
signal return and on ptrace: 64-bit for a 64-bit process, 31-bit for
a compat process and 31-bit kernels. Change the signal and ptrace code
to allow the full range of addressing modes. Signal handlers are
run in the standard addressing mode for the process.

One caveat is that even an 31-bit compat process can switch to the
64-bit mode. The next signal will switch back into the 31-bit mode
and there is no room in the 31-bit compat signal frame to store the
information that the program came from the 64-bit mode.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Split out addressing mode bits from PSW_BASE_BITS, rename PSW_BASE_BITS
to PSW_MASK_BASE, get rid of psw_user32_bits, remove unused function
enabled_wait(), introduce PSW_MASK_USER, and drop PSW_MASK_MERGE macros.
Change psw_kernel_bits / psw_user_bits to contain only the bits that
are always set in the respective mode.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Add an explicit TIF_SYSCALL bit that indicates if a task is inside
a system call. The svc_code in the pt_regs structure is now only
valid if TIF_SYSCALL is set. With this definition TIF_RESTART_SVC
can be replaced with TIF_SYSCALL. Overall do_signal is a bit more
readable and it saves a few lines of code.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

An instruction with an address right below the adress limit for the
current addressing mode will wrap. The instruction restart logic in
the protection fault handler and the signal code need to follow the
wrapping rules to find the correct instruction address.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

For a ERESTARTNOHAND/ERESTARTSYS/ERESTARTNOINTR restarting system call
do_signal will prepare the restart of the system call with a rewind of
the PSW before calling get_signal_to_deliver (where the debugger might
take control). For A ERESTART_RESTARTBLOCK restarting system call
do_signal will set -EINTR as return code.
There are two issues with this approach:
1) strace never sees ERESTARTNOHAND, ERESTARTSYS, ERESTARTNOINTR or
   ERESTART_RESTARTBLOCK as the rewinding already took place or the
   return code has been changed to -EINTR
2) if get_signal_to_deliver does not return with a signal to deliver
   the restart via the repeat of the svc instruction is left in place.
   This opens a race if another signal is made pending before the
   system call instruction can be reexecuted. The original system call
   will be restarted even if the second signal would have ended the
   system call with -EINTR.

These two issues can be solved by dropping the early rewind of the
system call before get_signal_to_deliver has been called and by using
the TIF_RESTART_SVC magic to do the restart if no signal has to be
delivered. The only situation where the system call restart via the
repeat of the svc instruction is appropriate is when a SA_RESTART
signal is delivered to user space.

Unfortunately this breaks inferior calls by the debugger again. The
system call number and the length of the system call instruction is
lost over the inferior call and user space will see ERESTARTNOHAND/
ERESTARTSYS/ERESTARTNOINTR/ERESTART_RESTARTBLOCK. To correct this a
new ptrace interface is added to save/restore the system call number
and system call instruction length.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Switching on the DEVTMPFS kernel option helpes to maintain a /dev
file system early in the boot process, especially, in limited
environments.
Signed-off-by: NHendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Remove the save_area_64 field from the 0xe00 - 0xf00 area in the lowcore.
Use a free slot in the save_area array instead.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>