Move the program interruption code and the translation exception identifier
to the pt_regs structure as 'int_code' and 'int_parm_long' and make the
first level interrupt handler in entry[64].S store the two values. That
makes it possible to drop 'prot_addr' and 'trap_no' from the thread_struct
and to reduce the number of arguments to a lot of functions. Finally
un-inline do_trap. Overall this saves 5812 bytes in the .text section of
the 64 bit kernel.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Remove last traces of our kerntypes patch which was always an addon
patch which never got upstream. Somehow a few bits got upstream
anyway.
Since kerntypes aren't used anymore and lcrash isn't maintained (for
s390 at least) remove the last traces of kerntypes that somehow went
upstream. Also remove the documentation that mentions lcrash.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Increase cpu topology change poll frequency if a change is anticipated.
Otherwise a user might be a bit confused to have to wait up to a minute
in order to see a change this should be visible immediatly.
However there is no guarantee that the change will happen during the
time frame the poll frequency is increased.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Another round of cleanup for entry[64].S, in particular the program check
handler looks more reasonable now. The code size for the 31 bit kernel
has been reduced by 616 byte and by 528 byte for the 64 bit version.
Even better the code is a bit faster as well.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Only add subdirectories of arch/s390 to kbuild if their respective
config option is selected.
Signed-off-by: NJan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

There is no reason for the cpu-measurement-facility host id constant to
reside in the lowcore where space is precious. Use an entry in the literal
pool in HANDLE_SIE_INTERCEPT and a stack slot in sie64a.
While we are at it replace the id -1 with 0 to indicate host execution.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Cleanup z10 topology handling. This adds some more code but hopefully
the result is more readable and easier to maintain.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

This patch disables the check for MACHINE_IS_VM when initializing the
pfault infrastructure. The code checks for successful completion of
diag 258 anyway, thus it's safe to try initialization on LPAR anyway.
This is needed to use pfault on kvm
Signed-off-by: NCarsten Otte <cotte@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Remove all ifdefs from topology code and also only compile it for the
CONFIG_SCHED_BOOK case. The new code selects SCHED_MC if SCHED_BOOK is
selected. SCHED_MC without SCHED_BOOK is not possible anymore.
Furthermore various sysfs attributes are not available anymore for the
!SCHED_BOOK case. In particular all attributes that correspond to
CPU polarization.
But since all real world kernels have SCHED_BOOK selected anyway this
doesn't matter too much.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Currently, when smp_switch_to_ipl_cpu() is done, the backchain in the dump
analysis tool crash looks like the following:

 #0 [1f746e70] __machine_kexec at 11dd92
 #1 [1f746eb8] smp_restart_cpu at 11820e
 #0 [00907eb0] cpu_idle at 10602e
 #1 [00907ef8] start_kernel at 979a08

It would be good to see the registers of the interrupted function.
To achieve this, the backchain on the new stack has to be set to zero.
This looks then like the following:

 #0 [1f746e70] __machine_kexec at 11dd8e
 #1 [1f746eb8] smp_restart_cpu at 11820a
 PSW:  0706000180000000 00000000005c6fe6 (vtime_stop_cpu+134)
 GPRS: 0000000000000000 00000000005c6fe6 0000000001ad0228 0000000001ad0248
       0000000000907f08 0000000001ad0b40 0000000000979344 0000000000000000
       00000000009c0000 00000000009c0010 00000000009ab024 0000000001ad0200
       0000000001ad0238 00000000005cc9d8 000000000010602e 0000000000907e68
 #0 [00907eb0] cpu_idle at 10602e
 #1 [00907ef8] start_kernel at 979a08

In addition to this, now also the correct PSW is stored in the pt_regs
structure that is located at the start of the panic stack.
Signed-off-by: NMichael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The kernel address space of a 64 bit kernel currently uses a three level
page table and the vmemmap array has a fixed address and a fixed maximum
size. A three level page table is good enough for systems with less than
3.8TB of memory, for bigger systems four page table levels need to be
used. Each page table level costs a bit of performance, use 3 levels for
normal systems and 4 levels only for the really big systems.
To avoid bloating sparse.o too much set MAX_PHYSMEM_BITS to 46 for a
maximum of 64TB of memory.
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>

This patch makes the create_mem_hole() function more readable and
fixes some minor bugs (e.g. off-by-one problems).
Signed-off-by: NMichael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

commit cc772456
    [S390] fix list corruption in gmap reverse mapping

added a potential dead lock:

BUG: sleeping function called from invalid context at mm/page_alloc.c:2260
in_atomic(): 1, irqs_disabled(): 0, pid: 1108, name: qemu-system-s39
3 locks held by qemu-system-s39/1108:
 #0:  (&kvm->slots_lock){+.+.+.}, at: [<000003e004866542>] kvm_set_memory_region+0x3a/0x6c [kvm]
 #1:  (&mm->mmap_sem){++++++}, at: [<0000000000123790>] gmap_map_segment+0x9c/0x298
 #2:  (&(&mm->page_table_lock)->rlock){+.+.+.}, at: [<00000000001237a8>] gmap_map_segment+0xb4/0x298
CPU: 0 Not tainted 3.1.3 #45
Process qemu-system-s39 (pid: 1108, task: 00000004f8b3cb30, ksp: 00000004fd5978d0)
00000004fd5979a0 00000004fd597920 0000000000000002 0000000000000000
       00000004fd5979c0 00000004fd597938 00000004fd597938 0000000000617e96
       0000000000000000 00000004f8b3cf58 0000000000000000 0000000000000000
       000000000000000d 000000000000000c 00000004fd597988 0000000000000000
       0000000000000000 0000000000100a18 00000004fd597920 00000004fd597960
Call Trace:
([<0000000000100926>] show_trace+0xee/0x144)
 [<0000000000131f3a>] __might_sleep+0x12a/0x158
 [<0000000000217fb4>] __alloc_pages_nodemask+0x224/0xadc
 [<0000000000123086>] gmap_alloc_table+0x46/0x114
 [<000000000012395c>] gmap_map_segment+0x268/0x298
 [<000003e00486b014>] kvm_arch_commit_memory_region+0x44/0x6c [kvm]
 [<000003e004866414>] __kvm_set_memory_region+0x3b0/0x4a4 [kvm]
 [<000003e004866554>] kvm_set_memory_region+0x4c/0x6c [kvm]
 [<000003e004867c7a>] kvm_vm_ioctl+0x14a/0x314 [kvm]
 [<0000000000292100>] do_vfs_ioctl+0x94/0x588
 [<0000000000292688>] SyS_ioctl+0x94/0xac
 [<000000000061e124>] sysc_noemu+0x22/0x28
 [<000003fffcd5e7ca>] 0x3fffcd5e7ca
3 locks held by qemu-system-s39/1108:
 #0:  (&kvm->slots_lock){+.+.+.}, at: [<000003e004866542>] kvm_set_memory_region+0x3a/0x6c [kvm]
 #1:  (&mm->mmap_sem){++++++}, at: [<0000000000123790>] gmap_map_segment+0x9c/0x298
 #2:  (&(&mm->page_table_lock)->rlock){+.+.+.}, at: [<00000000001237a8>] gmap_map_segment+0xb4/0x298

Fix this by freeing the lock on the alloc path. This is ok, since the
gmap table is never freed until we call gmap_free, so the table we are
walking cannot go.
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The current code in setup_boot_command_line() uses a heuristic to
detect an EBCDIC command line. It checks if any of the bytes in
the command line has bit one (0x80) set. In that case it is assumed
that we have an EBCDIC string and the complete command line is
converted.

On s390 there are cases where the boot loader provides a kernel
command line that is NULL terminated, but has random data after
the NULL termination. In that case, setup_boot_command_line()
might misinterpret an ASCII string for an EBCDIC string. A
subsequent string conversion can then damage the ASCII string.

This patch solves the problem by checking for NULL termination.
If no EBCDIC character has been found until the the NULL
termination has been found, we now assume that we have an ASCII
string.
Signed-off-by: NMichael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Mask the extint_code parameter of the smp external interrupt handler
to get the interruption code. Otherwise emergency call interrupts
erroneously might be accounted as emergency signal interrupts.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

If oprofilefs_ulong_from_user() is called with count equals
zero, *val remains unchanged. Depending on the implementation it
might be uninitialized.

Change oprofilefs_ulong_from_user()'s interface to return count
on success. Thus, we are able to return early if count equals
zero which avoids using *val uninitialized. Fixing all users of
oprofilefs_ulong_ from_user().

This follows write syscall implementation when count is zero:
"If count is zero ... [and if] no errors are detected, 0 will be
returned without causing any other effect." (man 2 write)
Reported-By: NMike Waychison <mikew@google.com>
Signed-off-by: NRobert Richter <robert.richter@amd.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: <stable@vger.kernel.org>
Cc: oprofile-list <oprofile-list@lists.sourceforge.net>
Link: http://lkml.kernel.org/r/20111219153830.GH16765@erda.amd.comSigned-off-by: NIngo Molnar <mingo@elte.hu>

git commit 20b40a79 "signal race with restarting system calls"
added code to the poke_user/poke_user_compat to reset the system call
restart information in the thread-info if the PSW address is changed.
The purpose of that change has been to workaround old gdbs that do
not know about the REGSET_SYSTEM_CALL. It turned out that this is not
a good idea, it makes the behaviour of the debuggee dependent on the
order of specific ptrace call, e.g. the REGSET_SYSTEM_CALL register
set needs to be written last. And the workaround does not really fix
old gdbs, inferior calls on interrupted restarting system calls do not
work either way.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The last breaking event address is a read-only value, the regset misses the
.set function. If a PTRACE_SETREGSET is done for NT_S390_LAST_BREAK we
get an oops due to a branch to zero:

Kernel BUG at 0000000000000002 verbose debug info unavailable
illegal operation: 0001 #1 SMP
...
Call Trace:
(<0000000000158294> ptrace_regset+0x184/0x188)
 <00000000001595b6> ptrace_request+0x37a/0x4fc
 <0000000000109a78> arch_ptrace+0x108/0x1fc
 <00000000001590d6> SyS_ptrace+0xaa/0x12c
 <00000000005c7a42> sysc_noemu+0x16/0x1c
 <000003fffd5ec10c> 0x3fffd5ec10c
Last Breaking-Event-Address:
 <0000000000158242> ptrace_regset+0x132/0x188

Add a nop .set function to prevent the branch to zero.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Cc: stable@kernel.org

This patch makes sure we don't underindicate _PAGE_CHANGED in case
we have a race between an operation that changes the page and this
code path that hits us between page_get_storage_key and
page_set_storage_key. Note that we still have a potential
underindication on _PAGE_REFERENCED in the unlikely event that
the page was changed but not referenced _and_ someone references
the page in the race window. That's not considered to be a problem.
Signed-off-by: NCarsten Otte <cotte@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The TIF_SYSCALL bit needs to be cleared if the debugger changes the state
of the ptraced process in regard to the presence of a system call.
Otherwise the system call will be restarted although the debugger set up
an inferior call.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

In order to have the same behavior for kdump based stand-alone dump
as for the kexec method, the is_kdump_kernel() check (only true for
the kexec method) has to be replaced by the OLDMEM_BASE check (true
for both methods).
Signed-off-by: NMichael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

KVM on s390 always had a sync mmu. Any mapping change in userspace
mapping was always reflected immediately in the guest mapping.
- In older code the guest mapping was just an offset
- In newer code the last level page table is shared
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: NCarsten Otte <cotte@de.ibm.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

There is a potential host deadlock in the tprot intercept handling.
We must not hold the mmap semaphore while resolving the guest
address. If userspace is remapping, then the memory detection in
the guest is broken anyway so we can safely separate the
address translation from walking the vmas.
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: NCarsten Otte <cotte@de.ibm.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

SIGP sense running may cause an intercept on higher level
virtualization, so handle it by checking the CPUSTAT_RUNNING flag.
Signed-off-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NCarsten Otte <cotte@de.ibm.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

CPUSTAT_RUNNING was implemented signifying that a vcpu is not stopped.
This is not, however, what the architecture says: RUNNING should be
set when the host is acting on the behalf of the guest operating
system.

CPUSTAT_RUNNING has been changed to be set in kvm_arch_vcpu_load()
and to be unset in kvm_arch_vcpu_put().

For signifying stopped state of a vcpu, a host-controlled bit has
been used and is set/unset basically on the reverse as the old
CPUSTAT_RUNNING bit (including pushing it down into stop handling
proper in handle_stop()).

Cc: stable@kernel.org
Signed-off-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NCarsten Otte <cotte@de.ibm.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

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>