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>

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

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>

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>

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>

'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>

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

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>

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>

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>

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>

This patch implements the crash_map_pages() function for s390.
KEXEC_CRASH_MEM_ALIGN is set to HPAGE_SIZE, in order to support
kernel mappings that use large pages. We also use HPAGE_SIZE alignment
for CONFIG_HUGETLB_PAGE=n in order to have the same 1 MiB alignment on
all s390 systems.
Signed-off-by: NMichael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

This patch defines for s390 an ABI defined pointer to the vmcoreinfo note at
a well known address. With this patch tools are able to find this information
in dumps created by stand-alone or hypervisor dump tools.
Signed-off-by: NMichael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

This patch provides the architecture specific part of the s390 kdump
support.
Signed-off-by: NMichael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

PSW restart can be triggered on offline CPUs. If this happens, currently
the PSW restart code fails, because functions like smp_processor_id()
do not work on offline CPUs. This patch fixes this as follows:

If PSW restart is triggered on an offline CPU, the PSW restart (sigp restart)
is done a second time on another CPU that is online and the old CPU is
stopped afterwards.
Signed-off-by: NMichael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Use the ENTRY macro for the system call wrapper sys_setns_wrapper
similarly to the other wrappers.
Signed-off-by: NJan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

git commit 5e9a2692 "[S390] ptrace cleanup" introduced a regression
for the case when both a user PER set (e.g. a storage alteration trace) and
PTRACE_SINGLESTEP are active. The new code will overrule the user PER set
with a instruction-fetch PER set over the whole address space for ptrace
single stepping. The inferior process will be stopped after each instruction
with an instruction fetch event. Any other events that may have occurred
concurrently are not reported (e.g. storage alteration event) because the
control bits for them are not set. The solution is to merge the PER control
bits of the user PER set with the PER_EVENT_IFETCH control bit for
PTRACE_SINGLESTEP.

Cc: stable@kernel.org
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Fix this warning:
WARNING: vmlinux.o(.text+0x199b6): Section mismatch in reference from
the function alloc_masks() to the function .init.text:__alloc_bootmem()
Signed-off-by: NSebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The .start function and indirectly the .next function of the show_cpuinfo
sequential operation uses NR_CPUS as limit instead of nr_cpu_ids.
This can cause warnings like this:

WARNING: at /usr/src/linux/include/linux/cpumask.h:107
Process lscpu (pid: 575, task: 000000007deb4338, ksp: 000000007794f588)
Krnl PSW : 0704000180000000 0000000000106db4 (show_cpuinfo+0x108/0x234)
           R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:0 CC:0 PM:0 EA:3
Krnl GPRS: 0000000000000003 0000000000791988 000000000071b478 0000000000000004
           0000000000000001 0000000000000000 000000007d139500 0000000000000400
           0000000000000000 000000000070e24c 000000007d48d600 0000000000000005
           000000007d48d600 00000000004dfa10 0000000000106cf8 000000007794fcc0
Krnl Code: 0000000000106da8: 95001000           cli     0(%r1),0
           0000000000106dac: a774ffac           brc     7,106d04
           0000000000106db0: a7f40001           brc     15,106db2
          >0000000000106db4: 92011000           mvi     0(%r1),1
           0000000000106db8: a7f4ffa6           brc     15,106d04
           0000000000106dbc: c0e5000065b4       brasl   %r14,113924
           0000000000106dc2: c09000303a45       larl    %r9,70e24c
           0000000000106dc8: c020001eefd4       larl    %r2,4e4d70

Replacing NR_CPUS with nr_cpu_ids fixes it.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Current IRQ statistics support does not show detail counts for I/O
interrupts which are processed internally only. The result is a
summation count which is way off such as this one:

           CPU0       CPU1       CPU2
I/O:       1331        710        442
[...]
QAI:         15         16         16   [I/O] QDIO Adapter Interrupt
QDI:          1          0          0   [I/O] QDIO Interrupt
DAS:        706        645        381   [I/O] DASD
C15:         26         10          0   [I/O] 3215
C70:          0          0          0   [I/O] 3270
TAP:          0          0          0   [I/O] Tape
VMR:          0          0          0   [I/O] Unit Record Devices
LCS:          0          0          0   [I/O] LCS
CLW:          0          0          0   [I/O] CLAW
CTC:          0          0          0   [I/O] CTC
APB:          0          0          0   [I/O] AP Bus

Fix this by moving I/O interrupt accounting into the common I/O layer.
Signed-off-by: NPeter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

This allows jump-label entries to be cheaply updated on code which is
not yet live.
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Acked-by: NJason Baron <jbaron@redhat.com>
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Jan Glauber <jang@linux.vnet.ibm.com>

For s390 there is one additional byte associated with each page,
the storage key. This byte contains the referenced and changed
bits and needs to be included into the hibernation image.
If the storage keys are not restored to their previous state all
original pages would appear to be dirty. This can cause
inconsistencies e.g. with read-only filesystems.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

"s390: Use direct ktime path for s390 clockevent device" in linux-next
introduces this compile warning:

arch/s390/kernel/time.c: In function 's390_next_ktime':
arch/s390/kernel/time.c:118:2: warning:
  comparison of distinct pointer types lacks a cast [enabled by default]

Just use a u64 instead of an s64 variable. This is not a problem since it
will always contain a positive value.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Link: http://lkml.kernel.org/r/1316675957-5538-1-git-send-email-heiko.carstens@de.ibm.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

598841ca ([S390] use gmap address
spaces for kvm guest images) changed kvm to use a separate address
space for kvm guests. This address space was switched in __vcpu_run
In some cases (preemption, page fault) there is the possibility that
this address space switch is lost.
The typical symptom was a huge amount of validity intercepts or
random guest addressing exceptions.
Fix this by doing the switch in sie_loop and sie_exit and saving the
address space in the gmap structure itself. Also use the preempt
notifier.
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Acked-by: NAvi Kivity <avi@redhat.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>

The clock comparator on s390 uses the same format as the TOD clock.
If the value in the clock comparator is smaller than the current TOD
value an interrupt is pending. Use the CLOCK_EVT_FEAT_KTIME feature
to get the unmodified ktime of the next clockevent expiration and
use it to program the clock comparator without querying the TOD clock.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Cc: john stultz <johnstul@us.ibm.com>
Link: http://lkml.kernel.org/r/20110823133143.153017933@de.ibm.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>