Commit Graph

1767 Commits

Author SHA1 Message Date
Linus Torvalds e627078a0c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull s390 updates from Martin Schwidefsky:
 "There is only one new feature in this pull for the 4.4 merge window,
  most of it is small enhancements, cleanup and bug fixes:

   - Add the s390 backend for the software dirty bit tracking.  This
     adds two new pgtable functions pte_clear_soft_dirty and
     pmd_clear_soft_dirty which is why there is a hit to
     arch/x86/include/asm/pgtable.h in this pull request.

   - A series of cleanup patches for the AP bus, this includes the
     removal of the support for two outdated crypto cards (PCICC and
     PCICA).

   - The irq handling / signaling on buffer full in the runtime
     instrumentation code is dropped.

   - Some micro optimizations: remove unnecessary memory barriers for a
     couple of functions: [smb_]rmb, [smb_]wmb, atomics, bitops, and for
     spin_unlock.  Use the builtin bswap if available and make
     test_and_set_bit_lock more cache friendly.

   - Statistics and a tracepoint for the diagnose calls to the
     hypervisor.

   - The CPU measurement facility support to sample KVM guests is
     improved.

   - The vector instructions are now always enabled for user space
     processes if the hardware has the vector facility.  This simplifies
     the FPU handling code.  The fpu-internal.h header is split into fpu
     internals, api and types just like x86.

   - Cleanup and improvements for the common I/O layer.

   - Rework udelay to solve a problem with kprobe.  udelay has busy loop
     semantics but still uses an idle processor state for the wait"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (66 commits)
  s390: remove runtime instrumentation interrupts
  s390/cio: de-duplicate subchannel validation
  s390/css: unneeded initialization in for_each_subchannel
  s390/Kconfig: use builtin bswap
  s390/dasd: fix disconnected device with valid path mask
  s390/dasd: fix invalid PAV assignment after suspend/resume
  s390/dasd: fix double free in dasd_eckd_read_conf
  s390/kernel: fix ptrace peek/poke for floating point registers
  s390/cio: move ccw_device_stlck functions
  s390/cio: move ccw_device_call_handler
  s390/topology: reduce per_cpu() invocations
  s390/nmi: reduce size of percpu variable
  s390/nmi: fix terminology
  s390/nmi: remove casts
  s390/nmi: remove pointless error strings
  s390: don't store registers on disabled wait anymore
  s390: get rid of __set_psw_mask()
  s390/fpu: split fpu-internal.h into fpu internals, api, and type headers
  s390/dasd: fix list_del corruption after lcu changes
  s390/spinlock: remove unneeded serializations at unlock
  ...
2015-11-04 11:31:31 -08:00
Martin Schwidefsky b38feccd66 s390: remove runtime instrumentation interrupts
The external interrupts for runtime instrumentation buffer-full
and runtime instrumentation halted are unused and have no current
user. Remove the support and ignore the second parameter of the
s390_runtime_instr system call from now on.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-11-03 14:40:51 +01:00
Martin Schwidefsky 55a423b6f1 s390/kernel: fix ptrace peek/poke for floating point registers
git commit 155e839a81
"s390/kernel: dynamically allocate FP register save area"
introduced a regression in regard to ptrace.

If the vector register extension is not present or unused the
ptrace peek of a floating pointer register return incorrect data
and the ptrace poke to a floating pointer register overwrites the
task structure starting at task->thread.fpu.fprs.

Cc: stable@kernel.org # v4.3
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-11-03 14:40:42 +01:00
Heiko Carstens 439eb131f7 s390/topology: reduce per_cpu() invocations
Each per_cpu() invocation generates extra code. Since there are a lot
of similiar calls in the topology code we can avoid a lot of them.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-10-27 09:34:39 +01:00
Heiko Carstens 36324963a3 s390/nmi: reduce size of percpu variable
Change the flag fields within struct mcck_struct to simple bit fields
to reduce the size of the structure which is used as percpu variable.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-10-27 09:33:57 +01:00
Heiko Carstens 975be635d9 s390/nmi: fix terminology
According to the architecture registers are validated and not
revalidated. So change comments and functions names to match.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-10-27 09:33:56 +01:00
Heiko Carstens dc6e15556a s390/nmi: remove casts
Remove all the casts to and from the machine check interruption code.
This patch changes struct mci to a union, which contains an anonymous
structure with the already known bits and in addition an unsigned
long field, which contains the raw machine check interruption code.

This allows to simply assign and decoce the interruption code value
without the need for all those casts we had all the time.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-10-27 09:33:55 +01:00
Heiko Carstens 3d68286a43 s390/nmi: remove pointless error strings
s390_handle_damage() has character string parameter which was used as
a pointer to verbose error message. The hope was (a lot of years ago)
when analyzing dumps that register R2 would still contain the pointer
and therefore it would be rather easy to tell what went wrong.

However gcc optimizes the strings away since a long time. And even if
it wouldn't it is necessary to have a close look at the machine check
interruption code to tell what's wrong.

So remove the pointless error strings.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-10-27 09:33:54 +01:00
Hendrik Brueckner b0753902d4 s390/fpu: split fpu-internal.h into fpu internals, api, and type headers
Split the API and FPU type definitions into separate header files
similar to "x86/fpu: Rename fpu-internal.h to fpu/internal.h" (78f7f1e54b).

The new header files and their meaning are:

asm/fpu/types.h:
	FPU related data types, needed for 'struct thread_struct' and
	'struct task_struct'.

asm/fpu/api.h:
	FPU related 'public' functions for other subsystems and device
	drivers.

asm/fpu/internal.h:
	FPU internal functions mainly used to convert
	FPU register contents in signal handling.

Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-10-16 09:41:12 +02:00
Heiko Carstens 29b0a8250b s390/etr,stp: fix possible deadlock on machine check
The first level machine check handler for etr and stp machine checks may
call queue_work() while in nmi context. This may deadlock e.g. if the
machine check happened when the interrupted context did hold a lock, that
also will be acquired by queue_work().
Therefore split etr and stp machine check handling into first and second
level handling. The second level handling will then issue the queue_work()
call in process context which avoids the potential deadlock.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-10-14 14:32:18 +02:00
Heiko Carstens db7e007fd6 s390/udelay: make udelay have busy loop semantics
When using systemtap it was observed that our udelay implementation is
rather suboptimal if being called from a kprobe handler installed by
systemtap.

The problem observed when a kprobe was installed on lock_acquired().
When the probe was hit the kprobe handler did call udelay, which set
up an (internal) timer and reenabled interrupts (only the clock comparator
interrupt) and waited for the interrupt.
This is an optimization to avoid that the cpu is busy looping while waiting
that enough time passes. The problem is that the interrupt handler still
does call irq_enter()/irq_exit() which then again can lead to a deadlock,
since some accounting functions may take locks as well.

If one of these locks is the same, which caused lock_acquired() to be
called, we have a nice deadlock.

This patch reworks the udelay code for the interrupts disabled case to
immediately leave the low level interrupt handler when the clock
comparator interrupt happens. That way no C code is being called and the
deadlock cannot happen anymore.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-10-14 14:32:13 +02:00
Christian Borntraeger e22cf8ca6f s390/cpumf: rework program parameter setting to detect guest samples
The program parameter can be used to mark hardware samples with
some token.  Previously, it was used to mark guest samples only.

Improve the program parameter doubleword by combining two parts,
the leftmost LPP part and the rightmost PID part.  Set the PID
part for processes by using the task PID.
To distinguish host and guest samples for the kernel (PID part
is zero), the guest must always set the program paramater to a
non-zero value.  Use the leftmost bit in the LPP part of the
program parameter to be able to detect guest kernel samples.

[brueckner@linux.vnet.ibm.com]: Split __LC_CURRENT and introduced
__LC_LPP. Corrected __LC_CURRENT users and adjusted assembler parts.
And updated the commit message accordingly.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-10-14 14:32:12 +02:00
Martin Schwidefsky 6a62b485ea s390/asm: make use of the OFFSET macro to define assember constants
The use of OFFSET instead of DEFINE makes the definitions in asm-offsets.c
more readable. While we are at it sort the defines for struct _lowcore
according to the field order and remove some unneeded defines.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-10-14 14:32:10 +02:00
Hendrik Brueckner 83abeffbd5 s390/entry: add assembler macro to conveniently tests under mask
Various functions in entry.S perform test-under-mask instructions
to test for particular bits in memory.  Because test-under-mask uses
a mask value of one byte, the mask value and the offset into the
memory must be calculated manually.  This easily introduces errors
and is hard to review and read.

Introduce the TSTMSK assembler macro to specify a mask constant and
let the macro calculate the offset and the byte mask to generate a
test-under-mask instruction.  The benefit is that existing symbolic
constants can now be used for tests.  Also the macro checks for
zero mask values and mask values that consist of multiple bytes.

Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-10-14 14:32:09 +02:00
Hendrik Brueckner 0ac277790e s390/fpu: add static FPU save area for init_task
Previously, the init task did not have an allocated FPU save area and
saving an FPU state was not possible.  Now if the vector extension is
always enabled, provide a static FPU save area to save FPU states of
vector instructions that can be executed quite early.

Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-10-14 14:32:08 +02:00
Hendrik Brueckner b5510d9b68 s390/fpu: always enable the vector facility if it is available
If the kernel detects that the s390 hardware supports the vector
facility, it is enabled by default at an early stage.  To force
it off, use the novx kernel parameter.  Note that there is a small
time window, where the vector facility is enabled before it is
forced to be off.

With enabling the vector facility by default, the FPU save and
restore functions can be improved.  They do not longer require
to manage expensive control register updates to enable or disable
the vector enablement control for particular processes.

Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-10-14 14:32:08 +02:00
Martin Schwidefsky b5a6b71b19 s390/diag: add tracepoint for diagnose calls
To be able to analyse problems in regard to hypervisor overhead
add a tracepoing for diagnose calls. It reports the number of
the diagnose issued, e.g.

            sshd-1385  [002] ....    42.701431: diagnose: nr=0x9c
          <idle>-0     [001] ..s.    43.587528: diagnose: nr=0x9c

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-10-14 14:32:06 +02:00
Martin Schwidefsky 1ec2772e0c s390/diag: add a statistic for diagnose calls
Introduce /sys/debug/kernel/diag_stat with a statistic how many diagnose
calls have been done by each CPU in the system.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-10-14 14:32:06 +02:00
Alexander Kuleshov 3c4aac86cb s390/crash_dump: use for_each_mem_range
The <linux/memblock.h> already provides for_each_mem_range() macro that
iterates through memblock areas from type_a and not included in type_b.
We can remove custom for_each_dump_mem_range() macro and use the
for_each_mem_range() instead.

Signed-off-by: Alexander Kuleshov <kuleshovmail@gmail.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2015-10-14 14:32:01 +02:00
Christian Borntraeger 33b5881d11 s390/vdso: use correct memory barrier
By definition smp_wmb only orders writes against writes. (Finish all
previous writes, and do not start any future write). To protect the
vdso init code against early reads on other CPUs, let's use a full
smp_mb at the end of vdso init. As right now smp_wmb is implemented
as full serialization, this needs no stable backport, but this change
will be necessary if we reimplement smp_wmb.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-10-14 14:32:01 +02:00
Ingo Molnar d3df65c198 Merge branch 'perf/urgent' into perf/core, before pulling new changes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-10-08 10:52:18 +02:00
Martin Schwidefsky 72d38b1978 s390/vtime: correct scaled cputime of partially idle CPUs
The calculation for the SMT scaling factor for a hardware thread
which has been partially idle needs to disregard the cycles spent
by the other threads of the core while the thread is idle.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-09-30 16:22:38 +02:00
Ingo Molnar 6afc0c269c Merge branch 'linus' into perf/core, to pick up fixes before applying new changes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-09-28 08:06:57 +02:00
Heiko Carstens 977108f89c s390: wire up separate socketcalls system calls
As discussed on linux-arch all architectures should wire up the separate
system calls that are hidden behind the socketcall multiplexer system call.

It's just a couple more system calls and gives us a very small performance
improvement.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-09-18 11:16:53 +02:00
Heiko Carstens 7681df456f s390/compat: remove superfluous compat wrappers
A couple of compat wrapper functions are simply trampolines to the real
system call. This happened because the compat wrapper defines will only
sign and zero extend system call parameters which are of different size
on s390/s390x (longs and pointers).
All other parameters will be correctly sign and zero extended by the
normal system call wrappers.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-09-18 11:16:52 +02:00
Heiko Carstens a55b2ae78c s390/compat: do not trace compat wrapper functions
Add notrace to the compat wrapper define to disable tracing of compat
wrapper functions. These are supposed to be very small and more or less
just a trampoline to the real system call.

Also fix indentation.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-09-18 11:16:50 +02:00
Mathieu Desnoyers 96d4ee8aaa s390/s390x: allocate sys_membarrier system call number
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: linux-api@vger.kernel.org
CC: Heiko Carstens <heiko.carstens@de.ibm.com>
CC: linux-s390@vger.kernel.org
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-09-17 13:43:44 +02:00
Heiko Carstens 022435713c s390: wire up userfaultfd system call
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-09-17 13:43:43 +02:00
Martin Schwidefsky 61cc37906b s390/vtime: correct scaled cputime for SMT
The scaled cputime is supposed to be derived from the normal per-thread
cputime by dividing it with the average thread density in the last interval.

The calculation of the scaling values for the average thread density is
incorrect. The current, incorrect calculation:

    Ci = cycle count with i active threads
    T = unscaled cputime, sT = scaled cputime
    sT = T * (C1 + C2 + ... + Cn) / (1*C1 + 2*C2 + ... + n*Cn)

The calculation happens to yield the correct numbers for the simple cases
with only one Ci value not zero. But for cases with multiple Ci values not
zero it fails. E.g. on a SMT-2 system with one thread active half the time
and two threads active for the other half of the time it fails, the scaling
factor should be 3/4 but the formula gives 2/3.

The correct formula is

    sT = T * (C1/1 + C2/2 + ... + Cn/n) / (C1 + C2 + ... + Cn)

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-09-17 13:43:43 +02:00
Hendrik Brueckner 58f8e9da33 s390/cpum_cf: Corrected return code for unauthorized counter sets
Previously, the cpum_cf PMU returned -EPERM if a counter is requested and
the counter set to which the counter belongs is not authorized.  According
to the perf_event_open() system call manual, an error code of EPERM indicates
an unsupported exclude setting or CAP_SYS_ADMIN is missing.

Use ENOENT to indicate that particular counters are not available when the
counter set which contains the counter is not authorized.  For generic events,
this might trigger a fall back, for example, to a software event.

Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-09-17 13:43:42 +02:00
Martin Schwidefsky 8d4bd0ed04 s390/compat: correct uc_sigmask of the compat signal frame
The uc_sigmask in the ucontext structure is an array of words to keep
the 64 signal bits (or 1024 if you ask glibc but the kernel sigset_t
only has 64 bits).

For 64 bit the sigset_t contains a single 8 byte word, but for 31 bit
there are two 4 byte words. The compat signal handler code uses a
simple copy of the 64 bit sigset_t to the 31 bit compat_sigset_t.
As s390 is a big-endian architecture this is incorrect, the two words
in the 31 bit sigset_t array need to be swapped.

Cc: <stable@vger.kernel.org>
Reported-by: Stefan Liebler <stli@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-09-17 13:43:42 +02:00
Heiko Carstens 9380cf5a88 s390: fix floating point register corruption
The critical section cleanup code misses to add the offset of the
thread_struct to the task address.
Therefore, if the critical section code gets executed, it may corrupt
the task struct or restore the contents of the floating point registers
from the wrong memory location.
Fixes d0164ee20d "s390/kernel: remove save_fpu_regs() parameter and use
__LC_CURRENT instead".

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-09-17 13:43:41 +02:00
Martin Schwidefsky 88d6425378 s390/hibernate: fix save and restore of vector registers
The swsusp_arch_suspend()/swsusp_arch_resume() functions currently only
save and restore the floating point registers. If the task that started
the hibernation process is using vector registers they can get lost.
To fix this just call save_fpu_regs in swsusp_arch_suspend(), the restore
will happen automatically on return to user space.

Reported-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-09-17 13:43:41 +02:00
Sukadev Bhattiprolu 8f3e5684d3 perf/core: Drop PERF_EVENT_TXN
We currently use PERF_EVENT_TXN flag to determine if we are in the middle
of a transaction. If in a transaction, we defer the schedulability checks
from pmu->add() operation to the pmu->commit() operation.

Now that we have "transaction types" (PERF_PMU_TXN_ADD, PERF_PMU_TXN_READ)
we can use the type to determine if we are in a transaction and drop the
PERF_EVENT_TXN flag.

When PERF_EVENT_TXN is dropped, the cpuhw->group_flag on some architectures
becomes unused, so drop that field as well.

This is an extension of the Powerpc patch from Peter Zijlstra to s390,
Sparc and x86 architectures.

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Link: http://lkml.kernel.org/r/1441336073-22750-11-git-send-email-sukadev@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-09-13 11:27:30 +02:00
Sukadev Bhattiprolu fbbe070115 perf/core: Add a 'flags' parameter to the PMU transactional interfaces
Currently, the PMU interface allows reading only one counter at a time.
But some PMUs like the 24x7 counters in Power, support reading several
counters at once. To leveage this functionality, extend the transaction
interface to support a "transaction type".

The first type, PERF_PMU_TXN_ADD, refers to the existing transactions,
i.e. used to _schedule_ all the events on the PMU as a group. A second
transaction type, PERF_PMU_TXN_READ, will be used in a follow-on patch,
by the 24x7 counters to read several counters at once.

Extend the transaction interfaces to the PMU to accept a 'txn_flags'
parameter and use this parameter to ignore any transactions that are
not of type PERF_PMU_TXN_ADD.

Thanks to Peter Zijlstra for his input.

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
[peterz: s390 compile fix]
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Link: http://lkml.kernel.org/r/1441336073-22750-3-git-send-email-sukadev@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-09-13 11:27:25 +02:00
Linus Torvalds ca520cab25 Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking and atomic updates from Ingo Molnar:
 "Main changes in this cycle are:

   - Extend atomic primitives with coherent logic op primitives
     (atomic_{or,and,xor}()) and deprecate the old partial APIs
     (atomic_{set,clear}_mask())

     The old ops were incoherent with incompatible signatures across
     architectures and with incomplete support.  Now every architecture
     supports the primitives consistently (by Peter Zijlstra)

   - Generic support for 'relaxed atomics':

       - _acquire/release/relaxed() flavours of xchg(), cmpxchg() and {add,sub}_return()
       - atomic_read_acquire()
       - atomic_set_release()

     This came out of porting qwrlock code to arm64 (by Will Deacon)

   - Clean up the fragile static_key APIs that were causing repeat bugs,
     by introducing a new one:

       DEFINE_STATIC_KEY_TRUE(name);
       DEFINE_STATIC_KEY_FALSE(name);

     which define a key of different types with an initial true/false
     value.

     Then allow:

       static_branch_likely()
       static_branch_unlikely()

     to take a key of either type and emit the right instruction for the
     case.  To be able to know the 'type' of the static key we encode it
     in the jump entry (by Peter Zijlstra)

   - Static key self-tests (by Jason Baron)

   - qrwlock optimizations (by Waiman Long)

   - small futex enhancements (by Davidlohr Bueso)

   - ... and misc other changes"

* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (63 commits)
  jump_label/x86: Work around asm build bug on older/backported GCCs
  locking, ARM, atomics: Define our SMP atomics in terms of _relaxed() operations
  locking, include/llist: Use linux/atomic.h instead of asm/cmpxchg.h
  locking/qrwlock: Make use of _{acquire|release|relaxed}() atomics
  locking/qrwlock: Implement queue_write_unlock() using smp_store_release()
  locking/lockref: Remove homebrew cmpxchg64_relaxed() macro definition
  locking, asm-generic: Add _{relaxed|acquire|release}() variants for 'atomic_long_t'
  locking, asm-generic: Rework atomic-long.h to avoid bulk code duplication
  locking/atomics: Add _{acquire|release|relaxed}() variants of some atomic operations
  locking, compiler.h: Cast away attributes in the WRITE_ONCE() magic
  locking/static_keys: Make verify_keys() static
  jump label, locking/static_keys: Update docs
  locking/static_keys: Provide a selftest
  jump_label: Provide a self-test
  s390/uaccess, locking/static_keys: employ static_branch_likely()
  x86, tsc, locking/static_keys: Employ static_branch_likely()
  locking/static_keys: Add selftest
  locking/static_keys: Add a new static_key interface
  locking/static_keys: Rework update logic
  locking/static_keys: Add static_key_{en,dis}able() helpers
  ...
2015-09-03 15:46:07 -07:00
Linus Torvalds 5e359bf221 Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer updates from Thomas Gleixner:
 "Rather large, but nothing exiting:

   - new range check for settimeofday() to prevent that boot time
     becomes negative.
   - fix for file time rounding
   - a few simplifications of the hrtimer code
   - fix for the proc/timerlist code so the output of clock realtime
     timers is accurate
   - more y2038 work
   - tree wide conversion of clockevent drivers to the new callbacks"

* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (88 commits)
  hrtimer: Handle failure of tick_init_highres() gracefully
  hrtimer: Unconfuse switch_hrtimer_base() a bit
  hrtimer: Simplify get_target_base() by returning current base
  hrtimer: Drop return code of hrtimer_switch_to_hres()
  time: Introduce timespec64_to_jiffies()/jiffies_to_timespec64()
  time: Introduce current_kernel_time64()
  time: Introduce struct itimerspec64
  time: Add the common weak version of update_persistent_clock()
  time: Always make sure wall_to_monotonic isn't positive
  time: Fix nanosecond file time rounding in timespec_trunc()
  timer_list: Add the base offset so remaining nsecs are accurate for non monotonic timers
  cris/time: Migrate to new 'set-state' interface
  kernel: broadcast-hrtimer: Migrate to new 'set-state' interface
  xtensa/time: Migrate to new 'set-state' interface
  unicore/time: Migrate to new 'set-state' interface
  um/time: Migrate to new 'set-state' interface
  sparc/time: Migrate to new 'set-state' interface
  sh/localtimer: Migrate to new 'set-state' interface
  score/time: Migrate to new 'set-state' interface
  s390/time: Migrate to new 'set-state' interface
  ...
2015-09-01 14:04:50 -07:00
Linus Torvalds 9c6a019c6e Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull s390 updates from Martin Schwidefsky:
 "The big one is support for fake NUMA, splitting a really large machine
  in more manageable piece improves performance in some cases, e.g. for
  a KVM host.

  The FICON Link Incident handling has been improved, this helps the
  operator to identify degraded or non-operational FICON connections.

  The save and restore of floating point and vector registers has been
  overhauled to allow the future use of vector registers in the kernel.

  A few small enhancement, magic sys-requests for the vt220 console via
  SCLP, some more assembler code has been converted to C, the PCI error
  handling is improved.

  And the usual cleanup and bug fixing"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (59 commits)
  s390/jump_label: Use %*ph to print small buffers
  s390/sclp_vt220: support magic sysrequests
  s390/ctrlchar: improve handling of magic sysrequests
  s390/numa: remove superfluous ARCH_WANT defines
  s390/3270: redraw screen on unsolicited device end
  s390/dcssblk: correct out of bounds array indexes
  s390/mm: simplify page table alloc/free code
  s390/pci: move debug messages to debugfs
  s390/nmi: initialize control register 0 earlier
  s390/zcrypt: use msleep() instead of mdelay()
  s390/hmcdrv: fix interrupt registration
  s390/setup: fix novx parameter
  s390/uaccess: remove uaccess_primary kernel parameter
  s390: remove unneeded sizeof(void *) comparisons
  s390/facilities: remove transactional-execution bits
  s390/numa: re-add DIE sched_domain_topology_level
  s390/dasd: enhance CUIR scope detection
  s390/dasd: fix failing path verification
  s390/vdso: emit a GNU hash
  s390/numa: make core to node mapping data dynamic
  ...
2015-08-31 15:11:53 -07:00
Linus Torvalds 44e98edcd1 A very small release for x86 and s390 KVM.
s390: timekeeping changes, cleanups and fixes
 
 x86: support for Hyper-V MSRs to report crashes, and a bunch of cleanups.
 
 One interesting feature that was planned for 4.3 (emulating the local
 APIC in kernel while keeping the IOAPIC and 8254 in userspace) had to
 be delayed because Intel complained about my reading of the manual.
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Merge tag 'kvm-4.3-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull kvm updates from Paolo Bonzini:
 "A very small release for x86 and s390 KVM.

   - s390: timekeeping changes, cleanups and fixes

   - x86: support for Hyper-V MSRs to report crashes, and a bunch of
     cleanups.

  One interesting feature that was planned for 4.3 (emulating the local
  APIC in kernel while keeping the IOAPIC and 8254 in userspace) had to
  be delayed because Intel complained about my reading of the manual"

* tag 'kvm-4.3-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (42 commits)
  x86/kvm: Rename VMX's segment access rights defines
  KVM: x86/vPMU: Fix unnecessary signed extension for AMD PERFCTRn
  kvm: x86: Fix error handling in the function kvm_lapic_sync_from_vapic
  KVM: s390: Fix assumption that kvm_set_irq_routing is always run successfully
  KVM: VMX: drop ept misconfig check
  KVM: MMU: fully check zero bits for sptes
  KVM: MMU: introduce is_shadow_zero_bits_set()
  KVM: MMU: introduce the framework to check zero bits on sptes
  KVM: MMU: split reset_rsvds_bits_mask_ept
  KVM: MMU: split reset_rsvds_bits_mask
  KVM: MMU: introduce rsvd_bits_validate
  KVM: MMU: move FNAME(is_rsvd_bits_set) to mmu.c
  KVM: MMU: fix validation of mmio page fault
  KVM: MTRR: Use default type for non-MTRR-covered gfn before WARN_ON
  KVM: s390: host STP toleration for VMs
  KVM: x86: clean/fix memory barriers in irqchip_in_kernel
  KVM: document memory barriers for kvm->vcpus/kvm->online_vcpus
  KVM: x86: remove unnecessary memory barriers for shared MSRs
  KVM: move code related to KVM_SET_BOOT_CPU_ID to x86
  KVM: s390: log capability enablement and vm attribute changes
  ...
2015-08-31 08:27:44 -07:00
Alexander Kuleshov e4ec735108 s390/jump_label: Use %*ph to print small buffers
printk() supports %*ph format specifier for printing a small buffers,
let's use it intead of %02x %02x...

Signed-off-by: Alexander Kuleshov <kuleshovmail@gmail.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-08-27 09:39:04 +02:00
Heiko Carstens 24d05ff863 s390/nmi: initialize control register 0 earlier
Change machine_check_init() to an early_initcall(). This makes sure it will
be called before all other cpus are online and therfore saves us a lot of
pointless smp_call_function() calls.
The control register settings will be forwarded to the other cpus when they
will be brought online.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-08-19 10:40:38 +02:00
Martin Schwidefsky 89b1145e93 s390/setup: fix novx parameter
The novx parameter disables the vector facility but the HWCAP_S390_VXRS
bit in the ELf hardware capabilies is always set if the machine has
the vector facility. If the user space program uses the "vx" string
in the features field of /proc/cpuinfo to utilize vector instruction
it will crash if the novx kernel paramter is set.

Convert setup_hwcaps to an arch_initcall and use MACHINE_HAS_VX to
decide if the HWCAPS_S390_VXRS bit needs to be set.

Cc: stable@vger.kernel.org # 3.18+
Reported-by: Ulrich Weigand <uweigand@de.ibm.com>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-08-19 10:40:04 +02:00
Heiko Carstens a69db2f6ad s390/facilities: remove transactional-execution bits
Remove the two facility bits

50 - constrained transactional-execution facility
74 - transactional-execution facility

from the required facilities if the kernel is built with -march=zEC12.

E.g. z/VM 6.3 doesn't virtualize the TX facility yet. Therefore a kernel
built with -march=zEC12 and ipl'ed on a zEC12 machine as a z/VM 6.3 guest
will emit a message about the missing facilities and stop working.

The kernel however doesn't make use of the TX facility, therefore remove
the two TX related facility bits and fix this unpleasant behavior.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-08-19 10:03:34 +02:00
Michael Holzheu c0e5ddab6e s390/numa: re-add DIE sched_domain_topology_level
By accident this level has been removed by the NUMA infrastructure patch.
For non-NUMA systems with CPUs that span more than one book, this makes
the scheduler only use one of the books and the other books remain idle.

Fix this and re-add the missing level.

For NUMA and non-NUMA we have the following scheduling domains and groups:

 - SMT  (Groups: CPU threads)
 - MC   (Groups: Cores)
 - BOOK (Groups: Books)

For the non-NUMA case we have one last level scheduling domain:

 - DIE  (Groups: Whole system, has all CPUs -> cpu_cpu_mask)

For the NUMA case we have the following two last level scheduling domains:

 - DIE  (Groups: NUMA nodes -> cpu_cpu_mask -> returns node siblings)
 - NUMA (Groups: Whole system, has all CPUs -> created in sched_init_numa())

Fixes: e8054b654b ("s390/numa: add topology tree infrastructure")
Reported-and-tested-by: Evgeny Cherkashin <Eugene.Crosser@ru.ibm.com>
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-08-19 10:03:14 +02:00
Ingo Molnar f52609fdab Merge branch 'locking/arch-atomic' into locking/core, because it's ready for upstream
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-08-12 11:44:30 +02:00
Viresh Kumar 07aeed3f9b s390/time: Migrate to new 'set-state' interface
Migrate s390 driver to the new 'set-state' interface provided by
clockevents core, the earlier 'set-mode' interface is marked obsolete
now.

This also enables us to implement callbacks for new states of clockevent
devices, for example: ONESHOT_STOPPED.

We weren't doing anything in the ->set_mode() callback. So, this patch
doesn't provide any set-state callbacks.

Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: linux390@de.ibm.com
Cc: linux-s390@vger.kernel.org
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2015-08-10 11:41:03 +02:00
Martin Schwidefsky aad1b688c9 s390/vdso: emit a GNU hash
As proposed by Andy Lutomirski create the SysV and the GNU hash
for the vdso objects. This may make some dynamic loaders a bit
faster.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-08-07 09:57:39 +02:00
Michael Holzheu 3a3814c28b s390/topology: remove topology lock
Since we are already protected by the "sched_domains_mutex" lock, we can
safely remove the topology lock.

Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-08-07 09:56:58 +02:00
Fan Zhang fdf036507f KVM: s390: host STP toleration for VMs
If the host has STP enabled, the TOD of the host will be changed during
synchronization phases. These are performed during a stop_machine() call.

As the guest TOD is based on the host TOD, we have to make sure that:
- no VCPU is in the SIE (implicitly guaranteed via stop_machine())
- manual guest TOD calculations are not affected

"Epoch" is the guest TOD clock delta to the host TOD clock. We have to
adjust that value during the STP synchronization and make sure that code
that accesses the epoch won't get interrupted in between (via disabling
preemption).

Signed-off-by: Fan Zhang <zhangfan@linux.vnet.ibm.com>
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2015-08-04 14:38:37 +02:00
Martin Schwidefsky f341b8dff9 s390/vtime: limit MT scaling value updates
The MT scaling values are updated on each calll to do_account_vtime.
This function is called for each HZ interrupt and for each context
switch. Context switch can happen often, the STCCTM instruction
on this path is noticeable. Limit the updates to once per jiffy.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-08-04 14:26:17 +02:00