s390/signal: always restore saved runtime instrumentation psw bit

Commit "s390: fix handling of runtime instrumentation psw bit" (5ebf250dab)
changed the behavior of setting the runtime instrumentation psw bit.  This
commit restores the original logic:

1. When returning from the signal handler, the runtime instrumentation psw bit
   is restored to its saved state.
2. If the runtime instrumentation psw bit is enabled during the signal handler,
   it is always turned off when leaving the signal handler.  The saved state
   is restored as described in 1.  That also implies that turning on runtime
   instrumentation in the signal handler is only effective while running in the
   signal context.

Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
s390/dasd: validate request size before building CCW/TCW request

An I/O request that does not read or write full blocks cannot be
translated into a correct CCW or TCW program and should be rejected
right away. In particular the code that creates TCW requests will not
notice this problem and create broken TCWs that will be rejected by
the hardware.

Signed-off-by: Stefan Weinhuber <wein@de.ibm.com>
Reference-ID: RQM1956
s390/mm: optimize copy_page

Always use the mvcl instruction to copy a page instead of mvpg or a
couple of mvc instructions.
Copying a huge page is 25% faster this way. Also bypass caches when
copying pages since only parts of a page will be used afterwards.
Especially when copying a huge page this would kick everything out
of the L1 and L2 data caches on a zEC12 machine.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
ALSA: firewire-lib: fix wrong value for FDF field as an empty packet

This commit fix out of specification about the value of FDF field in out packet
with 'no data'. This affects blocking mode.

According to IEC 61883-6, there is two way to generate AMDTP packets include no
data in blocking mode.

Way 1. an empty packet defined in IEC 61883-1
 - Size of packet is 2 quadlets.
 - The value of FDF is sfc.
 - The packet includes only CIP headers

Way 2. a special non-empty packet defined in IEC 61883-6
 - Size of packet is following to blocking mode
 - The value of FDF is 0xff. This value is 'NO-DATA'. This means 'The receiver'
   must ignore all the data in a CIP with this FDF code'.
 - The packet includes dummy data.

But current implementation is a combination of them.
 - Size of packet is 2 (way 1)
 - FDF = 0xff (way 2)
This causes BeBoB chipset cannot sound.

This patch applies Way 1.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Cc: Acked-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
cgroup: use a dedicated workqueue for cgroup destruction

Since be44562613851 ("cgroup: remove synchronize_rcu() from
cgroup_diput()"), cgroup destruction path makes use of workqueue.  css
freeing is performed from a work item from that point on and a later
commit, ea15f8ccdb430 ("cgroup: split cgroup destruction into two
steps"), moves css offlining to workqueue too.

As cgroup destruction isn't depended upon for memory reclaim, the
destruction work items were put on the system_wq; unfortunately, some
controller may block in the destruction path for considerable duration
while holding cgroup_mutex.  As large part of destruction path is
synchronized through cgroup_mutex, when combined with high rate of
cgroup removals, this has potential to fill up system_wq's max_active
of 256.

Also, it turns out that memcg's css destruction path ends up queueing
and waiting for work items on system_wq through work_on_cpu().  If
such operation happens while system_wq is fully occupied by cgroup
destruction work items, work_on_cpu() can't make forward progress
because system_wq is full and other destruction work items on
system_wq can't make forward progress because the work item waiting
for work_on_cpu() is holding cgroup_mutex, leading to deadlock.

This can be fixed by queueing destruction work items on a separate
workqueue.  This patch creates a dedicated workqueue -
cgroup_destroy_wq - for this purpose.  As these work items shouldn't
have inter-dependencies and mostly serialized by cgroup_mutex anyway,
giving high concurrency level doesn't buy anything and the workqueue's
@max_active is set to 1 so that destruction work items are executed
one by one on each CPU.

Hugh Dickins: Because cgroup_init() is run before init_workqueues(),
cgroup_destroy_wq can't be allocated from cgroup_init().  Do it from a
separate core_initcall().  In the future, we probably want to reorder
so that workqueue init happens before cgroup_init().

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Hugh Dickins <hughd@google.com>
Reported-by: Shawn Bohrer <shawn.bohrer@gmail.com>
Link: http://lkml.kernel.org/r/20131111220626.GA7509@sbohrermbp13-local.rgmadvisors.com
Link: http://lkml.kernel.org/g/alpine.LNX.2.00.1310301606080.2333@eggly.anvils
Cc: stable@vger.kernel.org # v3.9+
ahci: add support for IBM Akebono platform device

The new IBM Akebono board has a PPC476GTR SoC with an AHCI compliant
SATA controller. This patch adds a compatible property for the new SoC
to the AHCI platform driver.

Signed-off-by: Alistair Popple <alistair@popple.id.au>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: stable@vger.kernel.org
pata_arasan_cf: add missing clk_disable_unprepare() on error path

Add the missing clk_disable_unprepare() before return from cf_init()
in the error handling case.

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
workqueue: swap set_cpus_allowed_ptr() and PF_NO_SETAFFINITY

Move the setting of PF_NO_SETAFFINITY up before set_cpus_allowed()
in create_worker(). Otherwise userland can change ->cpus_allowed
in between.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
workqueue: fix ordered workqueues in NUMA setups

An ordered workqueue implements execution ordering by using single
pool_workqueue with max_active == 1.  On a given pool_workqueue, work
items are processed in FIFO order and limiting max_active to 1
enforces the queued work items to be processed one by one.

Unfortunately, 4c16bd327c ("workqueue: implement NUMA affinity for
unbound workqueues") accidentally broke this guarantee by applying
NUMA affinity to ordered workqueues too.  On NUMA setups, an ordered
workqueue would end up with separate pool_workqueues for different
nodes.  Each pool_workqueue still limits max_active to 1 but multiple
work items may be executed concurrently and out of order depending on
which node they are queued to.

Fix it by using dedicated ordered_wq_attrs[] when creating ordered
workqueues.  The new attrs match the unbound ones except that no_numa
is always set thus forcing all NUMA nodes to share the default
pool_workqueue.

While at it, add sanity check in workqueue creation path which
verifies that an ordered workqueues has only the default
pool_workqueue.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Libin <huawei.libin@huawei.com>
Cc: stable@vger.kernel.org
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
workqueue: fix comment typo for __queue_work()

It seems the "dying" should be "draining" here.

Signed-off-by: Li Bin <huawei.libin@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
workqueue: fix pool ID allocation leakage and remove BUILD_BUG_ON() in init_workqueues

When one work starts execution, the high bits of work's data contain
pool ID. It can represent a maximum of WORK_OFFQ_POOL_NONE. Pool ID
is assigned WORK_OFFQ_POOL_NONE when the work being initialized
indicating that no pool is associated and get_work_pool() uses it to
check the associated pool. So if worker_pool_assign_id() assigns a
ID greater than or equal WORK_OFFQ_POOL_NONE to a pool, it triggers
leakage, and it may break the non-reentrance guarantee.

This patch fix this issue by modifying the worker_pool_assign_id()
function calling idr_alloc() by setting @end param WORK_OFFQ_POOL_NONE.

Furthermore, in the current implementation, the BUILD_BUG_ON() in
init_workqueues makes no sense. The number of worker pools needed
cannot be determined at compile time, because the number of backing
pools for UNBOUND workqueues is dynamic based on the assigned custom
attributes. So remove it.

tj: Minor comment and indentation updates.

Signed-off-by: Li Bin <huawei.libin@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
ata: fix acpi_bus_get_device() return value check

Since acpi_bus_get_device() returns plain int and not acpi_status,
ACPI_FAILURE() should not be used for checking its return value.  Fix
that.

tj: Dropped unused local variable @status from odd_can_poweroff().
    Reported by kbuild test bot.

Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Aaron Lu <aaron.lu@intel.com>
Cc: linux-ide@vger.kernel.org
Cc: kbuild test robot <fengguang.wu@intel.com>
ahci: add Marvell 9230 to the AHCI PCI device list

Tested with a DAWICONTROL DC-624e on 3.10.10

Signed-off-by: Samir Benmendil <samir.benmendil@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Levente Kurusa <levex@linux.com>
Cc: stable@vger.kernel.org
s390/uaccess: add missing page table walk range check

When translating a user space address, the address must be checked against
the ASCE limit of the process. If the address is larger than the maximum
address that is reachable with the ASCE, an ASCE type exception must be
generated.

The current code simply ignored the higher order bits. This resulted in an
address wrap around in user space instead of an exception in user space.

Cc: stable@vger.kernel.org # v3.9+
Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
s390/time,vdso: convert to the new update_vsyscall interface

Switch to the improved update_vsyscall interface that provides
sub-nanosecond precision for gettimeofday and clock_gettime.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
s390,time: revert direct ktime path for s390 clockevent device

Git commit 4f37a68cdaf6dea833cfdded2a3e0c47c0f006da
"s390: Use direct ktime path for s390 clockevent device" makes use
of the CLOCK_EVT_FEAT_KTIME clockevent option to avoid the delta
calculation with ktime_get() in clockevents_program_event and the
get_tod_clock() in s390_next_event. This is based on the assumption
that the difference between the internal ktime and the hardware
clock is reflected in the wall_to_monotonic delta. But this is not
true, the ntp corrections are applied via changes to the tk->mult
multiplier and this is not reflected in wall_to_monotonic.

In theory this could be solved by using the raw monotonic clock
but it is simpler to switch back to the standard clock delta
calculation.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
s390/mm: handle asce-type exceptions as normal page fault

Git commit 9e34f2686bb088b211b6cac8772e1f644c6180f8
"s390/mm,tlb: tlb flush on page table upgrade fixup" removed the
exception handler for the asce-type exception. This is incorrect
as the user-copy with MVCOS can cause asce-type exceptions in
the kernel if a user pointer is too large. Those need to be
handled with do_no_context to branch to the fixup in the
user-copy code.

The simplest fix for this problem is to call do_dat_exception for
asce-type excpetions, as there is no vma for the address the code
will handle the exception correctly.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
arm64: let the core code deal with preempt_count

Commit f27dde8deef3 (sched: Add NEED_RESCHED to the preempt_count)
introduced the use of bit 31 in preempt_count for obscure scheduling
purposes.

This causes interrupts taken from EL0 to hit the (open coded) BUG when
this flag is flipped while handling the interrupt (we compare the
values before and after, and kill the kernel if they are different).

The fix is to stop messing with the preempt count entirely, as this
is already being dealt with in the generic code (irq_enter/irq_exit).

Tested on a dual A53 FPGA running cyclictest.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
arm64: dts: Reserve the memory used for secondary CPU release address

With the spin-table SMP booting method, secondary CPUs poll a location
passed in the DT. The foundation-v8.dts file doesn't have this memory
reserved and there is a risk of Linux using it before secondary CPUs are
started.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
arm64: Unmask asynchronous aborts when in kernel mode

The asynchronous aborts are generally fatal for the kernel but they can
be masked via the pstate A bit. If a system error happens while in
kernel mode, it won't be visible until returning to user space. This
patch enables this kind of abort early to help identifying the cause.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>