There's a preemption race in the set_task_cpu() debug check in
that when we get preempted after setting task->state we'd still
be on the rq proper, but fail the test.

Check for preempted tasks, since those are always on the RQ.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20091217121830.137155561@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Since everybody is lazy and prone to forgetting things, make the
compiler help us a bit.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20091217121830.060186433@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Neglected because its hidden... (who reads comments anyway)
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20091217121829.970166036@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

We grew 3 new task states since the last time someone touched
it.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20091217121829.892737686@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

So that we don't keep forgetting about it.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20091217121829.815779372@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

In practice, it is harmless to voluntarily sleep in a
rcu_read_lock() section if we are running under preempt rcu, but
it is illegal if we build a kernel running non-preemptable rcu.

Currently, might_sleep() doesn't notice sleepable operations
under rcu_read_lock() sections if we are running under
preemptable rcu because preempt_count() is left untouched after
rcu_read_lock() in this case. But we want developers who test
their changes under such config to notice the "sleeping while
atomic" issues.

So we add rcu_read_lock_nesting to prempt_count() in
might_sleep() checks.

[ v2: Handle rcu-tiny ]
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <1260991265-8451-1-git-send-regression-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
LKML-Reference: <20091216170517.807938893@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Rearrange code a bit now that its a simpler function.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
LKML-Reference: <20091216170518.269101883@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

In order to remove the cfs_rq dependency from set_task_cpu() we
need to ensure the task is cfs_rq invariant for all callsites.

The simple approach is to substract cfs_rq->min_vruntime from
se->vruntime on dequeue, and add cfs_rq->min_vruntime on
enqueue.

However, this has the downside of breaking FAIR_SLEEPERS since
we loose the old vruntime as we only maintain the relative
position.

To solve this, we observe that we only migrate runnable tasks,
we do this using deactivate_task(.sleep=0) and
activate_task(.wakeup=0), therefore we can restrain the
min_vruntime invariance to that state.

The only other case is wakeup balancing, since we want to
maintain the old vruntime we cannot make it relative on dequeue,
but since we don't migrate inactive tasks, we can do so right
before we activate it again.

This is where we need the new pre-wakeup hook, we need to call
this while still holding the old rq->lock. We could fold it into
->select_task_rq(), but since that has multiple callsites and
would obfuscate the locking requirements, that seems like a
fudge.

This leaves the fork() case, simply make sure that ->task_fork()
leaves the ->vruntime in a relative state.

This covers all cases where set_task_cpu() gets called, and
ensures it sees a relative vruntime.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
LKML-Reference: <20091216170518.191697025@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

As will be apparent in the next patch, we need a pre wakeup hook
for sched_fair task migration, hence rename the post wakeup hook
and one pre wakeup.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
LKML-Reference: <20091216170518.114746117@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Since kthread_bind() lost its dependencies on sched.c, move it
back where it came from.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
LKML-Reference: <20091216170518.039524041@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Since select_task_rq() is now responsible for guaranteeing
->cpus_allowed and cpu_active_mask, we need to verify this.

select_task_rq_rt() can blindly return
smp_processor_id()/task_cpu() without checking the valid masks,
select_task_rq_fair() can do the same in the rare case that all
SD_flags are disabled.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
LKML-Reference: <20091216170517.961475466@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Since we access ->cpus_allowed without holding rq->lock we need
a retry loop to validate the result, this comes for near free
when we merge sched_migrate_task() into sched_exec() since that
already does the needed check.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
LKML-Reference: <20091216170517.884743662@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

In order to clean up the set_task_cpu() rq dependencies we need
to ensure it is never called on blocked tasks because such usage
does not pair with consistent rq->lock usage.

This puts the migration burden on ttwu().

Furthermore we need to close a race against changing
->cpus_allowed, since select_task_rq() runs with only preemption
disabled.

For sched_fork() this is safe because the child isn't in the
tasklist yet, for wakeup we fix this by synchronizing
set_cpus_allowed_ptr() against TASK_WAKING, which leaves
sched_exec to be a problem

This also closes a hole in (6ad4c188 sched: Fix balance vs
hotplug race) where ->select_task_rq() doesn't validate the
result against the sched_domain/root_domain.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
LKML-Reference: <20091216170517.807938893@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

For later convenience use TASK_WAKING for fresh tasks.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
LKML-Reference: <20091216170517.732561278@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

We should skip !SD_LOAD_BALANCE domains.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
LKML-Reference: <20091216170517.653578430@chello.nl>
CC: stable@kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Make sure not to access sched_fair fields before verifying it is
indeed a sched_fair task.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
CC: stable@kernel.org
LKML-Reference: <20091216170517.577998058@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Sachin found cpu hotplug test failures on powerpc, which made
the kernel hang on his POWER box.

The problem is that we fail to re-activate a cpu when a
hot-unplug fails. Fix this by moving the de-activation into
_cpu_down after doing the initial checks.

Remove the synchronize_sched() calls and rely on those implied
by rebuilding the sched domains using the new mask.
Reported-by: Sachin Sant <sachinp@in.ibm.com>
Signed-off-by: Xiaotian Feng <dfeng@redhat.com>
Tested-by: Sachin Sant <sachinp@in.ibm.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
LKML-Reference: <20091216170517.500272612@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

A UP machine has 1 active cpu, not having the boot-cpu in the
active map when starting the scheduler confuses things.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
LKML-Reference: <20091216170517.423469527@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Conflicts:
	kernel/sched_idletask.c

Merge reason: resolve the conflicts, pick up latest changes.
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Caused by commit 0b83ddeb ("MFD:
twl4030: add twl4030_codec MFD as a new child to the core") interacting
with commit b07682b6 ("mfd: Rename
twl4030* driver files to enable re-use").

This file seems to have been missed in the renaming.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: Peter Ujfalusi <peter.ujfalusi@nokia.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

* 'for-linus' of git://oss.sgi.com/xfs/xfs:
  xfs: event tracing support
  xfs: change the xfs_iext_insert / xfs_iext_remove
  xfs: cleanup bmap extent state macros

* git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-2.6-dm: (80 commits)
  dm snapshot: use merge origin if snapshot invalid
  dm snapshot: report merge failure in status
  dm snapshot: merge consecutive chunks together
  dm snapshot: trigger exceptions in remaining snapshots during merge
  dm snapshot: delay merging a chunk until writes to it complete
  dm snapshot: queue writes to chunks being merged
  dm snapshot: add merging
  dm snapshot: permit only one merge at once
  dm snapshot: support barriers in snapshot merge target
  dm snapshot: avoid allocating exceptions in merge
  dm snapshot: rework writing to origin
  dm snapshot: add merge target
  dm exception store: add merge specific methods
  dm snapshot: create function for chunk_is_tracked wait
  dm snapshot: make bio optional in __origin_write
  dm mpath: reject messages when device is suspended
  dm: export suspended state to targets
  dm: rename dm_suspended to dm_suspended_md
  dm: swap target postsuspend call and setting suspended flag
  dm crypt: add plain64 iv
  ...

* 'for-2.6.33' of git://git.kernel.dk/linux-2.6-block:
  cfq: set workload as expired if it doesn't have any slice left
  Fix a CFQ crash in "for-2.6.33" branch of block tree
  cfq: Remove wait_request flag when idle time is being deleted
  cfq-iosched: commenting non-obvious initialization
  cfq-iosched: Take care of corner cases of group losing share due to deletion
  cfq-iosched: Get rid of cfqq wait_busy_done flag
  cfq: Optimization for close cooperating queue searching
  block,xd: Delay allocation of DMA buffers until device is known
  drbd: Following the hmac change to SHASH (see linux commit 8bd1209c)
  cfq-iosched: reduce write depth only if sync was delayed

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6:
  ALSA: ac97_codec - increase timeout for analog sections to 5 second
  ASoC: Correct code taking the size of a pointer
  ALSA: hda - Add PCI IDs for Nvidia G2xx-series
  ALSA: sound/isa/gus: Correct code taking the size of a pointer
  ALSA: hda: Fix max PCM level to 0 dB for AD1981_HP
  ALSA: hda: Use ALC260_WILL quirk for another Acer model (0x1025007f)

Merge branch 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (26 commits)
  clockevents: Convert to raw_spinlock
  clockevents: Make tick_device_lock static
  debugobjects: Convert to raw_spinlocks
  perf_event: Convert to raw_spinlock
  hrtimers: Convert to raw_spinlocks
  genirq: Convert irq_desc.lock to raw_spinlock
  smp: Convert smplocks to raw_spinlocks
  rtmutes: Convert rtmutex.lock to raw_spinlock
  sched: Convert pi_lock to raw_spinlock
  sched: Convert cpupri lock to raw_spinlock
  sched: Convert rt_runtime_lock to raw_spinlock
  sched: Convert rq->lock to raw_spinlock
  plist: Make plist debugging raw_spinlock aware
  bkl: Fixup core_lock fallout
  locking: Cleanup the name space completely
  locking: Further name space cleanups
  alpha: Fix fallout from locking changes
  locking: Implement new raw_spinlock
  locking: Convert raw_rwlock functions to arch_rwlock
  locking: Convert raw_rwlock to arch_rwlock
  ...

* git://git.kernel.org/pub/scm/linux/kernel/git/hskinnemoen/avr32-2.6:
  avr32: update default configurations for ATNGW100, ATSTK1002 and ATSTK1006
  avr32: add default configurations for ATNGW100 mkII and EVKLCD10X
  avr32: add support for ATNGW100 mkII board
  avr32: convert to asm-generic/hardirq.h
  avr32: add two new at91 to cpu.h definition
  avr32: clean up linker script using standard macros.
  avr32: MRMT: correct setup of SPI slaves
  avr32: function for independently setting up SPI slaves
  avr32: re-instate MCI WP/CD pin assignments for ATNGW100

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6:
  sparc64: Fix clock event multiplier printf format.
  sparc64: Use clock{source,events}_calc_mult_shift().
  sparc64: Use free_bootmem_late() in mdesc_lmb_free().
  sparc: Add alignment and emulation fault perf events.
  sparc64: Add syscall tracepoint support.
  sparc: Stop trying to be so fancy and use __builtin_{memcpy,memset}()
  sparc: Use __builtin_object_size() to validate the buffer size for copy_from_user()
  sparc64: Add some missing __kprobes annotations to kernel fault paths.
  sparc64: Use kprobes_built_in() to avoid ifdefs in fault_64.c
  sparc: Validate that kprobe address is 4-byte aligned.
  sparc64: Don't specify IRQF_SHARED for LDC interrupts.
  sparc64: Fix stack debugging IRQ stack regression.
  sparc64: Fix overly strict range type matching for PCI devices.

* git://git.infradead.org/battery-2.6:
  power_supply_sysfs: Handle -ENODATA in a special way
  wm831x_backup: Remove unused variables
  gta02: Set pcf50633 charger_reference_current_ma
  pcf50633: Query charger status directly
  pcf50633: Properly reenable charging when the supply conditions change
  pcf50633: Get rid of charging restart software auto-triggering
  pcf50633: introduces battery charging current control
  pcf50633: Add ac power supply class to the charger
  wm831x: Factor out WM831x backup battery charger

* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb-2.6:
  USB: Close usb_find_interface race v3
  Revert "USB: Close usb_find_interface race"

[akpm@linux-foundation.org: s/q/g/ (Randy)]
Signed-off-by: Samu Onkalo <samu.p.onkalo@nokia.com>
Acked-by: Éric Piel <Eric.Piel@tremplin-utc.net>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Report output values as 1/1000 of earth gravity.

Output values from lis3 can be read from sysfs position entry and from
input device.  Input device can be accessed as event device and as
joystick device.  Joystick device can be in two modes.  Meaning of the
output values varies from case to case depending on the chip type and
configuration (scale).  Only joystick interface in JS_CORR_BROKEN mode
returned somehow similar output values in different configurations.
Joystick device is in that state by default in case of lis3.

Position sysfs entry, input event device and raw joystick device have been
little bit broken since meaning of the output values has been varied
between 12 and 8 bit devices.  Applications which relayed on those methods
failed if the chip is different than the expected one.

This patch converts output values to mean similar thing in different
configurations.  Both 8 and 12 bit devices reports now same acceleration
values.  If somebody implements full scale support to the driver, output
values will still mean the same.  Scaling factor and input device range
must be updated in that case.

Joystick interface in JS_CORR_BROKEN mode is not touched by this patch.
All other interfaces have different scale after this change.  For 12 bit
device scaling factor is 0.977 which keeps scaled and unscaled values are
quite close to each others.  For 8 bit device, scaled values are 18 times
bigger than unscaled values.
Signed-off-by: Samu Onkalo <samu.p.onkalo@nokia.com>
Acked-by: Éric Piel <Eric.Piel@tremplin-utc.net>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

It is possible to read position information at the chip measurement rate
via sysfs.  This patch adds possibility to configure chip measurement
rate.
Signed-off-by: Samu Onkalo <samu.p.onkalo@nokia.com>
Signed-off-by: Éric Piel <Eric.Piel@tremplin-utc.net>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Chip is calibrated by the manufacturer.  There is no need to calibarate it
at driver level.  If the chip is used as a joystick, calibaration can be
done using joystick device calibration mechanism.
Signed-off-by: Samu Onkalo <samu.p.onkalo@nokia.com>
Acked-by: Éric Piel <Eric.Piel@tremplin-utc.net>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Implement selftest feature as specified by chip manufacturer.  Control:
read selftest sysfs entry

Response: "OK x y z" or "FAIL x y z"

where x, y, and z are difference between selftest mode and normal mode.
Test is passed when values are within acceptance limit values.

Acceptance limits are provided via platform data.  See chip spesifications
for acceptance limits.  If limits are not properly set, OK / FAIL decision
is meaningless.  However, userspace application can still make decision
based on the numeric x, y, z values.

Selftest is meant for HW diagnostic purposes.  It is not meant to be
called during normal use of the chip.  It may cause false interrupt
events.  Selftest mode delays polling of the normal results but it doesn't
cause wrong values.  Chip must be in static state during selftest.  Any
acceration during the test causes most probably failure.
Signed-off-by: Samu Onkalo <samu.p.onkalo@nokia.com>
Acked-by: Éric Piel <Eric.Piel@tremplin-utc.net>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Lis3 accelerometer sensors have quite long power on delay (up to 125
ms). This patch adds necessary delay to power on sequence for currently
supported lis3 chips.
Signed-off-by: Samu Onkalo <samu.p.onkalo@nokia.com>
Tested-by: Éric Piel <eric.piel@tremplin-utc.net>
Acked-by: Éric Piel <eric.piel@tremplin-utc.net>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Originally the driver was only targeted to 12bits sensors.  When support
for 8bits sensors was added, some slight difference in the registers were
overlooked.  This should fix it, both for initialization, and for
displaying the rate.
Reported-by: Kalhan Trisal <kalhan.trisal@intel.com>
Reported-by: Christoph Plattner <christoph.plattner@gmx.at>
Tested-by: Christoph Plattner <christoph.plattner@gmx.at>
Tested-by: Samu Onkalo <samu.p.onkalo@nokia.com>
Signed-off-by: Éric Piel <eric.piel@tremplin-utc.net>
Signed-off-by: Samu Onkalo <samu.p.onkalo@nokia.com>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Most of the documentation and comments were written when the driver was
only supporting one type of chip, only via ACPI/HP. Update the info to
the much clearer understanding that we have now.
Signed-off-by: Éric Piel <eric.piel@tremplin-utc.net>
Signed-off-by: Samu Onkalo <samu.p.onkalo@nokia.com>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

polled input device itself was not free'd.
Signed-off-by: Samu Onkalo <samu.p.onkalo@nokia.com>
Tested-by: Éric Piel <eric.piel@tremplin-utc.net>
Acked-by: Éric Piel <eric.piel@tremplin-utc.net>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Send input_sync after each measurement round. This helps userspace to
detect which reported values belongs to the same measurement.
Signed-off-by: Samu Onkalo <samu.p.onkalo@nokia.com>
Tested-by: Éric Piel <eric.piel@tremplin-utc.net>
Acked-by: Éric Piel <eric.piel@tremplin-utc.net>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>