While resuming a device belonging to a PM domain,
pm_genpd_runtime_resume() calls __pm_genpd_restore_device() to
restore its state, if necessary.  The latter starts the device,
using genpd_start_dev(), restores its state, using
genpd_restore_dev(), and then stops it, using genpd_stop_dev().
However, this last operation is not necessary, because the
device is supposed to be operational after pm_genpd_runtime_resume()
has returned and because of it pm_genpd_runtime_resume() has to
call genpd_start_dev() once again for the "restored" device, which
is inefficient.

To make things more efficient, remove the call to genpd_stop_dev()
from __pm_genpd_restore_device() and the direct call to
genpd_start_dev() from pm_genpd_runtime_resume().  [Of course,
genpd_start_dev() still has to be called by it for devices with the
power.irq_safe flag set, because __pm_genpd_restore_device() is not
executed for them.]

This change has been tested on the SH7372 Mackerel board.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

Currently, the default "save state" and "restore state" routines
for generic PM domains, pm_genpd_default_save_state() and
pm_genpd_default_restore_state(), respectively, only use runtime PM
callbacks provided by device drivers, but in general those callbacks
need not provide the entire necessary functionality.  Namely, in
general it may be necessary to execute subsystem (i.e. device type,
device class or bus type) callbacks that will carry out all of the
necessary operations.

For this reason, modify pm_genpd_default_save_state() and
pm_genpd_default_restore_state() to execute subsystem callbacks,
if they are provided, and fall back to driver callbacks otherwise.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

__device_suspend() must always send a completion. Otherwise, parent
devices will wait forever.

Commit 1e2ef05b, "PM: Limit race conditions between runtime PM and
system sleep (v2)", introduced a regression by short-circuiting the
complete_all() for certain error cases.

This patch fixes the bug by always signalling a completion.

Addresses http://crosbug.com/31972

Tested by injecting an abort.
Signed-off-by: NMandeep Singh Baines <msb@chromium.org>
Cc: stable@vger.kernel.org
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

If driver requests probe deferral,
it will be added to deferred_probe_pending_list
by driver_deferred_probe_add(), but, it used list_add().
Because of that, deferred probe will be run as reversed order.
This patch uses list_add_tail(), and solved this issue.
Signed-off-by: NKuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

It's supposed to be there for drivers.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

The word to be transmitted/received via regmap is composed by the following
parts:

config->reg_bits
config->val_bits
config->pad_bits

,so the total size should be calculated by summing up the number of bits of
each element and using a DIV_ROUND_UP to return the number of bytes.
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

If debugfs isn't cleaned up, stale files will be left in the filesystem
which will cause an OOPS when accessed the first time, and hang the
accessing application when accessed again, presumably due to some lock
being left held.
Signed-off-by: NStephen Warren <swarren@nvidia.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Since there are uses for I2C_M_NOSTART which are much more sensible and
standard than most of the protocol mangling functionality (the main one
being gather writes to devices where something like a register address
needs to be inserted before a block of data) create a new I2C_FUNC_NOSTART
for this feature and update all the users to use it.

Also strengthen the disrecommendation of the protocol mangling while we're
at it.

In the case of regmap-i2c we remove the requirement for mangling as
I2C_M_NOSTART is the only mangling feature which is being used.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: NWolfram Sang <w.sang@pengutronix.de>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

/sys/devices/system/node/{online,possible} outputs a garbage byte
because print_nodes_state() returns content size + 1.  To fix the bug,
the patch changes the use of cpuset_sprintf_cpulist to follow the use at
other places, which is clearer and safer.

This bug was introduced in v2.6.24 (commit bde631a5: "mm: add node
states sysfs class attributeS").
Signed-off-by: NRyota Ozaki <ozaki.ryota@gmail.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Some minor inline documentation fixes for gaps resulting from new patches.
Signed-off-by: NSumit Semwal <sumit.semwal@ti.com>
Signed-off-by: NSumit Semwal <sumit.semwal@linaro.org>

The main requirement I have for this interface is for scanning out
using the USB gpu devices. Since these devices have to read the
framebuffer on updates and linearly compress it, using kmaps
is a major overhead for every update.

v2: fix warn issues pointed out by Sylwester Nawrocki.

v3: fix compile !CONFIG_DMA_SHARED_BUFFER and add _GPL for now
Signed-off-by: NDave Airlie <airlied@redhat.com>
Reviewed-by: NRob Clark <rob.clark@linaro.org>
Signed-off-by: NSumit Semwal <sumit.semwal@linaro.org>

Compared to Rob Clark's RFC I've ditched the prepare/finish hooks
and corresponding ioctls on the dma_buf file. The major reason for
that is that many people seem to be under the impression that this is
also for synchronization with outstanding asynchronous processsing.
I'm pretty massively opposed to this because:

- It boils down reinventing a new rather general-purpose userspace
  synchronization interface. If we look at things like futexes, this
  is hard to get right.
- Furthermore a lot of kernel code has to interact with this
  synchronization primitive. This smells a look like the dri1 hw_lock,
  a horror show I prefer not to reinvent.
- Even more fun is that multiple different subsystems would interact
  here, so we have plenty of opportunities to create funny deadlock
  scenarios.

I think synchronization is a wholesale different problem from data
sharing and should be tackled as an orthogonal problem.

Now we could demand that prepare/finish may only ensure cache
coherency (as Rob intended), but that runs up into the next problem:
We not only need mmap support to facilitate sw-only processing nodes
in a pipeline (without jumping through hoops by importing the dma_buf
into some sw-access only importer), which allows for a nicer
ION->dma-buf upgrade path for existing Android userspace. We also need
mmap support for existing importing subsystems to support existing
userspace libraries. And a loot of these subsystems are expected to
export coherent userspace mappings.

So prepare/finish can only ever be optional and the exporter /needs/
to support coherent mappings. Given that mmap access is always
somewhat fallback-y in nature I've decided to drop this optimization,
instead of just making it optional. If we demonstrate a clear need for
this, supported by benchmark results, we can always add it in again
later as an optional extension.

Other differences compared to Rob's RFC is the above mentioned support
for mapping a dma-buf through facilities provided by the importer.
Which results in mmap support no longer being optional.

Note that this dma-buf mmap patch does _not_ support every possible
insanity an existing subsystem could pull of with mmap: Because it
does not allow to intercept pagefaults and shoot down ptes importing
subsystems can't add some magic of their own at these points (e.g. to
automatically synchronize with outstanding rendering or set up some
special resources). I've done a cursory read through a few mmap
implementions of various subsytems and I'm hopeful that we can avoid
this (and the complexity it'd bring with it).

Additonally I've extended the documentation a bit to explain the hows
and whys of this mmap extension.

In case we ever want to add support for explicitly cache maneged
userspace mmap with a prepare/finish ioctl pair, we could specify that
userspace needs to mmap a different part of the dma_buf, e.g. the
range starting at dma_buf->size up to dma_buf->size*2. This works
because the size of a dma_buf is invariant over it's lifetime. The
exporter would obviously need to fall back to coherent mappings for
both ranges if a legacy clients maps the coherent range and the
architecture cannot suppor conflicting caching policies. Also, this
would obviously be optional and userspace needs to be able to fall
back to coherent mappings.

v2:
- Spelling fixes from Rob Clark.
- Compile fix for !DMA_BUF from Rob Clark.
- Extend commit message to explain how explicitly cache managed mmap
  support could be added later.
- Extend the documentation with implementations notes for exporters
  that need to manually fake coherency.

v3:
- dma_buf pointer initialization goof-up noticed by Rebecca Schultz
  Zavin.

Cc: Rob Clark <rob.clark@linaro.org>
Cc: Rebecca Schultz Zavin <rebecca@android.com>
Acked-by: NRob Clark <rob.clark@linaro.org>
Signed-Off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NSumit Semwal <sumit.semwal@linaro.org>

Ensure that we can't get randconfig breakage by doing the IRQ_DOMAIN
select automatically. Don't just do the select from REGMAP_IRQ to ensure
that the select actually gets noticed.
Reported-by: NRandy Dunlap <rdunlap@xenotime.net>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

The Contiguous Memory Allocator is a set of helper functions for DMA
mapping framework that improves allocations of contiguous memory chunks.

CMA grabs memory on system boot, marks it with MIGRATE_CMA migrate type
and gives back to the system. Kernel is allowed to allocate only movable
pages within CMA's managed memory so that it can be used for example for
page cache when DMA mapping do not use it. On
dma_alloc_from_contiguous() request such pages are migrated out of CMA
area to free required contiguous block and fulfill the request. This
allows to allocate large contiguous chunks of memory at any time
assuming that there is enough free memory available in the system.

This code is heavily based on earlier works by Michal Nazarewicz.
Signed-off-by: NMarek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: NMichal Nazarewicz <mina86@mina86.com>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Tested-by: NRob Clark <rob.clark@linaro.org>
Tested-by: NOhad Ben-Cohen <ohad@wizery.com>
Tested-by: NBenjamin Gaignard <benjamin.gaignard@linaro.org>
Tested-by: NRobert Nelson <robertcnelson@gmail.com>
Tested-by: NBarry Song <Baohua.Song@csr.com>

Add a common helper for dma-mapping core for mapping a coherent buffer
to userspace.
Reported-by: NSubash Patel <subashrp@gmail.com>
Signed-off-by: NMarek Szyprowski <m.szyprowski@samsung.com>
Acked-by: NKyungmin Park <kyungmin.park@samsung.com>
Tested-By: NSubash Patel <subash.ramaswamy@linaro.org>

The generic PM domains core code currently requires domains to be in
the "power on" state for adding devices to them, but this limitation
turns out to be inconvenient in some situations, so remove it.

For this purpose, make __pm_genpd_add_device() set the device's
need_restore flag if the domain is in the "power off" state, so that
the device's "restore state" (usually .runtime_resume()) callback
is executed when it is resumed after the domain has been turned on.
If the domain is in the "power on" state, the device's need_restore
flag will be cleared by __pm_genpd_add_device(), so that its "save
state" (usually .runtime_suspend()) callback is executed when the
domain is about to be turned off.  However, since that default
behavior need not be always desirable, add a helper function
pm_genpd_dev_need_restore() allowing a device's need_restore flag
to be set/unset at any time.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

It's been broken forever (i.e. it's not scheduling in a power
aware fashion), as reported by Suresh and others sending
patches, and nobody cares enough to fix it properly ...
so remove it to make space free for something better.

There's various problems with the code as it stands today, first
and foremost the user interface which is bound to topology
levels and has multiple values per level. This results in a
state explosion which the administrator or distro needs to
master and almost nobody does.

Furthermore large configuration state spaces aren't good, it
means the thing doesn't just work right because it's either
under so many impossibe to meet constraints, or even if
there's an achievable state workloads have to be aware of
it precisely and can never meet it for dynamic workloads.

So pushing this kind of decision to user-space was a bad idea
even with a single knob - it's exponentially worse with knobs
on every node of the topology.

There is a proposal to replace the user interface with a single
3 state knob:

 sched_balance_policy := { performance, power, auto }

where 'auto' would be the preferred default which looks at things
like Battery/AC mode and possible cpufreq state or whatever the hw
exposes to show us power use expectations - but there's been no
progress on it in the past many months.

Aside from that, the actual implementation of the various knobs
is known to be broken. There have been sporadic attempts at
fixing things but these always stop short of reaching a mergable
state.

Therefore this wholesale removal with the hopes of spurring
people who care to come forward once again and work on a
coherent replacement.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/1326104915.2442.53.camel@twinsSigned-off-by: NIngo Molnar <mingo@kernel.org>

In some chips the IRQ status registers are not contiguous in the register
map but spaced at even spaces. This is an easy case to handle with minor
changes. It is assume for this purpose that the stride for status is
equal to the stride for mask/ack registers as well.
Signed-off-by: NGraeme Gregory <gg@slimlogic.co.uk>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

driver_find_device() can be called with an unregistered driver. Need
to check driver_private to see if it's populated or not, especially
under deferrable probe.

In the case that there are 2 drivers, one depends on the other. With
-EPROBE_DEFER, two drivers can use deferred probe to ensure that their
relative probe order doesn't matter. If dependee driver is probed
first, then the dependant's driver_find_device('dependee')
succeeds. If the dependant is probed first, then the dependant's
driver_find_device('dependee') should return NULL, and the dependant
should get -EPROBE_DEFER. driver_find_device() needs to return NULL if
it's not populated.

In [PATCHv5 2/3] ARM: tegra: Add SMMU enabler in AHB:
  http://article.gmane.org/gmane.linux.ports.tegra/4658

"tegra_ahb_driver" may not be populated when it's called.

For more SMMU/AHB specific discussion, refer to the following thread:
  https://lkml.org/lkml/2012/5/10/21Signed-off-by: NHiroshi DOYU <hdoyu@nvidia.com>
Cc: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This gets us up to date with the recommended current kernel infrastructure
and should transparently give us device tree interrupt bindings for any
devices using the framework. If an explicit IRQ mapping is passed in then
a legacy interrupt range is created, otherwise a simple linear mapping is
used. Previously a mapping was mandatory so existing drivers should not
be affected.

A function regmap_irq_get_virq() is provided to allow drivers to map
individual IRQs which should be used in preference to the existing
regmap_irq_chip_get_base() which is only valid if a legacy IRQ range is
provided.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

It's needed for freeing and for obtaining the IRQ base later on.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

The default domain power off governor function for generic PM
domains, default_power_down_ok(), may violate subdomain maximum
off time limit by allowing the master domain to be off for too
long.  Namely, it only finds the minium of all device maximum
off times over the domain's devices and uses that to compute the
domain's maximum off time, but it should do the same for the
subdomains.

Fix this problem by modifying default_power_down_ok() to compute
the given domain's maximum off time as the difference between the
minimum off time over all devices and subdomains in the domain and
its power on latency.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

Current pm_genpd_add_subdomain() will allow duplicated link between
master and slave domain.  This patch fixed it.

Because when current pm_genpd_add_subdomain() checks whether the link
between the master and slave generic PM domain already exists,
slave_links instead of master_links of master domain is used.
Signed-off-by: NHuang Ying <ying.huang@intel.com>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

The function regmap_bulk_read() calls the regmap_read() for
each register if set of register has volatile and cache is
enabled. In this case, last few register read makes the memory
corruption if the register size is not the size of unsigned int.
The regam_read() takes argument as unsigned int for returning
value and it update the value as
	*val = map->format.parse_val(map->work_buf);
This causes complete 4 bytes (size of unsigned int) to get written.
Now if client pass the memory pointer for value which is equal to the
required size of register count in regmap_bulk_read() then last few
register read actually update the memory beyond passed pointer size.

Avoid this by using local variable for read and then do memcpy()
for actual byte copy to passed pointer based on register size.

I allocated one pointer ptr and take first 16 bytes dump of that
pointer then call regmap_bulk_read() with pointer which is just
on top of this allocated pointer and register count of 128. Here
register size is 1 byte.
The memory trace of last 5 register read are as follows:

[    5.438589] regmap_bulk_read after regamp_read() for register 122
[    5.447421] 0xef993c20 0xef993c00 0x00000000 0x00000001
[    5.467535] regmap_bulk_read after regamp_read() for register 123
[    5.476374] 0xef993c20 0xef993c00 0x00000000 0x00000001
[    5.496425] regmap_bulk_read after regamp_read() for register 124
[    5.505260] 0xef993c20 0xef993c00 0x00000000 0x00000001
[    5.525372] regmap_bulk_read after regamp_read() for register 125
[    5.534205] 0xef993c00 0xef993c00 0x00000000 0x00000001
[    5.554258] regmap_bulk_read after regamp_read() for register 126
[    5.563100] 0xef990000 0xef993c00 0x00000000 0x00000001
[    5.554258] regmap_bulk_read after regamp_read() for register 127
[    5.587108] 0xef000000 0xef993c00 0x00000000 0x00000001

Here it is observed that the memory content at first word started changing
on last 3 regmap_read() and so corruption happened.
Signed-off-by: NLaxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Use devres to implement dev_get_regmap(). This should mean that in almost
all cases devices wishing to take advantage of framework features based on
regmap shouldn't need to explicitly pass the regmap into the framework.
This simplifies device setup a bit.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Extends dev_printk() to attach a dictionary with a device identifier
and the driver core subsystem name to logged messages, which makes
dev_prink() reliable machine-readable. In addition to the printed
plain text message, it creates these properties:
    SUBSYSTEM=     - the driver-core subsytem name
    DEVICE=
      b12:8        - block dev_t
      c127:3       - char dev_t
      n8           - netdev ifindex
      +sound:card0 - subsystem:devname
Tested-by: NWilliam Douglas <william.douglas@intel.com>
Signed-off-by: NKay Sievers <kay@vrfy.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The results of the default device stop and domain power off governor
functions for generic PM domains, default_stop_ok() and
default_power_down_ok(), depend only on the timing data of devices,
which are static, and on their PM QoS constraints.  Thus, in theory,
these functions only need to carry out their computations, which may
be time consuming in general, when it is known that the PM QoS
constraint of at least one of the devices in question has changed.

Use the PM QoS notifiers of devices to implement that.  First,
introduce new fields, constraint_changed and max_off_time_changed,
into struct gpd_timing_data and struct generic_pm_domain,
respectively, and register a PM QoS notifier function when adding
a device into a domain that will set those fields to 'true' whenever
the device's PM QoS constraint is modified.  Second, make
default_stop_ok() and default_power_down_ok() use those fields to
decide whether or not to carry out their computations from scratch.

The device and PM domain hierarchies are taken into account in that
and the expense is that the changes of PM QoS constraints of
suspended devices will not be taken into account immediately, which
isn't guaranteed anyway in general.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

The removal of a device from a PM domain doesn't have to browse
the domain's device list, because it can check directly if the
device belongs to the given domain.  Moreover, it should clear
the domain_data pointer in dev->power.subsys_data, because
dev_pm_put_subsys_data(dev) may not remove dev->power.subsys_data
and the stale domain data pointer may cause problems to happen.

Rework pm_genpd_remove_device() taking the above observations into
account.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

APIs using devres frequently want to implement a "remove and free the
resource" operation so it seems sensible that they should be able to
just have devres do the freeing for them since that's a big part of what
devres is all about.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

It's not massively obvious (at least to me) that removing and freeing a
resource does not involve calling the release function for the resource
but rather only removes the management of it. Make the documentation more
explicit.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The current behavior of dev_pm_qos_add_notifier() makes device PM QoS
notifiers less than useful.  Namely, it silently returns success when
called before any PM QoS constraints are added for the device, so the
caller will assume that the notifier has been registered, but when
someone actually adds some nontrivial constraints for the device
eventually, the previous callers of dev_pm_qos_add_notifier()
will not know about that and their notifier routines will not be
executed (contrary to their expectations).

To address this problem make dev_pm_qos_add_notifier() create the
constraints object for the device if it is not present when the
routine is called.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Acked-by : markgross <markgross@thegnar.org>

After the previous changes in default_stop_ok() and
default_power_down_ok() for PM domains, there are two fields in
struct dev_pm_info that aren't necessary any more,  suspend_time
and max_time_suspended_ns.

Remove those fields along with all of the code that accesses them,
which simplifies the runtime PM framework quite a bit.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

The existing default domain power down governor function for PM
domains, default_power_down_ok(), is supposed to check whether or not
the PM QoS latency constraints of the devices in the domain will be
violated if the domain is turned off by pm_genpd_poweroff().
However, the computations carried out by it don't reflect the
definition of the PM QoS latency constrait in
Documentation/ABI/testing/sysfs-devices-power.

Make default_power_down_ok() follow the definition of the PM QoS
latency constrait.  In particular, make it only take latencies into
account, because it doesn't matter how much time has elapsed since
the domain's devices were suspended for the computation.

Remove the break_even_ns and power_off_time fields from
struct generic_pm_domain, because they are not necessary any more.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

The existing default device stop governor function for PM domains,
default_stop_ok(), is supposed to check whether or not the device's
PM QoS latency constraint will be violated if the device is stopped
by pm_genpd_runtime_suspend().  However, the computations carried out
by it don't reflect the definition of the PM QoS latency constrait in
Documentation/ABI/testing/sysfs-devices-power.

Make default_stop_ok() follow the definition of the PM QoS latency
constrait.  In particular, make it take the device's start and stop
latencies correctly.

Add a new field, effective_constraint_ns, to struct gpd_timing_data
and use it to store the difference between the device's PM QoS
constraint and its resume latency for use by the device's parent
(the effective_constraint_ns values for the children are used for
computing the parent's one along with its PM QoS constraint).

Remove the break_even_ns field from struct gpd_timing_data, because
it's not used any more.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

Android allows user space to manipulate wakelocks using two
sysfs file located in /sys/power/, wake_lock and wake_unlock.
Writing a wakelock name and optionally a timeout to the wake_lock
file causes the wakelock whose name was written to be acquired (it
is created before is necessary), optionally with the given timeout.
Writing the name of a wakelock to wake_unlock causes that wakelock
to be released.

Implement an analogous interface for user space using wakeup sources.
Add the /sys/power/wake_lock and /sys/power/wake_unlock files
allowing user space to create, activate and deactivate wakeup
sources, such that writing a name and optionally a timeout to
wake_lock causes the wakeup source of that name to be activated,
optionally with the given timeout.  If that wakeup source doesn't
exist, it will be created and then activated.  Writing a name to
wake_unlock causes the wakeup source of that name, if there is one,
to be deactivated.  Wakeup sources created with the help of
wake_lock that haven't been used for more than 5 minutes are garbage
collected and destroyed.  Moreover, there can be only WL_NUMBER_LIMIT
wakeup sources created with the help of wake_lock present at a time.

The data type used to track wakeup sources created by user space is
called "struct wakelock" to indicate the origins of this feature.

This version of the patch includes an rbtree manipulation fix from John Stultz.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: NNeilBrown <neilb@suse.de>

Android uses one wakelock statistics that is only necessary for
opportunistic sleep.  Namely, the prevent_suspend_time field
accumulates the total time the given wakelock has been locked
while "automatic suspend" was enabled.  Add an analogous field,
prevent_sleep_time, to wakeup sources and make it behave in a similar
way.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Introduce a mechanism by which the kernel can trigger global
transitions to a sleep state chosen by user space if there are no
active wakeup sources.

It consists of a new sysfs attribute, /sys/power/autosleep, that
can be written one of the strings returned by reads from
/sys/power/state, an ordered workqueue and a work item carrying out
the "suspend" operations.  If a string representing the system's
sleep state is written to /sys/power/autosleep, the work item
triggering transitions to that state is queued up and it requeues
itself after every execution until user space writes "off" to
/sys/power/autosleep.

That work item enables the detection of wakeup events using the
functions already defined in drivers/base/power/wakeup.c (with one
small modification) and calls either pm_suspend(), or hibernate() to
put the system into a sleep state.  If a wakeup event is reported
while the transition is in progress, it will abort the transition and
the "system suspend" work item will be queued up again.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: NNeilBrown <neilb@suse.de>

Add tracepoints to wakeup_source_activate and wakeup_source_deactivate.
Useful for checking that specific wakeup sources overlap as expected.
Signed-off-by: NArve Hjønnevåg <arve@android.com>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>