There were a few files in the driver core power code that did not have
SPDX identifiers on them, so fix that up.  At the same time, remove the
"free form" text that specified the license of the file, as that is
impossible for any tool to properly parse.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Lockdep warns that prepare_lock and genpd->mlock can cause a deadlock
the deadlock scenario is like following:
First thread is probing cs2000
cs2000_probe()
  clk_register()
    __clk_core_init()
      clk_prepare_lock()                            ----> acquires prepare_lock
        cs2000_recalc_rate()
          i2c_smbus_read_byte_data()
            rcar_i2c_master_xfer()
              dma_request_chan()
                rcar_dmac_of_xlate()
                  rcar_dmac_alloc_chan_resources()
                    pm_runtime_get_sync()
                      __pm_runtime_resume()
                        rpm_resume()
                          rpm_callback()
                            genpd_runtime_resume()   ----> acquires genpd->mlock

Second thread is attaching any device to the same PM domain
genpd_add_device()
  genpd_lock()                                       ----> acquires genpd->mlock
    cpg_mssr_attach_dev()
      of_clk_get_from_provider()
        __of_clk_get_from_provider()
          __clk_create_clk()
            clk_prepare_lock()                       ----> acquires prepare_lock

Since currently no PM provider access genpd's critical section
in .attach_dev, and .detach_dev callbacks, so there is no need to protect
these two callbacks with genpd->mlock.
This patch avoids a potential deadlock by moving out .attach_dev and .detach_dev
from genpd->mlock, so that genpd->mlock won't be held when prepare_lock is acquired
in .attach_dev and .detach_dev
Signed-off-by: NJiada Wang <jiada_wang@mentor.com>
Reviewed-by: NUlf Hansson <ulf.hansson@linaro.org>
Tested-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

After commit d856f39ac1cc ("PM / wakeup: Rework wakeup source timer
cancellation") wakeup_source_drop() is a trivial wrapper around
__pm_relax() and it has no users except for wakeup_source_destroy()
and wakeup_source_trash() which also has no users, so drop it along
with the latter and make wakeup_source_destroy() call __pm_relax()
directly.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>

If wakeup_source_add() is called right after wakeup_source_remove()
for the same wakeup source, timer_setup() may be called for a
potentially scheduled timer which is incorrect.

To avoid that, move the wakeup source timer cancellation from
wakeup_source_drop() to wakeup_source_remove().

Moreover, make wakeup_source_remove() clear the timer function after
canceling the timer to let wakeup_source_not_registered() treat
unregistered wakeup sources in the same way as the ones that have
never been registered.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Cc: 4.4+ <stable@vger.kernel.org> # 4.4+
[ rjw: Subject, changelog, merged two patches together ]
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Remove one unnecessary blank line
Signed-off-by: NDong Aisheng <aisheng.dong@nxp.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

It is strange to only return early for -EBUSY state and left other
errors to be still measured execution time.

As for error cases, the elapsed_ns computed actually is not quite
accurate and meaningful for governor to use. So let's simply return
for all error cases.
Signed-off-by: NDong Aisheng <aisheng.dong@nxp.com>
Reviewed-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

It's possible a PM domain defines only one state and it does not need
a governor to work. For such case, a warning actually is not necessary.
Signed-off-by: NDong Aisheng <aisheng.dong@nxp.com>
Reviewed-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Fix a typo in the file description comment.
Signed-off-by: NDong Aisheng <aisheng.dong@nxp.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Avoid the open-coding of the accounted time acquisition in
runtime_active|suspend_time_show() and make them call
pm_runtime_active|suspended_time() instead.

Note that this change also indirectly avoids holding dev->power.lock
around the do_div() computation and the sprintf() call which is an
additional improvement.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
[ rjw: Changelog ]
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

In a step to consolidate the code for fetching the PM-runtime
active/suspended time for a device, add a common function for that
and make the existing pm_runtime_suspended_time() call it.

Also add a corresponding pm_runtime_active_time() calling the new
common function.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
[ rjw: Changelog, function rename ]
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Prefix all printk/pr_<level> messages with "PM: " to make the
logging a bit more consistent.

Miscellanea:

 o Convert a few printks to pr_<level>
 o Whitespace to align to open parentheses
 o Remove embedded "PM: " from pr_debugs as pr_fmt adds it
Signed-off-by: NJoe Perches <joe@perches.com>
Reviewed-by: NKees Cook <keescook@chromium.org>
Reviewed-by: NKevin Hilman <khilman@baylibre.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

When rpm_resume() desactivates the autosuspend timer, it should only
try to cancel hrtimer but not wait for the handler to finish, because
both rpm_resume() and pm_suspend_timer_fn() take the power.lock.

A deadlock is possible as follows:

CPU0                              CPU1
rpm_resume()
  spin_lock_irqsave
                                  pm_suspend_timer_fn()
                                    spin_lock_irqsave
  pm_runtime_deactivate_timer()
    hrtimer_cancel()

It is sufficient to call hrtimer_try_to_cancel() from
pm_runtime_deactivate_timer(), because dev->power.timer_expires
reset to 0 by it, so use that function instead of hrtimer_cancel().

Fixes: 8234f673 ("PM-runtime: Switch autosuspend over to using hrtimers")
Reported-by: NSunzhaosheng Sun(Zhaosheng) <sunzhaosheng@hisilicon.com>
Signed-off-by: NVincent Guittot <vincent.guittot@linaro.org>
[ rjw: Changelog ]
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Commit 4c06c4e6 ("driver core: Fix possible supplier PM-usage
counter imbalance") introduced a regression that causes suppliers
to be suspended prematurely for device links added during consumer
driver probe if the initial PM-runtime status of the consumer is
"suspended" and the consumer is resumed after adding the link and
before pm_runtime_put_suppliers() is called.  In that case,
pm_runtime_put_suppliers() will drop the rpm_active refcount for
the link by one and (since rpm_active is equal to two after the
preceding consumer resume) the supplier's PM-runtime usage counter
will be decremented, which may cause the supplier to suspend even
though the consumer's PM-runtime status is "active".

For this reason, partially revert commit 4c06c4e6 as the problem
it tried to fix needs to be addressed somewhat differently, and
change pm_runtime_get_suppliers() and pm_runtime_put_suppliers() so
that the latter only drops rpm_active references acquired by the
former.  [This requires adding a new field to struct device_link,
but I coulnd't find a cleaner way to address the issue that would
work in all cases.]

This causes pm_runtime_put_suppliers() to effectively ignore device
links added during consumer probe, so device_link_add() doesn't need
to worry about ensuring that suppliers will remain active after
pm_runtime_put_suppliers() for links created with DL_FLAG_RPM_ACTIVE
set and it only needs to bump up rpm_active by one for those links,
so pm_runtime_active_link() is not necessary any more.

Fixes: 4c06c4e6 ("driver core: Fix possible supplier PM-usage counter imbalance")
Reported-by: NJon Hunter <jonathanh@nvidia.com>
Tested-by: NJon Hunter <jonathanh@nvidia.com>
Tested-by: NUlf Hansson <ulf.hansson@linaro.org>
Reviewed-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: NThierry Reding <treding@nvidia.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

All device objects in the driver model contain fields that control the
handling of various power management activities. However, it's not
always useful. There are few instances where pseudo devices are added
to the model just to take advantage of many other features like
kobjects, udev events, and so on. One such example is cpu devices and
their caches.

The sysfs for the cpu caches are managed by adding devices with cpu
as the parent in cpu_device_create() when secondary cpu is brought
online. Generally when the secondary CPUs are hotplugged back in as part
of resume from suspend-to-ram, we call cpu_device_create() from the cpu
hotplug state machine while the cpu device associated with that CPU is
not yet ready to be resumed as the device_resume() call happens bit
later. It's not really needed to set the flag is_prepared for cpu
devices as they are mostly pseudo device and hotplug framework deals
with state machine and not managed through the cpu device.

This often results in annoying warning when resuming:
Enabling non-boot CPUs ...
CPU1: Booted secondary processor
 cache: parent cpu1 should not be sleeping
CPU1 is up
CPU2: Booted secondary processor
 cache: parent cpu2 should not be sleeping
CPU2 is up
.... and so on.

So in order to fix these kind of errors, we could just completely avoid
doing any power management related initialisations and operations if
they are not used by these devices.

Add no_pm flags to indicate that the device doesn't require any sort of
PM activities and all of them can be completely skipped. We can use the
same flag to also avoid adding not used *power* sysfs entries for these
devices. For now, lets use this for cpu cache devices.
Reviewed-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NSudeep Holla <sudeep.holla@arm.com>
Tested-by: NEugeniu Rosca <erosca@de.adit-jv.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

As of the patch ("PM / Domains: Mark "name" const in
genpd_dev_pm_attach_by_name()") it's clear that the name in
dev_pm_domain_attach_by_name() can be const.  Mark it as so.  This
allows drivers to pass in a name that was declared "const" in a
driver.

Fixes: 27dceb81 ("PM / Domains: Introduce dev_pm_domain_attach_by_name()")
Signed-off-by: NDouglas Anderson <dianders@chromium.org>
Reviewed-by: NStephen Boyd <swboyd@chromium.org>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The genpd_dev_pm_attach_by_name() simply takes the name and passes it
to of_property_match_string() where the argument is "const char *".
Adding a const here allows a later patch to add a const to
dev_pm_domain_attach_by_name() which allows drivers to pass in a name
that was declared "const" in a driver.

Fixes: 5d6be70a ("PM / Domains: Introduce option to attach a device by name to genpd")
Signed-off-by: NDouglas Anderson <dianders@chromium.org>
Reviewed-by: NStephen Boyd <swboyd@chromium.org>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Devices using the direct-complete optimization are not present it
debug messages printed by the core device suspend and resume code,
which sometimes makes it difficult to diagnose problems related to
them, so add debug messages for those devices.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

If a stateless device link to a certain supplier with
DL_FLAG_PM_RUNTIME set in the flags is added and then removed by the
consumer driver's probe callback, the supplier's PM-runtime usage
counter will be nonzero after that which effectively causes the
supplier to remain "always on" going forward.

Namely, device_link_add() called to add the link invokes
device_link_rpm_prepare() which notices that the consumer driver is
probing, so it increments the supplier's PM-runtime usage counter
with the assumption that the link will stay around until
pm_runtime_put_suppliers() is called by driver_probe_device(),
but if the link goes away before that point, the supplier's
PM-runtime usage counter will remain nonzero.

To prevent that from happening, first rework pm_runtime_get_suppliers()
and pm_runtime_put_suppliers() to use the rpm_active refounts of device
links and make the latter only drop rpm_active and the supplier's
PM-runtime usage counter for each link by one, unless rpm_active is
one already for it.  Next, modify device_link_add() to bump up the
new link's rpm_active refcount and the suppliers PM-runtime usage
counter by two, to prevent pm_runtime_put_suppliers(), if it is
called subsequently, from suspending the supplier prematurely (in
case its PM-runtime usage counter goes down to 0 in there).

Due to the way rpm_put_suppliers() works, this change does not
affect runtime suspend of the consumer ends of new device links (or,
generally, device links for which DL_FLAG_PM_RUNTIME has just been
set).

Fixes: e2f3cd83 ("driver core: Fix handling of runtime PM flags in device_link_add()")
Reported-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: NUlf Hansson <ulf.hansson@linaro.org>
Tested-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Commit 4080ab08 ("PM-runtime: Take suppliers into account in
__pm_runtime_set_status()") introduced a race condition that may
trigger if __pm_runtime_set_status() is used incorrectly (that is,
if it is called when PM-runtime is enabled for the target device
and working).

In that case, if the original PM-runtime status of the device is
RPM_SUSPENDED, a runtime resume of the device may occur after
__pm_runtime_set_status() has dropped its power.lock spinlock
and before deactivating its suppliers, so the suppliers may be
deactivated while the device is PM-runtime-active which may lead
to functional issues.

To avoid that, modify __pm_runtime_set_status() to check whether
or not PM-runtime is enabled for the device before activating its
suppliers (if the new status is RPM_ACTIVE) and either return an
error if that's the case or increment the device's disable_depth
counter to prevent PM-runtime from being enabled for it while
the remaining part of the function is running (disable_depth is
then decremented on the way out).

Fixes: 4080ab08 ("PM-runtime: Take suppliers into account in __pm_runtime_set_status()")
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

If the target device has any suppliers, as reflected by device links
to them, __pm_runtime_set_status() does not take them into account,
which is not consistent with the other parts of the PM-runtime
framework and may lead to programming mistakes.

Modify __pm_runtime_set_status() to take suppliers into account by
activating them upfront if the new status is RPM_ACTIVE and
deactivating them on exit if the new status is RPM_SUSPENDED.

If the activation of one of the suppliers fails, the new status
will be RPM_SUSPENDED and the (remaining) suppliers will be
deactivated on exit (the child count of the device's parent
will be dropped too then).

Of course, adding device links locking to __pm_runtime_set_status()
means that it cannot be run fron interrupt context, so make it use
spin_lock_irq() and spin_unlock_irq() instead of spin_lock_irqsave()
and spin_unlock_irqrestore(), respectively.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Update the accounting_timestamp field only when PM runtime is enabled
and don't forget to account the last state before disabling it.
Suggested-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NVincent Guittot <vincent.guittot@linaro.org>
Reviewed-by: NUlf Hansson <ulf.hansson@linaro.org>
[ rjw: Minor cleanups ]
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Similar to what happened whith autosuspend, a deadlock has been
reported with PM-runtime accounting in the call path:

change_clocksource
    ...
    write_seqcount_begin
    ...
    timekeeping_update
        ...
        sh_cmt_clocksource_enable
            ...
            rpm_resume
                update_pm_runtime_accounting
                    ktime_get
                        do
                            read_seqcount_begin
                        while read_seqcount_retry
    ....
    write_seqcount_end

Make PM-runtime accounting use ktime_get_mono_fast_ns() to avoid this
problem.

With ktime_get_mono_fast_ns(), the timestamp is not guaranteed to be
monotonic across an update of timekeeping and as a result time can go
backward. Add a test to skip accounting for such situation which should
stay exceptional.

Fixes: a08c2a5a ("PM-runtime: Replace jiffies-based accounting with ktime-based accounting")
Reported-by: NBiju Das <biju.das@bp.renesas.com>
Signed-off-by: NVincent Guittot <vincent.guittot@linaro.org>
Reviewed-by: NUlf Hansson <ulf.hansson@linaro.org>
[ rjw: Subject, changelog, comment cleanup ]
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

pm_runtime_autosuspend_expiration calls ktime_get_mono_fast_ns()
even when its returned value may be unused. Therefore get the
current time later and remove gotos while there.
Signed-off-by: NLadislav Michl <ladis@linux-mips.org>
Acked-by: NTony Lindgren <tony@atomide.com>
Acked-by: NVincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Calling rpm_put_suppliers() from pm_runtime_drop_link() is excessive
as it affects all suppliers of the consumer device and not just the
one pointed to by the device link being dropped.  Worst case it may
cause the consumer device to stop working unexpectedly.  Moreover, in
principle it is racy with respect to runtime PM of the consumer
device.

To avoid these problems drop runtime PM references on the particular
supplier pointed to by the link in question only and do that after
the link has been dropped from the consumer device's list of links to
suppliers, which is in device_link_free().

Fixes: a0504aec ("PM / runtime: Drop usage count for suppliers at device link removal")
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

After commit ead18c23 ("driver core: Introduce device links
reference counting"), if there is a link between the given supplier
and the given consumer already, device_link_add() will refcount it
and return it unconditionally without updating its flags.  It is
possible, however, that the second (or any subsequent) caller of
device_link_add() for the same consumer-supplier pair will pass
DL_FLAG_PM_RUNTIME, possibly along with DL_FLAG_RPM_ACTIVE, in flags
to it and the existing link may not behave as expected then.

First, if DL_FLAG_PM_RUNTIME is not set in the existing link's flags
at all, it needs to be set like during the original initialization of
the link.

Second, if DL_FLAG_RPM_ACTIVE is passed to device_link_add() in flags
(in addition to DL_FLAG_PM_RUNTIME), the existing link should to be
updated to reflect the "active" runtime PM configuration of the
consumer-supplier pair and extra care must be taken here to avoid
possible destructive races with runtime PM of the consumer.

To that end, redefine the rpm_active field in struct device_link
as a refcount, initialize it to 1 and make rpm_resume() (for the
consumer) and device_link_add() increment it whenever they acquire
a runtime PM reference on the supplier device.  Accordingly, make
rpm_suspend() (for the consumer) and pm_runtime_clean_up_links()
decrement it and drop runtime PM references to the supplier
device in a loop until rpm_active becones 1 again.

Fixes: ead18c23 ("driver core: Introduce device links reference counting")
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Use the device specific version of the async_schedule commands to defer
various tasks related to power management. By doing this we should see a
slight improvement in performance as any device that is sensitive to
latency/locality in the setup will now be initializing on the node closest
to the device.
Reviewed-by: NDan Williams <dan.j.williams@intel.com>
Reviewed-by: NBart Van Assche <bvanassche@acm.org>
Reviewed-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: NAlexander Duyck <alexander.h.duyck@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Replace jiffies-based accounting for runtime_active_time and
runtime_suspended_time with ktime-based accounting. This makes the
runtime debug counters inline with genpd and other PM subsytems which
use ktime-based accounting.

Timekeeping is initialized before driver_init(). It's only at that time
that PM-runtime can be enabled.
Signed-off-by: NThara Gopinath <thara.gopinath@linaro.org>
[switch from ktime to raw nsec]
Signed-off-by: NVincent Guittot <vincent.guittot@linaro.org>
Reviewed-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Initializing accounting_timestamp to something different from 0 during
pm_runtime_init() doesn't make sense and puts an artificial ordering
constraint between timekeeping_init() and pm_runtime_init().

PM-runtime should start time accounting only when it is enabled and
discard the period when disabled.

Set accounting_timestamp to now when enabling PM-runtime.
Suggested-by: N"Rafael J. Wysocki" <rjw@rjwysocki.net>
Signed-off-by: NVincent Guittot <vincent.guittot@linaro.org>
Reviewed-by: NUlf Hansson <ulf.hansson@linaro.org>
[ rjw: Subject & changelog ]
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

A deadlock has been seen when swicthing clocksources which use
PM-runtime.  The call path is:

change_clocksource
    ...
    write_seqcount_begin
    ...
    timekeeping_update
        ...
        sh_cmt_clocksource_enable
            ...
            rpm_resume
                pm_runtime_mark_last_busy
                    ktime_get
                        do
                            read_seqcount_begin
                        while read_seqcount_retry
    ....
    write_seqcount_end

Although we should be safe because we haven't yet changed the
clocksource at that time, we can't do that because of seqcount
protection.

Use ktime_get_mono_fast_ns() instead which is lock safe for such
cases.

With ktime_get_mono_fast_ns, the timestamp is not guaranteed to be
monotonic across an update and as a result can goes backward.
According to update_fast_timekeeper() description: "In the worst
case, this can result is a slightly wrong timestamp (a few
nanoseconds)". For PM-runtime autosuspend, this means only that
the suspend decision may be slightly suboptimal.

Fixes: 8234f673 ("PM-runtime: Switch autosuspend over to using hrtimers")
Reported-by: NBiju Das <biju.das@bp.renesas.com>
Signed-off-by: NVincent Guittot <vincent.guittot@linaro.org>
Reviewed-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

This brings the kernel doc in line with the function signature.
Signed-off-by: NYangtao Li <tiny.windzz@gmail.com>
Acked-by: NPavel Machek <pavel@ucw.cz>
[ rjw: Subject ]
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

When calling debugfs functions, there is no need to ever check the
return value.  The function can work or not, but the code logic should
never do something different based on this.
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

clk_prepare() can fail, so check its status and if it fails,
issue an error message and change the clock_entry_status to
PCE_STATUS_ERROR.
Signed-off-by: NAditya Pakki <pakki001@umn.edu>
[ rjw: Subject ]
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Some drivers (like i915/drm) needs to get the accounted suspended time.
pm_runtime_suspended_time() will return the suspended accounted time
in ns unit.
Reviewed-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NVincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Cast autosuspend_delay to u64 to make sure that the full computation
of 'expires' or slack will be done in u64, even on 32bits arch.

Otherwise, any delay greater than 2^31 nsec can overflow if signed
32bits is used when converting delay from msec to nsec.

Fixes: 8234f673 (PM-runtime: Switch autosuspend over to using hrtimers)
Reported-by: NTony Lindgren <tony@atomide.com>
Tested-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NVincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

PM-runtime now uses the hrtimers infrastructure for autosuspend, however
comments still reference 'jiffies'.

Fixes: 8234f673 (PM-runtime: Switch autosuspend over to using hrtimers)
Signed-off-by: NLadislav Michl <ladis@linux-mips.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Devfreq framework supports suspend of its devices.
Call the the devfreq interface and allow devfreq devices
preserve/restore their states during suspend/resume.
Suggested-by: NTobias Jakobi <tjakobi@math.uni-bielefeld.de>
Reviewed-by: NChanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: NLukasz Luba <l.luba@partner.samsung.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

We already have the DEFINE_SHOW_ATTRIBUTE, There is no need to define
such a macro, so remove define_genpd_open_function and
define_genpd_debugfs_fops.

Convert them to DEFINE_SHOW_ATTRIBUTE.
Signed-off-by: NYangtao Li <tiny.windzz@gmail.com>
Acked-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

PM-runtime uses the timer infrastructure for autosuspend. This implies
that the minimum time before autosuspending a device is in the range
of 1 tick included to 2 ticks excluded
 -On arm64 this means between 4ms and 8ms with default jiffies
  configuration
 -And on arm, it is between 10ms and 20ms

These values are quite high for embedded systems which sometimes want
the duration to be in the range of 1 ms.

It is possible to switch autosuspend over to using hrtimers to get
finer granularity for short durations and take advantage of slack to
retain some margins and get long timeouts with minimum wakeups.

On an arm64 platform that uses 1ms for autosuspending timeout of its
GPU, idle power is reduced by 10% with hrtimer.

The latency impact on arm64 hikey octo cores is:
 - mark_last_busy: from 1.11 us to 1.25 us
 - rpm_suspend: from 15.54 us to 15.38 us
[Only the code path of rpm_suspend() that starts hrtimer has been
measured.]

arm64 image (arm64 default defconfig) decreases by around 3KB
with following details:

$ size vmlinux-timer
   text	   data	    bss	    dec	    hex	filename
12034646	6869268	 386840	19290754	1265a82	vmlinux

$ size vmlinux-hrtimer
   text	   data	    bss	    dec	    hex	filename
12030550	6870164	 387032	19287746	1264ec2	vmlinux

The latency impact on arm 32bits snowball dual cores is :
 - mark_last_busy: from 0.31 us usec to 0.77 us
 - rpm_suspend: from 6.83 us to 6.67 usec

The increase of the image for snowball platform that I used for
testing performance impact, is neglictable (244B).

$ size vmlinux-timer
   text	   data	    bss	    dec	    hex	filename
7157961	2119580	 264120	9541661	 91981d	build-ux500/vmlinux

size vmlinux-hrtimer
   text	   data	    bss	    dec	    hex	filename
7157773	21198846	 264248	9541905	 919911	vmlinux-hrtimer

And arm 32bits image (multi_v7_defconfig) increases by around 1.7KB
with following details:

$ size vmlinux-timer
   text	   data	    bss	    dec	    hex	filename
13304443	6803420	 402768	20510631	138f7a7	vmlinux

$ size vmlinux-hrtimer
   text	   data	    bss	    dec	    hex	filename
13304299	6805276	 402768	20512343	138fe57	vmlinux
Signed-off-by: NVincent Guittot <vincent.guittot@linaro.org>
Reviewed-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Currently a genpd only handles the performance state requirements from
the devices under its control. This commit extends that to also handle
the performance state requirement(s) put on the master genpd by its
sub-domains. There is a separate value required for each master that
the genpd has and so a new field is added to the struct gpd_link
(link->performance_state), which represents the link between a genpd and
its master. The struct gpd_link also got another field
prev_performance_state, which is used by genpd core as a temporary
variable during transitions.

On a call to dev_pm_genpd_set_performance_state(), the genpd core first
updates the performance state of the masters of the device's genpd and
then updates the performance state of the genpd. The masters do the same
and propagate performance state updates to their masters before updating
their own. The performance state transition from genpd to its master is
done with the help of dev_pm_opp_xlate_performance_state(), which looks
at the OPP tables of both the domains to translate the state.
Tested-by: NRajendra Nayak <rnayak@codeaurora.org>
Reviewed-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>

Separate out _genpd_set_performance_state() and
_genpd_reeval_performance_state() from
dev_pm_genpd_set_performance_state() to handle performance state update
related stuff. This will be used by a later commit.
Tested-by: NRajendra Nayak <rnayak@codeaurora.org>
Reviewed-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>