The special value of 0 for device resume latency PM QoS means
"no restriction", but there are two problems with that.

First, device resume latency PM QoS requests with 0 as the
value are always put in front of requests with positive
values in the priority lists used internally by the PM QoS
framework, causing 0 to be chosen as an effective constraint
value.  However, that 0 is then interpreted as "no restriction"
effectively overriding the other requests with specific
restrictions which is incorrect.

Second, the users of device resume latency PM QoS have no
way to specify that *any* resume latency at all should be
avoided, which is an artificial limitation in general.

To address these issues, modify device resume latency PM QoS to
use S32_MAX as the "no constraint" value and 0 as the "no
latency at all" one and rework its users (the cpuidle menu
governor, the genpd QoS governor and the runtime PM framework)
to follow these changes.

Also add a special "n/a" value to the corresponding user space I/F
to allow user space to indicate that it cannot accept any resume
latencies at all for the given device.

Fixes: 85dc0b8a (PM / QoS: Make it possible to expose PM QoS latency constraints)
Link: https://bugzilla.kernel.org/show_bug.cgi?id=197323Reported-by: NReinette Chatre <reinette.chatre@intel.com>
Tested-by: NReinette Chatre <reinette.chatre@intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NAlex Shi <alex.shi@linaro.org>
Cc: All applicable <stable@vger.kernel.org>

The notifier callbacks may want to call some OPP helper routines which
may try to take the same opp_table->lock again and cause a deadlock. One
such usecase was reported by Chanwoo Choi, where calling
dev_pm_opp_disable() leads us to the devfreq's OPP notifier handler,
which further calls dev_pm_opp_find_freq_floor() and it deadlocks.

We don't really need the opp_table->lock to be held across the notifier
call though, all we want to make sure is that the 'opp' doesn't get
freed while being used from within the notifier chain. We can do it with
help of dev_pm_opp_get/put() as well. Let's do it.

Cc: 4.11+ <stable@vger.kernel.org> # 4.11+
Fixes: 5b650b38 "PM / OPP: Take kref from _find_opp_table()"
Reported-by: NChanwoo Choi <cw00.choi@samsung.com>
Tested-by: NChanwoo Choi <cw00.choi@samsung.com>
Reviewed-by: NStephen Boyd <sboyd@codeaurora.org>
Reviewed-by: NChanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The device_pm_check_callbacks() function doesn't check legacy
->suspend and ->resume callback pointers under the device's
bus type, class and driver, so in some cases it may set the
no_pm_callbacks flag for the device incorrectly and then the
callbacks may be skipped during system suspend/resume, which
shouldn't happen.

Fixes: aa8e54b5 (PM / sleep: Go direct_complete if driver has no callbacks)
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: 4.5+ <stable@vger.kernel.org> # 4.5+

Use the actual function argument for the validation of the request type,
instead of the type field in a fresh (supposedly zero-initialized)
request structure.
Signed-off-by: NJan H. Schönherr <jschoenh@amazon.de>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Now that we have a custom printf format specifier, convert users of
full_name to use %pOF instead. This is preparation to remove storing
of the full path string for each node.
Signed-off-by: NRob Herring <robh@kernel.org>
Reviewed-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Acked-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Rename the freeze_state enum representing the suspend-to-idle state
machine states to s2idle_states and rename the related variables and
functions accordingly.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Currently, an error from wakeup_sysfs_add() in
device_set_wakeup_capable() causes the device's power.can_wakeup
flag to remain unset even though the device technically is capable
of signaling wakeup.

If wakeup_sysfs_add() fails user space may not be able to enable
the device to wake up the system from sleep states, but at least
for some devices that does not matter.

For this reason, set or clear power.can_wakeup upfront and if
wakeup_sysfs_add() returns an error, print a message to the log.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

We fail dev_pm_opp_of_get_sharing_cpus() when possible CPU device does
not exist. This can happen on platforms where not all possible CPUs
are available at start up ie. hotplugged out.  The CPU device is not
registered in the system so we are not able to check struct device to
set the sharing CPUs bitmask properly.

Example (real use case):
2 physical MIPS cores, 4 VPE, cpu0/2 run Linux and cpu1/3 are not
available for Linux at boot up. cpufreq-dt driver + OPP v2 fail to
register opp_table due to the fact there is no struct device for
cpu1 (remains offline at
bootup).

To solve the bug, stop using device struct to check device_node.
Instead get CPU device_node directly from device tree with
of_get_cpu_node().
Signed-off-by: NWaldemar Rymarkiewicz <waldemarx.rymarkiewicz@intel.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Restore the pm_wakeup_pending() check in __device_suspend_noirq()
removed by commit eed4d47e (ACPI / sleep: Ignore spurious SCI
wakeups from suspend-to-idle) as that allows the function to return
earlier if there's a wakeup event pending already (so that it may
spend less time on carrying out operations that will be reversed
shortly anyway) and rework the main suspend-to-idle loop to take
that optimization into account.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Make the core device suspend/resume code also call dpm_show_time()
on failures and add an error argument to this function so that the
message printed by it can reflect the success or failure condition.

This makes the debug messages in question look less confusing in
the failing cases.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Put the device interrupts disabling and enabling as well as
cpuidle_pause() and cpuidle_resume() called during the "noirq"
stages of system suspend into separate functions to allow the
core suspend-to-idle code to be optimized (later).

The only functional difference this makes is that debug facilities
and diagnostic tools will not include the above operations into the
"noirq" device suspend/resume duration measurements.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

This patch extends the existing generic power domain debugfs.
Changes involve the following
- Introduce a unique debugfs entry for each generic power domain with the
  following attributes
	- current_state - Displays current state of the domain.
	- devices - Displays the devices associated with this domain.
	- sub_domains - Displays the sub power domains.
	- active_time - Displays the time the domain was in active state
			in ms.
	- total_idle_time - Displays the time the domain was in any of the idle
			states in ms.
	- idle_states - Displays the various idle states and the time
			spent in each idle state in ms.
Signed-off-by: NThara Gopinath <thara.gopinath@linaro.org>
Acked-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

This patch adds support to calculate the time spent by the generic
power domains in on and various idle states.
Signed-off-by: NThara Gopinath <thara.gopinath@linaro.org>
Acked-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Debug messages from the system suspend/hibernation infrastructure can
fill up the entire kernel log buffer in some cases and anyway they
are only useful for debugging.  They depend on CONFIG_PM_DEBUG, but
that is set as a rule as some generally useful diagnostic facilities
depend on it too.

For this reason, avoid printing those messages by default, but make
it possible to turn them on as needed with the help of a new sysfs
attribute under /sys/power/.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

If the genpd->attach_dev or genpd->power_on fails, genpd_dev_pm_attach
may return -EPROBE_DEFER initially. However genpd_alloc_dev_data sets
the PM domain for the device unconditionally.

When subsequent attempts are made to call genpd_dev_pm_attach, it may
return -EEXISTS checking dev->pm_domain without re-attempting to call
attach_dev or power_on.

platform_drv_probe then attempts to call drv->probe as the return value
-EEXIST != -EPROBE_DEFER, which may end up in a situation where the
device is accessed without it's power domain switched on.

Fixes: f104e1e5 (PM / Domains: Re-order initialization of generic_pm_domain_data)
Cc: 4.4+ <stable@vger.kernel.org> # v4.4+
Signed-off-by: NSudeep Holla <sudeep.holla@arm.com>
Acked-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Some platforms add the OPPs dynamically from platform specific drivers
instead of getting them statically from DT. The cpufreq-dt driver
already ignores the return value of dev_pm_opp_of_cpumask_add_table() to
not error out for such cases, but we still end up printing error message
from that routine. That's not nice.

Convert the print message to use pr_debug() instead.
Reported-by: NMason <slash.tmp@free.fr>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

In the current code, if the user accidentally writes a bogus command to
this sysfs file, then we set the latency tolerance to an uninitialized
variable.

Fixes: 2d984ad1 (PM / QoS: Introcuce latency tolerance device PM QoS type)
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Acked-by: NPavel Machek <pavel@ucw.cz>
Cc: 3.15+ <stable@vger.kernel.org> # 3.15+
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

When CONFIG_PM_SLEEP is disabled, we don't have a pm_genpd_poweroff_noirq
function definition:

drivers/base/power/domain.c: In function 'pm_genpd_init':
drivers/base/power/domain.c:1549:37: error: 'pm_genpd_poweroff_noirq' undeclared (first use in this function); did you mean 'genpd_power_off_unused'?

This adds another NULL definition for it, just like we already have
for the other _noirq handlers.

Fixes: 10da6542 (PM / Domains: Call driver's noirq callbacks)
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Revert commit 8b55e55e (PM / Domains: Handle safely
genpd_syscore_switch() call on non-genpd device) which was misguided
(the change made by it was not necessary) and it introduced a call to
a function that may sleep into an atomic context code path.
Reported-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Commit fc5cbf0c (PM / Domains: Support for multiple states) split
out some code out of default_power_down_ok() function so the
documentation has to be moved to appropriate place.
Signed-off-by: NKrzysztof Kozlowski <krzk@kernel.org>
Acked-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

of_genpd_remove_last() iterates over list of domains and removes
matching element thus it has to use safe version of list iteration.

Fixes: 17926551 (PM / Domains: Add support for removing nested PM domains by provider)
Cc: 4.9+ <stable@vger.kernel.org> # 4.9+
Signed-off-by: NKrzysztof Kozlowski <krzk@kernel.org>
Acked-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

of_genpd_del_provider() iterates over list of domain provides and
removes matching element thus it has to use safe version of list
iteration.

Fixes: aa42240a (PM / Domains: Add generic OF-based PM domain look-up)
Cc: 3.19+ <stable@vger.kernel.org> # 3.19+
Signed-off-by: NKrzysztof Kozlowski <krzk@kernel.org>
Acked-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

pm_genpd_remove_subdomain() iterates over domain's master_links list and
removes matching element thus it has to use safe version of list
iteration.

Fixes: f721889f ("PM / Domains: Support for generic I/O PM domains (v8)")
Cc: 3.1+ <stable@vger.kernel.org> # 3.1+
Signed-off-by: NKrzysztof Kozlowski <krzk@kernel.org>
Acked-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

genpd_syscore_switch() had two problems:
 1. It silently assumed that device, it is being called for, belongs
    to generic power domain and used container_of() on its power
    domain pointer.  Such assumption might not be true always.

2. It iterated over list of generic power domains without holding
   gpd_list_lock mutex thus list could have been modified at the same
   time.

Usage of genpd_lookup_dev() solves both problems as it is safe a call
for non-generic power domains and uses mutex when iterating.
Reported-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NKrzysztof Kozlowski <krzk@kernel.org>
Acked-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Currently genpd installs its own noirq callbacks, but never calls down
to the driver's corresponding callbacks. Add these calls.
Signed-off-by: NMikko Perttunen <mperttunen@nvidia.com>
Acked-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

File size before:
   text	   data	    bss	    dec	    hex	filename
   3890	   1152	      8	   5050	   13ba	drivers/base/power/sysfs.o

File size After adding 'const':
   text	   data	    bss	    dec	    hex	filename
   4250	    800	      8	   5058	   13c2	drivers/base/power/sysfs.o
Signed-off-by: NArvind Yadav <arvind.yadav.cs@gmail.com>
Acked-by: NPavel Machek <pavel@ucw.cz>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Local instances of struct attribute_group are not modified so they can
be made const to increase code safeness.
Signed-off-by: NKrzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The 'info' string appearing in many places points to a .rodata string so
it should be passes as pointer to const.
Signed-off-by: NKrzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The pm_verb() returns a pointer to string from .rodata so it should be
marked as const.
Signed-off-by: NKrzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Mark pointer to struct generic_pm_domain const (either passed in
argument or used localy in a function), whenever it is not modifed by
the function itself.
Signed-off-by: NKrzysztof Kozlowski <krzk@kernel.org>
Acked-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The wakeirq infrastructure uses RCU to protect the list of wakeirqs. That
breaks the irq bus locking infrastructure, which is allows sleeping
functions to be called so interrupt controllers behind slow busses,
e.g. i2c, can be handled.

The wakeirq functions hold rcu_read_lock and call into irq functions, which
in case of interrupts using the irq bus locking will trigger a
might_sleep() splat.

Convert the wakeirq infrastructure to Sleepable RCU and unbreak it.

Fixes: 4990d4fe (PM / Wakeirq: Add automated device wake IRQ handling)
Reported-by: NBrian Norris <briannorris@chromium.org>
Suggested-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: NTony Lindgren <tony@atomide.com>
Tested-by: NBrian Norris <briannorris@chromium.org>
Cc: 4.2+ <stable@vger.kernel.org> # 4.2+
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

In order to support OPP switching, OPP layer needs to get pointer to the
clock for the device. Simple cases work fine without using the routines
added by this patch (i.e.  by passing connection-id as NULL), but for a
device with multiple clocks available, the OPP core needs to know the
exact name of the clk to use.

Add a new set of APIs to get that done.
Tested-by: NRajendra Nayak <rnayak@codeaurora.org>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

We create "supply-0" debugfs directory even if the device doesn't do
voltage scaling. That looks confusing, as if the regulator is found but
we never managed to get voltage levels for it.

Avoid creating such a directory unnecessarily.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

If dev_pm_opp_set_regulators() is called for a device and its regulators
are set in the OPP core, the OPP nodes for the device must contain the
"opp-microvolt" property, otherwise there is something wrong and we
better error out.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

This code was required while the OPP core was managed with help of RCUs,
but not anymore. Get rid of unnecessary alloc/memcpy operations.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The code was overly complicated here because of the limitations that we
had with RCUs (Couldn't use opp-table and OPPs outside RCU protected
section and can't call sleep-able routines from within that). But that
is long gone now.

Reorganize _generic_set_opp_regulator() in order to avoid using "struct
dev_pm_set_opp_data" and copying data into it for the case where
opp_table->set_opp is not set.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The pm_domain_data (pdd) pointer is set from genpd_alloc_dev_data() and
pdd->dev is guaranteed to be valid. There is no need to check pdd and
pdd->dev in rest of the code as pdd->dev will always be valid for a non
NULL pdd pointer.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Acked-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The ACPI SCI (System Control Interrupt) is set up as a wakeup IRQ
during suspend-to-idle transitions and, consequently, any events
signaled through it wake up the system from that state.  However,
on some systems some of the events signaled via the ACPI SCI while
suspended to idle should not cause the system to wake up.  In fact,
quite often they should just be discarded.

Arguably, systems should not resume entirely on such events, but in
order to decide which events really should cause the system to resume
and which are spurious, it is necessary to resume up to the point
when ACPI SCIs are actually handled and processed, which is after
executing dpm_resume_noirq() in the system resume path.

For this reasons, add a loop around freeze_enter() in which the
platforms can process events signaled via multiplexed IRQ lines
like the ACPI SCI and add suspend-to-idle hooks that can be
used for this purpose to struct platform_freeze_ops.

In the ACPI case, the ->wake hook is used for checking if the SCI
has triggered while suspended and deferring the interrupt-induced
system wakeup until the events signaled through it are actually
processed sufficiently to decide whether or not the system should
resume.  In turn, the ->sync hook allows all of the relevant event
queues to be flushed so as to prevent events from being missed due
to race conditions.

In addition to that, some ACPI code processing wakeup events needs
to be modified to use the "hard" version of wakeup triggers, so that
it will cause a system resume to happen on device-induced wakeup
events even if the "soft" mechanism to prevent the system from
suspending is not enabled.  However, to preserve the existing
behavior with respect to suspend-to-RAM, this only is done in
the suspend-to-idle case and only if an SCI has occurred while
suspended.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Avoid printing the device suspend/resume timing information if
CONFIG_PM_DEBUG is not set to reduce the log noise level.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Allow generic power domain providers to override the ->xlate() callback
in case the default genpd_xlate_onecell() translation callback is not
good enough.

One potential use-case for this is to allow generic power domains to be
specified by an ID rather than an index.
Signed-off-by: NThierry Reding <treding@nvidia.com>
Acked-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NThierry Reding <treding@nvidia.com>