Prevent rpm_get_suppliers() from returning an error code if runtime
PM is disabled for one or more of the supplier devices it wants to
runtime-resume, so as to make runtime PM work for devices with links
to suppliers that don't use runtime PM (such links may be created
during device enumeration even before it is known whether or not
runtime PM will be enabled for the devices in question, for example).

Fixes: 21d5c57b3726 (PM / runtime: Use device links)
Reported-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Lukas Wunner <lukas@wunner.de>
Tested-by: Adrian Hunter <adrian.hunter@intel.com>

The check for "active" children in __pm_runtime_set_status(), when
trying to set the parent device status to "suspended", doesn't
really make sense, because in fact it is not invalid to set the
status of a device with runtime PM disabled to "suspended" in any
case.  It is invalid to enable runtime PM for a device with its
status set to "suspended" while its child_count reference counter
is nonzero, but the check in __pm_runtime_set_status() doesn't
really cover that situation.

For this reason, drop the children check from __pm_runtime_set_status()
and add a check against child_count reference counters of "suspended"
devices to pm_runtime_enable().

Fixes: a8636c89648a (PM / Runtime: Don't allow to suspend a device with an active child)
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Johan Hovold <johan@kernel.org>

Pull power management updates from Rafael Wysocki:
 "There are no real big ticket items here this time.

  The most noticeable change is probably the relocation of the OPP
  (Operating Performance Points) framework to its own directory under
  drivers/ as it has grown big enough for that. Also Viresh is now going
  to maintain it and send pull requests for it to me, so you will see
  this change in the git history going forward (but still not right
  now).

  Another noticeable set of changes is the modifications of the PM core,
  the PCI subsystem and the ACPI PM domain to allow of more integration
  between system-wide suspend/resume and runtime PM. For now it's just a
  way to avoid resuming devices from runtime suspend unnecessarily
  during system suspend (if the driver sets a flag to indicate its
  readiness for that) and in the works is an analogous mechanism to
  allow devices to stay suspended after system resume.

  In addition to that, we have some changes related to supporting
  frequency-invariant CPU utilization metrics in the scheduler and in
  the schedutil cpufreq governor on ARM and changes to add support for
  device performance states to the generic power domains (genpd)
  framework.

  The rest is mostly fixes and cleanups of various sorts.

  Specifics:

   - Relocate the OPP (Operating Performance Points) framework to its
     own directory under drivers/ and add support for power domain
     performance states to it (Viresh Kumar).

   - Modify the PM core, the PCI bus type and the ACPI PM domain to
     support power management driver flags allowing device drivers to
     specify their capabilities and preferences regarding the handling
     of devices with enabled runtime PM during system suspend/resume and
     clean up that code somewhat (Rafael Wysocki, Ulf Hansson).

   - Add frequency-invariant accounting support to the task scheduler on
     ARM and ARM64 (Dietmar Eggemann).

   - Fix PM QoS device resume latency framework to prevent "no
     restriction" requests from overriding requests with specific
     requirements and drop the confusing PM_QOS_FLAG_REMOTE_WAKEUP
     device PM QoS flag (Rafael Wysocki).

   - Drop legacy class suspend/resume operations from the PM core and
     drop legacy bus type suspend and resume callbacks from ARM/locomo
     (Rafael Wysocki).

   - Add min/max frequency support to devfreq and clean it up somewhat
     (Chanwoo Choi).

   - Rework wakeup support in the generic power domains (genpd)
     framework and update some of its users accordingly (Geert
     Uytterhoeven).

   - Convert timers in the PM core to use timer_setup() (Kees Cook).

   - Add support for exposing the SLP_S0 (Low Power S0 Idle) residency
     counter based on the LPIT ACPI table on Intel platforms (Srinivas
     Pandruvada).

   - Add per-CPU PM QoS resume latency support to the ladder cpuidle
     governor (Ramesh Thomas).

   - Fix a deadlock between the wakeup notify handler and the notifier
     removal in the ACPI core (Ville Syrjälä).

   - Fix a cpufreq schedutil governor issue causing it to use stale
     cached frequency values sometimes (Viresh Kumar).

   - Fix an issue in the system suspend core support code causing wakeup
     events detection to fail in some cases (Rajat Jain).

   - Fix the generic power domains (genpd) framework to prevent the PM
     core from using the direct-complete optimization with it as that is
     guaranteed to fail (Ulf Hansson).

   - Fix a minor issue in the cpuidle core and clean it up a bit (Gaurav
     Jindal, Nicholas Piggin).

   - Fix and clean up the intel_idle and ARM cpuidle drivers (Jason
     Baron, Len Brown, Leo Yan).

   - Fix a couple of minor issues in the OPP framework and clean it up
     (Arvind Yadav, Fabio Estevam, Sudeep Holla, Tobias Jordan).

   - Fix and clean up some cpufreq drivers and fix a minor issue in the
     cpufreq statistics code (Arvind Yadav, Bhumika Goyal, Fabio
     Estevam, Gautham Shenoy, Gustavo Silva, Marek Szyprowski, Masahiro
     Yamada, Robert Jarzmik, Zumeng Chen).

   - Fix minor issues in the system suspend and hibernation core, in
     power management documentation and in the AVS (Adaptive Voltage
     Scaling) framework (Helge Deller, Himanshu Jha, Joe Perches, Rafael
     Wysocki).

   - Fix some issues in the cpupower utility and document that Shuah
     Khan is going to maintain it going forward (Prarit Bhargava, Shuah
     Khan)"

* tag 'pm-4.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (88 commits)
  tools/power/cpupower: add libcpupower.so.0.0.1 to .gitignore
  tools/power/cpupower: Add 64 bit library detection
  intel_idle: Graceful probe failure when MWAIT is disabled
  cpufreq: schedutil: Reset cached_raw_freq when not in sync with next_freq
  freezer: Fix typo in freezable_schedule_timeout() comment
  PM / s2idle: Clear the events_check_enabled flag
  cpufreq: stats: Handle the case when trans_table goes beyond PAGE_SIZE
  cpufreq: arm_big_little: make cpufreq_arm_bL_ops structures const
  cpufreq: arm_big_little: make function arguments and structure pointer const
  cpuidle: Avoid assignment in if () argument
  cpuidle: Clean up cpuidle_enable_device() error handling a bit
  ACPI / PM: Fix acpi_pm_notifier_lock vs flush_workqueue() deadlock
  PM / Domains: Fix genpd to deal with drivers returning 1 from ->prepare()
  cpuidle: ladder: Add per CPU PM QoS resume latency support
  PM / QoS: Fix device resume latency framework
  PM / domains: Rework governor code to be more consistent
  PM / Domains: Remove gpd_dev_ops.active_wakeup() callback
  soc: rockchip: power-domain: Use GENPD_FLAG_ACTIVE_WAKEUP
  soc: mediatek: Use GENPD_FLAG_ACTIVE_WAKEUP
  ARM: shmobile: pm-rmobile: Use GENPD_FLAG_ACTIVE_WAKEUP
  ...

* pm-core:
  ACPI / PM: Take SMART_SUSPEND driver flag into account
  PCI / PM: Take SMART_SUSPEND driver flag into account
  PCI / PM: Drop unnecessary invocations of pcibios_pm_ops callbacks
  PM / core: Add SMART_SUSPEND driver flag
  PCI / PM: Use the NEVER_SKIP driver flag
  PM / core: Add NEVER_SKIP and SMART_PREPARE driver flags
  PM / core: Convert timers to use timer_setup()
  PM / core: Fix kerneldoc comments of four functions
  PM / core: Drop legacy class suspend/resume operations

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: 85dc0b8a4019 (PM / QoS: Make it possible to expose PM QoS latency constraints)
Link: https://bugzilla.kernel.org/show_bug.cgi?id=197323
Reported-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Reinette Chatre <reinette.chatre@intel.com>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Tero Kristo <t-kristo@ti.com>
Reviewed-by: Ramesh Thomas <ramesh.thomas@intel.com>

Please do not apply this to mainline directly, instead please re-run the
coccinelle script shown below and apply its output.

For several reasons, it is desirable to use {READ,WRITE}_ONCE() in
preference to ACCESS_ONCE(), and new code is expected to use one of the
former. So far, there's been no reason to change most existing uses of
ACCESS_ONCE(), as these aren't harmful, and changing them results in
churn.

However, for some features, the read/write distinction is critical to
correct operation. To distinguish these cases, separate read/write
accessors must be used. This patch migrates (most) remaining
ACCESS_ONCE() instances to {READ,WRITE}_ONCE(), using the following
coccinelle script:

----
// Convert trivial ACCESS_ONCE() uses to equivalent READ_ONCE() and
// WRITE_ONCE()

// $ make coccicheck COCCI=/home/mark/once.cocci SPFLAGS="--include-headers" MODE=patch

virtual patch

@ depends on patch @
expression E1, E2;
@@

- ACCESS_ONCE(E1) = E2
+ WRITE_ONCE(E1, E2)

@ depends on patch @
expression E;
@@

- ACCESS_ONCE(E)
+ READ_ONCE(E)
----

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: davem@davemloft.net
Cc: linux-arch@vger.kernel.org
Cc: mpe@ellerman.id.au
Cc: shuah@kernel.org
Cc: snitzer@redhat.com
Cc: thor.thayer@linux.intel.com
Cc: tj@kernel.org
Cc: viro@zeniv.linux.org.uk
Cc: will.deacon@arm.com
Link: http://lkml.kernel.org/r/1508792849-3115-19-git-send-email-paulmck@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

In preparation for unconditionally passing the struct timer_list pointer to
all timer callbacks, switch to using the new timer_setup() and from_timer()
to pass the timer pointer explicitly. Removes test of .data field, since
that will be going away.

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Update the .c files that depend on these APIs.

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

The might_sleep_if() assertions in __pm_runtime_idle(),
__pm_runtime_suspend() and __pm_runtime_resume() may generate
false-positive warnings in some situations.  For example, that
happens if a nested pm_runtime_get_sync()/pm_runtime_put() pair
is executed with disabled interrupts within an outer
pm_runtime_get_sync()/pm_runtime_put() section for the same device.
[Generally, pm_runtime_get_sync() may sleep, so it should not be
called with disabled interrupts, but in this particular case the
previous pm_runtime_get_sync() guarantees that the device will not
be suspended, so the inner pm_runtime_get_sync() will return
immediately after incrementing the device's usage counter.]

That started to happen in the i915 driver in 4.10-rc, leading to
the following splat:

 BUG: sleeping function called from invalid context at drivers/base/power/runtime.c:1032
 in_atomic(): 1, irqs_disabled(): 0, pid: 1500, name: Xorg
 1 lock held by Xorg/1500:
  #0:  (&dev->struct_mutex){+.+.+.}, at:
  [<ffffffffa0680c13>] i915_mutex_lock_interruptible+0x43/0x140 [i915]
 CPU: 0 PID: 1500 Comm: Xorg Not tainted
 Call Trace:
  dump_stack+0x85/0xc2
  ___might_sleep+0x196/0x260
  __might_sleep+0x53/0xb0
  __pm_runtime_resume+0x7a/0x90
  intel_runtime_pm_get+0x25/0x90 [i915]
  aliasing_gtt_bind_vma+0xaa/0xf0 [i915]
  i915_vma_bind+0xaf/0x1e0 [i915]
  i915_gem_execbuffer_relocate_entry+0x513/0x6f0 [i915]
  i915_gem_execbuffer_relocate_vma.isra.34+0x188/0x250 [i915]
  ? trace_hardirqs_on+0xd/0x10
  ? i915_gem_execbuffer_reserve_vma.isra.31+0x152/0x1f0 [i915]
  ? i915_gem_execbuffer_reserve.isra.32+0x372/0x3a0 [i915]
  i915_gem_do_execbuffer.isra.38+0xa70/0x1a40 [i915]
  ? __might_fault+0x4e/0xb0
  i915_gem_execbuffer2+0xc5/0x260 [i915]
  ? __might_fault+0x4e/0xb0
  drm_ioctl+0x206/0x450 [drm]
  ? i915_gem_execbuffer+0x340/0x340 [i915]
  ? __fget+0x5/0x200
  do_vfs_ioctl+0x91/0x6f0
  ? __fget+0x111/0x200
  ? __fget+0x5/0x200
  SyS_ioctl+0x79/0x90
  entry_SYSCALL_64_fastpath+0x23/0xc6

even though the code triggering it is correct.

Unfortunately, the might_sleep_if() assertions in question are
too coarse-grained to cover such cases correctly, so make them
a bit less sensitive in order to avoid the false-positives.

Reported-and-tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Pull driver core updates from Greg KH:
 "Here's the new driver core patches for 4.10-rc1.

  Big thing here is the nice addition of "functional dependencies" to
  the driver core. The idea has been talked about for a very long time,
  great job to Rafael for stepping up and implementing it. It's been
  tested for longer than the 4.9-rc1 date, we held off on merging it
  earlier in order to feel more comfortable about it.

  Other than that, it's just a handful of small other patches, some good
  cleanups to the mess that is the firmware class code, and we have a
  test driver for the deferred probe logic.

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'driver-core-4.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (30 commits)
  firmware: Correct handling of fw_state_wait() return value
  driver core: Silence device links sphinx warning
  firmware: remove warning at documentation generation time
  drivers: base: dma-mapping: Fix typo in dmam_alloc_non_coherent comments
  driver core: test_async: fix up typo found by 0-day
  firmware: move fw_state_is_done() into UHM section
  firmware: do not use fw_lock for fw_state protection
  firmware: drop bit ops in favor of simple state machine
  firmware: refactor loading status
  firmware: fix usermode helper fallback loading
  driver core: firmware_class: convert to use class_groups
  driver core: devcoredump: convert to use class_groups
  driver core: class: add class_groups support
  kernfs: Declare two local data structures static
  driver-core: fix platform_no_drv_owner.cocci warnings
  drivers/base/memory.c: Remove unused 'first_page' variable
  driver core: add CLASS_ATTR_WO()
  drivers: base: cacheinfo: support DT overrides for cache properties
  drivers: base: cacheinfo: add pr_fmt logging
  drivers: base: cacheinfo: fix boot error message when acpi is enabled
  ...