Merge tag 'pm-5.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management updates from Rafael Wysocki:
 "These add hybrid processors support to the intel_pstate driver and
  make it work with more processor models when HWP is disabled, make the
  intel_idle driver use special C6 idle state paremeters when package
  C-states are disabled, add cooling support to the tegra30 devfreq
  driver, rework the TEO (timer events oriented) cpuidle governor,
  extend the OPP (operating performance points) framework to use the
  required-opps DT property in more cases, fix some issues and clean up
  a number of assorted pieces of code.

  Specifics:

   - Make intel_pstate support hybrid processors using abstract
     performance units in the HWP interface (Rafael Wysocki).

   - Add Icelake servers and Cometlake support in no-HWP mode to
     intel_pstate (Giovanni Gherdovich).

   - Make cpufreq_online() error path be consistent with the CPU device
     removal path in cpufreq (Rafael Wysocki).

   - Clean up 3 cpufreq drivers and the statistics code (Hailong Liu,
     Randy Dunlap, Shaokun Zhang).

   - Make intel_idle use special idle state parameters for C6 when
     package C-states are disabled (Chen Yu).

   - Rework the TEO (timer events oriented) cpuidle governor to address
     some theoretical shortcomings in it (Rafael Wysocki).

   - Drop unneeded semicolon from the TEO governor (Wan Jiabing).

   - Modify the runtime PM framework to accept unassigned suspend and
     resume callback pointers (Ulf Hansson).

   - Improve pm_runtime_get_sync() documentation (Krzysztof Kozlowski).

   - Improve device performance states support in the generic power
     domains (genpd) framework (Ulf Hansson).

   - Fix some documentation issues in genpd (Yang Yingliang).

   - Make the operating performance points (OPP) framework use the
     required-opps DT property in use cases that are not related to
     genpd (Hsin-Yi Wang).

   - Make lazy_link_required_opp_table() use list_del_init instead of
     list_del/INIT_LIST_HEAD (Yang Yingliang).

   - Simplify wake IRQs handling in the core system-wide sleep support
     code and clean up some coding style inconsistencies in it (Tian
     Tao, Zhen Lei).

   - Add cooling support to the tegra30 devfreq driver and improve its
     DT bindings (Dmitry Osipenko).

   - Fix some assorted issues in the devfreq core and drivers (Chanwoo
     Choi, Dong Aisheng, YueHaibing)"

* tag 'pm-5.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (39 commits)
  PM / devfreq: passive: Fix get_target_freq when not using required-opp
  cpufreq: Make cpufreq_online() call driver->offline() on errors
  opp: Allow required-opps to be used for non genpd use cases
  cpuidle: teo: remove unneeded semicolon in teo_select()
  dt-bindings: devfreq: tegra30-actmon: Add cooling-cells
  dt-bindings: devfreq: tegra30-actmon: Convert to schema
  PM / devfreq: userspace: Use DEVICE_ATTR_RW macro
  PM: runtime: Clarify documentation when callbacks are unassigned
  PM: runtime: Allow unassigned ->runtime_suspend|resume callbacks
  PM: runtime: Improve path in rpm_idle() when no callback
  PM: hibernate: remove leading spaces before tabs
  PM: sleep: remove trailing spaces and tabs
  PM: domains: Drop/restore performance state votes for devices at runtime PM
  PM: domains: Return early if perf state is already set for the device
  PM: domains: Split code in dev_pm_genpd_set_performance_state()
  cpuidle: teo: Use kerneldoc documentation in admin-guide
  cpuidle: teo: Rework most recent idle duration values treatment
  cpuidle: teo: Change the main idle state selection logic
  cpuidle: teo: Cosmetic modification of teo_select()
  cpuidle: teo: Cosmetic modifications of teo_update()
  ...

Author: torvalds

Documentation/admin-guide/pm/cpuidle.rst

@@ -347,81 +347,8 @@ for tickless systems.  It follows the same basic strategy as the ``menu`` `one
 <menu-gov_>`_: it always tries to find the deepest idle state suitable for the
 given conditions.  However, it applies a different approach to that problem.
 
-First, it does not use sleep length correction factors, but instead it attempts
-to correlate the observed idle duration values with the available idle states
-and use that information to pick up the idle state that is most likely to
-"match" the upcoming CPU idle interval.   Second, it does not take the tasks
-that were running on the given CPU in the past and are waiting on some I/O
-operations to complete now at all (there is no guarantee that they will run on
-the same CPU when they become runnable again) and the pattern detection code in
-it avoids taking timer wakeups into account.  It also only uses idle duration
-values less than the current time till the closest timer (with the scheduler
-tick excluded) for that purpose.
-
-Like in the ``menu`` governor `case <menu-gov_>`_, the first step is to obtain
-the *sleep length*, which is the time until the closest timer event with the
-assumption that the scheduler tick will be stopped (that also is the upper bound
-on the time until the next CPU wakeup).  That value is then used to preselect an
-idle state on the basis of three metrics maintained for each idle state provided
-by the ``CPUIdle`` driver: ``hits``, ``misses`` and ``early_hits``.
-
-The ``hits`` and ``misses`` metrics measure the likelihood that a given idle
-state will "match" the observed (post-wakeup) idle duration if it "matches" the
-sleep length.  They both are subject to decay (after a CPU wakeup) every time
-the target residency of the idle state corresponding to them is less than or
-equal to the sleep length and the target residency of the next idle state is
-greater than the sleep length (that is, when the idle state corresponding to
-them "matches" the sleep length).  The ``hits`` metric is increased if the
-former condition is satisfied and the target residency of the given idle state
-is less than or equal to the observed idle duration and the target residency of
-the next idle state is greater than the observed idle duration at the same time
-(that is, it is increased when the given idle state "matches" both the sleep
-length and the observed idle duration).  In turn, the ``misses`` metric is
-increased when the given idle state "matches" the sleep length only and the
-observed idle duration is too short for its target residency.
-
-The ``early_hits`` metric measures the likelihood that a given idle state will
-"match" the observed (post-wakeup) idle duration if it does not "match" the
-sleep length.  It is subject to decay on every CPU wakeup and it is increased
-when the idle state corresponding to it "matches" the observed (post-wakeup)
-idle duration and the target residency of the next idle state is less than or
-equal to the sleep length (i.e. the idle state "matching" the sleep length is
-deeper than the given one).
-
-The governor walks the list of idle states provided by the ``CPUIdle`` driver
-and finds the last (deepest) one with the target residency less than or equal
-to the sleep length.  Then, the ``hits`` and ``misses`` metrics of that idle
-state are compared with each other and it is preselected if the ``hits`` one is
-greater (which means that that idle state is likely to "match" the observed idle
-duration after CPU wakeup).  If the ``misses`` one is greater, the governor
-preselects the shallower idle state with the maximum ``early_hits`` metric
-(or if there are multiple shallower idle states with equal ``early_hits``
-metric which also is the maximum, the shallowest of them will be preselected).
-[If there is a wakeup latency constraint coming from the `PM QoS framework
-<cpu-pm-qos_>`_ which is hit before reaching the deepest idle state with the
-target residency within the sleep length, the deepest idle state with the exit
-latency within the constraint is preselected without consulting the ``hits``,
-``misses`` and ``early_hits`` metrics.]
-
-Next, the governor takes several idle duration values observed most recently
-into consideration and if at least a half of them are greater than or equal to
-the target residency of the preselected idle state, that idle state becomes the
-final candidate to ask for.  Otherwise, the average of the most recent idle
-duration values below the target residency of the preselected idle state is
-computed and the governor walks the idle states shallower than the preselected
-one and finds the deepest of them with the target residency within that average.
-That idle state is then taken as the final candidate to ask for.
-
-Still, at this point the governor may need to refine the idle state selection if
-it has not decided to `stop the scheduler tick <idle-cpus-and-tick_>`_.  That
-generally happens if the target residency of the idle state selected so far is
-less than the tick period and the tick has not been stopped already (in a
-previous iteration of the idle loop).  Then, like in the ``menu`` governor
-`case <menu-gov_>`_, the sleep length used in the previous computations may not
-reflect the real time until the closest timer event and if it really is greater
-than that time, a shallower state with a suitable target residency may need to
-be selected.
-
+.. kernel-doc:: drivers/cpuidle/governors/teo.c
+   :doc: teo-description
 
 .. _idle-states-representation:
 

Documentation/admin-guide/pm/intel_pstate.rst

@@ -365,6 +365,9 @@ argument is passed to the kernel in the command line.
 	inclusive) including both turbo and non-turbo P-states (see
 	`Turbo P-states Support`_).
 
+	This attribute is present only if the value exposed by it is the same
+	for all of the CPUs in the system.
+
 	The value of this attribute is not affected by the ``no_turbo``
 	setting described `below <no_turbo_attr_>`_.
 
@@ -374,6 +377,9 @@ argument is passed to the kernel in the command line.
 	Ratio of the `turbo range <turbo_>`_ size to the size of the entire
 	range of supported P-states, in percent.
 
+	This attribute is present only if the value exposed by it is the same
+	for all of the CPUs in the system.
+
 	This attribute is read-only.
 
 .. _no_turbo_attr:

Documentation/devicetree/bindings/arm/tegra/nvidia,tegra30-actmon.txt

@@ -0,0 +1,126 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/devfreq/nvidia,tegra30-actmon.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: NVIDIA Tegra30 Activity Monitor
+
+maintainers:
+  - Dmitry Osipenko <digetx@gmail.com>
+  - Jon Hunter <jonathanh@nvidia.com>
+  - Thierry Reding <thierry.reding@gmail.com>
+
+description: |
+  The activity monitor block collects statistics about the behaviour of other
+  components in the system. This information can be used to derive the rate at
+  which the external memory needs to be clocked in order to serve all requests
+  from the monitored clients.
+
+properties:
+  compatible:
+    enum:
+      - nvidia,tegra30-actmon
+      - nvidia,tegra114-actmon
+      - nvidia,tegra124-actmon
+      - nvidia,tegra210-actmon
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    maxItems: 2
+
+  clock-names:
+    items:
+      - const: actmon
+      - const: emc
+
+  resets:
+    maxItems: 1
+
+  reset-names:
+    items:
+      - const: actmon
+
+  interrupts:
+    maxItems: 1
+
+  interconnects:
+    minItems: 1
+    maxItems: 12
+
+  interconnect-names:
+    minItems: 1
+    maxItems: 12
+    description:
+      Should include name of the interconnect path for each interconnect
+      entry. Consult TRM documentation for information about available
+      memory clients, see MEMORY CONTROLLER and ACTIVITY MONITOR sections.
+
+  operating-points-v2:
+    description:
+      Should contain freqs and voltages and opp-supported-hw property, which
+      is a bitfield indicating SoC speedo ID mask.
+
+  "#cooling-cells":
+    const: 2
+
+required:
+  - compatible
+  - reg
+  - clocks
+  - clock-names
+  - resets
+  - reset-names
+  - interrupts
+  - interconnects
+  - interconnect-names
+  - operating-points-v2
+  - "#cooling-cells"
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/memory/tegra30-mc.h>
+
+    mc: memory-controller@7000f000 {
+        compatible = "nvidia,tegra30-mc";
+        reg = <0x7000f000 0x400>;
+        clocks = <&clk 32>;
+        clock-names = "mc";
+
+        interrupts = <0 77 4>;
+
+        #iommu-cells = <1>;
+        #reset-cells = <1>;
+        #interconnect-cells = <1>;
+    };
+
+    emc: external-memory-controller@7000f400 {
+        compatible = "nvidia,tegra30-emc";
+        reg = <0x7000f400 0x400>;
+        interrupts = <0 78 4>;
+        clocks = <&clk 57>;
+
+        nvidia,memory-controller = <&mc>;
+        operating-points-v2 = <&dvfs_opp_table>;
+        power-domains = <&domain>;
+
+        #interconnect-cells = <0>;
+    };
+
+    actmon@6000c800 {
+        compatible = "nvidia,tegra30-actmon";
+        reg = <0x6000c800 0x400>;
+        interrupts = <0 45 4>;
+        clocks = <&clk 119>, <&clk 57>;
+        clock-names = "actmon", "emc";
+        resets = <&rst 119>;
+        reset-names = "actmon";
+        operating-points-v2 = <&dvfs_opp_table>;
+        interconnects = <&mc TEGRA30_MC_MPCORER &emc>;
+        interconnect-names = "cpu-read";
+        #cooling-cells = <2>;
+    };

Documentation/devicetree/bindings/devfreq/nvidia,tegra30-actmon.yaml

@@ -378,7 +378,11 @@ drivers/base/power/runtime.c and include/linux/pm_runtime.h:
 
   `int pm_runtime_get_sync(struct device *dev);`
     - increment the device's usage counter, run pm_runtime_resume(dev) and
-      return its result
+      return its result;
+      note that it does not drop the device's usage counter on errors, so
+      consider using pm_runtime_resume_and_get() instead of it, especially
+      if its return value is checked by the caller, as this is likely to
+      result in cleaner code.
 
   `int pm_runtime_get_if_in_use(struct device *dev);`
     - return -EINVAL if 'power.disable_depth' is nonzero; otherwise, if the
@@ -827,6 +831,15 @@ or driver about runtime power changes.  Instead, the driver for the device's
 parent must take responsibility for telling the device's driver when the
 parent's power state changes.
 
+Note that, in some cases it may not be desirable for subsystems/drivers to call
+pm_runtime_no_callbacks() for their devices. This could be because a subset of
+the runtime PM callbacks needs to be implemented, a platform dependent PM
+domain could get attached to the device or that the device is power managed
+through a supplier device link. For these reasons and to avoid boilerplate code
+in subsystems/drivers, the PM core allows runtime PM callbacks to be
+unassigned. More precisely, if a callback pointer is NULL, the PM core will act
+as though there was a callback and it returned 0.
+
 9. Autosuspend, or automatically-delayed suspends
 =================================================