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Commit 8f5e823f authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'pm-5.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm 

Pull power management updates from Rafael Wysocki:
 "These fix the (Intel-specific) Performance and Energy Bias Hint (EPB)
  handling and expose it to user space via sysfs, fix and clean up
  several cpufreq drivers, add support for two new chips to the qoriq
  cpufreq driver, fix, simplify and clean up the cpufreq core and the
  schedutil governor, add support for "CPU" domains to the generic power
  domains (genpd) framework and provide low-level PSCI firmware support
  for that feature, fix the exynos cpuidle driver and fix a couple of
  issues in the devfreq subsystem and clean it up.

  Specifics:

   - Fix the handling of Performance and Energy Bias Hint (EPB) on Intel
     processors and expose it to user space via sysfs to avoid having to
     access it through the generic MSR I/F (Rafael Wysocki).

   - Improve the handling of global turbo changes made by the platform
     firmware in the intel_pstate driver (Rafael Wysocki).

   - Convert some slow-path static_cpu_has() callers to boot_cpu_has()
     in cpufreq (Borislav Petkov).

   - Fix the frequency calculation loop in the armada-37xx cpufreq
     driver (Gregory CLEMENT).

   - Fix possible object reference leaks in multuple cpufreq drivers
     (Wen Yang).

   - Fix kerneldoc comment in the centrino cpufreq driver (dongjian).

   - Clean up the ACPI and maple cpufreq drivers (Viresh Kumar, Mohan
     Kumar).

   - Add support for lx2160a and ls1028a to the qoriq cpufreq driver
     (Vabhav Sharma, Yuantian Tang).

   - Fix kobject memory leak in the cpufreq core (Viresh Kumar).

   - Simplify the IOwait boosting in the schedutil cpufreq governor and
     rework the TSC cpufreq notifier on x86 (Rafael Wysocki).

   - Clean up the cpufreq core and statistics code (Yue Hu, Kyle Lin).

   - Improve the cpufreq documentation, add SPDX license tags to some PM
     documentation files and unify copyright notices in them (Rafael
     Wysocki).

   - Add support for "CPU" domains to the generic power domains (genpd)
     framework and provide low-level PSCI firmware support for that
     feature (Ulf Hansson).

   - Rearrange the PSCI firmware support code and add support for
     SYSTEM_RESET2 to it (Ulf Hansson, Sudeep Holla).

   - Improve genpd support for devices in multiple power domains (Ulf
     Hansson).

   - Unify target residency for the AFTR and coupled AFTR states in the
     exynos cpuidle driver (Marek Szyprowski).

   - Introduce new helper routine in the operating performance points
     (OPP) framework (Andrew-sh.Cheng).

   - Add support for passing on-die termination (ODT) and auto power
     down parameters from the kernel to Trusted Firmware-A (TF-A) to the
     rk3399_dmc devfreq driver (Enric Balletbo i Serra).

   - Add tracing to devfreq (Lukasz Luba).

   - Make the exynos-bus devfreq driver suspend all devices on system
     shutdown (Marek Szyprowski).

   - Fix a few minor issues in the devfreq subsystem and clean it up
     somewhat (Enric Balletbo i Serra, MyungJoo Ham, Rob Herring,
     Saravana Kannan, Yangtao Li).

   - Improve system wakeup diagnostics (Stephen Boyd).

   - Rework filesystem sync messages emitted during system suspend and
     hibernation (Harry Pan)"

* tag 'pm-5.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (72 commits)
  cpufreq: Fix kobject memleak
  cpufreq: armada-37xx: fix frequency calculation for opp
  cpufreq: centrino: Fix centrino_setpolicy() kerneldoc comment
  cpufreq: qoriq: add support for lx2160a
  x86: tsc: Rework time_cpufreq_notifier()
  PM / Domains: Allow to attach a CPU via genpd_dev_pm_attach_by_id|name()
  PM / Domains: Search for the CPU device outside the genpd lock
  PM / Domains: Drop unused in-parameter to some genpd functions
  PM / Domains: Use the base device for driver_deferred_probe_check_state()
  cpufreq: qoriq: Add ls1028a chip support
  PM / Domains: Enable genpd_dev_pm_attach_by_id|name() for single PM domain
  PM / Domains: Allow OF lookup for multi PM domain case from ->attach_dev()
  PM / Domains: Don't kfree() the virtual device in the error path
  cpufreq: Move ->get callback check outside of __cpufreq_get()
  PM / Domains: remove unnecessary unlikely()
  cpufreq: Remove needless bios_limit check in show_bios_limit()
  drivers/cpufreq/acpi-cpufreq.c: This fixes the following checkpatch warning
  firmware/psci: add support for SYSTEM_RESET2
  PM / devfreq: add tracing for scheduling work
  trace: events: add devfreq trace event file
  ...
parents 59df1c2b e07095c9

Documentation/ABI/testing/sysfs-devices-system-cpu

+18 −0
Original line number Diff line number Diff line
@@ -520,3 +520,21 @@ Description: Control Symetric Multi Threading (SMT) 


			 If control status is "forceoff" or "notsupported" writes

			 are rejected.



What:		/sys/devices/system/cpu/cpu#/power/energy_perf_bias

Date:		March 2019

Contact:	linux-pm@vger.kernel.org

Description:	Intel Energy and Performance Bias Hint (EPB)



		EPB for the given CPU in a sliding scale 0 - 15, where a value

		of 0 corresponds to a hint preference for highest performance

		and a value of 15 corresponds to the maximum energy savings.



		In order to change the EPB value for the CPU, write either

		a number in the 0 - 15 sliding scale above, or one of the

		strings: "performance", "balance-performance", "normal",

		"balance-power", "power" (that represent values reflected by

		their meaning), to this attribute.



		This attribute is present for all online CPUs supporting the

		Intel EPB feature.

Documentation/admin-guide/pm/cpufreq.rst

+13 −5
Original line number Diff line number Diff line 
.. SPDX-License-Identifier: GPL-2.0

.. include:: <isonum.txt>



.. |struct cpufreq_policy| replace:: :c:type:`struct cpufreq_policy <cpufreq_policy>`

.. |intel_pstate| replace:: :doc:`intel_pstate <intel_pstate>`
@@ -5,9 +8,10 @@ 
CPU Performance Scaling

=======================



::

:Copyright: |copy| 2017 Intel Corporation



:Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>



 Copyright (c) 2017 Intel Corp., Rafael J. Wysocki <rafael.j.wysocki@intel.com>



The Concept of CPU Performance Scaling

======================================
@@ -396,8 +400,8 @@ RT or deadline scheduling classes, the governor will increase the frequency to 
the allowed maximum (that is, the ``scaling_max_freq`` policy limit).  In turn,

if it is invoked by the CFS scheduling class, the governor will use the

Per-Entity Load Tracking (PELT) metric for the root control group of the

given CPU as the CPU utilization estimate (see the `Per-entity load tracking`_

LWN.net article for a description of the PELT mechanism).  Then, the new

given CPU as the CPU utilization estimate (see the *Per-entity load tracking*

LWN.net article [1]_ for a description of the PELT mechanism).  Then, the new

CPU frequency to apply is computed in accordance with the formula



	f = 1.25 * ``f_0`` * ``util`` / ``max``
@@ -698,4 +702,8 @@ hardware feature (e.g. all Intel ones), even if the 
:c:macro:`CONFIG_X86_ACPI_CPUFREQ_CPB` configuration option is set.





.. _Per-entity load tracking: https://lwn.net/Articles/531853/
 
References

==========



.. [1] Jonathan Corbet, *Per-entity load tracking*,

       https://lwn.net/Articles/531853/

Documentation/admin-guide/pm/cpuidle.rst

+6 −2
Original line number Diff line number Diff line 
.. SPDX-License-Identifier: GPL-2.0

.. include:: <isonum.txt>



.. |struct cpuidle_state| replace:: :c:type:`struct cpuidle_state <cpuidle_state>`

.. |cpufreq| replace:: :doc:`CPU Performance Scaling <cpufreq>`
@@ -5,9 +8,10 @@ 
CPU Idle Time Management

========================



::

:Copyright: |copy| 2018 Intel Corporation



:Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>



 Copyright (c) 2018 Intel Corp., Rafael J. Wysocki <rafael.j.wysocki@intel.com>



Concepts

========

Documentation/admin-guide/pm/index.rst

+2 −0
Original line number Diff line number Diff line 
.. SPDX-License-Identifier: GPL-2.0



================

Power Management

================

Documentation/admin-guide/pm/intel_epb.rst

0 → 100644
+41 −0
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.. SPDX-License-Identifier: GPL-2.0

.. include:: <isonum.txt>



======================================

Intel Performance and Energy Bias Hint

======================================



:Copyright: |copy| 2019 Intel Corporation



:Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>





.. kernel-doc:: arch/x86/kernel/cpu/intel_epb.c

   :doc: overview



Intel Performance and Energy Bias Attribute in ``sysfs``

========================================================



The Intel Performance and Energy Bias Hint (EPB) value for a given (logical) CPU

can be checked or updated through a ``sysfs`` attribute (file) under

:file:`/sys/devices/system/cpu/cpu<N>/power/`, where the CPU number ``<N>``

is allocated at the system initialization time:



``energy_perf_bias``

	Shows the current EPB value for the CPU in a sliding scale 0 - 15, where

	a value of 0 corresponds to a hint preference for highest performance

	and a value of 15 corresponds to the maximum energy savings.



	In order to update the EPB value for the CPU, this attribute can be

	written to, either with a number in the 0 - 15 sliding scale above, or

	with one of the strings: "performance", "balance-performance", "normal",

	"balance-power", "power" that represent values reflected by their

	meaning.



	This attribute is present for all online CPUs supporting the EPB

	feature.



Note that while the EPB interface to the processor is defined at the logical CPU

level, the physical register backing it may be shared by multiple CPUs (for

example, SMT siblings or cores in one package).  For this reason, updating the

EPB value for one CPU may cause the EPB values for other CPUs to change.