Commit Graph

81 Commits

Author SHA1 Message Date
Linus Torvalds
42efa5e3a8 - Remove the vendor check when selecting MWAIT as the default idle state
- Respect idle=nomwait when supplied on the kernel cmdline
 
 - Two small cleanups
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Merge tag 'x86_cpu_for_v6.0_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 cpu updates from Borislav Petkov:

 - Remove the vendor check when selecting MWAIT as the default idle
   state

 - Respect idle=nomwait when supplied on the kernel cmdline

 - Two small cleanups

* tag 'x86_cpu_for_v6.0_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/cpu: Use MSR_IA32_MISC_ENABLE constants
  x86: Fix comment for X86_FEATURE_ZEN
  x86: Remove vendor checks from prefer_mwait_c1_over_halt
  x86: Handle idle=nomwait cmdline properly for x86_idle
2022-08-01 09:49:29 -07:00
Wyes Karny
8bcedb4ce0 x86: Handle idle=nomwait cmdline properly for x86_idle
When kernel is booted with idle=nomwait do not use MWAIT as the
default idle state.

If the user boots the kernel with idle=nomwait, it is a clear
direction to not use mwait as the default idle state.
However, the current code does not take this into consideration
while selecting the default idle state on x86.

Fix it by checking for the idle=nomwait boot option in
prefer_mwait_c1_over_halt().

Also update the documentation around idle=nomwait appropriately.

[ dhansen: tweak commit message ]

Signed-off-by: Wyes Karny <wyes.karny@amd.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Tested-by: Zhang Rui <rui.zhang@intel.com>
Link: https://lkml.kernel.org/r/fdc2dc2d0a1bc21c2f53d989ea2d2ee3ccbc0dbe.1654538381.git-series.wyes.karny@amd.com
2022-06-08 12:58:58 -07:00
Srinivas Pandruvada
4fe4f15523 Documentation: admin-guide: PM: Add Out of Band mode
Update documentation for using the tool to support performance level
change via OOB (Out of Band) interface.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2022-05-25 15:48:26 +02:00
Rafael J. Wysocki
3b65dd5be3 Merge branch 'pm-docs'
Merge additional power management documentation udates for 5.18-rc1:

 - Add Intel uncore frequency scaling documentation file to its
   MAINTAINERS entry (Srinivas Pandruvada).

 - Clean up the AMD P-state driver documentation (Jan Engelhardt).

* pm-docs:
  Documentation: amd-pstate: grammar and sentence structure updates
  MAINTAINERS: Add additional file to uncore frequency control
2022-03-29 18:53:28 +02:00
Jan Engelhardt
7000ef3805 Documentation: amd-pstate: grammar and sentence structure updates
Signed-off-by: Jan Engelhardt <jengelh@inai.de>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2022-03-25 18:29:57 +01:00
Rafael J. Wysocki
ec3d8b8365 Merge branch 'pm-tools'
Merge power management utilities changes for 5.18-rc1:

 - Add tracer tool for the amd-pstate driver (Jinzhou Su).

 - Fix PC6 displaying in turbostat on some systems (Artem Bityutskiy).

 - Add AMD P-State support to the cpupower utility (Huang Rui).

* pm-tools:
  Documentation: amd-pstate: add tracer tool introduction
  tools/power/x86/amd_pstate_tracer: Add tracer tool for AMD P-state
  tools/power/x86/intel_pstate_tracer: make tracer as a module
  cpufreq: amd-pstate: Add more tracepoint for AMD P-State module
  turbostat: fix PC6 displaying on some systems
  cpupower: Add "perf" option to print AMD P-State information
  cpupower: Add function to print AMD P-State performance capabilities
  cpupower: Move print_speed function into misc helper
  cpupower: Enable boost state support for AMD P-State module
  cpupower: Add AMD P-State sysfs definition and access helper
  cpupower: Introduce ACPI CPPC library
  cpupower: Add the function to get the sysfs value from specific table
  cpupower: Initial AMD P-State capability
  cpupower: Add the function to check AMD P-State enabled
  cpupower: Add AMD P-State capability flag
  tools/power/cpupower/{ToDo => TODO}: Rename the todo file
  tools: cpupower: fix typo in cpupower-idle-set(1) manpage
2022-03-18 18:46:15 +01:00
Jinzhou Su
b020771a66 Documentation: amd-pstate: add tracer tool introduction
Add amd pstate tracer tool introduction

Signed-off-by: Jinzhou Su <Jinzhou.Su@amd.com>
Reviewed-by: Huang Rui <ray.huang@amd.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2022-03-09 19:53:01 +01:00
Srinivas Pandruvada
a644161ba1 Documentation: admin-guide: pm: Document uncore frequency scaling
Added documentation to configure uncore frequency limits in Intel
Xeon processors.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
[ rjw: Clean up the document wording ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2022-03-01 16:46:53 +01:00
Huang Rui
c22760885f Documentation: amd-pstate: Add AMD P-State driver introduction
Introduce the AMD P-State driver design and implementation.

Signed-off-by: Huang Rui <ray.huang@amd.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2021-12-30 18:51:40 +01:00
Linus Torvalds
3563f55ce6 Power management updates for 5.14-rc1
- 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).
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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()
  ...
2021-06-29 13:36:06 -07:00
Rafael J. Wysocki
ed562d280c Merge branches 'pm-cpufreq' and 'pm-cpuidle'
* pm-cpufreq:
  cpufreq: Make cpufreq_online() call driver->offline() on errors
  cpufreq: loongson2: Remove unused linux/sched.h headers
  cpufreq: sh: Remove unused linux/sched.h headers
  cpufreq: stats: Clean up local variable in cpufreq_stats_create_table()
  cpufreq: intel_pstate: hybrid: Fix build with CONFIG_ACPI unset
  cpufreq: sc520_freq: add 'fallthrough' to one case
  cpufreq: intel_pstate: Add Cometlake support in no-HWP mode
  cpufreq: intel_pstate: Add Icelake servers support in no-HWP mode
  cpufreq: intel_pstate: hybrid: CPU-specific scaling factor
  cpufreq: intel_pstate: hybrid: Avoid exposing two global attributes

* pm-cpuidle:
  cpuidle: teo: remove unneeded semicolon in teo_select()
  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()
  intel_idle: Adjust the SKX C6 parameters if PC6 is disabled
2021-06-29 15:53:07 +02:00
Mauro Carvalho Chehab
17420f3138 docs: admin-guide: pm: avoid using ReST :doc:foo markup
The :doc:`foo` tag is auto-generated via automarkup.py.
So, use the filename at the sources, instead of :doc:`foo`.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/04616d9fc0b4a0d33486fa0018631a2db2eba860.1623824363.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-06-17 13:24:36 -06:00
Rafael J. Wysocki
154ae8bb3c cpuidle: teo: Use kerneldoc documentation in admin-guide
There are two descriptions of the TEO (Timer Events Oriented) cpuidle
governor in the kernel source tree, one in the C file containing its
code and one in cpuidle.rst which is part of admin-guide.

Instead of trying to keep them both in sync and in order to reduce
text duplication, include the governor description from the C file
directly into cpuidle.rst.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2021-06-11 18:36:45 +02:00
Rafael J. Wysocki
c3d175e485 cpufreq: intel_pstate: hybrid: Avoid exposing two global attributes
The turbo_pct and num_pstates sysfs attributes represent CPU
properties that may be different for differenty types of CPUs in
a hybrid processor, so avoid exposing them in that case.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2021-05-21 18:44:55 +02:00
Andrew Klychkov
751d5b2741 Documentation: fix multiple typos found in the admin-guide subdirectory
Fix thirty five typos in dm-integrity.rst, dm-raid.rst, dm-zoned.rst,
verity.rst, writecache.rst, tsx_async_abort.rst, md.rst, bttv.rst,
dvb_references.rst, frontend-cardlist.rst, gspca-cardlist.rst, ipu3.rst,
remote-controller.rst, mm/index.rst, numaperf.rst, userfaultfd.rst,
module-signing.rst, imx-ddr.rst, intel-speed-select.rst,
intel_pstate.rst, ramoops.rst, abi.rst, kernel.rst, vm.rst

Signed-off-by: Andrew Klychkov <andrew.a.klychkov@gmail.com>
Link: https://lore.kernel.org/r/20201204072848.GA49895@spblnx124.lan
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-12-08 10:27:56 -07:00
Julia Lawall
23d18dcfc5 Documentation: PM: cpuidle: correct path name
cpu/ is needed before cpu<N>/

Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-11-02 18:02:20 +01:00
Julia Lawall
6841ca15fe Documentation: PM: cpuidle: correct typo
cerainly -> certainly

Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-11-02 18:00:08 +01:00
Mauro Carvalho Chehab
abc59fd4a5 docs: remove some replace macros like |struct foo|
There are three files with replace macros for structs,
mapping them into Sphinx 2.x C domain references.

Well, this is broken on Sphinx 3.x. Also, for Sphinx 2.x,
the automarkup macro should be able to take care of them.

So, let's just drop those.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-10-15 07:49:40 +02:00
Rafael J. Wysocki
0b9688ee95 Merge back cpuidle material for 5.10.
* pm-cpuidle:
  cpuidle: record state entry rejection statistics
  cpuidle: psci: Allow PM domain to be initialized even if no OSI mode
  firmware: psci: Extend psci_set_osi_mode() to allow reset to PC mode
  ACPI: processor: Print more information when acpi_processor_evaluate_cst() fails
  cpuidle: tegra: Correctly handle result of arm_cpuidle_simple_enter()
2020-10-05 13:11:17 +02:00
Yoann Congal
eac53b3e30 Documentation: PM: Fix a reStructuredText syntax error
Fix a reStructuredText syntax error in the cpuidle PM admin-guide
documentation: the ``...'' quotation marks are parsed as partial ''...''
reStructuredText markup and break the output formatting.

This change them to "...".

Signed-off-by: Yoann Congal <yoann.congal@smile.fr>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-09-30 17:40:37 +02:00
Lina Iyer
f49735f497 cpuidle: record state entry rejection statistics
CPUs may fail to enter the chosen idle state if there was a
pending interrupt, causing the cpuidle driver to return an error
value.

Record that and export it via sysfs along with the other idle state
statistics.

This could prove useful in understanding behavior of the governor
and the system during usecases that involve multiple CPUs.

Signed-off-by: Lina Iyer <ilina@codeaurora.org>
[ rjw: Changelog and documentation edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-09-23 14:10:31 +02:00
Rafael J. Wysocki
b388eb58ce cpufreq: intel_pstate: Tweak the EPP sysfs interface
Modify the EPP sysfs interface to reject attempts to change the EPP
to values different from 0 ("performance") in the active mode with
the "performance" policy (ie. scaling_governor set to "performance"),
to avoid situations in which the kernel appears to discard data
passed to it via the EPP sysfs attribute.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
2020-09-01 21:14:06 +02:00
Randy Dunlap
1c50282199 Documentation: fix pm/intel_pstate build warning and wording
Fix documentation build warning and sentence wording:

Documentation/admin-guide/pm/intel_pstate.rst:568: WARNING: Unexpected indentation.

Fixes: f473bf398b ("cpufreq: intel_pstate: Allow raw energy performance preference value")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-08-24 12:48:37 +02:00
Rafael J. Wysocki
f3db6de55e Merge branch 'pm-cpufreq'
* pm-cpufreq:
  cpufreq: intel_pstate: Implement passive mode with HWP enabled
2020-08-14 19:39:35 +02:00
Rafael J. Wysocki
f6ebbcf08f cpufreq: intel_pstate: Implement passive mode with HWP enabled
Allow intel_pstate to work in the passive mode with HWP enabled and
make it set the HWP minimum performance limit (HWP floor) to the
P-state value given by the target frequency supplied by the cpufreq
governor, so as to prevent the HWP algorithm and the CPU scheduler
from working against each other, at least when the schedutil governor
is in use, and update the intel_pstate documentation accordingly.

Among other things, this allows utilization clamps to be taken
into account, at least to a certain extent, when intel_pstate is
in use and makes it more likely that sufficient capacity for
deadline tasks will be provided.

After this change, the resulting behavior of an HWP system with
intel_pstate in the passive mode should be close to the behavior
of the analogous non-HWP system with intel_pstate in the passive
mode, except that the HWP algorithm is generally allowed to make the
CPU run at a frequency above the floor P-state set by intel_pstate in
the entire available range of P-states, while without HWP a CPU can
run in a P-state above the requested one if the latter falls into the
range of turbo P-states (referred to as the turbo range) or if the
P-states of all CPUs in one package are coordinated with each other
at the hardware level.

[Note that in principle the HWP floor may not be taken into account
 by the processor if it falls into the turbo range, in which case the
 processor has a license to choose any P-state, either below or above
 the HWP floor, just like a non-HWP processor in the case when the
 target P-state falls into the turbo range.]

With this change applied, intel_pstate in the passive mode assumes
complete control over the HWP request MSR and concurrent changes of
that MSR (eg. via the direct MSR access interface) are overridden by
it.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Reviewed-by: Francisco Jerez <currojerez@riseup.net>
2020-08-11 17:29:45 +02:00
Linus Torvalds
2324d50d05 It's been a busy cycle for documentation - hopefully the busiest for a
while to come.  Changes include:
 
  - Some new Chinese translations
 
  - Progress on the battle against double words words and non-HTTPS URLs
 
  - Some block-mq documentation
 
  - More RST conversions from Mauro.  At this point, that task is
    essentially complete, so we shouldn't see this kind of churn again for a
    while.  Unless we decide to switch to asciidoc or something...:)
 
  - Lots of typo fixes, warning fixes, and more.
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Merge tag 'docs-5.9' of git://git.lwn.net/linux

Pull documentation updates from Jonathan Corbet:
 "It's been a busy cycle for documentation - hopefully the busiest for a
  while to come. Changes include:

   - Some new Chinese translations

   - Progress on the battle against double words words and non-HTTPS
     URLs

   - Some block-mq documentation

   - More RST conversions from Mauro. At this point, that task is
     essentially complete, so we shouldn't see this kind of churn again
     for a while. Unless we decide to switch to asciidoc or
     something...:)

   - Lots of typo fixes, warning fixes, and more"

* tag 'docs-5.9' of git://git.lwn.net/linux: (195 commits)
  scripts/kernel-doc: optionally treat warnings as errors
  docs: ia64: correct typo
  mailmap: add entry for <alobakin@marvell.com>
  doc/zh_CN: add cpu-load Chinese version
  Documentation/admin-guide: tainted-kernels: fix spelling mistake
  MAINTAINERS: adjust kprobes.rst entry to new location
  devices.txt: document rfkill allocation
  PCI: correct flag name
  docs: filesystems: vfs: correct flag name
  docs: filesystems: vfs: correct sync_mode flag names
  docs: path-lookup: markup fixes for emphasis
  docs: path-lookup: more markup fixes
  docs: path-lookup: fix HTML entity mojibake
  CREDITS: Replace HTTP links with HTTPS ones
  docs: process: Add an example for creating a fixes tag
  doc/zh_CN: add Chinese translation prefer section
  doc/zh_CN: add clearing-warn-once Chinese version
  doc/zh_CN: add admin-guide index
  doc:it_IT: process: coding-style.rst: Correct __maybe_unused compiler label
  futex: MAINTAINERS: Re-add selftests directory
  ...
2020-08-04 22:47:54 -07:00
Randy Dunlap
b45225b41a Documentation/admin-guide: intel-speed-select: drop doubled words
Drop the doubled words "that" and "and".

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-doc@vger.kernel.org
Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Cc: platform-driver-x86@vger.kernel.org
Link: https://lore.kernel.org/r/20200704032020.21923-11-rdunlap@infradead.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-07-05 14:01:49 -06:00
Randy Dunlap
4d7e204f7d Documentation/admin-guide: intel_pstate: drop doubled word
Drop the doubled word "to".

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-doc@vger.kernel.org
Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Cc: Len Brown <lenb@kernel.org>
Cc: linux-pm@vger.kernel.org
Link: https://lore.kernel.org/r/20200704032020.21923-10-rdunlap@infradead.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-07-05 14:01:49 -06:00
Quentin Perret
8412b4563e cpufreq: Specify default governor on command line
Currently, the only way to specify the default CPUfreq governor is
via Kconfig options, which suits users who can build the kernel
themselves perfectly.

However, for those who use a distro-like kernel (such as Android,
with the Generic Kernel Image project), the only way to use a
non-default governor is to boot to userspace, and to then switch
using the sysfs interface. Being able to specify the default governor
on the command line, like is the case for cpuidle, would allow those
users to specify their governor of choice earlier on, and to simplify
the userspace boot procedure slighlty.

To support this use-case, add a kernel command line parameter
allowing the default governor for CPUfreq to be specified, which
takes precedence over the built-in default.

This implementation has one notable limitation: the default governor
must be registered before the driver. This is solved for builtin
governors and drivers using appropriate *_initcall() functions. And
in the modular case, this must be reflected as a constraint on the
module loading order.

Signed-off-by: Quentin Perret <qperret@google.com>
[ Viresh: Converted 'default_governor' to a string and parsing it only
	  at initcall level, and several updates to
	  cpufreq_init_policy(). ]
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
[ rjw: Changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-07-02 13:03:30 +02:00
Srinivas Pandruvada
f473bf398b cpufreq: intel_pstate: Allow raw energy performance preference value
Currently using attribute "energy_performance_preference", user space can
write one of the four per-defined preference string. These preference
strings gets mapped to a hard-coded Energy-Performance Preference (EPP) or
Energy-Performance Bias (EPB) knob.

These four values are supposed to cover broad spectrum of use cases, but
are not uniformly distributed in the range. There are number of cases,
where this is not enough. For example:

Suppose user wants more performance when connected to AC. Instead of using
default "balance performance", the "performance" setting can be used. This
changes EPP value from 0x80 to 0x00. But setting EPP to 0, results in
electrical and thermal issues on some platforms. This results in
aggressive throttling, which causes a drop in performance. But some value
between 0x80 and 0x00 results in better performance. But that value can't
be fixed as the power curve is not linear. In some cases just changing EPP
from 0x80 to 0x75 is enough to get significant performance gain.

Similarly on battery the default "balance_performance" mode can be
aggressive in power consumption. But picking up the next choice
"balance power" results in too much loss of performance, which results in
bad user experience in use cases like "Google Hangout". It was observed
that some value between these two EPP is optimal.

This change allows fine grain EPP tuning for platform like Chromebook or
for users who wants to fine tune power and performance.
Here based on the product and use cases, different EPP values can be set.
This change is similar to the change done for:
/sys/devices/system/cpu/cpu*/power/energy_perf_bias
where user has choice to write a predefined string or raw value.

The change itself is trivial. When user preference doesn't match
predefined string preferences and value is an unsigned integer and in
range, use that value for EPP. When the EPP feature is not present
writing raw value is not supported.

Suggested-by: Len Brown <lenb@kernel.org>
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-07-02 13:02:46 +02:00
Srinivas Pandruvada
ed7bde7a6d cpufreq: intel_pstate: Allow enable/disable energy efficiency
By default intel_pstate the driver disables energy efficiency by setting
MSR_IA32_POWER_CTL bit 19 for Kaby Lake desktop CPU model in HWP mode.
This CPU model is also shared by Coffee Lake desktop CPUs. This allows
these systems to reach maximum possible frequency. But this adds power
penalty, which some customers don't want. They want some way to enable/
disable dynamically.

So, add an additional attribute "energy_efficiency" under
/sys/devices/system/cpu/intel_pstate/ for these CPU models. This allows
to read and write bit 19 ("Disable Energy Efficiency Optimization") in
the MSR IA32_POWER_CTL.

This attribute is present in both HWP and non-HWP mode as this has an
effect in both modes. Refer to Intel Software Developer's manual for
details.

The scope of this bit is package wide. Also these systems are single
package systems. So read/write MSR on the current CPU is enough.

The energy efficiency (EE) bit setting needs to be preserved during
suspend/resume and CPU offline/online operation. To do this:
- Restoring the EE setting from the cpufreq resume() callback, if there
is change from the system default.
- By default, don't disable EE from cpufreq init() callback for matching
CPU models. Since the scope is package wide and is a single package
system, move the disable EE calls from init() callback to
intel_pstate_init() function, which is called only once.

Suggested-by: Len Brown <lenb@kernel.org>
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-07-02 13:02:46 +02:00
Rafael J. Wysocki
a34024d98e Merge branches 'pm-devfreq', 'powercap', 'pm-docs' and 'pm-tools'
* pm-devfreq:
  PM / devfreq: Use lockdep asserts instead of manual checks for locked mutex
  PM / devfreq: imx-bus: Fix inconsistent IS_ERR and PTR_ERR
  PM / devfreq: Replace strncpy with strscpy
  PM / devfreq: imx: Register interconnect device
  PM / devfreq: Add generic imx bus scaling driver
  PM / devfreq: tegra30: Delete an error message in tegra_devfreq_probe()
  PM / devfreq: tegra30: Make CPUFreq notifier to take into account boosting

* powercap:
  powercap: RAPL: remove unused local MSR define
  powercap/intel_rapl: add support for ElkhartLake

* pm-docs:
  Documentation: admin-guide: pm: Document intel-speed-select

* pm-tools:
  cpupower: Remove unneeded semicolon
2020-06-01 15:20:45 +02:00
Rafael J. Wysocki
ac7ccfc75f Merge branch 'pm-cpufreq'
* pm-cpufreq:
  cpufreq: Fix up cpufreq_boost_set_sw()
  cpufreq: fix minor typo in struct cpufreq_driver doc comment
  cpufreq: qoriq: Add platform dependencies
  clk: qoriq: add cpufreq platform device
  cpufreq: qoriq: convert to a platform driver
  cpufreq: qcom: fix wrong compatible binding
  cpufreq: imx-cpufreq-dt: support i.MX7ULP
  cpufreq: dt: Add support for r8a7742
  cpufreq: Add i.MX7ULP to cpufreq-dt-platdev blacklist
  cpufreq: omap: Build driver by default for ARCH_OMAP2PLUS
  cpufreq: intel_pstate: Use passive mode by default without HWP
2020-06-01 15:19:39 +02:00
Srinivas Pandruvada
213081dadd Documentation: admin-guide: pm: Document intel-speed-select
Added documentation to configure servers to use Intel(R) Speed
Select Technology using intel-speed-select tool.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Acked-by: Andriy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-05-19 19:59:10 +02:00
Hanjun Guo
7395683a24 Documentation: cpuidle: update the document
Update the document after the remove of cpuidle_sysfs_switch.

Signed-off-by: Hanjun Guo <guohanjun@huawei.com>
Reviewed-by: Doug Smythies <dsmythies@telus.net>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-05-19 17:41:17 +02:00
Rafael J. Wysocki
33aa46f252 cpufreq: intel_pstate: Use passive mode by default without HWP
After recent changes allowing scale-invariant utilization to be
used on x86, the schedutil governor on top of intel_pstate in the
passive mode should be on par with (or better than) the active mode
"powersave" algorithm of intel_pstate on systems in which
hardware-managed P-states (HWP) are not used, so it should not be
necessary to use the internal scaling algorithm in those cases.

Accordingly, modify intel_pstate to start in the passive mode by
default if the processor at hand does not support HWP of if the driver
is requested to avoid using HWP through the kernel command line.

Among other things, that will allow utilization clamps and the
support for RT/DL tasks in the schedutil governor to be utilized on
systems in which intel_pstate is used.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-04-17 17:04:38 +02:00
Rafael J. Wysocki
4506c531f1 Documentation: PM: sleep: Document system-wide suspend code flows
Add a document describing high-level system-wide suspend code flows
in Linux.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-04-03 11:41:01 +02:00
Rafael J. Wysocki
2409000a0c Merge branches 'pm-devfreq', 'powercap' and 'pm-docs'
* pm-devfreq:
  PM / devfreq: Get rid of some doc warnings
  PM / devfreq: Fix handling dev_pm_qos_remove_request result
  PM / devfreq: Fix a typo in a comment
  PM / devfreq: Change to DEVFREQ_GOV_UPDATE_INTERVAL event name
  PM / devfreq: Remove unneeded extern keyword
  PM / devfreq: Use constant name of userspace governor

* powercap:
  powercap: idle_inject: Replace zero-length array with flexible-array member

* pm-docs:
  docs: cpu-freq: convert cpufreq-stats.txt to ReST
  docs: cpu-freq: convert cpu-drivers.txt to ReST
  docs: cpu-freq: convert core.txt to ReST
  docs: cpu-freq: convert index.txt to ReST
  docs: cpufreq: fix a broken reference
  Documentation: cpufreq: Move legacy driver documentation
2020-03-30 14:48:31 +02:00
Rafael J. Wysocki
0411f0d10e Merge branch 'pm-cpufreq'
* pm-cpufreq:
  cpufreq: intel_pstate: Simplify intel_pstate_cpu_init()
  cpufreq: qcom: Add support for krait based socs
  cpufreq: imx6q-cpufreq: Improve the logic of -EPROBE_DEFER handling
  cpufreq: Use scnprintf() for avoiding potential buffer overflow
  Documentation: intel_pstate: update links for references
  cpufreq: intel_pstate: Consolidate policy verification
  cpufreq: dt: Allow platform specific intermediate callbacks
  cpufreq: imx-cpufreq-dt: Correct i.MX8MP's market segment fuse location
  cpufreq: imx6q: read OCOTP through nvmem for imx6q
  cpufreq: imx6q: fix error handling
  cpufreq: imx-cpufreq-dt: Add "cpu-supply" property check
  cpufreq: ti-cpufreq: Add support for OPP_PLUS
  cpufreq: imx6q: Fixes unwanted cpu overclocking on i.MX6ULL
2020-03-30 14:46:27 +02:00
Alex Hung
c1f59a3782 Documentation: intel_pstate: update links for references
URLs for presentation and Intel Software Developer’s Manual are updated
as they were using "http" which are gradually replaced by "https".

Signed-off-by: Alex Hung <alex.hung@canonical.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-03-14 11:46:02 +01:00
Rafael J. Wysocki
03b2249650 Documentation: cpufreq: Move legacy driver documentation
There are three legacy driver documents in Documentation/cpu-freq/
that were added years ago and converting them each to the .rst
format is rather pointless, even though there is some value in
preserving them.  However, if they are preserved, they need to go
into the admin-guide part of cpufreq documentation where they belong
(at least to a certain extent).

To preserve them with minimum amount of changes and put them into the
right place, and make it possible to process them into HTML (and other
formats) along with the rest of the documentation, move them each
as a "literal text" block into a separate section of a single .rst
"wrapper" file under Documentation/admin-guide/pm/.

While at it, repair the PCC specification URL in one of them.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-03-02 11:31:06 +01:00
Rafael J. Wysocki
b8e6e27c62 Documentation: PM: QoS: Update to reflect previous code changes
Update the PM QoS documentation to reflect the previous code changes
regarding the removal of PM QoS classes and the CPU latency QoS API
rework.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org>
Tested-by: Amit Kucheria <amit.kucheria@linaro.org>
2020-02-14 10:37:26 +01:00
Rafael J. Wysocki
332008256f Merge branches 'pm-avs' and 'pm-cpuidle'
* pm-avs:
  power: avs: qcom-cpr: Avoid clang -Wsometimes-uninitialized in cpr_scale
  power: avs: qcom-cpr: add unspecified HAS_IOMEM dependency
  PM / AVS: rockchip-io: fix the supply naming for the emmc supply on px30
  power: avs: qcom-cpr: add a printout after the driver has been initialized

* pm-cpuidle:
  cpuidle: Documentation: Clean up PM QoS description
  intel_idle: Introduce 'states_off' module parameter
  intel_idle: Introduce 'use_acpi' module parameter
2020-02-07 11:01:40 +01:00
Rafael J. Wysocki
f06572ef47 cpuidle: Documentation: Clean up PM QoS description
Clean up the language in one paragraph in the PM QoS description in
Documentation/admin-guide/pm/cpuidle.rst.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-02-05 02:08:31 +01:00
Rafael J. Wysocki
c21502efda Documentation: admin-guide: PM: Update sleep states documentation
There is some information in Documentation/power/interface.rst that
is still missing from Documentation/admin-guide/pm/sleep-states.rst
and really should be present in there, so update the latter by
adding that information to it and delete the former (as it becomes
redundant after that and it is somewhat outdated).

While at it, clean up some assorted pieces of sleep-states.rst a bit.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-02-03 11:58:26 +01:00
Rafael J. Wysocki
4dcb78ee57 intel_idle: Introduce 'states_off' module parameter
In certain system configurations it may not be desirable to use some
C-states assumed to be available by intel_idle and the driver needs
to be prevented from using them even before the cpuidle sysfs
interface becomes accessible to user space.  Currently, the only way
to achieve that is by setting the 'max_cstate' module parameter to a
value lower than the index of the shallowest of the C-states in
question, but that may be overly intrusive, because it effectively
makes all of the idle states deeper than the 'max_cstate' one go
away (and the C-state to avoid may be in the middle of the range
normally regarded as available).

To allow that limitation to be overcome, introduce a new module
parameter called 'states_off' to represent a list of idle states to
be disabled by default in the form of a bitmask and update the
documentation to cover it.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-02-03 11:57:18 +01:00
Rafael J. Wysocki
3a5be9b8f4 intel_idle: Introduce 'use_acpi' module parameter
For diagnostics, it is generally useful to be able to make intel_idle
take the system's ACPI tables into consideration even if that is not
required for the processor model in there, so introduce a new module
parameter, 'use_acpi', to make that happen and update the documentation
to cover it.

While at it, fix the 'no_acpi' module parameter name in the
documentation.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-02-03 11:57:08 +01:00
Rafael J. Wysocki
a329918221 Documentation: admin-guide: PM: Add intel_idle document
Add an admin-guide document for the intel_idle driver to describe
how it works: how it enumerates idle states, what happens during the
initialization of it, how it can be controlled via the kernel command
line and so on.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
2020-01-15 10:54:58 +01:00
Rafael J. Wysocki
75a8026741 cpuidle: Allow idle states to be disabled by default
In certain situations it may be useful to prevent some idle states
from being used by default while allowing user space to enable them
later on.

For this purpose, introduce a new state flag, CPUIDLE_FLAG_OFF, to
mark idle states that should be disabled by default, make the core
set CPUIDLE_STATE_DISABLED_BY_USER for those states at the
initialization time and add a new state attribute in sysfs,
"default_status", to inform user space of the initial status of
the given idle state ("disabled" if CPUIDLE_FLAG_OFF is set for it,
"enabled" otherwise).

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-12-27 11:02:08 +01:00
Rafael J. Wysocki
7afc53951a Merge branches 'pm-docs' and 'pm-misc'
* pm-docs:
  Documentation: PM: Unify copyright notices
  Documentation: PM: Add SPDX license tags to multiple files
  cpufreq: intel_pstate: Documentation: Add references sections

* pm-misc:
  firmware/psci: add support for SYSTEM_RESET2
  drivers: firmware: psci: Announce support for OS initiated suspend mode
  drivers: firmware: psci: Simplify error path of psci_dt_init()
  drivers: firmware: psci: Split psci_dt_cpu_init_idle()
  MAINTAINERS: Update files for PSCI
  drivers: firmware: psci: Move psci to separate directory
2019-05-06 10:55:19 +02:00