lkml.org 
[lkml]   [2019]   [Apr]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v2 10/79] docs: cpu-freq: convert docs to ReST and rename to *.rst
Date
The conversion is actually:
- add blank lines and identation in order to identify paragraphs;
- fix tables markups;
- add some lists markups;
- mark literal blocks;
- adjust title markups.

At its new index.rst, let's add a :orphan: while this is not linked to
the main index.rst file, in order to avoid build warnings.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
---
.../{amd-powernow.txt => amd-powernow.rst} | 11 +-
Documentation/cpu-freq/{core.txt => core.rst} | 66 +++---
.../{cpu-drivers.txt => cpu-drivers.rst} | 217 +++++++++---------
...pufreq-nforce2.txt => cpufreq-nforce2.rst} | 12 +-
Documentation/cpu-freq/cpufreq-stats.rst | 128 +++++++++++
Documentation/cpu-freq/cpufreq-stats.txt | 127 ----------
Documentation/cpu-freq/index.rst | 52 +++++
Documentation/cpu-freq/index.txt | 56 -----
.../{pcc-cpufreq.txt => pcc-cpufreq.rst} | 102 ++++----
drivers/cpufreq/Kconfig.x86 | 2 +-
10 files changed, 391 insertions(+), 382 deletions(-)
rename Documentation/cpu-freq/{amd-powernow.txt => amd-powernow.rst} (91%)
rename Documentation/cpu-freq/{core.txt => core.rst} (67%)
rename Documentation/cpu-freq/{cpu-drivers.txt => cpu-drivers.rst} (57%)
rename Documentation/cpu-freq/{cpufreq-nforce2.txt => cpufreq-nforce2.rst} (65%)
create mode 100644 Documentation/cpu-freq/cpufreq-stats.rst
delete mode 100644 Documentation/cpu-freq/cpufreq-stats.txt
create mode 100644 Documentation/cpu-freq/index.rst
delete mode 100644 Documentation/cpu-freq/index.txt
rename Documentation/cpu-freq/{pcc-cpufreq.txt => pcc-cpufreq.rst} (80%)

diff --git a/Documentation/cpu-freq/amd-powernow.txt b/Documentation/cpu-freq/amd-powernow.rst
similarity index 91%
rename from Documentation/cpu-freq/amd-powernow.txt
rename to Documentation/cpu-freq/amd-powernow.rst
index 254da155fa47..50b2c45c3a2c 100644
--- a/Documentation/cpu-freq/amd-powernow.txt
+++ b/Documentation/cpu-freq/amd-powernow.rst
@@ -1,3 +1,7 @@
+=============================
+AMD powernow driver specifics
+=============================
+

PowerNow! and Cool'n'Quiet are AMD names for frequency
management capabilities in AMD processors. As the hardware
@@ -23,16 +27,19 @@ not supply these tables.
7th Generation: powernow-k7: Athlon, Duron, Geode.

8th Generation: powernow-k8: Athlon, Athlon 64, Opteron, Sempron.
+
Documentation on this functionality in 8th generation processors
is available in the "BIOS and Kernel Developer's Guide", publication
-26094, in chapter 9, available for download from www.amd.com.
+26094, in chapter 9, available for download from www.amd.com.

BIOS supplied data, for powernow-k7 and for powernow-k8, may be
from either the PSB table or from ACPI objects. The ACPI support
is only available if the kernel config sets CONFIG_ACPI_PROCESSOR.
+
The powernow-k8 driver will attempt to use ACPI if so configured,
and fall back to PST if that fails.
+
The powernow-k7 driver will try to use the PSB support first, and
fall back to ACPI if the PSB support fails. A module parameter,
-acpi_force, is provided to force ACPI support to be used instead
+acpi_force, is provided to force ACPI support to be used instead
of PSB support.
diff --git a/Documentation/cpu-freq/core.txt b/Documentation/cpu-freq/core.rst
similarity index 67%
rename from Documentation/cpu-freq/core.txt
rename to Documentation/cpu-freq/core.rst
index 073f128af5a7..c719e3cb700c 100644
--- a/Documentation/cpu-freq/core.txt
+++ b/Documentation/cpu-freq/core.rst
@@ -1,31 +1,22 @@
- CPU frequency and voltage scaling code in the Linux(TM) kernel
+================================================================
+General description of the CPUFreq core and of CPUFreq notifiers
+================================================================

+Authors:
+ - Dominik Brodowski <linux@brodo.de>
+ - David Kimdon <dwhedon@debian.org>
+ - Rafael J. Wysocki <rafael.j.wysocki@intel.com>
+ - Viresh Kumar <viresh.kumar@linaro.org>

- L i n u x C P U F r e q

- C P U F r e q C o r e
+.. Contents:

-
- Dominik Brodowski <linux@brodo.de>
- David Kimdon <dwhedon@debian.org>
- Rafael J. Wysocki <rafael.j.wysocki@intel.com>
- Viresh Kumar <viresh.kumar@linaro.org>
-
-
-
- Clock scaling allows you to change the clock speed of the CPUs on the
- fly. This is a nice method to save battery power, because the lower
- the clock speed, the less power the CPU consumes.
-
-
-Contents:
----------
-1. CPUFreq core and interfaces
-2. CPUFreq notifiers
-3. CPUFreq Table Generation with Operating Performance Point (OPP)
+ 1. CPUFreq core and interfaces
+ 2. CPUFreq notifiers
+ 3. CPUFreq Table Generation with Operating Performance Point (OPP)

1. General Information
-=======================
+======================

The CPUFreq core code is located in drivers/cpufreq/cpufreq.c. This
cpufreq code offers a standardized interface for the CPUFreq
@@ -60,18 +51,18 @@ transition notifiers.
These are notified when a new policy is intended to be set. Each
CPUFreq policy notifier is called twice for a policy transition:

-1.) During CPUFREQ_ADJUST all CPUFreq notifiers may change the limit if
- they see a need for this - may it be thermal considerations or
- hardware limitations.
+1) During CPUFREQ_ADJUST all CPUFreq notifiers may change the limit if
+ they see a need for this - may it be thermal considerations or
+ hardware limitations.

-2.) And during CPUFREQ_NOTIFY all notifiers are informed of the new policy
- - if two hardware drivers failed to agree on a new policy before this
+2) And during CPUFREQ_NOTIFY all notifiers are informed of the new policy -
+ if two hardware drivers failed to agree on a new policy before this
stage, the incompatible hardware shall be shut down, and the user
informed of this.

The phase is specified in the second argument to the notifier.

-The third argument, a void *pointer, points to a struct cpufreq_policy
+The third argument, a `void *` pointer, points to a struct cpufreq_policy
consisting of several values, including min, max (the lower and upper
frequencies (in kHz) of the new policy).

@@ -88,23 +79,27 @@ CPUFREQ_POSTCHANGE.

The third argument is a struct cpufreq_freqs with the following
values:
-cpu - number of the affected CPU
-old - old frequency
-new - new frequency
-flags - flags of the cpufreq driver
+
+======= ===========================
+cpu number of the affected CPU
+old old frequency
+new new frequency
+flags flags of the cpufreq driver
+======= ===========================

3. CPUFreq Table Generation with Operating Performance Point (OPP)
==================================================================
For details about OPP, see Documentation/power/opp.txt

-dev_pm_opp_init_cpufreq_table -
+dev_pm_opp_init_cpufreq_table
This function provides a ready to use conversion routine to translate
the OPP layer's internal information about the available frequencies
into a format readily providable to cpufreq.

WARNING: Do not use this function in interrupt context.

- Example:
+ Example::
+
soc_pm_init()
{
/* Do things */
@@ -117,4 +112,5 @@ dev_pm_opp_init_cpufreq_table -
NOTE: This function is available only if CONFIG_CPU_FREQ is enabled in
addition to CONFIG_PM_OPP.

-dev_pm_opp_free_cpufreq_table - Free up the table allocated by dev_pm_opp_init_cpufreq_table
+dev_pm_opp_free_cpufreq_table
+ Free up the table allocated by dev_pm_opp_init_cpufreq_table
diff --git a/Documentation/cpu-freq/cpu-drivers.txt b/Documentation/cpu-freq/cpu-drivers.rst
similarity index 57%
rename from Documentation/cpu-freq/cpu-drivers.txt
rename to Documentation/cpu-freq/cpu-drivers.rst
index 6e353d00cdc6..9cc2559bc34b 100644
--- a/Documentation/cpu-freq/cpu-drivers.txt
+++ b/Documentation/cpu-freq/cpu-drivers.rst
@@ -1,35 +1,25 @@
- CPU frequency and voltage scaling code in the Linux(TM) kernel
-
-
- L i n u x C P U F r e q
-
- C P U D r i v e r s
-
- - information for developers -
-
-
- Dominik Brodowski <linux@brodo.de>
- Rafael J. Wysocki <rafael.j.wysocki@intel.com>
- Viresh Kumar <viresh.kumar@linaro.org>
-
-
-
- Clock scaling allows you to change the clock speed of the CPUs on the
- fly. This is a nice method to save battery power, because the lower
- the clock speed, the less power the CPU consumes.
-
-
-Contents:
----------
-1. What To Do?
-1.1 Initialization
-1.2 Per-CPU Initialization
-1.3 verify
-1.4 target/target_index or setpolicy?
-1.5 target/target_index
-1.6 setpolicy
-1.7 get_intermediate and target_intermediate
-2. Frequency Table Helpers
+===============================================
+How to implement a new cpufreq processor driver
+===============================================
+
+.. information for developers
+
+Authors:
+ - Dominik Brodowski <linux@brodo.de>
+ - Rafael J. Wysocki <rafael.j.wysocki@intel.com>
+ - Viresh Kumar <viresh.kumar@linaro.org>
+
+.. Contents:
+
+ 1. What To Do?
+ 1.1 Initialization
+ 1.2 Per-CPU Initialization
+ 1.3 verify
+ 1.4 target/target_index or setpolicy?
+ 1.5 target/target_index
+ 1.6 setpolicy
+ 1.7 get_intermediate and target_intermediate
+ 2. Frequency Table Helpers



@@ -46,59 +36,73 @@ on what is necessary:

First of all, in an __initcall level 7 (module_init()) or later
function check whether this kernel runs on the right CPU and the right
-chipset. If so, register a struct cpufreq_driver with the CPUfreq core
-using cpufreq_register_driver()
+chipset. If so, register a `struct cpufreq_driver` with the CPUfreq core
+using `cpufreq_register_driver()`

-What shall this struct cpufreq_driver contain?
+What shall this `struct cpufreq_driver` contain?

- .name - The name of this driver.
+.name
+ The name of this driver.

- .init - A pointer to the per-policy initialization function.
+.init
+ A pointer to the per-policy initialization function.

- .verify - A pointer to a "verification" function.
+.verify
+ A pointer to a "verification" function.

- .setpolicy _or_ .fast_switch _or_ .target _or_ .target_index - See
- below on the differences.
+.setpolicy **or** .fast_switch **or** .target **or** .target_index
+ See below on the differences.

And optionally

- .flags - Hints for the cpufreq core.
+.flags
+ Hints for the cpufreq core.

- .driver_data - cpufreq driver specific data.
+.driver_data
+ cpufreq driver specific data.

- .resolve_freq - Returns the most appropriate frequency for a target
- frequency. Doesn't change the frequency though.
+.resolve_freq
+ Returns the most appropriate frequency for a target
+ frequency. Doesn't change the frequency though.

- .get_intermediate and target_intermediate - Used to switch to stable
- frequency while changing CPU frequency.
+.get_intermediate and target_intermediate
+ Used to switch to stable frequency while changing CPU frequency.

- .get - Returns current frequency of the CPU.
+.get
+ Returns current frequency of the CPU.

- .bios_limit - Returns HW/BIOS max frequency limitations for the CPU.
+.bios_limit
+ Returns HW/BIOS max frequency limitations for the CPU.

- .exit - A pointer to a per-policy cleanup function called during
- CPU_POST_DEAD phase of cpu hotplug process.
+.exit
+ A pointer to a per-policy cleanup function called during
+ CPU_POST_DEAD phase of cpu hotplug process.

- .stop_cpu - A pointer to a per-policy stop function called during
- CPU_DOWN_PREPARE phase of cpu hotplug process.
+.stop_cpu
+ A pointer to a per-policy stop function called during
+ CPU_DOWN_PREPARE phase of cpu hotplug process.

- .suspend - A pointer to a per-policy suspend function which is called
- with interrupts disabled and _after_ the governor is stopped for the
- policy.
+.suspend
+ A pointer to a per-policy suspend function which is called with
+ interrupts disabled and **after** the governor is stopped for the policy.

- .resume - A pointer to a per-policy resume function which is called
- with interrupts disabled and _before_ the governor is started again.
+.resume
+ A pointer to a per-policy resume function which is called
+ with interrupts disabled and **before** the governor is started again.

- .ready - A pointer to a per-policy ready function which is called after
- the policy is fully initialized.
+.ready
+ A pointer to a per-policy ready function which is called after
+ the policy is fully initialized.

- .attr - A pointer to a NULL-terminated list of "struct freq_attr" which
- allow to export values to sysfs.
+.attr
+ A pointer to a NULL-terminated list of `struct freq_attr` which
+ allow to export values to sysfs.

- .boost_enabled - If set, boost frequencies are enabled.
+.boost_enabled
+ If set, boost frequencies are enabled.

- .set_boost - A pointer to a per-policy function to enable/disable boost
- frequencies.
+.set_boost
+ A pointer to a per-policy function to enable/disable boost frequencies.


1.2 Per-CPU Initialization
@@ -108,37 +112,42 @@ Whenever a new CPU is registered with the device model, or after the
cpufreq driver registers itself, the per-policy initialization function
cpufreq_driver.init is called if no cpufreq policy existed for the CPU.
Note that the .init() and .exit() routines are called only once for the
-policy and not for each CPU managed by the policy. It takes a struct
-cpufreq_policy *policy as argument. What to do now?
+policy and not for each CPU managed by the policy. It takes a `struct
+cpufreq_policy *policy` as argument. What to do now?

If necessary, activate the CPUfreq support on your CPU.

Then, the driver must fill in the following values:

-policy->cpuinfo.min_freq _and_
-policy->cpuinfo.max_freq - the minimum and maximum frequency
- (in kHz) which is supported by
- this CPU
-policy->cpuinfo.transition_latency the time it takes on this CPU to
- switch between two frequencies in
- nanoseconds (if appropriate, else
- specify CPUFREQ_ETERNAL)
-
-policy->cur The current operating frequency of
- this CPU (if appropriate)
-policy->min,
-policy->max,
-policy->policy and, if necessary,
-policy->governor must contain the "default policy" for
- this CPU. A few moments later,
- cpufreq_driver.verify and either
- cpufreq_driver.setpolicy or
- cpufreq_driver.target/target_index is called
- with these values.
-policy->cpus Update this with the masks of the
- (online + offline) CPUs that do DVFS
- along with this CPU (i.e. that share
- clock/voltage rails with it).
++---------------------------------------+--------------------------------------+
+| policy->cpuinfo.min_freq **and** | |
+| policy->cpuinfo.max_freq | the minimum and maximum frequency |
+| | (in kHz) which is supported by |
+| | this CPU |
++---------------------------------------+--------------------------------------+
+| policy->cpuinfo.transition_latency | the time it takes on this CPU to |
+| | switch between two frequencies in |
+| | nanoseconds (if appropriate, else |
+| | specify CPUFREQ_ETERNAL) |
++---------------------------------------+--------------------------------------+
+| policy->cur | The current operating frequency of |
+| | this CPU (if appropriate) |
++---------------------------------------+--------------------------------------+
+| policy->min, | |
+| policy->max, | |
+| policy->policy and, if necessary, | |
+| policy->governor | must contain the "default policy" |
+| | for this CPU. A few moments later, |
+| | cpufreq_driver.verify and either |
+| | cpufreq_driver.setpolicy or |
+| | cpufreq_driver.target/target_index |
+| | is called with these values. |
++---------------------------------------+--------------------------------------+
+| policy->cpus | Update this with the masks of the |
+| | (online + offline) CPUs that do DVFS |
+| | along with this CPU (i.e. that share |
+| | clock/voltage rails with it). |
++---------------------------------------+--------------------------------------+

For setting some of these values (cpuinfo.min[max]_freq, policy->min[max]), the
frequency table helpers might be helpful. See the section 2 for more information
@@ -151,8 +160,8 @@ on them.
When the user decides a new policy (consisting of
"policy,governor,min,max") shall be set, this policy must be validated
so that incompatible values can be corrected. For verifying these
-values cpufreq_verify_within_limits(struct cpufreq_policy *policy,
-unsigned int min_freq, unsigned int max_freq) function might be helpful.
+values `cpufreq_verify_within_limits(struct cpufreq_policy *policy,
+unsigned int min_freq, unsigned int max_freq)` function might be helpful.
See section 2 for details on frequency table helpers.

You need to make sure that at least one valid frequency (or operating
@@ -163,7 +172,7 @@ policy->max first, and only if this is no solution, decrease policy->min.
1.4 target or target_index or setpolicy or fast_switch?
-------------------------------------------------------

-Most cpufreq drivers or even most cpu frequency scaling algorithms
+Most cpufreq drivers or even most cpu frequency scaling algorithms
only allow the CPU frequency to be set to predefined fixed values. For
these, you use the ->target(), ->target_index() or ->fast_switch()
callbacks.
@@ -175,8 +184,8 @@ limits on their own. These shall use the ->setpolicy() callback.
1.5. target/target_index
------------------------

-The target_index call has two arguments: struct cpufreq_policy *policy,
-and unsigned int index (into the exposed frequency table).
+The target_index call has two arguments: `struct cpufreq_policy *policy`,
+and `unsigned int index` (into the exposed frequency table).

The CPUfreq driver must set the new frequency when called here. The
actual frequency must be determined by freq_table[index].frequency.
@@ -184,10 +193,10 @@ actual frequency must be determined by freq_table[index].frequency.
It should always restore to earlier frequency (i.e. policy->restore_freq) in
case of errors, even if we switched to intermediate frequency earlier.

-Deprecated:
+Deprecated
----------
-The target call has three arguments: struct cpufreq_policy *policy,
-unsigned int target_frequency, unsigned int relation.
+The target call has three arguments: `struct cpufreq_policy *policy`,
+`unsigned int target_frequency`, `unsigned int relation`.

The CPUfreq driver must set the new frequency when called here. The
actual frequency must be determined using the following rules:
@@ -210,14 +219,14 @@ Not all drivers are expected to implement it, as sleeping from within
this callback isn't allowed. This callback must be highly optimized to
do switching as fast as possible.

-This function has two arguments: struct cpufreq_policy *policy and
-unsigned int target_frequency.
+This function has two arguments: `struct cpufreq_policy *policy` and
+`unsigned int target_frequency`.


1.7 setpolicy
-------------

-The setpolicy call only takes a struct cpufreq_policy *policy as
+The setpolicy call only takes a `struct cpufreq_policy *policy` as
argument. You need to set the lower limit of the in-processor or
in-chipset dynamic frequency switching to policy->min, the upper limit
to policy->max, and -if supported- select a performance-oriented
@@ -278,10 +287,10 @@ table.

cpufreq_for_each_valid_entry(pos, table) - iterates over all entries,
excluding CPUFREQ_ENTRY_INVALID frequencies.
-Use arguments "pos" - a cpufreq_frequency_table * as a loop cursor and
-"table" - the cpufreq_frequency_table * you want to iterate over.
+Use arguments "pos" - a `cpufreq_frequency_table *` as a loop cursor and
+"table" - the `cpufreq_frequency_table *` you want to iterate over.

-For example:
+For example::

struct cpufreq_frequency_table *pos, *driver_freq_table;

diff --git a/Documentation/cpu-freq/cpufreq-nforce2.txt b/Documentation/cpu-freq/cpufreq-nforce2.rst
similarity index 65%
rename from Documentation/cpu-freq/cpufreq-nforce2.txt
rename to Documentation/cpu-freq/cpufreq-nforce2.rst
index babce1315026..d40700bd5083 100644
--- a/Documentation/cpu-freq/cpufreq-nforce2.txt
+++ b/Documentation/cpu-freq/cpufreq-nforce2.rst
@@ -1,3 +1,6 @@
+=================================
+nVidia nForce2 platform specifics
+=================================

The cpufreq-nforce2 driver changes the FSB on nVidia nForce2 platforms.

@@ -6,14 +9,15 @@ can be controlled independently from the PCI/AGP clock.

The module has two options:

+ ======== ======================================
fid: multiplier * 10 (for example 8.5 = 85)
min_fsb: minimum FSB
+ ======== ======================================

If not set, fid is calculated from the current CPU speed and the FSB.
min_fsb defaults to FSB at boot time - 50 MHz.

-IMPORTANT: The available range is limited downwards!
- Also the minimum available FSB can differ, for systems
+IMPORTANT:
+ The available range is limited downwards!
+ Also the minimum available FSB can differ, for systems
booting with 200 MHz, 150 should always work.
-
-
diff --git a/Documentation/cpu-freq/cpufreq-stats.rst b/Documentation/cpu-freq/cpufreq-stats.rst
new file mode 100644
index 000000000000..3e33712b496e
--- /dev/null
+++ b/Documentation/cpu-freq/cpufreq-stats.rst
@@ -0,0 +1,128 @@
+==========================================
+General description of sysfs cpufreq stats
+==========================================
+
+.. information for users
+
+
+Author: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
+
+.. Contents
+ 1. Introduction
+ 2. Statistics Provided (with example)
+ 3. Configuring cpufreq-stats
+
+
+1. Introduction
+===============
+
+cpufreq-stats is a driver that provides CPU frequency statistics for each CPU.
+These statistics are provided in /sysfs as a bunch of read_only interfaces. This
+interface (when configured) will appear in a separate directory under cpufreq
+in /sysfs (<sysfs root>/devices/system/cpu/cpuX/cpufreq/stats/) for each CPU.
+Various statistics will form read_only files under this directory.
+
+This driver is designed to be independent of any particular cpufreq_driver
+that may be running on your CPU. So, it will work with any cpufreq_driver.
+
+
+2. Statistics Provided (with example)
+=====================================
+
+cpufreq stats provides following statistics (explained in detail below).
+- time_in_state
+- total_trans
+- trans_table
+
+All the statistics will be from the time the stats driver has been inserted
+(or the time the stats were reset) to the time when a read of a particular
+statistic is done. Obviously, stats driver will not have any information
+about the frequency transitions before the stats driver insertion.
+
+::
+
+ <mysystem>:/sys/devices/system/cpu/cpu0/cpufreq/stats # ls -l
+ total 0
+ drwxr-xr-x 2 root root 0 May 14 16:06 .
+ drwxr-xr-x 3 root root 0 May 14 15:58 ..
+ --w------- 1 root root 4096 May 14 16:06 reset
+ -r--r--r-- 1 root root 4096 May 14 16:06 time_in_state
+ -r--r--r-- 1 root root 4096 May 14 16:06 total_trans
+ -r--r--r-- 1 root root 4096 May 14 16:06 trans_table
+
+reset
+ Write-only attribute that can be used to reset the stat counters. This can be
+ useful for evaluating system behaviour under different governors without the
+ need for a reboot.
+
+time_in_state
+ This gives the amount of time spent in each of the frequencies supported by
+ this CPU. The cat output will have "<frequency> <time>" pair in each line,
+ which will mean this CPU spent <time> usertime units of time at <frequency>.
+ Output will have one line for each of the supported frequencies. usertime
+ units here is 10mS (similar to other time exported in /proc).
+
+::
+
+ <mysystem>:/sys/devices/system/cpu/cpu0/cpufreq/stats # cat time_in_state
+ 3600000 2089
+ 3400000 136
+ 3200000 34
+ 3000000 67
+ 2800000 172488
+
+
+total_trans
+ This gives the total number of frequency transitions on this CPU. The cat
+ output will have a single count which is the total number of frequency
+ transitions.
+
+::
+
+ <mysystem>:/sys/devices/system/cpu/cpu0/cpufreq/stats # cat total_trans
+ 20
+
+trans_table
+ This will give a fine grained information about all the CPU frequency
+ transitions. The cat output here is a two dimensional matrix, where an entry
+ <i,j> (row i, column j) represents the count of number of transitions from
+ Freq_i to Freq_j. Freq_i rows and Freq_j columns follow the sorting order in
+ which the driver has provided the frequency table initially to the cpufreq
+ core and so can be sorted (ascending or descending) or unsorted. The output
+ here also contains the actual freq values for each row and column for better
+ readability.
+
+ If the transition table is bigger than PAGE_SIZE, reading this will
+ return an -EFBIG error.
+
+::
+
+ <mysystem>:/sys/devices/system/cpu/cpu0/cpufreq/stats # cat trans_table
+ From : To
+ : 3600000 3400000 3200000 3000000 2800000
+ 3600000: 0 5 0 0 0
+ 3400000: 4 0 2 0 0
+ 3200000: 0 1 0 2 0
+ 3000000: 0 0 1 0 3
+ 2800000: 0 0 0 2 0
+
+3. Configuring cpufreq-stats
+============================
+
+To configure cpufreq-stats in your kernel::
+
+ Config Main Menu
+ Power management options (ACPI, APM) --->
+ CPU Frequency scaling --->
+ [*] CPU Frequency scaling
+ [*] CPU frequency translation statistics
+
+
+"CPU Frequency scaling" (CONFIG_CPU_FREQ) should be enabled to configure
+cpufreq-stats.
+
+"CPU frequency translation statistics" (CONFIG_CPU_FREQ_STAT) provides the
+statistics which includes time_in_state, total_trans and trans_table.
+
+Once this option is enabled and your CPU supports cpufrequency, you
+will be able to see the CPU frequency statistics in /sysfs.
diff --git a/Documentation/cpu-freq/cpufreq-stats.txt b/Documentation/cpu-freq/cpufreq-stats.txt
deleted file mode 100644
index 14378cecb172..000000000000
--- a/Documentation/cpu-freq/cpufreq-stats.txt
+++ /dev/null
@@ -1,127 +0,0 @@
-
- CPU frequency and voltage scaling statistics in the Linux(TM) kernel
-
-
- L i n u x c p u f r e q - s t a t s d r i v e r
-
- - information for users -
-
-
- Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
-
-Contents
-1. Introduction
-2. Statistics Provided (with example)
-3. Configuring cpufreq-stats
-
-
-1. Introduction
-
-cpufreq-stats is a driver that provides CPU frequency statistics for each CPU.
-These statistics are provided in /sysfs as a bunch of read_only interfaces. This
-interface (when configured) will appear in a separate directory under cpufreq
-in /sysfs (<sysfs root>/devices/system/cpu/cpuX/cpufreq/stats/) for each CPU.
-Various statistics will form read_only files under this directory.
-
-This driver is designed to be independent of any particular cpufreq_driver
-that may be running on your CPU. So, it will work with any cpufreq_driver.
-
-
-2. Statistics Provided (with example)
-
-cpufreq stats provides following statistics (explained in detail below).
-- time_in_state
-- total_trans
-- trans_table
-
-All the statistics will be from the time the stats driver has been inserted
-(or the time the stats were reset) to the time when a read of a particular
-statistic is done. Obviously, stats driver will not have any information
-about the frequency transitions before the stats driver insertion.
-
---------------------------------------------------------------------------------
-<mysystem>:/sys/devices/system/cpu/cpu0/cpufreq/stats # ls -l
-total 0
-drwxr-xr-x 2 root root 0 May 14 16:06 .
-drwxr-xr-x 3 root root 0 May 14 15:58 ..
---w------- 1 root root 4096 May 14 16:06 reset
--r--r--r-- 1 root root 4096 May 14 16:06 time_in_state
--r--r--r-- 1 root root 4096 May 14 16:06 total_trans
--r--r--r-- 1 root root 4096 May 14 16:06 trans_table
---------------------------------------------------------------------------------
-
-- reset
-Write-only attribute that can be used to reset the stat counters. This can be
-useful for evaluating system behaviour under different governors without the
-need for a reboot.
-
-- time_in_state
-This gives the amount of time spent in each of the frequencies supported by
-this CPU. The cat output will have "<frequency> <time>" pair in each line, which
-will mean this CPU spent <time> usertime units of time at <frequency>. Output
-will have one line for each of the supported frequencies. usertime units here
-is 10mS (similar to other time exported in /proc).
-
---------------------------------------------------------------------------------
-<mysystem>:/sys/devices/system/cpu/cpu0/cpufreq/stats # cat time_in_state
-3600000 2089
-3400000 136
-3200000 34
-3000000 67
-2800000 172488
---------------------------------------------------------------------------------
-
-
-- total_trans
-This gives the total number of frequency transitions on this CPU. The cat
-output will have a single count which is the total number of frequency
-transitions.
-
---------------------------------------------------------------------------------
-<mysystem>:/sys/devices/system/cpu/cpu0/cpufreq/stats # cat total_trans
-20
---------------------------------------------------------------------------------
-
-- trans_table
-This will give a fine grained information about all the CPU frequency
-transitions. The cat output here is a two dimensional matrix, where an entry
-<i,j> (row i, column j) represents the count of number of transitions from
-Freq_i to Freq_j. Freq_i rows and Freq_j columns follow the sorting order in
-which the driver has provided the frequency table initially to the cpufreq core
-and so can be sorted (ascending or descending) or unsorted. The output here
-also contains the actual freq values for each row and column for better
-readability.
-
-If the transition table is bigger than PAGE_SIZE, reading this will
-return an -EFBIG error.
-
---------------------------------------------------------------------------------
-<mysystem>:/sys/devices/system/cpu/cpu0/cpufreq/stats # cat trans_table
- From : To
- : 3600000 3400000 3200000 3000000 2800000
- 3600000: 0 5 0 0 0
- 3400000: 4 0 2 0 0
- 3200000: 0 1 0 2 0
- 3000000: 0 0 1 0 3
- 2800000: 0 0 0 2 0
---------------------------------------------------------------------------------
-
-
-3. Configuring cpufreq-stats
-
-To configure cpufreq-stats in your kernel
-Config Main Menu
- Power management options (ACPI, APM) --->
- CPU Frequency scaling --->
- [*] CPU Frequency scaling
- [*] CPU frequency translation statistics
-
-
-"CPU Frequency scaling" (CONFIG_CPU_FREQ) should be enabled to configure
-cpufreq-stats.
-
-"CPU frequency translation statistics" (CONFIG_CPU_FREQ_STAT) provides the
-statistics which includes time_in_state, total_trans and trans_table.
-
-Once this option is enabled and your CPU supports cpufrequency, you
-will be able to see the CPU frequency statistics in /sysfs.
diff --git a/Documentation/cpu-freq/index.rst b/Documentation/cpu-freq/index.rst
new file mode 100644
index 000000000000..10e6c05f60f6
--- /dev/null
+++ b/Documentation/cpu-freq/index.rst
@@ -0,0 +1,52 @@
+:orphan:
+
+==============================================================
+CPU frequency and voltage scaling code in the Linux(TM) kernel
+==============================================================
+
+
+Author: Dominik Brodowski <linux@brodo.de>
+
+
+Clock scaling allows you to change the clock speed of the CPUs on the
+fly. This is a nice method to save battery power, because the lower
+the clock speed, the less power the CPU consumes.
+
+
+.. toctree::
+ :maxdepth: 1
+
+ core
+ cpufreq-stats
+ cpu-drivers
+
+ amd-powernow
+ cpufreq-nforce2
+ pcc-cpufreq
+
+.. only:: subproject and html
+
+ Indices
+ =======
+
+ * :ref:`genindex`
+
+Mailing List
+------------
+There is a CPU frequency changing CVS commit and general list where
+you can report bugs, problems or submit patches. To post a message,
+send an email to linux-pm@vger.kernel.org.
+
+Links
+-----
+the FTP archives:
+* ftp://ftp.linux.org.uk/pub/linux/cpufreq/
+
+how to access the CVS repository:
+* http://cvs.arm.linux.org.uk/
+
+the CPUFreq Mailing list:
+* http://vger.kernel.org/vger-lists.html#linux-pm
+
+Clock and voltage scaling for the SA-1100:
+* http://www.lartmaker.nl/projects/scaling
diff --git a/Documentation/cpu-freq/index.txt b/Documentation/cpu-freq/index.txt
deleted file mode 100644
index c15e75386a05..000000000000
--- a/Documentation/cpu-freq/index.txt
+++ /dev/null
@@ -1,56 +0,0 @@
- CPU frequency and voltage scaling code in the Linux(TM) kernel
-
-
- L i n u x C P U F r e q
-
-
-
-
- Dominik Brodowski <linux@brodo.de>
-
-
-
- Clock scaling allows you to change the clock speed of the CPUs on the
- fly. This is a nice method to save battery power, because the lower
- the clock speed, the less power the CPU consumes.
-
-
-
-Documents in this directory:
-----------------------------
-
-amd-powernow.txt - AMD powernow driver specific file.
-
-core.txt - General description of the CPUFreq core and
- of CPUFreq notifiers.
-
-cpu-drivers.txt - How to implement a new cpufreq processor driver.
-
-cpufreq-nforce2.txt - nVidia nForce2 platform specific file.
-
-cpufreq-stats.txt - General description of sysfs cpufreq stats.
-
-index.txt - File index, Mailing list and Links (this document)
-
-pcc-cpufreq.txt - PCC cpufreq driver specific file.
-
-
-Mailing List
-------------
-There is a CPU frequency changing CVS commit and general list where
-you can report bugs, problems or submit patches. To post a message,
-send an email to linux-pm@vger.kernel.org.
-
-Links
------
-the FTP archives:
-* ftp://ftp.linux.org.uk/pub/linux/cpufreq/
-
-how to access the CVS repository:
-* http://cvs.arm.linux.org.uk/
-
-the CPUFreq Mailing list:
-* http://vger.kernel.org/vger-lists.html#linux-pm
-
-Clock and voltage scaling for the SA-1100:
-* http://www.lartmaker.nl/projects/scaling
diff --git a/Documentation/cpu-freq/pcc-cpufreq.txt b/Documentation/cpu-freq/pcc-cpufreq.rst
similarity index 80%
rename from Documentation/cpu-freq/pcc-cpufreq.txt
rename to Documentation/cpu-freq/pcc-cpufreq.rst
index 9e3c3b33514c..d846a36536e4 100644
--- a/Documentation/cpu-freq/pcc-cpufreq.txt
+++ b/Documentation/cpu-freq/pcc-cpufreq.rst
@@ -1,45 +1,38 @@
-/*
- * pcc-cpufreq.txt - PCC interface documentation
- *
- * Copyright (C) 2009 Red Hat, Matthew Garrett <mjg@redhat.com>
- * Copyright (C) 2009 Hewlett-Packard Development Company, L.P.
- * Nagananda Chumbalkar <nagananda.chumbalkar@hp.com>
- *
- * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; version 2 of the License.
- *
- * This program is distributed in the hope that it will be useful, but
- * WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or NON
- * INFRINGEMENT. See the GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License along
- * with this program; if not, write to the Free Software Foundation, Inc.,
- * 675 Mass Ave, Cambridge, MA 02139, USA.
- *
- * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
- */
-
-
- Processor Clocking Control Driver
- ---------------------------------
-
-Contents:
----------
-1. Introduction
-1.1 PCC interface
-1.1.1 Get Average Frequency
-1.1.2 Set Desired Frequency
-1.2 Platforms affected
-2. Driver and /sys details
-2.1 scaling_available_frequencies
-2.2 cpuinfo_transition_latency
-2.3 cpuinfo_cur_freq
-2.4 related_cpus
-3. Caveats
+==========================================================
+Processor Clocking Control Driver cpufreq driver specifics
+==========================================================
+
+
+.. pcc-cpufreq.txt - PCC interface documentation
+
+ Copyright (C) 2009 Red Hat, Matthew Garrett <mjg@redhat.com>
+ Copyright (C) 2009 Hewlett-Packard Development Company, L.P.
+ Nagananda Chumbalkar <nagananda.chumbalkar@hp.com>
+
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; version 2 of the License.
+
+ This program is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or NON
+ INFRINGEMENT. See the GNU General Public License for more details.
+
+
+.. Contents:
+ 1. Introduction
+ 1.1 PCC interface
+ 1.1.1 Get Average Frequency
+ 1.1.2 Set Desired Frequency
+ 1.2 Platforms affected
+ 2. Driver and /sys details
+ 2.1 scaling_available_frequencies
+ 2.2 cpuinfo_transition_latency
+ 2.3 cpuinfo_cur_freq
+ 2.4 related_cpus
+ 3. Caveats

1. Introduction:
----------------
@@ -72,6 +65,7 @@ memory region. The shared memory region header contains the "command" and
doorbell.

The following commands are supported by the PCC interface:
+
* Get Average Frequency
* Set Desired Frequency

@@ -140,7 +134,9 @@ Internally, there is no need for the driver to convert the "target" frequency
to a corresponding P-state.

The VERSION number for the driver will be of the format v.xy.ab.
-eg: 1.00.02
+eg::
+
+ 1.00.02
----- --
| |
| -- this will increase with bug fixes/enhancements to the driver
@@ -168,21 +164,21 @@ A) Often cpuinfo_cur_freq will show a value different than what is declared
in the scaling_available_frequencies or scaling_cur_freq, or scaling_max_freq.
This is due to "turbo boost" available on recent Intel processors. If certain
conditions are met the BIOS can achieve a slightly higher speed than requested
-by OSPM. An example:
+by OSPM. An example::

-scaling_cur_freq : 2933000
-cpuinfo_cur_freq : 3196000
+ scaling_cur_freq : 2933000
+ cpuinfo_cur_freq : 3196000

B) There is a round-off error associated with the cpuinfo_cur_freq value.
Since the driver obtains the current frequency as a "percentage" (%) of the
nominal frequency from the BIOS, sometimes, the values displayed by
-scaling_cur_freq and cpuinfo_cur_freq may not match. An example:
+scaling_cur_freq and cpuinfo_cur_freq may not match. An example::

-scaling_cur_freq : 1600000
-cpuinfo_cur_freq : 1583000
+ scaling_cur_freq : 1600000
+ cpuinfo_cur_freq : 1583000

In this example, the nominal frequency is 2933 MHz. The driver obtains the
-current frequency, cpuinfo_cur_freq, as 54% of the nominal frequency:
+current frequency, cpuinfo_cur_freq, as 54% of the nominal frequency::

54% of 2933 MHz = 1583 MHz

@@ -191,10 +187,10 @@ corresponds to the frequency of the P0 P-state.

2.4 related_cpus:
-----------------
-The related_cpus field is identical to affected_cpus.
+The related_cpus field is identical to affected_cpus:

-affected_cpus : 4
-related_cpus : 4
+ affected_cpus : 4
+ related_cpus : 4

Currently, the PCC driver does not evaluate _PSD. The platforms that support
PCC do not implement SW_ALL. So OSPM doesn't need to perform any coordination
diff --git a/drivers/cpufreq/Kconfig.x86 b/drivers/cpufreq/Kconfig.x86
index 35f71825b7f3..c0c61edb8d93 100644
--- a/drivers/cpufreq/Kconfig.x86
+++ b/drivers/cpufreq/Kconfig.x86
@@ -24,7 +24,7 @@ config X86_PCC_CPUFREQ
This driver adds support for the PCC interface.

For details, take a look at:
- <file:Documentation/cpu-freq/pcc-cpufreq.txt>.
+ <file:Documentation/cpu-freq/pcc-cpufreq.rst>.

To compile this driver as a module, choose M here: the
module will be called pcc-cpufreq.
--
2.20.1
\
 
 \ /
  Last update: 2019-04-22 15:31    [W:0.607 / U:0.604 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site