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-rw-r--r--Documentation/cpu-freq/amd-powernow.txt38
-rw-r--r--Documentation/cpu-freq/core.txt98
-rw-r--r--Documentation/cpu-freq/cpu-drivers.txt216
-rw-r--r--Documentation/cpu-freq/cpufreq-nforce2.txt19
-rw-r--r--Documentation/cpu-freq/cpufreq-stats.txt128
-rw-r--r--Documentation/cpu-freq/governors.txt242
-rw-r--r--Documentation/cpu-freq/index.txt54
-rw-r--r--Documentation/cpu-freq/pcc-cpufreq.txt207
-rw-r--r--Documentation/cpu-freq/user-guide.txt224
9 files changed, 0 insertions, 1226 deletions
diff --git a/Documentation/cpu-freq/amd-powernow.txt b/Documentation/cpu-freq/amd-powernow.txt
deleted file mode 100644
index 254da155fa4..00000000000
--- a/Documentation/cpu-freq/amd-powernow.txt
+++ /dev/null
@@ -1,38 +0,0 @@
-
-PowerNow! and Cool'n'Quiet are AMD names for frequency
-management capabilities in AMD processors. As the hardware
-implementation changes in new generations of the processors,
-there is a different cpu-freq driver for each generation.
-
-Note that the driver's will not load on the "wrong" hardware,
-so it is safe to try each driver in turn when in doubt as to
-which is the correct driver.
-
-Note that the functionality to change frequency (and voltage)
-is not available in all processors. The drivers will refuse
-to load on processors without this capability. The capability
-is detected with the cpuid instruction.
-
-The drivers use BIOS supplied tables to obtain frequency and
-voltage information appropriate for a particular platform.
-Frequency transitions will be unavailable if the BIOS does
-not supply these tables.
-
-6th Generation: powernow-k6
-
-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.
-
-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
-of PSB support.
diff --git a/Documentation/cpu-freq/core.txt b/Documentation/cpu-freq/core.txt
deleted file mode 100644
index ce0666e5103..00000000000
--- a/Documentation/cpu-freq/core.txt
+++ /dev/null
@@ -1,98 +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
-
- C P U F r e q C o r e
-
-
- Dominik Brodowski <linux@brodo.de>
- David Kimdon <dwhedon@debian.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
-
-1. General Information
-=======================
-
-The CPUFreq core code is located in drivers/cpufreq/cpufreq.c. This
-cpufreq code offers a standardized interface for the CPUFreq
-architecture drivers (those pieces of code that do actual
-frequency transitions), as well as to "notifiers". These are device
-drivers or other part of the kernel that need to be informed of
-policy changes (ex. thermal modules like ACPI) or of all
-frequency changes (ex. timing code) or even need to force certain
-speed limits (like LCD drivers on ARM architecture). Additionally, the
-kernel "constant" loops_per_jiffy is updated on frequency changes
-here.
-
-Reference counting is done by cpufreq_get_cpu and cpufreq_put_cpu,
-which make sure that the cpufreq processor driver is correctly
-registered with the core, and will not be unloaded until
-cpufreq_put_cpu is called.
-
-2. CPUFreq notifiers
-====================
-
-CPUFreq notifiers conform to the standard kernel notifier interface.
-See linux/include/linux/notifier.h for details on notifiers.
-
-There are two different CPUFreq notifiers - policy notifiers and
-transition notifiers.
-
-
-2.1 CPUFreq policy notifiers
-----------------------------
-
-These are notified when a new policy is intended to be set. Each
-CPUFreq policy notifier is called three times 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.
-
-2.) During CPUFREQ_INCOMPATIBLE only changes may be done in order to avoid
- hardware failure.
-
-3.) 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
-consisting of five values: cpu, min, max, policy and max_cpu_freq. min
-and max are the lower and upper frequencies (in kHz) of the new
-policy, policy the new policy, cpu the number of the affected CPU; and
-max_cpu_freq the maximum supported CPU frequency. This value is given
-for informational purposes only.
-
-
-2.2 CPUFreq transition notifiers
---------------------------------
-
-These are notified twice when the CPUfreq driver switches the CPU core
-frequency and this change has any external implications.
-
-The second argument specifies the phase - CPUFREQ_PRECHANGE or
-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
-
-If the cpufreq core detects the frequency has changed while the system
-was suspended, these notifiers are called with CPUFREQ_RESUMECHANGE as
-second argument.
diff --git a/Documentation/cpu-freq/cpu-drivers.txt b/Documentation/cpu-freq/cpu-drivers.txt
deleted file mode 100644
index c436096351f..00000000000
--- a/Documentation/cpu-freq/cpu-drivers.txt
+++ /dev/null
@@ -1,216 +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
-
- C P U D r i v e r s
-
- - information for developers -
-
-
- 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.
-
-
-Contents:
----------
-1. What To Do?
-1.1 Initialization
-1.2 Per-CPU Initialization
-1.3 verify
-1.4 target or setpolicy?
-1.5 target
-1.6 setpolicy
-2. Frequency Table Helpers
-
-
-
-1. What To Do?
-==============
-
-So, you just got a brand-new CPU / chipset with datasheets and want to
-add cpufreq support for this CPU / chipset? Great. Here are some hints
-on what is necessary:
-
-
-1.1 Initialization
-------------------
-
-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()
-
-What shall this struct cpufreq_driver contain?
-
-cpufreq_driver.name - The name of this driver.
-
-cpufreq_driver.owner - THIS_MODULE;
-
-cpufreq_driver.init - A pointer to the per-CPU initialization
- function.
-
-cpufreq_driver.verify - A pointer to a "verification" function.
-
-cpufreq_driver.setpolicy _or_
-cpufreq_driver.target - See below on the differences.
-
-And optionally
-
-cpufreq_driver.exit - A pointer to a per-CPU cleanup function.
-
-cpufreq_driver.resume - A pointer to a per-CPU resume function
- which is called with interrupts disabled
- and _before_ the pre-suspend frequency
- and/or policy is restored by a call to
- ->target or ->setpolicy.
-
-cpufreq_driver.attr - A pointer to a NULL-terminated list of
- "struct freq_attr" which allow to
- export values to sysfs.
-
-
-1.2 Per-CPU Initialization
---------------------------
-
-Whenever a new CPU is registered with the device model, or after the
-cpufreq driver registers itself, the per-CPU initialization function
-cpufreq_driver.init is called. 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 is called with
- these values.
-
-For setting some of these values, the frequency table helpers might be
-helpful. See the section 2 for more information on them.
-
-
-1.3 verify
-------------
-
-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, a frequency table helper and/or the
-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
-range) is within policy->min and policy->max. If necessary, increase
-policy->max first, and only if this is no solution, decrease policy->min.
-
-
-1.4 target or setpolicy?
-----------------------------
-
-Most cpufreq drivers or even most cpu frequency scaling algorithms
-only allow the CPU to be set to one frequency. For these, you use the
-->target call.
-
-Some cpufreq-capable processors switch the frequency between certain
-limits on their own. These shall use the ->setpolicy call
-
-
-1.4. target
--------------
-
-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:
-
-- keep close to "target_freq"
-- policy->min <= new_freq <= policy->max (THIS MUST BE VALID!!!)
-- if relation==CPUFREQ_REL_L, try to select a new_freq higher than or equal
- target_freq. ("L for lowest, but no lower than")
-- if relation==CPUFREQ_REL_H, try to select a new_freq lower than or equal
- target_freq. ("H for highest, but no higher than")
-
-Here again the frequency table helper might assist you - see section 2
-for details.
-
-
-1.5 setpolicy
----------------
-
-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
-setting when policy->policy is CPUFREQ_POLICY_PERFORMANCE, and a
-powersaving-oriented setting when CPUFREQ_POLICY_POWERSAVE. Also check
-the reference implementation in drivers/cpufreq/longrun.c
-
-
-
-2. Frequency Table Helpers
-==========================
-
-As most cpufreq processors only allow for being set to a few specific
-frequencies, a "frequency table" with some functions might assist in
-some work of the processor driver. Such a "frequency table" consists
-of an array of struct cpufreq_freq_table entries, with any value in
-"index" you want to use, and the corresponding frequency in
-"frequency". At the end of the table, you need to add a
-cpufreq_freq_table entry with frequency set to CPUFREQ_TABLE_END. And
-if you want to skip one entry in the table, set the frequency to
-CPUFREQ_ENTRY_INVALID. The entries don't need to be in ascending
-order.
-
-By calling cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
- struct cpufreq_frequency_table *table);
-the cpuinfo.min_freq and cpuinfo.max_freq values are detected, and
-policy->min and policy->max are set to the same values. This is
-helpful for the per-CPU initialization stage.
-
-int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
- struct cpufreq_frequency_table *table);
-assures that at least one valid frequency is within policy->min and
-policy->max, and all other criteria are met. This is helpful for the
-->verify call.
-
-int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
- struct cpufreq_frequency_table *table,
- unsigned int target_freq,
- unsigned int relation,
- unsigned int *index);
-
-is the corresponding frequency table helper for the ->target
-stage. Just pass the values to this function, and the unsigned int
-index returns the number of the frequency table entry which contains
-the frequency the CPU shall be set to. PLEASE NOTE: This is not the
-"index" which is in this cpufreq_table_entry.index, but instead
-cpufreq_table[index]. So, the new frequency is
-cpufreq_table[index].frequency, and the value you stored into the
-frequency table "index" field is
-cpufreq_table[index].index.
-
diff --git a/Documentation/cpu-freq/cpufreq-nforce2.txt b/Documentation/cpu-freq/cpufreq-nforce2.txt
deleted file mode 100644
index babce131502..00000000000
--- a/Documentation/cpu-freq/cpufreq-nforce2.txt
+++ /dev/null
@@ -1,19 +0,0 @@
-
-The cpufreq-nforce2 driver changes the FSB on nVidia nForce2 platforms.
-
-This works better than on other platforms, because the FSB of the CPU
-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
- booting with 200 MHz, 150 should always work.
-
-
diff --git a/Documentation/cpu-freq/cpufreq-stats.txt b/Documentation/cpu-freq/cpufreq-stats.txt
deleted file mode 100644
index fc647492e94..00000000000
--- a/Documentation/cpu-freq/cpufreq-stats.txt
+++ /dev/null
@@ -1,128 +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
-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 ..
--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
---------------------------------------------------------------------------------
-
-- 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 is in descending order with increasing rows and
-Freq_j is in descending order with increasing columns. The output here also
-contains the actual freq values for each row and column for better readability.
-
---------------------------------------------------------------------------------
-<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 translation statistics details
-
-
-"CPU Frequency scaling" (CONFIG_CPU_FREQ) should be enabled to configure
-cpufreq-stats.
-
-"CPU frequency translation statistics" (CONFIG_CPU_FREQ_STAT) provides the
-basic statistics which includes time_in_state and total_trans.
-
-"CPU frequency translation statistics details" (CONFIG_CPU_FREQ_STAT_DETAILS)
-provides fine grained cpufreq stats by trans_table. The reason for having a
-separate config option for trans_table is:
-- trans_table goes against the traditional /sysfs rule of one value per
- interface. It provides a whole bunch of value in a 2 dimensional matrix
- form.
-
-Once these two options are enabled and your CPU supports cpufrequency, you
-will be able to see the CPU frequency statistics in /sysfs.
-
-
-
-
diff --git a/Documentation/cpu-freq/governors.txt b/Documentation/cpu-freq/governors.txt
deleted file mode 100644
index c7a2eb8450c..00000000000
--- a/Documentation/cpu-freq/governors.txt
+++ /dev/null
@@ -1,242 +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
-
- C P U F r e q G o v e r n o r s
-
- - information for users and developers -
-
-
- Dominik Brodowski <linux@brodo.de>
- some additions and corrections by Nico Golde <nico@ngolde.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.
-
-
-Contents:
----------
-1. What is a CPUFreq Governor?
-
-2. Governors In the Linux Kernel
-2.1 Performance
-2.2 Powersave
-2.3 Userspace
-2.4 Ondemand
-2.5 Conservative
-
-3. The Governor Interface in the CPUfreq Core
-
-
-
-1. What Is A CPUFreq Governor?
-==============================
-
-Most cpufreq drivers (in fact, all except one, longrun) or even most
-cpu frequency scaling algorithms only offer the CPU to be set to one
-frequency. In order to offer dynamic frequency scaling, the cpufreq
-core must be able to tell these drivers of a "target frequency". So
-these specific drivers will be transformed to offer a "->target"
-call instead of the existing "->setpolicy" call. For "longrun", all
-stays the same, though.
-
-How to decide what frequency within the CPUfreq policy should be used?
-That's done using "cpufreq governors". Two are already in this patch
--- they're the already existing "powersave" and "performance" which
-set the frequency statically to the lowest or highest frequency,
-respectively. At least two more such governors will be ready for
-addition in the near future, but likely many more as there are various
-different theories and models about dynamic frequency scaling
-around. Using such a generic interface as cpufreq offers to scaling
-governors, these can be tested extensively, and the best one can be
-selected for each specific use.
-
-Basically, it's the following flow graph:
-
-CPU can be set to switch independently | CPU can only be set
- within specific "limits" | to specific frequencies
-
- "CPUfreq policy"
- consists of frequency limits (policy->{min,max})
- and CPUfreq governor to be used
- / \
- / \
- / the cpufreq governor decides
- / (dynamically or statically)
- / what target_freq to set within
- / the limits of policy->{min,max}
- / \
- / \
- Using the ->setpolicy call, Using the ->target call,
- the limits and the the frequency closest
- "policy" is set. to target_freq is set.
- It is assured that it
- is within policy->{min,max}
-
-
-2. Governors In the Linux Kernel
-================================
-
-2.1 Performance
----------------
-
-The CPUfreq governor "performance" sets the CPU statically to the
-highest frequency within the borders of scaling_min_freq and
-scaling_max_freq.
-
-
-2.2 Powersave
--------------
-
-The CPUfreq governor "powersave" sets the CPU statically to the
-lowest frequency within the borders of scaling_min_freq and
-scaling_max_freq.
-
-
-2.3 Userspace
--------------
-
-The CPUfreq governor "userspace" allows the user, or any userspace
-program running with UID "root", to set the CPU to a specific frequency
-by making a sysfs file "scaling_setspeed" available in the CPU-device
-directory.
-
-
-2.4 Ondemand
-------------
-
-The CPUfreq governor "ondemand" sets the CPU depending on the
-current usage. To do this the CPU must have the capability to
-switch the frequency very quickly. There are a number of sysfs file
-accessible parameters:
-
-sampling_rate: measured in uS (10^-6 seconds), this is how often you
-want the kernel to look at the CPU usage and to make decisions on
-what to do about the frequency. Typically this is set to values of
-around '10000' or more. It's default value is (cmp. with users-guide.txt):
-transition_latency * 1000
-Be aware that transition latency is in ns and sampling_rate is in us, so you
-get the same sysfs value by default.
-Sampling rate should always get adjusted considering the transition latency
-To set the sampling rate 750 times as high as the transition latency
-in the bash (as said, 1000 is default), do:
-echo `$(($(cat cpuinfo_transition_latency) * 750 / 1000)) \
- >ondemand/sampling_rate
-
-sampling_rate_min:
-The sampling rate is limited by the HW transition latency:
-transition_latency * 100
-Or by kernel restrictions:
-If CONFIG_NO_HZ is set, the limit is 10ms fixed.
-If CONFIG_NO_HZ is not set or nohz=off boot parameter is used, the
-limits depend on the CONFIG_HZ option:
-HZ=1000: min=20000us (20ms)
-HZ=250: min=80000us (80ms)
-HZ=100: min=200000us (200ms)
-The highest value of kernel and HW latency restrictions is shown and
-used as the minimum sampling rate.
-
-up_threshold: defines what the average CPU usage between the samplings
-of 'sampling_rate' needs to be for the kernel to make a decision on
-whether it should increase the frequency. For example when it is set
-to its default value of '95' it means that between the checking
-intervals the CPU needs to be on average more than 95% in use to then
-decide that the CPU frequency needs to be increased.
-
-ignore_nice_load: this parameter takes a value of '0' or '1'. When
-set to '0' (its default), all processes are counted towards the
-'cpu utilisation' value. When set to '1', the processes that are
-run with a 'nice' value will not count (and thus be ignored) in the
-overall usage calculation. This is useful if you are running a CPU
-intensive calculation on your laptop that you do not care how long it
-takes to complete as you can 'nice' it and prevent it from taking part
-in the deciding process of whether to increase your CPU frequency.
-
-sampling_down_factor: this parameter controls the rate at which the
-kernel makes a decision on when to decrease the frequency while running
-at top speed. When set to 1 (the default) decisions to reevaluate load
-are made at the same interval regardless of current clock speed. But
-when set to greater than 1 (e.g. 100) it acts as a multiplier for the
-scheduling interval for reevaluating load when the CPU is at its top
-speed due to high load. This improves performance by reducing the overhead
-of load evaluation and helping the CPU stay at its top speed when truly
-busy, rather than shifting back and forth in speed. This tunable has no
-effect on behavior at lower speeds/lower CPU loads.
-
-
-2.5 Conservative
-----------------
-
-The CPUfreq governor "conservative", much like the "ondemand"
-governor, sets the CPU depending on the current usage. It differs in
-behaviour in that it gracefully increases and decreases the CPU speed
-rather than jumping to max speed the moment there is any load on the
-CPU. This behaviour more suitable in a battery powered environment.
-The governor is tweaked in the same manner as the "ondemand" governor
-through sysfs with the addition of:
-
-freq_step: this describes what percentage steps the cpu freq should be
-increased and decreased smoothly by. By default the cpu frequency will
-increase in 5% chunks of your maximum cpu frequency. You can change this
-value to anywhere between 0 and 100 where '0' will effectively lock your
-CPU at a speed regardless of its load whilst '100' will, in theory, make
-it behave identically to the "ondemand" governor.
-
-down_threshold: same as the 'up_threshold' found for the "ondemand"
-governor but for the opposite direction. For example when set to its
-default value of '20' it means that if the CPU usage needs to be below
-20% between samples to have the frequency decreased.
-
-3. The Governor Interface in the CPUfreq Core
-=============================================
-
-A new governor must register itself with the CPUfreq core using
-"cpufreq_register_governor". The struct cpufreq_governor, which has to
-be passed to that function, must contain the following values:
-
-governor->name - A unique name for this governor
-governor->governor - The governor callback function
-governor->owner - .THIS_MODULE for the governor module (if
- appropriate)
-
-The governor->governor callback is called with the current (or to-be-set)
-cpufreq_policy struct for that CPU, and an unsigned int event. The
-following events are currently defined:
-
-CPUFREQ_GOV_START: This governor shall start its duty for the CPU
- policy->cpu
-CPUFREQ_GOV_STOP: This governor shall end its duty for the CPU
- policy->cpu
-CPUFREQ_GOV_LIMITS: The limits for CPU policy->cpu have changed to
- policy->min and policy->max.
-
-If you need other "events" externally of your driver, _only_ use the
-cpufreq_governor_l(unsigned int cpu, unsigned int event) call to the
-CPUfreq core to ensure proper locking.
-
-
-The CPUfreq governor may call the CPU processor driver using one of
-these two functions:
-
-int cpufreq_driver_target(struct cpufreq_policy *policy,
- unsigned int target_freq,
- unsigned int relation);
-
-int __cpufreq_driver_target(struct cpufreq_policy *policy,
- unsigned int target_freq,
- unsigned int relation);
-
-target_freq must be within policy->min and policy->max, of course.
-What's the difference between these two functions? When your governor
-still is in a direct code path of a call to governor->governor, the
-per-CPU cpufreq lock is still held in the cpufreq core, and there's
-no need to lock it again (in fact, this would cause a deadlock). So
-use __cpufreq_driver_target only in these cases. In all other cases
-(for example, when there's a "daemonized" function that wakes up
-every second), use cpufreq_driver_target to lock the cpufreq per-CPU
-lock before the command is passed to the cpufreq processor driver.
-
diff --git a/Documentation/cpu-freq/index.txt b/Documentation/cpu-freq/index.txt
deleted file mode 100644
index 3d0b915035b..00000000000
--- a/Documentation/cpu-freq/index.txt
+++ /dev/null
@@ -1,54 +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:
-----------------------------
-core.txt - General description of the CPUFreq core and
- of CPUFreq notifiers
-
-cpu-drivers.txt - How to implement a new cpufreq processor driver
-
-governors.txt - What are cpufreq governors and how to
- implement them?
-
-index.txt - File index, Mailing list and Links (this document)
-
-user-guide.txt - User Guide to CPUFreq
-
-
-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 cpufreq@vger.kernel.org, to subscribe go to
-http://vger.kernel.org/vger-lists.html#cpufreq and follow the
-instructions there.
-
-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#cpufreq
-
-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.txt
deleted file mode 100644
index 9e3c3b33514..00000000000
--- a/Documentation/cpu-freq/pcc-cpufreq.txt
+++ /dev/null
@@ -1,207 +0,0 @@
-/*
- * 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
-
-1. Introduction:
-----------------
-Processor Clocking Control (PCC) is an interface between the platform
-firmware and OSPM. It is a mechanism for coordinating processor
-performance (ie: frequency) between the platform firmware and the OS.
-
-The PCC driver (pcc-cpufreq) allows OSPM to take advantage of the PCC
-interface.
-
-OS utilizes the PCC interface to inform platform firmware what frequency the
-OS wants for a logical processor. The platform firmware attempts to achieve
-the requested frequency. If the request for the target frequency could not be
-satisfied by platform firmware, then it usually means that power budget
-conditions are in place, and "power capping" is taking place.
-
-1.1 PCC interface:
-------------------
-The complete PCC specification is available here:
-http://www.acpica.org/download/Processor-Clocking-Control-v1p0.pdf
-
-PCC relies on a shared memory region that provides a channel for communication
-between the OS and platform firmware. PCC also implements a "doorbell" that
-is used by the OS to inform the platform firmware that a command has been
-sent.
-
-The ACPI PCCH() method is used to discover the location of the PCC shared
-memory region. The shared memory region header contains the "command" and
-"status" interface. PCCH() also contains details on how to access the platform
-doorbell.
-
-The following commands are supported by the PCC interface:
-* Get Average Frequency
-* Set Desired Frequency
-
-The ACPI PCCP() method is implemented for each logical processor and is
-used to discover the offsets for the input and output buffers in the shared
-memory region.
-
-When PCC mode is enabled, the platform will not expose processor performance
-or throttle states (_PSS, _TSS and related ACPI objects) to OSPM. Therefore,
-the native P-state driver (such as acpi-cpufreq for Intel, powernow-k8 for
-AMD) will not load.
-
-However, OSPM remains in control of policy. The governor (eg: "ondemand")
-computes the required performance for each processor based on server workload.
-The PCC driver fills in the command interface, and the input buffer and
-communicates the request to the platform firmware. The platform firmware is
-responsible for delivering the requested performance.
-
-Each PCC command is "global" in scope and can affect all the logical CPUs in
-the system. Therefore, PCC is capable of performing "group" updates. With PCC
-the OS is capable of getting/setting the frequency of all the logical CPUs in
-the system with a single call to the BIOS.
-
-1.1.1 Get Average Frequency:
-----------------------------
-This command is used by the OSPM to query the running frequency of the
-processor since the last time this command was completed. The output buffer
-indicates the average unhalted frequency of the logical processor expressed as
-a percentage of the nominal (ie: maximum) CPU frequency. The output buffer
-also signifies if the CPU frequency is limited by a power budget condition.
-
-1.1.2 Set Desired Frequency:
-----------------------------
-This command is used by the OSPM to communicate to the platform firmware the
-desired frequency for a logical processor. The output buffer is currently
-ignored by OSPM. The next invocation of "Get Average Frequency" will inform
-OSPM if the desired frequency was achieved or not.
-
-1.2 Platforms affected:
------------------------
-The PCC driver will load on any system where the platform firmware:
-* supports the PCC interface, and the associated PCCH() and PCCP() methods
-* assumes responsibility for managing the hardware clocking controls in order
-to deliver the requested processor performance
-
-Currently, certain HP ProLiant platforms implement the PCC interface. On those
-platforms PCC is the "default" choice.
-
-However, it is possible to disable this interface via a BIOS setting. In
-such an instance, as is also the case on platforms where the PCC interface
-is not implemented, the PCC driver will fail to load silently.
-
-2. Driver and /sys details:
----------------------------
-When the driver loads, it merely prints the lowest and the highest CPU
-frequencies supported by the platform firmware.
-
-The PCC driver loads with a message such as:
-pcc-cpufreq: (v1.00.00) driver loaded with frequency limits: 1600 MHz, 2933
-MHz
-
-This means that the OPSM can request the CPU to run at any frequency in
-between the limits (1600 MHz, and 2933 MHz) specified in the message.
-
-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
- ----- --
- | |
- | -- this will increase with bug fixes/enhancements to the driver
- |-- this is the version of the PCC specification the driver adheres to
-
-
-The following is a brief discussion on some of the fields exported via the
-/sys filesystem and how their values are affected by the PCC driver:
-
-2.1 scaling_available_frequencies:
-----------------------------------
-scaling_available_frequencies is not created in /sys. No intermediate
-frequencies need to be listed because the BIOS will try to achieve any
-frequency, within limits, requested by the governor. A frequency does not have
-to be strictly associated with a P-state.
-
-2.2 cpuinfo_transition_latency:
--------------------------------
-The cpuinfo_transition_latency field is 0. The PCC specification does
-not include a field to expose this value currently.
-
-2.3 cpuinfo_cur_freq:
----------------------
-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:
-
-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 : 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:
-
- 54% of 2933 MHz = 1583 MHz
-
-Nominal frequency is the maximum frequency of the processor, and it usually
-corresponds to the frequency of the P0 P-state.
-
-2.4 related_cpus:
------------------
-The related_cpus field is identical to affected_cpus.
-
-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
-to ensure that the same frequency is requested of all dependent CPUs.
-
-3. Caveats:
------------
-The "cpufreq_stats" module in its present form cannot be loaded and
-expected to work with the PCC driver. Since the "cpufreq_stats" module
-provides information wrt each P-state, it is not applicable to the PCC driver.
diff --git a/Documentation/cpu-freq/user-guide.txt b/Documentation/cpu-freq/user-guide.txt
deleted file mode 100644
index 04f6b32993e..00000000000
--- a/Documentation/cpu-freq/user-guide.txt
+++ /dev/null
@@ -1,224 +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
-
- U S E R G U I D E
-
-
- 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.
-
-
-Contents:
----------
-1. Supported Architectures and Processors
-1.1 ARM
-1.2 x86
-1.3 sparc64
-1.4 ppc
-1.5 SuperH
-1.6 Blackfin
-
-2. "Policy" / "Governor"?
-2.1 Policy
-2.2 Governor
-
-3. How to change the CPU cpufreq policy and/or speed
-3.1 Preferred interface: sysfs
-
-
-
-1. Supported Architectures and Processors
-=========================================
-
-1.1 ARM
--------
-
-The following ARM processors are supported by cpufreq:
-
-ARM Integrator
-ARM-SA1100
-ARM-SA1110
-Intel PXA
-
-
-1.2 x86
--------
-
-The following processors for the x86 architecture are supported by cpufreq:
-
-AMD Elan - SC400, SC410
-AMD mobile K6-2+
-AMD mobile K6-3+
-AMD mobile Duron
-AMD mobile Athlon
-AMD Opteron
-AMD Athlon 64
-Cyrix Media GXm
-Intel mobile PIII and Intel mobile PIII-M on certain chipsets
-Intel Pentium 4, Intel Xeon
-Intel Pentium M (Centrino)
-National Semiconductors Geode GX
-Transmeta Crusoe
-Transmeta Efficeon
-VIA Cyrix 3 / C3
-various processors on some ACPI 2.0-compatible systems [*]
-
-[*] Only if "ACPI Processor Performance States" are available
-to the ACPI<->BIOS interface.
-
-
-1.3 sparc64
------------
-
-The following processors for the sparc64 architecture are supported by
-cpufreq:
-
-UltraSPARC-III
-
-
-1.4 ppc
--------
-
-Several "PowerBook" and "iBook2" notebooks are supported.
-
-
-1.5 SuperH
-----------
-
-All SuperH processors supporting rate rounding through the clock
-framework are supported by cpufreq.
-
-1.6 Blackfin
-------------
-
-The following Blackfin processors are supported by cpufreq:
-
-BF522, BF523, BF524, BF525, BF526, BF527, Rev 0.1 or higher
-BF531, BF532, BF533, Rev 0.3 or higher
-BF534, BF536, BF537, Rev 0.2 or higher
-BF561, Rev 0.3 or higher
-BF542, BF544, BF547, BF548, BF549, Rev 0.1 or higher
-
-
-2. "Policy" / "Governor" ?
-==========================
-
-Some CPU frequency scaling-capable processor switch between various
-frequencies and operating voltages "on the fly" without any kernel or
-user involvement. This guarantees very fast switching to a frequency
-which is high enough to serve the user's needs, but low enough to save
-power.
-
-
-2.1 Policy
-----------
-
-On these systems, all you can do is select the lower and upper
-frequency limit as well as whether you want more aggressive
-power-saving or more instantly available processing power.
-
-
-2.2 Governor
-------------
-
-On all other cpufreq implementations, these boundaries still need to
-be set. Then, a "governor" must be selected. Such a "governor" decides
-what speed the processor shall run within the boundaries. One such
-"governor" is the "userspace" governor. This one allows the user - or
-a yet-to-implement userspace program - to decide what specific speed
-the processor shall run at.
-
-
-3. How to change the CPU cpufreq policy and/or speed
-====================================================
-
-3.1 Preferred Interface: sysfs
-------------------------------
-
-The preferred interface is located in the sysfs filesystem. If you
-mounted it at /sys, the cpufreq interface is located in a subdirectory
-"cpufreq" within the cpu-device directory
-(e.g. /sys/devices/system/cpu/cpu0/cpufreq/ for the first CPU).
-
-cpuinfo_min_freq : this file shows the minimum operating
- frequency the processor can run at(in kHz)
-cpuinfo_max_freq : this file shows the maximum operating
- frequency the processor can run at(in kHz)
-cpuinfo_transition_latency The time it takes on this CPU to
- switch between two frequencies in nano
- seconds. If unknown or known to be
- that high that the driver does not
- work with the ondemand governor, -1
- (CPUFREQ_ETERNAL) will be returned.
- Using this information can be useful
- to choose an appropriate polling
- frequency for a kernel governor or
- userspace daemon. Make sure to not
- switch the frequency too often
- resulting in performance loss.
-scaling_driver : this file shows what cpufreq driver is
- used to set the frequency on this CPU
-
-scaling_available_governors : this file shows the CPUfreq governors
- available in this kernel. You can see the
- currently activated governor in
-
-scaling_governor, and by "echoing" the name of another
- governor you can change it. Please note
- that some governors won't load - they only
- work on some specific architectures or
- processors.
-
-cpuinfo_cur_freq : Current frequency of the CPU as obtained from
- the hardware, in KHz. This is the frequency
- the CPU actually runs at.
-
-scaling_available_frequencies : List of available frequencies, in KHz.
-
-scaling_min_freq and
-scaling_max_freq show the current "policy limits" (in
- kHz). By echoing new values into these
- files, you can change these limits.
- NOTE: when setting a policy you need to
- first set scaling_max_freq, then
- scaling_min_freq.
-
-affected_cpus : List of CPUs that require software coordination
- of frequency.
-
-related_cpus : List of CPUs that need some sort of frequency
- coordination, whether software or hardware.
-
-scaling_driver : Hardware driver for cpufreq.
-
-scaling_cur_freq : Current frequency of the CPU as determined by
- the governor and cpufreq core, in KHz. This is
- the frequency the kernel thinks the CPU runs
- at.
-
-bios_limit : If the BIOS tells the OS to limit a CPU to
- lower frequencies, the user can read out the
- maximum available frequency from this file.
- This typically can happen through (often not
- intended) BIOS settings, restrictions
- triggered through a service processor or other
- BIOS/HW based implementations.
- This does not cover thermal ACPI limitations
- which can be detected through the generic
- thermal driver.
-
-If you have selected the "userspace" governor which allows you to
-set the CPU operating frequency to a specific value, you can read out
-the current frequency in
-
-scaling_setspeed. By "echoing" a new frequency into this
- you can change the speed of the CPU,
- but only within the limits of
- scaling_min_freq and scaling_max_freq.