The relation should be CPUFREQ_RELATION_L to find optimal frequency
when decreasing.
Signed-off-by: NNamhyung Kim <namhyung@kernel.org>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

If we're on the lowest frequency, no need to calculate new freq.
Break out even earlier in this case.
Signed-off-by: NNamhyung Kim <namhyung@kernel.org>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Following patch has introduced per cpu timers or works for ondemand and
conservative governors.

	commit 2abfa876
	Author: Rickard Andersson <rickard.andersson@stericsson.com>
	Date:   Thu Dec 27 14:55:38 2012 +0000

	    cpufreq: handle SW coordinated CPUs

This causes additional unnecessary interrupts on all cpus when the load is
recently evaluated by any other cpu. i.e. When load is recently evaluated by cpu
x, we don't really need any other cpu to evaluate this load again for the next
sampling_rate time.

Some sort of code is present to avoid that but we are still getting timer
interrupts for all cpus. A good way of avoiding this would be to modify delays
for all cpus (policy->cpus) whenever any cpu has evaluated load.

This patch does this change and some related code cleanup.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Because we have per cpu timer now, we check if we need to evaluate load again or
not (In case it is recently evaluated). Here the 2nd cpu which got timer
interrupt updates core_dbs_info->sample_type irrespective of load evaluation is
required or not. Which is wrong as the first cpu is dependent on this variable
set to an older value.

Moreover it would be best in this case to schedule 2nd cpu's timer to
sampling_rate instead of freq_lo or hi as that must be managed by the other cpu.
In case the other cpu idles in between then also we wouldn't loose much power.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Currently MIN_LATENCY_MULTIPLIER is set defined as 100 and so on a system with
transition latency of 1 ms, the minimum sampling time comes to be around 100 ms.
That is quite big if you want to get better performance for your system.

Redefine MIN_LATENCY_MULTIPLIER to 20 so that we can support 20ms sampling rate
for such platforms.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Currently, there can't be multiple instances of single governor_type.
If we have a multi-package system, where we have multiple instances
of struct policy (per package), we can't have multiple instances of
same governor. i.e. We can't have multiple instances of ondemand
governor for multiple packages.

Governors directory in sysfs is created at /sys/devices/system/cpu/cpufreq/
governor-name/. Which again reflects that there can be only one
instance of a governor_type in the system.

This is a bottleneck for multicluster system, where we want different
packages to use same governor type, but with different tunables.

This patch uses the infrastructure provided by earlier patch and
implements init/exit routines for ondemand and conservative
governors.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Currently, there can't be multiple instances of single governor_type.
If we have a multi-package system, where we have multiple instances
of struct policy (per package), we can't have multiple instances of
same governor. i.e. We can't have multiple instances of ondemand
governor for multiple packages.

Governors directory in sysfs is created at /sys/devices/system/cpu/cpufreq/
governor-name/. Which again reflects that there can be only one
instance of a governor_type in the system.

This is a bottleneck for multicluster system, where we want different
packages to use same governor type, but with different tunables.

This patch is inclined towards providing this infrastructure. Because
we are required to allocate governor's resources dynamically now, we
must do it at policy creation and end. And so got
CPUFREQ_GOV_POLICY_INIT/EXIT.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

This eliminates the contention I am seeing in __cpufreq_cpu_get.
It also nicely stages the lock to be replaced by the rcu.
Signed-off-by: NNathan Zimmer <nzimmer@sgi.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

With the addition of following patch:

fcf80582 cpufreq: Simplify cpufreq_add_dev()

cpufreq driver's .init() routine must initialize policy->cpus with
mask of all possible CPUs (Online + Offline) that share the clock.
Then the core would copy this mask onto policy->related_cpus and will
reset policy->cpus to carry only online cpus.

acpi-cpufreq driver wasn't updated with this assumption and so
sometimes when we try to hot[un]plug CPUs at run time, sysfs
directories get corrupted.

This patch fixes acpi-cpufreq driver against this corruption.
Reported-and-tested-by: NMaciej Rutecki <maciej.rutecki@gmail.com>
Tested-by: NBorislav Petkov <bp@suse.de>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

In cpufreq_stats_free_sysfs() we aren't balancing calls to
cpufreq_cpu_get() with cpufreq_cpu_put(). This will never let us have
ref count to policy->kobj as zero.

We will get a hang if somehow cpufreq_driver_unregister() is called.
And that can happen when we compile our driver as module and
insmod/rmmod it.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Acked-by: NAmit Kucheria <amit.kucheria@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

They are defined in coreboot (MSR_PLATFORM) and the other
one is already defined in msr-index.h.

Let's use those.
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Acked-by: NDirk Brandewie <dirk.j.brandewie@intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Use the correct pstate value to calculate the effective frequency.

References: https://bugzilla.redhat.com/show_bug.cgi?id=923942Reported-by: NSatish Balay <balay@fastmail.fm>
Signed-off-by: NDirk Brandewie <dirk.j.brandewie@intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Some VMs seem to try to implement some MSRs but not all the registers
the driver needs.  Check to make sure all the MSR that we need are
available. If any of the required MSRs are not available refuse to
load.

References: https://bugzilla.redhat.com/show_bug.cgi?id=922923Reported-by: NJosh Stone <jistone@redhat.com>
Signed-off-by: NDirk Brandewie <dirk.j.brandewie@intel.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

It seems some VMs support the P state MSRs but return zeros. Fail
gracefully if we are running in this environment.

References: https://bugzilla.redhat.com/show_bug.cgi?id=916833Reported-by: NJosh Boyer <jwboyer@redhat.com>
Signed-off-by: NDirk Brandewie <dirk.j.brandewie@intel.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

If cpufreq_register_driver() fails just free memory that has been
allocated and return. intel_pstate_exit() function is removed since we
are built-in only now there is no reason for a module exit procedure.
Reported-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: NDirk Brandewie <dirk.j.brandewie@intel.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

As uninitialized array members will be initialized to zero, we can
avoid using a for loop by setting a value to it.
Signed-off-by: NEmilio López <emilio@elopez.com.ar>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Acked-By: NMark Langsdorf <mark.langsdorf@calxeda.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Fix a typo in a comment in cpufreq_governor.h.

[rjw: Changelog]
Signed-off-by: NNamhyung Kim <namhyung@kernel.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

In case of error, the function devm_regulator_get() returns
ERR_PTR() and never returns NULL. The NULL test in the return
value check should be replaced with IS_ERR().
Signed-off-by: NWei Yongjun <yongjun_wei@trendmicro.com.cn>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Acked-by: NShawn Guo <shawn.guo@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

When intel_pstate is configured into the kernel it will become the
preferred scaling driver for processors that it supports.  Allow the
user to override this by adding:
   intel_pstate=disable
on the kernel command line.
Signed-off-by: NDirk Brandewie <dirk.j.brandewie@intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Load order is important in order for intel_pstate to take over as the
default scaling driver from acpi-cpufreq.

If both are built-in, acpi-cpufreq uses late_initcall() and
intel_pstate uses device_initcall() so it will be able to register as
the scaling before acpi-cpufreq for the processors supported by
intel_pstate.

If acpi-cpufreq is built as a module then intel_pstate still gets
first option to become the scaling driver.
Signed-off-by: NDirk Brandewie <dirk.j.brandewie@intel.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

There was a dangling #include <mach/id.h> in the cpufreq
file missing from commit
7a4f2609
"ARM: ux500: de-globalize <mach/id.h>"

Causing build regressions when building with cpufreq
support.

Cc: arm@kernel.org
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Fixes 32 bit build.

on i386:
drivers/built-in.o: In function `intel_pstate_timer_func':
intel_pstate.c:(.text+0x4ce97e): undefined reference to `__udivdi3'
drivers/built-in.o: In function `intel_pstate_cpu_init':
intel_pstate.c:(.cpuinit.text+0x974): undefined reference to `__udivdi3'
Reported-by: NRandy Dunlap <rdunlap@infradead.org>
Signed-off-by: NDirk Brandewie <dirk.j.brandewie@intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Fix a couple of typos in comments.
Signed-off-by: NStratos Karafotis <stratosk@semaphore.gr>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Fix some typos in comments.
Signed-off-by: NStratos Karafotis <stratosk@semaphore.gr>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

With the recent changes in cpufreq core, we just need to set mask of all
possible cpus into policy->cpus. Rest would be done by core.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The Marvell Kirkwood SoCs have simple cpufreq support in hardware. The
CPU can either use the a high speed cpu clock, or the slower DDR
clock. Add a driver to swap between these two clock sources.
Signed-off-by: NAndrew Lunn <andrew@lunn.ch>
Acked-by: NJason Cooper <jason@lakedaemon.net>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Add a P-state driver for the Intel Sandy bridge processor. In cpufreq
terminology this driver implements a  scaling driver with an internal
governor.

When built into the the kernel this driver will be the preferred
scaling driver for Sandy bridge processors.

In addition to the interfaces provided by the cpufreq subsystem for
controlling scaling drivers. The user may control the behavior of the
driver via three sysfs files located in
"/sys/devices/system/cpu/intel_pstate".

  max_perf_pct: limits the maximum P state that will be requested by
  the driver stated as a percentage of the avail performance.

  min_perf_pct: limits the minimum P state that will be  requested by
  the driver stated as a percentage of the avail performance.

  no_turbo: limits the driver to selecting P states below the turbo
  frequency range.
Signed-off-by: NDirk Brandewie <dirk.j.brandewie@intel.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The sysfs files for cpufreq_stats are created in cpufreq_stats_create_table()
called from cpufreq_stat_notifier_policy() when a policy is added to
the cpu. cpufreq_stats_create_table() will not be called if the
scaling driver does not export a frequency table to cpufreq.  Use the
same fence on tear down.
Signed-off-by: NDirk Brandewie <dirk.j.brandewie@intel.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Scaling drivers that implement internal governors do not have governor
structures assocaited with them.  Only track the name of the governor
associated with the CPU if the driver does not implement
cpufreq_driver.setpolicy()
Signed-off-by: NDirk Brandewie <dirk.j.brandewie@intel.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Scaling drivers that implement cpufreq_driver.setpolicy() have
internal governors that do not signal changes via
cpufreq_notify_transition() so the frequncy in the policy will almost
certainly be different than the current frequncy.  Only call
cpufreq_out_of_sync() when the underlying driver implements
cpufreq_driver.target()
Signed-off-by: NDirk Brandewie <dirk.j.brandewie@intel.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Scaling drivers that implement the cpufreq_driver.setpolicy() versus
the cpufreq_driver.target() interface do not set policy->cur.

Normally policy->cur is set during the call to cpufreq_driver.target()
when the frequnecy request is made by the governor.

If the scaling driver implements cpufreq_driver.setpolicy() and
cpufreq_driver.get() interfaces use cpufreq_driver.get() to retrieve
the current frequency.
Signed-off-by: NDirk Brandewie <dirk.j.brandewie@intel.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

cpufreq core uses two locks:
- cpufreq_driver_lock: General lock for driver and cpufreq_cpu_data array.
- cpu_policy_rwsemfix locking: per CPU reader-writer semaphore designed to cure
  all cpufreq/hotplug/workqueue/etc related lock issues.

These locks were not used properly and are placed against their principle
(present before their definition) at various places. This patch is an attempt to
fix their use.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

On the lines of macro: lock_policy_rwsem, we can create another macro for
unlock_policy_rwsem. Lets do it.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Because the sibling cpu of any online cpu is identified very early in
cpufreq_add_dev(), below code is never executed. And so can be removed.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

On multi-policy systems there is a single instance of governor for both the
policies (if same governor is chosen for both policies). With the code update
from following patches:

8eeed095 cpufreq: governors: Get rid of dbs_data->enable field
b394058f cpufreq: governors: Reset tunables only for cpufreq_unregister_governor()

We are creating/removing sysfs directory of governor for for every call to
GOV_START and STOP. This would fail for multi-policy system as there is a
per-policy call to START/STOP.

This patch reuses the governor->initialized variable to detect total users of
governor.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

In order to avoid the calculation of up_threshold - down_differential
every time that the frequency must be decreased, we replace the
down_differential tuner with the adj_up_threshold which keeps the
difference across multiple checks.

Update the adj_up_threshold only when the up_theshold is also updated.
Signed-off-by: NStratos Karafotis <stratosk@semaphore.gr>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Macro "CPUFREQ_STATDEVICE_ATTR" is defined local to cpufreq_stats.c file and is
almost a copy of the generic version present in cpufreq.h file. Lets use the
generic version instead.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

policy->cpu or cpus in policy->cpus can't be offline anymore. And so we don't
need to check if they are online or not.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Add an imx6q-cpufreq driver for Freescale i.MX6Q SoC to handle the
hardware specific frequency and voltage scaling requirements.

The driver supports module build and is instantiated by the platform
device/driver mechanism, so that it will not be instantiated on other
platforms, as IMX is built with multiplatform support.
Signed-off-by: NShawn Guo <shawn.guo@linaro.org>
Reviewed-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

"cpufreq" directory in policy->cpu is never created using
sysfs_create_link(), but using kobject_init_and_add(). And so we
shouldn't call sysfs_remove_link() for policy->cpu().  sysfs stuff
for policy->cpu is automatically removed when we call kobject_put()
for dying policy.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Tested-by: NDirk Brandewie <dirk.brandewie@gmail.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>