CPU_FREQ_GOV_SCHEDUTIL gained a dependency on SMP, so now we
get a warning if it gets selected by CPU_FREQ_DEFAULT_GOV_SCHEDUTIL
without SMP:

warning: (CPU_FREQ_DEFAULT_GOV_SCHEDUTIL) selects CPU_FREQ_GOV_SCHEDUTIL which has unmet direct dependencies (CPU_FREQ && SMP)

This adds another dependency to avoid the problem.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Fixes: bf7cdff1 (cpufreq: schedutil: Make it depend on CONFIG_SMP)
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Make the schedutil cpufreq governor depend on CONFIG_SMP, because
the scheduler-provided utilization numbers used by it are only
available with CONFIG_SMP set.

Fixes: 9bdcb44e (cpufreq: schedutil: New governor based on scheduler utilization data)
Reported-by: NSteve Muckle <steve.muckle@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Multiple platforms are using the generic cpufreq-dt driver now, and all
of them are required to create a platform device with name "cpufreq-dt",
in order to get the cpufreq-dt probed.

Many of them do it from platform code, others have special drivers just
to do that.

It would be more sensible to do this at a generic place, where all such
platform can mark their entries.

This patch adds a separate file to get this device created. Currently
the compat list of platforms that we support is empty, and will be
filled in as and when we move platforms to use it.

It always compiles as part of the kernel and so doesn't need a
module-exit operation.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Add a new cpufreq scaling governor, called "schedutil", that uses
scheduler-provided CPU utilization information as input for making
its decisions.

Doing that is possible after commit 34e2c555 (cpufreq: Add
mechanism for registering utilization update callbacks) that
introduced cpufreq_update_util() called by the scheduler on
utilization changes (from CFS) and RT/DL task status updates.
In particular, CPU frequency scaling decisions may be based on
the the utilization data passed to cpufreq_update_util() by CFS.

The new governor is relatively simple.

The frequency selection formula used by it depends on whether or not
the utilization is frequency-invariant.  In the frequency-invariant
case the new CPU frequency is given by

	next_freq = 1.25 * max_freq * util / max

where util and max are the last two arguments of cpufreq_update_util().
In turn, if util is not frequency-invariant, the maximum frequency in
the above formula is replaced with the current frequency of the CPU:

	next_freq = 1.25 * curr_freq * util / max

The coefficient 1.25 corresponds to the frequency tipping point at
(util / max) = 0.8.

All of the computations are carried out in the utilization update
handlers provided by the new governor.  One of those handlers is
used for cpufreq policies shared between multiple CPUs and the other
one is for policies with one CPU only (and therefore it doesn't need
to use any extra synchronization means).

The governor supports fast frequency switching if that is supported
by the cpufreq driver in use and possible for the given policy.
In the fast switching case, all operations of the governor take
place in its utilization update handlers.  If fast switching cannot
be used, the frequency switch operations are carried out with the
help of a work item which only calls __cpufreq_driver_target()
(under a mutex) to trigger a frequency update (to a value already
computed beforehand in one of the utilization update handlers).

Currently, the governor treats all of the RT and DL tasks as
"unknown utilization" and sets the frequency to the allowed
maximum when updated from the RT or DL sched classes.  That
heavy-handed approach should be replaced with something more
subtle and specifically targeted at RT and DL tasks.

The governor shares some tunables management code with the
"ondemand" and "conservative" governors and uses some common
definitions from cpufreq_governor.h, but apart from that it
is stand-alone.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Acked-by: NPeter Zijlstra (Intel) <peterz@infradead.org>

Move abstract code related to struct gov_attr_set to a separate (new)
file so it can be shared with (future) goverernors that won't share
more code with "ondemand" and "conservative".

No intentional functional changes.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>

Commit 0eb463be3436 (cpufreq: governor: Replace timers with utilization
update callbacks) made CPU_FREQ select IRQ_WORK, but that's not
necessary, as it is sufficient for IRQ_WORK to be selected by
CPU_FREQ_GOV_COMMON, so modify the cpufreq Kconfig to that effect.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>

Instead of using a per-CPU deferrable timer for queuing up governor
work items, register a utilization update callback that will be
invoked from the scheduler on utilization changes.

The sampling rate is still the same as what was used for the
deferrable timers and the added irq_work overhead should be offset by
the eliminated timers overhead, so in theory the functional impact of
this patch should not be significant.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Tested-by: NGautham R. Shenoy <ego@linux.vnet.ibm.com>

My previous patch to avoid link errors with the qoriq cpufreq
driver disallowed all of the broken cases, but also prevented
the driver from being built when CONFIG_THERMAL is a module.

This changes the dependency to allow the cpufreq driver to
also be a module in this case, just not built-in.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Fixes: 8ae1702a (cpufreq: qoriq: Register cooling device based on device tree)
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

This driver works on all QorIQ platforms which include
ARM-based cores and PPC-based cores.
Rename it in order to represent better.
Signed-off-by: NTang Yuantian <Yuantian.Tang@freescale.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

SRCU is not necessary to be compiled by default in all cases. For tinification
efforts not compiling SRCU unless necessary is desirable.

The current patch tries to make compiling SRCU optional by introducing a new
Kconfig option CONFIG_SRCU which is selected when any of the components making
use of SRCU are selected.

If we do not select CONFIG_SRCU, srcu.o will not be compiled at all.

   text    data     bss     dec     hex filename
   2007       0       0    2007     7d7 kernel/rcu/srcu.o

Size of arch/powerpc/boot/zImage changes from

   text    data     bss     dec     hex filename
 831552   64180   23944  919676   e087c arch/powerpc/boot/zImage : before
 829504   64180   23952  917636   e0084 arch/powerpc/boot/zImage : after

so the savings are about ~2000 bytes.
Signed-off-by: NPranith Kumar <bobby.prani@gmail.com>
CC: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
CC: Josh Triplett <josh@joshtriplett.org>
CC: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
[ paulmck: resolve conflict due to removal of arch/ia64/kvm/Kconfig. ]

CPUFreq driver's Kconfig entries are added in Kconfig.<arch> files and they are
all included from the main Kconfig file using a menu entry. This creates another
level of (unnecessary) hierarchy within the menuconfig entries.

The problem occurs when there are drivers usable across architectures. Either
their config entry is duplicated in all the supported architectures or is put
into the main Kconfig entry. With the later one, we have menuconfig entries for
drivers at two levels then.

Fix these issues by getting rid of another level of menuconfig hierarchy and
populate all drivers within the main cpufreq menu. To clearly distinguish where
the drivers start from, also add a comment that will appear in menuconfig.
Reported-by: NTang Yuantian <Yuantian.Tang@freescale.com>
Suggested-by: NScott Wood <scottwood@freescale.com>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

This patch adds cpufreq driver for Loongson1B which
is capable of changing the CPU frequency dynamically.
Signed-off-by: NKelvin Cheung <keguang.zhang@gmail.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The intel_pstate driver only supports the performance and the powersave
governors. With the performance governor ensuring the highest possible
performance settings, userspace tools fail to make any lasting changes.
In order to allow userspace tools to make modifications to the settings,
the powersave governor must be in use. This makes having the powersave
governor as the default convenient for systems where the intel_pstate
driver is being employed. Having to enable expert mode in the kernel
configuration is just a headache for such a trivial task.

This patch applies to all kernel versions 2.6.38 or greater after the
migration from CONFIG_EMBEDDED to CONFIG_EXPERT (6a108a14). Most
importantly, this applies to kernel versions 3.9 or greater when the
intel_pstate driver was introduced.
Signed-off-by: NJames Geboski <jgeboski@gmail.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The naming convention of this driver was always under the scanner, people
complained that it should have a more generic name than cpu0, as it manages all
CPUs that are sharing clock lines.

Also, in future it will be modified to support any number of clusters with
separate clock/voltage lines.

Lets rename it to 'cpufreq_dt' from 'cpufreq_cpu0'.
Tested-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

5fbfbcd3 ("cpufreq: cpufreq-cpu0: remove dependency on THERMAL and
REGULATOR") was a little too quick in completely removing the dependency
on the THERMAL driver.

The problem is that while there are inline wrappers to turn the thermal
API calls into empty functions, those do not help if the cpu-thermal
driver is a loadable module and cpufreq-cpu0 is builtin.

Since CONFIG_CPU_THERMAL is a bool option that decides whether the cpu
code is built into the thermal module or not, we have to use a dependency
on the thermal driver itself. However, if CPU_THERMAL is disabled, we
don't need the dependency, hence the strange '!CPU_THERMAL || THERMAL'
construct.

Fixes: 5fbfbcd3 ("cpufreq: cpufreq-cpu0: remove dependency on THERMAL and REGULATOR")
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Tested-by: NViresh Kumar <viresh.kumar@linaro.org>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

cpufreq-cpu0 uses thermal framework to register a cooling device, but doesn't
depend on it as there are dummy calls provided by thermal layer when
CONFIG_THERMAL=n. And when these calls fail, the driver is still usable.

Similar explanation is valid for regulators as well. We do have dummy calls
available for regulator APIs and the driver can work even when those calls
fail.

So, we don't really need to mention thermal and regulators as a dependency for
cpufreq-cpu0 in Kconfig as platforms without support for thermal/regulator can
also use this driver. Remove this dependency.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Enable cpufreq and power kconfig menus on arm64 along with arm cpufreq
drivers. The power menu is needed for OPP support. At least on Calxeda
systems, the same cpufreq driver is used for arm and arm64 based
systems.
Signed-off-by: NRob Herring <rob.herring@calxeda.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NMark Brown <broonie@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Enable cpufreq and power kconfig menus on arm64 along with arm cpufreq
drivers. The power menu is needed for OPP support. At least on Calxeda
systems, the same cpufreq driver is used for arm and arm64 based
systems.
Signed-off-by: NRob Herring <rob.herring@calxeda.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NMark Brown <broonie@linaro.org>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

Add CONFIG_CPU_FREQ_BOOST_SW Kconfig option such that software-managed
boost is enabled only after selecting "EXYNOS Frequency Overclocking -
Software".  It also depends on the thermal subsystem to be compiled in,
which is necessary for disabling boost and cooling down the device when
overheating is detected.

Software-managed boost _MUST_ _NOT_ be enabled without thermal subsystem
with properly defined overheating temperature thresholds.

This option doesn't affect the x86's hardware-driven boost support
in the acpi-cpufreq driver.
Signed-off-by: NLukasz Majewski <l.majewski@samsung.com>
Signed-off-by: NMyungjoo Ham <myungjoo.ham@samsung.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
[rjw: Subject and changelog]
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

PM_OPP is a helper library used by several of the existing cpufreq drivers.
Some of the drivers select this symbol while others depend on it and rely
on the architecture to enable it. Make this behaviour more consistent and
obvious by having all the drivers select the symbol. This will also allow
better build coverage of the affected drivers.
Signed-off-by: NMark Brown <broonie@linaro.org>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

This patch changes the cpufreq-cpu0 driver to consider if
a cpu needs cooling (with cpufreq). In case the cooling is needed,
the cpu0 device tree node needs to be properly configured
with cooling device properties.

In case these properties are present,, the driver will
load a cpufreq cooling device in the system. The cpufreq-cpu0
driver is not interested in determining how the system should
be using the cooling device. The driver is responsible
only of loading the cooling device.

Describing how the cooling device will be used can be
accomplished by setting up a thermal zone that references
and is composed by the cpufreq cooling device.

Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: cpufreq@vger.kernel.org
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: devicetree-discuss@lists.ozlabs.org
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NEduardo Valentin <eduardo.valentin@ti.com>

CONFIG_CPU_FREQ_TABLE will be always enabled when cpufreq framework is used, as
cpufreq core depends on it. So, we don't need this CONFIG option anymore as it
is not configurable. Remove CONFIG_CPU_FREQ_TABLE and update its users.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Many CPUFreq drivers for SMP system (where all cores share same clock lines), do
similar stuff in their ->init() part.

This patch creates a generic routine in cpufreq core which can be used by these
so that we can remove some redundant code.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Kconfig dependecies for ARM SA11xx drivers are incorrect, so fix
them.

[rjw: Changelog]
Signed-off-by: NAlexander Shiyan <shc_work@mail.ru>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

This patch moves cpufreq driver of SPARC architecture to drivers/cpufreq.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

This patch moves cpufreq driver of SUPERH architecture to drivers/cpufreq.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Acked-by: NPaul Mundt <lethal@linux-sh.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

This patch moves cpufreq driver of MIPS architecture to drivers/cpufreq.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Acked-by: NJohn Crispin <blogic@openwrt.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

This patch moves cpufreq driver of IA64 architecture to drivers/cpufreq.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Acked-by: NTony Luck <tony.luck@intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

This patch moves cpufreq driver of AVR32 based at32ap platform to
drivers/cpufreq.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Acked-by: NHans-Christian Egtvedt <egtvedt@samfundet.no>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

As multiplatform build is being adopted by more and more ARM platforms,
initcall function should be used very carefully.  For example, when
GENERIC_CPUFREQ_CPU0 is built in the kernel, cpu0_cpufreq_driver_init()
will be called on all the platforms to initialize cpufreq-cpu0 driver.

To eliminate this undesired the effect, the patch changes cpufreq-cpu0
driver to have it instantiated as a platform_driver.  Then it will only
run on platforms that create the platform_device "cpufreq-cpu0".

Along with the change, it also changes cpu_dev to be &pdev->dev,
so that managed functions can start working, and module build gets
supported too.

The highbank-cpufreq driver is also updated accordingly to adapt the
changes on cpufreq-cpu0.
Signed-off-by: NShawn Guo <shawn.guo@linaro.org>
Reviewed-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>

Since commit 2aacdfff entitled "cpufreq: Move common part from governors
to separate file", whenever the drivers that depend on this new file
(cpufreq_ondemand or cpufreq_conservative) are built as modules, a new
module named cpufreq_governor is created because the Makefile includes
cpufreq_governor.o twice. As drivers/cpufreq/cpufreq_governor.c contains no
MODULE directives, the resulting module has no license specified, which
results in logging of a "module license 'unspecified' taints kernel". In
addition, a number of globals are exported GPL only, and are therefore
not available. This fix establishes a new boolean configuration variable
that forces cpufreq_governor.o to be linked into the kernel whenever
either cpufreq_ondemand or cpufreq_conservative is selected.
Signed-off-by: NLarry Finger <Larry.Finger@lwfinger.net>
Reviewed-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

It adds a generic cpufreq driver for CPU0 frequency management based on
clk, regulator, OPP and device tree support.  It can support both
uniprocessor (UP) and those symmetric multiprocessor (SMP) systems which
share clock and voltage across all CPUs.
Signed-off-by: NShawn Guo <shawn.guo@linaro.org>
Acked-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: NAnilKumar Ch <anilkumar@ti.com>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

Add simple cpufreq driver for Maple-based boards (ppc970fx evaluation
kit and others). Driver is based on a cpufreq driver for 64-bit powermac
boxes with all pmac-dependant features removed and simple cleanup
applied.
Signed-off-by: NDmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

According to discussion of the ARM arch subsystem migration,
ARM cpufreq drivers move to drivers/cpufreq. So this patch
adds Kconfig.arm for ARM like x86 and adds Samsung S5PV210
and EXYNOS4210 cpufreq driver compile in there.
As a note, otherw will be moved.

Cc: Dave Jones <davej@redhat.com>
Signed-off-by: NKukjin Kim <kgene.kim@samsung.com>
Signed-off-by: NDave Jones <davej@redhat.com>

Signed-off-by: NDave Jones <davej@redhat.com>

With dynamic debug having gained the capability to report debug messages
also during the boot process, it offers a far superior interface for
debug messages than the custom cpufreq infrastructure. As a first step,
remove the old cpufreq_debug_printk() function and replace it with a call
to the generic pr_debug() function.

How can dynamic debug be used on cpufreq? You need a kernel which has
CONFIG_DYNAMIC_DEBUG enabled.

To enabled debugging during runtime, mount debugfs and

$ echo -n 'module cpufreq +p' > /sys/kernel/debug/dynamic_debug/control

for debugging the complete "cpufreq" module. To achieve the same goal during
boot, append

	ddebug_query="module cpufreq +p"

as a boot parameter to the kernel of your choice.

For more detailled instructions, please see
Documentation/dynamic-debug-howto.txt
Signed-off-by: NDominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: NDave Jones <davej@redhat.com>

The meaning of CONFIG_EMBEDDED has long since been obsoleted; the option
is used to configure any non-standard kernel with a much larger scope than
only small devices.

This patch renames the option to CONFIG_EXPERT in init/Kconfig and fixes
references to the option throughout the kernel.  A new CONFIG_EMBEDDED
option is added that automatically selects CONFIG_EXPERT when enabled and
can be used in the future to isolate options that should only be
considered for embedded systems (RISC architectures, SLOB, etc).

Calling the option "EXPERT" more accurately represents its intention: only
expert users who understand the impact of the configuration changes they
are making should enable it.
Reviewed-by: NIngo Molnar <mingo@elte.hu>
Acked-by: NDavid Woodhouse <david.woodhouse@intel.com>
Signed-off-by: NDavid Rientjes <rientjes@google.com>
Cc: Greg KH <gregkh@suse.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Robin Holt <holt@sgi.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

It is always "an" if there is a vowel _spoken_ (not written).
So it is:
"an hour" (spoken vowel)
but
"a uniform" (spoken 'j')
Signed-off-by: NFrederik Schwarzer <schwarzerf@gmail.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

Allow use of the powersave cpufreq governor as the default one for EMBEDDED
configs.
Signed-off-by: NAlessandro Guido <alessandro.guido@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NDave Jones <davej@redhat.com>

cpufreq support can't be built as a module. Fix the related configuration
help message.
Signed-off-by: NStefano Brivio <stefano.brivio@polimi.it>
Signed-off-by: NDave Jones <davej@redhat.com>