The cpb sysfs attribute is only exposed by the ACPI cpufreq driver
after a runtime check.  For this purpose, the driver keeps a NULL
placeholder in its table of sysfs attributes and replaces the NULL
with a pointer to an attribute structure if it decides to expose
cpb.

That is confusing, so make the driver set the pointer to the cpb
attribute structure upfront and replace it with NULL if the
attribute should not be exposed instead.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>

After commit 8cfcfd39 (acpi-cpufreq: Fix an ACPI perf unregister
issue) we store both a pointer to per-CPU data of the first policy
CPU and the number of that CPU which are redundant.

Since the CPU number has to be stored anyway for the unregistration,
the pointer to the CPU's per-CPU data may be dropped and we can
access the data in question via per_cpu_ptr().
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>

acpi_processor_unregister_performance() actually doesn't use its
first argument, so drop it and update the callers accordingly.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>

As policy->cpu may not be same in acpi_cpufreq_cpu_init() and
acpi_cpufreq_cpu_exit(). There is a risk that we use different CPU
to un/register ACPI performance. So acpi_processor_unregister_performance()
may not be able to do the cleanup work. That causes a memory leak. And
if there will be another acpi_processor_register_performance() call,
it may also fail thanks to the internal check of pr->performace.

So add a new struct acpi_cpufreq_data field, acpi_perf_cpu, to fix
this issue.
Signed-off-by: NPan Xinhui <xinhuix.pan@intel.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
[ rjw: Changelog ]
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Drivers can store their internal per-policy information in
policy->driver_data, lets use it.

we have benefits after this replacing.
1) memory saving.
2) policy is shared by several cpus, per_cpu seems not correct. using
*driver_data* is more reasonable.
3) fix a memory leak in acpi_cpufreq_cpu_exit. as policy->cpu might
change during cpu hotplug. So sometimes we cant't free *data*, use
*driver_data* to fix it.
4) fix a zero return value of get_cur_freq_on_cpu. Only per_cpu of
policy->cpu is set to *data*, if we try to get cpufreq on other cpus, we
get zero instead of correct values. Use *driver_data* to fix it.
Signed-off-by: NPan Xinhui <xinhuix.pan@intel.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The former duplicate the functionalities of the latter but are
neither documented nor arch-independent.
Signed-off-by: NBartosz Golaszewski <bgolaszewski@baylibre.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Acked-by: NRafael J. Wysocki <rjw@rjwysocki.net>
Cc: Benoit Cousson <bcousson@baylibre.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Jean Delvare <jdelvare@suse.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Drokin <oleg.drokin@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1432645896-12588-7-git-send-email-bgolaszewski@baylibre.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

The cpufreq core now supports the cpufreq_for_each_entry and
cpufreq_for_each_valid_entry macros helpers for iteration over the
cpufreq_frequency_table, so use them.

It should have no functional changes.
Signed-off-by: NStratos Karafotis <stratosk@semaphore.gr>
Acked-by: NLad, Prabhakar <prabhakar.csengg@gmail.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Few drivers are using kmalloc() to allocate memory for frequency
tables and since we will have an additional field '.flags' in
'struct cpufreq_frequency_table', these might become unstable.
Better get these fixed by replacing kmalloc() by kzalloc() instead.

Along with that we also remove use of .driver_data from SPEAr driver
as it doesn't use it at all. Also, writing zero to .driver_data is not
required for powernow-k8 as it is already zero.
Reported-and-reviewed-by: NGautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Subsystems that want to register CPU hotplug callbacks, as well as perform
initialization for the CPUs that are already online, often do it as shown
below:

	get_online_cpus();

	for_each_online_cpu(cpu)
		init_cpu(cpu);

	register_cpu_notifier(&foobar_cpu_notifier);

	put_online_cpus();

This is wrong, since it is prone to ABBA deadlocks involving the
cpu_add_remove_lock and the cpu_hotplug.lock (when running concurrently
with CPU hotplug operations).

Instead, the correct and race-free way of performing the callback
registration is:

	cpu_notifier_register_begin();

	for_each_online_cpu(cpu)
		init_cpu(cpu);

	/* Note the use of the double underscored version of the API */
	__register_cpu_notifier(&foobar_cpu_notifier);

	cpu_notifier_register_done();

Fix the acpi-cpufreq code by using this latter form of callback registration.

Cc: Ingo Molnar <mingo@kernel.org>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NSrivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

freq table is not per CPU but per policy, so it makes more sense to
keep it within struct cpufreq_policy instead of a per-cpu variable.

This patch does it. Over that, there is no need to set policy->freq_table
to NULL in ->exit(), as policy structure is going to be freed soon.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

If cpufreq_register_driver() fails we would free the acpi driver
related structures but not free the ones allocated
by acpi_cpufreq_boost_init() function. This meant that as
the driver error-ed out and a CPU online/offline event came
we would crash and burn as one of the CPU notifiers would point
to garbage.

Fixes: cfc9c8ed (acpi-cpufreq: Adjust the code to use the common boost attribute)
Acked-by: NLukasz Majewski <l.majewski@samsung.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Modify acpi-cpufreq's hardware-based boost solution to work with the
common cpufreq boost framework.
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>

Most of the drivers do following in their ->target_index() routines:

	struct cpufreq_freqs freqs;
	freqs.old = old freq...
	freqs.new = new freq...

	cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);

	/* Change rate here */

	cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);

This is replicated over all cpufreq drivers today and there doesn't exists a
good enough reason why this shouldn't be moved to cpufreq core instead.

There are few special cases though, like exynos5440, which doesn't do everything
on the call to ->target_index() routine and call some kind of bottom halves for
doing this work, work/tasklet/etc..

They may continue doing notification from their own code as flag:
CPUFREQ_ASYNC_NOTIFICATION is already set for them.

All drivers are also modified in this patch to avoid breaking 'git bisect', as
double notification would happen otherwise.
Acked-by: NHans-Christian Egtvedt <egtvedt@samfundet.no>
Acked-by: NJesper Nilsson <jesper.nilsson@axis.com>
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Acked-by: NRussell King <linux@arm.linux.org.uk>
Acked-by: NStephen Warren <swarren@nvidia.com>
Tested-by: NAndrew Lunn <andrew@lunn.ch>
Tested-by: NNicolas Pitre <nicolas.pitre@linaro.org>
Reviewed-by: NLan Tianyu <tianyu.lan@intel.com>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Currently, the prototype of cpufreq_drivers target routines is:

int target(struct cpufreq_policy *policy, unsigned int target_freq,
		unsigned int relation);

And most of the drivers call cpufreq_frequency_table_target() to get a valid
index of their frequency table which is closest to the target_freq. And they
don't use target_freq and relation after that.

So, it makes sense to just do this work in cpufreq core before calling
cpufreq_frequency_table_target() and simply pass index instead. But this can be
done only with drivers which expose their frequency table with cpufreq core. For
others we need to stick with the old prototype of target() until those drivers
are converted to expose frequency tables.

This patch implements the new light weight prototype for target_index() routine.
It looks like this:

int target_index(struct cpufreq_policy *policy, unsigned int index);

CPUFreq core will call cpufreq_frequency_table_target() before calling this
routine and pass index to it. Because CPUFreq core now requires to call routines
present in freq_table.c CONFIG_CPU_FREQ_TABLE must be enabled all the time.

This also marks target() interface as deprecated. So, that new drivers avoid
using it. And Documentation is updated accordingly.

It also converts existing .target() to newly defined light weight
.target_index() routine for many driver.
Acked-by: NHans-Christian Egtvedt <egtvedt@samfundet.no>
Acked-by: NJesper Nilsson <jesper.nilsson@axis.com>
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Acked-by: NRussell King <linux@arm.linux.org.uk>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Tested-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rjw@rjwysocki.net>

Make acpi_cpufreq_init() return error codes when the driver cannot be
registered so that the module doesn't stay useless in memory and so
that acpi_cpufreq_exit() doesn't attempt to unregister things that
have never been registered when the module is unloaded.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>

policy->cur is now set by cpufreq core when cpufreq_driver->get() is defined and
so drivers aren't required to set it. When space_id is ACPI_ADR_SPACE_SYSTEM_IO
for acpi cpufreq driver it doesn't set ->get to a valid function pointer and so
policy->cur is required to be set by driver.

This is already followed in acpi-cpufreq driver. This patch adds a comment
describing why we need to set policy->cur from driver.
Suggested-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Many common initializations of struct policy are moved to core now and hence
this driver doesn't need to do it. This patch removes such code.

Most recent of those changes is to call ->get() in the core after calling
->init().
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Most of the CPUFreq drivers do similar things in .exit() and .verify() routines
and .attr. So its better if we have generic routines for them which can be used
by cpufreq drivers then.

This patch uses the generic verify routine in the ACPI driver.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Lets use cpufreq_table_validate_and_show() instead of calling
cpufreq_frequency_table_cpuinfo() and cpufreq_frequency_table_get_attr().
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

If the hw supports intel_pstate and acpi_cpufreq, intel_pstate will
get loaded first.

acpi_cpufreq_init() will call acpi_cpufreq_early_init()
and that will allocate perf data and init those perf data in ACPI core,
(that will cover all CPUs). But later it will free them as
cpufreq_register_driver(acpi_cpufreq) will fail as intel_pstate is
already registered

Use cpufreq_get_current_driver() to check if we can skip the
acpi_cpufreq loading.
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Standardise the defintion of the cpb (Core Performance Boost)
attribute in the acpi-cpufreq driver via the cpufreq_freq_attr_rw
macro.

[rjw: Subject and changelog]
Signed-off-by: NLan Tianyu <tianyu.lan@intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

We don't need to set .owner = THIS_MODULE any more in cpufreq drivers
as this field isn't used any more by the cpufreq core.

This patch removes it and updates all dependent drivers accordingly.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Chapter 14 of Documentation/CodingStyle says:

The preferred form for passing a size of a struct is the following:

	p = kmalloc(sizeof(*p), ...);

The alternative form where struct name is spelled out hurts
readability and introduces an opportunity for a bug when the pointer
variable type is changed but the corresponding sizeof that is passed
to a memory allocator is not.

This wasn't followed consistently in drivers/cpufreq, let's make it
more consistent by always following this rule.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The target frequency calculation method in the ondemand governor has
changed and it is now independent of the measured average frequency.
Consequently, the APERF/MPERF support in cpufreq is not used any
more, so drop it.

[rjw: Changelog]
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>

Commits fcf80582 (cpufreq: Simplify cpufreq_add_dev()) and aa77a527
(cpufreq: acpi-cpufreq: Don't set policy->related_cpus from .init())
changed the contents of the "related_cpus" sysfs attribute on systems
where acpi-cpufreq is used and user space can't get the list of CPUs
which are in the same hardware coordination CPU domain (provided by
the ACPI AML method _PSD) via "related_cpus" any more.

To make up for that loss add a new sysfs attribute "freqdomian_cpus"
for the acpi-cpufreq driver which exposes the list of CPUs in the
same domain regardless of whether it is coordinated by hardware or
software.

[rjw: Changelog, documentation]
References: https://bugzilla.kernel.org/show_bug.cgi?id=58761Reported-by: NJean-Philippe Halimi <jean-philippe.halimi@exascale-computing.eu>
Signed-off-by: NLan Tianyu <tianyu.lan@intel.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

PRECHANGE and POSTCHANGE notifiers must be called in groups, i.e either both
should be called or both shouldn't be.

In case we have started PRECHANGE notifier and found an error, we
must call POSTCHANGE notifier with freqs.new = freqs.old to
guarantee that the sequence of calling notifiers is complete.

This patch fixes it.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

After commit ac212b69 (ACPI / processor: Use common hotplug
infrastructure) the acpi-cpufreq module is not loaded automatically
by udev which fails to match it against the x86cpu modalias.  Still,
it can be matched against ACPI processor device IDs, which even
makes more sense, because it depends on the ACPI processor driver
that uses those device IDs to bind to processor devices.

For this reason, add ACPI processor device IDs to acpi-cpufreq.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>

Commit 4b31e774 (Always set P-state on initialization) fixed bug
#4634 and caused the driver to always set the target P-State at
least once since the initial P-State may not be the desired one.
Commit 5a1c0228 (cpufreq: Avoid calling cpufreq driver's target()
routine if target_freq == policy->cur) caused a regression in
this behavior.

This fixes the regression by setting policy->cur based on the CPU's
target frequency rather than the CPU's current reported frequency
(which may be different).  This means that the P-State will be set
initially if the CPU's target frequency is different from the
governor's target frequency.

This fixes an issue where setting the default governor to
performance wouldn't correctly enable turbo mode on all cores.
Signed-off-by: NRoss Lagerwall <rosslagerwall@gmail.com>
Reviewed-by: NLen Brown <len.brown@intel.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Cc: 3.8+ <stable@vger.kernel.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The "index" field of struct cpufreq_frequency_table was never an
index and isn't used at all by the cpufreq core.  It only is useful
for cpufreq drivers for their internal purposes.

Many people nowadays blindly set it in ascending order with the
assumption that the core will use it, which is a mistake.

Rename it to "driver_data" as that's what its purpose is. All of its
users are updated accordingly.

[rjw: Changelog]
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Acked-by: NSimon Horman <horms+renesas@verge.net.au>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

When we don't have any file in cpu/cpufreq directory we shouldn't
create it. Specially with the introduction of per-policy governor
instance patchset, even governors are moved to
cpu/cpu*/cpufreq/governor-name directory and so this directory is
just not required.

Lets have it only when required.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

policy->cpus contains all online cpus that have single shared clock line. And
their frequencies are always updated together.

Many SMP system's cpufreq drivers take care of this in individual drivers but
the best place for this code is in cpufreq core.

This patch modifies cpufreq_notify_transition() to notify frequency change for
all cpus in policy->cpus and hence updates all users of this API.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Acked-by: NStephen Warren <swarren@nvidia.com>
Tested-by: NStephen Warren <swarren@nvidia.com>
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>

Implement a generic helper function policy_is_shared() to replace the
current dbs_sw_coordinated_cpus() at cpufreq level, so that it can be
used by code other than cpufreq governors.
Suggested-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NFabio Baltieri <fabio.baltieri@linaro.org>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

de3ed81d ("[CPUFREQ] Change link order of x86 cpufreq modules")
changed cpufreq drivers link order so that powernow-k8 gets loaded first
due to earlier K8s having BIOS bugs.

However, now that acpi-cpufreq supports both AMD and Intel CPUs with HW
P-states, we want to load it first, so that cases where acpi-cpufreq and
powernow-k8 are both built-in and powernow-k8 initializing first, can be
addressed.

So, make sure that even if acpi-cpufreq gets loaded first, it errors out
on K8s and powernow-k8 can be loaded then successfully.
Signed-off-by: NMatthew Garrett <mjg59@srcf.ucam.org>
References: http://lkml.kernel.org/r/20130118162347.GA31499@srcf.ucam.orgSigned-off-by: NBorislav Petkov <bp@suse.de>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The acpi core will call request_module("acpi-cpufreq") on subsystem init,
but this will fail if the module isn't available at that stage of boot.
Add some module aliases to ensure that udev can load the module on Intel
and AMD systems with the appropriate feature bits - I /think/ that this
will also work on VIA systems, but haven't verified that.

References: http://lkml.kernel.org/r/1448223.sdUJnNSRz4@vostro.rjw.lanSigned-off-by: NMatthew Garrett <matthew.garrett@nebula.com>
Tested-by: NLeonid Isaev <lisaev@umail.iu.edu>
Acked-by: NBorislav Petkov <bp@suse.de>
Cc: 3.7+ <stable@vger.kernel.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The powernow-k8 driver supported a sysfs knob called "cpb", which was
instantiated per CPU, but actually acted globally for the whole
system. To keep some compatibility with this feature, we re-introduce
this behavior here, but:
a) only enable it on AMD CPUs and
b) protect it with a Kconfig switch

I'd like to consider this feature obsolete. Lets keep it around for
some kernel versions and then phase it out.
Signed-off-by: NAndre Przywara <andre.przywara@amd.com>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

One feature present in powernow-k8 that isn't present in acpi-cpufreq
is support for enabling or disabling AMD's core performance boost
technology. This patch adds support to acpi-cpufreq, but also
includes support for Intel's dynamic acceleration.

The original boost disabling sysfs file was per CPU, but acted
globally. Also the naming (cpb) was at least not intuitive.
So lets introduce a single file simply called "boost", which sits
once in /sys/devices/system/cpu/cpufreq.
This should be the only way of using this feature, so add
documentation about the rationale and the usage.

A following patch will re-introduce the cpb knob for compatibility
reasons on AMD CPUs.

Per-CPU boost switching is possible, but not trivial and is thus
postponed to a later patch series.
Signed-off-by: NAndre Przywara <andre.przywara@amd.com>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

To workaround some Windows specific behavior, the ACPI _PSD table
on AMD desktop boards advertises all cores as dependent, meaning
that they all can only use the same P-state. acpi-cpufreq strictly
obeys this description, instantiating one CPU only and symlinking
the others. But the hardware can have distinct frequencies for each
core and powernow-k8 did it that way.
So, in order to use the hardware to its full potential and keep the
original powernow-k8 behavior, lets override the _PSD table setting
on AMD hardware.
We use the siblings table, as it matches the current hardware
behavior.
Signed-off-by: NAndre Przywara <andre.przywara@amd.com>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

The programming model for P-states on modern AMD CPUs is very similar to
that of Intel and VIA. It makes sense to consolidate this support into one
driver rather than duplicating functionality between two of them. This
patch adds support for AMDs with hardware P-state control to acpi-cpufreq.
Signed-off-by: NMatthew Garrett <mjg@redhat.com>
Signed-off-by: NAndre Przywara <andre.przywara@amd.com>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

acpi-cpufreq checks each CPU for aperf/mperf support, but only sets a
global flag. This will cause errors if some CPUs in the system don't
support the feature. Check boot_cpu_has() instead in order to make sure
that all CPUs support it.
Signed-off-by: NMatthew Garrett <mjg@redhat.com>
Signed-off-by: NDave Jones <davej@redhat.com>