Add the compatible string for supporting the generic device tree cpufreq-dt
driver on APM's X-Gene 2 SoC.
Signed-off-by: Hoan Tran <hotran@apm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Make intel_pstate update per-logical-CPU limits when the global
settings are changed to ensure that they are always in sync and
users will not see confusing values in per-logical-CPU sysfs
attributes.

This also fixes the problem that setting the "no_turbo" global
attribute to 1 in the "passive" mode (ie. when intel_pstate acts
as a regular cpufreq driver) when scaling_governor is set to
"performance" has no effect.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>

Race conditions are possible if intel_cpufreq_verify_policy()
is executed in parallel with global limits updates from sysfs,
so the invocation of intel_pstate_update_perf_limits() in it
should be carried out under intel_pstate_limits_lock.

Make that happen.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>

Theoretically, intel_pstate_resume() may be executed in parallel
with intel_pstate_set_policy(), if the latter is invoked via
cpufreq_update_policy() as a result of a notification, so use
intel_pstate_limits_lock in there too to avoid race conditions.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>

If intel_pstate works in the passive mode in which it acts as
a regular cpufreq driver and collaborates with generic cpufreq
governors, the PID parameters are not used, so do not expose
them via debugfs in that case.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

s3c64xx_cpufreq_config_regulator is incorrectly annotated
as __init, since the caller is also not init:

WARNING: vmlinux.o(.text+0x92fe1c): Section mismatch in reference from the function s3c64xx_cpufreq_driver_init() to the function .init.text:s3c64xx_cpufreq_config_regulator()

With modern gcc versions, the function gets inline, so we don't
see the warning, this only happens with gcc-4.6 and older.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Since CPU hotplug callbacks are requested for CPUHP_AP_ONLINE_DYN state,
successful callback initialization will result in cpuhp_setup_state()
returning a positive value. Therefore acpi_cpufreq_online being zero
indicates that callbacks have not been installed.

This means that acpi_cpufreq_boost_exit() should only remove them if
acpi_cpufreq_online is positive. Trying to call
cpuhp_remove_state_nocalls(0) will cause a BUG().
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

When ivoked with CPUHP_AP_ONLINE_DYN state __cpuhp_setup_state()
is expected to return positive value which is the hotplug state that
the routine assigns.
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Updated documentation for the support of energy performance hint in
the HWP mode.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
[ rjw: Subject & changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

It is possible to provide hints to the HWP algorithms in the processor
to be more performance centric to more energy centric. These hints are
provided by using HWP energy performance preference (EPP) or energy
performance bias (EPB) settings.

The scope of these settings is per logical processor, which means that
each of the logical processors in the package can be programmed with a
different value.

This change provides cpufreq sysfs interface to provide hint. For each
policy, two additional attributes will be available to check and provide
hint. These attributes will only be present when the intel_pstate driver
is using HWP mode.

These attributes are:
 - energy_performance_available_preferences
 - energy_performance_preference

To get list of supported hints:
$ cat energy_performance_available_preferences
default performance balance_performance balance_power power

The current preference can be read or changed via cpufreq sysfs
attribute "energy_performance_preference". Reading from this attribute
will display current effective setting changed via any method. User can
write any of the valid preference string to this attribute. User can
always restore to power-on default by writing "default".

Implementation
Since these hints can be provided by direct MSR write or using some tools
like x86_energy_perf_policy, the driver internally doesn't maintain any
state. The user operation will result in direct read/write of MSR: 0x774
(HWP_REQUEST_MSR). Also driver use read modify write to update other
fields in this MSR.

Summary of changes:
 - struct cpudata field epp_saved is renamed to epp_powersave, as this
   stores the value to restore once policy is switched from performance
   to powersave to restore original powersave EPP value.
 - A new struct cpudata field epp_saved is used to store the raw MSR
   EPP/EPB value when a CPU goes offline or on suspend and restore on
   online/resume. This ensures that EPP value is restored to correct
   value irrespective of the means used to set.
 - EPP/EPB value ranges are fixed for each preference, which can be
   set for the cpufreq sysfs, so user request is mapped to/from this
   range.
 - New attributes are only added when HWP is present.
 - Since EPP value of 0 is valid the fields are initialized to
   -EINVAL when not valid. The field epp_default is read only once
   after powerup to avoid reading on subsequent CPU online operation
 - New suspend callback to store epp on suspend operation
 - Don't invalidate old epp_saved field on resume and online as now
   we can restore last epp value on suspend and this field can still
   have old EPP value sampled during switch to performance from
   powersave.
 - While here optimized setting of cpu_data->epp_powersave = epp in
   intel_pstate_hwp_set() as this was done in both true and false
   paths.
 - epp/epb set function returns error to caller on failure to pass
   on to user space for display.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

To avoid race conditions from multiple threads, increase the scope
of intel_pstate_limits_lock to include HWP requests also.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
[ rjw: Subject ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Currently the minimal up_threshold is 11, and user may want to
use a smaller minimal up_threshold for performance tuning,
so MIN_FREQUENCY_UP_THRESHOLD could be set to 1 because:

1. Current systems wouldn't be affected as they have already
   a value >= 11.
2. New systems with a default kernel would keep still the default
   value that is >= 11.

Users now have the advantage that they can make their own decisions
and customize the 'trip point' to switch to the max frequency.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=65501Signed-off-by: Chen Yu <yu.c.chen@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Add Knights Mill (KNM) to the list of CPUIDs supported by intel_pstate.
Signed-off-by: Piotr Luc <piotr.luc@intel.com>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

The kernel Bugzilla is used for tracking cpufreq bugs, so document
that.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Len Brown <len.brown@intel.com>

Add the compatible string for supporting the generic cpufreq driver on
the ZTE's zx296718 SoC.
Signed-off-by: Baoyou Xie <baoyou.xie@linaro.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

The online / pre_down callback is invoked on the target CPU since commit
1cf4f629 ("cpu/hotplug: Move online calls to hotplugged cpu") which means
for the hotplug callback we can use rmdsrl() instead of rdmsr_on_cpus().

This leaves us with set_boost() as the only user which still needs to
read/write the MSR on different CPUs. There is no point in doing that
update on all cpus with the read modify write magic via per cpu data. We
simply can issue a function call on all online CPUs which also means that we
need half that many IPIs.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Install the callbacks via the state machine.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

The addition of the generic governor support marked the
intel_pstate_exit_perf_limits as inline(), which fixed a warning,
but it introduced another warning:

drivers/cpufreq/intel_pstate.c: In function ‘intel_pstate_exit_perf_limits’:
drivers/cpufreq/intel_pstate.c:483:1: error: no return statement in function returning non-void [-Werror=return-type]

This changes it back to a 'void' return type, and changes the
corresponding intel_pstate_init_acpi_perf_limits() function to
be inline as well for consistency.

Fixes: 001c76f0 (cpufreq: intel_pstate: Generic governors support)
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

When user has selected performance policy, then set the EPP (Energy
Performance Preference) or EPB (Energy Performance Bias) to maximum
performance mode.

Also when user switch back to powersave, then restore EPP/EPB to last
EPP/EPB value before entering performance mode. If user has not changed
EPP/EPB manually then it will be power on default value.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

This patch rectifies a comment present in sugov_irq_work() function to
follow proper grammar.
Suggested-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Even with round up of limits->min_perf and limits->max_perf, in some
cases resultant performance is 100 MHz less than the desired.

For example when the maximum frequency is 3.50 GHz, setting
scaling_min_frequency to 2.3 GHz always results in 2.2 GHz minimum.

Currently the fixed floating point operation uses 8 bit precision for
calculating limits->min_perf and limits->max_perf. For some operations
in this driver the 14 bit precision is used. Using the 14 bit precision
also for calculating limits->min_perf and limits->max_perf, addresses
this issue.

Introduced fp_ext_toint() equivalent to fp_toint() and int_ext_tofp()
equivalent to int_tofp() with 14 bit precision.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

In some use cases, user wants to enforce a minimum performance limit on
CPUs. But because of simple division the resultant performance is 100 MHz
less than the desired in some cases.

For example when the maximum frequency is 3.50 GHz, setting
scaling_min_frequency to 1.6 GHz always results in 1.5 GHz minimum. With
simple round up, the frequency can be set to 1.6 GHz to minimum in this
case. This round up is already done to max_policy_pct and max_perf, so do
the same for min_policy_pct and min_perf.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

The return value of cpufreq_update_policy() is never used, so make
it void.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>

The return value of acpi_processor_ppc_has_changed() is never used,
so make it void.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>

There are two places in the cpufreq core in which low-level driver
callbacks may be invoked for an inactive cpufreq policy, which isn't
guaranteed to work in general.  Both are due to possible races with
CPU offline.

First, in cpufreq_get(), the policy may become inactive after
the check against policy->cpus in cpufreq_cpu_get() and before
policy->rwsem is acquired, in which case using it going forward may
not be correct.

Second, an analogous situation is possible in cpufreq_update_policy().

Avoid using inactive policies by adding policy_is_inactive() checks
to the code in the above places.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>

There may be reasons to use generic cpufreq governors (eg. schedutil)
on Intel platforms instead of the intel_pstate driver's internal
governor.  However, that currently can only be done by disabling
intel_pstate altogether and using the acpi-cpufreq driver instead
of it, which is subject to limitations.

First of all, acpi-cpufreq only works on systems where the _PSS
object is present in the ACPI tables for all logical CPUs.  Second,
on those systems acpi-cpufreq will only use frequencies listed by
_PSS which may be suboptimal.  In particular, by convention, the
whole turbo range is represented in _PSS as a single P-state and
the frequency assigned to it is greater by 1 MHz than the greatest
non-turbo frequency listed by _PSS.  That may confuse governors to
use turbo frequencies less frequently which may lead to suboptimal
performance.

For this reason, make it possible to use the intel_pstate driver
with generic cpufreq governors as a "normal" cpufreq driver.  That
mode is enforced by adding intel_pstate=passive to the kernel
command line and cannot be disabled at run time.  In that mode,
intel_pstate provides a cpufreq driver interface including
the ->target() and ->fast_switch() callbacks and is listed in
scaling_driver as "intel_cpufreq".
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Doug Smythies <dsmythies@telus.net>

Currently, intel_pstate is unable to control P-states on my
IvyBridge-based Acer Aspire S5, because they are controlled by SMM
on that machine by default and it is necessary to request OS control
of P-states from it via the SMI Command register exposed in the ACPI
FADT.  intel_pstate doesn't do that now, but acpi-cpufreq and other
cpufreq drivers for x86 platforms do.

Address this problem by making intel_pstate use the ACPI-defined
mechanism as well.  However, intel_pstate is not modular and it
doesn't need the module refcount tricks played by
acpi_processor_notify_smm(), so export the core of this function
to it as acpi_processor_pstate_control() and make it call that.
[The changes in processor_perflib.c related to this should not
make any functional difference for the acpi_processor_notify_smm()
users].

To be safe, only call acpi_processor_notify_smm() from intel_pstate
if ACPI _PPC support is enabled in it.
Suggested-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>

Add the compatible strings for supporting the generic cpufreq driver on
the Renesas RZ/G1M (r8a7743) and RZ/G1E (r8a7745) SoCs.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

With preemption turned on we can read incorrect throttling state
while being switched to CPU on a different chip.

 BUG: using smp_processor_id() in preemptible [00000000] code: cat/7343
 caller is .powernv_cpufreq_throttle_check+0x2c/0x710
 CPU: 13 PID: 7343 Comm: cat Not tainted 4.8.0-rc5-dirty #1
 Call Trace:
 [c0000007d25b75b0] [c000000000971378] .dump_stack+0xe4/0x150 (unreliable)
 [c0000007d25b7640] [c0000000005162e4] .check_preemption_disabled+0x134/0x150
 [c0000007d25b76e0] [c0000000007b63ac] .powernv_cpufreq_throttle_check+0x2c/0x710
 [c0000007d25b7790] [c0000000007b6d18] .powernv_cpufreq_target_index+0x288/0x360
 [c0000007d25b7870] [c0000000007acee4] .__cpufreq_driver_target+0x394/0x8c0
 [c0000007d25b7920] [c0000000007b22ac] .cpufreq_set+0x7c/0xd0
 [c0000007d25b79b0] [c0000000007adf50] .store_scaling_setspeed+0x80/0xc0
 [c0000007d25b7a40] [c0000000007ae270] .store+0xa0/0x100
 [c0000007d25b7ae0] [c0000000003566e8] .sysfs_kf_write+0x88/0xb0
 [c0000007d25b7b70] [c0000000003553b8] .kernfs_fop_write+0x178/0x260
 [c0000007d25b7c10] [c0000000002ac3cc] .__vfs_write+0x3c/0x1c0
 [c0000007d25b7cf0] [c0000000002ad584] .vfs_write+0xc4/0x230
 [c0000007d25b7d90] [c0000000002aeef8] .SyS_write+0x58/0x100
 [c0000007d25b7e30] [c00000000000bfec] system_call+0x38/0xfc

Fixes: 09a972d1 (cpufreq: powernv: Report cpu frequency throttling)
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Denis Kirjanov <kda@linux-powerpc.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Execute the irq-work specific initialization/exit code only when the
fast path isn't available.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

If slow path frequency changes are conducted in a SCHED_OTHER context
then they may be delayed for some amount of time, including
indefinitely, when real time or deadline activity is taking place.

Move the slow path to a real time kernel thread. In the future the
thread should be made SCHED_DEADLINE. The RT priority is arbitrarily set
to 50 for now.

Hackbench results on ARM Exynos, dual core A15 platform for 10
iterations:

$ hackbench -s 100 -l 100 -g 10 -f 20

Before			After
---------------------------------
1.808			1.603
1.847			1.251
2.229			1.590
1.952			1.600
1.947			1.257
1.925			1.627
2.694			1.620
1.258			1.621
1.919			1.632
1.250			1.240

Average:

1.8829			1.5041

Based on initial work by Steve Muckle.
Signed-off-by: Steve Muckle <smuckle.linux@gmail.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

The fast_switch_enabled flag will be used by both sugov_policy_alloc()
and sugov_policy_free() with a later patch.

Prepare for that by moving the calls to enable and disable it to the
beginning of sugov_init() and end of sugov_exit().
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Switch to the more common practice of writing labels.
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

The original comment about the frequency increase to maximum is wrong.

Both increase and decrease happen at steps.
Signed-off-by: Stratos Karafotis <stratosk@semaphore.gr>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Conservative governor changes the CPU frequency in steps.
That means that if a CPU runs at max frequency, it will need several
sampling periods to return to min frequency when the workload
is finished.

If the update function that calculates the load and target frequency
is deferred, the governor might need even more time to decrease the
frequency.

This may have impact to power consumption and after all conservative
should decrease the frequency if there is no workload at every sampling
rate.

To resolve the above issue calculate the number of sampling periods
that the update is deferred. Considering that for each sampling period
conservative should drop the frequency by a freq_step because the
CPU was idle apply the proper subtraction to requested frequency.

Below, the kernel trace with and without this patch. First an
intensive workload is applied on a specific CPU. Then the workload
is removed and the CPU goes to idle.

WITHOUT

     <idle>-0     [007] dN..   620.329153: cpu_idle: state=4294967295 cpu_id=7
kworker/7:2-556   [007] ....   620.350857: cpu_frequency: state=1700000 cpu_id=7
kworker/7:2-556   [007] ....   620.370856: cpu_frequency: state=1900000 cpu_id=7
kworker/7:2-556   [007] ....   620.390854: cpu_frequency: state=2100000 cpu_id=7
kworker/7:2-556   [007] ....   620.411853: cpu_frequency: state=2200000 cpu_id=7
kworker/7:2-556   [007] ....   620.432854: cpu_frequency: state=2400000 cpu_id=7
kworker/7:2-556   [007] ....   620.453854: cpu_frequency: state=2600000 cpu_id=7
kworker/7:2-556   [007] ....   620.494856: cpu_frequency: state=2900000 cpu_id=7
kworker/7:2-556   [007] ....   620.515856: cpu_frequency: state=3100000 cpu_id=7
kworker/7:2-556   [007] ....   620.536858: cpu_frequency: state=3300000 cpu_id=7
kworker/7:2-556   [007] ....   620.557857: cpu_frequency: state=3401000 cpu_id=7
     <idle>-0     [007] d...   669.591363: cpu_idle: state=4 cpu_id=7
     <idle>-0     [007] d...   669.591939: cpu_idle: state=4294967295 cpu_id=7
     <idle>-0     [007] d...   669.591980: cpu_idle: state=4 cpu_id=7
     <idle>-0     [007] dN..   669.591989: cpu_idle: state=4294967295 cpu_id=7
...
     <idle>-0     [007] d...   670.201224: cpu_idle: state=4 cpu_id=7
     <idle>-0     [007] d...   670.221975: cpu_idle: state=4294967295 cpu_id=7
kworker/7:2-556   [007] ....   670.222016: cpu_frequency: state=3300000 cpu_id=7
     <idle>-0     [007] d...   670.222026: cpu_idle: state=4 cpu_id=7
     <idle>-0     [007] d...   670.234964: cpu_idle: state=4294967295 cpu_id=7
...
     <idle>-0     [007] d...   670.801251: cpu_idle: state=4 cpu_id=7
     <idle>-0     [007] d...   671.236046: cpu_idle: state=4294967295 cpu_id=7
kworker/7:2-556   [007] ....   671.236073: cpu_frequency: state=3100000 cpu_id=7
     <idle>-0     [007] d...   671.236112: cpu_idle: state=4 cpu_id=7
     <idle>-0     [007] d...   671.393437: cpu_idle: state=4294967295 cpu_id=7
...
     <idle>-0     [007] d...   671.401277: cpu_idle: state=4 cpu_id=7
     <idle>-0     [007] d...   671.404083: cpu_idle: state=4294967295 cpu_id=7
kworker/7:2-556   [007] ....   671.404111: cpu_frequency: state=2900000 cpu_id=7
     <idle>-0     [007] d...   671.404125: cpu_idle: state=4 cpu_id=7
     <idle>-0     [007] d...   671.404974: cpu_idle: state=4294967295 cpu_id=7
...
     <idle>-0     [007] d...   671.501180: cpu_idle: state=4 cpu_id=7
     <idle>-0     [007] d...   671.995414: cpu_idle: state=4294967295 cpu_id=7
kworker/7:2-556   [007] ....   671.995459: cpu_frequency: state=2800000 cpu_id=7
     <idle>-0     [007] d...   671.995469: cpu_idle: state=4 cpu_id=7
     <idle>-0     [007] d...   671.996287: cpu_idle: state=4294967295 cpu_id=7
...
     <idle>-0     [007] d...   672.001305: cpu_idle: state=4 cpu_id=7
     <idle>-0     [007] d...   672.078374: cpu_idle: state=4294967295 cpu_id=7
kworker/7:2-556   [007] ....   672.078410: cpu_frequency: state=2600000 cpu_id=7
     <idle>-0     [007] d...   672.078419: cpu_idle: state=4 cpu_id=7
     <idle>-0     [007] d...   672.158020: cpu_idle: state=4294967295 cpu_id=7
kworker/7:2-556   [007] ....   672.158040: cpu_frequency: state=2400000 cpu_id=7
     <idle>-0     [007] d...   672.158044: cpu_idle: state=4 cpu_id=7
     <idle>-0     [007] d...   672.160038: cpu_idle: state=4294967295 cpu_id=7
...
     <idle>-0     [007] d...   672.234557: cpu_idle: state=4 cpu_id=7
     <idle>-0     [007] d...   672.237121: cpu_idle: state=4294967295 cpu_id=7
kworker/7:2-556   [007] ....   672.237174: cpu_frequency: state=2100000 cpu_id=7
     <idle>-0     [007] d...   672.237186: cpu_idle: state=4 cpu_id=7
     <idle>-0     [007] d...   672.237778: cpu_idle: state=4294967295 cpu_id=7
...
     <idle>-0     [007] d...   672.267902: cpu_idle: state=4 cpu_id=7
     <idle>-0     [007] d...   672.269860: cpu_idle: state=4294967295 cpu_id=7
kworker/7:2-556   [007] ....   672.269906: cpu_frequency: state=1900000 cpu_id=7
     <idle>-0     [007] d...   672.269914: cpu_idle: state=4 cpu_id=7
     <idle>-0     [007] d...   672.271902: cpu_idle: state=4294967295 cpu_id=7
...
     <idle>-0     [007] d...   672.751342: cpu_idle: state=4 cpu_id=7
     <idle>-0     [007] d...   672.823056: cpu_idle: state=4294967295 cpu_id=7
kworker/7:2-556   [007] ....   672.823095: cpu_frequency: state=1600000 cpu_id=7

WITH

     <idle>-0     [007] dN..  4380.928009: cpu_idle: state=4294967295 cpu_id=7
kworker/7:2-399   [007] ....  4380.949767: cpu_frequency: state=2000000 cpu_id=7
kworker/7:2-399   [007] ....  4380.969765: cpu_frequency: state=2200000 cpu_id=7
kworker/7:2-399   [007] ....  4381.009766: cpu_frequency: state=2500000 cpu_id=7
kworker/7:2-399   [007] ....  4381.029767: cpu_frequency: state=2600000 cpu_id=7
kworker/7:2-399   [007] ....  4381.049769: cpu_frequency: state=2800000 cpu_id=7
kworker/7:2-399   [007] ....  4381.069769: cpu_frequency: state=3000000 cpu_id=7
kworker/7:2-399   [007] ....  4381.089771: cpu_frequency: state=3100000 cpu_id=7
kworker/7:2-399   [007] ....  4381.109772: cpu_frequency: state=3400000 cpu_id=7
kworker/7:2-399   [007] ....  4381.129773: cpu_frequency: state=3401000 cpu_id=7
     <idle>-0     [007] d...  4428.226159: cpu_idle: state=1 cpu_id=7
     <idle>-0     [007] d...  4428.226176: cpu_idle: state=4294967295 cpu_id=7
     <idle>-0     [007] d...  4428.226181: cpu_idle: state=4 cpu_id=7
     <idle>-0     [007] d...  4428.227177: cpu_idle: state=4294967295 cpu_id=7
...
     <idle>-0     [007] d...  4428.551640: cpu_idle: state=4 cpu_id=7
     <idle>-0     [007] d...  4428.649239: cpu_idle: state=4294967295 cpu_id=7
kworker/7:2-399   [007] ....  4428.649268: cpu_frequency: state=2800000 cpu_id=7
     <idle>-0     [007] d...  4428.649278: cpu_idle: state=4 cpu_id=7
     <idle>-0     [007] d...  4428.689856: cpu_idle: state=4294967295 cpu_id=7
...
     <idle>-0     [007] d...  4428.799542: cpu_idle: state=4 cpu_id=7
     <idle>-0     [007] d...  4428.801683: cpu_idle: state=4294967295 cpu_id=7
kworker/7:2-399   [007] ....  4428.801748: cpu_frequency: state=1700000 cpu_id=7
     <idle>-0     [007] d...  4428.801761: cpu_idle: state=4 cpu_id=7
     <idle>-0     [007] d...  4428.806545: cpu_idle: state=4294967295 cpu_id=7
...
     <idle>-0     [007] d...  4429.051880: cpu_idle: state=4 cpu_id=7
     <idle>-0     [007] d...  4429.086240: cpu_idle: state=4294967295 cpu_id=7
kworker/7:2-399   [007] ....  4429.086293: cpu_frequency: state=1600000 cpu_id=7

Without the patch the CPU dropped to min frequency after 3.2s
With the patch applied the CPU dropped to min frequency after 0.86s
Signed-off-by: Stratos Karafotis <stratosk@semaphore.gr>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

What's returned from this function is the delta by which the frequency
must be increased or decreased and not the final frequency that should
be selected.

Name it properly to match its purpose. Also update the variables used to
store that value.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

lpstate_idx remains uninitialized in the case when elapsed_time
is greater than MAX_RAMP_DOWN_TIME.  At the end of rampdown the
global pstate should be equal to the local pstate.

Fixes: 20b15b76 (cpufreq: powernv: Use PMCR to verify global and localpstate)
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Akshay Adiga <akshay.adiga@linux.vnet.ibm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Use get_target_pstate_use_cpu_load() to calculate target P-State for
devices, with the preferred power management profile in ACPI FADT
set to PM_MOBILE.

This may help in resolving some thermal issues caused by low sustained
cpu bound workloads. The current algorithm tend to over provision in this
case as it doesn't look at the CPU busyness.

Also included the fix from Arnd Bergmann <arnd@arndb.de> to solve compile
issue, when CONFIG_ACPI is not defined.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>