intel_pstate_set_policy() is invoked by the cpufreq core during
driver initialization, on changes of policy attributes (minimim and
maximum frequency, for example) via sysfs and via CPU notifications
from the platform firmware.  On some platforms the latter may occur
relatively often.

Commit bb6ab52f (intel_pstate: Do not set utilization update hook
too early) made intel_pstate_set_policy() clear the CPU's utilization
update hook before updating the policy attributes for it (and set the
hook again after doind that), but that involves invoking
synchronize_sched() and adds overhead to the CPU notifications
mentioned above and to the sched-RCU handling in general.

That extra overhead is arguably not necessary, because updating
policy attributes when the CPU's utilization update hook is active
should not lead to any adverse effects, so drop the clearing of
the hook from intel_pstate_set_policy() and make it check if
the hook has been set already when attempting to set it.

Fixes: bb6ab52f (intel_pstate: Do not set utilization update hook too early)
Reported-by: NJisheng Zhang <jszhang@marvell.com>
Tested-by: NJisheng Zhang <jszhang@marvell.com>
Tested-by: NDoug Smythies <dsmythies@telus.net>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Commit 920de6eb (ACPICA: Hardware: Enhance
acpi_hw_validate_register() with access_width/bit_offset awareness)
apparently exposed a latent bug, doorbell.access_width is initialized
to 64, but per Lv Zheng, it should be 4, and indeed, making that
change does bring pcc-cpufreq back to life.

Fixes: 920de6eb (ACPICA: Hardware: Enhance acpi_hw_validate_register() with access_width/bit_offset awareness)
Suggested-by: NLv Zheng <lv.zheng@intel.com>
Signed-off-by: NMike Galbraith <umgwanakikbuti@gmail.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The maximum turbo P-State used by the intel_pstate driver may be
limited by ACPI _PSS table entry 0.  After commit 9522a2ff
(cpufreq: intel_pstate: Enforce _PPC limits), the maximum performance
on servers will be capped by the _PSS table entry 0 by default.

Even though that is formally correct, it may lead to preformance
regressions in some cases.  Namely, if the _PSS table entry 0 is
not the maximum turbo P-State, performance measured after commit
9522a2ff will not match the performance measured before that
commit on the same system.

For this reason, modify the code to always use the maximum turbo
frequency as the one that corresponds to _PSS table entry 0 if turbo
is enabled in the BIOS.  This way, the performance levels from
before commit 9522a2ff will be restored on the affected systems.

Fixes: 9522a2ff (cpufreq: intel_pstate: Enforce _PPC limits)
Suggested-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: NSrinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
[ rjw : Changelog ]
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

When turbo is disabled, the ->set_policy() interface is broken.

For example, when turbo is disabled and cpuinfo.max = 2900000 (full
max turbo frequency), setting the limits results in frequency less
than the requested one:
Set 1000000 KHz results in 0700000 KHz
Set 1500000 KHz results in 1100000 KHz
Set 2000000 KHz results in  1500000 KHz

This is because the limits->max_perf fraction is calculated using
the max turbo frequency as the reference, but when the max P-State is
capped in intel_pstate_get_min_max(), the reference is not the max
turbo P-State. This results in reducing max P-State.

One option is to always use max turbo as reference for calculating
limits. But this will not be correct. By definition the intel_pstate
sysfs limits, shows percentage of available performance. So when
BIOS has disabled turbo, the available performance is max non turbo.
So the max_perf_pct should still show 100%.
Signed-off-by: NSrinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
[ rjw : Subject & changelog, rewrite in fewer lines of code ]
Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The limits->max_perf is rounded_up but immediately overwritten by
another assignment to limits->max_perf.

Move that operation to the correct location.

While here also added a pr_debug() call in ->set_policy to aid in
debugging.

Fixes: 785ee278 (cpufreq: intel_pstate: Fix limits->max_perf rounding error)
Signed-off-by: NSrinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
[ rjw : Subject & changelog ]
Cc: 4.4+ <stable@vger.kernel.org> # 4.4+
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The return value of clamp_val() has to be stored actually.

Fixes: b7898fda (cpufreq: Support for fast frequency switching)
Reported-by: NSteve Muckle <steve.muckle@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>

Downgrade pr_info to pr_debug for the "_PPC limits will be enforced"
message.

In server systems with many cores this message is annoying.
Signed-off-by: NSrinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
[ rjw: Changelog ]
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Most users of IS_ERR_VALUE() in the kernel are wrong, as they
pass an 'int' into a function that takes an 'unsigned long'
argument. This happens to work because the type is sign-extended
on 64-bit architectures before it gets converted into an
unsigned type.

However, anything that passes an 'unsigned short' or 'unsigned int'
argument into IS_ERR_VALUE() is guaranteed to be broken, as are
8-bit integers and types that are wider than 'unsigned long'.

Andrzej Hajda has already fixed a lot of the worst abusers that
were causing actual bugs, but it would be nice to prevent any
users that are not passing 'unsigned long' arguments.

This patch changes all users of IS_ERR_VALUE() that I could find
on 32-bit ARM randconfig builds and x86 allmodconfig. For the
moment, this doesn't change the definition of IS_ERR_VALUE()
because there are probably still architecture specific users
elsewhere.

Almost all the warnings I got are for files that are better off
using 'if (err)' or 'if (err < 0)'.
The only legitimate user I could find that we get a warning for
is the (32-bit only) freescale fman driver, so I did not remove
the IS_ERR_VALUE() there but changed the type to 'unsigned long'.
For 9pfs, I just worked around one user whose calling conventions
are so obscure that I did not dare change the behavior.

I was using this definition for testing:

 #define IS_ERR_VALUE(x) ((unsigned long*)NULL == (typeof (x)*)NULL && \
       unlikely((unsigned long long)(x) >= (unsigned long long)(typeof(x))-MAX_ERRNO))

which ends up making all 16-bit or wider types work correctly with
the most plausible interpretation of what IS_ERR_VALUE() was supposed
to return according to its users, but also causes a compile-time
warning for any users that do not pass an 'unsigned long' argument.

I suggested this approach earlier this year, but back then we ended
up deciding to just fix the users that are obviously broken. After
the initial warning that caused me to get involved in the discussion
(fs/gfs2/dir.c) showed up again in the mainline kernel, Linus
asked me to send the whole thing again.

[ Updated the 9p parts as per Al Viro  - Linus ]
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Cc: Andrzej Hajda <a.hajda@samsung.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lkml.org/lkml/2016/1/7/363
Link: https://lkml.org/lkml/2016/5/27/486
Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> # For nvmem part
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

simplified goto out in cpufreq_register_driver for increasing
code readability
Signed-off-by: NPankaj Gupta <pankaj.gupta@spreadtrum.com>
Signed-off-by: NSanjeev Yadav <sanjeev.yadav@spreadtrum.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

None of the cpufreq governors currently in the tree will ever fail
an invocation of the ->governor() callback with the event argument
equal to CPUFREQ_GOV_STOP (unless invoked with incorrect arguments
which doesn't matter anyway) and it is rather difficult to imagine
a valid reason for such a failure.

Accordingly, rearrange the code in the core to make it clear that
this call never fails.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>

None of the cpufreq governors currently in the tree will ever fail
an invocation of the ->governor() callback with the event argument
equal to CPUFREQ_GOV_POLICY_EXIT (unless invoked with incorrect
arguments which doesn't matter anyway) and it wouldn't really
make sense to fail it, because the caller won't be able to handle
that failure in a meaningful way.

Accordingly, rearrange the code in the core to make it clear that
this call never fails.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>

One of the if () statements in intel_pstate_set_policy() causes
another if () to be evaluated if the condition is true and it
doesn't do anything else, so merge the two if () statements into
one.

No functional changes.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NSrinivas Pandruvada <srinivas.pandruvada@linux.intel.com>

MT8173 cpufreq driver select of_cpufreq_power_cooling_register registering
cooling devices with dynamic power coefficient.
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NDawei Chien <dawei.chien@mediatek.com>
Signed-off-by: NEduardo Valentin <edubezval@gmail.com>

This patch replaces goto out with return in ls1x_cpufreq_probe().
Signed-off-by: NKelvin Cheung <keguang.zhang@gmail.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: linux-pm@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13056/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

This patch uses devm_kzalloc() instead of global structure.
Signed-off-by: NKelvin Cheung <keguang.zhang@gmail.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: linux-pm@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13055/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

This patch uses dev_get_platdata() to get the platform_data
instead of referencing it directly.
Signed-off-by: NKelvin Cheung <keguang.zhang@gmail.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: linux-pm@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13054/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

This patch replaces kzalloc() with kcalloc() when allocating
frequency table, and remove unnecessary 'out of memory' message.
Signed-off-by: NKelvin Cheung <keguang.zhang@gmail.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: linux-pm@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13053/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

This patch renames the file to loongson1-cpufreq.c,
and also includes some minor updates.
Signed-off-by: NKelvin Cheung <keguang.zhang@gmail.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: linux-pm@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13052/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

The comments and the core_busy variable name in
get_target_pstate_use_performance() are totally confusing,
so modify them to reflect what's going on.

The results of the computations should be the same as before.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Notice that get_avg_pstate() can use sample.core_avg_perf instead of
carrying the same division again, so make it do that.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The core_pct_busy field of struct sample actually contains the
average performace during the last sampling period (in percent)
and not the utilization of the core as suggested by its name
which is confusing.

For this reason, change the name of that field to core_avg_perf
and rename the function that computes its value accordingly.

Also notice that storing this value as percentage requires a costly
integer multiplication to be carried out in a hot path, so instead
store it as an "extended fixed point" value with more fraction bits
and update the code using it accordingly (it is better to change the
name of the field along with its meaning in one go than to make those
two changes separately, as that would likely lead to more
confusion).
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Currently, in intel_pstate_clear_update_util_hook(), after
clearing the utilization update hook, we leverage
synchronize_sched() to deal with synchronization, which
is a little bit time-costly because synchronize_sched()
has to wait for all the CPUs to go through a grace period.

Actually, the synchronize_sched() is not necessary if the utilization
update hook has not been set for the given CPU yet, so make the driver
check if that's the case and avoid the synchronize_sched() call then.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=116371Tested-by: NTian Ye <yex.tian@intel.com>
Signed-off-by: NChen Yu <yu.c.chen@intel.com>
[ rjw : Rebase ]
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

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>

When global and local pstate are equal in a powernv_target_index() call,
we don't queue a timer. But we may have timer already queued for future.
This could cause the timer to fire one additional time for no use.
Signed-off-by: NAkshay Adiga <akshay.adiga@linux.vnet.ibm.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Fix a WARN_ON caused by smp_call_function_any() when irq is disabled,
because of changes made in the patch ('cpufreq: powernv: Ramp-down
 global pstate slower than local-pstate')
https://patchwork.ozlabs.org/patch/612058/

 WARNING: CPU: 0 PID: 4 at kernel/smp.c:291
smp_call_function_single+0x170/0x180

 Call Trace:
 [c0000007f648f9f0] [c0000007f648fa90] 0xc0000007f648fa90 (unreliable)
 [c0000007f648fa30] [c0000000001430e0] smp_call_function_any+0x170/0x1c0
 [c0000007f648fa90] [c0000000007b4b00]
powernv_cpufreq_target_index+0xe0/0x250
 [c0000007f648fb00] [c0000000007ac9dc]
__cpufreq_driver_target+0x20c/0x3d0
 [c0000007f648fbc0] [c0000000007b1b4c] od_dbs_timer+0xcc/0x260
 [c0000007f648fc10] [c0000000007b3024] dbs_work_handler+0x54/0xa0
 [c0000007f648fc50] [c0000000000c49a8] process_one_work+0x1d8/0x590
 [c0000007f648fce0] [c0000000000c4e08] worker_thread+0xa8/0x660
 [c0000007f648fd80] [c0000000000cca88] kthread+0x108/0x130
 [c0000007f648fe30] [c0000000000095e8] ret_from_kernel_thread+0x5c/0x74

- Calling smp_call_function_any() with interrupt disabled (through
 spin_lock_irqsave) could cause a deadlock, as smp_call_function_any()
 relies on the IPI to complete. This is detected in the
 smp_call_function_any() call and hence the WARN_ON.

- As the spinlock (gpstates->lock) is only used to synchronize access of
 global_pstate_info  between timer irq handler and target_index calls. And
 the timer irq handler just try_locks() hence it would not cause a
 deadlock. Hence could do without making spinlocks irq safe.

- As the smp_call_function_any() is a blocking call and does not access
 global_pstates_info, it could reduce the critcal section by moving
 smp_call_function_any() after giving up the lock.
Reported-by: NAbdul Haleem <abdhalee@linux.vnet.linux.com>
Signed-off-by: NAkshay Adiga <akshay.adiga@linux.vnet.ibm.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

intel_pstate_get() contains a local variable that's initialized but
never used and it can be written in fewer lines of code, so clean
it up.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NSrinivas Pandruvada <srinivas.pandruvada@linux.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>

As reported in KBZ 69821:

"With CONFIG_HZ_PERIODIC=y cpu stays at the lowest frequcency 800MHz
 even if usage goes to 100%, frequency does not scale up, the governor
 in use is ondemand. Neither works conservative. Performance and
 userspace governors work as expected.

 With CONFIG_NO_HZ_IDLE or CONFIG_NO_HZ_FULL cpu scales up with ondemand
 as expected."

Analysis carried out by Chen Yu leads to the conclusion that the
observed issue is due to idle_time in dbs_update() representing a
negative number in which case the function will return 0 as the load
(unless load is greater than 0 for another CPU sharing the policy),
although that need not be the right choice.

Indeed, idle_time representing a negative number means that during
the last sampling interval the CPU was almost 100% busy on the rough
average, so 100 should be returned as the load in that case.

Modify the code accordingly and rearrange it to clarify the handling
of all of the special cases in it.  While at it, also avoid returning
zero as the load if time_elapsed is 0 (it doesn't really make sense
to return 0 then).

Link: https://bugzilla.kernel.org/show_bug.cgi?id=69821Tested-by: NChen Yu <yu.c.chen@intel.com>
Tested-by: NTimo Valtoaho <timo.valtoaho@gmail.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>

When HWP (hardware P states) feature is active, the ACPI _PSS and _PPC
is not used. So ignore processing for _PPC limits.
Signed-off-by: NSrinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Currently when performing random CPU hot-plugs and suspend-to-ram(S2R)
on systems using arm_big_little cpufreq driver, we get warnings similar
to something like below:

cpu cpu1: _opp_add: duplicate OPPs detected. Existing: freq: 600000000,
	volt: 800000, enabled: 1. New: freq: 600000000, volt: 800000, enabled: 1

This is mainly because the OPPs for the shared cpus are not set. We can
just use dev_pm_opp_of_cpumask_add_table in case the OPPs are obtained
from DT(arm_big_little_dt.c) or use dev_pm_opp_set_sharing_cpus if the
OPPs are obtained by other means like firmware(e.g. scpi-cpufreq.c)

Also now that the generic dev_pm_opp{,_of}_cpumask_remove_table can
handle removal of opp table and entries for all associated CPUs, we can
re-use dev_pm_opp{,_of}_cpumask_remove_table as free_opp_table in
cpufreq_arm_bL_ops.

This patch makes necessary changes to reuse the generic OPP functions for
{init,free}_opp_table and thereby eliminating the warnings.
Signed-off-by: NSudeep Holla <sudeep.holla@arm.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Add tango4 compatible string to the list.
Signed-off-by: NMarc Gonzalez <marc_gonzalez@sigmadesigns.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Currently, the userspace governor only updates frequency on GOV_LIMITS
if policy->cur falls outside policy->{min/max}. However, it is also
necessary to update current frequency on GOV_LIMITS to match the user
requested value if it can be achieved within the new policy->{max/min}.

This was previously the behaviour in the governor until commit d1922f02
("cpufreq: Simplify userspace governor") which incorrectly assumed that
policy->cur == user requested frequency via scaling_setspeed. This won't
be true if the user requested frequency falls outside policy->{min/max}.
Ex: a temporary thermal cap throttled the user requested frequency.

Fix this by storing the user requested frequency in a seperate variable.
The governor will then try to achieve this request on every GOV_LIMITS
change.

Fixes: d1922f02 (cpufreq: Simplify userspace governor)
Signed-off-by: NSai Gurrappadi <sgurrappadi@nvidia.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

After commit 8fa520af "intel_pstate: Remove freq calculation from
intel_pstate_calc_busy()" intel_pstate_get() calls get_avg_frequency()
to compute the average frequency, which is problematic for two reasons.

First, intel_pstate_get() may be invoked before the driver reads the
CPU feedback registers for the first time and if that happens,
get_avg_frequency() will attempt to divide by zero.

Second, the get_avg_frequency() call in intel_pstate_get() is racy
with respect to intel_pstate_sample() and it may end up returning
completely meaningless values for this reason.

Moreover, after commit 7349ec04 "intel_pstate: Move
intel_pstate_calc_busy() into get_target_pstate_use_performance()"
sample.core_pct_busy is never computed on Atom, but it is used in
intel_pstate_adjust_busy_pstate() in that case too.

To address those problems notice that if sample.core_pct_busy
was used in the average frequency computation carried out by
get_avg_frequency(), both the divide by zero problem and the
race with respect to intel_pstate_sample() would be avoided.

Accordingly, move the invocation of intel_pstate_calc_busy() from
get_target_pstate_use_performance() to intel_pstate_update_util(),
which also will take care of the uninitialized sample.core_pct_busy
on Atom, and modify get_avg_frequency() to use sample.core_pct_busy
as per the above.
Reported-by: Nkernel test robot <ying.huang@linux.intel.com>
Link: http://marc.info/?l=linux-kernel&m=146226437623173&w=4
Fixes: 8fa520af "intel_pstate: Remove freq calculation from intel_pstate_calc_busy()"
Fixes: 7349ec04 "intel_pstate: Move intel_pstate_calc_busy() into get_target_pstate_use_performance()"
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Commit 41cfd64c "Update frequencies of policy->cpus only from
->set_policy()" changed the way the intel_pstate driver's ->set_policy
callback updates the HWP (hardware-managed P-states) settings.
A side effect of it is that if those settings are modified on the
boot CPU during system suspend and wakeup, they will never be
restored during subsequent system resume.

To address this problem, allow cpufreq drivers that don't provide
->target or ->target_index callbacks to use ->suspend and ->resume
callbacks and add a ->resume callback to intel_pstate to restore
the HWP settings on the CPUs that belong to the given policy.

Fixes: 41cfd64c "Update frequencies of policy->cpus only from ->set_policy()"
Tested-by: NSrinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>

How we switch MMU context differs between hash and radix. For hash we
need to switch the SLB details and for radix we need to switch the PID
SPR.
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

The sti-cpufreq does unconditional registration of the cpufreq-dt driver
which causes issue on an multi-platform build. For example, on Vexpress
TC2 platform, we get the following error on boot:

cpu cpu0: OPP-v2 not supported
cpu cpu0: Not doing voltage scaling
cpu: dev_pm_opp_of_cpumask_add_table: couldn't find opp table
	for cpu:0, -19
cpu cpu0: dev_pm_opp_get_max_volt_latency: Invalid regulator (-6)
...
arm_big_little: bL_cpufreq_register: Failed registering platform driver:
		vexpress-spc, err: -17

The actual driver fails to initialise as cpufreq-dt is probed
successfully, which is incorrect. This issue can happen to any platform
not using cpufreq-dt in a multi-platform build.

This patch adds a check to do selective initialization of the driver.

Fixes: ab0ea257 (cpufreq: st: Provide runtime initialised driver for ST's platforms)
Signed-off-by: NSudeep Holla <sudeep.holla@arm.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Acked-by: NLee Jones <lee.jones@linaro.org>
Cc: 4.5+ <stable@vger.kernel.org> # 4.5+
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Move cpufreq bits for mvebu into drivers/cpufreq/ directory, that's
where they really belong to.

Compiled tested only.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

There are no more users of platform-data for cpufreq-dt driver, get rid
of it.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: NStephen Boyd <sboyd@codeaurora.org>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Existing platforms, which do not support operating-points-v2, can
explicitly tell the opp core that some of the CPUs share opp tables,
with help of dev_pm_opp_set_sharing_cpus().

For such platforms, explicitly ask the opp core to provide list of CPUs
sharing the opp table with current cpu device, before falling back to
platform data.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The name of the prev_cpu_wall field in struct cpu_dbs_info is
confusing, because it doesn't represent wall time, but the previous
update time as returned by get_cpu_idle_time() (that may be the
current value of jiffies_64 in some cases, for example).

Moreover, the names of some related variables in dbs_update() take
that confusion further.

Rename all of those things to make their names reflect the purpose
more accurately.  While at it, drop unnecessary parens from one of
the updated expressions.

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