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161 commits

Author SHA1 Message Date
Rafael J. Wysocki 1cbc99dfe5 Merge back cpufreq changes for v4.7. 2016-04-25 15:44:01 +02:00
Rafael J. Wysocki ffb810563c intel_pstate: Avoid getting stuck in high P-states when idle
Jörg Otte reports that commit a4675fbc4a (cpufreq: intel_pstate:
Replace timers with utilization update callbacks) caused the CPUs in
his Haswell-based system to stay in the very high frequency region
even if the system is completely idle.

That turns out to be an existing problem in the intel_pstate driver's
P-state selection algorithm for Core processors.  Namely, all
decisions made by that algorithm are based on the average frequency
of the CPU between sampling events and on the P-state requested on
the last invocation, so it may get stuck at a very hight frequency
even if the utilization of the CPU is very low (in fact, it may get
stuck in a inadequate P-state regardless of the CPU utilization).
The only way to kick it out of that limbo is a sufficiently long idle
period (3 times longer than the prescribed sampling interval), but if
that doesn't happen often enough (eg. due to a timing change like
after the above commit), the P-state of the CPU may be inadequate
pretty much all the time.

To address the most egregious manifestations of that issue, reset the
core_busy value used to determine the next P-state to request if the
utilization of the CPU, determined with the help of the MPERF
feedback register and the TSC, is below 1%.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=115771
Reported-and-tested-by: Jörg Otte <jrg.otte@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-04-10 05:59:10 +02:00
Joe Perches 4836df173a intel_pstate: Use pr_fmt
Prefix the output using the more common kernel style.

Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
[ rjw: Rebase ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-04-09 01:33:42 +02:00
Rafael J. Wysocki 22590efb98 intel_pstate: Avoid pointless FRAC_BITS shifts under div_fp()
There are multiple places in intel_pstate where int_tofp() is applied
to both arguments of div_fp(), but this is pointless, because int_tofp()
simply shifts its argument to the left by FRAC_BITS which mathematically
is equivalent to multuplication by 2^FRAC_BITS, so if this is done
to both arguments of a division, the extra factors will cancel each
other during that operation anyway.

Drop the pointless int_tofp() applied to div_fp() arguments throughout
the driver.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-04-09 01:25:58 +02:00
Rafael J. Wysocki 4b42fafc1c Merge branch 'pm-cpufreq-sched' into pm-cpufreq 2016-04-09 01:08:02 +02:00
Srinivas Pandruvada 13ad7701f9 cpufreq: intel_pstate: Documenation for structures
No code change. Only added kernel doc style comments for structures.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-04-05 03:39:05 +02:00
Srinivas Pandruvada 30a3915385 cpufreq: intel_pstate: fix inconsistency in setting policy limits
When user sets performance policy using cpufreq interface, it is possible
that because of policy->max limits, the actual performance is still
limited. But the current implementation will silently switch the
policy to powersave and start using powersave limits. If user modifies
any limits using intel_pstate sysfs, this is actually changing powersave
limits.

The current implementation tracks limits under powersave and performance
policy using two different variables. When policy->max is less than
policy->cpuinfo.max_freq, only powersave limit variable is used.

This fix causes the performance limits variable to be used always when
the policy is performance.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-04-05 03:37:13 +02:00
Rafael J. Wysocki 0bed612be6 cpufreq: sched: Helpers to add and remove update_util hooks
Replace the single helper for adding and removing cpufreq utilization
update hooks, cpufreq_set_update_util_data(), with a pair of helpers,
cpufreq_add_update_util_hook() and cpufreq_remove_update_util_hook(),
and modify the users of cpufreq_set_update_util_data() accordingly.

With the new helpers, the code using them doesn't need to worry
about the internals of struct update_util_data and in particular
it doesn't need to worry about populating the func field in it
properly upfront.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2016-04-02 01:08:43 +02:00
Rafael J. Wysocki febce40feb intel_pstate: Avoid extra invocation of intel_pstate_sample()
The initialization of intel_pstate for a given CPU involves populating
the fields of its struct cpudata that represent the previous sample,
but currently that is done in a problematic way.

Namely, intel_pstate_init_cpu() makes an extra call to
intel_pstate_sample() so it reads the current register values that
will be used to populate the "previous sample" record during the
next invocation of intel_pstate_sample().  However, after commit
a4675fbc4a (cpufreq: intel_pstate: Replace timers with utilization
update callbacks) that doesn't work for last_sample_time, because
the time value is passed to intel_pstate_sample() as an argument now.
Passing 0 to it from intel_pstate_init_cpu() is problematic, because
that causes cpu->last_sample_time == 0 to be visible in
get_target_pstate_use_performance() (and hence the extra
cpu->last_sample_time > 0 check in there) and effectively allows
the first invocation of intel_pstate_sample() from
intel_pstate_update_util() to happen immediately after the
initialization which may lead to a significant "turn on"
effect in the governor algorithm.

To mitigate that issue, rework the initialization to avoid the
extra intel_pstate_sample() call from intel_pstate_init_cpu().
Instead, make intel_pstate_sample() return false if it has been
called with cpu->sample.time equal to zero, which will make
intel_pstate_update_util() skip the sample in that case, and
reset cpu->sample.time from intel_pstate_set_update_util_hook()
to make the algorithm start properly every time the hook is set.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-04-02 01:06:21 +02:00
Rafael J. Wysocki bb6ab52f2b intel_pstate: Do not set utilization update hook too early
The utilization update hook in the intel_pstate driver is set too
early, as it only should be set after the policy has been fully
initialized by the core.  That may cause intel_pstate_update_util()
to use incorrect data and put the CPUs into incorrect P-states as
a result.

To prevent that from happening, make intel_pstate_set_policy() set
the utilization update hook instead of intel_pstate_init_cpu() so
intel_pstate_update_util() only runs when all things have been
initialized as appropriate.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-03-31 17:42:15 +02:00
Rafael J. Wysocki fdfdb2b130 intel_pstate: Do not call wrmsrl_on_cpu() with disabled interrupts
After commit a4675fbc4a (cpufreq: intel_pstate: Replace timers with
utilization update callbacks) wrmsrl_on_cpu() cannot be called in the
intel_pstate_adjust_busy_pstate() path as that is executed with
disabled interrupts.  However, atom_set_pstate() called from there
via intel_pstate_set_pstate() uses wrmsrl_on_cpu() to update the
IA32_PERF_CTL MSR which triggers the WARN_ON_ONCE() in
smp_call_function_single().

The reason why wrmsrl_on_cpu() is used by atom_set_pstate() is
because intel_pstate_set_pstate() calling it is also invoked during
the initialization and cleanup of the driver and in those cases it is
not guaranteed to be run on the CPU that is being updated.  However,
in the case when intel_pstate_set_pstate() is called by
intel_pstate_adjust_busy_pstate(), wrmsrl() can be used to update
the register safely.  Moreover, intel_pstate_set_pstate() already
contains code that only is executed if the function is called by
intel_pstate_adjust_busy_pstate() and there is a special argument
passed to it because of that.

To fix the problem at hand, rearrange the code taking the above
observations into account.

First, replace the ->set() callback in struct pstate_funcs with a
->get_val() one that will return the value to be written to the
IA32_PERF_CTL MSR without updating the register.

Second, split intel_pstate_set_pstate() into two functions,
intel_pstate_update_pstate() to be called by
intel_pstate_adjust_busy_pstate() that will contain all of the
intel_pstate_set_pstate() code which only needs to be executed in
that case and will use wrmsrl() to update the MSR (after obtaining
the value to write to it from the ->get_val() callback), and
intel_pstate_set_min_pstate() to be invoked during the
initialization and cleanup that will set the P-state to the
minimum one and will update the MSR using wrmsrl_on_cpu().

Finally, move the code shared between intel_pstate_update_pstate()
and intel_pstate_set_min_pstate() to a new static inline function
intel_pstate_record_pstate() and make them both call it.

Of course, that unifies the handling of the IA32_PERF_CTL MSR writes
between Atom and Core.

Fixes: a4675fbc4a (cpufreq: intel_pstate: Replace timers with utilization update callbacks)
Reported-and-tested-by: Josh Boyer <jwboyer@fedoraproject.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-03-20 00:37:09 +01:00
Rafael J. Wysocki 4fec7ad5f6 intel_pstate: Do not skip samples partially
If the current value of MPERF or the current value of TSC is the
same as the previous one, respectively, intel_pstate_sample() bails
out early and skips the sample.

However, intel_pstate_adjust_busy_pstate() is still called in that
case which is not correct, so modify intel_pstate_sample() to
return a bool value indicating whether or not the sample has been
taken and use it to decide whether or not to call
intel_pstate_adjust_busy_pstate().

While at it, remove redundant parentheses from the MPERF/TSC
check in intel_pstate_sample().

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
2016-03-11 00:07:51 +01:00
Philippe Longepe 8fa520af50 intel_pstate: Remove freq calculation from intel_pstate_calc_busy()
Use a helper function to compute the average pstate and call it only
where it is needed (only when tracing or in intel_pstate_get).

Signed-off-by: Philippe Longepe <philippe.longepe@linux.intel.com>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-03-11 00:04:58 +01:00
Philippe Longepe 7349ec0470 intel_pstate: Move intel_pstate_calc_busy() into get_target_pstate_use_performance()
The cpu_load algorithm doesn't need to invoke intel_pstate_calc_busy(),
so move that call from intel_pstate_sample() to
get_target_pstate_use_performance().

Signed-off-by: Philippe Longepe <philippe.longepe@linux.intel.com>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-03-11 00:04:58 +01:00
Philippe Longepe a158bed5dc intel_pstate: Optimize calculation for max/min_perf_adj
mul_fp(int_tofp(A), B) expands to:
((A << FRAC_BITS) * B) >> FRAC_BITS, so the same result can be obtained
via simple multiplication A * B.  Apply this observation to
max_perf * limits->max_perf and max_perf * limits->min_perf in
intel_pstate_get_min_max()."

Signed-off-by: Philippe Longepe <philippe.longepe@linux.intel.com>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-03-11 00:04:58 +01:00
Philippe Longepe b54a0dfd56 intel_pstate: Remove extra conversions in pid calculation
pid->setpoint and pid->deadband can be initialized in fixed point, so we
can avoid the int_tofp in pid_calc.

Signed-off-by: Philippe Longepe <philippe.longepe@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-03-11 00:04:42 +01:00
Rafael J. Wysocki a5acbfbd70 Merge branch 'pm-cpufreq-governor' into pm-cpufreq 2016-03-10 20:46:03 +01:00
Rafael J. Wysocki 08f511fd41 cpufreq: Reduce cpufreq_update_util() overhead a bit
Use the observation that cpufreq_update_util() is only called
by the scheduler with rq->lock held, so the callers of
cpufreq_set_update_util_data() can use synchronize_sched()
instead of synchronize_rcu() to wait for cpufreq_update_util()
to complete.  Moreover, if they are updated to do that,
rcu_read_(un)lock() calls in cpufreq_update_util() might be
replaced with rcu_read_(un)lock_sched(), respectively, but
those aren't really necessary, because the scheduler calls
that function from RCU-sched read-side critical sections
already.

In addition to that, if cpufreq_set_update_util_data() checks
the func field in the struct update_util_data before setting
the per-CPU pointer to it, the data->func check may be dropped
from cpufreq_update_util() as well.

Make the above changes to reduce the overhead from
cpufreq_update_util() in the scheduler paths invoking it
and to make the cleanup after removing its callbacks less
heavy-weight somewhat.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2016-03-09 15:07:58 +01:00
Rafael J. Wysocki a4675fbc4a cpufreq: intel_pstate: Replace timers with utilization update callbacks
Instead of using a per-CPU deferrable timer for utilization sampling
and P-states adjustments, 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, so the functional impact of this patch should not be significant.

Based on an earlier patch from Srinivas Pandruvada.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
2016-03-09 14:40:52 +01:00
Srinivas Pandruvada f05c966585 cpufreq: intel_pstate: disable HWP notifications
Disable HWP Interrupt notification before enabling HWP. Since we don't
have HWP interrupt handling for possible performance interrupts, there
is not much use of enabling HWP interrupts.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-02-26 22:15:38 +01:00
Srinivas Pandruvada 7791e4aa59 cpufreq: intel_pstate: Enable HWP by default
If the processor supports HWP, enable it by default without checking
for the cpu model. This will allow to enable HWP in all supported
processors without driver change.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-02-26 22:15:38 +01:00
Viresh Kumar 41cfd64cf4 intel_pstate: Update frequencies of policy->cpus only from ->set_policy()
The intel-pstate driver is using intel_pstate_hwp_set() from two
separate paths, i.e. ->set_policy() callback and sysfs update path for
the files present in /sys/devices/system/cpu/intel_pstate/ directory.

While an update to the sysfs path applies to all the CPUs being managed
by the driver (which essentially means all the online CPUs), the update
via the ->set_policy() callback applies to a smaller group of CPUs
managed by the policy for which ->set_policy() is called.

And so, intel_pstate_hwp_set() should update frequencies of only the
CPUs that are part of policy->cpus mask, while it is called from
->set_policy() callback.

In order to do that, add a parameter (cpumask) to intel_pstate_hwp_set()
and apply the frequency changes only to the concerned CPUs.

For ->set_policy() path, we are only concerned about policy->cpus, and
so policy->rwsem lock taken by the core prior to calling ->set_policy()
is enough to take care of any races. The larger lock acquired by
get_online_cpus() is required only for the updates to sysfs files.

Add another routine, intel_pstate_hwp_set_online_cpus(), and call it
from the sysfs update paths.

This also fixes a lockdep reported recently, where policy->rwsem and
get_online_cpus() could have been acquired in any order causing an ABBA
deadlock. The sequence of events leading to that was:

intel_pstate_init(...)
	...cpufreq_online(...)
		down_write(&policy->rwsem); // Locks policy->rwsem
		...
		cpufreq_init_policy(policy);
			...intel_pstate_hwp_set();
				get_online_cpus(); // Temporarily locks cpu_hotplug.lock
		...
		up_write(&policy->rwsem);

pm_suspend(...)
	...disable_nonboot_cpus()
		_cpu_down()
			cpu_hotplug_begin(); // Locks cpu_hotplug.lock
			__cpu_notify(CPU_DOWN_PREPARE, ...);
				...cpufreq_offline_prepare();
					down_write(&policy->rwsem); // Locks policy->rwsem

Reported-and-tested-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-02-23 01:10:44 +01:00
Rafael J. Wysocki 4157c2fc84 Merge back earlier cpufreq material for v4.5. 2015-12-21 03:15:15 +01:00
Prarit Bhargava 88b7b7c0c2 cpufreq: intel_pstate: Minor cleanup for FRAC_BITS
785ee27 ("cpufreq: intel_pstate: Fix limits->max_perf rounding error")
hardcodes the value of FRAC_BITS.  This patch fixes that minor issue.

Fixes: 785ee27881 (cpufreq: intel_pstate: Fix limits->max_perf rounding error)
Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-12-12 02:28:19 +01:00
Philippe Longepe 63d1d656a5 cpufreq: intel_pstate: Account for IO wait time
In cases where we have many IOs, the global load becomes low and the
load algorithm will decrease the requested P-State. Because of that,
the IOs overheads will increase and impact the IO performances.

To improve IO bound work, we can count the io-wait time as busy time
in calculating CPU busy.

This change uses get_cpu_iowait_time_us() to obtain the IO wait time value
and converts time into number of cycles spent waiting on IO at the TSC
rate. At the moment, this trick is only used for Atom.

Signed-off-by: Philippe Longepe <philippe.longepe@intel.com>
Signed-off-by: Stephane Gasparini <stephane.gasparini@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-12-10 01:17:40 +01:00
Philippe Longepe e70eed2b64 cpufreq: intel_pstate: Account for non C0 time
The current function to calculate cpu utilization uses the average P-state
ratio (APerf/Mperf) scaled by the ratio of the current P-state to the
max available non-turbo one. This leads to an overestimation of
utilization which causes higher-performance P-states to be selected more
often and that leads to increased energy consumption.

This is a problem for low-power systems, so it is better to use a
different utilization calculation algorithm for them.

Namely, the Percent Busy value (or load) can be estimated as the ratio of the
MPERF counter that runs at a constant rate only during active periods (C0) to
the time stamp counter (TSC) that also runs (at the same rate) during idle.
That is:

Percent Busy = 100 * (delta_mperf / delta_tsc)

Use this algorithm for platforms with SoCs based on the Airmont and Silvermont
Atom cores.

Signed-off-by: Philippe Longepe <philippe.longepe@intel.com>
Signed-off-by: Stephane Gasparini <stephane.gasparini@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-12-10 01:17:40 +01:00
Philippe Longepe 157386b6fc cpufreq: intel_pstate: Configurable algorithm to get target pstate
Target systems using different cpus have different power and performance
requirements. They may use different algorithms to get the next P-state
based on their power or performance preference.

For example, power-constrained systems may not want to use
high-performance P-states as aggressively as a full-size desktop or a
server platform. A server platform may want to run close to the max to
achieve better performance, while laptop-like systems may prefer
sacrificing performance for longer battery lifes.

For the above reasons, modify intel_pstate to allow the target P-state
selection algorithm to be depend on the CPU ID.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Philippe Longepe <philippe.longepe@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-12-10 01:17:40 +01:00
Alexandra Yates 584ee3dcb1 intel_pstate: Fix "performance" mode behavior with HWP enabled
If hardware-driven P-state selection (HWP) is enabled, the
"performance" mode of intel_pstate should only allow the processor
to use the highest-performance P-state available.  That is not
the case currently, so make it actually happen.

Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Alexandra Yates <alexandra.yates@linux.intel.com>
[ rjw: Subject and changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-11-25 23:37:44 +01:00
Prarit Bhargava 785ee27881 cpufreq: intel_pstate: Fix limits->max_perf rounding error
A rounding error was found in the calculation of limits->max_perf
in intel_pstate_set_policy(), which is used to calculate the max and min
pstate values in intel_pstate_get_min_max().  In that code,
limits->max_perf is truncated to 2 hex digits such that, for example,
0x169 was incorrectly calculated to 0x16 instead of 0x17.  This resulted in
the pstate being set one level too low.  This patch rounds the value of
limits->max_perf up instead of down so that the correct max pstate can
be reached.

Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-11-23 23:15:34 +01:00
Prarit Bhargava 8478f53946 cpufreq: intel_pstate: Fix limits->max_policy_pct rounding error
I have a Intel (6,63) processor with a "marketing" frequency (from
/proc/cpuinfo) of 2100MHz, and a max turbo frequency of 2600MHz.  I
can execute

cpupower frequency-set -g powersave --min 1200MHz --max 2100MHz

and the max_freq_pct is set to 80.  When adding load to the system I noticed
that the cpu frequency only reached 2000MHZ and not 2100MHz as expected.

This is because limits->max_policy_pct is calculated as 2100 * 100 /2600 = 80.7
and is rounded down to 80 when it should be rounded up to 81.  This patch
adds a DIV_ROUND_UP() which will return the correct value.

Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-11-23 23:14:10 +01:00
Philippe Longepe 1421df63c3 cpufreq: intel_pstate: Add separate support for Airmont cores
There are two flavors of Atom cores to be supported by intel_pstate,
Silvermont and Airmont, so make the driver distinguish between them by
adding separate frequency tables.

Separate the CPU defaults params for each of them and match the CPU IDs
against them as appropriate.

Signed-off-by: Philippe Longepe <philippe.longepe@linux.intel.com>
Signed-off-by: Stephane Gasparini <stephane.gasparini@linux.intel.com>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
[ rjw: Subject and changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-11-19 00:21:46 +01:00
Philippe Longepe 938d21a2a6 cpufreq: intel_pstate: Replace BYT with ATOM
Rename symbol and function names starting with "BYT" or "byt" to
start with "ATOM" or "atom", respectively, so as to make it clear
that they may apply to Atom in general and not just to Baytrail
(the goal is to support several Atoms architectures eventually).

This should not lead to any functional changes.

Signed-off-by: Philippe Longepe <philippe.longepe@linux.intel.com>
Signed-off-by: Stephane Gasparini <stephane.gasparini@linux.intel.com>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
[ rjw : Changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-11-19 00:21:46 +01:00
Rafael J. Wysocki 6ee11e413c Revert "cpufreq: intel_pstate: Use ACPI perf configuration"
Revert commit 37afb00032 (cpufreq: intel_pstate: Use ACPI perf
configuration) that is reported to cause a regression to happen
on a system where invalid data are returned by the ACPI _PSS object.

Since that commit makes assumptions regarding the _PSS output
correctness that may turn out to be overly optimistic in general,
there is a concern that it may introduce regression on more
systems, so it's better to revert it now and we'll revisit the
underlying issue in the next cycle with a more robust solution.

Conflicts:
        drivers/cpufreq/intel_pstate.c

Fixes: 37afb00032 (cpufreq: intel_pstate: Use ACPI perf configuration)
Reported-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-11-19 00:20:42 +01:00
Rafael J. Wysocki 799281a3c4 Revert "cpufreq: intel_pstate: Avoid calculation for max/min"
Revert commit 4ef4514870 (cpufreq: intel_pstate: Avoid calculation for
max/min) as it depends on commit 37afb00032 (cpufreq: intel_pstate: Use
ACPI perf configuration) that causes problems to happen and needs to be
reverted.

Conflicts:
	drivers/cpufreq/intel_pstate.c

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-11-18 23:29:56 +01:00
Prarit Bhargava 539342f60b intel_pstate: decrease number of "HWP enabled" messages
When booting an HWP enabled system the kernel displays one "HWP enabled"
message for each cpu.  The messages are superfluous since HWP is globally
enabled across all CPUs. This patch also adds an informational message
when HWP is disabled via intel_pstate=no_hwp.

Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-11-02 02:01:18 +01:00
Prarit Bhargava 51443fbf3d cpufreq: intel_pstate: Fix intel_pstate powersave min_perf_pct value
On systems that initialize the intel_pstate driver with the performance
governor, and then switch to the powersave governor will not transition to
lower cpu frequencies until /sys/devices/system/cpu/intel_pstate/min_perf_pct
is set to a low value.

The behavior of governor switching changed after commit a04759924e
("[cpufreq] intel_pstate: honor user space min_perf_pct override on
 resume").  The commit introduced tracking of performance percentage
changes via sysfs in order to restore userspace changes during
suspend/resume.  The problem occurs because the global values of the newly
introduced max_sysfs_pct and min_sysfs_pct are not lowered on the governor
change and this causes the powersave governor to inherit the performance
governor's settings.

A simple change would have been to reset max_sysfs_pct to 100 and
min_sysfs_pct to 0 on a governor change, which fixes the problem with
governor switching.  However, since we cannot break userspace[1] the fix
is now to give each governor its own limits storage area so that governor
specific changes are tracked.

I successfully tested this by booting with both the performance governor
and the powersave governor by default, and switching between the two
governors (while monitoring /sys/devices/system/cpu/intel_pstate/ values,
and looking at the output of cpupower frequency-info).  Suspend/Resume
testing was performed by Doug Smythies.

[1] Systems which suspend/resume using the unmaintained pm-utils package
will always transition to the performance governor before the suspend and
after the resume.  This means a system using the powersave governor will
go from powersave to performance, then suspend/resume, performance to
powersave.  The simple change during governor changes would have been
overwritten when the governor changed before and after the suspend/resume.
I have submitted https://bugzilla.redhat.com/show_bug.cgi?id=1271225
against Fedora to remove the 94cpufreq file that causes the problem.  It
should be noted that pm-utils is obsoleted with newer versions of systemd.

Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Acked-by: Kristen Carlson Accardi <kristen@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-10-16 22:35:11 +02:00
Rafael J. Wysocki 7855e10294 Merge back earlier cpufreq material for v4.4. 2015-10-16 22:12:02 +02:00
Srinivas Pandruvada 8e601a9f97 cpufreq: intel_pstate: Fix divide by zero on Knights Landing (KNL)
This is a workaround for KNL platform, where in some cases MPERF counter
will not have updated value before next read of MSR_IA32_MPERF. In this
case divide by zero will occur. This change ignores current sample for
busy calculation in this case.

Fixes: b34ef932d7 (intel_pstate: Knights Landing support)
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Acked-by: Kristen Carlson Accardi <kristen@linux.intel.com>
Cc: 4.1+ <stable@vger.kernel.org> # 4.1+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-10-15 22:46:33 +02:00
Srinivas Pandruvada 4ef4514870 cpufreq: intel_pstate: Avoid calculation for max/min
When requested from cpufreq to set policy, look into _pss and get
control values, instead of using max/min perf calculations. These
calculation misses next control state in boundary conditions.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Acked-by: Kristen Carlson Accardi <kristen@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-10-15 01:53:19 +02:00
Srinivas Pandruvada 37afb00032 cpufreq: intel_pstate: Use ACPI perf configuration
Use ACPI _PSS to limit the Intel P State turbo, max and min ratios.
This driver uses acpi processor perf lib calls to register performance.
The following logic is used to adjust Intel P state driver limits:
- If there is no turbo entry in _PSS, then disable Intel P state turbo
and limit to non turbo max
- If the non turbo max ratio is more than _PSS max non turbo value, then
set the max non turbo ratio to _PSS non turbo max
- If the min ratio is less than _PSS min then change the min ratio
matching _PSS min
- Scale the _PSS turbo frequency to max turbo frequency based on control
value.
This feature can be disabled by using kernel parameters:
intel_pstate=no_acpi

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Acked-by: Kristen Carlson Accardi <kristen@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-10-15 01:53:18 +02:00
Srinivas Pandruvada 3bcc6fa971 cpufreq: intel-pstate: Use separate max pstate for scaling
Systems with configurable TDP have multiple max non turbo p state. Intel
P state uses max non turbo P state for scaling. But using the real max
non turbo p state causes underestimation of next P state. So using
the physical max non turbo P state as before for scaling.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Acked-by: Kristen Carlson Accardi <kristen@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-10-15 01:53:18 +02:00
Srinivas Pandruvada 6a35fc2d6c cpufreq: intel_pstate: get P1 from TAR when available
After Ivybridge, the max non turbo ratio obtained from platform info msr
is not always guaranteed P1 on client platforms. The max non turbo
activation ratio (TAR), determines the max for the current level of TDP.
The ratio in platform info is physical max. The TAR MSR can be locked,
so updating this value is not possible on all platforms.
This change gets this ratio from MSR TURBO_ACTIVATION_RATIO if
available,
but also do some sanity checking to make sure that this value is
correct.
The sanity check involves reading the TDP ratio for the current tdp
control value when platform has configurable TDP present and matching
TAC
with this.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Acked-by: Kristen Carlson Accardi <kristen@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-10-15 01:53:18 +02:00
Rafael J. Wysocki 3e66c4b860 Merge branch 'pm-cpufreq'
* pm-cpufreq:
  intel_pstate: fix PCT_TO_HWP macro
  intel_pstate: Fix user input of min/max to legal policy region
  cpufreq-dt: add suspend frequency support
  cpufreq: allow cpufreq_generic_suspend() to work without suspend frequency
  cpufreq: Use __func__ to print function's name
  cpufreq: staticize cpufreq_cpu_get_raw()
  cpufreq: Add ARM_MT8173_CPUFREQ dependency on THERMAL
  cpufreq: dt: Tolerance applies on both sides of target voltage
  cpufreq: dt: Print error on failing to mark OPPs as shared
  cpufreq: dt: Check OPP count before marking them shared
2015-09-11 15:37:25 +02:00
Kristen Carlson Accardi 74da56ce5c intel_pstate: fix PCT_TO_HWP macro
PCT_TO_HWP does not take the actual range of pstates exported
by HWP_CAPABILITIES in account, and is broken on most platforms.
Remove the macro and set the min and max pstate for hwp by
determining the range and adjusting by the min and max percent
limits values.

Signed-off-by: Kristen Carlson Accardi <kristen@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-09-09 22:56:18 +02:00
Chen Yu 43717aadd2 intel_pstate: Fix user input of min/max to legal policy region
In current code, max_perf_pct might be smaller than min_perf_pct
by improper user input:

$ grep . /sys/devices/system/cpu/intel_pstate/m*_perf_pct
/sys/devices/system/cpu/intel_pstate/max_perf_pct:100
/sys/devices/system/cpu/intel_pstate/min_perf_pct:100

$ echo 80 > /sys/devices/system/cpu/intel_pstate/max_perf_pct

$ grep . /sys/devices/system/cpu/intel_pstate/m*_perf_pct
/sys/devices/system/cpu/intel_pstate/max_perf_pct:80
/sys/devices/system/cpu/intel_pstate/min_perf_pct:100

Fix this problem by 2 steps:
 1. Normalize the user input to [min_policy, max_policy].
 2. Make sure max_perf_pct>=min_perf_pct, suggested by Seiichi Ikarashi.

Signed-off-by: Chen Yu <yu.c.chen@intel.com>
Acked-by: Kristen Carlson Accardi <kristen@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-09-09 22:55:23 +02:00
Linus Torvalds ae98207309 Power management and ACPI material for v4.3-rc1
- ACPICA update to upstream revision 20150818 including method
    tracing extensions to allow more in-depth AML debugging in the
    kernel and a number of assorted fixes and cleanups (Bob Moore,
    Lv Zheng, Markus Elfring).
 
  - ACPI sysfs code updates and a documentation update related to
    AML method tracing (Lv Zheng).
 
  - ACPI EC driver fix related to serialized evaluations of _Qxx
    methods and ACPI tools updates allowing the EC userspace tool
    to be built from the kernel source (Lv Zheng).
 
  - ACPI processor driver updates preparing it for future
    introduction of CPPC support and ACPI PCC mailbox driver
    updates (Ashwin Chaugule).
 
  - ACPI interrupts enumeration fix for a regression related
    to the handling of IRQ attribute conflicts between MADT
    and the ACPI namespace (Jiang Liu).
 
  - Fixes related to ACPI device PM (Mika Westerberg, Srinidhi Kasagar).
 
  - ACPI device registration code reorganization to separate the
    sysfs-related code and bus type operations from the rest (Rafael
    J Wysocki).
 
  - Assorted cleanups in the ACPI core (Jarkko Nikula, Mathias Krause,
    Andy Shevchenko, Rafael J Wysocki, Nicolas Iooss).
 
  - ACPI cpufreq driver and ia64 cpufreq driver fixes and cleanups
    (Pan Xinhui, Rafael J Wysocki).
 
  - cpufreq core cleanups on top of the previous changes allowing it
    to preseve its sysfs directories over system suspend/resume (Viresh
    Kumar, Rafael J Wysocki, Sebastian Andrzej Siewior).
 
  - cpufreq fixes and cleanups related to governors (Viresh Kumar).
 
  - cpufreq updates (core and the cpufreq-dt driver) related to the
    turbo/boost mode support (Viresh Kumar, Bartlomiej Zolnierkiewicz).
 
  - New DT bindings for Operating Performance Points (OPP), support
    for them in the OPP framework and in the cpufreq-dt driver plus
    related OPP framework fixes and cleanups (Viresh Kumar).
 
  - cpufreq powernv driver updates (Shilpasri G Bhat).
 
  - New cpufreq driver for Mediatek MT8173 (Pi-Cheng Chen).
 
  - Assorted cpufreq driver (speedstep-lib, sfi, integrator) cleanups
    and fixes (Abhilash Jindal, Andrzej Hajda, Cristian Ardelean).
 
  - intel_pstate driver updates including Skylake-S support, support
    for enabling HW P-states per CPU and an additional vendor bypass
    list entry (Kristen Carlson Accardi, Chen Yu, Ethan Zhao).
 
  - cpuidle core fixes related to the handling of coupled idle states
    (Xunlei Pang).
 
  - intel_idle driver updates including Skylake Client support and
    support for freeze-mode-specific idle states (Len Brown).
 
  - Driver core updates related to power management (Andy Shevchenko,
    Rafael J Wysocki).
 
  - Generic power domains framework fixes and cleanups (Jon Hunter,
    Geert Uytterhoeven, Rajendra Nayak, Ulf Hansson).
 
  - Device PM QoS framework update to allow the latency tolerance
    setting to be exposed to user space via sysfs (Mika Westerberg).
 
  - devfreq support for PPMUv2 in Exynos5433 and a fix for an incorrect
    exynos-ppmu DT binding (Chanwoo Choi, Javier Martinez Canillas).
 
  - System sleep support updates (Alan Stern, Len Brown, SungEun Kim).
 
  - rockchip-io AVS support updates (Heiko Stuebner).
 
  - PM core clocks support fixup (Colin Ian King).
 
  - Power capping RAPL driver update including support for Skylake H/S
    and Broadwell-H (Radivoje Jovanovic, Seiichi Ikarashi).
 
  - Generic device properties framework fixes related to the handling
    of static (driver-provided) property sets (Andy Shevchenko).
 
  - turbostat and cpupower updates (Len Brown, Shilpasri G Bhat,
    Shreyas B Prabhu).
 
 /
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Merge tag 'pm+acpi-4.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management and ACPI updates from Rafael Wysocki:
 "From the number of commits perspective, the biggest items are ACPICA
  and cpufreq changes with the latter taking the lead (over 50 commits).

  On the cpufreq front, there are many cleanups and minor fixes in the
  core and governors, driver updates etc.  We also have a new cpufreq
  driver for Mediatek MT8173 chips.

  ACPICA mostly updates its debug infrastructure and adds a number of
  fixes and cleanups for a good measure.

  The Operating Performance Points (OPP) framework is updated with new
  DT bindings and support for them among other things.

  We have a few updates of the generic power domains framework and a
  reorganization of the ACPI device enumeration code and bus type
  operations.

  And a lot of fixes and cleanups all over.

  Included is one branch from the MFD tree as it contains some
  PM-related driver core and ACPI PM changes a few other commits are
  based on.

  Specifics:

   - ACPICA update to upstream revision 20150818 including method
     tracing extensions to allow more in-depth AML debugging in the
     kernel and a number of assorted fixes and cleanups (Bob Moore, Lv
     Zheng, Markus Elfring).

   - ACPI sysfs code updates and a documentation update related to AML
     method tracing (Lv Zheng).

   - ACPI EC driver fix related to serialized evaluations of _Qxx
     methods and ACPI tools updates allowing the EC userspace tool to be
     built from the kernel source (Lv Zheng).

   - ACPI processor driver updates preparing it for future introduction
     of CPPC support and ACPI PCC mailbox driver updates (Ashwin
     Chaugule).

   - ACPI interrupts enumeration fix for a regression related to the
     handling of IRQ attribute conflicts between MADT and the ACPI
     namespace (Jiang Liu).

   - Fixes related to ACPI device PM (Mika Westerberg, Srinidhi
     Kasagar).

   - ACPI device registration code reorganization to separate the
     sysfs-related code and bus type operations from the rest (Rafael J
     Wysocki).

   - Assorted cleanups in the ACPI core (Jarkko Nikula, Mathias Krause,
     Andy Shevchenko, Rafael J Wysocki, Nicolas Iooss).

   - ACPI cpufreq driver and ia64 cpufreq driver fixes and cleanups (Pan
     Xinhui, Rafael J Wysocki).

   - cpufreq core cleanups on top of the previous changes allowing it to
     preseve its sysfs directories over system suspend/resume (Viresh
     Kumar, Rafael J Wysocki, Sebastian Andrzej Siewior).

   - cpufreq fixes and cleanups related to governors (Viresh Kumar).

   - cpufreq updates (core and the cpufreq-dt driver) related to the
     turbo/boost mode support (Viresh Kumar, Bartlomiej Zolnierkiewicz).

   - New DT bindings for Operating Performance Points (OPP), support for
     them in the OPP framework and in the cpufreq-dt driver plus related
     OPP framework fixes and cleanups (Viresh Kumar).

   - cpufreq powernv driver updates (Shilpasri G Bhat).

   - New cpufreq driver for Mediatek MT8173 (Pi-Cheng Chen).

   - Assorted cpufreq driver (speedstep-lib, sfi, integrator) cleanups
     and fixes (Abhilash Jindal, Andrzej Hajda, Cristian Ardelean).

   - intel_pstate driver updates including Skylake-S support, support
     for enabling HW P-states per CPU and an additional vendor bypass
     list entry (Kristen Carlson Accardi, Chen Yu, Ethan Zhao).

   - cpuidle core fixes related to the handling of coupled idle states
     (Xunlei Pang).

   - intel_idle driver updates including Skylake Client support and
     support for freeze-mode-specific idle states (Len Brown).

   - Driver core updates related to power management (Andy Shevchenko,
     Rafael J Wysocki).

   - Generic power domains framework fixes and cleanups (Jon Hunter,
     Geert Uytterhoeven, Rajendra Nayak, Ulf Hansson).

   - Device PM QoS framework update to allow the latency tolerance
     setting to be exposed to user space via sysfs (Mika Westerberg).

   - devfreq support for PPMUv2 in Exynos5433 and a fix for an incorrect
     exynos-ppmu DT binding (Chanwoo Choi, Javier Martinez Canillas).

   - System sleep support updates (Alan Stern, Len Brown, SungEun Kim).

   - rockchip-io AVS support updates (Heiko Stuebner).

   - PM core clocks support fixup (Colin Ian King).

   - Power capping RAPL driver update including support for Skylake H/S
     and Broadwell-H (Radivoje Jovanovic, Seiichi Ikarashi).

   - Generic device properties framework fixes related to the handling
     of static (driver-provided) property sets (Andy Shevchenko).

   - turbostat and cpupower updates (Len Brown, Shilpasri G Bhat,
     Shreyas B Prabhu)"

* tag 'pm+acpi-4.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (180 commits)
  cpufreq: speedstep-lib: Use monotonic clock
  cpufreq: powernv: Increase the verbosity of OCC console messages
  cpufreq: sfi: use kmemdup rather than duplicating its implementation
  cpufreq: drop !cpufreq_driver check from cpufreq_parse_governor()
  cpufreq: rename cpufreq_real_policy as cpufreq_user_policy
  cpufreq: remove redundant 'policy' field from user_policy
  cpufreq: remove redundant 'governor' field from user_policy
  cpufreq: update user_policy.* on success
  cpufreq: use memcpy() to copy policy
  cpufreq: remove redundant CPUFREQ_INCOMPATIBLE notifier event
  cpufreq: mediatek: Add MT8173 cpufreq driver
  dt-bindings: mediatek: Add MT8173 CPU DVFS clock bindings
  PM / Domains: Fix typo in description of genpd_dev_pm_detach()
  PM / Domains: Remove unusable governor dummies
  PM / Domains: Make pm_genpd_init() available to modules
  PM / domains: Align column headers and data in pm_genpd_summary output
  powercap / RAPL: disable the 2nd power limit properly
  tools: cpupower: Fix error when running cpupower monitor
  PM / OPP: Drop unlikely before IS_ERR(_OR_NULL)
  PM / OPP: Fix static checker warning (broken 64bit big endian systems)
  ...
2015-09-01 19:45:46 -07:00
Ingo Molnar a5dd192496 Merge branch 'x86/urgent' into x86/asm to fix up conflicts and to pick up fixes
Conflicts:
	arch/x86/entry/entry_64_compat.S
	arch/x86/math-emu/get_address.c

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-08-18 09:39:47 +02:00
Ethan Zhao 5aecc3c8a2 intel_pstate: append more Oracle OEM table id to vendor bypass list
Append more Oracle X86 servers that have their own power management,

SUN FIRE X4275 M3
SUN FIRE X4170 M3
and
SUN FIRE X6-2

Signed-off-by: Ethan Zhao <ethan.zhao@oracle.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by:  Kristen Carlson Accardi <kristen@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-08-07 03:29:54 +02:00
Kristen Carlson Accardi 1c93912387 intel_pstate: Add SKY-S support
Whitelist the SKL-S processor

Signed-off-by: Kristen Carlson Accardi <kristen@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-08-07 03:28:43 +02:00
Chen Yu 144c8e172b intel_pstate: Fix possible overflow complained by Coverity
Coverity scanning performed on intel_pstate.c shows possible
overflow when doing left shifting:
val = pstate << 8;
since pstate is of type integer, while val is of u64, left shifting
pstate might lead to potential loss of upper bits. Say, if pstate equals
0x4000 0000, after pstate << 8 we will get zero assigned to val.
Although pstate will not likely be that big, this patch cast the left
operand to u64 before performing the left shift, to avoid complaining
from Coverity.

Reported-by: Coquard, Christophe <christophe.coquard@intel.com>
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-07-31 23:25:16 +02:00