Commit Graph

1779 Commits

Author SHA1 Message Date
Rafael J. Wysocki 5f2f88e330 Merge branches 'pm-opp-fixes', 'pm-cpufreq-fixes' and 'pm-cpuidle-fixes'
* pm-opp-fixes:
  PM / OPP: Remove useless check

* pm-cpufreq-fixes:
  intel_pstate: Fix intel_pstate_get()
  cpufreq: intel_pstate: Fix HWP on boot CPU after system resume
  cpufreq: st: enable selective initialization based on the platform

* pm-cpuidle-fixes:
  ARM: cpuidle: Pass on arm_cpuidle_suspend()'s return value
2016-05-06 13:16:22 +02:00
Rafael J. Wysocki 6d45b719cb intel_pstate: Fix intel_pstate_get()
After commit 8fa520af50 "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 7349ec0470 "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: kernel test robot <ying.huang@linux.intel.com>
Link: http://marc.info/?l=linux-kernel&m=146226437623173&w=4
Fixes: 8fa520af50 "intel_pstate: Remove freq calculation from intel_pstate_calc_busy()"
Fixes: 7349ec0470 "intel_pstate: Move intel_pstate_calc_busy() into get_target_pstate_use_performance()"
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-05-04 14:09:16 +02:00
Rafael J. Wysocki ba41e1bc28 cpufreq: intel_pstate: Fix HWP on boot CPU after system resume
Commit 41cfd64cf4 "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: 41cfd64cf4 "Update frequencies of policy->cpus only from ->set_policy()"
Tested-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-05-02 13:48:15 +02:00
Rafael J. Wysocki 81be193b7e Merge branch 'pm-cpufreq-fixes'
* pm-cpufreq-fixes:
  cpufreq: intel_pstate: Fix processing for turbo activation ratio
  Revert "cpufreq: governor: Fix negative idle_time when configured with CONFIG_HZ_PERIODIC"
2016-04-29 14:22:25 +02:00
Sudeep Holla 2482bc31ca cpufreq: st: enable selective initialization based on the platform
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: ab0ea257fc (cpufreq: st: Provide runtime initialised driver for ST's platforms)
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Lee Jones <lee.jones@linaro.org>
Cc: 4.5+ <stable@vger.kernel.org> # 4.5+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-04-28 15:25:56 +02:00
Srinivas Pandruvada 1becf03545 cpufreq: intel_pstate: Fix processing for turbo activation ratio
When the config TDP level is not nominal (level = 0), the MSR values for
reading level 1 and level 2 ratios contain power in low 14 bits and actual
ratio bits are at bits [23:16]. The current processing for level 1 and
level 2 is wrong as there is no shift done to get actual ratio.

Fixes: 6a35fc2d6c (cpufreq: intel_pstate: get P1 from TAR when available)
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Cc: 4.4+ <stable@vger.kernel.org> # 4.4+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-04-25 23:39:09 +02:00
Rafael J. Wysocki 94862a62df Revert "cpufreq: governor: Fix negative idle_time when configured with CONFIG_HZ_PERIODIC"
Revert commit 0df35026c6 (cpufreq: governor: Fix negative idle_time
when configured with CONFIG_HZ_PERIODIC) that introduced a regression
by causing the ondemand cpufreq governor to misbehave for
CONFIG_TICK_CPU_ACCOUNTING unset (the frequency goes up to the max at
one point and stays there indefinitely).

The revert takes subsequent modifications of the code in question into
account.

Fixes: 0df35026c6 (cpufreq: governor: Fix negative idle_time when configured with CONFIG_HZ_PERIODIC)
Link: https://bugzilla.kernel.org/show_bug.cgi?id=115261
Reported-and-tested-by: Timo Valtoaho <timo.valtoaho@gmail.com>
Cc: 4.5+ <stable@vger.kernel.org> # 4.5+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-04-25 02:39:20 +02:00
Rafael J. Wysocki 395da1259a Merge branch 'pm-cpufreq-fixes'
* pm-cpufreq-fixes:
  cpufreq: Abort cpufreq_update_current_freq() for cpufreq_suspended set
  intel_pstate: Avoid getting stuck in high P-states when idle
2016-04-21 20:57:46 +02:00
Rafael J. Wysocki c9d9c929e6 cpufreq: Abort cpufreq_update_current_freq() for cpufreq_suspended set
Since governor operations are generally skipped if cpufreq_suspended
is set, cpufreq_start_governor() should do nothing in that case.

That function is called in the cpufreq_online() path, and may also
be called from cpufreq_offline() in some cases, which are invoked
by the nonboot CPUs disabing/enabling code during system suspend
to RAM and resume.  That happens when all devices have been
suspended, so if the cpufreq driver relies on things like I2C to
get the current frequency, it may not be ready to do that then.

To prevent problems from happening for this reason, make
cpufreq_update_current_freq(), which is the only function invoked
by cpufreq_start_governor() that doesn't check cpufreq_suspended
already, return 0 upfront if cpufreq_suspended is set.

Fixes: 3bbf8fe3ae (cpufreq: Always update current frequency before startig governor)
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-04-18 23:47:42 +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
Rafael J. Wysocki fa81e66ec8 Merge branches 'pm-cpufreq', 'pm-cpuidle' and 'acpi-cppc'
* pm-cpufreq:
  cpufreq: dt: Drop stale comment
  cpufreq: intel_pstate: Documenation for structures
  cpufreq: intel_pstate: fix inconsistency in setting policy limits
  intel_pstate: Avoid extra invocation of intel_pstate_sample()
  intel_pstate: Do not set utilization update hook too early

* pm-cpuidle:
  intel_idle: Add KBL support
  intel_idle: Add SKX support
  intel_idle: Clean up all registered devices on exit.
  intel_idle: Propagate hot plug errors.
  intel_idle: Don't overreact to a cpuidle registration failure.
  intel_idle: Setup the timer broadcast only on successful driver load.
  intel_idle: Avoid a double free of the per-CPU data.
  intel_idle: Fix dangling registration on error path.
  intel_idle: Fix deallocation order on the driver exit path.
  intel_idle: Remove redundant initialization calls.
  intel_idle: Fix a helper function's return value.
  intel_idle: remove useless return from void function.

* acpi-cppc:
  mailbox: pcc: Don't access an unmapped memory address space
2016-04-08 21:46:05 +02:00
Viresh Kumar b318556479 cpufreq: dt: Drop stale comment
The comment in file header doesn't hold true anymore, drop it.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-04-05 03:40:44 +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 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
Linus Torvalds 3d66c6ba3f Power management and ACPI material for v4.6-rc1, part 2
- Fix for an intel_pstate driver issue related to the handling of
    MSR updates uncovered by the recent cpufreq rework (Rafael Wysocki).
 
  - cpufreq core cleanups related to starting governors and frequency
    synchronization during resume from system suspend and a locking
    fix for cpufreq_quick_get() (Rafael Wysocki, Richard Cochran).
 
  - acpi-cpufreq and powernv cpufreq driver updates (Jisheng Zhang,
    Michael Neuling, Richard Cochran, Shilpasri Bhat).
 
  - intel_idle driver update preventing some Skylake-H systems
    from hanging during initialization by disabling deep C-states
    mishandled by the platform in the problematic configurations (Len
    Brown).
 
  - Intel Xeon Phi Processor x200 support for intel_idle (Dasaratharaman
    Chandramouli).
 
  - cpuidle menu governor updates to make it always honor PM QoS
    latency constraints (and prevent C1 from being used as the
    fallback C-state on x86 when they are set below its exit latency)
    and to restore the previous behavior to fall back to C1 if the next
    timer event is set far enough in the future that was changed in 4.4
    which led to an energy consumption regression (Rik van Riel, Rafael
    Wysocki).
 
  - New device ID for a future AMD UART controller in the ACPI driver
    for AMD SoCs (Wang Hongcheng).
 
  - Rockchip rk3399 support for the rockchip-io-domain adaptive voltage
    scaling (AVS) driver (David Wu).
 
  - ACPI PCI resources management fix for the handling of IO space
    resources on architectures where the IO space is memory mapped
    (IA64 and ARM64) broken by the introduction of common ACPI
    resources parsing for PCI host bridges in 4.4 (Lorenzo Pieralisi).
 
  - Fix for the ACPI backend of the generic device properties API
    to make it parse non-device (data node only) children of an
    ACPI device correctly (Irina Tirdea).
 
  - Fixes for the handling of global suspend flags (introduced in 4.4)
    during hibernation and resume from it (Lukas Wunner).
 
  - Support for obtaining configuration information from Device Trees
    in the PM clocks framework (Jon Hunter).
 
  - ACPI _DSM helper code and devfreq framework cleanups (Colin Ian
    King, Geert Uytterhoeven).
 
 /
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Merge tag 'pm+acpi-4.6-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull more power management and ACPI updates from Rafael Wysocki:
 "The second batch of power management and ACPI updates for v4.6.

  Included are fixups on top of the previous PM/ACPI pull request and
  other material that didn't make into it but still should go into 4.6.

  Among other things, there's a fix for an intel_pstate driver issue
  uncovered by recent cpufreq changes, a workaround for a boot hang on
  Skylake-H related to the handling of deep C-states by the platform and
  a PCI/ACPI fix for the handling of IO port resources on non-x86
  architectures plus some new device IDs and similar.

  Specifics:

   - Fix for an intel_pstate driver issue related to the handling of MSR
     updates uncovered by the recent cpufreq rework (Rafael Wysocki).

   - cpufreq core cleanups related to starting governors and frequency
     synchronization during resume from system suspend and a locking fix
     for cpufreq_quick_get() (Rafael Wysocki, Richard Cochran).

   - acpi-cpufreq and powernv cpufreq driver updates (Jisheng Zhang,
     Michael Neuling, Richard Cochran, Shilpasri Bhat).

   - intel_idle driver update preventing some Skylake-H systems from
     hanging during initialization by disabling deep C-states mishandled
     by the platform in the problematic configurations (Len Brown).

   - Intel Xeon Phi Processor x200 support for intel_idle
     (Dasaratharaman Chandramouli).

   - cpuidle menu governor updates to make it always honor PM QoS
     latency constraints (and prevent C1 from being used as the fallback
     C-state on x86 when they are set below its exit latency) and to
     restore the previous behavior to fall back to C1 if the next timer
     event is set far enough in the future that was changed in 4.4 which
     led to an energy consumption regression (Rik van Riel, Rafael
     Wysocki).

   - New device ID for a future AMD UART controller in the ACPI driver
     for AMD SoCs (Wang Hongcheng).

   - Rockchip rk3399 support for the rockchip-io-domain adaptive voltage
     scaling (AVS) driver (David Wu).

   - ACPI PCI resources management fix for the handling of IO space
     resources on architectures where the IO space is memory mapped
     (IA64 and ARM64) broken by the introduction of common ACPI
     resources parsing for PCI host bridges in 4.4 (Lorenzo Pieralisi).

   - Fix for the ACPI backend of the generic device properties API to
     make it parse non-device (data node only) children of an ACPI
     device correctly (Irina Tirdea).

   - Fixes for the handling of global suspend flags (introduced in 4.4)
     during hibernation and resume from it (Lukas Wunner).

   - Support for obtaining configuration information from Device Trees
     in the PM clocks framework (Jon Hunter).

   - ACPI _DSM helper code and devfreq framework cleanups (Colin Ian
     King, Geert Uytterhoeven)"

* tag 'pm+acpi-4.6-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (23 commits)
  PM / AVS: rockchip-io: add io selectors and supplies for rk3399
  intel_idle: Support for Intel Xeon Phi Processor x200 Product Family
  intel_idle: prevent SKL-H boot failure when C8+C9+C10 enabled
  ACPI / PM: Runtime resume devices when waking from hibernate
  PM / sleep: Clear pm_suspend_global_flags upon hibernate
  cpufreq: governor: Always schedule work on the CPU running update
  cpufreq: Always update current frequency before startig governor
  cpufreq: Introduce cpufreq_update_current_freq()
  cpufreq: Introduce cpufreq_start_governor()
  cpufreq: powernv: Add sysfs attributes to show throttle stats
  cpufreq: acpi-cpufreq: make Intel/AMD MSR access, io port access static
  PCI: ACPI: IA64: fix IO port generic range check
  ACPI / util: cast data to u64 before shifting to fix sign extension
  cpufreq: powernv: Define per_cpu chip pointer to optimize hot-path
  cpuidle: menu: Fall back to polling if next timer event is near
  cpufreq: acpi-cpufreq: Clean up hot plug notifier callback
  intel_pstate: Do not call wrmsrl_on_cpu() with disabled interrupts
  cpufreq: Make cpufreq_quick_get() safe to call
  ACPI / property: fix data node parsing in acpi_get_next_subnode()
  ACPI / APD: Add device HID for future AMD UART controller
  ...
2016-03-24 22:59:58 -07:00
Rafael J. Wysocki 33068b61f8 Merge branches 'pm-cpufreq' and 'pm-cpuidle'
* pm-cpufreq:
  cpufreq: governor: Always schedule work on the CPU running update
  cpufreq: Always update current frequency before startig governor
  cpufreq: Introduce cpufreq_update_current_freq()
  cpufreq: Introduce cpufreq_start_governor()
  cpufreq: powernv: Add sysfs attributes to show throttle stats
  cpufreq: acpi-cpufreq: make Intel/AMD MSR access, io port access static
  cpufreq: powernv: Define per_cpu chip pointer to optimize hot-path
  cpufreq: acpi-cpufreq: Clean up hot plug notifier callback
  intel_pstate: Do not call wrmsrl_on_cpu() with disabled interrupts
  cpufreq: Make cpufreq_quick_get() safe to call

* pm-cpuidle:
  intel_idle: Support for Intel Xeon Phi Processor x200 Product Family
  intel_idle: prevent SKL-H boot failure when C8+C9+C10 enabled
  cpuidle: menu: Fall back to polling if next timer event is near
  cpuidle: menu: use high confidence factors only when considering polling
2016-03-25 00:57:22 +01:00
Rafael J. Wysocki 539a4c4247 cpufreq: governor: Always schedule work on the CPU running update
Modify dbs_irq_work() to always schedule the process-context work
on the current CPU which also ran the dbs_update_util_handler()
that the irq_work being handled came from.

This causes the entire frequency update handling (involving the
"ondemand" or "conservative" governors) to be carried out by the
CPU whose frequency is to be updated and reduces the overall amount
of inter-CPU noise related to cpufreq.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-03-22 23:13:36 +01:00
Rafael J. Wysocki 3bbf8fe3ae cpufreq: Always update current frequency before startig governor
Make policy->cur match the current frequency returned by the driver's
->get() callback before starting the governor in case they went out of
sync in the meantime and drop the piece of code attempting to
resync policy->cur with the real frequency of the boot CPU from
cpufreq_resume() as it serves no purpose any more (and it's racy and
super-ugly anyway).

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-03-22 23:13:36 +01:00
Rafael J. Wysocki 999f572983 cpufreq: Introduce cpufreq_update_current_freq()
Move the part of cpufreq_update_policy() that obtains the current
frequency from the driver and updates policy->cur if necessary to
a separate function, cpufreq_get_current_freq().

That should not introduce functional changes and subsequent change
set will need it.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-03-22 23:13:36 +01:00
Rafael J. Wysocki 0a300767e5 cpufreq: Introduce cpufreq_start_governor()
Starting a governor in cpufreq always follows the same pattern
involving two calls to cpufreq_governor(), one with the event
argument set to CPUFREQ_GOV_START and one with that argument set to
CPUFREQ_GOV_LIMITS.

Introduce cpufreq_start_governor() that will carry out those two
operations and make all places where governors are started use it.

That slightly modifies the behavior of cpufreq_set_policy() which
now also will go back to the old governor if the second call to
cpufreq_governor() (the one with event equal to CPUFREQ_GOV_LIMITS)
fails, but that really is how it should work in the first place.

Also cpufreq_resume() will now pring an error message if the
CPUFREQ_GOV_LIMITS call to cpufreq_governor() fails, but that
makes it follow cpufreq_add_policy_cpu() and cpufreq_offline()
in that respect.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-03-22 23:13:36 +01:00
Shilpasri G Bhat 1b0289848d cpufreq: powernv: Add sysfs attributes to show throttle stats
Create sysfs attributes to export throttle information in
/sys/devices/system/cpu/cpuX/cpufreq/throttle_stats directory. The
newly added sysfs files are as follows:

 1)/sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/turbo_stat
 2)/sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/sub-turbo_stat
 3)/sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/unthrottle
 4)/sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/powercap
 5)/sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/overtemp
 6)/sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/supply_fault
 7)/sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/overcurrent
 8)/sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/occ_reset

Detailed explanation of each attribute is added to
Documentation/ABI/testing/sysfs-devices-system-cpu

Signed-off-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-03-22 23:11:18 +01:00
Jisheng Zhang ac13b9967d cpufreq: acpi-cpufreq: make Intel/AMD MSR access, io port access static
These frequency register read/write operations' implementations for the
given processor (Intel/AMD MSR access or I/O port access) are only used
internally in acpi-cpufreq, so make them static.

Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-03-22 23:09:50 +01:00
Michael Neuling 3e5963bc34 cpufreq: powernv: Define per_cpu chip pointer to optimize hot-path
Commit 96c4726f01 "cpufreq: powernv: Remove cpu_to_chip_id() from
hot-path" introduced a 'core_to_chip_map' array to cache the chip-ids
of all cores.

Replace this with a per-CPU variable that stores the pointer to the
chip-array. This removes the linear lookup and provides a neater and
simpler solution.

Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-03-22 01:08:55 +01:00
Linus Torvalds 46e595a17d ARM: SoC driver updates for v4.6
Driver updates for ARM SoCs, these contain various things that touch
 the drivers/ directory but got merged through arm-soc for practical
 reasons:
 
 - Rockchip rk3368 gains power domain support
 - Small updates for the ARM spmi driver
 - The Atmel PMC driver saw a larger rework, touching both
   arch/arm/mach-at91 and drivers/clk/at91
 - All reset controller driver changes alway get merged through
   arm-soc, though this time the largest change is the addition
   of a MIPS pistachio reset driver
 - One bugfix for the NXP (formerly Freescale) i.MX weim bus driver
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Merge tag 'armsoc-drivers' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc

Pull ARM SoC driver updates from Arnd Bergmann:
 "Driver updates for ARM SoCs, these contain various things that touch
  the drivers/ directory but got merged through arm-soc for practical
  reasons:

   - Rockchip rk3368 gains power domain support
   - Small updates for the ARM spmi driver
   - The Atmel PMC driver saw a larger rework, touching both
     arch/arm/mach-at91 and drivers/clk/at91
   - All reset controller driver changes alway get merged through
     arm-soc, though this time the largest change is the addition of a
     MIPS pistachio reset driver
   - One bugfix for the NXP (formerly Freescale) i.MX weim bus driver"

* tag 'armsoc-drivers' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (43 commits)
  bus: imx-weim: Take the 'status' property value into account
  clk: at91: remove useless includes
  clk: at91: pmc: remove useless capacities handling
  clk: at91: pmc: drop at91_pmc_base
  usb: gadget: atmel: access the PMC using regmap
  ARM: at91: remove useless includes and function prototypes
  ARM: at91: pm: move idle functions to pm.c
  ARM: at91: pm: find and remap the pmc
  ARM: at91: pm: simply call at91_pm_init
  clk: at91: pmc: move pmc structures to C file
  clk: at91: pmc: merge at91_pmc_init in atmel_pmc_probe
  clk: at91: remove IRQ handling and use polling
  clk: at91: make use of syscon/regmap internally
  clk: at91: make use of syscon to share PMC registers in several drivers
  hwmon: (scpi) add energy meter support
  firmware: arm_scpi: add support for 64-bit sensor values
  firmware: arm_scpi: decrease Tx timeout to 20ms
  firmware: arm_scpi: fix send_message and sensor_get_value for big-endian
  reset: sti: Make reset_control_ops const
  reset: zynq: Make reset_control_ops const
  ...
2016-03-20 15:40:32 -07:00
Linus Torvalds 33b3d2e88c ARM: SoC platform updates for v4.6
Newly added support for additional SoCs:
 
 - Axis Artpec-6 SoC family
 - Allwinner A83T SoC
 - Mediatek MT7623
 - NXP i.MX6QP SoC
 - ST Microelectronics stm32f469 microcontroller
 
 New features:
 - SMP support for Mediatek mt2701
 - Big-endian support for NXP i.MX
 - DaVinci now uses the new DMA engine dma_slave_map
 - OMAP now uses the new DMA engine dma_slave_map
 - earlyprintk support for palmchip uart on mach-tango
 - delay timer support for orion
 
 Other:
 - Exynos PMU driver moved out to drivers/soc/
 - Various smaller updates for Renesas, Xilinx, PXA, AT91, OMAP, uniphier
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Merge tag 'armsoc-soc' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc

Pull ARM SoC platform updates from Arnd Bergmann:
 "Newly added support for additional SoCs:
   - Axis Artpec-6 SoC family
   - Allwinner A83T SoC
   - Mediatek MT7623
   - NXP i.MX6QP SoC
   - ST Microelectronics stm32f469 microcontroller

  New features:
   - SMP support for Mediatek mt2701
   - Big-endian support for NXP i.MX
   - DaVinci now uses the new DMA engine dma_slave_map
   - OMAP now uses the new DMA engine dma_slave_map
   - earlyprintk support for palmchip uart on mach-tango
   - delay timer support for orion

  Other:
   - Exynos PMU driver moved out to drivers/soc/
   - Various smaller updates for Renesas, Xilinx, PXA, AT91, OMAP,
     uniphier"

* tag 'armsoc-soc' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (83 commits)
  ARM: uniphier: rework SMP code to support new System Bus binding
  ARM: uniphier: add missing of_node_put()
  ARM: at91: avoid defining CONFIG_* symbols in source code
  ARM: DRA7: hwmod: Add data for eDMA tpcc, tptc0, tptc1
  ARM: imx: Make reset_control_ops const
  ARM: imx: Do L2 errata only if the L2 cache isn't enabled
  ARM: imx: select ARM_CPU_SUSPEND only for imx6
  dmaengine: pxa_dma: fix the maximum requestor line
  ARM: alpine: select the Alpine MSI controller driver
  ARM: pxa: add the number of DMA requestor lines
  dmaengine: mmp-pdma: add number of requestors
  dma: mmp_pdma: Add the #dma-requests DT property documentation
  ARM: OMAP2+: Add rtc hwmod configuration for ti81xx
  ARM: s3c24xx: Avoid warning for inb/outb
  ARM: zynq: Move early printk virtual address to vmalloc area
  ARM: DRA7: hwmod: Add custom reset handler for PCIeSS
  ARM: SAMSUNG: Remove unused register offset definition
  ARM: EXYNOS: Cleanup header files inclusion
  drivers: soc: samsung: Enable COMPILE_TEST
  MAINTAINERS: Add maintainers entry for drivers/soc/samsung
  ...
2016-03-20 14:57:08 -07:00
Richard Cochran ed72662a84 cpufreq: acpi-cpufreq: Clean up hot plug notifier callback
This driver has two issues.  First, it tries to fiddle with the hot
plugged CPU's MSR on the UP_PREPARE event, at a time when the CPU is
not yet online.  Second, the driver sets the "boost-disable" bit for a
CPU when going down, but does not clear the bit again if the CPU comes
up again due to DOWN_FAILED.

This patch fixes the issues by changing the driver to react to the
ONLINE/DOWN_FAILED events instead of UP_PREPARE.  As an added benefit,
the driver also becomes symmetric with respect to the hot plug
mechanism.

Signed-off-by: Richard Cochran <rcochran@linutronix.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-03-20 00:39:04 +01:00
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
Richard Cochran c75361c0b0 cpufreq: Make cpufreq_quick_get() safe to call
The function, cpufreq_quick_get, accesses the global 'cpufreq_driver' and
its fields without taking the associated lock, cpufreq_driver_lock.

Without the locking, nothing guarantees that 'cpufreq_driver' remains
consistent during the call.  This patch fixes the issue by taking the lock
before accessing the data structure.

Signed-off-by: Richard Cochran <rcochran@linutronix.de>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-03-18 01:49:01 +01:00
Rafael J. Wysocki 4ed3900427 Merge branch 'pm-cpufreq'
* pm-cpufreq: (94 commits)
  intel_pstate: Do not skip samples partially
  intel_pstate: Remove freq calculation from intel_pstate_calc_busy()
  intel_pstate: Move intel_pstate_calc_busy() into get_target_pstate_use_performance()
  intel_pstate: Optimize calculation for max/min_perf_adj
  intel_pstate: Remove extra conversions in pid calculation
  cpufreq: Move scheduler-related code to the sched directory
  Revert "cpufreq: postfix policy directory with the first CPU in related_cpus"
  cpufreq: Reduce cpufreq_update_util() overhead a bit
  cpufreq: Select IRQ_WORK if CPU_FREQ_GOV_COMMON is set
  cpufreq: Remove 'policy->governor_enabled'
  cpufreq: Rename __cpufreq_governor() to cpufreq_governor()
  cpufreq: Relocate handle_update() to kill its declaration
  cpufreq: governor: Drop unnecessary checks from show() and store()
  cpufreq: governor: Fix race in dbs_update_util_handler()
  cpufreq: governor: Make gov_set_update_util() static
  cpufreq: governor: Narrow down the dbs_data_mutex coverage
  cpufreq: governor: Make dbs_data_mutex static
  cpufreq: governor: Relocate definitions of tuners structures
  cpufreq: governor: Move per-CPU data to the common code
  cpufreq: governor: Make governor private data per-policy
  ...
2016-03-14 14:22:03 +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 adaf9fcd13 cpufreq: Move scheduler-related code to the sched directory
Create cpufreq.c under kernel/sched/ and move the cpufreq code
related to the scheduler to that file and to sched.h.

Redefine cpufreq_update_util() as a static inline function to avoid
function calls at its call sites in the scheduler code (as suggested
by Peter Zijlstra).

Also move the definition of struct update_util_data and declaration
of cpufreq_set_update_util_data() from include/linux/cpufreq.h to
include/linux/sched.h.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2016-03-10 20:44:47 +01:00
Viresh Kumar edd4a893e0 Revert "cpufreq: postfix policy directory with the first CPU in related_cpus"
Revert commit 3510fac454 (cpufreq: postfix policy directory with the
first CPU in related_cpus).

Earlier, the policy->kobj was added to the kobject core, before ->init()
callback was called for the cpufreq drivers. Which allowed those drivers
to add or remove, driver dependent, sysfs files/directories to the same
kobj from their ->init() and ->exit() callbacks.

That isn't possible anymore after commit 3510fac454.

Now, there is no other clean alternative that people can adopt.

Its better to revert the earlier commit to allow cpufreq drivers to
create/remove sysfs files from ->init() and ->exit() callbacks.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-03-09 21:42:45 +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 e6f036571e cpufreq: Select IRQ_WORK if CPU_FREQ_GOV_COMMON is set
Commit 0eb463be3436 (cpufreq: governor: Replace timers with utilization
update callbacks) made CPU_FREQ select IRQ_WORK, but that's not
necessary, as it is sufficient for IRQ_WORK to be selected by
CPU_FREQ_GOV_COMMON, so modify the cpufreq Kconfig to that effect.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-03-09 15:01:37 +01:00
Viresh Kumar 242aa883a6 cpufreq: Remove 'policy->governor_enabled'
The entire sequence of events (like INIT/START or STOP/EXIT) for which
cpufreq_governor() is called, is guaranteed to be protected by
policy->rwsem now.

The additional checks that were added earlier (as we were forced to drop
policy->rwsem before calling cpufreq_governor() for EXIT event), aren't
required anymore.

Over that, they weren't sufficient really. They just take care of
START/STOP events, but not INIT/EXIT and the state machine was never
maintained properly by them.

Kill the unnecessary checks and policy->governor_enabled field.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-03-09 14:41:12 +01:00
Viresh Kumar a1317e091a cpufreq: Rename __cpufreq_governor() to cpufreq_governor()
The __ at the beginning of the routine aren't really necessary at all.
Rename it to cpufreq_governor() instead.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-03-09 14:41:11 +01:00
Viresh Kumar 11eb69b984 cpufreq: Relocate handle_update() to kill its declaration
handle_update() is declared at the top of the file as its user appear
before its definition. Relocate the routine to get rid of this.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-03-09 14:41:11 +01:00
Viresh Kumar f737236b12 cpufreq: governor: Drop unnecessary checks from show() and store()
The show() and store() routines in the cpufreq-governor core don't need
to check if the struct governor_attr they want to use really provides
the callbacks they need as expected (if that's not the case, it means a
bug in the code anyway), so change them to avoid doing that.

Also change the error value to -EBUSY, if the governor is getting
removed and we aren't allowed to store any more changes.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-03-09 14:41:11 +01:00
Rafael J. Wysocki 27de348239 cpufreq: governor: Fix race in dbs_update_util_handler()
There is a scenario that may lead to undesired results in
dbs_update_util_handler().  Namely, if two CPUs sharing a policy
enter the funtion at the same time, pass the sample delay check
and then one of them is stalled until dbs_work_handler() (queued
up by the other CPU) clears the work counter, it may update the
work counter and queue up another work item prematurely.

To prevent that from happening, use the observation that the CPU
queuing up a work item in dbs_update_util_handler() updates the
last sample time.  This means that if another CPU was stalling after
passing the sample delay check and now successfully updated the work
counter as a result of the race described above, it will see the new
value of the last sample time which is different from what it used in
the sample delay check before.  If that happens, the sample delay
check passed previously is not valid any more, so the CPU should not
continue.

Fixes: f17cbb53783c (cpufreq: governor: Avoid atomic operations in hot paths)
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-03-09 14:41:10 +01:00
Rafael J. Wysocki 94ab5e030f cpufreq: governor: Make gov_set_update_util() static
The gov_set_update_util() routine is only used internally by the
common governor code and it doesn't need to be exported, so make
it static.

No functional changes.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-03-09 14:41:10 +01:00
Rafael J. Wysocki 1112e9d83e cpufreq: governor: Narrow down the dbs_data_mutex coverage
Since cpufreq_governor_dbs() is now always called with policy->rwsem
held, it cannot be executed twice in parallel for the same policy.
Thus it is not necessary to hold dbs_data_mutex around the invocations
of cpufreq_governor_start/stop/limits() from it as those functions
never modify any data that can be shared between different policies.

However, cpufreq_governor_dbs() may be executed twice in parallal
for different policies using the same gov->gdbs_data object and
dbs_data_mutex is still necessary to protect that object against
concurrent updates.

For this reason, narrow down the dbs_data_mutex locking to
cpufreq_governor_init/exit() where it is needed and rename the
mutex to gov_dbs_data_mutex to reflect its purpose.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-03-09 14:41:10 +01:00
Rafael J. Wysocki e3f5ed9393 cpufreq: governor: Make dbs_data_mutex static
That mutex is only used by cpufreq_governor_dbs() and it doesn't
need to be exported to modules, so make it static and drop the
export incantation.

No functional changes.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-03-09 14:41:09 +01:00
Rafael J. Wysocki 47ebaac1f3 cpufreq: governor: Relocate definitions of tuners structures
Move the definitions of struct od_dbs_tuners and struct cs_dbs_tuners
from the common governor header to the ondemand and conservative
governor code, respectively, as they don't need to be in the common
header any more.

No functional changes.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-03-09 14:41:09 +01:00