Commit Graph

634 Commits

Author SHA1 Message Date
Pavankumar Kondeti
55839c6999 ANDROID: cpufreq: Export cpu_frequency_limits tracepoint
Export cpu_frequency_limits trace point so that vendor modules
can register callbacks.

Bug: 182088677
Change-Id: I169c4c906ee3c760839c0757b5699f9e7b9e7646
Signed-off-by: Pavankumar Kondeti <quic_pkondeti@quicinc.com>
2021-03-08 13:26:00 +00:00
Pavankumar Kondeti
2d45001d59 ANDROID: cpufreq: Add a restricted vendor hook for freq transition
A restricted vendor hook for cpufreq transition. The hook is
invoked per policy after changing the policy->cur and passes
policy as an argument.

Bug: 181889516
Change-Id: I6f89850779fdd63e178e227c293f42b7f66fd78d
Signed-off-by: Pavankumar Kondeti <quic_pkondeti@quicinc.com>
2021-03-06 04:51:50 +05:30
Todd Kjos
efab334061 ANDROID: add vendor hooks to override show_cpufinfo_max_freq
QC value-add requires the ability to override the value displayed
by show_cpuinfo_max_freq.

Bug: 173984660
Signed-off-by: Todd Kjos <tkjos@google.com>
Change-Id: Ida11256f399f0730bc1228524b9687df3e7b8bf4
2020-11-23 21:01:12 +00:00
Greg Kroah-Hartman
3428a2f782 Merge 585e5b17b9 ("Merge tag 'fscrypt-for-linus' of git://git.kernel.org/pub/scm/fs/fscrypt/fscrypt") into android-mainline
Steps on the way to 5.10-rc4

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I8554ba37704bee02192ff6117d4909fde568fca2
2020-11-13 08:26:07 +01:00
Rafael J. Wysocki
ea9364bbad cpufreq: Add strict_target to struct cpufreq_policy
Add a new field to be set when the CPUFREQ_GOV_STRICT_TARGET flag is
set for the current governor to struct cpufreq_policy, so that the
drivers needing to check CPUFREQ_GOV_STRICT_TARGET do not have to
access the governor object during every frequency transition.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2020-11-10 18:31:17 +01:00
Rafael J. Wysocki
9a2a9ebc0a cpufreq: Introduce governor flags
A new cpufreq governor flag will be added subsequently, so replace
the bool dynamic_switching fleid in struct cpufreq_governor with a
flags field and introduce CPUFREQ_GOV_DYNAMIC_SWITCHING to set for
the "dynamic switching" governors instead of it.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2020-11-10 18:31:17 +01:00
Greg Kroah-Hartman
c13605829f Merge 65b55d4c85 ("Merge tag 'arm-soc-fixes-v5.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc") into android-mainline
Steps on the way to 5.10-rc2

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I2aae8375aa349bd63596d4bd29e50e36993c764f
2020-11-02 11:04:03 +01:00
Rafael J. Wysocki
a62f68f5ca cpufreq: Introduce cpufreq_driver_test_flags()
Add a helper function to test the flags of the cpufreq driver in use
againt a given flags mask.

In particular, this will be needed to test the
CPUFREQ_NEED_UPDATE_LIMITS cpufreq driver flag in the schedutil
governor.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-10-29 14:07:30 +01:00
Rafael J. Wysocki
1c534352f4 cpufreq: Introduce CPUFREQ_NEED_UPDATE_LIMITS driver flag
Generally, a cpufreq driver may need to update some internal upper
and lower frequency boundaries on policy max and min changes,
respectively, but currently this does not work if the target
frequency does not change along with the policy limit.

Namely, if the target frequency does not change along with the
policy min or max, the "target_freq == policy->cur" check in
__cpufreq_driver_target() prevents driver callbacks from being
invoked and they do not even have a chance to update the
corresponding internal boundary.

This particularly affects the "powersave" and "performance"
governors that always set the target frequency to one of the
policy limits and it never changes when the other limit is updated.

To allow cpufreq the drivers needing to update internal frequency
boundaries on policy limits changes to avoid this issue, introduce
a new driver flag, CPUFREQ_NEED_UPDATE_LIMITS, that (when set) will
neutralize the check mentioned above.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2020-10-27 18:47:40 +01:00
Greg Kroah-Hartman
79c83f152b Merge 1f70935f63 ("Merge tag 'armsoc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc") into android-mainline
Steps on the way to 5.10-rc1

Resolves conflicts in:
	Documentation/admin-guide/sysctl/vm.rst

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: Ic58f28718f28dae42948c935dfb0c62122fe86fc
2020-10-27 11:47:16 +01:00
Greg Kroah-Hartman
37afce95bb Merge 79db2b74aa ("Merge branch 'stable/for-linus-5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb") into android-mainline
Resolves merge issues with:
	drivers/cpufreq/cpufreq.c

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: Ic2907cf71867dab7b8e1b5fcbd4c888fc01f8c22
2020-10-25 13:05:17 +01:00
Viresh Kumar
97148d0ae5 cpufreq: Improve code around unlisted freq check
The cpufreq core checks if the frequency programmed by the bootloaders
is not listed in the freq table and programs one from the table in such
a case. This is done only if the driver has set the
CPUFREQ_NEED_INITIAL_FREQ_CHECK flag.

Currently we print two separate messages, with almost the same content,
and do this with a pr_warn() which may be a bit too much as the driver
only asked us to check this as it expected this to be the case. Lower
down the severity of the print message by switching to pr_info() instead
and print a single message only.

Reported-by: Sumit Gupta <sumitg@nvidia.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Sumit Gupta <sumitg@nvidia.com>
Tested-by: Sumit Gupta <sumitg@nvidia.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-10-16 16:19:08 +02:00
Ionela Voinescu
a20b7053b5 cpufreq,arm,arm64: restructure definitions of arch_set_freq_scale()
Compared to other arch_* functions, arch_set_freq_scale() has an atypical
weak definition that can be replaced by a strong architecture specific
implementation.

The more typical support for architectural functions involves defining
an empty stub in a header file if the symbol is not already defined in
architecture code. Some examples involve:
 - #define arch_scale_freq_capacity	topology_get_freq_scale
 - #define arch_scale_freq_invariant	topology_scale_freq_invariant
 - #define arch_scale_cpu_capacity	topology_get_cpu_scale
 - #define arch_update_cpu_topology	topology_update_cpu_topology
 - #define arch_scale_thermal_pressure	topology_get_thermal_pressure
 - #define arch_set_thermal_pressure	topology_set_thermal_pressure

Bring arch_set_freq_scale() in line with these functions by renaming it to
topology_set_freq_scale() in the arch topology driver, and by defining the
arch_set_freq_scale symbol to point to the new function for arm and arm64.

While there are other users of the arch_topology driver, this patch defines
arch_set_freq_scale for arm and arm64 only, due to their existing
definitions of arch_scale_freq_capacity. This is the getter function of the
frequency invariance scale factor and without a getter function, the
setter function - arch_set_freq_scale() has not purpose.

Signed-off-by: Ionela Voinescu <ionela.voinescu@arm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Sudeep Holla <sudeep.holla@arm.com> (BL_SWITCHER and topology parts)
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-10-08 17:17:27 +02:00
Viresh Kumar
08d8c65e84 cpufreq: Move traces and update to policy->cur to cpufreq core
The cpufreq core handles the updates to policy->cur and recording of
cpufreq trace events for all the governors except schedutil's fast
switch case.

Move that as well to cpufreq core for consistency and readability.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-10-05 15:13:43 +02:00
Viresh Kumar
96f60cddf7 cpufreq: stats: Enable stats for fast-switch as well
Now that all the blockers are gone for enabling stats in fast-switching
case, enable it.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-10-05 15:13:43 +02:00
Valentin Schneider
ecddc3a0d5 arch_topology, cpufreq: constify arch_* cpumasks
The passed cpumask arguments to arch_set_freq_scale() and
arch_freq_counters_available() are only iterated over, so reflect this
in the prototype. This also allows to pass system cpumasks like
cpu_online_mask without getting a warning.

Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Ionela Voinescu <ionela.voinescu@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-09-18 19:11:04 +02:00
Ionela Voinescu
874f635310 cpufreq: report whether cpufreq supports Frequency Invariance (FI)
Now that the update of the FI scale factor is done in cpufreq core for
selected functions - target(), target_index() and fast_switch(),
we can provide feedback to the task scheduler and architecture code
on whether cpufreq supports FI.

For this purpose provide an external function to expose whether the
cpufreq drivers support FI, by using a static key.

The logic behind the enablement of cpufreq-based invariance is as
follows:
 - cpufreq-based invariance is disabled by default
 - cpufreq-based invariance is enabled if any of the callbacks
   above is implemented while the unsupported setpolicy() is not

The cpufreq_supports_freq_invariance() function only returns whether
cpufreq is instrumented with the arch_set_freq_scale() calls that
result in support for frequency invariance. Due to the lack of knowledge
on whether the implementation of arch_set_freq_scale() actually results
in the setting of a scale factor based on cpufreq information, it is up
to the architecture code to ensure the setting and provision of the
scale factor to the scheduler.

Signed-off-by: Ionela Voinescu <ionela.voinescu@arm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-09-18 19:10:56 +02:00
Ionela Voinescu
1a0419b0db cpufreq: move invariance setter calls in cpufreq core
To properly scale its per-entity load-tracking signals, the task scheduler
needs to be given a frequency scale factor, i.e. some image of the current
frequency the CPU is running at. Currently, this scale can be computed
either by using counters (APERF/MPERF on x86, AMU on arm64), or by
piggy-backing on the frequency selection done by cpufreq.

For the latter, drivers have to explicitly set the scale factor
themselves, despite it being purely boiler-plate code: the required
information depends entirely on the kind of frequency switch callback
implemented by the driver, i.e. either of: target_index(), target(),
fast_switch() and setpolicy().

The fitness of those callbacks with regard to driving the Frequency
Invariance Engine (FIE) is studied below:

target_index()
==============
Documentation states that the chosen frequency "must be determined by
freq_table[index].frequency". It isn't clear if it *has* to be that
frequency, or if it can use that frequency value to do some computation
that ultimately leads to a different frequency selection. All drivers
go for the former, while the vexpress-spc-cpufreq has an atypical
implementation which is handled separately.

Therefore, the hook works on the assumption the core can use
freq_table[index].frequency.

target()
=======
This has been flagged as deprecated since:

  commit 9c0ebcf78f ("cpufreq: Implement light weight ->target_index() routine")

It also doesn't have that many users:

  gx-suspmod.c:439:       .target = cpufreq_gx_target,
  s3c24xx-cpufreq.c:428:  .target = s3c_cpufreq_target,
  intel_pstate.c:2528:    .target = intel_cpufreq_target,
  cppc_cpufreq.c:401:     .target = cppc_cpufreq_set_target,
  cpufreq-nforce2.c:371:  .target = nforce2_target,
  sh-cpufreq.c:163:       .target = sh_cpufreq_target,
  pcc-cpufreq.c:573:      .target = pcc_cpufreq_target,

Similarly to the path taken for target_index() calls in the cpufreq core
during a frequency change, all of the drivers above will mark the end of a
frequency change by a call to cpufreq_freq_transition_end().

Therefore, cpufreq_freq_transition_end() can be used as the location for
the arch_set_freq_scale() call to potentially inform the scheduler of the
frequency change.

This change maintains the previous functionality for the drivers that
implement the target_index() callback, while also adding support for the
few drivers that implement the deprecated target() callback.

fast_switch()
=============
This callback *has* to return the frequency that was selected.

setpolicy()
===========
This callback does not have any designated way of informing what was the
end choice. But there are only two drivers using setpolicy(), and none
of them have current FIE support:

  drivers/cpufreq/longrun.c:281:	.setpolicy	= longrun_set_policy,
  drivers/cpufreq/intel_pstate.c:2215:	.setpolicy	= intel_pstate_set_policy,

The intel_pstate is known to use counter-driven frequency invariance.

Conclusion
==========

Given that the significant majority of current FIE enabled drivers use
callbacks that lend themselves to triggering the setting of the FIE scale
factor in a generic way, move the invariance setter calls to cpufreq core.

As a result of setting the frequency scale factor in cpufreq core, after
callbacks that lend themselves to trigger it, remove this functionality
from the driver side.

To be noted that despite marking a successful frequency change, many
cpufreq drivers will consider the new frequency as the requested
frequency, although this is might not be the one granted by the hardware.

Therefore, the call to arch_set_freq_scale() is a "best effort" one, and
it is up to the architecture if the new frequency is used in the new
frequency scale factor setting (determined by the implementation of
arch_set_freq_scale()) or eventually used by the scheduler (determined
by the implementation of arch_scale_freq_capacity()). The architecture
is in a better position to decide if it has better methods to obtain
more accurate information regarding the current frequency and use that
information instead (for example, the use of counters).

Also, the implementation to arch_set_freq_scale() will now have to handle
error conditions (current frequency == 0) in order to prevent the
overhead in cpufreq core when the default arch_set_freq_scale()
implementation is used.

Signed-off-by: Ionela Voinescu <ionela.voinescu@arm.com>
Suggested-by: Valentin Schneider <valentin.schneider@arm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-09-18 19:10:42 +02:00
Greg Kroah-Hartman
f022c0602c Merge 5.9-rc3 into android-mainline
Linux 5.9-rc3

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: Ic7758bc57a7d91861657388ddd015db5c5db5480
2020-08-31 19:51:25 +02:00
Viresh Kumar
681fe68448 cpufreq: No need to verify cpufreq_driver in show_scaling_cur_freq()
"cpufreq_driver" is guaranteed to be valid here, no need to check it
here.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-08-27 12:51:25 +02:00
Greg Kroah-Hartman
df7e491a37 Merge 4b6c093e21 ("Merge tag 'block-5.9-2020-08-14' of git://git.kernel.dk/linux-block") into android-mainline
Steps on the way to 5.9-rc1

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I904678b5c31139b25fb49ee67cbacb4721a3c7bc
2020-08-17 09:19:35 +02:00
Rafael J. Wysocki
f6ebbcf08f cpufreq: intel_pstate: Implement passive mode with HWP enabled
Allow intel_pstate to work in the passive mode with HWP enabled and
make it set the HWP minimum performance limit (HWP floor) to the
P-state value given by the target frequency supplied by the cpufreq
governor, so as to prevent the HWP algorithm and the CPU scheduler
from working against each other, at least when the schedutil governor
is in use, and update the intel_pstate documentation accordingly.

Among other things, this allows utilization clamps to be taken
into account, at least to a certain extent, when intel_pstate is
in use and makes it more likely that sufficient capacity for
deadline tasks will be provided.

After this change, the resulting behavior of an HWP system with
intel_pstate in the passive mode should be close to the behavior
of the analogous non-HWP system with intel_pstate in the passive
mode, except that the HWP algorithm is generally allowed to make the
CPU run at a frequency above the floor P-state set by intel_pstate in
the entire available range of P-states, while without HWP a CPU can
run in a P-state above the requested one if the latter falls into the
range of turbo P-states (referred to as the turbo range) or if the
P-states of all CPUs in one package are coordinated with each other
at the hardware level.

[Note that in principle the HWP floor may not be taken into account
 by the processor if it falls into the turbo range, in which case the
 processor has a license to choose any P-state, either below or above
 the HWP floor, just like a non-HWP processor in the case when the
 target P-state falls into the turbo range.]

With this change applied, intel_pstate in the passive mode assumes
complete control over the HWP request MSR and concurrent changes of
that MSR (eg. via the direct MSR access interface) are overridden by
it.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Reviewed-by: Francisco Jerez <currojerez@riseup.net>
2020-08-11 17:29:45 +02:00
Greg Kroah-Hartman
a17a563d16 Merge 449dc8c970 ("Merge tag 'for-v5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/sre/linux-power-supply") into android-mainline
Merges along the way to 5.9-rc1

resolves conflicts in:
	Documentation/ABI/testing/sysfs-class-power
	drivers/power/supply/power_supply_sysfs.c
	fs/crypto/inline_crypt.c

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: Ia087834f54fb4e5269d68c3c404747ceed240701
2020-08-08 13:07:20 +02:00
Greg Kroah-Hartman
075d0ec13d Merge c0842fbc1b ("random32: move the pseudo-random 32-bit definitions to prandom.h") into android-mainline
Baby steps on the way to 5.9-rc1.

Resolves merge issues with:
	arch/arm64/boot/dts/qcom/sdm845-db845c.dts
	drivers/soc/qcom/Kconfig
	kernel/sched/cpufreq_schedutil.c

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: Ieb3344a22f9cf0d55ec5fc0daebe7602a248ab53
2020-08-07 14:27:37 +02:00
Rafael J. Wysocki
9ac1fb156a Merge branch 'cpufreq/arm/linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/vireshk/pm
Pull ARM cpufreq driver changes for v5.9-rc1 from Viresh Kumar:

"Here are the details:

- Adaptive voltage scaling (AVS) support and minor cleanups for
  brcmstb driver (Florian Fainelli and Markus Mayer).

- A new tegra driver and cleanup for the existing one (Sumit Gupta and
  Jon Hunter).

- Bandwidth level support for Qcom driver along with OPP changes (Sibi
  Sankar).

- Cleanups to sti, cpufreq-dt, ap806, CPPC drivers (Viresh Kumar, Lee
  Jones, Ivan Kokshaysky, Sven Auhagen, and Xin Hao).

- Make schedutil default governor for ARM (Valentin Schneider).

- Fix dependency issues for imx (Walter Lozano).

- Cleanup around cached_resolved_idx in cpufreq core (Viresh Kumar)."

* 'cpufreq/arm/linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/vireshk/pm:
  cpufreq: make schedutil the default for arm and arm64
  cpufreq: cached_resolved_idx can not be negative
  cpufreq: Add Tegra194 cpufreq driver
  dt-bindings: arm: Add NVIDIA Tegra194 CPU Complex binding
  cpufreq: imx: Select NVMEM_IMX_OCOTP
  cpufreq: sti-cpufreq: Fix some formatting and misspelling issues
  cpufreq: tegra186: Simplify probe return path
  cpufreq: CPPC: Reuse caps variable in few routines
  cpufreq: ap806: fix cpufreq driver needs ap cpu clk
  cpufreq: cppc: Reorder code and remove apply_hisi_workaround variable
  cpufreq: dt: fix oops on armada37xx
  cpufreq: brcmstb-avs-cpufreq: send S2_ENTER / S2_EXIT commands to AVS
  cpufreq: brcmstb-avs-cpufreq: Support polling AVS firmware
  cpufreq: brcmstb-avs-cpufreq: more flexible interface for __issue_avs_command()
  cpufreq: qcom: Disable fast switch when scaling DDR/L3
  cpufreq: qcom: Update the bandwidth levels on frequency change
  OPP: Add and export helper to set bandwidth
  cpufreq: blacklist SC7180 in cpufreq-dt-platdev
  cpufreq: blacklist SDM845 in cpufreq-dt-platdev
2020-08-04 12:44:53 +02:00
Viresh Kumar
292072c387 cpufreq: cached_resolved_idx can not be negative
It is not possible for cached_resolved_idx to be invalid here as the
cpufreq core always sets index to a positive value.

Change its type to unsigned int and fix qcom usage a bit.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2020-07-30 11:40:16 +05:30
Lee Jones
a9909c217f cpufreq: cpufreq: Demote lots of function headers unworthy of kerneldoc status
Also provide missing function parameter description for 'cpu' and 'policy'.

Fixes the following W=1 kernel build warning(s):

 drivers/cpufreq/cpufreq.c:60: warning: cannot understand function prototype: 'struct cpufreq_driver *cpufreq_driver; '
 drivers/cpufreq/cpufreq.c:90: warning: Function parameter or member 'cpufreq_policy_notifier_list' not described in 'BLOCKING_NOTIFIER_HEAD'
 drivers/cpufreq/cpufreq.c:312: warning: Function parameter or member 'val' not described in 'adjust_jiffies'
 drivers/cpufreq/cpufreq.c:312: warning: Function parameter or member 'ci' not described in 'adjust_jiffies'
 drivers/cpufreq/cpufreq.c:538: warning: Function parameter or member 'policy' not described in 'cpufreq_driver_resolve_freq'
 drivers/cpufreq/cpufreq.c:686: warning: Function parameter or member 'file_name' not described in 'show_one'
 drivers/cpufreq/cpufreq.c:686: warning: Function parameter or member 'object' not described in 'show_one'
 drivers/cpufreq/cpufreq.c:731: warning: Function parameter or member 'file_name' not described in 'store_one'
 drivers/cpufreq/cpufreq.c:731: warning: Function parameter or member 'object' not described in 'store_one'
 drivers/cpufreq/cpufreq.c:741: warning: Function parameter or member 'policy' not described in 'show_cpuinfo_cur_freq'
 drivers/cpufreq/cpufreq.c:741: warning: Function parameter or member 'buf' not described in 'show_cpuinfo_cur_freq'
 drivers/cpufreq/cpufreq.c:754: warning: Function parameter or member 'policy' not described in 'show_scaling_governor'
 drivers/cpufreq/cpufreq.c:754: warning: Function parameter or member 'buf' not described in 'show_scaling_governor'
 drivers/cpufreq/cpufreq.c:770: warning: Function parameter or member 'policy' not described in 'store_scaling_governor'
 drivers/cpufreq/cpufreq.c:770: warning: Function parameter or member 'buf' not described in 'store_scaling_governor'
 drivers/cpufreq/cpufreq.c:770: warning: Function parameter or member 'count' not described in 'store_scaling_governor'
 drivers/cpufreq/cpufreq.c:806: warning: Function parameter or member 'policy' not described in 'show_scaling_driver'
 drivers/cpufreq/cpufreq.c:806: warning: Function parameter or member 'buf' not described in 'show_scaling_driver'
 drivers/cpufreq/cpufreq.c:815: warning: Function parameter or member 'policy' not described in 'show_scaling_available_governors'
 drivers/cpufreq/cpufreq.c:815: warning: Function parameter or member 'buf' not described in 'show_scaling_available_governors'
 drivers/cpufreq/cpufreq.c:859: warning: Function parameter or member 'policy' not described in 'show_related_cpus'
 drivers/cpufreq/cpufreq.c:859: warning: Function parameter or member 'buf' not described in 'show_related_cpus'
 drivers/cpufreq/cpufreq.c:867: warning: Function parameter or member 'policy' not described in 'show_affected_cpus'
 drivers/cpufreq/cpufreq.c:867: warning: Function parameter or member 'buf' not described in 'show_affected_cpus'
 drivers/cpufreq/cpufreq.c:901: warning: Function parameter or member 'policy' not described in 'show_bios_limit'
 drivers/cpufreq/cpufreq.c:901: warning: Function parameter or member 'buf' not described in 'show_bios_limit'
 drivers/cpufreq/cpufreq.c:1625: warning: Function parameter or member 'dev' not described in 'cpufreq_remove_dev'
 drivers/cpufreq/cpufreq.c:1625: warning: Function parameter or member 'sif' not described in 'cpufreq_remove_dev'
 drivers/cpufreq/cpufreq.c:2380: warning: Function parameter or member 'cpu' not described in 'cpufreq_get_policy'
 drivers/cpufreq/cpufreq.c:2771: warning: Function parameter or member 'driver' not described in 'cpufreq_unregister_driver'

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-07-15 15:17:06 +02:00
Viresh Kumar
3a7e4fbbfd cpufreq: Remove the weakly defined cpufreq_default_governor()
The default cpufreq governor is chosen with the help of a "choice"
option in the Kconfig which will always end up selecting one of
the governors and so the weakly defined definition of
cpufreq_default_governor() will never get called.

Moreover, this makes us skip the checking of the return value of
that routine as it will always be non NULL.

If the Kconfig option changes in future, then we will start getting
a link error instead (and it won't go unnoticed as in the case of the
weak definition).

Suggested-by: Quentin Perret <qperret@google.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-07-02 13:03:31 +02:00
Quentin Perret
8412b4563e cpufreq: Specify default governor on command line
Currently, the only way to specify the default CPUfreq governor is
via Kconfig options, which suits users who can build the kernel
themselves perfectly.

However, for those who use a distro-like kernel (such as Android,
with the Generic Kernel Image project), the only way to use a
non-default governor is to boot to userspace, and to then switch
using the sysfs interface. Being able to specify the default governor
on the command line, like is the case for cpuidle, would allow those
users to specify their governor of choice earlier on, and to simplify
the userspace boot procedure slighlty.

To support this use-case, add a kernel command line parameter
allowing the default governor for CPUfreq to be specified, which
takes precedence over the built-in default.

This implementation has one notable limitation: the default governor
must be registered before the driver. This is solved for builtin
governors and drivers using appropriate *_initcall() functions. And
in the modular case, this must be reflected as a constraint on the
module loading order.

Signed-off-by: Quentin Perret <qperret@google.com>
[ Viresh: Converted 'default_governor' to a string and parsing it only
	  at initcall level, and several updates to
	  cpufreq_init_policy(). ]
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
[ rjw: Changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-07-02 13:03:30 +02:00
Viresh Kumar
8cc46ae565 cpufreq: Fix locking issues with governors
The locking around governors handling isn't adequate currently.

The list of governors should never be traversed without the locking
in place. Also governor modules must not be removed while the code
in them is still in use.

Reported-by: Quentin Perret <qperret@google.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: All applicable <stable@vger.kernel.org>
[ rjw: Changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-07-02 13:02:55 +02:00
Greg Kroah-Hartman
a33191d441 Merge 5.8-rc1 into android-mainline
Linux 5.8-rc1

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I00f2168bc9b6fd8e48c7c0776088d2c6cb8e1629
2020-06-25 14:25:32 +02:00
Greg Kroah-Hartman
48ef1614d0 Merge faa392181a ("Merge tag 'drm-next-2020-06-02' of git://anongit.freedesktop.org/drm/drm") into android-mainline
Tiny merge resolutions along the way to 5.8-rc1.

Change-Id: I0036e22af4e398b0bb3b9855ff90d60b9c0227ee
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2020-06-12 15:13:27 +02:00
Quentin Perret
bdfa61448f ANDROID: sched: Allow EAS without schedutil
This effectively reverts 531b5c9f5c ("sched/topology: Make Energy
Aware Scheduling depend on schedutil"), and updates the documentation
accordingly.

In the context of GKI 2.0, some partners need to use a custom cpufreq
govenor, but would like to keep EAS enabled.

Remove the hard dependency between them.

Bug: 157580690
Signed-off-by: Quentin Perret <qperret@google.com>
Change-Id: Ied1c5aba6b692e26776b3e2c050780a67cc5bae1
2020-06-05 16:35:46 +00:00
Xiongfeng Wang
cf6fada715 cpufreq: change '.set_boost' to act on one policy
Macro 'for_each_active_policy()' is defined internally. To avoid some
cpufreq driver needing this macro to iterate over all the policies in
'.set_boost' callback, we redefine '.set_boost' to act on only one
policy and pass the policy as an argument.

'cpufreq_boost_trigger_state()' iterates over all the policies to set
boost for the system.

This is preparation for adding SW BOOST support for CPPC.

To protect Boost enable/disable by sysfs from CPU online/offline,
add 'cpu_hotplug_lock' before calling '.set_boost' for each CPU.

Also move the lock from 'set_boost()' to 'store_cpb()' in
acpi_cpufreq.

Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Suggested-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
[ rjw: Subject & changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-06-05 14:20:02 +02:00
Rafael J. Wysocki
552abb884e cpufreq: Fix up cpufreq_boost_set_sw()
After commit 18c49926c4 ("cpufreq: Add QoS requests for userspace
constraints") the return value of freq_qos_update_request(), that can
be 1, passed by cpufreq_boost_set_sw() to its caller sometimes
confuses the latter, which only expects to see 0 or negative error
codes, so notice that cpufreq_boost_set_sw() can return an error code
(which should not be -EINVAL for that matter) as soon as the first
policy without a frequency table is found (because either all policies
have a frequency table or none of them have it) and rework it to meet
its caller's expectations.

Fixes: 18c49926c4 ("cpufreq: Add QoS requests for userspace constraints")
Reported-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Reported-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: 5.3+ <stable@vger.kernel.org> # 5.3+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-05-18 13:01:28 +02:00
Quentin Perret
c65b550185 Revert "ANDROID: cpufreq: arch_topology: implement max frequency capping"
This reverts commit 0cfe39fe40.

Upstream has an equivalent feature now, drop the Android-specific
version.

Bug: 120440300
Signed-off-by: Quentin Perret <qperret@google.com>
Change-Id: Id1b2ad9249fb3441082cad34872d237b32b19b82
2020-04-07 07:12:50 +00:00
Greg Kroah-Hartman
6aea7b7129 Merge 1a323ea535 ("x86: get rid of 'errret' argument to __get_user_xyz() macross") into android-mainline
In a quest to divide up the 5.7-rc1 merge chunks into reviewable pieces.

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I2e5960415348c06e8f10e10cbefb3ee5c3745e73
2020-04-04 12:17:50 +02:00
Linus Torvalds
3cd86a58f7 Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull arm64 updates from Catalin Marinas:
 "The bulk is in-kernel pointer authentication, activity monitors and
  lots of asm symbol annotations. I also queued the sys_mremap() patch
  commenting the asymmetry in the address untagging.

  Summary:

   - In-kernel Pointer Authentication support (previously only offered
     to user space).

   - ARM Activity Monitors (AMU) extension support allowing better CPU
     utilisation numbers for the scheduler (frequency invariance).

   - Memory hot-remove support for arm64.

   - Lots of asm annotations (SYM_*) in preparation for the in-kernel
     Branch Target Identification (BTI) support.

   - arm64 perf updates: ARMv8.5-PMU 64-bit counters, refactoring the
     PMU init callbacks, support for new DT compatibles.

   - IPv6 header checksum optimisation.

   - Fixes: SDEI (software delegated exception interface) double-lock on
     hibernate with shared events.

   - Minor clean-ups and refactoring: cpu_ops accessor,
     cpu_do_switch_mm() converted to C, cpufeature finalisation helper.

   - sys_mremap() comment explaining the asymmetric address untagging
     behaviour"

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (81 commits)
  mm/mremap: Add comment explaining the untagging behaviour of mremap()
  arm64: head: Convert install_el2_stub to SYM_INNER_LABEL
  arm64: Introduce get_cpu_ops() helper function
  arm64: Rename cpu_read_ops() to init_cpu_ops()
  arm64: Declare ACPI parking protocol CPU operation if needed
  arm64: move kimage_vaddr to .rodata
  arm64: use mov_q instead of literal ldr
  arm64: Kconfig: verify binutils support for ARM64_PTR_AUTH
  lkdtm: arm64: test kernel pointer authentication
  arm64: compile the kernel with ptrauth return address signing
  kconfig: Add support for 'as-option'
  arm64: suspend: restore the kernel ptrauth keys
  arm64: __show_regs: strip PAC from lr in printk
  arm64: unwind: strip PAC from kernel addresses
  arm64: mask PAC bits of __builtin_return_address
  arm64: initialize ptrauth keys for kernel booting task
  arm64: initialize and switch ptrauth kernel keys
  arm64: enable ptrauth earlier
  arm64: cpufeature: handle conflicts based on capability
  arm64: cpufeature: Move cpu capability helpers inside C file
  ...
2020-03-31 10:05:01 -07:00
Ionela Voinescu
bbce8eaa60 cpufreq: add function to get the hardware max frequency
Add weak function to return the hardware maximum frequency of a CPU,
with the default implementation returning cpuinfo.max_freq, which is
the best information we can generically get from the cpufreq framework.

The default can be overwritten by a strong function in platforms
that want to provide an alternative implementation, with more accurate
information, obtained either from hardware or firmware.

Signed-off-by: Ionela Voinescu <ionela.voinescu@arm.com>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-03-06 16:02:50 +00:00
Greg Kroah-Hartman
f4bdd2d3e4 Merge 5.6-rc4 into android-mainline
Linux 5.6-rc4

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I578d32be8e67dcc83c260e5e6bf63c493d40735d
2020-03-02 11:56:25 +01:00
Rafael J. Wysocki
f5739cb0b5 cpufreq: Fix policy initialization for internal governor drivers
Before commit 1e4f63aecb ("cpufreq: Avoid creating excessively
large stack frames") the initial value of the policy field in struct
cpufreq_policy set by the driver's ->init() callback was implicitly
passed from cpufreq_init_policy() to cpufreq_set_policy() if the
default governor was neither "performance" nor "powersave".  After
that commit, however, cpufreq_init_policy() must take that case into
consideration explicitly and handle it as appropriate, so make that
happen.

Fixes: 1e4f63aecb ("cpufreq: Avoid creating excessively large stack frames")
Link: https://lore.kernel.org/linux-pm/39fb762880c27da110086741315ca8b111d781cd.camel@gmail.com/
Reported-by: Artem Bityutskiy <dedekind1@gmail.com>
Cc: 5.4+ <stable@vger.kernel.org> # 5.4+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2020-02-27 08:57:48 +01:00
Greg Kroah-Hartman
57ba579f7f Merge 5.6-rc2 into android-mainline
Linux 5.6-rc2

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: Ia8f34ab9a6f8a2a3b8b759da8d48ab035ac1cf83
2020-02-19 08:28:52 +01:00
Greg Kroah-Hartman
1f77f18bb8 Merge a45ad71e89 ("Merge tag 'rproc-v5.6' of git://git.kernel.org/pub/scm/linux/kernel/git/andersson/remoteproc") into android-mainline
Another "small" merge point to handle conflicts in a sane way.

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I5dc2f5f11275b29f3c9b5b8d4dd59864ceb6faf9
2020-02-08 13:32:37 +01:00
Yangtao Li
183edb20e6 cpufreq: Make cpufreq_global_kobject static
The cpufreq_global_kobject is only used internally by cpufreq.c
after commit 2361be2366 ("cpufreq: Don't create empty
/sys/devices/system/cpu/cpufreq directory").

Make it static.

Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
[ rjw: Add empty line after cpufreq_global_kobject definition ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-02-03 16:56:48 +01:00
Rafael J. Wysocki
1e4f63aecb cpufreq: Avoid creating excessively large stack frames
In the process of modifying a cpufreq policy, the cpufreq core makes
a copy of it including all of the internals which is stored on the
CPU stack.  Because struct cpufreq_policy is relatively large, this
may cause the size of the stack frame to exceed the 2 KB limit and
so the GCC complains when -Wframe-larger-than= is used.

In fact, it is not necessary to copy the entire policy structure
in order to modify it, however.

First, because cpufreq_set_policy() obtains the min and max policy
limits from frequency QoS now, it is not necessary to pass the limits
to it from the callers.  The only things that need to be passed to it
from there are the new governor pointer or (if there is a built-in
governor in the driver) the "policy" value representing the governor
choice.  They both can be passed as individual arguments, though, so
make cpufreq_set_policy() take them this way and rework its callers
accordingly.  This avoids making copies of cpufreq policies in the
callers of cpufreq_set_policy().

Second, cpufreq_set_policy() still needs to pass the new policy
data to the ->verify() callback of the cpufreq driver whose task
is to sanitize the min and max policy limits.  It still does not
need to make a full copy of struct cpufreq_policy for this purpose,
but it needs to pass a few items from it to the driver in case they
are needed (different drivers have different needs in that respect
and all of them have to be covered).  For this reason, introduce
struct cpufreq_policy_data to hold copies of the members of
struct cpufreq_policy used by the existing ->verify() driver
callbacks and pass a pointer to a temporary structure of that
type to ->verify() (instead of passing a pointer to full struct
cpufreq_policy to it).

While at it, notice that intel_pstate and longrun don't really need
to verify the "policy" value in struct cpufreq_policy, so drop those
check from them to avoid copying "policy" into struct
cpufreq_policy_data (which allows it to be slightly smaller).

Also while at it fix up white space in a couple of places and make
cpufreq_set_policy() static (as it can be so).

Fixes: 3000ce3c52 ("cpufreq: Use per-policy frequency QoS")
Link: https://lore.kernel.org/linux-pm/CAMuHMdX6-jb1W8uC2_237m8ctCpsnGp=JCxqt8pCWVqNXHmkVg@mail.gmail.com
Reported-by: kbuild test robot <lkp@intel.com>
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: 5.4+ <stable@vger.kernel.org> # 5.4+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2020-01-27 10:33:33 +01:00
Greg Kroah-Hartman
d3a196a371 Merge 5.5-rc1 into android-mainline
Linux 5.5-rc1

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I6f952ebdd40746115165a2f99bab340482f5c237
2019-12-09 12:12:00 +01:00
Linus Torvalds
9e7a03233e Merge tag 'pm-5.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull power management updates from Rafael Wysocki:
 "These include cpuidle changes to use nanoseconds (instead of
  microseconds) as the unit of time and to simplify checks for disabled
  idle states in the idle loop, some cpuidle fixes and governor updates,
  assorted cpufreq updates (driver updates mostly and a few core fixes
  and cleanups), devfreq updates (dominated by the tegra30 driver
  changes), new CPU IDs for the RAPL power capping driver, relatively
  minor updates of the generic power domains (genpd) and operation
  performance points (OPP) frameworks, and assorted fixes and cleanups.

  There are also two maintainer information updates: Chanwoo Choi will
  be maintaining the devfreq subsystem going forward and Todd Brandt is
  going to maintain the pm-graph utility (created by him).

  Specifics:

   - Use nanoseconds (instead of microseconds) as the unit of time in
     the cpuidle core and simplify checks for disabled idle states in
     the idle loop (Rafael Wysocki)

   - Fix and clean up the teo cpuidle governor (Rafael Wysocki)

   - Fix the cpuidle registration error code path (Zhenzhong Duan)

   - Avoid excessive vmexits in the ACPI cpuidle driver (Yin Fengwei)

   - Extend the idle injection infrastructure to be able to measure the
     requested duration in nanoseconds and to allow an exit latency
     limit for idle states to be specified (Daniel Lezcano)

   - Fix cpufreq driver registration and clarify a comment in the
     cpufreq core (Viresh Kumar)

   - Add NULL checks to the show() and store() methods of sysfs
     attributes exposed by cpufreq (Kai Shen)

   - Update cpufreq drivers:
      * Fix for a plain int as pointer warning from sparse in
        intel_pstate (Jamal Shareef)
      * Fix for a hardcoded number of CPUs and stack bloat in the
        powernv driver (John Hubbard)
      * Updates to the ti-cpufreq driver and DT files to support new
        platforms and migrate bindings from opp-v1 to opp-v2 (Adam Ford,
        H. Nikolaus Schaller)
      * Merging of the arm_big_little and vexpress-spc drivers and
        related cleanup (Sudeep Holla)
      * Fix for imx's default speed grade value (Anson Huang)
      * Minor cleanup of the s3c64xx driver (Nathan Chancellor)
      * CPU speed bin detection fix for sun50i (Ondrej Jirman)

   - Appoint Chanwoo Choi as the new devfreq maintainer.

   - Update the devfreq core:
      * Check NULL governor in available_governors_show sysfs to prevent
        showing wrong governor information and fix a race condition
        between devfreq_update_status() and trans_stat_show() (Leonard
        Crestez)
      * Add new 'interrupt-driven' flag for devfreq governors to allow
        interrupt-driven governors to prevent the devfreq core from
        polling devices for status (Dmitry Osipenko)
      * Improve an error message in devfreq_add_device() (Matthias
        Kaehlcke)

   - Update devfreq drivers:
      * tegra30 driver fixes and cleanups (Dmitry Osipenko)
      * Removal of unused property from dt-binding documentation for the
        exynos-bus driver (Kamil Konieczny)
      * exynos-ppmu cleanup and DT bindings update (Lukasz Luba, Marek
        Szyprowski)

   - Add new CPU IDs for CometLake Mobile and Desktop to the Intel RAPL
     power capping driver (Zhang Rui)

   - Allow device initialization in the generic power domains (genpd)
     framework to be more straightforward and clean it up (Ulf Hansson)

   - Add support for adjusting OPP voltages at run time to the OPP
     framework (Stephen Boyd)

   - Avoid freeing memory that has never been allocated in the
     hibernation core (Andy Whitcroft)

   - Clean up function headers in a header file and coding style in the
     wakeup IRQs handling code (Ulf Hansson, Xiaofei Tan)

   - Clean up the SmartReflex adaptive voltage scaling (AVS) driver for
     ARM (Ben Dooks, Geert Uytterhoeven)

   - Wrap power management documentation to fit in 80 columns (Bjorn
     Helgaas)

   - Add pm-graph utility entry to MAINTAINERS (Todd Brandt)

   - Update the cpupower utility:
      * Fix the handling of set and info subcommands (Abhishek Goel)
      * Fix build warnings (Nathan Chancellor)
      * Improve mperf_monitor handling (Janakarajan Natarajan)"

* tag 'pm-5.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (83 commits)
  PM: Wrap documentation to fit in 80 columns
  cpuidle: Pass exit latency limit to cpuidle_use_deepest_state()
  cpuidle: Allow idle injection to apply exit latency limit
  cpuidle: Introduce cpuidle_driver_state_disabled() for driver quirks
  cpuidle: teo: Avoid code duplication in conditionals
  cpufreq: Register drivers only after CPU devices have been registered
  cpuidle: teo: Avoid using "early hits" incorrectly
  cpuidle: teo: Exclude cpuidle overhead from computations
  PM / Domains: Convert to dev_to_genpd_safe() in genpd_syscore_switch()
  mmc: tmio: Avoid boilerplate code in ->runtime_suspend()
  PM / Domains: Implement the ->start() callback for genpd
  PM / Domains: Introduce dev_pm_domain_start()
  ARM: OMAP2+: SmartReflex: add omap_sr_pdata definition
  PM / wakeirq: remove unnecessary parentheses
  power: avs: smartreflex: Remove superfluous cast in debugfs_create_file() call
  cpuidle: Use nanoseconds as the unit of time
  PM / OPP: Support adjusting OPP voltages at runtime
  PM / core: Clean up some function headers in power.h
  cpufreq: Add NULL checks to show() and store() methods of cpufreq
  cpufreq: intel_pstate: Fix plain int as pointer warning from sparse
  ...
2019-11-26 19:06:44 -08:00
Frederic Weisbecker
5720821ba1 cpufreq: Use vtime aware kcpustat accessors for user time
We can now safely read user and guest kcpustat fields on nohz_full CPUs.
Use the appropriate accessors.

Reported-by: Yauheni Kaliuta <yauheni.kaliuta@redhat.com>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wanpeng Li <wanpengli@tencent.com>
Link: https://lkml.kernel.org/r/20191121024430.19938-5-frederic@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-11-21 07:33:25 +01:00
Viresh Kumar
46770be0cf cpufreq: Register drivers only after CPU devices have been registered
The cpufreq core heavily depends on the availability of the struct
device for CPUs and if they aren't available at the time cpufreq driver
is registered, we will never succeed in making cpufreq work.

This happens due to following sequence of events:

- cpufreq_register_driver()
  - subsys_interface_register()
  - return 0; //successful registration of driver

... at a later point of time

- register_cpu();
  - device_register();
    - bus_probe_device();
      - sif->add_dev();
	- cpufreq_add_dev();
	  - get_cpu_device(); //FAILS
  - per_cpu(cpu_sys_devices, num) = &cpu->dev; //used by get_cpu_device()
  - return 0; //CPU registered successfully

Because the per-cpu variable cpu_sys_devices is set only after the CPU
device is regsitered, cpufreq will never be able to get it when
cpufreq_add_dev() is called.

This patch avoids this failure by making sure device structure of at
least CPU0 is available when the cpufreq driver is registered, else
return -EPROBE_DEFER.

Reported-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Co-developed-by: Amit Kucheria <amit.kucheria@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Tested-by: Amit Kucheria <amit.kucheria@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-11-14 09:37:14 +01:00
Ingo Molnar
6d5a763c30 Merge tag 'v5.4-rc7' into sched/core, to pick up fixes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-11-11 08:34:59 +01:00