- Fix recent regression causing kernels built with CONFIG_PM
unset to crash on systems that support the Performance and
Energy Bias Hint (EPB) by avoiding to compile the EPB-related
code depending on CONFIG_PM when it is unset (Rafael Wysocki).
- Clean up the transition notifier invocation code in the cpufreq
core and change some users of cpufreq transition notifiers
accordingly (Viresh Kumar).
- Change MAINTAINERS to cover the schedutil governor as part of
cpufreq (Viresh Kumar).
- Simplify cpufreq_init_policy() to avoid redundant computations
(Yue Hu).
- Add explanatory comment to the cpufreq core (Rafael Wysocki).
- Introduce a new flag, GENPD_FLAG_RPM_ALWAYS_ON, to the generic
power domains (genpd) framework along with the first user of it
(Leonard Crestez).
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Merge tag 'pm-5.2-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull more power management updates from Rafael Wysocki:
"These fix a recent regression causing kernels built with CONFIG_PM
unset to crash on systems that support the Performance and Energy Bias
Hint (EPB), clean up the cpufreq core and some users of transition
notifiers and introduce a new power domain flag into the generic power
domains framework (genpd).
Specifics:
- Fix recent regression causing kernels built with CONFIG_PM unset to
crash on systems that support the Performance and Energy Bias Hint
(EPB) by avoiding to compile the EPB-related code depending on
CONFIG_PM when it is unset (Rafael Wysocki).
- Clean up the transition notifier invocation code in the cpufreq
core and change some users of cpufreq transition notifiers
accordingly (Viresh Kumar).
- Change MAINTAINERS to cover the schedutil governor as part of
cpufreq (Viresh Kumar).
- Simplify cpufreq_init_policy() to avoid redundant computations (Yue
Hu).
- Add explanatory comment to the cpufreq core (Rafael Wysocki).
- Introduce a new flag, GENPD_FLAG_RPM_ALWAYS_ON, to the generic
power domains (genpd) framework along with the first user of it
(Leonard Crestez)"
* tag 'pm-5.2-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
soc: imx: gpc: Use GENPD_FLAG_RPM_ALWAYS_ON for ERR009619
PM / Domains: Add GENPD_FLAG_RPM_ALWAYS_ON flag
cpufreq: Update MAINTAINERS to include schedutil governor
cpufreq: Don't find governor for setpolicy drivers in cpufreq_init_policy()
cpufreq: Explain the kobject_put() in cpufreq_policy_alloc()
cpufreq: Call transition notifier only once for each policy
x86: intel_epb: Take CONFIG_PM into account
In cpufreq_init_policy() we will check if there's last_governor for target
and setpolicy type. However last_governor is set only if has_target() is
true in cpufreq_offline(). That means find last_governor for setpolicy
type is pointless. Also new_policy.governor will not be used if ->setpolicy
callback is set in cpufreq_set_policy().
Moreover, there's duplicate ->setpolicy check in using default policy path.
Let's add a new helper function to avoid it. Also update comments.
Signed-off-by: Yue Hu <huyue2@yulong.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
It may not be particularly clear why the kobject_put() after
failing kobject_init_and_add() in cpufreq_policy_alloc() is not
redundant, so add a comment to explain that.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Currently, the notifiers are called once for each CPU of the policy->cpus
cpumask. It would be more optimal if the notifier can be called only
once and all the relevant information be provided to it. Out of the 23
drivers that register for the transition notifiers today, only 4 of them
do per-cpu updates and the callback for the rest can be called only once
for the policy without any impact.
This would also avoid multiple function calls to the notifier callbacks
and reduce multiple iterations of notifier core's code (which does
locking as well).
This patch adds pointer to the cpufreq policy to the struct
cpufreq_freqs, so the notifier callback has all the information
available to it with a single call. The five drivers which perform
per-cpu updates are updated to use the cpufreq policy. The freqs->cpu
field is redundant now and is removed.
Acked-by: David S. Miller <davem@davemloft.net> (sparc)
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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Merge tag 'printk-for-5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk
Pull printk updates from Petr Mladek:
- Allow state reset of printk_once() calls.
- Prevent crashes when dereferencing invalid pointers in vsprintf().
Only the first byte is checked for simplicity.
- Make vsprintf warnings consistent and inlined.
- Treewide conversion of obsolete %pf, %pF to %ps, %pF printf
modifiers.
- Some clean up of vsprintf and test_printf code.
* tag 'printk-for-5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk:
lib/vsprintf: Make function pointer_string static
vsprintf: Limit the length of inlined error messages
vsprintf: Avoid confusion between invalid address and value
vsprintf: Prevent crash when dereferencing invalid pointers
vsprintf: Consolidate handling of unknown pointer specifiers
vsprintf: Factor out %pO handler as kobject_string()
vsprintf: Factor out %pV handler as va_format()
vsprintf: Factor out %p[iI] handler as ip_addr_string()
vsprintf: Do not check address of well-known strings
vsprintf: Consistent %pK handling for kptr_restrict == 0
vsprintf: Shuffle restricted_pointer()
printk: Tie printk_once / printk_deferred_once into .data.once for reset
treewide: Switch printk users from %pf and %pF to %ps and %pS, respectively
lib/test_printf: Switch to bitmap_zalloc()
Currently the error return path from kobject_init_and_add() is not
followed by a call to kobject_put() - which means we are leaking the
kobject.
Fix it by adding a call to kobject_put() in the error path of
kobject_init_and_add().
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Tobin C. Harding <tobin@kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Currenly, __cpufreq_get() called by show_cpuinfo_cur_freq() will check
->get callback. That is needless since cpuinfo_cur_freq attribute will
not be created if ->get is not set. So let's drop it in __cpufreq_get().
Also keep this check in cpufreq_get().
Signed-off-by: Yue Hu <huyue2@yulong.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Initially, bios_limit attribute will be created if driver->bios_limit
is set in cpufreq_add_dev_interface(). So remove the redundant check
for latter show operation.
Signed-off-by: Yue Hu <huyue2@yulong.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Currently there are three calling paths for cpufreq_boost_supported() in
all as below, we can see the cpufreq_driver null check is needless since
it is already checked before.
<path1>
cpufreq_enable_boost_support()
|-> if (!cpufreq_driver)
|-> cpufreq_boost_supported()
<path2>
cpufreq_register_driver()
|-> if (!driver_data ...
|-> cpufreq_driver = driver_data
|-> cpufreq_boost_supported()
|-> remove_boost_sysfs_file()
|-> cpufreq_boost_supported()
<path3>
cpufreq_unregister_driver()
|-> if (!cpufreq_driver ...
|-> remove_boost_sysfs_file()
|-> cpufreq_boost_supported()
Signed-off-by: Yue Hu <huyue2@yulong.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
While the cpuinfo.max_freq value doesn't really matter for
intel_pstate in the active mode, in the passive mode it is used by
governors as the maximum physical frequency of the CPU and the
results of governor computations generally depend on it. Also it
is made available to user space via sysfs and it should match the
current HW configuration.
For this reason, make intel_pstate update cpuinfo.max_freq for all
CPUs if it detects a global change of turbo frequency settings from
"disable" to "enable" or the other way associated with a _PPC change
notification from the platform firmware.
Note that policy_is_inactive(), cpufreq_cpu_acquire(),
cpufreq_cpu_release(), and cpufreq_set_policy() need to be made
available to it for this purpose.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=200759
Reported-by: Gabriele Mazzotta <gabriele.mzt@gmail.com>
Tested-by: Gabriele Mazzotta <gabriele.mzt@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
It sometimes is necessary to find a cpufreq policy for a given CPU
and acquire its rwsem (for writing) immediately after that, so
introduce cpufreq_cpu_acquire() as a helper for that and the
complementary cpufreq_cpu_release().
Make cpufreq_update_policy() use the new functions.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
In some cases, the platform firmware disables or enables turbo
frequencies for all CPUs globally before triggering a _PPC change
notification for one of them. Obviously, that global change affects
all CPUs, not just the notified one, and it needs to be acted upon by
cpufreq.
The intel_pstate driver is able to detect such global changes of
the settings, but it also needs to update policy limits for all
CPUs if that happens, in particular if turbo frequencies are
enabled globally - to allow them to be used.
For this reason, introduce a new cpufreq driver callback to be
invoked on _PPC notifications, if present, instead of simply
calling cpufreq_update_policy() for the notified CPU and make
intel_pstate use it to trigger policy updates for all CPUs
in the system if global settings change.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=200759
Reported-by: Gabriele Mazzotta <gabriele.mzt@gmail.com>
Tested-by: Gabriele Mazzotta <gabriele.mzt@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Fix the formatting of the cpufreq_cpu_get() and cpufreq_cpu_put()
kerneldoc comments and rework them to be somewhat easier to follow.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The invocation of the ->setpolicy() cpufreq driver callback should
be equivalent to calling cpufreq_governor_limits(policy) for drivers
with internal governors, but in fact it isn't so, because the
temporary new_policy object is passed to it instead of the updated
policy.
That is a bit confusing, so make cpufreq_set_policy() pass the
updated policy to the driver ->setpolicy() callback.
No intentional changes of behavior.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Remove the redundant "cpufreq:" prefix from two debug messages in
cpufreq_set_policy().
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
In cpufreq_update_policy(), instead of updating new_policy.cur
separately, which is kind of confusing, because cpufreq_set_policy()
doesn't take that value into account directly anyway, make the copy
of the existing policy after calling cpufreq_update_current_freq().
No intentional changes of behavior.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Add kerneldoc comments describing cpufreq_set_policy() and
cpufreq_update_policy() as they have not been properly documented
so far and they really need to be documented.
While at it, fix white space around the cpufreq_set_policy() header.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Double NOT (!!) operation is normally done to convert a non-zero value
to 1 and keep zero as is, but that isn't the requirement in this case.
All we wanted was to make sure that only one of the two routines isn't
set, i.e. either both function pointers are set or both are unset.
This can be done with a single NOT (!) operation as well.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The cpufreq core doesn't remove the cpufreq policy anymore on CPU
offline operation, rather that happens when the CPU device gets
unregistered from the kernel. This allows faster recovery when the CPU
comes back online. This is also very useful during system wide
suspend/resume where we offline all non-boot CPUs during suspend and
then bring them back on resume.
This commit takes the same idea a step ahead to allow drivers to do
light weight tear-down and bring-up during CPU offline and online
operations.
A new set of callbacks is introduced, online/offline(). online() gets
called when the first CPU of an inactive policy is brought up and
offline() gets called when all the CPUs of a policy are offlined.
The existing init/exit() callback get called on policy
creation/destruction. They also get called instead of online/offline()
callbacks if the online/offline() callbacks aren't provided.
This also moves around some code to get executed only for the new-policy
case going forward.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
All cpufreq drivers do similar things to register as a cooling device.
Provide a cpufreq driver flag so drivers can just ask the cpufreq core
to register the cooling device on their behalf. This allows us to get
rid of duplicated code in the drivers.
In order to allow this, we add a struct thermal_cooling_device pointer
to struct cpufreq_policy so that drivers don't need to store it in a
private data structure.
Suggested-by: Stephen Boyd <swboyd@chromium.org>
Suggested-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Amit Kucheria <amit.kucheria@linaro.org>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Tested-by: Matthias Kaehlcke <mka@chromium.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The cpufreq_global_kobject is created using kobject_create_and_add()
helper, which assigns the kobj_type as dynamic_kobj_ktype and show/store
routines are set to kobj_attr_show() and kobj_attr_store().
These routines pass struct kobj_attribute as an argument to the
show/store callbacks. But all the cpufreq files created using the
cpufreq_global_kobject expect the argument to be of type struct
attribute. Things work fine currently as no one accesses the "attr"
argument. We may not see issues even if the argument is used, as struct
kobj_attribute has struct attribute as its first element and so they
will both get same address.
But this is logically incorrect and we should rather use struct
kobj_attribute instead of struct global_attr in the cpufreq core and
drivers and the show/store callbacks should take struct kobj_attribute
as argument instead.
This bug is caught using CFI CLANG builds in android kernel which
catches mismatch in function prototypes for such callbacks.
Reported-by: Donghee Han <dh.han@samsung.com>
Reported-by: Sangkyu Kim <skwith.kim@samsung.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The local variable "new_policy" hasn't been used in the error path of
cpufreq_online() since commit f9f41e3ef9 (cpufreq: Remove policy
create/remove notifiers). Don't update it in that error path.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
[ rjw: Changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
cpuinfo_cur_freq gets current CPU frequency as detected by hardware
while scaling_cur_freq last known CPU frequency. Some platforms may not
allow checking the CPU frequency of an offline CPU or the associated
resources may have been released via cpufreq_exit when the CPU gets
offlined, in which case the policy would have been invalidated already.
If we attempt to get current frequency from the hardware, it may result
in hang or crash.
For example on Juno, I see:
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000188
[0000000000000188] pgd=0000000000000000
Internal error: Oops: 96000004 [#1] PREEMPT SMP
Modules linked in:
CPU: 5 PID: 4202 Comm: cat Not tainted 4.20.0-08251-ga0f2c0318a15-dirty #87
Hardware name: ARM LTD ARM Juno Development Platform/ARM Juno Development Platform
pstate: 40000005 (nZcv daif -PAN -UAO)
pc : scmi_cpufreq_get_rate+0x34/0xb0
lr : scmi_cpufreq_get_rate+0x34/0xb0
Call trace:
scmi_cpufreq_get_rate+0x34/0xb0
__cpufreq_get+0x34/0xc0
show_cpuinfo_cur_freq+0x24/0x78
show+0x40/0x60
sysfs_kf_seq_show+0xc0/0x148
kernfs_seq_show+0x44/0x50
seq_read+0xd4/0x480
kernfs_fop_read+0x15c/0x208
__vfs_read+0x60/0x188
vfs_read+0x94/0x150
ksys_read+0x6c/0xd8
__arm64_sys_read+0x24/0x30
el0_svc_common+0x78/0x100
el0_svc_handler+0x38/0x78
el0_svc+0x8/0xc
---[ end trace 3d1024e58f77f6b2 ]---
So fix the issue by checking if the policy is invalid early in
__cpufreq_get before attempting to get the current frequency.
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
WARN_ON() already contains an unlikely(), so it's not necessary to wrap it
into another.
Signed-off-by: Igor Stoppa <igor.stoppa@huawei.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
With lockdep turned on, the following circular lock dependency problem
was reported:
[ 57.470040] ======================================================
[ 57.502900] WARNING: possible circular locking dependency detected
[ 57.535208] 4.18.0-0.rc3.1.el8+7.x86_64+debug #1 Tainted: G
[ 57.577761] ------------------------------------------------------
[ 57.609714] tuned/1505 is trying to acquire lock:
[ 57.633808] 00000000559deec5 (cpu_hotplug_lock.rw_sem){++++}, at: store+0x27/0x120
[ 57.672880]
[ 57.672880] but task is already holding lock:
[ 57.702184] 000000002136ca64 (kn->count#118){++++}, at: kernfs_fop_write+0x1d0/0x410
[ 57.742176]
[ 57.742176] which lock already depends on the new lock.
[ 57.742176]
[ 57.785220]
[ 57.785220] the existing dependency chain (in reverse order) is:
:
[ 58.932512] other info that might help us debug this:
[ 58.932512]
[ 58.973344] Chain exists of:
[ 58.973344] cpu_hotplug_lock.rw_sem --> subsys mutex#5 --> kn->count#118
[ 58.973344]
[ 59.030795] Possible unsafe locking scenario:
[ 59.030795]
[ 59.061248] CPU0 CPU1
[ 59.085377] ---- ----
[ 59.108160] lock(kn->count#118);
[ 59.124935] lock(subsys mutex#5);
[ 59.156330] lock(kn->count#118);
[ 59.186088] lock(cpu_hotplug_lock.rw_sem);
[ 59.208541]
[ 59.208541] *** DEADLOCK ***
In the cpufreq_register_driver() function, the lock sequence is:
cpus_read_lock --> kn->count
For the cpufreq sysfs store method, the lock sequence is:
kn->count --> cpus_read_lock
These sequences are actually safe as they are taking a share lock on
cpu_hotplug_lock. However, the current lockdep code doesn't check for
share locking when detecting circular lock dependency. Fixing that
could be a substantial effort.
Instead, we can work around this problem by using cpus_read_trylock()
in the store method which is much simpler. The chance of not getting
the read lock is very small. If that happens, the userspace application
that writes the sysfs file will get an error.
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
systrace used for tracing for Android systems has carried a patch for
many years in the Android tree that traces when the cpufreq limits
change. With the help of this information, systrace can know when the
policy limits change and can visually display the data. Lets add
upstream support for the same.
Signed-off-by: Ruchi Kandoi <kandoiruchi@google.com>
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Use the static SRCU initializer for `cpufreq_transition_notifier_list'.
This avoids the init_cpufreq_transition_notifier_list() initcall. Its
only purpose is to initialize the SRCU notifier once during boot and set
another variable which is used as an indicator whether the init was
perfromed before cpufreq_register_notifier() was used.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
If the policy limits are updated via cpufreq_update_policy() and
subsequently via sysfs, the limits stored in user_policy may be
set incorrectly.
For example, if both min and max are set via sysfs to the maximum
available frequency, user_policy.min and user_policy.max will also
be the maximum. If a policy notifier triggered by
cpufreq_update_policy() lowers both the min and the max at this
point, that change is not reflected by the user_policy limits, so
if the max is updated again via sysfs to the same lower value,
then user_policy.max will be lower than user_policy.min which
shouldn't happen. In particular, if one of the policy CPUs is
then taken offline and back online, cpufreq_set_policy() will
fail for it due to a failing limits check.
To prevent that from happening, initialize the min and max fields
of the new_policy object to the ones stored in user_policy that
were previously set via sysfs.
Signed-off-by: Kevin Wangtao <kevin.wangtao@hisilicon.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
[ rjw: Subject & changelog ]
Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
cpufreq_notify_transition() calls __cpufreq_notify_transition() for each
CPU of a policy. There is a lot of code in __cpufreq_notify_transition()
though which isn't required to be executed for each CPU, like checking
about disabled cpufreq or irqs, adjusting jiffies, updating cpufreq
stats and some debug print messages.
This commit merges __cpufreq_notify_transition() into
cpufreq_notify_transition() and modifies cpufreq_notify_transition() to
execute minimum amount of code for each CPU.
Also fix the kerneldoc for cpufreq_notify_transition() while at it.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The cpufreq table is already validated by the cpufreq core and none of
the users of cpufreq_generic_init() have any dependency on it to
validate the table as well.
Don't validate the cpufreq table anymore from cpufreq_generic_init().
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
By design, cpufreq drivers are responsible for calling
cpufreq_frequency_table_cpuinfo() from their ->init()
callbacks to validate the frequency table.
However, if a cpufreq driver is buggy and fails to do so properly, it
lead to unexpected behavior of the driver or the cpufreq core at a
later point in time. It would be better if the core could
validate the frequency table during driver initialization.
To that end, introduce cpufreq_table_validate_and_sort() and make
the cpufreq core call it right after invoking the ->init() callback
of the driver and destroy the cpufreq policy if the table is invalid.
For the time being the validation of the table happens twice, once
from the driver and then from the core. The individual drivers will
be updated separately to drop table validation if they don't need it
for other reasons.
The frequency table is marked "sorted" or "unsorted" by the new helper
now instead of in cpufreq_table_validate_and_show(), as it should only
be done after validating the table (which the drivers won't do going
forward).
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
[ rjw: Subject/changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Ideally the de-allocation of resources should happen in the exact
opposite order in which they were allocated. It helps maintain the code
in long term, even if nothing really breaks with incorrect ordering.
That wasn't followed in cpufreq_online() and it has some
inconsistencies. For example, the symlinks were created from within
the locked region while they are removed only after putting the locks.
Also ->exit() should have been called only after the symlinks are
removed and the lock is dropped, as that was the case when ->init()
was first called.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
[ rjw: Subject ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
cpufreq_resume can be called even without preceding cpufreq_suspend.
This can happen in following scenario:
suspend_devices_and_enter
--> dpm_suspend_start
--> dpm_prepare
--> device_prepare : this function errors out
--> dpm_suspend: this is skipped due to dpm_prepare failure
this means cpufreq_suspend is skipped over
--> goto Recover_platform, due to previous error
--> goto Resume_devices
--> dpm_resume_end
--> dpm_resume
--> cpufreq_resume
In case schedutil is used as frequency governor, cpufreq_resume will
eventually call sugov_start, which does following:
memset(sg_cpu, 0, sizeof(*sg_cpu));
....
This effectively erases function pointer for frequency update, causing
crash later on. The function pointer would have been set correctly if
subsequent cpufreq_add_update_util_hook runs successfully, but that
function returns earlier because cpufreq_suspend was not called:
if (WARN_ON(per_cpu(cpufreq_update_util_data, cpu)))
return;
The fix is to check cpufreq_suspended first, if it's false, that means
cpufreq_suspend was not called in the first place, so do not resume
cpufreq.
Signed-off-by: Bo Yan <byan@nvidia.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
[ rjw: Dropped printing a message ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
It is possible to remove a cpufreq governor module after
cpufreq_parse_governor() has returned success in
store_scaling_governor() and before cpufreq_set_policy()
acquires a reference to it, because the governor list is
not protected during that period and nothing prevents the
governor from being unregistered then.
Prevent that from happening by acquiring an extra reference
to the governor module temporarily in cpufreq_parse_governor(),
under cpufreq_governor_mutex, and dropping it in
store_scaling_governor(), when cpufreq_set_policy() returns.
Note that the second cpufreq_parse_governor() call site is fine,
because it only cares about the policy member of new_policy.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Drop a pointless return statement from cpufreq_unregister_governor().
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Pass policy pointer to cpufreq_parse_governor() instead of passing
pointers to two members of it so as to make the code slightly more
straightforward.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Drop an unnecessary local variable from cpufreq_parse_governor()
and rearrange the code in there to make it easier to follow.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Frequency-invariant accounting support based on the ratio of current
frequency and maximum supported frequency is an optional feature an arch
can implement.
Since there are cpufreq drivers (e.g. cpufreq-dt) which can be build for
different arch's a default implementation of the frequency-invariance
setter function arch_set_freq_scale() is needed.
This default implementation is an empty weak function which will be
overwritten by a strong function in case the arch provides one.
The setter function passes the cpumask of related (to the frequency
change) cpus (online and offline cpus), the (new) current frequency and
the maximum supported frequency.
Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* pm-cpufreq-sched:
cpufreq: schedutil: Always process remote callback with slow switching
cpufreq: schedutil: Don't restrict kthread to related_cpus unnecessarily
cpufreq: Return 0 from ->fast_switch() on errors
cpufreq: Simplify cpufreq_can_do_remote_dvfs()
cpufreq: Process remote callbacks from any CPU if the platform permits
sched: cpufreq: Allow remote cpufreq callbacks
cpufreq: schedutil: Use unsigned int for iowait boost
cpufreq: schedutil: Make iowait boost more energy efficient
If transition_delay_us isn't defined by the cpufreq driver, the default
value of transition delay (time after which the cpufreq governor will
try updating the frequency again) is currently calculated by multiplying
transition_latency (nsec) with LATENCY_MULTIPLIER (1000) and then
converting this time to usec. That gives the exact same value as
transition_latency, just that the time unit is usec instead of nsec.
With acpi-cpufreq for example, transition_latency is set to around 10
usec and we get transition delay as 10 ms. Which seems to be a
reasonable amount of time to reevaluate the frequency again.
But for platforms where frequency switching isn't that fast (like ARM),
the transition_latency varies from 500 usec to 3 ms, and the transition
delay becomes 500 ms to 3 seconds. Of course, that is a pretty bad
default value to start with.
We can try to come across a better formula (instead of multiplying with
LATENCY_MULTIPLIER) to solve this problem, but will that be worth it ?
This patch tries a simple approach and caps the maximum value of default
transition delay to 10 ms. Of course, userspace can still come in and
change this value anytime or individual drivers can rather provide
transition_delay_us instead.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
CPUFREQ_ENTRY_INVALID is a special symbol which is used to specify that
an entry in the cpufreq table is invalid. But using it outside of the
scope of the cpufreq table looks a bit incorrect.
We can represent an invalid frequency by writing it as 0 instead if we
need. Note that it is already done that way for the return value of the
->get() callback.
Lets do the same for ->fast_switch() and not use CPUFREQ_ENTRY_INVALID
outside of the scope of cpufreq table.
Also update the comment over cpufreq_driver_fast_switch() to clearly
mention what this returns.
None of the drivers return CPUFREQ_ENTRY_INVALID as of now from
->fast_switch() callback and so we don't need to update any of those.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
With the recent updates, CPUFREQ_ETERNAL is only used by the drivers
which don't know their transition latency but want to use dynamic
switching.
Anyway, the routine cpufreq_policy_transition_delay_us() caps the value
of transition latency to 10 ms now and that can be used safely with such
platforms.
Remove the check from cpufreq_init_governor() and allow dynamic
switching for such configurations as well.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The policy->transition_latency field is used for multiple purposes
today and its not straight forward at all. This is how it is used:
A. Set the correct transition_latency value.
B. Set it to CPUFREQ_ETERNAL because:
1. We don't want automatic dynamic switching (with
ondemand/conservative) to happen at all.
2. We don't know the transition latency.
This patch handles the B.1. case in a more readable way. A new flag for
the cpufreq drivers is added to disallow use of cpufreq governors which
have dynamic_switching flag set.
All the current cpufreq drivers which are setting transition_latency
unconditionally to CPUFREQ_ETERNAL are updated to use it. They don't
need to set transition_latency anymore.
There shouldn't be any functional change after this patch.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
There is no limitation in the ondemand or conservative governors which
disallow the transition_latency to be greater than 10 ms.
The max_transition_latency field is rather used to disallow automatic
dynamic frequency switching for platforms which didn't wanted these
governors to run.
Replace max_transition_latency with a boolean (dynamic_switching) and
check for transition_latency == CPUFREQ_ETERNAL along with that. This
makes it pretty straight forward to read/understand now.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The policy->transition_delay_us field is used only by the schedutil
governor currently, and this field describes how fast the driver wants
the cpufreq governor to change CPUs frequency. It should rather be a
common thing across all governors, as it doesn't have any schedutil
dependency here.
Create a new helper cpufreq_policy_transition_delay_us() to get the
transition delay across all governors.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
- Rework suspend-to-idle to allow it to take wakeup events signaled
by the EC into account on ACPI-based platforms in order to properly
support power button wakeup from suspend-to-idle on recent Dell
laptops (Rafael Wysocki).
That includes the core suspend-to-idle code rework, support for
the Low Power S0 _DSM interface, and support for the ACPI INT0002
Virtual GPIO device from Hans de Goede (required for USB keyboard
wakeup from suspend-to-idle to work on some machines).
- Stop trying to export the current CPU frequency via /proc/cpuinfo
on x86 as that is inaccurate and confusing (Len Brown).
- Rework the way in which the current CPU frequency is exported by
the kernel (over the cpufreq sysfs interface) on x86 systems with
the APERF and MPERF registers by always using values read from
these registers, when available, to compute the current frequency
regardless of which cpufreq driver is in use (Len Brown).
- Rework the PCI/ACPI device wakeup infrastructure to remove the
questionable and artificial distinction between "devices that
can wake up the system from sleep states" and "devices that can
generate wakeup signals in the working state" from it, which
allows the code to be simplified quite a bit (Rafael Wysocki).
- Fix the wakeup IRQ framework by making it use SRCU instead of
RCU which doesn't allow sleeping in the read-side critical
sections, but which in turn is expected to be allowed by the
IRQ bus locking infrastructure (Thomas Gleixner).
- Modify some computations in the intel_pstate driver to avoid
rounding errors resulting from them (Srinivas Pandruvada).
- Reduce the overhead of the intel_pstate driver in the HWP
(hardware-managed P-states) mode and when the "performance"
P-state selection algorithm is in use by making it avoid
registering scheduler callbacks in those cases (Len Brown).
- Rework the energy_performance_preference sysfs knob in
intel_pstate by changing the values that correspond to
different symbolic hint names used by it (Len Brown).
- Make it possible to use more than one cpuidle driver at the same
time on ARM (Daniel Lezcano).
- Make it possible to prevent the cpuidle menu governor from using
the 0 state by disabling it via sysfs (Nicholas Piggin).
- Add support for FFH (Fixed Functional Hardware) MWAIT in ACPI C1
on AMD systems (Yazen Ghannam).
- Make the CPPC cpufreq driver take the lowest nonlinear performance
information into account (Prashanth Prakash).
- Add support for hi3660 to the cpufreq-dt driver, fix the
imx6q driver and clean up the sfi, exynos5440 and intel_pstate
drivers (Colin Ian King, Krzysztof Kozlowski, Octavian Purdila,
Rafael Wysocki, Tao Wang).
- Fix a few minor issues in the generic power domains (genpd)
framework and clean it up somewhat (Krzysztof Kozlowski,
Mikko Perttunen, Viresh Kumar).
- Fix a couple of minor issues in the operating performance points
(OPP) framework and clean it up somewhat (Viresh Kumar).
- Fix a CONFIG dependency in the hibernation core and clean it up
slightly (Balbir Singh, Arvind Yadav, BaoJun Luo).
- Add rk3228 support to the rockchip-io adaptive voltage scaling
(AVS) driver (David Wu).
- Fix an incorrect bit shift operation in the RAPL power capping
driver (Adam Lessnau).
- Add support for the EPP field in the HWP (hardware managed
P-states) control register, HWP.EPP, to the x86_energy_perf_policy
tool and update msr-index.h with HWP.EPP values (Len Brown).
- Fix some minor issues in the turbostat tool (Len Brown).
- Add support for AMD family 0x17 CPUs to the cpupower tool and fix
a minor issue in it (Sherry Hurwitz).
- Assorted cleanups, mostly related to the constification of some
data structures (Arvind Yadav, Joe Perches, Kees Cook, Krzysztof
Kozlowski).
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Merge tag 'pm-4.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull power management updates from Rafael Wysocki:
"The big ticket items here are the rework of suspend-to-idle in order
to add proper support for power button wakeup from it on recent Dell
laptops and the rework of interfaces exporting the current CPU
frequency on x86.
In addition to that, support for a few new pieces of hardware is
added, the PCI/ACPI device wakeup infrastructure is simplified
significantly and the wakeup IRQ framework is fixed to unbreak the IRQ
bus locking infrastructure.
Also, there are some functional improvements for intel_pstate, tools
updates and small fixes and cleanups all over.
Specifics:
- Rework suspend-to-idle to allow it to take wakeup events signaled
by the EC into account on ACPI-based platforms in order to properly
support power button wakeup from suspend-to-idle on recent Dell
laptops (Rafael Wysocki).
That includes the core suspend-to-idle code rework, support for the
Low Power S0 _DSM interface, and support for the ACPI INT0002
Virtual GPIO device from Hans de Goede (required for USB keyboard
wakeup from suspend-to-idle to work on some machines).
- Stop trying to export the current CPU frequency via /proc/cpuinfo
on x86 as that is inaccurate and confusing (Len Brown).
- Rework the way in which the current CPU frequency is exported by
the kernel (over the cpufreq sysfs interface) on x86 systems with
the APERF and MPERF registers by always using values read from
these registers, when available, to compute the current frequency
regardless of which cpufreq driver is in use (Len Brown).
- Rework the PCI/ACPI device wakeup infrastructure to remove the
questionable and artificial distinction between "devices that can
wake up the system from sleep states" and "devices that can
generate wakeup signals in the working state" from it, which allows
the code to be simplified quite a bit (Rafael Wysocki).
- Fix the wakeup IRQ framework by making it use SRCU instead of RCU
which doesn't allow sleeping in the read-side critical sections,
but which in turn is expected to be allowed by the IRQ bus locking
infrastructure (Thomas Gleixner).
- Modify some computations in the intel_pstate driver to avoid
rounding errors resulting from them (Srinivas Pandruvada).
- Reduce the overhead of the intel_pstate driver in the HWP
(hardware-managed P-states) mode and when the "performance" P-state
selection algorithm is in use by making it avoid registering
scheduler callbacks in those cases (Len Brown).
- Rework the energy_performance_preference sysfs knob in intel_pstate
by changing the values that correspond to different symbolic hint
names used by it (Len Brown).
- Make it possible to use more than one cpuidle driver at the same
time on ARM (Daniel Lezcano).
- Make it possible to prevent the cpuidle menu governor from using
the 0 state by disabling it via sysfs (Nicholas Piggin).
- Add support for FFH (Fixed Functional Hardware) MWAIT in ACPI C1 on
AMD systems (Yazen Ghannam).
- Make the CPPC cpufreq driver take the lowest nonlinear performance
information into account (Prashanth Prakash).
- Add support for hi3660 to the cpufreq-dt driver, fix the imx6q
driver and clean up the sfi, exynos5440 and intel_pstate drivers
(Colin Ian King, Krzysztof Kozlowski, Octavian Purdila, Rafael
Wysocki, Tao Wang).
- Fix a few minor issues in the generic power domains (genpd)
framework and clean it up somewhat (Krzysztof Kozlowski, Mikko
Perttunen, Viresh Kumar).
- Fix a couple of minor issues in the operating performance points
(OPP) framework and clean it up somewhat (Viresh Kumar).
- Fix a CONFIG dependency in the hibernation core and clean it up
slightly (Balbir Singh, Arvind Yadav, BaoJun Luo).
- Add rk3228 support to the rockchip-io adaptive voltage scaling
(AVS) driver (David Wu).
- Fix an incorrect bit shift operation in the RAPL power capping
driver (Adam Lessnau).
- Add support for the EPP field in the HWP (hardware managed
P-states) control register, HWP.EPP, to the x86_energy_perf_policy
tool and update msr-index.h with HWP.EPP values (Len Brown).
- Fix some minor issues in the turbostat tool (Len Brown).
- Add support for AMD family 0x17 CPUs to the cpupower tool and fix a
minor issue in it (Sherry Hurwitz).
- Assorted cleanups, mostly related to the constification of some
data structures (Arvind Yadav, Joe Perches, Kees Cook, Krzysztof
Kozlowski)"
* tag 'pm-4.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (69 commits)
cpufreq: Update scaling_cur_freq documentation
cpufreq: intel_pstate: Clean up after performance governor changes
PM: hibernate: constify attribute_group structures.
cpuidle: menu: allow state 0 to be disabled
intel_idle: Use more common logging style
PM / Domains: Fix missing default_power_down_ok comment
PM / Domains: Fix unsafe iteration over modified list of domains
PM / Domains: Fix unsafe iteration over modified list of domain providers
PM / Domains: Fix unsafe iteration over modified list of device links
PM / Domains: Handle safely genpd_syscore_switch() call on non-genpd device
PM / Domains: Call driver's noirq callbacks
PM / core: Drop run_wake flag from struct dev_pm_info
PCI / PM: Simplify device wakeup settings code
PCI / PM: Drop pme_interrupt flag from struct pci_dev
ACPI / PM: Consolidate device wakeup settings code
ACPI / PM: Drop run_wake from struct acpi_device_wakeup_flags
PM / QoS: constify *_attribute_group.
PM / AVS: rockchip-io: add io selectors and supplies for rk3228
powercap/RAPL: prevent overridding bits outside of the mask
PM / sysfs: Constify attribute groups
...
Pull SMP hotplug updates from Thomas Gleixner:
"This update is primarily a cleanup of the CPU hotplug locking code.
The hotplug locking mechanism is an open coded RWSEM, which allows
recursive locking. The main problem with that is the recursive nature
as it evades the full lockdep coverage and hides potential deadlocks.
The rework replaces the open coded RWSEM with a percpu RWSEM and
establishes full lockdep coverage that way.
The bulk of the changes fix up recursive locking issues and address
the now fully reported potential deadlocks all over the place. Some of
these deadlocks have been observed in the RT tree, but on mainline the
probability was low enough to hide them away."
* 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (37 commits)
cpu/hotplug: Constify attribute_group structures
powerpc: Only obtain cpu_hotplug_lock if called by rtasd
ARM/hw_breakpoint: Fix possible recursive locking for arch_hw_breakpoint_init
cpu/hotplug: Remove unused check_for_tasks() function
perf/core: Don't release cred_guard_mutex if not taken
cpuhotplug: Link lock stacks for hotplug callbacks
acpi/processor: Prevent cpu hotplug deadlock
sched: Provide is_percpu_thread() helper
cpu/hotplug: Convert hotplug locking to percpu rwsem
s390: Prevent hotplug rwsem recursion
arm: Prevent hotplug rwsem recursion
arm64: Prevent cpu hotplug rwsem recursion
kprobes: Cure hotplug lock ordering issues
jump_label: Reorder hotplug lock and jump_label_lock
perf/tracing/cpuhotplug: Fix locking order
ACPI/processor: Use cpu_hotplug_disable() instead of get_online_cpus()
PCI: Replace the racy recursion prevention
PCI: Use cpu_hotplug_disable() instead of get_online_cpus()
perf/x86/intel: Drop get_online_cpus() in intel_snb_check_microcode()
x86/perf: Drop EXPORT of perf_check_microcode
...
