[ Upstream commit b8f85833c05730d631576008daaa34096bc7f3ce ]
The exit() callback is optional and shouldn't be called without checking
a valid pointer first.
Also, we must clear freq_table pointer even if the exit() callback isn't
present.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Fixes: 91a12e91dc ("cpufreq: Allow light-weight tear down and bring up of CPUs")
Fixes: f339f35417 ("cpufreq: Rearrange locking in cpufreq_remove_dev()")
Reported-by: Lizhe <sensor1010@163.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit c4d61a529db788d2e52654f5b02c8d1de4952c5b ]
Offlining a CPU and bringing it back online is a common operation and it
happens frequently during system suspend/resume, where the non-boot CPUs
are hotplugged out during suspend and brought back at resume.
The cpufreq core already tries to make this path as fast as possible as
the changes are only temporary in nature and full cleanup of resources
isn't required in this case. For example the drivers can implement
online()/offline() callbacks to avoid a lot of tear down of resources.
On similar lines, there is no need to unregister the cpufreq cooling
device during suspend / resume, but only while the policy is getting
removed.
Moreover, unregistering the cpufreq cooling device is resulting in an
unwanted outcome, where the system suspend is eventually aborted in the
process. Currently, during system suspend the cpufreq core unregisters
the cooling device, which in turn removes a kobject using device_del()
and that generates a notification to the userspace via uevent broadcast.
This causes system suspend to abort in some setups.
This was also earlier reported (indirectly) by Roman [1]. Maybe there is
another way around to fixing that problem properly, but this change
makes sense anyways.
Move the registering and unregistering of the cooling device to policy
creation and removal times onlyy.
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218521
Reported-by: Manaf Meethalavalappu Pallikunhi <quic_manafm@quicinc.com>
Reported-by: Roman Stratiienko <r.stratiienko@gmail.com>
Link: https://patchwork.kernel.org/project/linux-pm/patch/20220710164026.541466-1-r.stratiienko@gmail.com/ [1]
Tested-by: Manaf Meethalavalappu Pallikunhi <quic_manafm@quicinc.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Dhruva Gole <d-gole@ti.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit f37a4d6b4a2c77414e8b9d25dd5ee31537ce9b00 ]
In the existing code, per-policy flags don't have any impact i.e.
if cpufreq_driver boost is enabled and boost is disabled for one or
more of the policies, the cpufreq driver will behave as if boost is
enabled.
Fix this by incorporating per-policy boost flag in the policy->max
computation used in cpufreq_frequency_table_cpuinfo and setting the
default per-policy boost to mirror the cpufreq_driver boost flag.
Fixes: 218a06a79d ("cpufreq: Support per-policy performance boost")
Reported-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Dhruva Gole <d-gole@ti.com>
Signed-off-by: Sibi Sankar <quic_sibis@quicinc.com>
Tested-by:Yipeng Zou <zouyipeng@huawei.com> <mailto:zouyipeng@huawei.com>
Reviewed-by: Yipeng Zou <zouyipeng@huawei.com> <mailto:zouyipeng@huawei.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
The boost control currently applies to the whole system. However, users
may prefer to boost a subset of cores in order to provide prioritized
performance to workloads running on the boosted cores.
Enable per-policy boost by adding a 'boost' sysfs interface under each
policy path. This can be found at:
/sys/devices/system/cpu/cpufreq/policy<*>/boost
Same to the global boost switch, writing 1/0 to the per-policy 'boost'
enables/disables boost on a cpufreq policy respectively.
The user view of global and per-policy boost controls should be:
1. Enabling global boost initially enables boost on all policies, and
per-policy boost can then be enabled or disabled individually, given that
the platform does support so.
2. Disabling global boost makes the per-policy boost interface illegal.
Signed-off-by: Jie Zhan <zhanjie9@hisilicon.com>
Reviewed-by: Wei Xu <xuwei5@hisilicon.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The field 'transition_task' of policy structure is used to track the
task which is performing the frequency transition. Using this field to
print a warning once detect a case where the same task is calling
_begin() again before completing the preivous frequency transition via
the _end().
However, there is a potential race condition in _end() and _begin() APIs
while updating the field 'transition_task' of policy, the scenario is
depicted below:
Task A Task B
/* 1st freq transition */
Invoke _begin() {
...
...
}
/* 2nd freq transition */
Invoke _begin() {
... //waiting for A to
... //clear
... //transition_ongoing
... //in _end() for
... //the 1st transition
|
Change the frequency |
|
Invoke _end() { |
... |
... |
transition_ongoing = false; V
transition_ongoing = true;
transition_task = current;
transition_task = NULL;
... //A overwrites the task
... //performing the transition
... //result in error warning.
}
To fix this race condition, the transition_lock of policy structure is
now acquired before updating policy structure in _end() API. Which ensure
that only one task can update the 'transition_task' field at a time.
Link: https://lore.kernel.org/all/b3c61d8a-d52d-3136-fbf0-d1de9f1ba411@huawei.com/
Fixes: ca654dc3a9 ("cpufreq: Catch double invocations of cpufreq_freq_transition_begin/end")
Signed-off-by: Liao Chang <liaochang1@huawei.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The pointer value of policy and driver structure are currently printed
in the error messages of cpufreq_resume(), this is not recommended and
helpful.
In order to be consistent with the error message in cpufreq_suspend()
and easier to understand, print the name of driver strcture and the
manage CPU of policy structure individually in the error messages of
cpufreq_resume().
Link: https://lore.kernel.org/all/b7be717c-41d8-bbbf-3e97-3799948ab757@huawei.com
Signed-off-by: Liao Chang <liaochang1@huawei.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
When a cpufreq_policy is allocated, the cpus, related_cpus and real_cpus
of policy are still unset. Therefore, it is preferable to print the
passed 'cpu' parameter instead of a empty 'cpus' cpumask in error
message when registering MIN/MAX QoS notifier fails.
Signed-off-by: Liao Chang <liaochang1@huawei.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
If fast_switch_possible flag is set by the scaling driver, the governor
is free to select fast_switch function even if adjust_perf is set. Some
scaling drivers which use adjust_perf don't set fast_switch thinking
that the governor would never fall back to fast_switch. But the governor
can fall back to fast_switch even in runtime if frequency invariance is
disabled due to some reason. This could crash the kernel if the driver
didn't set the fast_switch function pointer.
Therefore, fail driver registration if it has adjust_perf without
fast_switch.
Suggested-by: Rafael J. Wysocki <rafael@kernel.org>
Suggested-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Wyes Karny <wyes.karny@amd.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Here is the large set of driver core changes for 6.4-rc1.
Once again, a busy development cycle, with lots of changes happening in
the driver core in the quest to be able to move "struct bus" and "struct
class" into read-only memory, a task now complete with these changes.
This will make the future rust interactions with the driver core more
"provably correct" as well as providing more obvious lifetime rules for
all busses and classes in the kernel.
The changes required for this did touch many individual classes and
busses as many callbacks were changed to take const * parameters
instead. All of these changes have been submitted to the various
subsystem maintainers, giving them plenty of time to review, and most of
them actually did so.
Other than those changes, included in here are a small set of other
things:
- kobject logging improvements
- cacheinfo improvements and updates
- obligatory fw_devlink updates and fixes
- documentation updates
- device property cleanups and const * changes
- firwmare loader dependency fixes.
All of these have been in linux-next for a while with no reported
problems.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core updates from Greg KH:
"Here is the large set of driver core changes for 6.4-rc1.
Once again, a busy development cycle, with lots of changes happening
in the driver core in the quest to be able to move "struct bus" and
"struct class" into read-only memory, a task now complete with these
changes.
This will make the future rust interactions with the driver core more
"provably correct" as well as providing more obvious lifetime rules
for all busses and classes in the kernel.
The changes required for this did touch many individual classes and
busses as many callbacks were changed to take const * parameters
instead. All of these changes have been submitted to the various
subsystem maintainers, giving them plenty of time to review, and most
of them actually did so.
Other than those changes, included in here are a small set of other
things:
- kobject logging improvements
- cacheinfo improvements and updates
- obligatory fw_devlink updates and fixes
- documentation updates
- device property cleanups and const * changes
- firwmare loader dependency fixes.
All of these have been in linux-next for a while with no reported
problems"
* tag 'driver-core-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (120 commits)
device property: make device_property functions take const device *
driver core: update comments in device_rename()
driver core: Don't require dynamic_debug for initcall_debug probe timing
firmware_loader: rework crypto dependencies
firmware_loader: Strip off \n from customized path
zram: fix up permission for the hot_add sysfs file
cacheinfo: Add use_arch[|_cache]_info field/function
arch_topology: Remove early cacheinfo error message if -ENOENT
cacheinfo: Check cache properties are present in DT
cacheinfo: Check sib_leaf in cache_leaves_are_shared()
cacheinfo: Allow early level detection when DT/ACPI info is missing/broken
cacheinfo: Add arm64 early level initializer implementation
cacheinfo: Add arch specific early level initializer
tty: make tty_class a static const structure
driver core: class: remove struct class_interface * from callbacks
driver core: class: mark the struct class in struct class_interface constant
driver core: class: make class_register() take a const *
driver core: class: mark class_release() as taking a const *
driver core: remove incorrect comment for device_create*
MIPS: vpe-cmp: remove module owner pointer from struct class usage.
...
cpufreq_verify_current_freq checks() if the frequency returned by
the hardware has a slight delta with the valid frequency value
last set and returns "policy->cur" if the delta is within "1 MHz".
In the comparison, "policy->cur" is in "kHz" but it's compared
against HZ_PER_MHZ. So, the comparison range becomes "1 GHz".
Fix this by comparing against KHZ_PER_MHZ instead of HZ_PER_MHZ.
Fixes: f55ae08c89 ("cpufreq: Avoid unnecessary frequency updates due to mismatch")
Signed-off-by: Sanjay Chandrashekara <sanjayc@nvidia.com>
[ sumit gupta: Commit message update ]
Signed-off-by: Sumit Gupta <sumitg@nvidia.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Since the cpufreq core directly uses freq_table, for cpufreq drivers
that set their target_index() callback, make it mandatory for them to
set the same.
Since this is set per policy and normally from policy->init(), do this
from cpufreq_table_validate_and_sort() which gets called right after
->init().
Reported-by: Yajun Deng <yajun.deng@linux.dev>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
When echo an invalid val to scaling_min_freq:
> echo 123abc123 > scaling_min_freq
It looks weird to have a return val of 0:
> echo $?
> 0
Sane people won't echo strings like that into these interfaces but fuzz
tests may do. Also, maybe it's better to inform people if input is
invalid.
After this:
> echo 123abc123 > scaling_min_freq
> -bash: echo: write error: Invalid argument
Signed-off-by: qinyu <qinyu32@huawei.com>
Tested-by: zhangxiaofeng <zhangxiaofeng46@huawei.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Direct access to the struct bus_type dev_root pointer is going away soon
so replace that with a call to bus_get_dev_root() instead, which is what
it is there for.
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Cc: Len Brown <lenb@kernel.org>
Cc: linux-pm@vger.kernel.org
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lore.kernel.org/r/20230313182918.1312597-3-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Since commit ee6d3dd4ed ("driver core: make kobj_type constant.")
the driver core allows the usage of const struct kobj_type.
Take advantage of this to constify the structure definition to prevent
modification at runtime.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
All but a few drivers ignore the return value of
cpufreq_unregister_driver(). Those few that don't only call it after
cpufreq_register_driver() succeeded, in which case the call doesn't
fail.
Make the function return no value and add a WARN_ON for the case that
the function is called in an invalid situation (i.e. without a previous
successful call to cpufreq_register_driver()).
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Florian Fainelli <f.fainelli@gmail.com> # brcmstb-avs-cpufreq.c
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
In cpufreq_policy_alloc(), it will call uninitialed completion in
cpufreq_sysfs_release() when kobject_init_and_add() fails. And
that will cause a crash such as the following page fault in complete:
BUG: unable to handle page fault for address: fffffffffffffff8
[..]
RIP: 0010:complete+0x98/0x1f0
[..]
Call Trace:
kobject_put+0x1be/0x4c0
cpufreq_online.cold+0xee/0x1fd
cpufreq_add_dev+0x183/0x1e0
subsys_interface_register+0x3f5/0x4e0
cpufreq_register_driver+0x3b7/0x670
acpi_cpufreq_init+0x56c/0x1000 [acpi_cpufreq]
do_one_initcall+0x13d/0x780
do_init_module+0x1c3/0x630
load_module+0x6e67/0x73b0
__do_sys_finit_module+0x181/0x240
do_syscall_64+0x35/0x80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
Fixes: 4ebe36c94a ("cpufreq: Fix kobject memleak")
Signed-off-by: Yongqiang Liu <liuyongqiang13@huawei.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: 5.2+ <stable@vger.kernel.org> # 5.2+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
There is no need to check if the cpufreq driver implements callback
cpufreq_driver::target_index. The logic in the __resolve_freq uses
the frequency table available in the policy. It doesn't matter if the
driver provides 'target_index' or 'target' callback. It just has to
populate the 'policy->freq_table'.
Thus, check only frequency table during the frequency resolving call.
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Lukasz Luba <lukasz.luba@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
- Fix return error code in mtk_cpu_dvfs_info_init (Yang Yingliang).
- Minor cleanups and support for new boards for Qcom cpufreq drivers
(Bryan O'Donoghue, Konrad Dybcio, Pierre Gondois, and Yicong Yang).
- Fix sparse warnings for Tegra driver (Viresh Kumar).
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Merge tag 'cpufreq-arm-updates-5.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vireshk/pm
Pull cpufreq/ARM updates for 5.20-rc1 from Viresh Kumar:
"- Fix return error code in mtk_cpu_dvfs_info_init (Yang Yingliang).
- Minor cleanups and support for new boards for Qcom cpufreq drivers
(Bryan O'Donoghue, Konrad Dybcio, Pierre Gondois, and Yicong Yang).
- Fix sparse warnings for Tegra driver (Viresh Kumar)."
* tag 'cpufreq-arm-updates-5.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vireshk/pm:
cpufreq: tegra194: Staticize struct tegra_cpufreq_soc instances
dt-bindings: cpufreq: cpufreq-qcom-hw: Add SM6375 compatible
dt-bindings: opp: Add msm8939 to the compatible list
dt-bindings: opp: Add missing compat devices
dt-bindings: opp: opp-v2-kryo-cpu: Fix example binding checks
cpufreq: Change order of online() CB and policy->cpus modification
cpufreq: qcom-hw: Remove deprecated irq_set_affinity_hint() call
cpufreq: qcom-hw: Disable LMH irq when disabling policy
cpufreq: qcom-hw: Reset cancel_throttle when policy is re-enabled
cpufreq: qcom-cpufreq-hw: use HZ_PER_KHZ macro in units.h
cpufreq: mediatek: fix error return code in mtk_cpu_dvfs_info_init()
From a state where all policy->related_cpus are offline, putting one
of the policy's CPU back online re-activates the policy by:
1. Calling cpufreq_driver->online()
2. Setting the CPU in policy->cpus
qcom_cpufreq_hw_cpu_online() makes use of policy->cpus. Thus 1. and 2.
should be inverted to avoid having a policy->cpus empty. The
qcom-cpufreq-hw is the only driver affected by this.
Signed-off-by: Pierre Gondois <pierre.gondois@arm.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
With the new design in place, the show() and store() callbacks check if
the policy is active or not before proceeding any further to avoid
potential races. And in order to guarantee that cpufreq_policy_free()
must be called after clearing the policy->cpus mask, i.e. by marking the
policy inactive.
In order to avoid introducing a bug around this later, print a warning
message if we end up freeing an active policy.
Also update cpufreq_online() a bit to make sure we clear the cpus mask
for each error case before calling cpufreq_policy_free().
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This change was introduced long back by commit 4f750c9308 ("cpufreq:
Synchronize the cpufreq store_*() routines with CPU hotplug").
Since then, both cpufreq and hotplug core have been reworked and have
much better locking in place. The race mentioned in commit 4f750c9308
isn't possible anymore.
Drop the unnecessary locking.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Instead of specially adding a space for each CPU, except the first one,
lets add space for each of them and remove it at the end.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
cpufreq_offline() calls offline() and exit() under the policy rwsem
But they are called outside the rwsem in cpufreq_online().
Make cpufreq_online() call offline() and exit() as well as online() and
init() under the policy rwsem to achieve a clear lock relationship.
All of the init() and online() implementations in the tree only
initialize the policy object without attempting to acquire the policy
rwsem and they won't call cpufreq APIs attempting to acquire it.
Signed-off-by: Schspa Shi <schspa@gmail.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
[ rjw: Changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
If policy initialization fails after the sysfs files are created,
there is a possibility to end up running show()/store() callbacks
for half-initialized policies, which may have unpredictable
outcomes.
Abort show()/store() in such a case by making sure the policy is active.
Also dectivate the policy on such failures.
Signed-off-by: Schspa Shi <schspa@gmail.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
[ rjw: Subject and changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Currently, cpufreq_remove_dev() invokes the ->exit() driver callback
without holding the policy rwsem which is inconsistent with what
happens if ->exit() is invoked directly from cpufreq_offline().
It also manipulates the real_cpus mask and removes the CPU device
symlink without holding the policy rwsem, but cpufreq_offline() holds
the rwsem around the modifications thereof.
For consistency, modify cpufreq_remove_dev() to hold the policy rwsem
until the ->exit() callback has been called (or it has been determined
that it is not necessary to call it).
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Split the "core" part running under the policy rwsem out of
cpufreq_offline() to allow the locking in cpufreq_remove_dev() to be
rearranged more easily.
As a side-effect this eliminates the unlock label that's not needed
any more.
No expected functional impact.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Notice that cpufreq_offline() only needs to check policy_is_inactive()
once and rearrange the code in there to make that happen.
No expected functional impact.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
add_cpu_dev_symlink() is responsible for setting the CPUs in the
real_cpus mask, the reverse of which should be done from
remove_cpu_dev_symlink() to make it look clean and avoid any breakage
later on.
Move the call to clear the mask to remove_cpu_dev_symlink().
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This reverts commit f346e96267.
The commit tried to fix a possible real bug but it made it even worse.
The fix was simply buggy as now an error out to out_offline_policy or
out_exit_policy will try to release a semaphore which was never taken in
the first place. This works fine only if we failed late, i.e. via
out_destroy_policy.
Fixes: f346e96267 ("cpufreq: Fix possible race in cpufreq online error path")
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
For some platforms, the frequency returned by hardware may be slightly
different from what is provided in the frequency table. For example,
hardware may return 499 MHz instead of 500 MHz. In such cases it is
better to avoid getting into unnecessary frequency updates, as we may
end up switching policy->cur between the two and sending unnecessary
pre/post update notifications, etc.
This patch has chosen allows the hardware frequency and table frequency
to deviate by 1 MHz for now, we may want to increase it a bit later on
if someone still complains.
Reported-by: Rex-BC Chen <rex-bc.chen@mediatek.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Tested-by: Jia-wei Chang <jia-wei.chang@mediatek.com>
Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
When cpufreq online fails, the policy->cpus mask is not cleared and
policy->rwsem is released too early, so the driver can be invoked
via the cpuinfo_cur_freq sysfs attribute while its ->offline() or
->exit() callbacks are being run.
Take policy->clk as an example:
static int cpufreq_online(unsigned int cpu)
{
...
// policy->cpus != 0 at this time
down_write(&policy->rwsem);
ret = cpufreq_add_dev_interface(policy);
up_write(&policy->rwsem);
return 0;
out_destroy_policy:
for_each_cpu(j, policy->real_cpus)
remove_cpu_dev_symlink(policy, get_cpu_device(j));
up_write(&policy->rwsem);
...
out_exit_policy:
if (cpufreq_driver->exit)
cpufreq_driver->exit(policy);
clk_put(policy->clk);
// policy->clk is a wild pointer
...
^
|
Another process access
__cpufreq_get
cpufreq_verify_current_freq
cpufreq_generic_get
// acces wild pointer of policy->clk;
|
|
out_offline_policy: |
cpufreq_policy_free(policy); |
// deleted here, and will wait for no body reference
cpufreq_policy_put_kobj(policy);
}
Address this by modifying cpufreq_online() to release policy->rwsem
in the error path after the driver callbacks have run and to clear
policy->cpus before releasing the semaphore.
Fixes: 7106e02bae ("cpufreq: release policy->rwsem on error")
Signed-off-by: Schspa Shi <schspa@gmail.com>
[ rjw: Subject and changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This effectively revert '4bf8e582119e ("cpufreq: Remove ready()
callback")', in order to reintroduce the ready callback.
This is needed in order to be able to leave the thermal pressure
interrupts in the Qualcomm CPUfreq driver disabled during
initialization, so that it doesn't fire while related_cpus are still 0.
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
[ Viresh: Added the Chinese translation as well and updated commit msg ]
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
There are currently 2 ways to create a set of sysfs files for a
kobj_type, through the default_attrs field, and the default_groups
field. Move the cpufreq code to use default_groups field which has been
the preferred way since aa30f47cf6 ("kobject: Add support for default
attribute groups to kobj_type") so that we can soon get rid of the
obsolete default_attrs field.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The min and max frequency QoS requests in the cpufreq core are
initialized to whatever the current min and max frequency values are
at the init time, but if any of these values change later (for
example, cpuinfo.max_freq is updated by the driver), these initial
request values will be limiting the CPU frequency unnecessarily
unless they are changed by user space via sysfs.
To address this, initialize min_freq_req and max_freq_req to
FREQ_QOS_MIN_DEFAULT_VALUE and FREQ_QOS_MAX_DEFAULT_VALUE,
respectively, so they don't really limit anything until user
space updates them.
Reported-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Tested-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Make the comment in blocking_notifier_call_chain() easier to
understand.
Signed-off-by: Tang Yizhou <tangyizhou@huawei.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
When I hot added a CPU, I found 'cpufreq' directory was not created
below /sys/devices/system/cpu/cpuX/.
It is because get_cpu_device() failed in add_cpu_dev_symlink().
cpufreq_add_dev() is the .add_dev callback of a CPU subsys interface.
It will be called when the CPU device registered into the system.
The call chain is as follows:
register_cpu()
->device_register()
->device_add()
->bus_probe_device()
->cpufreq_add_dev()
But only after the CPU device has been registered, we can get the
CPU device by get_cpu_device(), otherwise it will return NULL.
Since we already have the CPU device in cpufreq_add_dev(), pass
it to add_cpu_dev_symlink().
I noticed that the 'kobj' of the CPU device has been added into
the system before cpufreq_add_dev().
Fixes: 2f0ba790df ("cpufreq: Fix creation of symbolic links to policy directories")
Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Let the governors schedutil, conservative and ondemand to work, if possible
on efficient frequencies only.
Signed-off-by: Vincent Donnefort <vincent.donnefort@arm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This newly introduced flag can be applied by a governor to a CPUFreq
relation, when looking for a frequency within the policy table. The
resolution would then only walk through efficient frequencies.
Even with the flag set, the policy max limit will still be honoured. If no
efficient frequencies can be found within the limits of the policy, an
inefficient one would be returned.
Signed-off-by: Vincent Donnefort <vincent.donnefort@arm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
When applying the policy min/max limits, the requested frequency is
simply clamped to not be out of range. It means, however, if one of the
boundaries isn't an available frequency, the frequency resolution can
return a value out of those limits, depending on the relation used.
e.g. freq{0,1,2} being available frequencies.
freq0 policy->min freq1 policy->max freq2
| | | | |
17kHz 18kHz 19kHz 20kHz 21kHz
__resolve_freq(21kHz, CPUFREQ_RELATION_L) -> 21kHz (out of bounds)
__resolve_freq(17kHz, CPUFREQ_RELATION_H) -> 17kHz (out of bounds)
If, during the policy init, we resolve the requested min/max to existing
frequencies, we ensure that any CPUFREQ_RELATION_* would resolve to a
frequency which is inside the policy min/max range.
Making the policy limits rigid helps to introduce the inefficient
frequencies support. Resolving an inefficient frequency to an efficient
one should not transgress policy->max (which can be set for thermal
reason) and having a value we can trust simplify this comparison.
Signed-off-by: Vincent Donnefort <vincent.donnefort@arm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This isn't used anymore, get rid of it.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Pull ARM cpufreq driver changes for v5.15 from Viresh Kumar:
"This contains:
- Update cpufreq-dt blocklist with more platforms (Bjorn Andersson).
- Allow freq changes from any CPU for qcom-hw driver (Taniya Das).
- Add DSVS interrupt's support for qcom-hw driver (Thara Gopinath).
- A new callback (->register_em()) to register EM at a more convenient
point of time."
* 'cpufreq/arm/linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/vireshk/pm:
cpufreq: qcom-hw: Set dvfs_possible_from_any_cpu cpufreq driver flag
cpufreq: blocklist more Qualcomm platforms in cpufreq-dt-platdev
cpufreq: qcom-cpufreq-hw: Add dcvs interrupt support
cpufreq: scmi: Use .register_em() to register with energy model
cpufreq: vexpress: Use .register_em() to register with energy model
cpufreq: scpi: Use .register_em() to register with energy model
cpufreq: qcom-cpufreq-hw: Use .register_em() to register with energy model
cpufreq: omap: Use .register_em() to register with energy model
cpufreq: mediatek: Use .register_em() to register with energy model
cpufreq: imx6q: Use .register_em() to register with energy model
cpufreq: dt: Use .register_em() to register with energy model
cpufreq: Add callback to register with energy model
cpufreq: vexpress: Set CPUFREQ_IS_COOLING_DEV flag
Many cpufreq drivers register with the energy model for each policy and
do exactly the same thing. Follow the footsteps of thermal-cooling, to
get it done from the cpufreq core itself.
Provide a new callback, which will be called, if present, by the cpufreq
core at the right moment (more on that in the code's comment). Also
provide a generic implementation that uses dev_pm_opp_of_register_em().
This also allows us to register with the EM at a later point of time,
compared to ->init(), from where the EM core can access cpufreq policy
directly using cpufreq_cpu_get() type of helpers and perform other work,
like marking few frequencies inefficient, this will be done separately.
Reviewed-by: Quentin Perret <qperret@google.com>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
The functions get_online_cpus() and put_online_cpus() have been
deprecated during the CPU hotplug rework. They map directly to
cpus_read_lock() and cpus_read_unlock().
Replace deprecated CPU-hotplug functions with the official version.
The behavior remains unchanged.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Commit e3c0623608 ("cpufreq: add cpufreq_driver_resolve_freq()")
introduced this callback, back in 2016, for drivers that provide the
->target() callback.
The kernel hasn't seen a single user of it in the past 5 years and
it is not likely to be used any time soon.
Remove it for now.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
[ rjw: Changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
__cpufreq_driver_target() open codes cpufreq_driver_resolve_freq(), lets
make the former reuse the later.
Separate out __resolve_freq() to accept relation as well as an argument
and use it at both the locations.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Now that all users of ->stop_cpu() have been migrated to using other
callbacks, drop it from the core.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
[ rjw: Minor edits in the subject and changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
In the CPU removal path the ->offline() callback provided by the
driver is always invoked before ->exit(), but in the cpufreq_online()
error path it is not, so ->exit() is expected to somehow know the
context in which it has been called and act accordingly.
That is less than straightforward, so make cpufreq_online() invoke
the driver's ->offline() callback, if present, on errors before
->exit() too.
This only potentially affects intel_pstate.
Fixes: 91a12e91dc ("cpufreq: Allow light-weight tear down and bring up of CPUs")
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Macro 'for_each_policy' has become unused since commit
f963735a3c ("cpufreq: Create for_each_{in}active_policy()"), so
remove it.
Signed-off-by: Shaokun Zhang <zhangshaokun@hisilicon.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Change 'Terget' to 'Target'.
Should be Target.
Signed-off-by: Yue Hu <huyue2@yulong.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
[ rjw: Subject edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
During cpufreq driver's registration, if the ->init() callback for all
the CPUs fail then there is not much point in keeping the driver around
as it will only account for more of unnecessary noise, for example
cpufreq core will try to suspend/resume the driver which never got
registered properly.
The removal of such a driver is avoided if the driver carries the
CPUFREQ_STICKY flag. This was added way back [1] in 2004 and perhaps no
one should ever need it now. A lot of drivers do set this flag, probably
because they just copied it from other drivers.
This was added earlier for some platforms [2] because their cpufreq
drivers were getting registered before the CPUs were registered with
subsys framework. And hence they used to fail.
The same isn't true anymore though. The current code flow in the kernel
is:
start_kernel()
-> kernel_init()
-> kernel_init_freeable()
-> do_basic_setup()
-> driver_init()
-> cpu_dev_init()
-> subsys_system_register() //For CPUs
-> do_initcalls()
-> cpufreq_register_driver()
Clearly, the CPUs will always get registered with subsys framework
before any cpufreq driver can get probed. Remove the flag and update the
relevant drivers.
Link: https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git/commit/include/linux/cpufreq.h?id=7cc9f0d9a1ab04cedc60d64fd8dcf7df224a3b4d # [1]
Link: https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git/commit/arch/arm/mach-sa1100/cpu-sa1100.c?id=f59d3bbe35f6268d729f51be82af8325d62f20f5 # [2]
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Viresh Kumar