commit 2a6c727387 ("cpufreq: Initialize cpufreq-based
frequency-invariance later") postponed the frequency invariance
initialization to avoid disabling it in the error case.
This isn't locking safe, instead move the initialization up before
the subsys interface is registered (which will rebuild the
sched_domains) and add the corresponding disable on the error path.
Observed lockdep without this patch:
[ 0.989686] ======================================================
[ 0.989688] WARNING: possible circular locking dependency detected
[ 0.989690] 6.17.0-rc4-cix-build+ #31 Tainted: G S
[ 0.989691] ------------------------------------------------------
[ 0.989692] swapper/0/1 is trying to acquire lock:
[ 0.989693] ffff800082ada7f8 (sched_energy_mutex){+.+.}-{4:4}, at: rebuild_sched_domains_energy+0x30/0x58
[ 0.989705]
but task is already holding lock:
[ 0.989706] ffff000088c89bc8 (&policy->rwsem){+.+.}-{4:4}, at: cpufreq_online+0x7f8/0xbe0
[ 0.989713]
which lock already depends on the new lock.
Fixes: 2a6c727387 ("cpufreq: Initialize cpufreq-based frequency-invariance later")
Signed-off-by: Christian Loehle <christian.loehle@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Currently, cpufreq allows drivers to implement both ->target() and
->target_index() callbacks, but that can lead to ambiguous or incorrect
behavior.
For this reason, prevent cpufreq drivers implementing both ->target()
and ->target_index() at the same time from registering.
This check can help to catch driver implementation mistakes early and
improve overall robustness, without affecting existing valid drivers.
Signed-off-by: Zihuan Zhang <zhangzihuan@kylinos.cn>
Link: https://patch.msgid.link/20250908085738.31602-1-zhangzihuan@kylinos.cn
[ rjw: Subject adjustment and changelog rewrite ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Follow cleanup.h recommendations and always define and assign variables
in one statement when __free() is used.
No intentional functional impact.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Link: https://patch.msgid.link/4691667.LvFx2qVVIh@rafael.j.wysocki
Change the 'ret' variable in store_scaling_setspeed() from unsigned int to
int, as it needs to store either negative error codes or zero returned
by kstrtouint().
No effect on runtime.
Signed-off-by: Qianfeng Rong <rongqianfeng@vivo.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Link: https://patch.msgid.link/20250902114545.651661-2-rongqianfeng@vivo.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Since commit e0b3165ba5 ("cpufreq: add 'freq_table' in struct
cpufreq_policy"), freq_table has been stored in struct cpufreq_policy
instead of being maintained separately.
However, several helpers in freq_table.c still take both policy and
freq_table as parameters, even though policy->freq_table can always be
used. This leads to redundant function arguments and increases the
chance of inconsistencies.
This patch removes the unnecessary freq_table argument from these
functions and updates their callers to only pass policy. This makes
the code simpler, more consistent, and avoids duplication.
Signed-off-by: Zihuan Zhang <zhangzihuan@kylinos.cn>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Link: https://patch.msgid.link/20250902073323.48330-1-zhangzihuan@kylinos.cn
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
cpufreq drivers are supposed to use either ->setpolicy() or
->target()/->target_index().
Simplify the existing check by collapsing it into a single boolean
expression:
(!!driver->setpolicy == (driver->target_index || driver->target))
This is a readability/maintainability cleanup and keeps the semantics
unchanged.
No functional change intended.
Signed-off-by: Zihuan Zhang <zhangzihuan@kylinos.cn>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Link: https://patch.msgid.link/20250822070424.166795-3-zhangzihuan@kylinos.cn
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Most kernel code using strncasecmp()/strncmp() passes strlen("xxx")
as the length argument. cpufreq_parse_policy() previously used
CPUFREQ_NAME_LEN (16), which is longer than the actual strings
("performance" is 11 chars, "powersave" is 9 chars).
This patch switches to strlen() for the comparison, making the
matching slightly more permissive (e.g., "powersavexxx" will now
also match "powersave"). While this is unlikely to cause functional
issues, it aligns cpufreq with common kernel style and makes the
behavior more intuitive.
Signed-off-by: Zihuan Zhang <zhangzihuan@kylinos.cn>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Link: https://patch.msgid.link/20250822070424.166795-2-zhangzihuan@kylinos.cn
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
When a cpufreq driver registers the first policy, it may attempt to
initialize the policy governor from `last_governor`. However, this is
meaningless for the first policy instance, because `last_governor` is
only updated when policies are removed (e.g. during CPU offline).
The `last_governor` mechanism is intended to restore the previously
used governor across CPU hotplug events. For the very first policy,
there is no "previous governor" to restore, so calling
get_governor(last_governor) is unnecessary and potentially confusing.
Skip looking up `last_governor` when registering the first policy.
Instead, it directly uses the default governor after all governors
have been registered and are available.
This avoids meaningless lookups, reduces unnecessary module reference
handling, and simplifies the initial policy path.
Signed-off-by: Zihuan Zhang <zhangzihuan@kylinos.cn>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Lifeng Zheng <zhenglifeng1@huawei.com>
Link: https://patch.msgid.link/20250725041450.68754-1-zhangzihuan@kylinos.cn
[ rjw: Subject and changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
- tegra124: Allow building as a module (Aaron Kling).
- Minor cleanups for Rust cpufreq and cpumask APIs and fix MAINTAINERS
entry for cpu.rs (Abhinav Ananthu, Ritvik Gupta, and Lukas Bulwahn).
- Minor cleanups for miscellaneous cpufreq drivers (Arnd Bergmann, Dan
Carpenter, Krzysztof Kozlowski, Sven Peter, and Svyatoslav Ryhel).
-----BEGIN PGP SIGNATURE-----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=jj94
-----END PGP SIGNATURE-----
Merge tag 'cpufreq-arm-updates-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/vireshk/pm
Merge CPUFreq updates for 6.17 from Viresh Kumar:
"- tegra124: Allow building as a module (Aaron Kling).
- Minor cleanups for Rust cpufreq and cpumask APIs and fix MAINTAINERS
entry for cpu.rs (Abhinav Ananthu, Ritvik Gupta, and Lukas Bulwahn).
- Minor cleanups for miscellaneous cpufreq drivers (Arnd Bergmann, Dan
Carpenter, Krzysztof Kozlowski, Sven Peter, and Svyatoslav Ryhel)."
* tag 'cpufreq-arm-updates-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/vireshk/pm:
drivers: cpufreq: add Tegra114 support
rust: cpumask: Replace `MaybeUninit` and `mem::zeroed` with `Opaque` APIs
cpufreq: tegra124: Allow building as a module
cpufreq: dt: Add register helper
cpufreq: Export disable_cpufreq()
cpufreq: armada-8k: Fix off by one in armada_8k_cpufreq_free_table()
cpufreq: armada-8k: make both cpu masks static
rust: cpufreq: use c_ types from kernel prelude
rust: cpufreq: Ensure C ABI compatibility in all unsafe
cpufreq: brcmstb-avs: Fully open-code compatible for grepping
cpufreq: apple: drop default ARCH_APPLE in Kconfig
MAINTAINERS: adjust file entry in CPU HOTPLUG
Detect the result of starting old governor in cpufreq_set_policy(). If it
fails, exit the governor and clear policy->governor.
Signed-off-by: Lifeng Zheng <zhenglifeng1@huawei.com>
Link: https://patch.msgid.link/20250709104145.2348017-5-zhenglifeng1@huawei.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Move the check of cpufreq_driver->get into cpufreq_verify_current_freq() in
case of calling it without check.
Signed-off-by: Lifeng Zheng <zhenglifeng1@huawei.com>
Link: https://patch.msgid.link/20250709104145.2348017-4-zhenglifeng1@huawei.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
In cpufreq_policy_put_kobj(), policy->rwsem is used. But in
cpufreq_policy_alloc(), if freq_qos_add_notifier() returns an error, error
path via err_kobj_remove or err_min_qos_notifier will be reached and
cpufreq_policy_put_kobj() will be called before policy->rwsem is
initialized. Thus, the calling of init_rwsem() should be moved to where
before these two error paths can be reached.
Fixes: 67d874c3b2 ("cpufreq: Register notifiers with the PM QoS framework")
Signed-off-by: Lifeng Zheng <zhenglifeng1@huawei.com>
Link: https://patch.msgid.link/20250709104145.2348017-3-zhenglifeng1@huawei.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The cpufreq-based invariance is enabled in cpufreq_register_driver(),
but never disabled after registration fails. Move the invariance
initialization to where all other initializations have been successfully
done to solve this problem.
Fixes: 874f635310 ("cpufreq: report whether cpufreq supports Frequency Invariance (FI)")
Signed-off-by: Lifeng Zheng <zhenglifeng1@huawei.com>
Link: https://patch.msgid.link/20250709104145.2348017-2-zhenglifeng1@huawei.com
[ rjw: New subject ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The has_target() checks in __cpufreq_offline() are duplicate.
Remove one of them and put the operations of exiting governor together
with storing last governor's name.
Signed-off-by: Lifeng Zheng <zhenglifeng1@huawei.com>
Link: https://patch.msgid.link/20250623133402.3120230-5-zhenglifeng1@huawei.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
After commit c034b02e21 ("cpufreq: expose scaling_cur_freq sysfs file
for set_policy() drivers"), the file scaling_cur_freq is exposed to all
drivers.
No need to create this file separately. It's better to be contained in
cpufreq_attrs.
Signed-off-by: Lifeng Zheng <zhenglifeng1@huawei.com>
Link: https://patch.msgid.link/20250623133402.3120230-4-zhenglifeng1@huawei.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This is used by the tegra124-cpufreq driver.
Signed-off-by: Aaron Kling <webgeek1234@gmail.com>
Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
In store_scaling_setspeed(), sscanf is still used to read to sysfs.
Newer kstrtox provide more features including overflow protection,
better errorhandling and allows for other systems of numeration. It
is therefore better to update sscanf() to kstrtouint().
Signed-off-by: Bowen Yu <yubowen8@huawei.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Link: https://patch.msgid.link/20250519070938.931396-1-yubowen8@huawei.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Setting the length of str_governor with a magic number could cause
overflow when max length increases, it is better to use the defined
macro in this case.
Signed-off-by: Bowen Yu <yubowen8@huawei.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Link: https://patch.msgid.link/20250519070908.930879-1-yubowen8@huawei.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Lockdep reports a possible circular locking dependency [1] when
cpu_hotplug_lock is acquired inside store_local_boost(), after
policy->rwsem has already been taken by store().
However, the boost update is strictly per-policy and does not
access shared state or iterate over all policies.
Since policy->rwsem is already held, this is enough to serialize
against concurrent topology changes for the current policy.
Remove the cpus_read_lock() to resolve the lockdep warning and
avoid unnecessary locking.
[1]
======================================================
WARNING: possible circular locking dependency detected
6.15.0-rc6-debug-gb01fc4eca73c #1 Not tainted
------------------------------------------------------
power-profiles-/588 is trying to acquire lock:
ffffffffb3a7d910 (cpu_hotplug_lock){++++}-{0:0}, at: store_local_boost+0x56/0xd0
but task is already holding lock:
ffff8b6e5a12c380 (&policy->rwsem){++++}-{4:4}, at: store+0x37/0x90
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #2 (&policy->rwsem){++++}-{4:4}:
down_write+0x29/0xb0
cpufreq_online+0x7e8/0xa40
cpufreq_add_dev+0x82/0xa0
subsys_interface_register+0x148/0x160
cpufreq_register_driver+0x15d/0x260
amd_pstate_register_driver+0x36/0x90
amd_pstate_init+0x1e7/0x270
do_one_initcall+0x68/0x2b0
kernel_init_freeable+0x231/0x270
kernel_init+0x15/0x130
ret_from_fork+0x2c/0x50
ret_from_fork_asm+0x11/0x20
-> #1 (subsys mutex#3){+.+.}-{4:4}:
__mutex_lock+0xc2/0x930
subsys_interface_register+0x7f/0x160
cpufreq_register_driver+0x15d/0x260
amd_pstate_register_driver+0x36/0x90
amd_pstate_init+0x1e7/0x270
do_one_initcall+0x68/0x2b0
kernel_init_freeable+0x231/0x270
kernel_init+0x15/0x130
ret_from_fork+0x2c/0x50
ret_from_fork_asm+0x11/0x20
-> #0 (cpu_hotplug_lock){++++}-{0:0}:
__lock_acquire+0x10ed/0x1850
lock_acquire.part.0+0x69/0x1b0
cpus_read_lock+0x2a/0xc0
store_local_boost+0x56/0xd0
store+0x50/0x90
kernfs_fop_write_iter+0x132/0x200
vfs_write+0x2b3/0x590
ksys_write+0x74/0xf0
do_syscall_64+0xbb/0x1d0
entry_SYSCALL_64_after_hwframe+0x56/0x5e
Signed-off-by: Seyediman Seyedarab <ImanDevel@gmail.com>
Link: https://patch.msgid.link/20250513015726.1497-1-ImanDevel@gmail.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Policy locking was added to cpufreq_policy_is_good_for_eas() by commit
4854649b1f ("cpufreq/sched: Move cpufreq-specific EAS checks to
cpufreq") to address a theoretical race condition, but it turned out to
introduce a circular locking dependency between the policy rwsem and
sched_domains_mutex via cpuset_mutex. This leads to a board lockup on
OdroidN2 that is based on the ARM64 Amlogic Meson SoC.
Drop the policy locking from cpufreq_policy_is_good_for_eas() to address
this issue.
Fixes: 4854649b1f ("cpufreq/sched: Move cpufreq-specific EAS checks to cpufreq")
Closes: https://lore.kernel.org/linux-pm/1bf3df62-0641-459f-99fc-fd511e564b84@samsung.com/
Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://patch.msgid.link/2806514.mvXUDI8C0e@rjwysocki.net
Doing cpufreq-specific EAS checks that require accessing policy
internals directly from sched_is_eas_possible() is a bit unfortunate,
so introduce cpufreq_ready_for_eas() in cpufreq, move those checks
into that new function and make sched_is_eas_possible() call it.
While at it, address a possible race between the EAS governor check
and governor change by doing the former under the policy rwsem.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Christian Loehle <christian.loehle@arm.com>
Tested-by: Christian Loehle <christian.loehle@arm.com>
Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Link: https://patch.msgid.link/2317800.iZASKD2KPV@rjwysocki.net
Commit 7491cdf46b ("cpufreq: Avoid using inconsistent policy->min and
policy->max") overlooked the fact that policy->min and policy->max were
accessed directly in cpufreq_frequency_table_target() and in the
functions called by it. Consequently, the changes made by that commit
led to problems with setting policy limits.
Address this by passing the target frequency limits to __resolve_freq()
and cpufreq_frequency_table_target() and propagating them to the
functions called by the latter.
Fixes: 7491cdf46b ("cpufreq: Avoid using inconsistent policy->min and policy->max")
Cc: 5.16+ <stable@vger.kernel.org> # 5.16+
Closes: https://lore.kernel.org/linux-pm/aAplED3IA_J0eZN0@linaro.org/
Reported-by: Stephan Gerhold <stephan.gerhold@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Stephan Gerhold <stephan.gerhold@linaro.org>
Reviewed-by: Lifeng Zheng <zhenglifeng1@huawei.com>
Link: https://patch.msgid.link/5896780.DvuYhMxLoT@rjwysocki.net
If the global boost flag is enabled and policy boost flag is disabled, a
call to `cpufreq_boost_trigger_state(true)` must enable the policy's
boost state.
The current code misses that because of an optimization. Fix it.
Suggested-by: Lifeng Zheng <zhenglifeng1@huawei.com>
Reviewed-by: Lifeng Zheng <zhenglifeng1@huawei.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Link: https://patch.msgid.link/852ff11c589e6300730d207baac195b2d9d8b95f.1745511526.git.viresh.kumar@linaro.org
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
If the global boost flag was enabled and policy boost flag was disabled
before a suspend resume cycle, cpufreq_online() will enable the policy
boost flag on resume.
While it is important for the policy boost flag to mirror the global
boost flag when a policy is first created, it should be avoided when the
policy is reinitialized (for example after a suspend resume cycle).
Though, if the global boost flag is disabled at this point of time, we
want to make sure policy boost flag is disabled too.
Reviewed-by: Lifeng Zheng <zhenglifeng1@huawei.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Link: https://patch.msgid.link/de5c72a0af101049204305c73cd30eb3a3e7b4a0.1745511526.git.viresh.kumar@linaro.org
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Since cpufreq_driver_resolve_freq() can run in parallel with
cpufreq_set_policy() and there is no synchronization between them,
the former may access policy->min and policy->max while the latter
is updating them and it may see intermediate values of them due
to the way the update is carried out. Also the compiler is free
to apply any optimizations it wants both to the stores in
cpufreq_set_policy() and to the loads in cpufreq_driver_resolve_freq()
which may result in additional inconsistencies.
To address this, use WRITE_ONCE() when updating policy->min and
policy->max in cpufreq_set_policy() and use READ_ONCE() for reading
them in cpufreq_driver_resolve_freq(). Moreover, rearrange the update
in cpufreq_set_policy() to avoid storing intermediate values in
policy->min and policy->max with the help of the observation that
their new values are expected to be properly ordered upfront.
Also modify cpufreq_driver_resolve_freq() to take the possible reverse
ordering of policy->min and policy->max, which may happen depending on
the ordering of operations when this function and cpufreq_set_policy()
run concurrently, into account by always honoring the max when it
turns out to be less than the min (in case it comes from thermal
throttling or similar).
Fixes: 1517176906 ("cpufreq: Make policy min/max hard requirements")
Cc: 5.16+ <stable@vger.kernel.org> # 5.16+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Christian Loehle <christian.loehle@arm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Link: https://patch.msgid.link/5907080.DvuYhMxLoT@rjwysocki.net
A recent change has introduced a bug into cpufreq_get_policy(), but this
function is not used, so it's better to drop it altogether.
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
Link: https://patch.msgid.link/2802770.mvXUDI8C0e@rjwysocki.net
Since cpufreq_update_limits() obtains a cpufreq policy pointer for the
given CPU and reference counts the corresponding policy object, it may
as well pass the policy pointer to the cpufreq driver's ->update_limits()
callback which allows that callback to avoid invoking cpufreq_cpu_get()
for the same CPU.
Accordingly, redefine ->update_limits() to take a policy pointer instead
of a CPU number and update both drivers implementing it, intel_pstate
and amd-pstate, as needed.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
Tested-by: Sudeep Holla <sudeep.holla@arm.com>
Link: https://patch.msgid.link/8560367.NyiUUSuA9g@rjwysocki.net
Since cpufreq_update_limits() obtains a cpufreq policy pointer for the
given CPU and reference counts the object pointed to by it, calling
cpufreq_update_policy() from cpufreq_update_limits() is somewhat
wasteful because that function calls cpufreq_cpu_get() on the same
CPU again.
To avoid that unnecessary overhead, move the part of the code running
under the policy rwsem from cpufreq_update_policy() to a new function
called cpufreq_policy_refresh() and invoke that new function from
both cpufreq_update_policy() and cpufreq_update_limits().
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
Tested-by: Sudeep Holla <sudeep.holla@arm.com>
Link: https://patch.msgid.link/6047110.MhkbZ0Pkbq@rjwysocki.net
Use __free() for policy reference counting cleanup where applicable in
the cpufreq core.
No intentional functional impact.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
Tested-by: Sudeep Holla <sudeep.holla@arm.com>
Link: https://patch.msgid.link/9437968.CDJkKcVGEf@rjwysocki.net
Since cpufreq_cpu_acquire() and cpufreq_cpu_release() have no more
users in the tree, remove them.
No intentional functional impact.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
Tested-by: Sudeep Holla <sudeep.holla@arm.com>
Link: https://patch.msgid.link/3880470.kQq0lBPeGt@rjwysocki.net
Instead of using cpufreq_cpu_acquire() and cpufreq_cpu_release() in
cpufreq_update_policy(), which is the last user of these functions,
make it use __free() for policy reference counting cleanup and the
"write" locking guard for policy locking.
No intentional functional impact.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
Tested-by: Sudeep Holla <sudeep.holla@arm.com>
Link: https://patch.msgid.link/22654186.EfDdHjke4D@rjwysocki.net
Introduce "read" and "write" locking guards for cpufreq policies and use
them where applicable in the cpufreq core.
No intentional functional impact.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
Tested-by: Sudeep Holla <sudeep.holla@arm.com>
Link: https://patch.msgid.link/8518682.T7Z3S40VBb@rjwysocki.net
In preparation for the introduction of cpufreq policy locking guards,
move the part of cpufreq_online() that is carried out under the policy
rwsem into a separate function called cpufreq_policy_online().
No intentional functional impact.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
Tested-by: Sudeep Holla <sudeep.holla@arm.com>
Link: https://patch.msgid.link/3354747.aeNJFYEL58@rjwysocki.net
Notice that the policy->cpu update in cpufreq_policy_alloc() can be
moved to cpufreq_online() and then it can be carried out under the
policy rwsem, along with the clearing of policy->governor (unnecessary
in the "new policy" code branch, but also not harmful). If this is
done, the bottom parts of the "if (policy)" branches become identical
and they can be collapsed and moved below the conditional.
Modify the code accordingly which makes it somewhat easier to follow.
No intentional functional impact.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
Tested-by: Sudeep Holla <sudeep.holla@arm.com>
Link: https://patch.msgid.link/13741234.uLZWGnKmhe@rjwysocki.net
Since acpi_processor_notify() can be called before registering a cpufreq
driver or even in cases when a cpufreq driver is not registered at all,
cpufreq_update_limits() needs to check if a cpufreq driver is present
and prevent it from being unregistered.
For this purpose, make it call cpufreq_cpu_get() to obtain a cpufreq
policy pointer for the given CPU and reference count the corresponding
policy object, if present.
Fixes: 5a25e3f7cc ("cpufreq: intel_pstate: Driver-specific handling of _PPC updates")
Closes: https://lore.kernel.org/linux-acpi/Z-ShAR59cTow0KcR@mail-itl
Reported-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Link: https://patch.msgid.link/1928789.tdWV9SEqCh@rjwysocki.net
- Manage sysfs attributes and boost frequencies efficiently from
cpufreq core to reduce boilerplate code in drivers (Viresh Kumar).
- Minor cleanups to cpufreq drivers (Aaron Kling, Benjamin Schneider,
Dhananjay Ugwekar, Imran Shaik, zuoqian).
- Migrate some cpufreq drivers to using for_each_present_cpu() (Jacky
Bai).
- cpufreq-qcom-hw DT binding fixes (Krzysztof Kozlowski).
- Use str_enable_disable() helper in cpufreq_online() (Lifeng Zheng).
- Optimize the amd-pstate driver to avoid cases where call paths end
up calling the same writes multiple times and needlessly caching
variables through code reorganization, locking overhaul and tracing
adjustments (Mario Limonciello, Dhananjay Ugwekar).
- Make it possible to avoid enabling capacity-aware scheduling (CAS) in
the intel_pstate driver and relocate a check for out-of-band (OOB)
platform handling in it to make it detect OOB before checking HWP
availability (Rafael Wysocki).
- Fix dbs_update() to avoid inadvertent conversions of negative integer
values to unsigned int which causes CPU frequency selection to be
inaccurate in some cases when the "conservative" cpufreq governor is
in use (Jie Zhan).
- Update the handling of the most recent idle intervals in the menu
cpuidle governor to prevent useful information from being discarded
by it in some cases and improve the prediction accuracy (Rafael
Wysocki).
- Make it possible to tell the intel_idle driver to ignore its built-in
table of idle states for the given processor, clean up the handling
of auto-demotion disabling on Baytrail and Cherrytrail chips in it,
and update its MAINTAINERS entry (David Arcari, Artem Bityutskiy,
Rafael Wysocki).
- Make some cpuidle drivers use for_each_present_cpu() instead of
for_each_possible_cpu() during initialization to avoid issues
occurring when nosmp or maxcpus=0 are used (Jacky Bai).
- Clean up the Energy Model handling code somewhat (Rafael Wysocki).
- Use kfree_rcu() to simplify the handling of runtime Energy Model
updates (Li RongQing).
- Add an entry for the Energy Model framework to MAINTAINERS as
properly maintained (Lukasz Luba).
- Address RCU-related sparse warnings in the Energy Model code (Rafael
Wysocki).
- Remove ENERGY_MODEL dependency on SMP and allow it to be selected
when DEVFREQ is set without CPUFREQ so it can be used on a wider
range of systems (Jeson Gao).
- Unify error handling during runtime suspend and runtime resume in the
core to help drivers to implement more consistent runtime PM error
handling (Rafael Wysocki).
- Drop a redundant check from pm_runtime_force_resume() and rearrange
documentation related to __pm_runtime_disable() (Rafael Wysocki).
- Rework the handling of the "smart suspend" driver flag in the PM core
to avoid issues hat may occur when drivers using it depend on some
other drivers and clean up the related PM core code (Rafael Wysocki,
Colin Ian King).
- Fix the handling of devices with the power.direct_complete flag set
if device_suspend() returns an error for at least one device to avoid
situations in which some of them may not be resumed (Rafael Wysocki).
- Use mutex_trylock() in hibernate_compressor_param_set() to avoid a
possible deadlock that may occur if the "compressor" hibernation
module parameter is accessed during the registration of a new
ieee80211 device (Lizhi Xu).
- Suppress sleeping parent warning in device_pm_add() in the case when
new children are added under a device with the power.direct_complete
set after it has been processed by device_resume() (Xu Yang).
- Remove needless return in three void functions related to system
wakeup (Zijun Hu).
- Replace deprecated kmap_atomic() with kmap_local_page() in the
hibernation core code (David Reaver).
- Remove unused helper functions related to system sleep (David Alan
Gilbert).
- Clean up s2idle_enter() so it does not lock and unlock CPU offline
in vain and update comments in it (Ulf Hansson).
- Clean up broken white space in dpm_wait_for_children() (Geert
Uytterhoeven).
- Update the cpupower utility to fix lib version-ing in it and memory
leaks in error legs, remove hard-coded values, and implement CPU
physical core querying (Thomas Renninger, John B. Wyatt IV, Shuah
Khan, Yiwei Lin, Zhongqiu Han).
-----BEGIN PGP SIGNATURE-----
iQFGBAABCAAwFiEEcM8Aw/RY0dgsiRUR7l+9nS/U47UFAmfhhTYSHHJqd0Byand5
c29ja2kubmV0AAoJEO5fvZ0v1OO16/gIAKuRiG1fFgUcUSXC1iFu42vrB/1i4wpA
02GICACqM3K6/5jd3ct/WOU28GUgDs+xcmqH7CnMaM6y9nXEWjWarmSfFekAO+0q
TPtQ7xTy0hBCB3he1P2uLKBJBin4Wn47U9/rvs4J7mQd5zDxTINKIiVoHg2lEE+s
HAeSoNRb2sp5IZDm9+/LfhHNYRP1mJ97cbZlymqctGB3xgDL7qMLid/1+gFPHAQS
4/LXj3IgyU8DpA/j5nhtpaAqjN5g2QxIUfQgADRIcESK99Y/7aAMs1/G0WhJKaay
9yx+4/xmkGvVCZQx1DphksFLISEzltY0SFWLsoppPzBTGVEW2GQQsNI=
=LqVy
-----END PGP SIGNATURE-----
Merge tag 'pm-6.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull power management updates from Rafael Wysocki:
"These are dominated by cpufreq updates which in turn are dominated by
updates related to boost support in the core and drivers and
amd-pstate driver optimizations.
Apart from the above, there are some cpuidle updates including a
rework of the most recent idle intervals handling in the venerable
menu governor that leads to significant improvements in some
performance benchmarks, as the governor is now more likely to predict
a shorter idle duration in some cases, and there are updates of the
core device power management code, mostly related to system suspend
and resume, that should help to avoid potential issues arising when
the drivers of devices depending on one another want to use different
optimizations.
There is also a usual collection of assorted fixes and cleanups,
including removal of some unused code.
Specifics:
- Manage sysfs attributes and boost frequencies efficiently from
cpufreq core to reduce boilerplate code in drivers (Viresh Kumar)
- Minor cleanups to cpufreq drivers (Aaron Kling, Benjamin Schneider,
Dhananjay Ugwekar, Imran Shaik, zuoqian)
- Migrate some cpufreq drivers to using for_each_present_cpu() (Jacky
Bai)
- cpufreq-qcom-hw DT binding fixes (Krzysztof Kozlowski)
- Use str_enable_disable() helper in cpufreq_online() (Lifeng Zheng)
- Optimize the amd-pstate driver to avoid cases where call paths end
up calling the same writes multiple times and needlessly caching
variables through code reorganization, locking overhaul and tracing
adjustments (Mario Limonciello, Dhananjay Ugwekar)
- Make it possible to avoid enabling capacity-aware scheduling (CAS)
in the intel_pstate driver and relocate a check for out-of-band
(OOB) platform handling in it to make it detect OOB before checking
HWP availability (Rafael Wysocki)
- Fix dbs_update() to avoid inadvertent conversions of negative
integer values to unsigned int which causes CPU frequency selection
to be inaccurate in some cases when the "conservative" cpufreq
governor is in use (Jie Zhan)
- Update the handling of the most recent idle intervals in the menu
cpuidle governor to prevent useful information from being discarded
by it in some cases and improve the prediction accuracy (Rafael
Wysocki)
- Make it possible to tell the intel_idle driver to ignore its
built-in table of idle states for the given processor, clean up the
handling of auto-demotion disabling on Baytrail and Cherrytrail
chips in it, and update its MAINTAINERS entry (David Arcari, Artem
Bityutskiy, Rafael Wysocki)
- Make some cpuidle drivers use for_each_present_cpu() instead of
for_each_possible_cpu() during initialization to avoid issues
occurring when nosmp or maxcpus=0 are used (Jacky Bai)
- Clean up the Energy Model handling code somewhat (Rafael Wysocki)
- Use kfree_rcu() to simplify the handling of runtime Energy Model
updates (Li RongQing)
- Add an entry for the Energy Model framework to MAINTAINERS as
properly maintained (Lukasz Luba)
- Address RCU-related sparse warnings in the Energy Model code
(Rafael Wysocki)
- Remove ENERGY_MODEL dependency on SMP and allow it to be selected
when DEVFREQ is set without CPUFREQ so it can be used on a wider
range of systems (Jeson Gao)
- Unify error handling during runtime suspend and runtime resume in
the core to help drivers to implement more consistent runtime PM
error handling (Rafael Wysocki)
- Drop a redundant check from pm_runtime_force_resume() and rearrange
documentation related to __pm_runtime_disable() (Rafael Wysocki)
- Rework the handling of the "smart suspend" driver flag in the PM
core to avoid issues hat may occur when drivers using it depend on
some other drivers and clean up the related PM core code (Rafael
Wysocki, Colin Ian King)
- Fix the handling of devices with the power.direct_complete flag set
if device_suspend() returns an error for at least one device to
avoid situations in which some of them may not be resumed (Rafael
Wysocki)
- Use mutex_trylock() in hibernate_compressor_param_set() to avoid a
possible deadlock that may occur if the "compressor" hibernation
module parameter is accessed during the registration of a new
ieee80211 device (Lizhi Xu)
- Suppress sleeping parent warning in device_pm_add() in the case
when new children are added under a device with the
power.direct_complete set after it has been processed by
device_resume() (Xu Yang)
- Remove needless return in three void functions related to system
wakeup (Zijun Hu)
- Replace deprecated kmap_atomic() with kmap_local_page() in the
hibernation core code (David Reaver)
- Remove unused helper functions related to system sleep (David Alan
Gilbert)
- Clean up s2idle_enter() so it does not lock and unlock CPU offline
in vain and update comments in it (Ulf Hansson)
- Clean up broken white space in dpm_wait_for_children() (Geert
Uytterhoeven)
- Update the cpupower utility to fix lib version-ing in it and memory
leaks in error legs, remove hard-coded values, and implement CPU
physical core querying (Thomas Renninger, John B. Wyatt IV, Shuah
Khan, Yiwei Lin, Zhongqiu Han)"
* tag 'pm-6.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (139 commits)
PM: sleep: Fix bit masking operation
dt-bindings: cpufreq: cpufreq-qcom-hw: Narrow properties on SDX75, SA8775p and SM8650
dt-bindings: cpufreq: cpufreq-qcom-hw: Drop redundant minItems:1
dt-bindings: cpufreq: cpufreq-qcom-hw: Add missing constraint for interrupt-names
dt-bindings: cpufreq: cpufreq-qcom-hw: Add QCS8300 compatible
cpufreq: Init cpufreq only for present CPUs
PM: sleep: Fix handling devices with direct_complete set on errors
cpuidle: Init cpuidle only for present CPUs
PM: clk: Remove unused pm_clk_remove()
PM: sleep: core: Fix indentation in dpm_wait_for_children()
PM: s2idle: Extend comment in s2idle_enter()
PM: s2idle: Drop redundant locks when entering s2idle
PM: sleep: Remove unused pm_generic_ wrappers
cpufreq: tegra186: Share policy per cluster
cpupower: Make lib versioning scheme more obvious and fix version link
PM: EM: Rework the depends on for CONFIG_ENERGY_MODEL
PM: EM: Address RCU-related sparse warnings
cpupower: Implement CPU physical core querying
pm: cpupower: remove hard-coded topology depth values
pm: cpupower: Fix cmd_monitor() error legs to free cpu_topology
...
Currently the CPUFreq core exposes two sysfs attributes that can be used
to query current frequency of a given CPU(s): namely cpuinfo_cur_freq
and scaling_cur_freq. Both provide slightly different view on the
subject and they do come with their own drawbacks.
cpuinfo_cur_freq provides higher precision though at a cost of being
rather expensive. Moreover, the information retrieved via this attribute
is somewhat short lived as frequency can change at any point of time
making it difficult to reason from.
scaling_cur_freq, on the other hand, tends to be less accurate but then
the actual level of precision (and source of information) varies between
architectures making it a bit ambiguous.
The new attribute, cpuinfo_avg_freq, is intended to provide more stable,
distinct interface, exposing an average frequency of a given CPU(s), as
reported by the hardware, over a time frame spanning no more than a few
milliseconds. As it requires appropriate hardware support, this
interface is optional.
Note that under the hood, the new attribute relies on the information
provided by arch_freq_get_on_cpu, which, up to this point, has been
feeding data for scaling_cur_freq attribute, being the source of
ambiguity when it comes to interpretation. This has been amended by
restoring the intended behavior for scaling_cur_freq, with a new
dedicated config option to maintain status quo for those, who may need
it.
CC: Jonathan Corbet <corbet@lwn.net>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Ingo Molnar <mingo@redhat.com>
CC: Borislav Petkov <bp@alien8.de>
CC: Dave Hansen <dave.hansen@linux.intel.com>
CC: H. Peter Anvin <hpa@zytor.com>
CC: Phil Auld <pauld@redhat.com>
CC: x86@kernel.org
CC: linux-doc@vger.kernel.org
Signed-off-by: Beata Michalska <beata.michalska@arm.com>
Reviewed-by: Prasanna Kumar T S M <ptsm@linux.microsoft.com>
Reviewed-by: Sumit Gupta <sumitg@nvidia.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Link: https://lore.kernel.org/r/20250131162439.3843071-3-beata.michalska@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Allow arch_freq_get_on_cpu to return an error for cases when retrieving
current CPU frequency is not possible, whether that being due to lack of
required arch support or due to other circumstances when the current
frequency cannot be determined at given point of time.
Signed-off-by: Beata Michalska <beata.michalska@arm.com>
Reviewed-by: Prasanna Kumar T S M <ptsm@linux.microsoft.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Link: https://lore.kernel.org/r/20250131162439.3843071-2-beata.michalska@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
It is possible to have a scenario where not all cpufreq policies support
boost frequencies. And letting sysfs (or other parts of the kernel)
enable boost feature for that policy isn't correct.
Now that all drivers (that required a change) are updated to set the
policy->boost_supported properly, check this flag before enabling boost
feature for a policy.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
None of the drivers set these attributes directly now, remove the
unnecessary check.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Currently it is left for the individual drivers to set the available and
boost frequencies related attributes in the cpufreq_driver->attr field.
Some drivers provide them, while others don't.
A quick search revealed that only the drivers that set the
policy->freq_table field, enable these attributes. Which makes sense as
well, since the show_available_freqs() helper works only if the
freq_table is present.
In order to simplify drivers, create the relevant sysfs files forcefully
from cpufreq core.
For now, skip adding them twice. This can be removed once all the
drivers are updated.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Commit f994c1cb6c ("cpufreq: Use str_enable_disable()-like helpers") has
already introduced helpers from string_choices.h and replaced ternary
syntax with it. Use str_enable_disable() helper in this line to stay
consistent.
Signed-off-by: Lifeng Zheng <zhenglifeng1@huawei.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Rafael J. Wysocki