kernel/linux.git/drivers/cpufreq/cpufreq.c, branch v6.6.141

cpufreq: Initialize cpufreq-based invariance before subsys

2025-10-02T11:42:49+00:00

[ Upstream commit 8ffe28b4e8d8b18cb2f2933410322c24f039d5d6 ] commit 2a6c72738706 ("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: 2a6c72738706 ("cpufreq: Initialize cpufreq-based frequency-invariance later") Signed-off-by: Christian Loehle Signed-off-by: Rafael J. Wysocki Signed-off-by: Sasha Levin

cpufreq: Use the fixed and coherent frequency for scaling capacity

2025-08-28T14:28:42+00:00

commit 599457ba15403037b489fe536266a3d5f9efaed7 upstream. cpuinfo.max_freq can change at runtime because of boost as an example. This implies that the value could be different from the frequency that has been used to compute the capacity of a CPU. The new arch_scale_freq_ref() returns a fixed and coherent frequency that can be used to compute the capacity for a given frequency. [ Also fix a arch_set_freq_scale() newline style wart in . ] Signed-off-by: Vincent Guittot Signed-off-by: Ingo Molnar Tested-by: Lukasz Luba Reviewed-by: Lukasz Luba Acked-by: Viresh Kumar Acked-by: Rafael J. Wysocki Link: https://lore.kernel.org/r/20231211104855.558096-3-vincent.guittot@linaro.org Stable-dep-of: e37617c8e53a ("sched/fair: Fix frequency selection for non-invariant case") Signed-off-by: Wentao Guan Signed-off-by: Greg Kroah-Hartman

cpufreq: Exit governor when failed to start old governor

2025-08-28T14:28:16+00:00

[ Upstream commit 0ae204405095abfbc2d694ee0fbb49bcbbe55c57 ] 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 Link: https://patch.msgid.link/20250709104145.2348017-5-zhenglifeng1@huawei.com Signed-off-by: Rafael J. Wysocki Signed-off-by: Sasha Levin

cpufreq: Init policy->rwsem before it may be possibly used

2025-08-15T10:08:43+00:00

[ Upstream commit d1378d1d7edb3a4c4935a44fe834ae135be03564 ] 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: 67d874c3b2c6 ("cpufreq: Register notifiers with the PM QoS framework") Signed-off-by: Lifeng Zheng Link: https://patch.msgid.link/20250709104145.2348017-3-zhenglifeng1@huawei.com Signed-off-by: Rafael J. Wysocki Signed-off-by: Sasha Levin

cpufreq: Initialize cpufreq-based frequency-invariance later

2025-08-15T10:08:43+00:00

[ Upstream commit 2a6c727387062a2ea79eb6cf5004820cb1b0afe2 ] 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: 874f63531064 ("cpufreq: report whether cpufreq supports Frequency Invariance (FI)") Signed-off-by: Lifeng Zheng Link: https://patch.msgid.link/20250709104145.2348017-2-zhenglifeng1@huawei.com [ rjw: New subject ] Signed-off-by: Rafael J. Wysocki Signed-off-by: Sasha Levin

cpufreq: Fix setting policy limits when frequency tables are used

2025-05-09T07:43:53+00:00

commit b79028039f440e7d2c4df6ab243060c4e3803e84 upstream. Commit 7491cdf46b5c ("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: 7491cdf46b5c ("cpufreq: Avoid using inconsistent policy->min and policy->max") Cc: 5.16+ # 5.16+ Closes: https://lore.kernel.org/linux-pm/aAplED3IA_J0eZN0@linaro.org/ Reported-by: Stephan Gerhold Signed-off-by: Rafael J. Wysocki Tested-by: Stephan Gerhold Reviewed-by: Lifeng Zheng Link: https://patch.msgid.link/5896780.DvuYhMxLoT@rjwysocki.net Signed-off-by: Greg Kroah-Hartman

cpufreq: Avoid using inconsistent policy->min and policy->max

2025-05-09T07:43:53+00:00

commit 7491cdf46b5cbdf123fc84fbe0a07e9e3d7b7620 upstream. 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: 151717690694 ("cpufreq: Make policy min/max hard requirements") Cc: 5.16+ # 5.16+ Signed-off-by: Rafael J. Wysocki Reviewed-by: Christian Loehle Acked-by: Viresh Kumar Link: https://patch.msgid.link/5907080.DvuYhMxLoT@rjwysocki.net Signed-off-by: Greg Kroah-Hartman

cpufreq: Reference count policy in cpufreq_update_limits()

2025-04-25T08:45:54+00:00

commit 9e4e249018d208678888bdf22f6b652728106528 upstream. 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: 5a25e3f7cc53 ("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 Cc: All applicable Signed-off-by: Rafael J. Wysocki Acked-by: Viresh Kumar Link: https://patch.msgid.link/1928789.tdWV9SEqCh@rjwysocki.net [do not use __free(cpufreq_cpu_put) in a backport] Signed-off-by: Marek Marczykowski-GÃ³recki Signed-off-by: Greg Kroah-Hartman

cpufreq: Allow drivers to advertise boost enabled

2024-07-18T11:21:23+00:00

commit 102fa9c4b439ca3bd93d13fb53f5b7592d96a109 upstream. The behavior introduced in commit f37a4d6b4a2c ("cpufreq: Fix per-policy boost behavior on SoCs using cpufreq_boost_set_sw()") sets up the boost policy incorrectly when boost has been enabled by the platform firmware initially even if a driver sets the policy up. This is because policy_has_boost_freq() assumes that there is a frequency table set up by the driver and that the boost frequencies are advertised in that table. This assumption doesn't work for acpi-cpufreq or amd-pstate. Only use this check to enable boost if it's not already enabled instead of also disabling it if alreayd enabled. Fixes: f37a4d6b4a2c ("cpufreq: Fix per-policy boost behavior on SoCs using cpufreq_boost_set_sw()") Link: https://patch.msgid.link/20240626204723.6237-1-mario.limonciello@amd.com Reviewed-by: Sibi Sankar Reviewed-by: Dhruva Gole Acked-by: Viresh Kumar Reviewed-by: Gautham R. Shenoy Suggested-by: Viresh Kumar Suggested-by: Gautham R. Shenoy Signed-off-by: Mario Limonciello Cc: All applicable Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman

cpufreq: exit() callback is optional

2024-06-12T09:11:41+00:00

[ 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 Fixes: 91a12e91dc39 ("cpufreq: Allow light-weight tear down and bring up of CPUs") Fixes: f339f3541701 ("cpufreq: Rearrange locking in cpufreq_remove_dev()") Reported-by: Lizhe Signed-off-by: Rafael J. Wysocki Signed-off-by: Sasha Levin