drivers/devfreq/governor_passive.c

File Facts

System

Linux kernel

Corpus path

drivers/devfreq/governor_passive.c

Extension

.c

Size

12342 bytes

Lines

476

Domain

Driver Families

Bucket

drivers/devfreq

Inferred role

Driver Families: exported/initcall integration point

Status

integration implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

• Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.
• Exports symbols or registers init work; inspect boot/module ordering and who consumes the exported contract.
• Uses kernel synchronization; read lock ordering, sleepability, and interrupt context assumptions before translating.
• Allocates kernel memory; connect allocation flags and lifetime to context constraints.
• Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.

Dependency Surface

• linux/module.h
• linux/cpu.h
• linux/cpufreq.h
• linux/cpumask.h
• linux/slab.h
• linux/device.h
• linux/devfreq.h
• linux/devfreq-governor.h
• linux/units.h

Detected Declarations

• struct devfreq_cpu_data
• function get_parent_cpu_data
• function delete_parent_cpu_data
• function list_for_each_entry_safe
• function get_target_freq_by_required_opp
• function get_target_freq_with_cpufreq
• function for_each_online_cpu
• function get_target_freq_with_devfreq
• function devfreq_passive_get_target_freq
• function cpufreq_passive_notifier_call
• function cpufreq_passive_unregister_notifier
• function cpufreq_passive_register_notifier
• function for_each_possible_cpu
• function devfreq_passive_notifier_call
• function devfreq_passive_unregister_notifier
• function devfreq_passive_register_notifier
• function devfreq_passive_event_handler
• function devfreq_passive_init
• function devfreq_passive_exit
• module init devfreq_passive_init

Annotated Snippet

subsys_initcall(devfreq_passive_init);

static void __exit devfreq_passive_exit(void)
{
	int ret;

	ret = devfreq_remove_governor(&devfreq_passive);
	if (ret)
		pr_err("%s: failed remove governor %d\n", __func__, ret);
}
module_exit(devfreq_passive_exit);

MODULE_AUTHOR("Chanwoo Choi <cw00.choi@samsung.com>");
MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
MODULE_DESCRIPTION("DEVFREQ Passive governor");
MODULE_LICENSE("GPL v2");

Annotation

• Immediate include surface: `linux/module.h`, `linux/cpu.h`, `linux/cpufreq.h`, `linux/cpumask.h`, `linux/slab.h`, `linux/device.h`, `linux/devfreq.h`, `linux/devfreq-governor.h`.
• Detected declarations: `struct devfreq_cpu_data`, `function get_parent_cpu_data`, `function delete_parent_cpu_data`, `function list_for_each_entry_safe`, `function get_target_freq_by_required_opp`, `function get_target_freq_with_cpufreq`, `function for_each_online_cpu`, `function get_target_freq_with_devfreq`, `function devfreq_passive_get_target_freq`, `function cpufreq_passive_notifier_call`.
• Atlas domain: Driver Families / drivers/devfreq.
• Implementation status: integration implementation candidate.
• Synchronization appears in or near this file; preserve lock ordering, sleepability, and interrupt-context constraints.

Implementation Notes

• This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
• Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
• Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.