drivers/devfreq/governor_userspace.c

File Facts

System

Linux kernel

Corpus path

drivers/devfreq/governor_userspace.c

Extension

.c

Size

3486 bytes

Lines

161

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/slab.h
• linux/device.h
• linux/devfreq.h
• linux/devfreq-governor.h
• linux/kstrtox.h
• linux/pm.h
• linux/mutex.h
• linux/module.h

Detected Declarations

• struct userspace_data
• function devfreq_userspace_func
• function set_freq_store
• function set_freq_show
• function userspace_init
• function userspace_exit
• function devfreq_userspace_handler
• function devfreq_userspace_init
• function devfreq_userspace_exit
• module init devfreq_userspace_init

Annotated Snippet

subsys_initcall(devfreq_userspace_init);

static void __exit devfreq_userspace_exit(void)
{
	int ret;

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

	return;
}
module_exit(devfreq_userspace_exit);
MODULE_DESCRIPTION("DEVFREQ Userspace governor");
MODULE_LICENSE("GPL");

Annotation

• Immediate include surface: `linux/slab.h`, `linux/device.h`, `linux/devfreq.h`, `linux/devfreq-governor.h`, `linux/kstrtox.h`, `linux/pm.h`, `linux/mutex.h`, `linux/module.h`.
• Detected declarations: `struct userspace_data`, `function devfreq_userspace_func`, `function set_freq_store`, `function set_freq_show`, `function userspace_init`, `function userspace_exit`, `function devfreq_userspace_handler`, `function devfreq_userspace_init`, `function devfreq_userspace_exit`, `module init devfreq_userspace_init`.
• 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.