drivers/firmware/qemu_fw_cfg.c

File Facts

System

Linux kernel

Corpus path

drivers/firmware/qemu_fw_cfg.c

Extension

.c

Size

25743 bytes

Lines

940

Domain

Driver Families

Bucket

drivers/firmware

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/mod_devicetable.h
• linux/platform_device.h
• linux/acpi.h
• linux/slab.h
• linux/io.h
• linux/ioport.h
• uapi/linux/qemu_fw_cfg.h
• linux/delay.h
• linux/crash_dump.h
• linux/vmcore_info.h

Detected Declarations

• struct fw_cfg_sysfs_entry
• struct fw_cfg_sysfs_attribute
• function fw_cfg_sel_endianness
• function fw_cfg_dma_enabled
• function fw_cfg_wait_for_control
• function fw_cfg_dma_transfer
• function fw_cfg_read_blob
• function fw_cfg_write_blob
• function fw_cfg_io_cleanup
• function fw_cfg_do_platform_probe
• function memcmp
• function fw_cfg_showrev
• function fw_cfg_write_vmcoreinfo
• function fw_cfg_sysfs_cache_enlist
• function fw_cfg_sysfs_cache_delist
• function fw_cfg_sysfs_cache_cleanup
• function list_for_each_entry_safe
• function fw_cfg_sysfs_show_size
• function fw_cfg_sysfs_show_key
• function fw_cfg_sysfs_show_name
• function fw_cfg_sysfs_attr_show
• function fw_cfg_sysfs_release_entry
• function fw_cfg_sysfs_read_raw
• function fw_cfg_build_symlink
• function fw_cfg_kset_unregister_recursive
• function fw_cfg_register_file
• function strcmp
• function fw_cfg_register_dir_entries
• function fw_cfg_kobj_cleanup
• function fw_cfg_sysfs_probe
• function fw_cfg_sysfs_remove
• function fw_cfg_cmdline_set
• function fw_cfg_cmdline_get
• function fw_cfg_sysfs_init
• function fw_cfg_sysfs_exit
• module init fw_cfg_sysfs_init

Annotated Snippet

module_init(fw_cfg_sysfs_init);
module_exit(fw_cfg_sysfs_exit);

Annotation

• Immediate include surface: `linux/module.h`, `linux/mod_devicetable.h`, `linux/platform_device.h`, `linux/acpi.h`, `linux/slab.h`, `linux/io.h`, `linux/ioport.h`, `uapi/linux/qemu_fw_cfg.h`.
• Detected declarations: `struct fw_cfg_sysfs_entry`, `struct fw_cfg_sysfs_attribute`, `function fw_cfg_sel_endianness`, `function fw_cfg_dma_enabled`, `function fw_cfg_wait_for_control`, `function fw_cfg_dma_transfer`, `function fw_cfg_read_blob`, `function fw_cfg_write_blob`, `function fw_cfg_io_cleanup`, `function fw_cfg_do_platform_probe`.
• Atlas domain: Driver Families / drivers/firmware.
• 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.