arch/x86/include/asm/i8259.h

File Facts

System

Linux kernel

Corpus path

arch/x86/include/asm/i8259.h

Extension

.h

Size

2061 bytes

Lines

88

Domain

Architecture Layer

Bucket

arch/x86

Inferred role

Architecture Layer: implementation source

Status

source implementation candidate

Why This File Exists

CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.

• CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.
• Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.

Dependency Surface

• linux/delay.h
• asm/io.h

Detected Declarations

• struct legacy_pic
• function inb_pic
• function outb_pic
• function has_legacy_pic
• function nr_legacy_irqs

Annotated Snippet

struct legacy_pic {
	int nr_legacy_irqs;
	struct irq_chip *chip;
	void (*mask)(unsigned int irq);
	void (*unmask)(unsigned int irq);
	void (*mask_all)(void);
	void (*restore_mask)(void);
	void (*init)(int auto_eoi);
	int (*probe)(void);
	int (*irq_pending)(unsigned int irq);
	void (*make_irq)(unsigned int irq);
};

void legacy_pic_pcat_compat(void);

extern struct legacy_pic *legacy_pic;
extern struct legacy_pic null_legacy_pic;

static inline bool has_legacy_pic(void)
{
	return legacy_pic != &null_legacy_pic;
}

static inline int nr_legacy_irqs(void)
{
	return legacy_pic->nr_legacy_irqs;
}

#endif /* _ASM_X86_I8259_H */

Annotation

• Immediate include surface: `linux/delay.h`, `asm/io.h`.
• Detected declarations: `struct legacy_pic`, `function inb_pic`, `function outb_pic`, `function has_legacy_pic`, `function nr_legacy_irqs`.
• Atlas domain: Architecture Layer / arch/x86.
• Implementation status: source implementation candidate.

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.