arch/sparc/include/asm/io-unit.h

File Facts

System

Linux kernel

Corpus path

arch/sparc/include/asm/io-unit.h

Extension

.h

Size

2469 bytes

Lines

60

Domain

Architecture Layer

Bucket

arch/sparc

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/spinlock.h
• linux/pgtable.h
• asm/page.h

Detected Declarations

• struct iounit_struct

Annotated Snippet

struct iounit_struct {
	unsigned long		bmap[(IOUNIT_DMA_SIZE >> (PAGE_SHIFT + 3)) / sizeof(unsigned long)];
	spinlock_t		lock;
	iopte_t __iomem		*page_table;
	unsigned long		rotor[3];
	unsigned long		limit[4];
};

#define IOUNIT_BMAP1_START	0x00000000
#define IOUNIT_BMAP1_END	(IOUNIT_DMA_SIZE >> (PAGE_SHIFT + 1))
#define IOUNIT_BMAP2_START	IOUNIT_BMAP1_END
#define IOUNIT_BMAP2_END	IOUNIT_BMAP2_START + (IOUNIT_DMA_SIZE >> (PAGE_SHIFT + 2))
#define IOUNIT_BMAPM_START	IOUNIT_BMAP2_END
#define IOUNIT_BMAPM_END	((IOUNIT_DMA_SIZE - IOUNIT_DVMA_SIZE) >> PAGE_SHIFT)

#endif /* !(_SPARC_IO_UNIT_H) */

Annotation

• Immediate include surface: `linux/spinlock.h`, `linux/pgtable.h`, `asm/page.h`.
• Detected declarations: `struct iounit_struct`.
• Atlas domain: Architecture Layer / arch/sparc.
• 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.