arch/arm/include/asm/dma-iommu.h

File Facts

System

Linux kernel

Corpus path

arch/arm/include/asm/dma-iommu.h

Extension

.h

Size

906 bytes

Lines

37

Domain

Architecture Layer

Bucket

arch/arm

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/mm_types.h
• linux/scatterlist.h
• linux/kref.h

Detected Declarations

• struct dma_iommu_mapping

Annotated Snippet

struct dma_iommu_mapping {
	/* iommu specific data */
	struct iommu_domain	*domain;

	unsigned long		**bitmaps;	/* array of bitmaps */
	unsigned int		nr_bitmaps;	/* nr of elements in array */
	unsigned int		extensions;
	size_t			bitmap_size;	/* size of a single bitmap */
	size_t			bits;		/* per bitmap */
	dma_addr_t		base;

	spinlock_t		lock;
	struct kref		kref;
};

struct dma_iommu_mapping *
arm_iommu_create_mapping(struct device *dev, dma_addr_t base, u64 size);

void arm_iommu_release_mapping(struct dma_iommu_mapping *mapping);

int arm_iommu_attach_device(struct device *dev,
					struct dma_iommu_mapping *mapping);
void arm_iommu_detach_device(struct device *dev);

#endif /* __KERNEL__ */
#endif

Annotation

• Immediate include surface: `linux/mm_types.h`, `linux/scatterlist.h`, `linux/kref.h`.
• Detected declarations: `struct dma_iommu_mapping`.
• Atlas domain: Architecture Layer / arch/arm.
• 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.