include/linux/pfn.h

File Facts

System

Linux kernel

Corpus path

include/linux/pfn.h

Extension

.h

Size

424 bytes

Lines

16

Domain

Core OS

Bucket

Core Kernel Interface

Inferred role

Core OS: implementation source

Status

source implementation candidate

Why This File Exists

Core operating-system implementation surface: boot, tasks, memory, VFS, syscall-facing interfaces, synchronization, credentials, and isolation.

• Core operating-system implementation surface: boot, tasks, memory, VFS, syscall-facing interfaces, synchronization, credentials, and isolation.

Dependency Surface

• linux/types.h

Detected Declarations

• No top-level syscall, struct, function, initcall, or export declaration detected by the generator.

Annotated Snippet

#ifndef _LINUX_PFN_H_
#define _LINUX_PFN_H_

#ifndef __ASSEMBLY__
#include <linux/types.h>
#endif

#define PFN_ALIGN(x)	(((unsigned long)(x) + (PAGE_SIZE - 1)) & PAGE_MASK)
#define PFN_UP(x)	(((x) + PAGE_SIZE-1) >> PAGE_SHIFT)
#define PFN_DOWN(x)	((x) >> PAGE_SHIFT)
#define PFN_PHYS(x)	((phys_addr_t)(x) << PAGE_SHIFT)
#define PHYS_PFN(x)	((unsigned long)((x) >> PAGE_SHIFT))

#endif

Annotation

• Immediate include surface: `linux/types.h`.
• Atlas domain: Core OS / Core Kernel Interface.
• 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.