arch/um/include/asm/pgtable-4level.h

File Facts

System

Linux kernel

Corpus path

arch/um/include/asm/pgtable-4level.h

Extension

.h

Size

2981 bytes

Lines

111

Domain

Architecture Layer

Bucket

arch/um

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.

Dependency Surface

• asm-generic/pgtable-nop4d.h

Detected Declarations

• function printk
• function pgd_mkuptodate
• function pud_clear
• function p4d_clear
• function pte_pfn
• function pfn_pmd

Annotated Snippet

static inline void pgd_mkuptodate(pgd_t pgd) { pgd_val(pgd) &= ~_PAGE_NEEDSYNC; }

#define set_pmd(pmdptr, pmdval) (*(pmdptr) = (pmdval))

static inline void pud_clear (pud_t *pud)
{
	set_pud(pud, __pud(_PAGE_NEEDSYNC));
}

static inline void p4d_clear (p4d_t *p4d)
{
	set_p4d(p4d, __p4d(_PAGE_NEEDSYNC));
}

#define pud_page(pud) phys_to_page(pud_val(pud) & PAGE_MASK)
#define pud_pgtable(pud) ((pmd_t *) __va(pud_val(pud) & PAGE_MASK))

#define p4d_page(p4d) phys_to_page(p4d_val(p4d) & PAGE_MASK)
#define p4d_pgtable(p4d) ((pud_t *) __va(p4d_val(p4d) & PAGE_MASK))

static inline unsigned long pte_pfn(pte_t pte)
{
	return phys_to_pfn(pte_val(pte));
}

static inline pmd_t pfn_pmd(unsigned long page_nr, pgprot_t pgprot)
{
	return __pmd((page_nr << PAGE_SHIFT) | pgprot_val(pgprot));
}

#endif

Annotation

• Immediate include surface: `asm-generic/pgtable-nop4d.h`.
• Detected declarations: `function printk`, `function pgd_mkuptodate`, `function pud_clear`, `function p4d_clear`, `function pte_pfn`, `function pfn_pmd`.
• Atlas domain: Architecture Layer / arch/um.
• 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.