include/linux/pagewalk.h

Source file repositories/reference/linux-study-clean/include/linux/pagewalk.h

File Facts

System
Linux kernel
Corpus path
include/linux/pagewalk.h
Extension
.h
Size
7593 bytes
Lines
202
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.

Dependency Surface

Detected Declarations

Annotated Snippet

struct mm_walk_ops {
	int (*pgd_entry)(pgd_t *pgd, unsigned long addr,
			 unsigned long next, struct mm_walk *walk);
	int (*p4d_entry)(p4d_t *p4d, unsigned long addr,
			 unsigned long next, struct mm_walk *walk);
	int (*pud_entry)(pud_t *pud, unsigned long addr,
			 unsigned long next, struct mm_walk *walk);
	int (*pmd_entry)(pmd_t *pmd, unsigned long addr,
			 unsigned long next, struct mm_walk *walk);
	int (*pte_entry)(pte_t *pte, unsigned long addr,
			 unsigned long next, struct mm_walk *walk);
	int (*pte_hole)(unsigned long addr, unsigned long next,
			int depth, struct mm_walk *walk);
	int (*hugetlb_entry)(pte_t *pte, unsigned long hmask,
			     unsigned long addr, unsigned long next,
			     struct mm_walk *walk);
	int (*test_walk)(unsigned long addr, unsigned long next,
			struct mm_walk *walk);
	int (*pre_vma)(unsigned long start, unsigned long end,
		       struct mm_walk *walk);
	void (*post_vma)(struct mm_walk *walk);
	int (*install_pte)(unsigned long addr, unsigned long next,
			   pte_t *ptep, struct mm_walk *walk);
	enum page_walk_lock walk_lock;
};

/*
 * Action for pud_entry / pmd_entry callbacks.
 * ACTION_SUBTREE is the default
 */
enum page_walk_action {
	/* Descend to next level, splitting huge pages if needed and possible */
	ACTION_SUBTREE = 0,
	/* Continue to next entry at this level (ignoring any subtree) */
	ACTION_CONTINUE = 1,
	/* Call again for this entry */
	ACTION_AGAIN = 2
};

/**
 * struct mm_walk - walk_page_range data
 * @ops:	operation to call during the walk
 * @mm:		mm_struct representing the target process of page table walk
 * @pgd:	pointer to PGD; only valid with no_vma (otherwise set to NULL)
 * @vma:	vma currently walked (NULL if walking outside vmas)
 * @action:	next action to perform (see enum page_walk_action)
 * @no_vma:	walk ignoring vmas (vma will always be NULL)
 * @private:	private data for callbacks' usage
 *
 * (see the comment on walk_page_range() for more details)
 */
struct mm_walk {
	const struct mm_walk_ops *ops;
	struct mm_struct *mm;
	pgd_t *pgd;
	struct vm_area_struct *vma;
	enum page_walk_action action;
	bool no_vma;
	void *private;
};

int walk_page_range(struct mm_struct *mm, unsigned long start,
		unsigned long end, const struct mm_walk_ops *ops,
		void *private);
int walk_kernel_page_table_range(unsigned long start,
		unsigned long end, const struct mm_walk_ops *ops,
		pgd_t *pgd, void *private);
int walk_kernel_page_table_range_lockless(unsigned long start,
		unsigned long end, const struct mm_walk_ops *ops,
		pgd_t *pgd, void *private);
int walk_page_range_vma(struct vm_area_struct *vma, unsigned long start,
			unsigned long end, const struct mm_walk_ops *ops,
			void *private);
int walk_page_vma(struct vm_area_struct *vma, const struct mm_walk_ops *ops,
		void *private);
int walk_page_mapping(struct address_space *mapping, pgoff_t first_index,
		      pgoff_t nr, const struct mm_walk_ops *ops,
		      void *private);

typedef int __bitwise folio_walk_flags_t;

/* Walk shared zeropages (small + huge) as well. */
#define FW_ZEROPAGE			((__force folio_walk_flags_t)BIT(0))

enum folio_walk_level {
	FW_LEVEL_PTE,
	FW_LEVEL_PMD,
	FW_LEVEL_PUD,
};

Annotation

Implementation Notes