[mirror_ubuntu-focal-kernel.git] / include / linux / pagewalk.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_PAGEWALK_H
#define _LINUX_PAGEWALK_H

#include <linux/mm.h>

struct mm_walk;

/**
 * mm_walk_ops - callbacks for walk_page_range
 * @pud_entry:		if set, called for each non-empty PUD (2nd-level) entry
 *			this handler should only handle pud_trans_huge() puds.
 *			the pmd_entry or pte_entry callbacks will be used for
 *			regular PUDs.
 * @pmd_entry:		if set, called for each non-empty PMD (3rd-level) entry
 *			this handler is required to be able to handle
 *			pmd_trans_huge() pmds.  They may simply choose to
 *			split_huge_page() instead of handling it explicitly.
 * @pte_entry:		if set, called for each non-empty PTE (4th-level) entry
 * @pte_hole:		if set, called for each hole at all levels
 * @hugetlb_entry:	if set, called for each hugetlb entry
 * @test_walk:		caller specific callback function to determine whether
 *			we walk over the current vma or not. Returning 0 means
 *			"do page table walk over the current vma", returning
 *			a negative value means "abort current page table walk
 *			right now" and returning 1 means "skip the current vma"
 */
struct mm_walk_ops {
	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,
			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);
};

/**
 * mm_walk - walk_page_range data
 * @ops:	operation to call during the walk
 * @mm:		mm_struct representing the target process of page table walk
 * @vma:	vma currently walked (NULL if walking outside vmas)
 * @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;
	struct vm_area_struct *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_page_vma(struct vm_area_struct *vma, const struct mm_walk_ops *ops,
		void *private);

#endif /* _LINUX_PAGEWALK_H */
Commit	Line	Data
a520110e CH	1	/* SPDX-License-Identifier: GPL-2.0 */
	2	#ifndef _LINUX_PAGEWALK_H
	3	#define _LINUX_PAGEWALK_H
	4
	5	#include <linux/mm.h>
	6
7b86ac33 CH	7	struct mm_walk;
7b86ac33 CH	8
a520110e	9	/**
7b86ac33 CH	10	* mm_walk_ops - callbacks for walk_page_range
	11	* @pud_entry: if set, called for each non-empty PUD (2nd-level) entry
	12	* this handler should only handle pud_trans_huge() puds.
	13	* the pmd_entry or pte_entry callbacks will be used for
	14	* regular PUDs.
	15	* @pmd_entry: if set, called for each non-empty PMD (3rd-level) entry
	16	* this handler is required to be able to handle
	17	* pmd_trans_huge() pmds. They may simply choose to
	18	* split_huge_page() instead of handling it explicitly.
	19	* @pte_entry: if set, called for each non-empty PTE (4th-level) entry
	20	* @pte_hole: if set, called for each hole at all levels
	21	* @hugetlb_entry: if set, called for each hugetlb entry
	22	* @test_walk: caller specific callback function to determine whether
	23	* we walk over the current vma or not. Returning 0 means
	24	* "do page table walk over the current vma", returning
	25	* a negative value means "abort current page table walk
	26	* right now" and returning 1 means "skip the current vma"
a520110e	27	*/
7b86ac33	28	struct mm_walk_ops {
a520110e CH	29	int (pud_entry)(pud_t pud, unsigned long addr,
	30	unsigned long next, struct mm_walk *walk);
	31	int (pmd_entry)(pmd_t pmd, unsigned long addr,
	32	unsigned long next, struct mm_walk *walk);
	33	int (pte_entry)(pte_t pte, unsigned long addr,
	34	unsigned long next, struct mm_walk *walk);
	35	int (*pte_hole)(unsigned long addr, unsigned long next,
	36	struct mm_walk *walk);
	37	int (hugetlb_entry)(pte_t pte, unsigned long hmask,
	38	unsigned long addr, unsigned long next,
	39	struct mm_walk *walk);
	40	int (*test_walk)(unsigned long addr, unsigned long next,
	41	struct mm_walk *walk);
7b86ac33 CH	42	};
	43
	44	/**
	45	* mm_walk - walk_page_range data
	46	* @ops: operation to call during the walk
	47	* @mm: mm_struct representing the target process of page table walk
	48	* @vma: vma currently walked (NULL if walking outside vmas)
	49	* @private: private data for callbacks' usage
	50	*
	51	* (see the comment on walk_page_range() for more details)
	52	*/
	53	struct mm_walk {
	54	const struct mm_walk_ops *ops;
a520110e CH	55	struct mm_struct *mm;
	56	struct vm_area_struct *vma;
	57	void *private;
	58	};
	59
7b86ac33 CH	60	int walk_page_range(struct mm_struct *mm, unsigned long start,
	61	unsigned long end, const struct mm_walk_ops *ops,
	62	void *private);
	63	int walk_page_vma(struct vm_area_struct vma, const struct mm_walk_ops ops,
	64	void *private);
a520110e CH	65
a520110e CH	66	#endif /* _LINUX_PAGEWALK_H */