path: root/include/asm-generic/pgtable.h

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

#include <linux/pfn.h>

#ifndef __ASSEMBLY__
#ifdef CONFIG_MMU

#include <linux/mm_types.h>
#include <linux/bug.h>
#include <linux/errno.h>

#if 5 - defined(__PAGETABLE_P4D_FOLDED) - defined(__PAGETABLE_PUD_FOLDED) - \
	defined(__PAGETABLE_PMD_FOLDED) != CONFIG_PGTABLE_LEVELS
#error CONFIG_PGTABLE_LEVELS is not consistent with __PAGETABLE_{P4D,PUD,PMD}_FOLDED
#endif

/*
 * On almost all architectures and configurations, 0 can be used as the
 * upper ceiling to free_pgtables(): on many architectures it has the same
 * effect as using TASK_SIZE.  However, there is one configuration which
 * must impose a more careful limit, to avoid freeing kernel pgtables.
 */
#ifndef USER_PGTABLES_CEILING
#define USER_PGTABLES_CEILING	0UL
#endif

#ifndef __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
extern int ptep_set_access_flags(struct vm_area_struct *vma,
				 unsigned long address, pte_t *ptep,
				 pte_t entry, int dirty);
#endif

#ifndef __HAVE_ARCH_PMDP_SET_ACCESS_FLAGS
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
extern int pmdp_set_access_flags(struct vm_area_struct *vma,
				 unsigned long address, pmd_t *pmdp,
				 pmd_t entry, int dirty);
extern int pudp_set_access_flags(struct vm_area_struct *vma,
				 unsigned long address, pud_t *pudp,
				 pud_t entry, int dirty);
#else
static inline int pmdp_set_access_flags(struct vm_area_struct *vma,
					unsigned long address, pmd_t *pmdp,
					pmd_t entry, int dirty)
{
	BUILD_BUG();
	return 0;
}
static inline int pudp_set_access_flags(struct vm_area_struct *vma,
					unsigned long address, pud_t *pudp,
					pud_t entry, int dirty)
{
	BUILD_BUG();
	return 0;
}
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
#endif

#ifndef __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
static inline int ptep_test_and_clear_young(struct vm_area_struct *vma,
					    unsigned long address,
					    pte_t *ptep)
{
	pte_t pte = *ptep;
	int r = 1;
	if (!pte_young(pte))
		r = 0;
	else
		set_pte_at(vma->vm_mm, address, ptep, pte_mkold(pte));
	return r;
}
#endif

#ifndef __HAVE_ARCH_PMDP_TEST_AND_CLEAR_YOUNG
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma,
					    unsigned long address,
					    pmd_t *pmdp)
{
	pmd_t pmd = *pmdp;
	int r = 1;
	if (!pmd_young(pmd))
		r = 0;
	else
		set_pmd_at(vma->vm_mm, address, pmdp, pmd_mkold(pmd));
	return r;
}
#else
static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma,
					    unsigned long address,
					    pmd_t *pmdp)
{
	BUILD_BUG();
	return 0;
}
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
#endif

#ifndef __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
int ptep_clear_flush_young(struct vm_area_struct *vma,
			   unsigned long address, pte_t *ptep);
#endif

#ifndef __HAVE_ARCH_PMDP_CLEAR_YOUNG_FLUSH
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
extern int pmdp_clear_flush_young(struct vm_area_struct *vma,
				  unsigned long address, pmd_t *pmdp);
#else
/*
 * Despite relevant to THP only, this API is called from generic rmap code
 * under PageTransHuge(), hence needs a dummy implementation for !THP
 */
static inline int pmdp_clear_flush_young(struct vm_area_struct *vma,
					 unsigned long address, pmd_t *pmdp)
{
	BUILD_BUG();
	return 0;
}
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
#endif

#ifndef __HAVE_ARCH_PTEP_GET_AND_CLEAR
static inline pte_t ptep_get_and_clear(struct mm_struct *mm,
				       unsigned long address,
				       pte_t *ptep)
{
	pte_t pte = *ptep;
	pte_clear(mm, address, ptep);
	return pte;
}
#endif

#ifdef CONFIG_TRANSPARENT_HUGEPAGE
#ifndef __HAVE_ARCH_PMDP_HUGE_GET_AND_CLEAR
static inline pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm,
					    unsigned long address,
					    pmd_t *pmdp)
{
	pmd_t pmd = *pmdp;
	pmd_clear(pmdp);
	return pmd;
}
#endif /* __HAVE_ARCH_PMDP_HUGE_GET_AND_CLEAR */
#ifndef __HAVE_ARCH_PUDP_HUGE_GET_AND_CLEAR
static inline pud_t pudp_huge_get_and_clear(struct mm_struct *mm,
					    unsigned long address,
					    pud_t *pudp)
{
	pud_t pud = *pudp;

	pud_clea