pgtable.h (revision 568b4576b2739d8e84509e2f7bb68d12a8b0a764) - OpenGrok cross reference for /linux/arch/x86/include/asm/pgtable.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_X86_PGTABLE_H
#define _ASM_X86_PGTABLE_H

#include <linux/mem_encrypt.h>
#include <asm/page.h>
#include <asm/pgtable_types.h>

/*
 * Macro to mark a page protection value as UC-
 */
#define pgprot_noncached(prot)						\
	((boot_cpu_data.x86 > 3)					\
	 ? (__pgprot(pgprot_val(prot) |					\
		     cachemode2protval(_PAGE_CACHE_MODE_UC_MINUS)))	\
	 : (prot))

#ifndef __ASSEMBLER__
#include <linux/spinlock.h>
#include <asm/x86_init.h>
#include <asm/pkru.h>
#include <asm/fpu/api.h>
#include <asm/coco.h>
#include <asm-generic/pgtable_uffd.h>
#include <linux/page_table_check.h>

extern pgd_t early_top_pgt[PTRS_PER_PGD];
bool __init __early_make_pgtable(unsigned long address, pmdval_t pmd);

struct seq_file;
void ptdump_walk_pgd_level(struct seq_file *m, struct mm_struct *mm);
void ptdump_walk_pgd_level_debugfs(struct seq_file *m, struct mm_struct *mm,
				   bool user);
bool ptdump_walk_pgd_level_checkwx(void);
#define ptdump_check_wx ptdump_walk_pgd_level_checkwx
void ptdump_walk_user_pgd_level_checkwx(void);

/*
 * Macros to add or remove encryption attribute
 */
#define pgprot_encrypted(prot)	__pgprot(cc_mkenc(pgprot_val(prot)))
#define pgprot_decrypted(prot)	__pgprot(cc_mkdec(pgprot_val(prot)))

#ifdef CONFIG_DEBUG_WX
#define debug_checkwx_user()	ptdump_walk_user_pgd_level_checkwx()
#else
#define debug_checkwx_user()	do { } while (0)
#endif

extern spinlock_t pgd_lock;
extern struct list_head pgd_list;

struct mm_struct *pgd_page_get_mm(struct ptdesc *pt);

extern pmdval_t early_pmd_flags;

#ifdef CONFIG_PARAVIRT_XXL
#include <asm/paravirt.h>
#else  /* !CONFIG_PARAVIRT_XXL */
#define set_pte(ptep, pte)		native_set_pte(ptep, pte)

#define set_pte_atomic(ptep, pte)					\
	native_set_pte_atomic(ptep, pte)

#define set_pmd(pmdp, pmd)		native_set_pmd(pmdp, pmd)

#ifndef __PAGETABLE_P4D_FOLDED
#define set_pgd(pgdp, pgd)		native_set_pgd(pgdp, pgd)
#define pgd_clear(pgdp)			\
do {					\
	if (pgtable_l5_enabled())	\
		native_pgd_clear(pgdp);	\
} while (0)
#endif

#ifndef set_p4d
# define set_p4d(p4dp, p4d)		native_set_p4d(p4dp, p4d)
#endif

#ifndef __PAGETABLE_PUD_FOLDED
#define p4d_clear(p4d)			native_p4d_clear(p4d)
#endif

#ifndef set_pud
# define set_pud(pudp, pud)		native_set_pud(pudp, pud)
#endif

#ifndef __PAGETABLE_PUD_FOLDED
#define pud_clear(pud)			native_pud_clear(pud)
#endif

#define pte_clear(mm, addr, ptep)	native_pte_clear(mm, addr, ptep)
#define pmd_clear(pmd)			native_pmd_clear(pmd)

#define pgd_val(x)	native_pgd_val(x)
#define __pgd(x)	native_make_pgd(x)

#ifndef __PAGETABLE_P4D_FOLDED
#define p4d_val(x)	native_p4d_val(x)
#define __p4d(x)	native_make_p4d(x)
#endif

#ifndef __PAGETABLE_PUD_FOLDED
#define pud_val(x)	native_pud_val(x)
#define __pud(x)	native_make_pud(x)
#endif

#ifndef __PAGETABLE_PMD_FOLDED
#define pmd_val(x)	native_pmd_val(x)
#define __pmd(x)	native_make_pmd(x)
#endif

#define pte_val(x)	native_pte_val(x)
#define __pte(x)	native_make_pte(x)

#define arch_end_context_switch(prev)	do {} while(0)
static inline void arch_flush_lazy_mmu_mode(void) {}
#endif	/* CONFIG_PARAVIRT_XXL */

static inline pmd_t pmd_set_flags(pmd_t pmd, pmdval_t set)
{
	pmdval_t v = native_pmd_val(pmd);

	return native_make_pmd(v | set);
}

static inline pmd_t pmd_clear_flags(pmd_t pmd, pmdval_t clear)
{
	pmdval_t v = native_pmd_val(pmd);

	return native_make_pmd(v & ~clear);
}

static inline pud_t pud_set_flags(pud_t pud, pudval_t set)
{
	pudval_t v = native_pud_val(pud);

	return native_make_pud(v | set);
}

static inline pud_t pud_clear_flags(pud_t pud, pudval_t clear)
{
	pudval_t v = native_pud_val(pud);

	return native_make_pud(v & ~clear);
}

/*
 * The following only work if pte_present() is true.
 * Undefined behaviour if not..
 */
static inline bool pte_dirty(pte_t pte)
{
	return pte_flags(pte) & _PAGE_DIRTY_BITS;
}

static inline bool pte_shstk(pte_t pte)
{
	return cpu_feature_enabled(X86_FEATURE_SHSTK) &&
	       (pte_flags(pte) & (_PAGE_RW | _PAGE_DIRTY)) == _PAGE_DIRTY;
}

static inline int pte_young(pte_t pte)
{
	return pte_flags(pte) & _PAGE_ACCESSED;
}

static inline bool pte_decrypted(pte_t pte)
{
	return cc_mkdec(pte_val(pte)) == pte_val(pte);
}

#define pmd_dirty pmd_dirty
static inline bool pmd_dirty(pmd_t pmd)
{
	return pmd_flags(pmd) & _PAGE_DIRTY_BITS;
}

static inline bool pmd_shstk(pmd_t pmd)
{
	return cpu_feature_enabled(X86_FEATURE_SHSTK) &&
	       (pmd_flags(pmd) & (_PAGE_RW | _PAGE_DIRTY | _PAGE_PSE)) ==
	       (_PAGE_DIRTY | _PAGE_PSE);
}

#define pmd_young pmd_young
static inline int pmd_young(pmd_t pmd)
{
	return pmd_flags(pmd) & _PAGE_ACCESSED;
}

static inline bool pud_dirty(pud_t pud)
{
	return pud_flags(pud) & _PAGE_DIRTY_BITS;
}

static inline int pud_young(pud_t pud)
{
	return pud_flags(pud) & _PAGE_ACCESSED;
}

static inline bool pud_shstk(pud_t pud)
{
	return cpu_feature_enabled(X86_FEATURE_SHSTK) &&
	       (pud_flags(pud) & (_PAGE_RW | _PAGE_DIRTY | _PAGE_PSE)) ==
	       (_PAGE_DIRTY | _PAGE_PSE);
}

static inline int pte_write(pte_t pte)
{
	/*
	 * Shadow stack pages are logically writable, but do not have
	 * _PAGE_RW.  Check for them separately from _PAGE_RW itself.
	 */
	return (pte_flags(pte) & _PAGE_RW) || pte_shstk(pte);
}

#define pmd_write pmd_write
static inline int pmd_write(pmd_t pmd)
{
	/*
	 * Shadow stack pages are logically writable, but do not have
	 * _PAGE_RW.  Check for them separately from _PAGE_RW itself.
	 */
	return (pmd_flags(pmd) & _PAGE_RW) || pmd_shstk(pmd);
}

#define pud_write pud_write
static inline int pud_write(pud_t pud)
{
	return pud_flags(pud) & _PAGE_RW;
}

static inline int pte_huge(pte_t pte)
{
	return pte_flags(pte) & _PAGE_PSE;
}

static inline int pte_global(pte_t pte)
{
	return pte_flags(pte) & _PAGE_GLOBAL;
}

static inline int pte_exec(pte_t pte)
{
	return !(pte_flags(pte) & _PAGE_NX);
}

static inline int pte_special(pte_t pte)
{
	return pte_flags(pte) & _PAGE_SPECIAL;
}

/* Entries that were set to PROT_NONE are inverted */

static inline u64 protnone_mask(u64 val);

#define PFN_PTE_SHIFT	PAGE_SHIFT

static inline unsigned long pte_pfn(pte_t pte)
{
	phys_addr_t pfn = pte_val(pte);
	pfn ^= protnone_mask(pfn);
	return (pfn & PTE_PFN_MASK) >> PAGE_SHIFT;
}

static inline unsigned long pmd_pfn(pmd_t pmd)
{
	phys_addr_t pfn = pmd_val(pmd);
	pfn ^= protnone_mask(pfn);
	return (pfn & pmd_pfn_mask(pmd)) >> PAGE_SHIFT;
}

#define pud_pfn pud_pfn
static inline unsigned long pud_pfn(pud_t pud)
{
	phys_addr_t pfn = pud_val(pud);
	pfn ^= protnone_mask(pfn);
	return (pfn & pud_pfn_mask(pud)) >> PAGE_SHIFT;
}

static inline unsigned long p4d_pfn(p4d_t p4d)
{
	return (p4d_val(p4d) & p4d_pfn_mask(p4d)) >> PAGE_SHIFT;
}

static inline unsigned long pgd_pfn(pgd_t pgd)
{
	return (pgd_val(pgd) & PTE_PFN_MASK) >> PAGE_SHIFT;
}

#define pte_page(pte)	pfn_to_page(pte_pfn(pte))

#define pmd_leaf pmd_leaf
static inline bool pmd_leaf(pmd_t pte)
{
	return pmd_flags(pte) & _PAGE_PSE;
}

#ifdef CONFIG_TRANSPARENT_HUGEPAGE
static inline int pmd_trans_huge(pmd_t pmd)
{
	return (pmd_val(pmd) & _PAGE_PSE) == _PAGE_PSE;
}

#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
static inline int pud_trans_huge(pud_t pud)
{
	return (pud_val(pud) & _PAGE_PSE) == _PAGE_PSE;
}
#endif

#define has_transparent_hugepage has_transparent_hugepage
static inline int has_transparent_hugepage(void)
{
	return boot_cpu_has(X86_FEATURE_PSE);
}

#ifdef CONFIG_ARCH_SUPPORTS_PMD_PFNMAP
static inline bool pmd_special(pmd_t pmd)
{
	return pmd_flags(pmd) & _PAGE_SPECIAL;
}

static inline pmd_t pmd_mkspecial(pmd_t pmd)
{
	return pmd_set_flags(pmd, _PAGE_SPECIAL);
}
#endif	/* CONFIG_ARCH_SUPPORTS_PMD_PFNMAP */

#ifdef CONFIG_ARCH_SUPPORTS_PUD_PFNMAP
static inline bool pud_special(pud_t pud)
{
	return pud_flags(pud) & _PAGE_SPECIAL;
}

static inline pud_t pud_mkspecial(pud_t pud)
{
	return pud_set_flags(pud, _PAGE_SPECIAL);
}
#endif	/* CONFIG_ARCH_SUPPORTS_PUD_PFNMAP */
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */

static inline pte_t pte_set_flags(pte_t pte, pteval_t set)
{
	pteval_t v = native_pte_val(pte);

	return native_make_pte(v | set);
}

static inline pte_t pte_clear_flags(pte_t pte, pteval_t clear)
{
	pteval_t v = native_pte_val(pte);

	return native_make_pte(v & ~clear);
}

/*
 * Write protection operations can result in Dirty=1,Write=0 PTEs. But in the
 * case of X86_FEATURE_USER_SHSTK, these PTEs denote shadow stack memory. So
 * when creating dirty, write-protected memory, a software bit is used:
 * _PAGE_BIT_SAVED_DIRTY. The following functions take a PTE and transition the
 * Dirty bit to SavedDirty, and vice-vesra.
 *
 * This shifting is only done if needed. In the case of shifting
 * Dirty->SavedDirty, the condition is if the PTE is Write=0. In the case of
 * shifting SavedDirty->Dirty, the condition is Write=1.
 */
static inline pgprotval_t mksaveddirty_shift(pgprotval_t v)
{
	pgprotval_t cond = (~v >> _PAGE_BIT_RW) & 1;

	v |= ((v >> _PAGE_BIT_DIRTY) & cond) << _PAGE_BIT_SAVED_DIRTY;
	v &= ~(cond << _PAGE_BIT_DIRTY);

	return v;
}

static inline pgprotval_t clear_saveddirty_shift(pgprotval_t v)
{
	pgprotval_t cond = (v >> _PAGE_BIT_RW) & 1;

	v |= ((v >> _PAGE_BIT_SAVED_DIRTY) & cond) << _PAGE_BIT_DIRTY;
	v &= ~(cond << _PAGE_BIT_SAVED_DIRTY);

	return v;
}

static inline pte_t pte_mksaveddirty(pte_t pte)
{
	pteval_t v = native_pte_val(pte);

	v = mksaveddirty_shift(v);
	return native_make_pte(v);
}

static inline pte_t pte_clear_saveddirty(pte_t pte)
{
	pteval_t v = native_pte_val(pte);

	v = clear_saveddirty_shift(v);
	return native_make_pte(v);
}

static inline pte_t pte_wrprotect(pte_t pte)
{
	pte = pte_clear_flags(pte, _PAGE_RW);

	/*
	 * Blindly clearing _PAGE_RW might accidentally create
	 * a shadow stack PTE (Write=0,Dirty=1). Move the hardware
	 * dirty value to the software bit, if present.
	 */
	return pte_mksaveddirty(pte);
}

#ifdef CONFIG_HAVE_ARCH_USERFAULTFD_WP
static inline int pte_uffd(pte_t pte)
{
	return pte_flags(pte) & _PAGE_UFFD;
}

static inline pte_t pte_mkuffd(pte_t pte)
{
	return pte_wrprotect(pte_set_flags(pte, _PAGE_UFFD));
}

static inline pte_t pte_clear_uffd(pte_t pte)
{
	return pte_clear_flags(pte, _PAGE_UFFD);
}
#endif /* CONFIG_HAVE_ARCH_USERFAULTFD_WP */

static inline pte_t pte_mkclean(pte_t pte)
{
	return pte_clear_flags(pte, _PAGE_DIRTY_BITS);
}

static inline pte_t pte_mkold(pte_t pte)
{
	return pte_clear_flags(pte, _PAGE_ACCESSED);
}

static inline pte_t pte_mkexec(pte_t pte)
{
	return pte_clear_flags(pte, _PAGE_NX);
}

static inline pte_t pte_mkdirty(pte_t pte)
{
	pte = pte_set_flags(pte, _PAGE_DIRTY | _PAGE_SOFT_DIRTY);

	return pte_mksaveddirty(pte);
}

static inline pte_t pte_mkwrite_shstk(pte_t pte)
{
	pte = pte_clear_flags(pte, _PAGE_RW);

	return pte_set_flags(pte, _PAGE_DIRTY);
}

static inline pte_t pte_mkyoung(pte_t pte)
{
	return pte_set_flags(pte, _PAGE_ACCESSED);
}

static inline pte_t pte_mkwrite_novma(pte_t pte)
{
	return pte_set_flags(pte, _PAGE_RW);
}

struct vm_area_struct;
pte_t pte_mkwrite(pte_t pte, struct vm_area_struct *vma);
#define pte_mkwrite pte_mkwrite

static inline pte_t pte_mkhuge(pte_t pte)
{
	return pte_set_flags(pte, _PAGE_PSE);
}

static inline pte_t pte_clrhuge(pte_t pte)
{
	return pte_clear_flags(pte, _PAGE_PSE);
}

static inline pte_t pte_mkglobal(pte_t pte)
{
	return pte_set_flags(pte, _PAGE_GLOBAL);
}

static inline pte_t pte_clrglobal(pte_t pte)
{
	return pte_clear_flags(pte, _PAGE_GLOBAL);
}

static inline pte_t pte_mkspecial(pte_t pte)
{
	return pte_set_flags(pte, _PAGE_SPECIAL);
}

/* See comments above mksaveddirty_shift() */
static inline pmd_t pmd_mksaveddirty(pmd_t pmd)
{
	pmdval_t v = native_pmd_val(pmd);

	v = mksaveddirty_shift(v);
	return native_make_pmd(v);
}

/* See comments above mksaveddirty_shift() */
static inline pmd_t pmd_clear_saveddirty(pmd_t pmd)
{
	pmdval_t v = native_pmd_val(pmd);

	v = clear_saveddirty_shift(v);
	return native_make_pmd(v);
}

static inline pmd_t pmd_wrprotect(pmd_t pmd)
{
	pmd = pmd_clear_flags(pmd, _PAGE_RW);

	/*
	 * Blindly clearing _PAGE_RW might accidentally create
	 * a shadow stack PMD (RW=0, Dirty=1). Move the hardware
	 * dirty value to the software bit.
	 */
	return pmd_mksaveddirty(pmd);
}

#ifdef CONFIG_HAVE_ARCH_USERFAULTFD_WP
static inline int pmd_uffd(pmd_t pmd)
{
	return pmd_flags(pmd) & _PAGE_UFFD;
}

static inline pmd_t pmd_mkuffd(pmd_t pmd)
{
	return pmd_wrprotect(pmd_set_flags(pmd, _PAGE_UFFD));
}

static inline pmd_t pmd_clear_uffd(pmd_t pmd)
{
	return pmd_clear_flags(pmd, _PAGE_UFFD);
}
#endif /* CONFIG_HAVE_ARCH_USERFAULTFD_WP */

static inline pmd_t pmd_mkold(pmd_t pmd)
{
	return pmd_clear_flags(pmd, _PAGE_ACCESSED);
}

static inline pmd_t pmd_mkclean(pmd_t pmd)
{
	return pmd_clear_flags(pmd, _PAGE_DIRTY_BITS);
}

static inline pmd_t pmd_mkdirty(pmd_t pmd)
{
	pmd = pmd_set_flags(pmd, _PAGE_DIRTY | _PAGE_SOFT_DIRTY);

	return pmd_mksaveddirty(pmd);
}

static inline pmd_t pmd_mkwrite_shstk(pmd_t pmd)
{
	pmd = pmd_clear_flags(pmd, _PAGE_RW);

	return pmd_set_flags(pmd, _PAGE_DIRTY);
}

static inline pmd_t pmd_mkhuge(pmd_t pmd)
{
	return pmd_set_flags(pmd, _PAGE_PSE);
}

static inline pmd_t pmd_mkyoung(pmd_t pmd)
{
	return pmd_set_flags(pmd, _PAGE_ACCESSED);
}

static inline pmd_t pmd_mkwrite_novma(pmd_t pmd)
{
	return pmd_set_flags(pmd, _PAGE_RW);
}

pmd_t pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma);
#define pmd_mkwrite pmd_mkwrite

/* See comments above mksaveddirty_shift() */
static inline pud_t pud_mksaveddirty(pud_t pud)
{
	pudval_t v = native_pud_val(pud);

	v = mksaveddirty_shift(v);
	return native_make_pud(v);
}

/* See comments above mksaveddirty_shift() */
static inline pud_t pud_clear_saveddirty(pud_t pud)
{
	pudval_t v = native_pud_val(pud);

	v = clear_saveddirty_shift(v);
	return native_make_pud(v);
}

static inline pud_t pud_mkold(pud_t pud)
{
	return pud_clear_flags(pud, _PAGE_ACCESSED);
}

static inline pud_t pud_mkclean(pud_t pud)
{
	return pud_clear_flags(pud, _PAGE_DIRTY_BITS);
}

static inline pud_t pud_wrprotect(pud_t pud)
{
	pud = pud_clear_flags(pud, _PAGE_RW);

	/*
	 * Blindly clearing _PAGE_RW might accidentally create
	 * a shadow stack PUD (RW=0, Dirty=1). Move the hardware
	 * dirty value to the software bit.
	 */
	return pud_mksaveddirty(pud);
}

static inline pud_t pud_mkdirty(pud_t pud)
{
	pud = pud_set_flags(pud, _PAGE_DIRTY | _PAGE_SOFT_DIRTY);

	return pud_mksaveddirty(pud);
}

static inline pud_t pud_mkhuge(pud_t pud)
{
	return pud_set_flags(pud, _PAGE_PSE);
}

static inline pud_t pud_mkyoung(pud_t pud)
{
	return pud_set_flags(pud, _PAGE_ACCESSED);
}

static inline pud_t pud_mkwrite(pud_t pud)
{
	pud = pud_set_flags(pud, _PAGE_RW);

	return pud_clear_saveddirty(pud);
}

#ifdef CONFIG_HAVE_ARCH_SOFT_DIRTY
static inline int pte_soft_dirty(pte_t pte)
{
	return pte_flags(pte) & _PAGE_SOFT_DIRTY;
}

static inline int pmd_soft_dirty(pmd_t pmd)
{
	return pmd_flags(pmd) & _PAGE_SOFT_DIRTY;
}

static inline int pud_soft_dirty(pud_t pud)
{
	return pud_flags(pud) & _PAGE_SOFT_DIRTY;
}

static inline pte_t pte_mksoft_dirty(pte_t pte)
{
	return pte_set_flags(pte, _PAGE_SOFT_DIRTY);
}

static inline pmd_t pmd_mksoft_dirty(pmd_t pmd)
{
	return pmd_set_flags(pmd, _PAGE_SOFT_DIRTY);
}

static inline pud_t pud_mksoft_dirty(pud_t pud)
{
	return pud_set_flags(pud, _PAGE_SOFT_DIRTY);
}

static inline pte_t pte_clear_soft_dirty(pte_t pte)
{
	return pte_clear_flags(pte, _PAGE_SOFT_DIRTY);
}

static inline pmd_t pmd_clear_soft_dirty(pmd_t pmd)
{
	return pmd_clear_flags(pmd, _PAGE_SOFT_DIRTY);
}

static inline pud_t pud_clear_soft_dirty(pud_t pud)
{
	return pud_clear_flags(pud, _PAGE_SOFT_DIRTY);
}

#endif /* CONFIG_HAVE_ARCH_SOFT_DIRTY */

/*
 * Mask out unsupported bits in a present pgprot.  Non-present pgprots
 * can use those bits for other purposes, so leave them be.
 */
static inline pgprotval_t massage_pgprot(pgprot_t pgprot)
{
	pgprotval_t protval = pgprot_val(pgprot);

	if (protval & _PAGE_PRESENT)
		protval &= __supported_pte_mask;

	return protval;
}

static inline pgprotval_t check_pgprot(pgprot_t pgprot)
{
	pgprotval_t massaged_val = massage_pgprot(pgprot);

	/* mmdebug.h can not be included here because of dependencies */
#ifdef CONFIG_DEBUG_VM
	WARN_ONCE(pgprot_val(pgprot) != massaged_val,
		  "attempted to set unsupported pgprot: %016llx "
		  "bits: %016llx supported: %016llx\n",
		  (u64)pgprot_val(pgprot),
		  (u64)pgprot_val(pgprot) ^ massaged_val,
		  (u64)__supported_pte_mask);
#endif

	return massaged_val;
}

static inline pte_t pfn_pte(unsigned long page_nr, pgprot_t pgprot)
{
	phys_addr_t pfn = (phys_addr_t)page_nr << PAGE_SHIFT;
	/* This bit combination is used to mark shadow stacks */
	WARN_ON_ONCE((pgprot_val(pgprot) & (_PAGE_DIRTY | _PAGE_RW)) ==
			_PAGE_DIRTY);
	pfn ^= protnone_mask(pgprot_val(pgprot));
	pfn &= PTE_PFN_MASK;
	return __pte(pfn | check_pgprot(pgprot));
}

static inline pmd_t pfn_pmd(unsigned long page_nr, pgprot_t pgprot)
{
	phys_addr_t pfn = (phys_addr_t)page_nr << PAGE_SHIFT;
	pfn ^= protnone_mask(pgprot_val(pgprot));
	pfn &= PHYSICAL_PMD_PAGE_MASK;
	return __pmd(pfn | check_pgprot(pgprot));
}

static inline pud_t pfn_pud(unsigned long page_nr, pgprot_t pgprot)
{
	phys_addr_t pfn = (phys_addr_t)page_nr << PAGE_SHIFT;
	pfn ^= protnone_mask(pgprot_val(pgprot));
	pfn &= PHYSICAL_PUD_PAGE_MASK;
	return __pud(pfn | check_pgprot(pgprot));
}

static inline pmd_t pmd_mkinvalid(pmd_t pmd)
{
	return pfn_pmd(pmd_pfn(pmd),
		      __pgprot(pmd_flags(pmd) & ~(_PAGE_PRESENT|_PAGE_PROTNONE)));
}

static inline pud_t pud_mkinvalid(pud_t pud)
{
	return pfn_pud(pud_pfn(pud),
		       __pgprot(pud_flags(pud) & ~(_PAGE_PRESENT|_PAGE_PROTNONE)));
}

static inline u64 flip_protnone_guard(u64 oldval, u64 val, u64 mask);

static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
{
	pteval_t val = pte_val(pte), oldval = val;
	pte_t pte_result;

	/*
	 * Chop off the NX bit (if present), and add the NX portion of
	 * the newprot (if present):
	 */
	val &= _PAGE_CHG_MASK;
	val |= check_pgprot(newprot) & ~_PAGE_CHG_MASK;
	val = flip_protnone_guard(oldval, val, PTE_PFN_MASK);

	pte_result = __pte(val);

	/*
	 * To avoid creating Write=0,Dirty=1 PTEs, pte_modify() needs to avoid:
	 *  1. Marking Write=0 PTEs Dirty=1
	 *  2. Marking Dirty=1 PTEs Write=0
	 *
	 * The first case cannot happen because the _PAGE_CHG_MASK will filter
	 * out any Dirty bit passed in newprot. Handle the second case by
	 * going through the mksaveddirty exercise. Only do this if the old
	 * value was Write=1 to avoid doing this on Shadow Stack PTEs.
	 */
	if (oldval & _PAGE_RW)
		pte_result = pte_mksaveddirty(pte_result);
	else
		pte_result = pte_clear_saveddirty(pte_result);

	return pte_result;
}

static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
{
	pmdval_t val = pmd_val(pmd), oldval = val;
	pmd_t pmd_result;

	val &= _HPAGE_CHG_MASK;
	val |= check_pgprot(newprot) & ~_HPAGE_CHG_MASK;
	val = flip_protnone_guard(oldval, val, PHYSICAL_PMD_PAGE_MASK);

	pmd_result = __pmd(val);

	/*
	 * Avoid creating shadow stack PMD by accident.  See comment in
	 * pte_modify().
	 */
	if (oldval & _PAGE_RW)
		pmd_result = pmd_mksaveddirty(pmd_result);
	else
		pmd_result = pmd_clear_saveddirty(pmd_result);

	return pmd_result;
}

static inline pud_t pud_modify(pud_t pud, pgprot_t newprot)
{
	pudval_t val = pud_val(pud), oldval = val;
	pud_t pud_result;

	val &= _HPAGE_CHG_MASK;
	val |= check_pgprot(newprot) & ~_HPAGE_CHG_MASK;
	val = flip_protnone_guard(oldval, val, PHYSICAL_PUD_PAGE_MASK);

	pud_result = __pud(val);

	/*
	 * Avoid creating shadow stack PUD by accident.  See comment in
	 * pte_modify().
	 */
	if (oldval & _PAGE_RW)
		pud_result = pud_mksaveddirty(pud_result);
	else
		pud_result = pud_clear_saveddirty(pud_result);

	return pud_result;
}

/*
 * mprotect needs to preserve PAT and encryption bits when updating
 * vm_page_prot
 */
#define pgprot_modify pgprot_modify
static inline pgprot_t pgprot_modify(pgprot_t oldprot, pgprot_t newprot)
{
	pgprotval_t preservebits = pgprot_val(oldprot) & _PAGE_CHG_MASK;
	pgprotval_t addbits = pgprot_val(newprot) & ~_PAGE_CHG_MASK;
	return __pgprot(preservebits | addbits);
}

#define pte_pgprot(x) __pgprot(pte_flags(x))
#define pmd_pgprot(x) __pgprot(pmd_flags(x))
#define pud_pgprot(x) __pgprot(pud_flags(x))
#define p4d_pgprot(x) __pgprot(p4d_flags(x))

#define canon_pgprot(p) __pgprot(massage_pgprot(p))

static inline int is_new_memtype_allowed(u64 paddr, unsigned long size,
					 enum page_cache_mode pcm,
					 enum page_cache_mode new_pcm)
{
	/*
	 * PAT type is always WB for untracked ranges, so no need to check.
	 */
	if (x86_platform.is_untracked_pat_range(paddr, paddr + size))
		return 1;

	/*
	 * Certain new memtypes are not allowed with certain
	 * requested memtype:
	 * - request is uncached, return cannot be write-back
	 * - request is write-combine, return cannot be write-back
	 * - request is write-through, return cannot be write-back
	 * - request is write-through, return cannot be write-combine
	 */
	if ((pcm == _PAGE_CACHE_MODE_UC_MINUS &&
	     new_pcm == _PAGE_CACHE_MODE_WB) ||
	    (pcm == _PAGE_CACHE_MODE_WC &&
	     new_pcm == _PAGE_CACHE_MODE_WB) ||
	    (pcm == _PAGE_CACHE_MODE_WT &&
	     new_pcm == _PAGE_CACHE_MODE_WB) ||
	    (pcm == _PAGE_CACHE_MODE_WT &&
	     new_pcm == _PAGE_CACHE_MODE_WC)) {
		return 0;
	}

	return 1;
}

pmd_t *populate_extra_pmd(unsigned long vaddr);
pte_t *populate_extra_pte(unsigned long vaddr);

#ifdef CONFIG_MITIGATION_PAGE_TABLE_ISOLATION
pgd_t __pti_set_user_pgtbl(pgd_t *pgdp, pgd_t pgd);

/*
 * Take a PGD location (pgdp) and a pgd value that needs to be set there.
 * Populates the user and returns the resulting PGD that must be set in
 * the kernel copy of the page tables.
 */
static inline pgd_t pti_set_user_pgtbl(pgd_t *pgdp, pgd_t pgd)
{
	if (!cpu_feature_enabled(X86_FEATURE_PTI))
		return pgd;
	return __pti_set_user_pgtbl(pgdp, pgd);
}
#else   /* CONFIG_MITIGATION_PAGE_TABLE_ISOLATION */
static inline pgd_t pti_set_user_pgtbl(pgd_t *pgdp, pgd_t pgd)
{
	return pgd;
}
#endif  /* CONFIG_MITIGATION_PAGE_TABLE_ISOLATION */

#endif	/* __ASSEMBLER__ */


#ifdef CONFIG_X86_32
# include <asm/pgtable_32.h>
#else
# include <asm/pgtable_64.h>
#endif

#ifndef __ASSEMBLER__
#include <linux/mm_types.h>
#include <linux/mmdebug.h>
#include <linux/log2.h>
#include <asm/fixmap.h>

static inline int pte_none(pte_t pte)
{
	return !(pte.pte & ~(_PAGE_KNL_ERRATUM_MASK));
}

#define __HAVE_ARCH_PTE_SAME
static inline int pte_same(pte_t a, pte_t b)
{
	return a.pte == b.pte;
}

static inline pte_t pte_advance_pfn(pte_t pte, unsigned long nr)
{
	if (__pte_needs_invert(pte_val(pte)))
		return __pte(pte_val(pte) - (nr << PFN_PTE_SHIFT));
	return __pte(pte_val(pte) + (nr << PFN_PTE_SHIFT));
}
#define pte_advance_pfn	pte_advance_pfn

static inline int pte_present(pte_t a)
{
	return pte_flags(a) & (_PAGE_PRESENT | _PAGE_PROTNONE);
}

#define pte_accessible pte_accessible
static inline bool pte_accessible(struct mm_struct *mm, pte_t a)
{
	if (pte_flags(a) & _PAGE_PRESENT)
		return true;

	if ((pte_flags(a) & _PAGE_PROTNONE) &&
			atomic_read(&mm->tlb_flush_pending))
		return true;

	return false;
}

static inline int pmd_present(pmd_t pmd)
{
	/*
	 * Checking for _PAGE_PSE is needed too because
	 * split_huge_page will temporarily clear the present bit (but
	 * the _PAGE_PSE flag will remain set at all times while the
	 * _PAGE_PRESENT bit is clear).
	 */
	return pmd_flags(pmd) & (_PAGE_PRESENT | _PAGE_PROTNONE | _PAGE_PSE);
}

#ifdef CONFIG_ARCH_HAS_PTE_PROTNONE
static inline int pte_protnone(pte_t pte)
{
	return (pte_flags(pte) & (_PAGE_PROTNONE | _PAGE_PRESENT))
		== _PAGE_PROTNONE;
}

static inline int pmd_protnone(pmd_t pmd)
{
	return (pmd_flags(pmd) & (_PAGE_PROTNONE | _PAGE_PRESENT))
		== _PAGE_PROTNONE;
}
#endif /* CONFIG_ARCH_HAS_PTE_PROTNONE */

static inline int pmd_none(pmd_t pmd)
{
	/* Only check low word on 32-bit platforms, since it might be
	   out of sync with upper half. */
	unsigned long val = native_pmd_val(pmd);
	return (val & ~_PAGE_KNL_ERRATUM_MASK) == 0;
}

static inline unsigned long pmd_page_vaddr(pmd_t pmd)
{
	return (unsigned long)__va(pmd_val(pmd) & pmd_pfn_mask(pmd));
}

/*
 * Currently stuck as a macro due to indirect forward reference to
 * linux/mmzone.h's __section_mem_map_addr() definition:
 */
#define pmd_page(pmd)	pfn_to_page(pmd_pfn(pmd))

static inline int pmd_bad(pmd_t pmd)
{
	return (pmd_flags(pmd) & ~(_PAGE_USER | _PAGE_ACCESSED)) !=
	       (_KERNPG_TABLE & ~_PAGE_ACCESSED);
}

static inline unsigned long pages_to_mb(unsigned long npg)
{
	return npg >> (20 - PAGE_SHIFT);
}

#if CONFIG_PGTABLE_LEVELS > 2
static inline int pud_none(pud_t pud)
{
	return (native_pud_val(pud) & ~(_PAGE_KNL_ERRATUM_MASK)) == 0;
}

static inline int pud_present(pud_t pud)
{
	return pud_flags(pud) & _PAGE_PRESENT;
}

static inline pmd_t *pud_pgtable(pud_t pud)
{
	return (pmd_t *)__va(pud_val(pud) & pud_pfn_mask(pud));
}

/*
 * Currently stuck as a macro due to indirect forward reference to
 * linux/mmzone.h's __section_mem_map_addr() definition:
 */
#define pud_page(pud)	pfn_to_page(pud_pfn(pud))

#define pud_leaf pud_leaf
static inline bool pud_leaf(pud_t pud)
{
	return pud_val(pud) & _PAGE_PSE;
}

static inline int pud_bad(pud_t pud)
{
	return (pud_flags(pud) & ~(_KERNPG_TABLE | _PAGE_USER)) != 0;
}
#endif	/* CONFIG_PGTABLE_LEVELS > 2 */

#if CONFIG_PGTABLE_LEVELS > 3
static inline int p4d_none(p4d_t p4d)
{
	return (native_p4d_val(p4d) & ~(_PAGE_KNL_ERRATUM_MASK)) == 0;
}

static inline int p4d_present(p4d_t p4d)
{
	return p4d_flags(p4d) & _PAGE_PRESENT;
}

static inline pud_t *p4d_pgtable(p4d_t p4d)
{
	return (pud_t *)__va(p4d_val(p4d) & p4d_pfn_mask(p4d));
}

/*
 * Currently stuck as a macro due to indirect forward reference to
 * linux/mmzone.h's __section_mem_map_addr() definition:
 */
#define p4d_page(p4d)	pfn_to_page(p4d_pfn(p4d))

static inline int p4d_bad(p4d_t p4d)
{
	unsigned long ignore_flags = _KERNPG_TABLE | _PAGE_USER;

	if (IS_ENABLED(CONFIG_MITIGATION_PAGE_TABLE_ISOLATION))
		ignore_flags |= _PAGE_NX;

	return (p4d_flags(p4d) & ~ignore_flags) != 0;
}
#endif  /* CONFIG_PGTABLE_LEVELS > 3 */

static inline unsigned long p4d_index(unsigned long address)
{
	return (address >> P4D_SHIFT) & (PTRS_PER_P4D - 1);
}

#if CONFIG_PGTABLE_LEVELS > 4
static inline int pgd_present(pgd_t pgd)
{
	if (!pgtable_l5_enabled())
		return 1;
	return pgd_flags(pgd) & _PAGE_PRESENT;
}

static inline unsigned long pgd_page_vaddr(pgd_t pgd)
{
	return (unsigned long)__va((unsigned long)pgd_val(pgd) & PTE_PFN_MASK);
}

/*
 * Currently stuck as a macro due to indirect forward reference to
 * linux/mmzone.h's __section_mem_map_addr() definition:
 */
#define pgd_page(pgd)	pfn_to_page(pgd_pfn(pgd))

/* to find an entry in a page-table-directory. */
static inline p4d_t *p4d_offset(pgd_t *pgd, unsigned long address)
{
	if (!pgtable_l5_enabled())
		return (p4d_t *)pgd;
	return (p4d_t *)pgd_page_vaddr(*pgd) + p4d_index(address);
}

static inline int pgd_bad(pgd_t pgd)
{
	unsigned long ignore_flags = _PAGE_USER;

	if (!pgtable_l5_enabled())
		return 0;

	if (IS_ENABLED(CONFIG_MITIGATION_PAGE_TABLE_ISOLATION))
		ignore_flags |= _PAGE_NX;

	return (pgd_flags(pgd) & ~ignore_flags) != _KERNPG_TABLE;
}

static inline int pgd_none(pgd_t pgd)
{
	if (!pgtable_l5_enabled())
		return 0;
	/*
	 * There is no need to do a workaround for the KNL stray
	 * A/D bit erratum here.  PGDs only point to page tables
	 * except on 32-bit non-PAE which is not supported on
	 * KNL.
	 */
	return !native_pgd_val(pgd);
}
#endif	/* CONFIG_PGTABLE_LEVELS > 4 */

#endif	/* __ASSEMBLER__ */

#define KERNEL_PGD_BOUNDARY	pgd_index(PAGE_OFFSET)
#define KERNEL_PGD_PTRS		(PTRS_PER_PGD - KERNEL_PGD_BOUNDARY)

#ifndef __ASSEMBLER__

extern int direct_gbpages;
void init_mem_mapping(void);
void early_alloc_pgt_buf(void);
void __init poking_init(void);
unsigned long init_memory_mapping(unsigned long start,
				  unsigned long end, pgprot_t prot);

#ifdef CONFIG_X86_64
extern pgd_t trampoline_pgd_entry;
#endif

/* local pte updates need not use xchg for locking */
static inline pte_t native_local_ptep_get_and_clear(pte_t *ptep)
{
	pte_t res = *ptep;

	/* Pure native function needs no input for mm, addr */
	native_pte_clear(NULL, 0, ptep);
	return res;
}

static inline pmd_t native_local_pmdp_get_and_clear(pmd_t *pmdp)
{
	pmd_t res = *pmdp;

	native_pmd_clear(pmdp);
	return res;
}

static inline pud_t native_local_pudp_get_and_clear(pud_t *pudp)
{
	pud_t res = *pudp;

	native_pud_clear(pudp);
	return res;
}

static inline void set_pmd_at(struct mm_struct *mm, unsigned long addr,
			      pmd_t *pmdp, pmd_t pmd)
{
	page_table_check_pmd_set(mm, addr, pmdp, pmd);
	set_pmd(pmdp, pmd);
}

static inline void set_pud_at(struct mm_struct *mm, unsigned long addr,
			      pud_t *pudp, pud_t pud)
{
	page_table_check_pud_set(mm, addr, pudp, pud);
	native_set_pud(pudp, pud);
}

/*
 * We only update the dirty/accessed state if we set
 * the dirty bit by hand in the kernel, since the hardware
 * will do the accessed bit for us, and we don't want to
 * race with other CPU's that might be updating the dirty
 * bit at the same time.
 */
struct vm_area_struct;

#define  __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);

#define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
bool ptep_test_and_clear_young(struct vm_area_struct *vma,
		unsigned long addr, pte_t *ptep);

#define __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
bool ptep_clear_flush_young(struct vm_area_struct *vma,
		unsigned long address, pte_t *ptep);

#define __HAVE_ARCH_PTEP_GET_AND_CLEAR
static inline pte_t ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
				       pte_t *ptep)
{
	pte_t pte = native_ptep_get_and_clear(ptep);
	page_table_check_pte_clear(mm, addr, pte);
	return pte;
}

#define __HAVE_ARCH_PTEP_GET_AND_CLEAR_FULL
static inline pte_t ptep_get_and_clear_full(struct mm_struct *mm,
					    unsigned long addr, pte_t *ptep,
					    int full)
{
	pte_t pte;
	if (full) {
		/*
		 * Full address destruction in progress; paravirt does not
		 * care about updates and native needs no locking
		 */
		pte = native_local_ptep_get_and_clear(ptep);
		page_table_check_pte_clear(mm, addr, pte);
	} else {
		pte = ptep_get_and_clear(mm, addr, ptep);
	}
	return pte;
}

#define __HAVE_ARCH_PTEP_SET_WRPROTECT
static inline void ptep_set_wrprotect(struct mm_struct *mm,
				      unsigned long addr, pte_t *ptep)
{
	/*
	 * Avoid accidentally creating shadow stack PTEs
	 * (Write=0,Dirty=1).  Use cmpxchg() to prevent races with
	 * the hardware setting Dirty=1.
	 */
	pte_t old_pte, new_pte;

	old_pte = READ_ONCE(*ptep);
	do {
		new_pte = pte_wrprotect(old_pte);
	} while (!try_cmpxchg((long *)&ptep->pte, (long *)&old_pte, *(long *)&new_pte));
}

/*
 * Note: strictly-zero compare is narrower than pte_none(), but the gap is
 * harmless: _PAGE_DIRTY and _PAGE_ACCESSED aren't set on untouched kernel PTEs.
 */
static inline bool ptep_try_set(pte_t *ptep, pte_t new_pte)
{
	pte_t old_pte = __pte(0);

	return try_cmpxchg((long *)&ptep->pte, (long *)&old_pte, *(long *)&new_pte);
}
#define ptep_try_set ptep_try_set

#define flush_tlb_fix_spurious_fault(vma, address, ptep) do { } while (0)

#define  __HAVE_ARCH_PMDP_SET_ACCESS_FLAGS
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);

#define __HAVE_ARCH_PMDP_TEST_AND_CLEAR_YOUNG
bool pmdp_test_and_clear_young(struct vm_area_struct *vma,
		unsigned long addr, pmd_t *pmdp);
bool pudp_test_and_clear_young(struct vm_area_struct *vma,
		unsigned long addr, pud_t *pudp);

#define __HAVE_ARCH_PMDP_CLEAR_YOUNG_FLUSH
bool pmdp_clear_flush_young(struct vm_area_struct *vma,
		unsigned long address, pmd_t *pmdp);


#define __HAVE_ARCH_PMDP_HUGE_GET_AND_CLEAR
static inline pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm, unsigned long addr,
				       pmd_t *pmdp)
{
	pmd_t pmd = native_pmdp_get_and_clear(pmdp);

	page_table_check_pmd_clear(mm, addr, pmd);

	return pmd;
}

#define __HAVE_ARCH_PUDP_HUGE_GET_AND_CLEAR
static inline pud_t pudp_huge_get_and_clear(struct mm_struct *mm,
					unsigned long addr, pud_t *pudp)
{
	pud_t pud = native_pudp_get_and_clear(pudp);

	page_table_check_pud_clear(mm, addr, pud);

	return pud;
}

#define __HAVE_ARCH_PMDP_SET_WRPROTECT
static inline void pmdp_set_wrprotect(struct mm_struct *mm,
				      unsigned long addr, pmd_t *pmdp)
{
	/*
	 * Avoid accidentally creating shadow stack PTEs
	 * (Write=0,Dirty=1).  Use cmpxchg() to prevent races with
	 * the hardware setting Dirty=1.
	 */
	pmd_t old_pmd, new_pmd;

	old_pmd = READ_ONCE(*pmdp);
	do {
		new_pmd = pmd_wrprotect(old_pmd);
	} while (!try_cmpxchg((long *)pmdp, (long *)&old_pmd, *(long *)&new_pmd));
}

#ifndef pmdp_establish
#define pmdp_establish pmdp_establish
static inline pmd_t pmdp_establish(struct vm_area_struct *vma,
		unsigned long address, pmd_t *pmdp, pmd_t pmd)
{
	page_table_check_pmd_set(vma->vm_mm, address, pmdp, pmd);
	if (IS_ENABLED(CONFIG_SMP)) {
		return xchg(pmdp, pmd);
	} else {
		pmd_t old = *pmdp;
		WRITE_ONCE(*pmdp, pmd);
		return old;
	}
}
#endif

#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
static inline pud_t pudp_establish(struct vm_area_struct *vma,
		unsigned long address, pud_t *pudp, pud_t pud)
{
	page_table_check_pud_set(vma->vm_mm, address, pudp, pud);
	if (IS_ENABLED(CONFIG_SMP)) {
		return xchg(pudp, pud);
	} else {
		pud_t old = *pudp;
		WRITE_ONCE(*pudp, pud);
		return old;
	}
}
#endif

#define __HAVE_ARCH_PMDP_INVALIDATE_AD
extern pmd_t pmdp_invalidate_ad(struct vm_area_struct *vma,
				unsigned long address, pmd_t *pmdp);

pud_t pudp_invalidate(struct vm_area_struct *vma, unsigned long address,
		      pud_t *pudp);

/*
 * Page table pages are page-aligned.  The lower half of the top
 * level is used for userspace and the top half for the kernel.
 *
 * Returns true for parts of the PGD that map userspace and
 * false for the parts that map the kernel.
 */
static inline bool pgdp_maps_userspace(void *__ptr)
{
	unsigned long ptr = (unsigned long)__ptr;

	return (((ptr & ~PAGE_MASK) / sizeof(pgd_t)) < PGD_KERNEL_START);
}

#ifdef CONFIG_MITIGATION_PAGE_TABLE_ISOLATION
/*
 * All top-level MITIGATION_PAGE_TABLE_ISOLATION page tables are order-1 pages
 * (8k-aligned and 8k in size).  The kernel one is at the beginning 4k and
 * the user one is in the last 4k.  To switch between them, you
 * just need to flip the 12th bit in their addresses.
 */
#define PTI_PGTABLE_SWITCH_BIT	PAGE_SHIFT

/*
 * This generates better code than the inline assembly in
 * __set_bit().
 */
static inline void *ptr_set_bit(void *ptr, int bit)
{
	unsigned long __ptr = (unsigned long)ptr;

	__ptr |= BIT(bit);
	return (void *)__ptr;
}
static inline void *ptr_clear_bit(void *ptr, int bit)
{
	unsigned long __ptr = (unsigned long)ptr;

	__ptr &= ~BIT(bit);
	return (void *)__ptr;
}

static inline pgd_t *kernel_to_user_pgdp(pgd_t *pgdp)
{
	return ptr_set_bit(pgdp, PTI_PGTABLE_SWITCH_BIT);
}

static inline pgd_t *user_to_kernel_pgdp(pgd_t *pgdp)
{
	return ptr_clear_bit(pgdp, PTI_PGTABLE_SWITCH_BIT);
}

static inline p4d_t *kernel_to_user_p4dp(p4d_t *p4dp)
{
	return ptr_set_bit(p4dp, PTI_PGTABLE_SWITCH_BIT);
}

static inline p4d_t *user_to_kernel_p4dp(p4d_t *p4dp)
{
	return ptr_clear_bit(p4dp, PTI_PGTABLE_SWITCH_BIT);
}
#endif /* CONFIG_MITIGATION_PAGE_TABLE_ISOLATION */

/*
 * clone_pgd_range(pgd_t *dst, pgd_t *src, int count);
 *
 *  dst - pointer to pgd range anywhere on a pgd page
 *  src - ""
 *  count - the number of pgds to copy.
 *
 * dst and src can be on the same page, but the range must not overlap,
 * and must not cross a page boundary.
 */
static inline void clone_pgd_range(pgd_t *dst, pgd_t *src, int count)
{
	memcpy(dst, src, count * sizeof(pgd_t));
#ifdef CONFIG_MITIGATION_PAGE_TABLE_ISOLATION
	if (!cpu_feature_enabled(X86_FEATURE_PTI))
		return;
	/* Clone the user space pgd as well */
	memcpy(kernel_to_user_pgdp(dst), kernel_to_user_pgdp(src),
	       count * sizeof(pgd_t));
#endif
}

#define PTE_SHIFT ilog2(PTRS_PER_PTE)
static inline int page_level_shift(enum pg_level level)
{
	return (PAGE_SHIFT - PTE_SHIFT) + level * PTE_SHIFT;
}
static inline unsigned long page_level_size(enum pg_level level)
{
	return 1UL << page_level_shift(level);
}
static inline unsigned long page_level_mask(enum pg_level level)
{
	return ~(page_level_size(level) - 1);
}

/*
 * The x86 doesn't have any external MMU info: the kernel page
 * tables contain all the necessary information.
 */
static inline void update_mmu_cache(struct vm_area_struct *vma,
		unsigned long addr, pte_t *ptep)
{
}
static inline void update_mmu_cache_range(struct vm_fault *vmf,
		struct vm_area_struct *vma, unsigned long addr,
		pte_t *ptep, unsigned int nr)
{
}
static inline void update_mmu_cache_pmd(struct vm_area_struct *vma,
		unsigned long addr, pmd_t *pmd)
{
}
static inline void update_mmu_cache_pud(struct vm_area_struct *vma,
		unsigned long addr, pud_t *pud)
{
}
static inline pte_t pte_swp_mkexclusive(pte_t pte)
{
	return pte_set_flags(pte, _PAGE_SWP_EXCLUSIVE);
}

static inline bool pte_swp_exclusive(pte_t pte)
{
	return pte_flags(pte) & _PAGE_SWP_EXCLUSIVE;
}

static inline pte_t pte_swp_clear_exclusive(pte_t pte)
{
	return pte_clear_flags(pte, _PAGE_SWP_EXCLUSIVE);
}

#ifdef CONFIG_HAVE_ARCH_SOFT_DIRTY
static inline pte_t pte_swp_mksoft_dirty(pte_t pte)
{
	return pte_set_flags(pte, _PAGE_SWP_SOFT_DIRTY);
}

static inline int pte_swp_soft_dirty(pte_t pte)
{
	return pte_flags(pte) & _PAGE_SWP_SOFT_DIRTY;
}

static inline pte_t pte_swp_clear_soft_dirty(pte_t pte)
{
	return pte_clear_flags(pte, _PAGE_SWP_SOFT_DIRTY);
}

#ifdef CONFIG_ARCH_HAS_PMD_SOFTLEAVES
static inline pmd_t pmd_swp_mksoft_dirty(pmd_t pmd)
{
	return pmd_set_flags(pmd, _PAGE_SWP_SOFT_DIRTY);
}

static inline int pmd_swp_soft_dirty(pmd_t pmd)
{
	return pmd_flags(pmd) & _PAGE_SWP_SOFT_DIRTY;
}

static inline pmd_t pmd_swp_clear_soft_dirty(pmd_t pmd)
{
	return pmd_clear_flags(pmd, _PAGE_SWP_SOFT_DIRTY);
}
#endif
#endif

#ifdef CONFIG_HAVE_ARCH_USERFAULTFD_WP
static inline pte_t pte_swp_mkuffd(pte_t pte)
{
	return pte_set_flags(pte, _PAGE_SWP_UFFD);
}

static inline int pte_swp_uffd(pte_t pte)
{
	return pte_flags(pte) & _PAGE_SWP_UFFD;
}

static inline pte_t pte_swp_clear_uffd(pte_t pte)
{
	return pte_clear_flags(pte, _PAGE_SWP_UFFD);
}

static inline pmd_t pmd_swp_mkuffd(pmd_t pmd)
{
	return pmd_set_flags(pmd, _PAGE_SWP_UFFD);
}

static inline int pmd_swp_uffd(pmd_t pmd)
{
	return pmd_flags(pmd) & _PAGE_SWP_UFFD;
}

static inline pmd_t pmd_swp_clear_uffd(pmd_t pmd)
{
	return pmd_clear_flags(pmd, _PAGE_SWP_UFFD);
}
#endif /* CONFIG_HAVE_ARCH_USERFAULTFD_WP */

static inline u16 pte_flags_pkey(unsigned long pte_flags)
{
#ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS
	/* ifdef to avoid doing 59-bit shift on 32-bit values */
	return (pte_flags & _PAGE_PKEY_MASK) >> _PAGE_BIT_PKEY_BIT0;
#else
	return 0;
#endif
}

static inline bool __pkru_allows_pkey(u16 pkey, bool write)
{
	u32 pkru = read_pkru();

	if (!__pkru_allows_read(pkru, pkey))
		return false;
	if (write && !__pkru_allows_write(pkru, pkey))
		return false;

	return true;
}

/*
 * 'pteval' can come from a PTE, PMD or PUD.  We only check
 * _PAGE_PRESENT, _PAGE_USER, and _PAGE_RW in here which are the
 * same value on all 3 types.
 */
static inline bool __pte_access_permitted(unsigned long pteval, bool write)
{
	unsigned long need_pte_bits = _PAGE_PRESENT|_PAGE_USER;

	/*
	 * Write=0,Dirty=1 PTEs are shadow stack, which the kernel
	 * shouldn't generally allow access to, but since they
	 * are already Write=0, the below logic covers both cases.
	 */
	if (write)
		need_pte_bits |= _PAGE_RW;

	if ((pteval & need_pte_bits) != need_pte_bits)
		return 0;

	return __pkru_allows_pkey(pte_flags_pkey(pteval), write);
}

#define pte_access_permitted pte_access_permitted
static inline bool pte_access_permitted(pte_t pte, bool write)
{
	return __pte_access_permitted(pte_val(pte), write);
}

#define pmd_access_permitted pmd_access_permitted
static inline bool pmd_access_permitted(pmd_t pmd, bool write)
{
	return __pte_access_permitted(pmd_val(pmd), write);
}

#define pud_access_permitted pud_access_permitted
static inline bool pud_access_permitted(pud_t pud, bool write)
{
	return __pte_access_permitted(pud_val(pud), write);
}

#define __HAVE_ARCH_PFN_MODIFY_ALLOWED 1
extern bool pfn_modify_allowed(unsigned long pfn, pgprot_t prot);

static inline bool arch_has_pfn_modify_check(void)
{
	return boot_cpu_has_bug(X86_BUG_L1TF);
}

#define arch_check_zapped_pte arch_check_zapped_pte
void arch_check_zapped_pte(struct vm_area_struct *vma, pte_t pte);

#define arch_check_zapped_pmd arch_check_zapped_pmd
void arch_check_zapped_pmd(struct vm_area_struct *vma, pmd_t pmd);

#define arch_check_zapped_pud arch_check_zapped_pud
void arch_check_zapped_pud(struct vm_area_struct *vma, pud_t pud);

#ifdef CONFIG_XEN_PV
#define arch_has_hw_nonleaf_pmd_young arch_has_hw_nonleaf_pmd_young
static inline bool arch_has_hw_nonleaf_pmd_young(void)
{
	return !cpu_feature_enabled(X86_FEATURE_XENPV);
}
#endif

#ifdef CONFIG_PAGE_TABLE_CHECK
static inline bool pte_user_accessible_page(struct mm_struct *mm, unsigned long addr, pte_t pte)
{
	return (pte_val(pte) & _PAGE_PRESENT) && (pte_val(pte) & _PAGE_USER);
}

static inline bool pmd_user_accessible_page(struct mm_struct *mm, unsigned long addr, pmd_t pmd)
{
	return pmd_leaf(pmd) && (pmd_val(pmd) & _PAGE_PRESENT) && (pmd_val(pmd) & _PAGE_USER);
}

static inline bool pud_user_accessible_page(struct mm_struct *mm, unsigned long addr, pud_t pud)
{
	return pud_leaf(pud) && (pud_val(pud) & _PAGE_PRESENT) && (pud_val(pud) & _PAGE_USER);
}
#endif

#ifdef CONFIG_X86_SGX
int arch_memory_failure(unsigned long pfn, int flags);
#define arch_memory_failure arch_memory_failure

bool arch_is_platform_page(u64 paddr);
#define arch_is_platform_page arch_is_platform_page
#endif

/*
 * Use set_p*_safe(), and elide TLB flushing, when confident that *no*
 * TLB flush will be required as a result of the "set". For example, use
 * in scenarios where it is known ahead of time that the routine is
 * setting non-present entries, or re-setting an existing entry to the
 * same value. Otherwise, use the typical "set" helpers and flush the
 * TLB.
 */
#define set_pte_safe(ptep, pte) \
({ \
	WARN_ON_ONCE(pte_present(*ptep) && !pte_same(*ptep, pte)); \
	set_pte(ptep, pte); \
})

#define set_pmd_safe(pmdp, pmd) \
({ \
	WARN_ON_ONCE(pmd_present(*pmdp) && !pmd_same(*pmdp, pmd)); \
	set_pmd(pmdp, pmd); \
})

#define set_pud_safe(pudp, pud) \
({ \
	WARN_ON_ONCE(pud_present(*pudp) && !pud_same(*pudp, pud)); \
	set_pud(pudp, pud); \
})

#define set_p4d_safe(p4dp, p4d) \
({ \
	WARN_ON_ONCE(p4d_present(*p4dp) && !p4d_same(*p4dp, p4d)); \
	set_p4d(p4dp, p4d); \
})

#define set_pgd_safe(pgdp, pgd) \
({ \
	WARN_ON_ONCE(pgd_present(*pgdp) && !pgd_same(*pgdp, pgd)); \
	set_pgd(pgdp, pgd); \
})
#endif	/* __ASSEMBLER__ */

#endif /* _ASM_X86_PGTABLE_H */