linux/include/linux/huge_mm.h

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

#include <linux/sched/coredump.h>
#include <linux/mm_types.h>

#include <linux/fs.h> /* only for vma_is_dax() */
#include <linux/kobject.h>

vm_fault_t do_huge_pmd_anonymous_page(struct vm_fault *vmf);
int copy_huge_pmd(struct mm_struct *dst_mm, struct mm_struct *src_mm,
		  pmd_t *dst_pmd, pmd_t *src_pmd, unsigned long addr,
		  struct vm_area_struct *dst_vma, struct vm_area_struct *src_vma);
void huge_pmd_set_accessed(struct vm_fault *vmf);
int copy_huge_pud(struct mm_struct *dst_mm, struct mm_struct *src_mm,
		  pud_t *dst_pud, pud_t *src_pud, unsigned long addr,
		  struct vm_area_struct *vma);

#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
void huge_pud_set_accessed(struct vm_fault *vmf, pud_t orig_pud);
#else
static inline void huge_pud_set_accessed(struct vm_fault *vmf, pud_t orig_pud)
{
}
#endif

vm_fault_t do_huge_pmd_wp_page(struct vm_fault *vmf);
bool madvise_free_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma,
			   pmd_t *pmd, unsigned long addr, unsigned long next);
int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma, pmd_t *pmd,
		 unsigned long addr);
int zap_huge_pud(struct mmu_gather *tlb, struct vm_area_struct *vma, pud_t *pud,
		 unsigned long addr);
bool move_huge_pmd(struct vm_area_struct *vma, unsigned long old_addr,
		   unsigned long new_addr, pmd_t *old_pmd, pmd_t *new_pmd);
int change_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma,
		    pmd_t *pmd, unsigned long addr, pgprot_t newprot,
		    unsigned long cp_flags);

vm_fault_t vmf_insert_pfn_pmd(struct vm_fault *vmf, pfn_t pfn, bool write);
vm_fault_t vmf_insert_pfn_pud(struct vm_fault *vmf, pfn_t pfn, bool write);

enum transparent_hugepage_flag {};

struct kobject;
struct kobj_attribute;

ssize_t single_hugepage_flag_store(struct kobject *kobj,
				   struct kobj_attribute *attr,
				   const char *buf, size_t count,
				   enum transparent_hugepage_flag flag);
ssize_t single_hugepage_flag_show(struct kobject *kobj,
				  struct kobj_attribute *attr, char *buf,
				  enum transparent_hugepage_flag flag);
extern struct kobj_attribute shmem_enabled_attr;
extern struct kobj_attribute thpsize_shmem_enabled_attr;

/*
 * Mask of all large folio orders supported for anonymous THP; all orders up to
 * and including PMD_ORDER, except order-0 (which is not "huge") and order-1
 * (which is a limitation of the THP implementation).
 */
#define THP_ORDERS_ALL_ANON

/*
 * Mask of all large folio orders supported for file THP. Folios in a DAX
 * file is never split and the MAX_PAGECACHE_ORDER limit does not apply to
 * it.  Same to PFNMAPs where there's neither page* nor pagecache.
 */
#define THP_ORDERS_ALL_SPECIAL
#define THP_ORDERS_ALL_FILE_DEFAULT

/*
 * Mask of all large folio orders supported for THP.
 */
#define THP_ORDERS_ALL

#define TVA_SMAPS
#define TVA_IN_PF
#define TVA_ENFORCE_SYSFS

#define thp_vma_allowable_order(vma, vm_flags, tva_flags, order)

#define split_folio(f)

#ifdef CONFIG_PGTABLE_HAS_HUGE_LEAVES
#define HPAGE_PMD_SHIFT
#define HPAGE_PUD_SHIFT
#else
#define HPAGE_PMD_SHIFT
#define HPAGE_PUD_SHIFT
#endif

#define HPAGE_PMD_ORDER
#define HPAGE_PMD_NR
#define HPAGE_PMD_MASK
#define HPAGE_PMD_SIZE

#define HPAGE_PUD_ORDER
#define HPAGE_PUD_NR
#define HPAGE_PUD_MASK
#define HPAGE_PUD_SIZE

enum mthp_stat_item {};

#if defined(CONFIG_TRANSPARENT_HUGEPAGE) && defined(CONFIG_SYSFS)
struct mthp_stat {};

DECLARE_PER_CPU(struct mthp_stat, mthp_stats);

static inline void mod_mthp_stat(int order, enum mthp_stat_item item, int delta)
{}

static inline void count_mthp_stat(int order, enum mthp_stat_item item)
{}

#else
static inline void mod_mthp_stat(int order, enum mthp_stat_item item, int delta)
{
}

static inline void count_mthp_stat(int order, enum mthp_stat_item item)
{
}
#endif

#ifdef CONFIG_TRANSPARENT_HUGEPAGE

extern unsigned long transparent_hugepage_flags;
extern unsigned long huge_anon_orders_always;
extern unsigned long huge_anon_orders_madvise;
extern unsigned long huge_anon_orders_inherit;

static inline bool hugepage_global_enabled(void)
{}

static inline bool hugepage_global_always(void)
{}

static inline int highest_order(unsigned long orders)
{}

static inline int next_order(unsigned long *orders, int prev)
{}

/*
 * Do the below checks:
 *   - For file vma, check if the linear page offset of vma is
 *     order-aligned within the file.  The hugepage is
 *     guaranteed to be order-aligned within the file, but we must
 *     check that the order-aligned addresses in the VMA map to
 *     order-aligned offsets within the file, else the hugepage will
 *     not be mappable.
 *   - For all vmas, check if the haddr is in an aligned hugepage
 *     area.
 */
static inline bool thp_vma_suitable_order(struct vm_area_struct *vma,
		unsigned long addr, int order)
{}

/*
 * Filter the bitfield of input orders to the ones suitable for use in the vma.
 * See thp_vma_suitable_order().
 * All orders that pass the checks are returned as a bitfield.
 */
static inline unsigned long thp_vma_suitable_orders(struct vm_area_struct *vma,
		unsigned long addr, unsigned long orders)
{}

static inline bool file_thp_enabled(struct vm_area_struct *vma)
{}

unsigned long __thp_vma_allowable_orders(struct vm_area_struct *vma,
					 unsigned long vm_flags,
					 unsigned long tva_flags,
					 unsigned long orders);

/**
 * thp_vma_allowable_orders - determine hugepage orders that are allowed for vma
 * @vma:  the vm area to check
 * @vm_flags: use these vm_flags instead of vma->vm_flags
 * @tva_flags: Which TVA flags to honour
 * @orders: bitfield of all orders to consider
 *
 * Calculates the intersection of the requested hugepage orders and the allowed
 * hugepage orders for the provided vma. Permitted orders are encoded as a set
 * bit at the corresponding bit position (bit-2 corresponds to order-2, bit-3
 * corresponds to order-3, etc). Order-0 is never considered a hugepage order.
 *
 * Return: bitfield of orders allowed for hugepage in the vma. 0 if no hugepage
 * orders are allowed.
 */
static inline
unsigned long thp_vma_allowable_orders(struct vm_area_struct *vma,
				       unsigned long vm_flags,
				       unsigned long tva_flags,
				       unsigned long orders)
{}

struct thpsize {};

#define to_thpsize(kobj)

#define transparent_hugepage_use_zero_page()

unsigned long thp_get_unmapped_area(struct file *filp, unsigned long addr,
		unsigned long len, unsigned long pgoff, unsigned long flags);
unsigned long thp_get_unmapped_area_vmflags(struct file *filp, unsigned long addr,
		unsigned long len, unsigned long pgoff, unsigned long flags,
		vm_flags_t vm_flags);

bool can_split_folio(struct folio *folio, int caller_pins, int *pextra_pins);
int split_huge_page_to_list_to_order(struct page *page, struct list_head *list,
		unsigned int new_order);
int min_order_for_split(struct folio *folio);
int split_folio_to_list(struct folio *folio, struct list_head *list);
static inline int split_huge_page(struct page *page)
{}
void deferred_split_folio(struct folio *folio, bool partially_mapped);

void __split_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
		unsigned long address, bool freeze, struct folio *folio);

#define split_huge_pmd(__vma, __pmd, __address)


void split_huge_pmd_address(struct vm_area_struct *vma, unsigned long address,
		bool freeze, struct folio *folio);

void __split_huge_pud(struct vm_area_struct *vma, pud_t *pud,
		unsigned long address);

#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
int change_huge_pud(struct mmu_gather *tlb, struct vm_area_struct *vma,
		    pud_t *pudp, unsigned long addr, pgprot_t newprot,
		    unsigned long cp_flags);
#else
static inline int
change_huge_pud(struct mmu_gather *tlb, struct vm_area_struct *vma,
		pud_t *pudp, unsigned long addr, pgprot_t newprot,
		unsigned long cp_flags) { return 0; }
#endif

#define split_huge_pud(__vma, __pud, __address)

int hugepage_madvise(struct vm_area_struct *vma, unsigned long *vm_flags,
		     int advice);
int madvise_collapse(struct vm_area_struct *vma,
		     struct vm_area_struct **prev,
		     unsigned long start, unsigned long end);
void vma_adjust_trans_huge(struct vm_area_struct *vma, unsigned long start,
			   unsigned long end, long adjust_next);
spinlock_t *__pmd_trans_huge_lock(pmd_t *pmd, struct vm_area_struct *vma);
spinlock_t *__pud_trans_huge_lock(pud_t *pud, struct vm_area_struct *vma);

static inline int is_swap_pmd(pmd_t pmd)
{}

/* mmap_lock must be held on entry */
static inline spinlock_t *pmd_trans_huge_lock(pmd_t *pmd,
		struct vm_area_struct *vma)
{}
static inline spinlock_t *pud_trans_huge_lock(pud_t *pud,
		struct vm_area_struct *vma)
{}

/**
 * folio_test_pmd_mappable - Can we map this folio with a PMD?
 * @folio: The folio to test
 */
static inline bool folio_test_pmd_mappable(struct folio *folio)
{}

struct page *follow_devmap_pmd(struct vm_area_struct *vma, unsigned long addr,
		pmd_t *pmd, int flags, struct dev_pagemap **pgmap);

vm_fault_t do_huge_pmd_numa_page(struct vm_fault *vmf);

extern struct folio *huge_zero_folio;
extern unsigned long huge_zero_pfn;

static inline bool is_huge_zero_folio(const struct folio *folio)
{}

static inline bool is_huge_zero_pmd(pmd_t pmd)
{}

struct folio *mm_get_huge_zero_folio(struct mm_struct *mm);
void mm_put_huge_zero_folio(struct mm_struct *mm);

#define mk_huge_pmd(page, prot)

static inline bool thp_migration_supported(void)
{}

void split_huge_pmd_locked(struct vm_area_struct *vma, unsigned long address,
			   pmd_t *pmd, bool freeze, struct folio *folio);
bool unmap_huge_pmd_locked(struct vm_area_struct *vma, unsigned long addr,
			   pmd_t *pmdp, struct folio *folio);

#else /* CONFIG_TRANSPARENT_HUGEPAGE */

static inline bool folio_test_pmd_mappable(struct folio *folio)
{
	return false;
}

static inline bool thp_vma_suitable_order(struct vm_area_struct *vma,
		unsigned long addr, int order)
{
	return false;
}

static inline unsigned long thp_vma_suitable_orders(struct vm_area_struct *vma,
		unsigned long addr, unsigned long orders)
{
	return 0;
}

static inline unsigned long thp_vma_allowable_orders(struct vm_area_struct *vma,
					unsigned long vm_flags,
					unsigned long tva_flags,
					unsigned long orders)
{
	return 0;
}

#define transparent_hugepage_flags

#define thp_get_unmapped_area

static inline unsigned long
thp_get_unmapped_area_vmflags(struct file *filp, unsigned long addr,
			      unsigned long len, unsigned long pgoff,
			      unsigned long flags, vm_flags_t vm_flags)
{
	return 0;
}

static inline bool
can_split_folio(struct folio *folio, int caller_pins, int *pextra_pins)
{
	return false;
}
static inline int
split_huge_page_to_list_to_order(struct page *page, struct list_head *list,
		unsigned int new_order)
{
	return 0;
}
static inline int split_huge_page(struct page *page)
{
	return 0;
}

static inline int split_folio_to_list(struct folio *folio, struct list_head *list)
{
	return 0;
}

static inline void deferred_split_folio(struct folio *folio, bool partially_mapped) {}
#define split_huge_pmd

static inline void __split_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
		unsigned long address, bool freeze, struct folio *folio) {}
static inline void split_huge_pmd_address(struct vm_area_struct *vma,
		unsigned long address, bool freeze, struct folio *folio) {}
static inline void split_huge_pmd_locked(struct vm_area_struct *vma,
					 unsigned long address, pmd_t *pmd,
					 bool freeze, struct folio *folio) {}

static inline bool unmap_huge_pmd_locked(struct vm_area_struct *vma,
					 unsigned long addr, pmd_t *pmdp,
					 struct folio *folio)
{
	return false;
}

#define split_huge_pud

static inline int hugepage_madvise(struct vm_area_struct *vma,
				   unsigned long *vm_flags, int advice)
{
	return -EINVAL;
}

static inline int madvise_collapse(struct vm_area_struct *vma,
				   struct vm_area_struct **prev,
				   unsigned long start, unsigned long end)
{
	return -EINVAL;
}

static inline void vma_adjust_trans_huge(struct vm_area_struct *vma,
					 unsigned long start,
					 unsigned long end,
					 long adjust_next)
{
}
static inline int is_swap_pmd(pmd_t pmd)
{
	return 0;
}
static inline spinlock_t *pmd_trans_huge_lock(pmd_t *pmd,
		struct vm_area_struct *vma)
{
	return NULL;
}
static inline spinlock_t *pud_trans_huge_lock(pud_t *pud,
		struct vm_area_struct *vma)
{
	return NULL;
}

static inline vm_fault_t do_huge_pmd_numa_page(struct vm_fault *vmf)
{
	return 0;
}

static inline bool is_huge_zero_folio(const struct folio *folio)
{
	return false;
}

static inline bool is_huge_zero_pmd(pmd_t pmd)
{
	return false;
}

static inline void mm_put_huge_zero_folio(struct mm_struct *mm)
{
	return;
}

static inline struct page *follow_devmap_pmd(struct vm_area_struct *vma,
	unsigned long addr, pmd_t *pmd, int flags, struct dev_pagemap **pgmap)
{
	return NULL;
}

static inline bool thp_migration_supported(void)
{
	return false;
}

static inline int highest_order(unsigned long orders)
{
	return 0;
}

static inline int next_order(unsigned long *orders, int prev)
{
	return 0;
}

static inline void __split_huge_pud(struct vm_area_struct *vma, pud_t *pud,
				    unsigned long address)
{
}

static inline int change_huge_pud(struct mmu_gather *tlb,
				  struct vm_area_struct *vma, pud_t *pudp,
				  unsigned long addr, pgprot_t newprot,
				  unsigned long cp_flags)
{
	return 0;
}
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */

static inline int split_folio_to_list_to_order(struct folio *folio,
		struct list_head *list, int new_order)
{}

static inline int split_folio_to_order(struct folio *folio, int new_order)
{}

#endif /* _LINUX_HUGE_MM_H */