linux/include/linux/huge_mm.h
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   1/* SPDX-License-Identifier: GPL-2.0 */
   2#ifndef _LINUX_HUGE_MM_H
   3#define _LINUX_HUGE_MM_H
   4
   5#include <linux/sched/coredump.h>
   6#include <linux/mm_types.h>
   7
   8#include <linux/fs.h> /* only for vma_is_dax() */
   9
  10extern vm_fault_t do_huge_pmd_anonymous_page(struct vm_fault *vmf);
  11extern int copy_huge_pmd(struct mm_struct *dst_mm, struct mm_struct *src_mm,
  12                         pmd_t *dst_pmd, pmd_t *src_pmd, unsigned long addr,
  13                         struct vm_area_struct *vma);
  14extern void huge_pmd_set_accessed(struct vm_fault *vmf, pmd_t orig_pmd);
  15extern int copy_huge_pud(struct mm_struct *dst_mm, struct mm_struct *src_mm,
  16                         pud_t *dst_pud, pud_t *src_pud, unsigned long addr,
  17                         struct vm_area_struct *vma);
  18
  19#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
  20extern void huge_pud_set_accessed(struct vm_fault *vmf, pud_t orig_pud);
  21#else
  22static inline void huge_pud_set_accessed(struct vm_fault *vmf, pud_t orig_pud)
  23{
  24}
  25#endif
  26
  27extern vm_fault_t do_huge_pmd_wp_page(struct vm_fault *vmf, pmd_t orig_pmd);
  28extern struct page *follow_trans_huge_pmd(struct vm_area_struct *vma,
  29                                          unsigned long addr,
  30                                          pmd_t *pmd,
  31                                          unsigned int flags);
  32extern bool madvise_free_huge_pmd(struct mmu_gather *tlb,
  33                        struct vm_area_struct *vma,
  34                        pmd_t *pmd, unsigned long addr, unsigned long next);
  35extern int zap_huge_pmd(struct mmu_gather *tlb,
  36                        struct vm_area_struct *vma,
  37                        pmd_t *pmd, unsigned long addr);
  38extern int zap_huge_pud(struct mmu_gather *tlb,
  39                        struct vm_area_struct *vma,
  40                        pud_t *pud, unsigned long addr);
  41extern int mincore_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
  42                        unsigned long addr, unsigned long end,
  43                        unsigned char *vec);
  44extern bool move_huge_pmd(struct vm_area_struct *vma, unsigned long old_addr,
  45                         unsigned long new_addr, unsigned long old_end,
  46                         pmd_t *old_pmd, pmd_t *new_pmd);
  47extern int change_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
  48                        unsigned long addr, pgprot_t newprot,
  49                        int prot_numa);
  50vm_fault_t vmf_insert_pfn_pmd(struct vm_fault *vmf, pfn_t pfn, bool write);
  51vm_fault_t vmf_insert_pfn_pud(struct vm_fault *vmf, pfn_t pfn, bool write);
  52enum transparent_hugepage_flag {
  53        TRANSPARENT_HUGEPAGE_FLAG,
  54        TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG,
  55        TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG,
  56        TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_FLAG,
  57        TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG,
  58        TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG,
  59        TRANSPARENT_HUGEPAGE_DEFRAG_KHUGEPAGED_FLAG,
  60        TRANSPARENT_HUGEPAGE_USE_ZERO_PAGE_FLAG,
  61#ifdef CONFIG_DEBUG_VM
  62        TRANSPARENT_HUGEPAGE_DEBUG_COW_FLAG,
  63#endif
  64};
  65
  66struct kobject;
  67struct kobj_attribute;
  68
  69extern ssize_t single_hugepage_flag_store(struct kobject *kobj,
  70                                 struct kobj_attribute *attr,
  71                                 const char *buf, size_t count,
  72                                 enum transparent_hugepage_flag flag);
  73extern ssize_t single_hugepage_flag_show(struct kobject *kobj,
  74                                struct kobj_attribute *attr, char *buf,
  75                                enum transparent_hugepage_flag flag);
  76extern struct kobj_attribute shmem_enabled_attr;
  77
  78#define HPAGE_PMD_ORDER (HPAGE_PMD_SHIFT-PAGE_SHIFT)
  79#define HPAGE_PMD_NR (1<<HPAGE_PMD_ORDER)
  80
  81#ifdef CONFIG_TRANSPARENT_HUGEPAGE
  82#define HPAGE_PMD_SHIFT PMD_SHIFT
  83#define HPAGE_PMD_SIZE  ((1UL) << HPAGE_PMD_SHIFT)
  84#define HPAGE_PMD_MASK  (~(HPAGE_PMD_SIZE - 1))
  85
  86#define HPAGE_PUD_SHIFT PUD_SHIFT
  87#define HPAGE_PUD_SIZE  ((1UL) << HPAGE_PUD_SHIFT)
  88#define HPAGE_PUD_MASK  (~(HPAGE_PUD_SIZE - 1))
  89
  90extern bool is_vma_temporary_stack(struct vm_area_struct *vma);
  91
  92extern unsigned long transparent_hugepage_flags;
  93
  94/*
  95 * to be used on vmas which are known to support THP.
  96 * Use transparent_hugepage_enabled otherwise
  97 */
  98static inline bool __transparent_hugepage_enabled(struct vm_area_struct *vma)
  99{
 100        if (vma->vm_flags & VM_NOHUGEPAGE)
 101                return false;
 102
 103        if (is_vma_temporary_stack(vma))
 104                return false;
 105
 106        if (test_bit(MMF_DISABLE_THP, &vma->vm_mm->flags))
 107                return false;
 108
 109        if (transparent_hugepage_flags & (1 << TRANSPARENT_HUGEPAGE_FLAG))
 110                return true;
 111
 112        if (vma_is_dax(vma))
 113                return true;
 114
 115        if (transparent_hugepage_flags &
 116                                (1 << TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG))
 117                return !!(vma->vm_flags & VM_HUGEPAGE);
 118
 119        return false;
 120}
 121
 122bool transparent_hugepage_enabled(struct vm_area_struct *vma);
 123
 124#define transparent_hugepage_use_zero_page()                            \
 125        (transparent_hugepage_flags &                                   \
 126         (1<<TRANSPARENT_HUGEPAGE_USE_ZERO_PAGE_FLAG))
 127#ifdef CONFIG_DEBUG_VM
 128#define transparent_hugepage_debug_cow()                                \
 129        (transparent_hugepage_flags &                                   \
 130         (1<<TRANSPARENT_HUGEPAGE_DEBUG_COW_FLAG))
 131#else /* CONFIG_DEBUG_VM */
 132#define transparent_hugepage_debug_cow() 0
 133#endif /* CONFIG_DEBUG_VM */
 134
 135extern unsigned long thp_get_unmapped_area(struct file *filp,
 136                unsigned long addr, unsigned long len, unsigned long pgoff,
 137                unsigned long flags);
 138
 139extern void prep_transhuge_page(struct page *page);
 140extern void free_transhuge_page(struct page *page);
 141
 142bool can_split_huge_page(struct page *page, int *pextra_pins);
 143int split_huge_page_to_list(struct page *page, struct list_head *list);
 144static inline int split_huge_page(struct page *page)
 145{
 146        return split_huge_page_to_list(page, NULL);
 147}
 148void deferred_split_huge_page(struct page *page);
 149
 150void __split_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
 151                unsigned long address, bool freeze, struct page *page);
 152
 153#define split_huge_pmd(__vma, __pmd, __address)                         \
 154        do {                                                            \
 155                pmd_t *____pmd = (__pmd);                               \
 156                if (is_swap_pmd(*____pmd) || pmd_trans_huge(*____pmd)   \
 157                                        || pmd_devmap(*____pmd))        \
 158                        __split_huge_pmd(__vma, __pmd, __address,       \
 159                                                false, NULL);           \
 160        }  while (0)
 161
 162
 163void split_huge_pmd_address(struct vm_area_struct *vma, unsigned long address,
 164                bool freeze, struct page *page);
 165
 166void __split_huge_pud(struct vm_area_struct *vma, pud_t *pud,
 167                unsigned long address);
 168
 169#define split_huge_pud(__vma, __pud, __address)                         \
 170        do {                                                            \
 171                pud_t *____pud = (__pud);                               \
 172                if (pud_trans_huge(*____pud)                            \
 173                                        || pud_devmap(*____pud))        \
 174                        __split_huge_pud(__vma, __pud, __address);      \
 175        }  while (0)
 176
 177extern int hugepage_madvise(struct vm_area_struct *vma,
 178                            unsigned long *vm_flags, int advice);
 179extern void vma_adjust_trans_huge(struct vm_area_struct *vma,
 180                                    unsigned long start,
 181                                    unsigned long end,
 182                                    long adjust_next);
 183extern spinlock_t *__pmd_trans_huge_lock(pmd_t *pmd,
 184                struct vm_area_struct *vma);
 185extern spinlock_t *__pud_trans_huge_lock(pud_t *pud,
 186                struct vm_area_struct *vma);
 187
 188static inline int is_swap_pmd(pmd_t pmd)
 189{
 190        return !pmd_none(pmd) && !pmd_present(pmd);
 191}
 192
 193/* mmap_sem must be held on entry */
 194static inline spinlock_t *pmd_trans_huge_lock(pmd_t *pmd,
 195                struct vm_area_struct *vma)
 196{
 197        VM_BUG_ON_VMA(!rwsem_is_locked(&vma->vm_mm->mmap_sem), vma);
 198        if (is_swap_pmd(*pmd) || pmd_trans_huge(*pmd) || pmd_devmap(*pmd))
 199                return __pmd_trans_huge_lock(pmd, vma);
 200        else
 201                return NULL;
 202}
 203static inline spinlock_t *pud_trans_huge_lock(pud_t *pud,
 204                struct vm_area_struct *vma)
 205{
 206        VM_BUG_ON_VMA(!rwsem_is_locked(&vma->vm_mm->mmap_sem), vma);
 207        if (pud_trans_huge(*pud) || pud_devmap(*pud))
 208                return __pud_trans_huge_lock(pud, vma);
 209        else
 210                return NULL;
 211}
 212static inline int hpage_nr_pages(struct page *page)
 213{
 214        if (unlikely(PageTransHuge(page)))
 215                return HPAGE_PMD_NR;
 216        return 1;
 217}
 218
 219struct page *follow_devmap_pmd(struct vm_area_struct *vma, unsigned long addr,
 220                pmd_t *pmd, int flags, struct dev_pagemap **pgmap);
 221struct page *follow_devmap_pud(struct vm_area_struct *vma, unsigned long addr,
 222                pud_t *pud, int flags, struct dev_pagemap **pgmap);
 223
 224extern vm_fault_t do_huge_pmd_numa_page(struct vm_fault *vmf, pmd_t orig_pmd);
 225
 226extern struct page *huge_zero_page;
 227
 228static inline bool is_huge_zero_page(struct page *page)
 229{
 230        return READ_ONCE(huge_zero_page) == page;
 231}
 232
 233static inline bool is_huge_zero_pmd(pmd_t pmd)
 234{
 235        return is_huge_zero_page(pmd_page(pmd));
 236}
 237
 238static inline bool is_huge_zero_pud(pud_t pud)
 239{
 240        return false;
 241}
 242
 243struct page *mm_get_huge_zero_page(struct mm_struct *mm);
 244void mm_put_huge_zero_page(struct mm_struct *mm);
 245
 246#define mk_huge_pmd(page, prot) pmd_mkhuge(mk_pmd(page, prot))
 247
 248static inline bool thp_migration_supported(void)
 249{
 250        return IS_ENABLED(CONFIG_ARCH_ENABLE_THP_MIGRATION);
 251}
 252
 253#else /* CONFIG_TRANSPARENT_HUGEPAGE */
 254#define HPAGE_PMD_SHIFT ({ BUILD_BUG(); 0; })
 255#define HPAGE_PMD_MASK ({ BUILD_BUG(); 0; })
 256#define HPAGE_PMD_SIZE ({ BUILD_BUG(); 0; })
 257
 258#define HPAGE_PUD_SHIFT ({ BUILD_BUG(); 0; })
 259#define HPAGE_PUD_MASK ({ BUILD_BUG(); 0; })
 260#define HPAGE_PUD_SIZE ({ BUILD_BUG(); 0; })
 261
 262#define hpage_nr_pages(x) 1
 263
 264static inline bool __transparent_hugepage_enabled(struct vm_area_struct *vma)
 265{
 266        return false;
 267}
 268
 269static inline bool transparent_hugepage_enabled(struct vm_area_struct *vma)
 270{
 271        return false;
 272}
 273
 274static inline void prep_transhuge_page(struct page *page) {}
 275
 276#define transparent_hugepage_flags 0UL
 277
 278#define thp_get_unmapped_area   NULL
 279
 280static inline bool
 281can_split_huge_page(struct page *page, int *pextra_pins)
 282{
 283        BUILD_BUG();
 284        return false;
 285}
 286static inline int
 287split_huge_page_to_list(struct page *page, struct list_head *list)
 288{
 289        return 0;
 290}
 291static inline int split_huge_page(struct page *page)
 292{
 293        return 0;
 294}
 295static inline void deferred_split_huge_page(struct page *page) {}
 296#define split_huge_pmd(__vma, __pmd, __address) \
 297        do { } while (0)
 298
 299static inline void __split_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
 300                unsigned long address, bool freeze, struct page *page) {}
 301static inline void split_huge_pmd_address(struct vm_area_struct *vma,
 302                unsigned long address, bool freeze, struct page *page) {}
 303
 304#define split_huge_pud(__vma, __pmd, __address) \
 305        do { } while (0)
 306
 307static inline int hugepage_madvise(struct vm_area_struct *vma,
 308                                   unsigned long *vm_flags, int advice)
 309{
 310        BUG();
 311        return 0;
 312}
 313static inline void vma_adjust_trans_huge(struct vm_area_struct *vma,
 314                                         unsigned long start,
 315                                         unsigned long end,
 316                                         long adjust_next)
 317{
 318}
 319static inline int is_swap_pmd(pmd_t pmd)
 320{
 321        return 0;
 322}
 323static inline spinlock_t *pmd_trans_huge_lock(pmd_t *pmd,
 324                struct vm_area_struct *vma)
 325{
 326        return NULL;
 327}
 328static inline spinlock_t *pud_trans_huge_lock(pud_t *pud,
 329                struct vm_area_struct *vma)
 330{
 331        return NULL;
 332}
 333
 334static inline vm_fault_t do_huge_pmd_numa_page(struct vm_fault *vmf,
 335                pmd_t orig_pmd)
 336{
 337        return 0;
 338}
 339
 340static inline bool is_huge_zero_page(struct page *page)
 341{
 342        return false;
 343}
 344
 345static inline bool is_huge_zero_pud(pud_t pud)
 346{
 347        return false;
 348}
 349
 350static inline void mm_put_huge_zero_page(struct mm_struct *mm)
 351{
 352        return;
 353}
 354
 355static inline struct page *follow_devmap_pmd(struct vm_area_struct *vma,
 356        unsigned long addr, pmd_t *pmd, int flags, struct dev_pagemap **pgmap)
 357{
 358        return NULL;
 359}
 360
 361static inline struct page *follow_devmap_pud(struct vm_area_struct *vma,
 362        unsigned long addr, pud_t *pud, int flags, struct dev_pagemap **pgmap)
 363{
 364        return NULL;
 365}
 366
 367static inline bool thp_migration_supported(void)
 368{
 369        return false;
 370}
 371#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 372
 373#endif /* _LINUX_HUGE_MM_H */
 374