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