include/linux/huge_mm.h

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