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_fault *vmf, pfn_t pfn, bool write);
  51 vm_fault_t vmf_insert_pfn_pud(struct vm_fault *vmf, pfn_t pfn, bool write);
  52 enum 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
  66 struct kobject;
  67 struct kobj_attribute;
  68
  69 extern 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);
  73 extern ssize_t single_hugepage_flag_show(struct kobject *kobj,
  74                                 struct kobj_attribute *attr, char *buf,
  75                                 enum transparent_hugepage_flag flag);
  76 extern 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
  90 extern bool is_vma_temporary_stack(struct vm_area_struct *vma);
  91
  92 extern 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  */
  98 static 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
 122 bool 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
 135 extern unsigned long thp_get_unmapped_area(struct file *filp,
 136                 unsigned long addr, unsigned long len, unsigned long pgoff,
 137                 unsigned long flags);
 138
 139 extern void prep_transhuge_page(struct page *page);
 140 extern void free_transhuge_page(struct page *page);
 141
 142 bool can_split_huge_page(struct page *page, int *pextra_pins);
 143 int split_huge_page_to_list(struct page *page, struct list_head *list);
 144 static inline int split_huge_page(struct page *page)
 145 {
 146         return split_huge_page_to_list(page, NULL);
 147 }
 148 void deferred_split_huge_page(struct page *page);
 149
 150 void __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
 163 void split_huge_pmd_address(struct vm_area_struct *vma, unsigned long address,
 164                 bool freeze, struct page *page);
 165
 166 void __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
 177 extern int hugepage_madvise(struct vm_area_struct *vma,
 178                             unsigned long *vm_flags, int advice);
 179 extern void vma_adjust_trans_huge(struct vm_area_struct *vma,
 180                                     unsigned long start,
 181                                     unsigned long end,
 182                                     long adjust_next);
 183 extern spinlock_t *__pmd_trans_huge_lock(pmd_t *pmd,
 184                 struct vm_area_struct *vma);
 185 extern spinlock_t *__pud_trans_huge_lock(pud_t *pud,
 186                 struct vm_area_struct *vma);
 187
 188 static 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 */
 194 static 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 }
 203 static 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 }
 212 static inline int hpage_nr_pages(struct page *page)
 213 {
 214         if (unlikely(PageTransHuge(page)))
 215                 return HPAGE_PMD_NR;
 216         return 1;
 217 }
 218
 219 struct page *follow_devmap_pmd(struct vm_area_struct *vma, unsigned long addr,
 220                 pmd_t *pmd, int flags);
 221 struct page *follow_devmap_pud(struct vm_area_struct *vma, unsigned long addr,
 222                 pud_t *pud, int flags);
 223
 224 extern vm_fault_t do_huge_pmd_numa_page(struct vm_fault *vmf, pmd_t orig_pmd);
 225
 226 extern struct page *huge_zero_page;
 227 extern unsigned long huge_zero_pfn;
 228
 229 static inline bool is_huge_zero_page(struct page *page)
 230 {
 231         return READ_ONCE(huge_zero_page) == page;
 232 }
 233
 234 static inline bool is_huge_zero_pmd(pmd_t pmd)
 235 {
 236         return READ_ONCE(huge_zero_pfn) == pmd_pfn(pmd) && pmd_present(pmd);
 237 }
 238
 239 static inline bool is_huge_zero_pud(pud_t pud)
 240 {
 241         return false;
 242 }
 243
 244 struct page *mm_get_huge_zero_page(struct mm_struct *mm);
 245 void mm_put_huge_zero_page(struct mm_struct *mm);
 246
 247 #define mk_huge_pmd(page, prot) pmd_mkhuge(mk_pmd(page, prot))
 248
 249 static inline bool thp_migration_supported(void)
 250 {
 251         return IS_ENABLED(CONFIG_ARCH_ENABLE_THP_MIGRATION);
 252 }
 253
 254 #else /* CONFIG_TRANSPARENT_HUGEPAGE */
 255 #define HPAGE_PMD_SHIFT ({ BUILD_BUG(); 0; })
 256 #define HPAGE_PMD_MASK ({ BUILD_BUG(); 0; })
 257 #define HPAGE_PMD_SIZE ({ BUILD_BUG(); 0; })
 258
 259 #define HPAGE_PUD_SHIFT ({ BUILD_BUG(); 0; })
 260 #define HPAGE_PUD_MASK ({ BUILD_BUG(); 0; })
 261 #define HPAGE_PUD_SIZE ({ BUILD_BUG(); 0; })
 262
 263 #define hpage_nr_pages(x) 1
 264
 265 static inline bool __transparent_hugepage_enabled(struct vm_area_struct *vma)
 266 {
 267         return false;
 268 }
 269
 270 static inline bool transparent_hugepage_enabled(struct vm_area_struct *vma)
 271 {
 272         return false;
 273 }
 274
 275 static inline void prep_transhuge_page(struct page *page) {}
 276
 277 #define transparent_hugepage_flags 0UL
 278
 279 #define thp_get_unmapped_area   NULL
 280
 281 static inline bool
 282 can_split_huge_page(struct page *page, int *pextra_pins)
 283 {
 284         BUILD_BUG();
 285         return false;
 286 }
 287 static inline int
 288 split_huge_page_to_list(struct page *page, struct list_head *list)
 289 {
 290         return 0;
 291 }
 292 static inline int split_huge_page(struct page *page)
 293 {
 294         return 0;
 295 }
 296 static inline void deferred_split_huge_page(struct page *page) {}
 297 #define split_huge_pmd(__vma, __pmd, __address) \
 298         do { } while (0)
 299
 300 static inline void __split_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
 301                 unsigned long address, bool freeze, struct page *page) {}
 302 static inline void split_huge_pmd_address(struct vm_area_struct *vma,
 303                 unsigned long address, bool freeze, struct page *page) {}
 304
 305 #define split_huge_pud(__vma, __pmd, __address) \
 306         do { } while (0)
 307
 308 static inline int hugepage_madvise(struct vm_area_struct *vma,
 309                                    unsigned long *vm_flags, int advice)
 310 {
 311         BUG();
 312         return 0;
 313 }
 314 static inline void vma_adjust_trans_huge(struct vm_area_struct *vma,
 315                                          unsigned long start,
 316                                          unsigned long end,
 317                                          long adjust_next)
 318 {
 319 }
 320 static inline int is_swap_pmd(pmd_t pmd)
 321 {
 322         return 0;
 323 }
 324 static inline spinlock_t *pmd_trans_huge_lock(pmd_t *pmd,
 325                 struct vm_area_struct *vma)
 326 {
 327         return NULL;
 328 }
 329 static inline spinlock_t *pud_trans_huge_lock(pud_t *pud,
 330                 struct vm_area_struct *vma)
 331 {
 332         return NULL;
 333 }
 334
 335 static inline vm_fault_t do_huge_pmd_numa_page(struct vm_fault *vmf,
 336                 pmd_t orig_pmd)
 337 {
 338         return 0;
 339 }
 340
 341 static inline bool is_huge_zero_page(struct page *page)
 342 {
 343         return false;
 344 }
 345
 346 static inline bool is_huge_zero_pmd(pmd_t pmd)
 347 {
 348         return false;
 349 }
 350
 351 static inline bool is_huge_zero_pud(pud_t pud)
 352 {
 353         return false;
 354 }
 355
 356 static inline void mm_put_huge_zero_page(struct mm_struct *mm)
 357 {
 358         return;
 359 }
 360
 361 static inline struct page *follow_devmap_pmd(struct vm_area_struct *vma,
 362                 unsigned long addr, pmd_t *pmd, int flags)
 363 {
 364         return NULL;
 365 }
 366
 367 static inline struct page *follow_devmap_pud(struct vm_area_struct *vma,
 368                 unsigned long addr, pud_t *pud, int flags)
 369 {
 370         return NULL;
 371 }
 372
 373 static inline bool thp_migration_supported(void)
 374 {
 375         return false;
 376 }
 377 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 378
 379 #endif /* _LINUX_HUGE_MM_H */