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 unsigned long transparent_hugepage_flags;
  91
  92 /*
  93  * to be used on vmas which are known to support THP.
  94  * Use transparent_hugepage_enabled otherwise
  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 (vma_is_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          * For dax vmas, try to always use hugepage mappings. If the kernel does
 111          * not support hugepages, fsdax mappings will fallback to PAGE_SIZE
 112          * mappings, and device-dax namespaces, that try to guarantee a given
 113          * mapping size, will fail to enable
 114          */
 115         if (vma_is_dax(vma))
 116                 return true;
 117
 118         if (transparent_hugepage_flags &
 119                                 (1 << TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG))
 120                 return !!(vma->vm_flags & VM_HUGEPAGE);
 121
 122         return false;
 123 }
 124
 125 bool transparent_hugepage_enabled(struct vm_area_struct *vma);
 126
 127 #define HPAGE_CACHE_INDEX_MASK (HPAGE_PMD_NR - 1)
 128
 129 static inline bool transhuge_vma_suitable(struct vm_area_struct *vma,
 130                 unsigned long haddr)
 131 {
 132         /* Don't have to check pgoff for anonymous vma */
 133         if (!vma_is_anonymous(vma)) {
 134                 if (((vma->vm_start >> PAGE_SHIFT) & HPAGE_CACHE_INDEX_MASK) !=
 135                         (vma->vm_pgoff & HPAGE_CACHE_INDEX_MASK))
 136                         return false;
 137         }
 138
 139         if (haddr < vma->vm_start || haddr + HPAGE_PMD_SIZE > vma->vm_end)
 140                 return false;
 141         return true;
 142 }
 143
 144 #define transparent_hugepage_use_zero_page()                            \
 145         (transparent_hugepage_flags &                                   \
 146          (1<<TRANSPARENT_HUGEPAGE_USE_ZERO_PAGE_FLAG))
 147 #ifdef CONFIG_DEBUG_VM
 148 #define transparent_hugepage_debug_cow()                                \
 149         (transparent_hugepage_flags &                                   \
 150          (1<<TRANSPARENT_HUGEPAGE_DEBUG_COW_FLAG))
 151 #else /* CONFIG_DEBUG_VM */
 152 #define transparent_hugepage_debug_cow() 0
 153 #endif /* CONFIG_DEBUG_VM */
 154
 155 extern unsigned long thp_get_unmapped_area(struct file *filp,
 156                 unsigned long addr, unsigned long len, unsigned long pgoff,
 157                 unsigned long flags);
 158
 159 extern void prep_transhuge_page(struct page *page);
 160 extern void free_transhuge_page(struct page *page);
 161 bool is_transparent_hugepage(struct page *page);
 162
 163 bool can_split_huge_page(struct page *page, int *pextra_pins);
 164 int split_huge_page_to_list(struct page *page, struct list_head *list);
 165 static inline int split_huge_page(struct page *page)
 166 {
 167         return split_huge_page_to_list(page, NULL);
 168 }
 169 void deferred_split_huge_page(struct page *page);
 170
 171 void __split_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
 172                 unsigned long address, bool freeze, struct page *page);
 173
 174 #define split_huge_pmd(__vma, __pmd, __address)                         \
 175         do {                                                            \
 176                 pmd_t *____pmd = (__pmd);                               \
 177                 if (is_swap_pmd(*____pmd) || pmd_trans_huge(*____pmd)   \
 178                                         || pmd_devmap(*____pmd))        \
 179                         __split_huge_pmd(__vma, __pmd, __address,       \
 180                                                 false, NULL);           \
 181         }  while (0)
 182
 183
 184 void split_huge_pmd_address(struct vm_area_struct *vma, unsigned long address,
 185                 bool freeze, struct page *page);
 186
 187 void __split_huge_pud(struct vm_area_struct *vma, pud_t *pud,
 188                 unsigned long address);
 189
 190 #define split_huge_pud(__vma, __pud, __address)                         \
 191         do {                                                            \
 192                 pud_t *____pud = (__pud);                               \
 193                 if (pud_trans_huge(*____pud)                            \
 194                                         || pud_devmap(*____pud))        \
 195                         __split_huge_pud(__vma, __pud, __address);      \
 196         }  while (0)
 197
 198 extern int hugepage_madvise(struct vm_area_struct *vma,
 199                             unsigned long *vm_flags, int advice);
 200 extern void vma_adjust_trans_huge(struct vm_area_struct *vma,
 201                                     unsigned long start,
 202                                     unsigned long end,
 203                                     long adjust_next);
 204 extern spinlock_t *__pmd_trans_huge_lock(pmd_t *pmd,
 205                 struct vm_area_struct *vma);
 206 extern spinlock_t *__pud_trans_huge_lock(pud_t *pud,
 207                 struct vm_area_struct *vma);
 208
 209 static inline int is_swap_pmd(pmd_t pmd)
 210 {
 211         return !pmd_none(pmd) && !pmd_present(pmd);
 212 }
 213
 214 /* mmap_sem must be held on entry */
 215 static inline spinlock_t *pmd_trans_huge_lock(pmd_t *pmd,
 216                 struct vm_area_struct *vma)
 217 {
 218         if (is_swap_pmd(*pmd) || pmd_trans_huge(*pmd) || pmd_devmap(*pmd))
 219                 return __pmd_trans_huge_lock(pmd, vma);
 220         else
 221                 return NULL;
 222 }
 223 static inline spinlock_t *pud_trans_huge_lock(pud_t *pud,
 224                 struct vm_area_struct *vma)
 225 {
 226         if (pud_trans_huge(*pud) || pud_devmap(*pud))
 227                 return __pud_trans_huge_lock(pud, vma);
 228         else
 229                 return NULL;
 230 }
 231 static inline int hpage_nr_pages(struct page *page)
 232 {
 233         if (unlikely(PageTransHuge(page)))
 234                 return HPAGE_PMD_NR;
 235         return 1;
 236 }
 237
 238 struct page *follow_devmap_pmd(struct vm_area_struct *vma, unsigned long addr,
 239                 pmd_t *pmd, int flags, struct dev_pagemap **pgmap);
 240 struct page *follow_devmap_pud(struct vm_area_struct *vma, unsigned long addr,
 241                 pud_t *pud, int flags, struct dev_pagemap **pgmap);
 242
 243 extern vm_fault_t do_huge_pmd_numa_page(struct vm_fault *vmf, pmd_t orig_pmd);
 244
 245 extern struct page *huge_zero_page;
 246
 247 static inline bool is_huge_zero_page(struct page *page)
 248 {
 249         return READ_ONCE(huge_zero_page) == page;
 250 }
 251
 252 static inline bool is_huge_zero_pmd(pmd_t pmd)
 253 {
 254         return is_huge_zero_page(pmd_page(pmd));
 255 }
 256
 257 static inline bool is_huge_zero_pud(pud_t pud)
 258 {
 259         return false;
 260 }
 261
 262 struct page *mm_get_huge_zero_page(struct mm_struct *mm);
 263 void mm_put_huge_zero_page(struct mm_struct *mm);
 264
 265 #define mk_huge_pmd(page, prot) pmd_mkhuge(mk_pmd(page, prot))
 266
 267 static inline bool thp_migration_supported(void)
 268 {
 269         return IS_ENABLED(CONFIG_ARCH_ENABLE_THP_MIGRATION);
 270 }
 271
 272 static inline struct list_head *page_deferred_list(struct page *page)
 273 {
 274         /*
 275          * Global or memcg deferred list in the second tail pages is
 276          * occupied by compound_head.
 277          */
 278         return &page[2].deferred_list;
 279 }
 280
 281 #else /* CONFIG_TRANSPARENT_HUGEPAGE */
 282 #define HPAGE_PMD_SHIFT ({ BUILD_BUG(); 0; })
 283 #define HPAGE_PMD_MASK ({ BUILD_BUG(); 0; })
 284 #define HPAGE_PMD_SIZE ({ BUILD_BUG(); 0; })
 285
 286 #define HPAGE_PUD_SHIFT ({ BUILD_BUG(); 0; })
 287 #define HPAGE_PUD_MASK ({ BUILD_BUG(); 0; })
 288 #define HPAGE_PUD_SIZE ({ BUILD_BUG(); 0; })
 289
 290 #define hpage_nr_pages(x) 1
 291
 292 static inline bool __transparent_hugepage_enabled(struct vm_area_struct *vma)
 293 {
 294         return false;
 295 }
 296
 297 static inline bool transparent_hugepage_enabled(struct vm_area_struct *vma)
 298 {
 299         return false;
 300 }
 301
 302 static inline bool transhuge_vma_suitable(struct vm_area_struct *vma,
 303                 unsigned long haddr)
 304 {
 305         return false;
 306 }
 307
 308 static inline void prep_transhuge_page(struct page *page) {}
 309
 310 static inline bool is_transparent_hugepage(struct page *page)
 311 {
 312         return false;
 313 }
 314
 315 #define transparent_hugepage_flags 0UL
 316
 317 #define thp_get_unmapped_area   NULL
 318
 319 static inline bool
 320 can_split_huge_page(struct page *page, int *pextra_pins)
 321 {
 322         BUILD_BUG();
 323         return false;
 324 }
 325 static inline int
 326 split_huge_page_to_list(struct page *page, struct list_head *list)
 327 {
 328         return 0;
 329 }
 330 static inline int split_huge_page(struct page *page)
 331 {
 332         return 0;
 333 }
 334 static inline void deferred_split_huge_page(struct page *page) {}
 335 #define split_huge_pmd(__vma, __pmd, __address) \
 336         do { } while (0)
 337
 338 static inline void __split_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
 339                 unsigned long address, bool freeze, struct page *page) {}
 340 static inline void split_huge_pmd_address(struct vm_area_struct *vma,
 341                 unsigned long address, bool freeze, struct page *page) {}
 342
 343 #define split_huge_pud(__vma, __pmd, __address) \
 344         do { } while (0)
 345
 346 static inline int hugepage_madvise(struct vm_area_struct *vma,
 347                                    unsigned long *vm_flags, int advice)
 348 {
 349         BUG();
 350         return 0;
 351 }
 352 static inline void vma_adjust_trans_huge(struct vm_area_struct *vma,
 353                                          unsigned long start,
 354                                          unsigned long end,
 355                                          long adjust_next)
 356 {
 357 }
 358 static inline int is_swap_pmd(pmd_t pmd)
 359 {
 360         return 0;
 361 }
 362 static inline spinlock_t *pmd_trans_huge_lock(pmd_t *pmd,
 363                 struct vm_area_struct *vma)
 364 {
 365         return NULL;
 366 }
 367 static inline spinlock_t *pud_trans_huge_lock(pud_t *pud,
 368                 struct vm_area_struct *vma)
 369 {
 370         return NULL;
 371 }
 372
 373 static inline vm_fault_t do_huge_pmd_numa_page(struct vm_fault *vmf,
 374                 pmd_t orig_pmd)
 375 {
 376         return 0;
 377 }
 378
 379 static inline bool is_huge_zero_page(struct page *page)
 380 {
 381         return false;
 382 }
 383
 384 static inline bool is_huge_zero_pud(pud_t pud)
 385 {
 386         return false;
 387 }
 388
 389 static inline void mm_put_huge_zero_page(struct mm_struct *mm)
 390 {
 391         return;
 392 }
 393
 394 static inline struct page *follow_devmap_pmd(struct vm_area_struct *vma,
 395         unsigned long addr, pmd_t *pmd, int flags, struct dev_pagemap **pgmap)
 396 {
 397         return NULL;
 398 }
 399
 400 static inline struct page *follow_devmap_pud(struct vm_area_struct *vma,
 401         unsigned long addr, pud_t *pud, int flags, struct dev_pagemap **pgmap)
 402 {
 403         return NULL;
 404 }
 405
 406 static inline bool thp_migration_supported(void)
 407 {
 408         return false;
 409 }
 410 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 411
 412 #endif /* _LINUX_HUGE_MM_H */