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 vm_fault_t do_huge_pmd_anonymous_page(struct vm_fault *vmf);
  11 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 *dst_vma, struct vm_area_struct *src_vma);
  14 void huge_pmd_set_accessed(struct vm_fault *vmf);
  15 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 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 vm_fault_t do_huge_pmd_wp_page(struct vm_fault *vmf);
  28 struct page *follow_trans_huge_pmd(struct vm_area_struct *vma,
  29                                    unsigned long addr, pmd_t *pmd,
  30                                    unsigned int flags);
  31 bool madvise_free_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma,
  32                            pmd_t *pmd, unsigned long addr, unsigned long next);
  33 int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma, pmd_t *pmd,
  34                  unsigned long addr);
  35 int zap_huge_pud(struct mmu_gather *tlb, struct vm_area_struct *vma, pud_t *pud,
  36                  unsigned long addr);
  37 bool move_huge_pmd(struct vm_area_struct *vma, unsigned long old_addr,
  38                    unsigned long new_addr, pmd_t *old_pmd, pmd_t *new_pmd);
  39 int change_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd, unsigned long addr,
  40                     pgprot_t newprot, unsigned long cp_flags);
  41 vm_fault_t vmf_insert_pfn_pmd_prot(struct vm_fault *vmf, pfn_t pfn,
  42                                    pgprot_t pgprot, bool write);
  43
  44 /**
  45  * vmf_insert_pfn_pmd - insert a pmd size pfn
  46  * @vmf: Structure describing the fault
  47  * @pfn: pfn to insert
  48  * @pgprot: page protection to use
  49  * @write: whether it's a write fault
  50  *
  51  * Insert a pmd size pfn. See vmf_insert_pfn() for additional info.
  52  *
  53  * Return: vm_fault_t value.
  54  */
  55 static inline vm_fault_t vmf_insert_pfn_pmd(struct vm_fault *vmf, pfn_t pfn,
  56                                             bool write)
  57 {
  58         return vmf_insert_pfn_pmd_prot(vmf, pfn, vmf->vma->vm_page_prot, write);
  59 }
  60 vm_fault_t vmf_insert_pfn_pud_prot(struct vm_fault *vmf, pfn_t pfn,
  61                                    pgprot_t pgprot, bool write);
  62
  63 /**
  64  * vmf_insert_pfn_pud - insert a pud size pfn
  65  * @vmf: Structure describing the fault
  66  * @pfn: pfn to insert
  67  * @pgprot: page protection to use
  68  * @write: whether it's a write fault
  69  *
  70  * Insert a pud size pfn. See vmf_insert_pfn() for additional info.
  71  *
  72  * Return: vm_fault_t value.
  73  */
  74 static inline vm_fault_t vmf_insert_pfn_pud(struct vm_fault *vmf, pfn_t pfn,
  75                                             bool write)
  76 {
  77         return vmf_insert_pfn_pud_prot(vmf, pfn, vmf->vma->vm_page_prot, write);
  78 }
  79
  80 enum transparent_hugepage_flag {
  81         TRANSPARENT_HUGEPAGE_NEVER_DAX,
  82         TRANSPARENT_HUGEPAGE_FLAG,
  83         TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG,
  84         TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG,
  85         TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_FLAG,
  86         TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG,
  87         TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG,
  88         TRANSPARENT_HUGEPAGE_DEFRAG_KHUGEPAGED_FLAG,
  89         TRANSPARENT_HUGEPAGE_USE_ZERO_PAGE_FLAG,
  90 };
  91
  92 struct kobject;
  93 struct kobj_attribute;
  94
  95 ssize_t single_hugepage_flag_store(struct kobject *kobj,
  96                                    struct kobj_attribute *attr,
  97                                    const char *buf, size_t count,
  98                                    enum transparent_hugepage_flag flag);
  99 ssize_t single_hugepage_flag_show(struct kobject *kobj,
 100                                   struct kobj_attribute *attr, char *buf,
 101                                   enum transparent_hugepage_flag flag);
 102 extern struct kobj_attribute shmem_enabled_attr;
 103
 104 #define HPAGE_PMD_ORDER (HPAGE_PMD_SHIFT-PAGE_SHIFT)
 105 #define HPAGE_PMD_NR (1<<HPAGE_PMD_ORDER)
 106
 107 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 108 #define HPAGE_PMD_SHIFT PMD_SHIFT
 109 #define HPAGE_PMD_SIZE  ((1UL) << HPAGE_PMD_SHIFT)
 110 #define HPAGE_PMD_MASK  (~(HPAGE_PMD_SIZE - 1))
 111
 112 #define HPAGE_PUD_SHIFT PUD_SHIFT
 113 #define HPAGE_PUD_SIZE  ((1UL) << HPAGE_PUD_SHIFT)
 114 #define HPAGE_PUD_MASK  (~(HPAGE_PUD_SIZE - 1))
 115
 116 extern unsigned long transparent_hugepage_flags;
 117
 118 static inline bool transhuge_vma_suitable(struct vm_area_struct *vma,
 119                 unsigned long haddr)
 120 {
 121         /* Don't have to check pgoff for anonymous vma */
 122         if (!vma_is_anonymous(vma)) {
 123                 if (!IS_ALIGNED((vma->vm_start >> PAGE_SHIFT) - vma->vm_pgoff,
 124                                 HPAGE_PMD_NR))
 125                         return false;
 126         }
 127
 128         if (haddr < vma->vm_start || haddr + HPAGE_PMD_SIZE > vma->vm_end)
 129                 return false;
 130         return true;
 131 }
 132
 133 static inline bool transhuge_vma_enabled(struct vm_area_struct *vma,
 134                                           unsigned long vm_flags)
 135 {
 136         /* Explicitly disabled through madvise. */
 137         if ((vm_flags & VM_NOHUGEPAGE) ||
 138             test_bit(MMF_DISABLE_THP, &vma->vm_mm->flags))
 139                 return false;
 140         return true;
 141 }
 142
 143 /*
 144  * to be used on vmas which are known to support THP.
 145  * Use transparent_hugepage_active otherwise
 146  */
 147 static inline bool __transparent_hugepage_enabled(struct vm_area_struct *vma)
 148 {
 149
 150         /*
 151          * If the hardware/firmware marked hugepage support disabled.
 152          */
 153         if (transparent_hugepage_flags & (1 << TRANSPARENT_HUGEPAGE_NEVER_DAX))
 154                 return false;
 155
 156         if (!transhuge_vma_enabled(vma, vma->vm_flags))
 157                 return false;
 158
 159         if (vma_is_temporary_stack(vma))
 160                 return false;
 161
 162         if (transparent_hugepage_flags & (1 << TRANSPARENT_HUGEPAGE_FLAG))
 163                 return true;
 164
 165         if (vma_is_dax(vma))
 166                 return true;
 167
 168         if (transparent_hugepage_flags &
 169                                 (1 << TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG))
 170                 return !!(vma->vm_flags & VM_HUGEPAGE);
 171
 172         return false;
 173 }
 174
 175 bool transparent_hugepage_active(struct vm_area_struct *vma);
 176
 177 #define transparent_hugepage_use_zero_page()                            \
 178         (transparent_hugepage_flags &                                   \
 179          (1<<TRANSPARENT_HUGEPAGE_USE_ZERO_PAGE_FLAG))
 180
 181 unsigned long thp_get_unmapped_area(struct file *filp, unsigned long addr,
 182                 unsigned long len, unsigned long pgoff, unsigned long flags);
 183
 184 void prep_transhuge_page(struct page *page);
 185 void free_transhuge_page(struct page *page);
 186 bool is_transparent_hugepage(struct page *page);
 187
 188 bool can_split_huge_page(struct page *page, int *pextra_pins);
 189 int split_huge_page_to_list(struct page *page, struct list_head *list);
 190 static inline int split_huge_page(struct page *page)
 191 {
 192         return split_huge_page_to_list(page, NULL);
 193 }
 194 void deferred_split_huge_page(struct page *page);
 195
 196 void __split_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
 197                 unsigned long address, bool freeze, struct page *page);
 198
 199 #define split_huge_pmd(__vma, __pmd, __address)                         \
 200         do {                                                            \
 201                 pmd_t *____pmd = (__pmd);                               \
 202                 if (is_swap_pmd(*____pmd) || pmd_trans_huge(*____pmd)   \
 203                                         || pmd_devmap(*____pmd))        \
 204                         __split_huge_pmd(__vma, __pmd, __address,       \
 205                                                 false, NULL);           \
 206         }  while (0)
 207
 208
 209 void split_huge_pmd_address(struct vm_area_struct *vma, unsigned long address,
 210                 bool freeze, struct page *page);
 211
 212 void __split_huge_pud(struct vm_area_struct *vma, pud_t *pud,
 213                 unsigned long address);
 214
 215 #define split_huge_pud(__vma, __pud, __address)                         \
 216         do {                                                            \
 217                 pud_t *____pud = (__pud);                               \
 218                 if (pud_trans_huge(*____pud)                            \
 219                                         || pud_devmap(*____pud))        \
 220                         __split_huge_pud(__vma, __pud, __address);      \
 221         }  while (0)
 222
 223 int hugepage_madvise(struct vm_area_struct *vma, unsigned long *vm_flags,
 224                      int advice);
 225 void vma_adjust_trans_huge(struct vm_area_struct *vma, unsigned long start,
 226                            unsigned long end, long adjust_next);
 227 spinlock_t *__pmd_trans_huge_lock(pmd_t *pmd, struct vm_area_struct *vma);
 228 spinlock_t *__pud_trans_huge_lock(pud_t *pud, struct vm_area_struct *vma);
 229
 230 static inline int is_swap_pmd(pmd_t pmd)
 231 {
 232         return !pmd_none(pmd) && !pmd_present(pmd);
 233 }
 234
 235 /* mmap_lock must be held on entry */
 236 static inline spinlock_t *pmd_trans_huge_lock(pmd_t *pmd,
 237                 struct vm_area_struct *vma)
 238 {
 239         if (is_swap_pmd(*pmd) || pmd_trans_huge(*pmd) || pmd_devmap(*pmd))
 240                 return __pmd_trans_huge_lock(pmd, vma);
 241         else
 242                 return NULL;
 243 }
 244 static inline spinlock_t *pud_trans_huge_lock(pud_t *pud,
 245                 struct vm_area_struct *vma)
 246 {
 247         if (pud_trans_huge(*pud) || pud_devmap(*pud))
 248                 return __pud_trans_huge_lock(pud, vma);
 249         else
 250                 return NULL;
 251 }
 252
 253 /**
 254  * thp_order - Order of a transparent huge page.
 255  * @page: Head page of a transparent huge page.
 256  */
 257 static inline unsigned int thp_order(struct page *page)
 258 {
 259         VM_BUG_ON_PGFLAGS(PageTail(page), page);
 260         if (PageHead(page))
 261                 return HPAGE_PMD_ORDER;
 262         return 0;
 263 }
 264
 265 /**
 266  * thp_nr_pages - The number of regular pages in this huge page.
 267  * @page: The head page of a huge page.
 268  */
 269 static inline int thp_nr_pages(struct page *page)
 270 {
 271         VM_BUG_ON_PGFLAGS(PageTail(page), page);
 272         if (PageHead(page))
 273                 return HPAGE_PMD_NR;
 274         return 1;
 275 }
 276
 277 struct page *follow_devmap_pmd(struct vm_area_struct *vma, unsigned long addr,
 278                 pmd_t *pmd, int flags, struct dev_pagemap **pgmap);
 279 struct page *follow_devmap_pud(struct vm_area_struct *vma, unsigned long addr,
 280                 pud_t *pud, int flags, struct dev_pagemap **pgmap);
 281
 282 vm_fault_t do_huge_pmd_numa_page(struct vm_fault *vmf);
 283
 284 extern struct page *huge_zero_page;
 285 extern unsigned long huge_zero_pfn;
 286
 287 static inline bool is_huge_zero_page(struct page *page)
 288 {
 289         return READ_ONCE(huge_zero_page) == page;
 290 }
 291
 292 static inline bool is_huge_zero_pmd(pmd_t pmd)
 293 {
 294         return READ_ONCE(huge_zero_pfn) == pmd_pfn(pmd) && pmd_present(pmd);
 295 }
 296
 297 static inline bool is_huge_zero_pud(pud_t pud)
 298 {
 299         return false;
 300 }
 301
 302 struct page *mm_get_huge_zero_page(struct mm_struct *mm);
 303 void mm_put_huge_zero_page(struct mm_struct *mm);
 304
 305 #define mk_huge_pmd(page, prot) pmd_mkhuge(mk_pmd(page, prot))
 306
 307 static inline bool thp_migration_supported(void)
 308 {
 309         return IS_ENABLED(CONFIG_ARCH_ENABLE_THP_MIGRATION);
 310 }
 311
 312 static inline struct list_head *page_deferred_list(struct page *page)
 313 {
 314         /*
 315          * Global or memcg deferred list in the second tail pages is
 316          * occupied by compound_head.
 317          */
 318         return &page[2].deferred_list;
 319 }
 320
 321 #else /* CONFIG_TRANSPARENT_HUGEPAGE */
 322 #define HPAGE_PMD_SHIFT ({ BUILD_BUG(); 0; })
 323 #define HPAGE_PMD_MASK ({ BUILD_BUG(); 0; })
 324 #define HPAGE_PMD_SIZE ({ BUILD_BUG(); 0; })
 325
 326 #define HPAGE_PUD_SHIFT ({ BUILD_BUG(); 0; })
 327 #define HPAGE_PUD_MASK ({ BUILD_BUG(); 0; })
 328 #define HPAGE_PUD_SIZE ({ BUILD_BUG(); 0; })
 329
 330 static inline unsigned int thp_order(struct page *page)
 331 {
 332         VM_BUG_ON_PGFLAGS(PageTail(page), page);
 333         return 0;
 334 }
 335
 336 static inline int thp_nr_pages(struct page *page)
 337 {
 338         VM_BUG_ON_PGFLAGS(PageTail(page), page);
 339         return 1;
 340 }
 341
 342 static inline bool __transparent_hugepage_enabled(struct vm_area_struct *vma)
 343 {
 344         return false;
 345 }
 346
 347 static inline bool transparent_hugepage_active(struct vm_area_struct *vma)
 348 {
 349         return false;
 350 }
 351
 352 static inline bool transhuge_vma_suitable(struct vm_area_struct *vma,
 353                 unsigned long haddr)
 354 {
 355         return false;
 356 }
 357
 358 static inline bool transhuge_vma_enabled(struct vm_area_struct *vma,
 359                                           unsigned long vm_flags)
 360 {
 361         return false;
 362 }
 363
 364 static inline void prep_transhuge_page(struct page *page) {}
 365
 366 static inline bool is_transparent_hugepage(struct page *page)
 367 {
 368         return false;
 369 }
 370
 371 #define transparent_hugepage_flags 0UL
 372
 373 #define thp_get_unmapped_area   NULL
 374
 375 static inline bool
 376 can_split_huge_page(struct page *page, int *pextra_pins)
 377 {
 378         BUILD_BUG();
 379         return false;
 380 }
 381 static inline int
 382 split_huge_page_to_list(struct page *page, struct list_head *list)
 383 {
 384         return 0;
 385 }
 386 static inline int split_huge_page(struct page *page)
 387 {
 388         return 0;
 389 }
 390 static inline void deferred_split_huge_page(struct page *page) {}
 391 #define split_huge_pmd(__vma, __pmd, __address) \
 392         do { } while (0)
 393
 394 static inline void __split_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
 395                 unsigned long address, bool freeze, struct page *page) {}
 396 static inline void split_huge_pmd_address(struct vm_area_struct *vma,
 397                 unsigned long address, bool freeze, struct page *page) {}
 398
 399 #define split_huge_pud(__vma, __pmd, __address) \
 400         do { } while (0)
 401
 402 static inline int hugepage_madvise(struct vm_area_struct *vma,
 403                                    unsigned long *vm_flags, int advice)
 404 {
 405         BUG();
 406         return 0;
 407 }
 408 static inline void vma_adjust_trans_huge(struct vm_area_struct *vma,
 409                                          unsigned long start,
 410                                          unsigned long end,
 411                                          long adjust_next)
 412 {
 413 }
 414 static inline int is_swap_pmd(pmd_t pmd)
 415 {
 416         return 0;
 417 }
 418 static inline spinlock_t *pmd_trans_huge_lock(pmd_t *pmd,
 419                 struct vm_area_struct *vma)
 420 {
 421         return NULL;
 422 }
 423 static inline spinlock_t *pud_trans_huge_lock(pud_t *pud,
 424                 struct vm_area_struct *vma)
 425 {
 426         return NULL;
 427 }
 428
 429 static inline vm_fault_t do_huge_pmd_numa_page(struct vm_fault *vmf)
 430 {
 431         return 0;
 432 }
 433
 434 static inline bool is_huge_zero_page(struct page *page)
 435 {
 436         return false;
 437 }
 438
 439 static inline bool is_huge_zero_pmd(pmd_t pmd)
 440 {
 441         return false;
 442 }
 443
 444 static inline bool is_huge_zero_pud(pud_t pud)
 445 {
 446         return false;
 447 }
 448
 449 static inline void mm_put_huge_zero_page(struct mm_struct *mm)
 450 {
 451         return;
 452 }
 453
 454 static inline struct page *follow_devmap_pmd(struct vm_area_struct *vma,
 455         unsigned long addr, pmd_t *pmd, int flags, struct dev_pagemap **pgmap)
 456 {
 457         return NULL;
 458 }
 459
 460 static inline struct page *follow_devmap_pud(struct vm_area_struct *vma,
 461         unsigned long addr, pud_t *pud, int flags, struct dev_pagemap **pgmap)
 462 {
 463         return NULL;
 464 }
 465
 466 static inline bool thp_migration_supported(void)
 467 {
 468         return false;
 469 }
 470 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 471
 472 /**
 473  * thp_size - Size of a transparent huge page.
 474  * @page: Head page of a transparent huge page.
 475  *
 476  * Return: Number of bytes in this page.
 477  */
 478 static inline unsigned long thp_size(struct page *page)
 479 {
 480         return PAGE_SIZE << thp_order(page);
 481 }
 482
 483 #endif /* _LINUX_HUGE_MM_H */