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