xref: /linux-6.15/include/linux/hugetlb.h (revision fdd20ec8)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_HUGETLB_H
3 #define _LINUX_HUGETLB_H
4 
5 #include <linux/mm_types.h>
6 #include <linux/mmdebug.h>
7 #include <linux/fs.h>
8 #include <linux/hugetlb_inline.h>
9 #include <linux/cgroup.h>
10 #include <linux/list.h>
11 #include <linux/kref.h>
12 #include <asm/pgtable.h>
13 
14 struct ctl_table;
15 struct user_struct;
16 struct mmu_gather;
17 
18 #ifndef is_hugepd
19 /*
20  * Some architectures requires a hugepage directory format that is
21  * required to support multiple hugepage sizes. For example
22  * a4fe3ce76 "powerpc/mm: Allow more flexible layouts for hugepage pagetables"
23  * introduced the same on powerpc. This allows for a more flexible hugepage
24  * pagetable layout.
25  */
26 typedef struct { unsigned long pd; } hugepd_t;
27 #define is_hugepd(hugepd) (0)
28 #define __hugepd(x) ((hugepd_t) { (x) })
29 static inline int gup_huge_pd(hugepd_t hugepd, unsigned long addr,
30 			      unsigned pdshift, unsigned long end,
31 			      int write, struct page **pages, int *nr)
32 {
33 	return 0;
34 }
35 #else
36 extern int gup_huge_pd(hugepd_t hugepd, unsigned long addr,
37 		       unsigned pdshift, unsigned long end,
38 		       int write, struct page **pages, int *nr);
39 #endif
40 
41 
42 #ifdef CONFIG_HUGETLB_PAGE
43 
44 #include <linux/mempolicy.h>
45 #include <linux/shm.h>
46 #include <asm/tlbflush.h>
47 
48 struct hugepage_subpool {
49 	spinlock_t lock;
50 	long count;
51 	long max_hpages;	/* Maximum huge pages or -1 if no maximum. */
52 	long used_hpages;	/* Used count against maximum, includes */
53 				/* both alloced and reserved pages. */
54 	struct hstate *hstate;
55 	long min_hpages;	/* Minimum huge pages or -1 if no minimum. */
56 	long rsv_hpages;	/* Pages reserved against global pool to */
57 				/* sasitfy minimum size. */
58 };
59 
60 struct resv_map {
61 	struct kref refs;
62 	spinlock_t lock;
63 	struct list_head regions;
64 	long adds_in_progress;
65 	struct list_head region_cache;
66 	long region_cache_count;
67 };
68 extern struct resv_map *resv_map_alloc(void);
69 void resv_map_release(struct kref *ref);
70 
71 extern spinlock_t hugetlb_lock;
72 extern int hugetlb_max_hstate __read_mostly;
73 #define for_each_hstate(h) \
74 	for ((h) = hstates; (h) < &hstates[hugetlb_max_hstate]; (h)++)
75 
76 struct hugepage_subpool *hugepage_new_subpool(struct hstate *h, long max_hpages,
77 						long min_hpages);
78 void hugepage_put_subpool(struct hugepage_subpool *spool);
79 
80 void reset_vma_resv_huge_pages(struct vm_area_struct *vma);
81 int hugetlb_sysctl_handler(struct ctl_table *, int, void __user *, size_t *, loff_t *);
82 int hugetlb_overcommit_handler(struct ctl_table *, int, void __user *, size_t *, loff_t *);
83 int hugetlb_treat_movable_handler(struct ctl_table *, int, void __user *, size_t *, loff_t *);
84 
85 #ifdef CONFIG_NUMA
86 int hugetlb_mempolicy_sysctl_handler(struct ctl_table *, int,
87 					void __user *, size_t *, loff_t *);
88 #endif
89 
90 int copy_hugetlb_page_range(struct mm_struct *, struct mm_struct *, struct vm_area_struct *);
91 long follow_hugetlb_page(struct mm_struct *, struct vm_area_struct *,
92 			 struct page **, struct vm_area_struct **,
93 			 unsigned long *, unsigned long *, long, unsigned int,
94 			 int *);
95 void unmap_hugepage_range(struct vm_area_struct *,
96 			  unsigned long, unsigned long, struct page *);
97 void __unmap_hugepage_range_final(struct mmu_gather *tlb,
98 			  struct vm_area_struct *vma,
99 			  unsigned long start, unsigned long end,
100 			  struct page *ref_page);
101 void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct *vma,
102 				unsigned long start, unsigned long end,
103 				struct page *ref_page);
104 void hugetlb_report_meminfo(struct seq_file *);
105 int hugetlb_report_node_meminfo(int, char *);
106 void hugetlb_show_meminfo(void);
107 unsigned long hugetlb_total_pages(void);
108 vm_fault_t hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
109 			unsigned long address, unsigned int flags);
110 int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm, pte_t *dst_pte,
111 				struct vm_area_struct *dst_vma,
112 				unsigned long dst_addr,
113 				unsigned long src_addr,
114 				struct page **pagep);
115 int hugetlb_reserve_pages(struct inode *inode, long from, long to,
116 						struct vm_area_struct *vma,
117 						vm_flags_t vm_flags);
118 long hugetlb_unreserve_pages(struct inode *inode, long start, long end,
119 						long freed);
120 bool isolate_huge_page(struct page *page, struct list_head *list);
121 void putback_active_hugepage(struct page *page);
122 void move_hugetlb_state(struct page *oldpage, struct page *newpage, int reason);
123 void free_huge_page(struct page *page);
124 void hugetlb_fix_reserve_counts(struct inode *inode);
125 extern struct mutex *hugetlb_fault_mutex_table;
126 u32 hugetlb_fault_mutex_hash(struct hstate *h, struct mm_struct *mm,
127 				struct vm_area_struct *vma,
128 				struct address_space *mapping,
129 				pgoff_t idx, unsigned long address);
130 
131 pte_t *huge_pmd_share(struct mm_struct *mm, unsigned long addr, pud_t *pud);
132 
133 extern int sysctl_hugetlb_shm_group;
134 extern struct list_head huge_boot_pages;
135 
136 /* arch callbacks */
137 
138 pte_t *huge_pte_alloc(struct mm_struct *mm,
139 			unsigned long addr, unsigned long sz);
140 pte_t *huge_pte_offset(struct mm_struct *mm,
141 		       unsigned long addr, unsigned long sz);
142 int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep);
143 void adjust_range_if_pmd_sharing_possible(struct vm_area_struct *vma,
144 				unsigned long *start, unsigned long *end);
145 struct page *follow_huge_addr(struct mm_struct *mm, unsigned long address,
146 			      int write);
147 struct page *follow_huge_pd(struct vm_area_struct *vma,
148 			    unsigned long address, hugepd_t hpd,
149 			    int flags, int pdshift);
150 struct page *follow_huge_pmd(struct mm_struct *mm, unsigned long address,
151 				pmd_t *pmd, int flags);
152 struct page *follow_huge_pud(struct mm_struct *mm, unsigned long address,
153 				pud_t *pud, int flags);
154 struct page *follow_huge_pgd(struct mm_struct *mm, unsigned long address,
155 			     pgd_t *pgd, int flags);
156 
157 int pmd_huge(pmd_t pmd);
158 int pud_huge(pud_t pud);
159 unsigned long hugetlb_change_protection(struct vm_area_struct *vma,
160 		unsigned long address, unsigned long end, pgprot_t newprot);
161 
162 bool is_hugetlb_entry_migration(pte_t pte);
163 
164 #else /* !CONFIG_HUGETLB_PAGE */
165 
166 static inline void reset_vma_resv_huge_pages(struct vm_area_struct *vma)
167 {
168 }
169 
170 static inline unsigned long hugetlb_total_pages(void)
171 {
172 	return 0;
173 }
174 
175 static inline int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr,
176 					pte_t *ptep)
177 {
178 	return 0;
179 }
180 
181 static inline void adjust_range_if_pmd_sharing_possible(
182 				struct vm_area_struct *vma,
183 				unsigned long *start, unsigned long *end)
184 {
185 }
186 
187 #define follow_hugetlb_page(m,v,p,vs,a,b,i,w,n)	({ BUG(); 0; })
188 #define follow_huge_addr(mm, addr, write)	ERR_PTR(-EINVAL)
189 #define copy_hugetlb_page_range(src, dst, vma)	({ BUG(); 0; })
190 static inline void hugetlb_report_meminfo(struct seq_file *m)
191 {
192 }
193 #define hugetlb_report_node_meminfo(n, buf)	0
194 static inline void hugetlb_show_meminfo(void)
195 {
196 }
197 #define follow_huge_pd(vma, addr, hpd, flags, pdshift) NULL
198 #define follow_huge_pmd(mm, addr, pmd, flags)	NULL
199 #define follow_huge_pud(mm, addr, pud, flags)	NULL
200 #define follow_huge_pgd(mm, addr, pgd, flags)	NULL
201 #define prepare_hugepage_range(file, addr, len)	(-EINVAL)
202 #define pmd_huge(x)	0
203 #define pud_huge(x)	0
204 #define is_hugepage_only_range(mm, addr, len)	0
205 #define hugetlb_free_pgd_range(tlb, addr, end, floor, ceiling) ({BUG(); 0; })
206 #define hugetlb_fault(mm, vma, addr, flags)	({ BUG(); 0; })
207 #define hugetlb_mcopy_atomic_pte(dst_mm, dst_pte, dst_vma, dst_addr, \
208 				src_addr, pagep)	({ BUG(); 0; })
209 #define huge_pte_offset(mm, address, sz)	0
210 
211 static inline bool isolate_huge_page(struct page *page, struct list_head *list)
212 {
213 	return false;
214 }
215 #define putback_active_hugepage(p)	do {} while (0)
216 #define move_hugetlb_state(old, new, reason)	do {} while (0)
217 
218 static inline unsigned long hugetlb_change_protection(struct vm_area_struct *vma,
219 		unsigned long address, unsigned long end, pgprot_t newprot)
220 {
221 	return 0;
222 }
223 
224 static inline void __unmap_hugepage_range_final(struct mmu_gather *tlb,
225 			struct vm_area_struct *vma, unsigned long start,
226 			unsigned long end, struct page *ref_page)
227 {
228 	BUG();
229 }
230 
231 static inline void __unmap_hugepage_range(struct mmu_gather *tlb,
232 			struct vm_area_struct *vma, unsigned long start,
233 			unsigned long end, struct page *ref_page)
234 {
235 	BUG();
236 }
237 
238 #endif /* !CONFIG_HUGETLB_PAGE */
239 /*
240  * hugepages at page global directory. If arch support
241  * hugepages at pgd level, they need to define this.
242  */
243 #ifndef pgd_huge
244 #define pgd_huge(x)	0
245 #endif
246 #ifndef p4d_huge
247 #define p4d_huge(x)	0
248 #endif
249 
250 #ifndef pgd_write
251 static inline int pgd_write(pgd_t pgd)
252 {
253 	BUG();
254 	return 0;
255 }
256 #endif
257 
258 #define HUGETLB_ANON_FILE "anon_hugepage"
259 
260 enum {
261 	/*
262 	 * The file will be used as an shm file so shmfs accounting rules
263 	 * apply
264 	 */
265 	HUGETLB_SHMFS_INODE     = 1,
266 	/*
267 	 * The file is being created on the internal vfs mount and shmfs
268 	 * accounting rules do not apply
269 	 */
270 	HUGETLB_ANONHUGE_INODE  = 2,
271 };
272 
273 #ifdef CONFIG_HUGETLBFS
274 struct hugetlbfs_sb_info {
275 	long	max_inodes;   /* inodes allowed */
276 	long	free_inodes;  /* inodes free */
277 	spinlock_t	stat_lock;
278 	struct hstate *hstate;
279 	struct hugepage_subpool *spool;
280 	kuid_t	uid;
281 	kgid_t	gid;
282 	umode_t mode;
283 };
284 
285 static inline struct hugetlbfs_sb_info *HUGETLBFS_SB(struct super_block *sb)
286 {
287 	return sb->s_fs_info;
288 }
289 
290 struct hugetlbfs_inode_info {
291 	struct shared_policy policy;
292 	struct inode vfs_inode;
293 	unsigned int seals;
294 };
295 
296 static inline struct hugetlbfs_inode_info *HUGETLBFS_I(struct inode *inode)
297 {
298 	return container_of(inode, struct hugetlbfs_inode_info, vfs_inode);
299 }
300 
301 extern const struct file_operations hugetlbfs_file_operations;
302 extern const struct vm_operations_struct hugetlb_vm_ops;
303 struct file *hugetlb_file_setup(const char *name, size_t size, vm_flags_t acct,
304 				struct user_struct **user, int creat_flags,
305 				int page_size_log);
306 
307 static inline bool is_file_hugepages(struct file *file)
308 {
309 	if (file->f_op == &hugetlbfs_file_operations)
310 		return true;
311 
312 	return is_file_shm_hugepages(file);
313 }
314 
315 
316 #else /* !CONFIG_HUGETLBFS */
317 
318 #define is_file_hugepages(file)			false
319 static inline struct file *
320 hugetlb_file_setup(const char *name, size_t size, vm_flags_t acctflag,
321 		struct user_struct **user, int creat_flags,
322 		int page_size_log)
323 {
324 	return ERR_PTR(-ENOSYS);
325 }
326 
327 #endif /* !CONFIG_HUGETLBFS */
328 
329 #ifdef HAVE_ARCH_HUGETLB_UNMAPPED_AREA
330 unsigned long hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
331 					unsigned long len, unsigned long pgoff,
332 					unsigned long flags);
333 #endif /* HAVE_ARCH_HUGETLB_UNMAPPED_AREA */
334 
335 #ifdef CONFIG_HUGETLB_PAGE
336 
337 #define HSTATE_NAME_LEN 32
338 /* Defines one hugetlb page size */
339 struct hstate {
340 	int next_nid_to_alloc;
341 	int next_nid_to_free;
342 	unsigned int order;
343 	unsigned long mask;
344 	unsigned long max_huge_pages;
345 	unsigned long nr_huge_pages;
346 	unsigned long free_huge_pages;
347 	unsigned long resv_huge_pages;
348 	unsigned long surplus_huge_pages;
349 	unsigned long nr_overcommit_huge_pages;
350 	struct list_head hugepage_activelist;
351 	struct list_head hugepage_freelists[MAX_NUMNODES];
352 	unsigned int nr_huge_pages_node[MAX_NUMNODES];
353 	unsigned int free_huge_pages_node[MAX_NUMNODES];
354 	unsigned int surplus_huge_pages_node[MAX_NUMNODES];
355 #ifdef CONFIG_CGROUP_HUGETLB
356 	/* cgroup control files */
357 	struct cftype cgroup_files[5];
358 #endif
359 	char name[HSTATE_NAME_LEN];
360 };
361 
362 struct huge_bootmem_page {
363 	struct list_head list;
364 	struct hstate *hstate;
365 };
366 
367 struct page *alloc_huge_page(struct vm_area_struct *vma,
368 				unsigned long addr, int avoid_reserve);
369 struct page *alloc_huge_page_node(struct hstate *h, int nid);
370 struct page *alloc_huge_page_nodemask(struct hstate *h, int preferred_nid,
371 				nodemask_t *nmask);
372 struct page *alloc_huge_page_vma(struct hstate *h, struct vm_area_struct *vma,
373 				unsigned long address);
374 struct page *alloc_migrate_huge_page(struct hstate *h, gfp_t gfp_mask,
375 				     int nid, nodemask_t *nmask);
376 int huge_add_to_page_cache(struct page *page, struct address_space *mapping,
377 			pgoff_t idx);
378 
379 /* arch callback */
380 int __init __alloc_bootmem_huge_page(struct hstate *h);
381 int __init alloc_bootmem_huge_page(struct hstate *h);
382 
383 void __init hugetlb_bad_size(void);
384 void __init hugetlb_add_hstate(unsigned order);
385 struct hstate *size_to_hstate(unsigned long size);
386 
387 #ifndef HUGE_MAX_HSTATE
388 #define HUGE_MAX_HSTATE 1
389 #endif
390 
391 extern struct hstate hstates[HUGE_MAX_HSTATE];
392 extern unsigned int default_hstate_idx;
393 
394 #define default_hstate (hstates[default_hstate_idx])
395 
396 static inline struct hstate *hstate_inode(struct inode *i)
397 {
398 	return HUGETLBFS_SB(i->i_sb)->hstate;
399 }
400 
401 static inline struct hstate *hstate_file(struct file *f)
402 {
403 	return hstate_inode(file_inode(f));
404 }
405 
406 static inline struct hstate *hstate_sizelog(int page_size_log)
407 {
408 	if (!page_size_log)
409 		return &default_hstate;
410 
411 	return size_to_hstate(1UL << page_size_log);
412 }
413 
414 static inline struct hstate *hstate_vma(struct vm_area_struct *vma)
415 {
416 	return hstate_file(vma->vm_file);
417 }
418 
419 static inline unsigned long huge_page_size(struct hstate *h)
420 {
421 	return (unsigned long)PAGE_SIZE << h->order;
422 }
423 
424 extern unsigned long vma_kernel_pagesize(struct vm_area_struct *vma);
425 
426 extern unsigned long vma_mmu_pagesize(struct vm_area_struct *vma);
427 
428 static inline unsigned long huge_page_mask(struct hstate *h)
429 {
430 	return h->mask;
431 }
432 
433 static inline unsigned int huge_page_order(struct hstate *h)
434 {
435 	return h->order;
436 }
437 
438 static inline unsigned huge_page_shift(struct hstate *h)
439 {
440 	return h->order + PAGE_SHIFT;
441 }
442 
443 static inline bool hstate_is_gigantic(struct hstate *h)
444 {
445 	return huge_page_order(h) >= MAX_ORDER;
446 }
447 
448 static inline unsigned int pages_per_huge_page(struct hstate *h)
449 {
450 	return 1 << h->order;
451 }
452 
453 static inline unsigned int blocks_per_huge_page(struct hstate *h)
454 {
455 	return huge_page_size(h) / 512;
456 }
457 
458 #include <asm/hugetlb.h>
459 
460 #ifndef arch_make_huge_pte
461 static inline pte_t arch_make_huge_pte(pte_t entry, struct vm_area_struct *vma,
462 				       struct page *page, int writable)
463 {
464 	return entry;
465 }
466 #endif
467 
468 static inline struct hstate *page_hstate(struct page *page)
469 {
470 	VM_BUG_ON_PAGE(!PageHuge(page), page);
471 	return size_to_hstate(PAGE_SIZE << compound_order(page));
472 }
473 
474 static inline unsigned hstate_index_to_shift(unsigned index)
475 {
476 	return hstates[index].order + PAGE_SHIFT;
477 }
478 
479 static inline int hstate_index(struct hstate *h)
480 {
481 	return h - hstates;
482 }
483 
484 pgoff_t __basepage_index(struct page *page);
485 
486 /* Return page->index in PAGE_SIZE units */
487 static inline pgoff_t basepage_index(struct page *page)
488 {
489 	if (!PageCompound(page))
490 		return page->index;
491 
492 	return __basepage_index(page);
493 }
494 
495 extern int dissolve_free_huge_page(struct page *page);
496 extern int dissolve_free_huge_pages(unsigned long start_pfn,
497 				    unsigned long end_pfn);
498 
499 #ifdef CONFIG_ARCH_ENABLE_HUGEPAGE_MIGRATION
500 #ifndef arch_hugetlb_migration_supported
501 static inline bool arch_hugetlb_migration_supported(struct hstate *h)
502 {
503 	if ((huge_page_shift(h) == PMD_SHIFT) ||
504 		(huge_page_shift(h) == PUD_SHIFT) ||
505 			(huge_page_shift(h) == PGDIR_SHIFT))
506 		return true;
507 	else
508 		return false;
509 }
510 #endif
511 #else
512 static inline bool arch_hugetlb_migration_supported(struct hstate *h)
513 {
514 	return false;
515 }
516 #endif
517 
518 static inline bool hugepage_migration_supported(struct hstate *h)
519 {
520 	return arch_hugetlb_migration_supported(h);
521 }
522 
523 /*
524  * Movability check is different as compared to migration check.
525  * It determines whether or not a huge page should be placed on
526  * movable zone or not. Movability of any huge page should be
527  * required only if huge page size is supported for migration.
528  * There wont be any reason for the huge page to be movable if
529  * it is not migratable to start with. Also the size of the huge
530  * page should be large enough to be placed under a movable zone
531  * and still feasible enough to be migratable. Just the presence
532  * in movable zone does not make the migration feasible.
533  *
534  * So even though large huge page sizes like the gigantic ones
535  * are migratable they should not be movable because its not
536  * feasible to migrate them from movable zone.
537  */
538 static inline bool hugepage_movable_supported(struct hstate *h)
539 {
540 	if (!hugepage_migration_supported(h))
541 		return false;
542 
543 	if (hstate_is_gigantic(h))
544 		return false;
545 	return true;
546 }
547 
548 static inline spinlock_t *huge_pte_lockptr(struct hstate *h,
549 					   struct mm_struct *mm, pte_t *pte)
550 {
551 	if (huge_page_size(h) == PMD_SIZE)
552 		return pmd_lockptr(mm, (pmd_t *) pte);
553 	VM_BUG_ON(huge_page_size(h) == PAGE_SIZE);
554 	return &mm->page_table_lock;
555 }
556 
557 #ifndef hugepages_supported
558 /*
559  * Some platform decide whether they support huge pages at boot
560  * time. Some of them, such as powerpc, set HPAGE_SHIFT to 0
561  * when there is no such support
562  */
563 #define hugepages_supported() (HPAGE_SHIFT != 0)
564 #endif
565 
566 void hugetlb_report_usage(struct seq_file *m, struct mm_struct *mm);
567 
568 static inline void hugetlb_count_add(long l, struct mm_struct *mm)
569 {
570 	atomic_long_add(l, &mm->hugetlb_usage);
571 }
572 
573 static inline void hugetlb_count_sub(long l, struct mm_struct *mm)
574 {
575 	atomic_long_sub(l, &mm->hugetlb_usage);
576 }
577 
578 #ifndef set_huge_swap_pte_at
579 static inline void set_huge_swap_pte_at(struct mm_struct *mm, unsigned long addr,
580 					pte_t *ptep, pte_t pte, unsigned long sz)
581 {
582 	set_huge_pte_at(mm, addr, ptep, pte);
583 }
584 #endif
585 
586 #ifndef huge_ptep_modify_prot_start
587 #define huge_ptep_modify_prot_start huge_ptep_modify_prot_start
588 static inline pte_t huge_ptep_modify_prot_start(struct vm_area_struct *vma,
589 						unsigned long addr, pte_t *ptep)
590 {
591 	return huge_ptep_get_and_clear(vma->vm_mm, addr, ptep);
592 }
593 #endif
594 
595 #ifndef huge_ptep_modify_prot_commit
596 #define huge_ptep_modify_prot_commit huge_ptep_modify_prot_commit
597 static inline void huge_ptep_modify_prot_commit(struct vm_area_struct *vma,
598 						unsigned long addr, pte_t *ptep,
599 						pte_t old_pte, pte_t pte)
600 {
601 	set_huge_pte_at(vma->vm_mm, addr, ptep, pte);
602 }
603 #endif
604 
605 #else	/* CONFIG_HUGETLB_PAGE */
606 struct hstate {};
607 #define alloc_huge_page(v, a, r) NULL
608 #define alloc_huge_page_node(h, nid) NULL
609 #define alloc_huge_page_nodemask(h, preferred_nid, nmask) NULL
610 #define alloc_huge_page_vma(h, vma, address) NULL
611 #define alloc_bootmem_huge_page(h) NULL
612 #define hstate_file(f) NULL
613 #define hstate_sizelog(s) NULL
614 #define hstate_vma(v) NULL
615 #define hstate_inode(i) NULL
616 #define page_hstate(page) NULL
617 #define huge_page_size(h) PAGE_SIZE
618 #define huge_page_mask(h) PAGE_MASK
619 #define vma_kernel_pagesize(v) PAGE_SIZE
620 #define vma_mmu_pagesize(v) PAGE_SIZE
621 #define huge_page_order(h) 0
622 #define huge_page_shift(h) PAGE_SHIFT
623 static inline bool hstate_is_gigantic(struct hstate *h)
624 {
625 	return false;
626 }
627 
628 static inline unsigned int pages_per_huge_page(struct hstate *h)
629 {
630 	return 1;
631 }
632 
633 static inline unsigned hstate_index_to_shift(unsigned index)
634 {
635 	return 0;
636 }
637 
638 static inline int hstate_index(struct hstate *h)
639 {
640 	return 0;
641 }
642 
643 static inline pgoff_t basepage_index(struct page *page)
644 {
645 	return page->index;
646 }
647 
648 static inline int dissolve_free_huge_page(struct page *page)
649 {
650 	return 0;
651 }
652 
653 static inline int dissolve_free_huge_pages(unsigned long start_pfn,
654 					   unsigned long end_pfn)
655 {
656 	return 0;
657 }
658 
659 static inline bool hugepage_migration_supported(struct hstate *h)
660 {
661 	return false;
662 }
663 
664 static inline bool hugepage_movable_supported(struct hstate *h)
665 {
666 	return false;
667 }
668 
669 static inline spinlock_t *huge_pte_lockptr(struct hstate *h,
670 					   struct mm_struct *mm, pte_t *pte)
671 {
672 	return &mm->page_table_lock;
673 }
674 
675 static inline void hugetlb_report_usage(struct seq_file *f, struct mm_struct *m)
676 {
677 }
678 
679 static inline void hugetlb_count_sub(long l, struct mm_struct *mm)
680 {
681 }
682 
683 static inline void set_huge_swap_pte_at(struct mm_struct *mm, unsigned long addr,
684 					pte_t *ptep, pte_t pte, unsigned long sz)
685 {
686 }
687 #endif	/* CONFIG_HUGETLB_PAGE */
688 
689 static inline spinlock_t *huge_pte_lock(struct hstate *h,
690 					struct mm_struct *mm, pte_t *pte)
691 {
692 	spinlock_t *ptl;
693 
694 	ptl = huge_pte_lockptr(h, mm, pte);
695 	spin_lock(ptl);
696 	return ptl;
697 }
698 
699 #endif /* _LINUX_HUGETLB_H */
700