xref: /linux-6.15/include/linux/hugetlb.h (revision 82d00a93)
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 typedef struct { unsigned long pd; } hugepd_t;
20 #define is_hugepd(hugepd) (0)
21 #define __hugepd(x) ((hugepd_t) { (x) })
22 #endif
23 
24 #ifdef CONFIG_HUGETLB_PAGE
25 
26 #include <linux/mempolicy.h>
27 #include <linux/shm.h>
28 #include <asm/tlbflush.h>
29 
30 struct hugepage_subpool {
31 	spinlock_t lock;
32 	long count;
33 	long max_hpages;	/* Maximum huge pages or -1 if no maximum. */
34 	long used_hpages;	/* Used count against maximum, includes */
35 				/* both alloced and reserved pages. */
36 	struct hstate *hstate;
37 	long min_hpages;	/* Minimum huge pages or -1 if no minimum. */
38 	long rsv_hpages;	/* Pages reserved against global pool to */
39 				/* sasitfy minimum size. */
40 };
41 
42 struct resv_map {
43 	struct kref refs;
44 	spinlock_t lock;
45 	struct list_head regions;
46 	long adds_in_progress;
47 	struct list_head region_cache;
48 	long region_cache_count;
49 #ifdef CONFIG_CGROUP_HUGETLB
50 	/*
51 	 * On private mappings, the counter to uncharge reservations is stored
52 	 * here. If these fields are 0, then either the mapping is shared, or
53 	 * cgroup accounting is disabled for this resv_map.
54 	 */
55 	struct page_counter *reservation_counter;
56 	unsigned long pages_per_hpage;
57 	struct cgroup_subsys_state *css;
58 #endif
59 };
60 
61 /*
62  * Region tracking -- allows tracking of reservations and instantiated pages
63  *                    across the pages in a mapping.
64  *
65  * The region data structures are embedded into a resv_map and protected
66  * by a resv_map's lock.  The set of regions within the resv_map represent
67  * reservations for huge pages, or huge pages that have already been
68  * instantiated within the map.  The from and to elements are huge page
69  * indicies into the associated mapping.  from indicates the starting index
70  * of the region.  to represents the first index past the end of  the region.
71  *
72  * For example, a file region structure with from == 0 and to == 4 represents
73  * four huge pages in a mapping.  It is important to note that the to element
74  * represents the first element past the end of the region. This is used in
75  * arithmetic as 4(to) - 0(from) = 4 huge pages in the region.
76  *
77  * Interval notation of the form [from, to) will be used to indicate that
78  * the endpoint from is inclusive and to is exclusive.
79  */
80 struct file_region {
81 	struct list_head link;
82 	long from;
83 	long to;
84 #ifdef CONFIG_CGROUP_HUGETLB
85 	/*
86 	 * On shared mappings, each reserved region appears as a struct
87 	 * file_region in resv_map. These fields hold the info needed to
88 	 * uncharge each reservation.
89 	 */
90 	struct page_counter *reservation_counter;
91 	struct cgroup_subsys_state *css;
92 #endif
93 };
94 
95 extern struct resv_map *resv_map_alloc(void);
96 void resv_map_release(struct kref *ref);
97 
98 extern spinlock_t hugetlb_lock;
99 extern int hugetlb_max_hstate __read_mostly;
100 #define for_each_hstate(h) \
101 	for ((h) = hstates; (h) < &hstates[hugetlb_max_hstate]; (h)++)
102 
103 struct hugepage_subpool *hugepage_new_subpool(struct hstate *h, long max_hpages,
104 						long min_hpages);
105 void hugepage_put_subpool(struct hugepage_subpool *spool);
106 
107 void reset_vma_resv_huge_pages(struct vm_area_struct *vma);
108 int hugetlb_sysctl_handler(struct ctl_table *, int, void __user *, size_t *, loff_t *);
109 int hugetlb_overcommit_handler(struct ctl_table *, int, void __user *, size_t *, loff_t *);
110 int hugetlb_treat_movable_handler(struct ctl_table *, int, void __user *, size_t *, loff_t *);
111 
112 #ifdef CONFIG_NUMA
113 int hugetlb_mempolicy_sysctl_handler(struct ctl_table *, int,
114 					void __user *, size_t *, loff_t *);
115 #endif
116 
117 int copy_hugetlb_page_range(struct mm_struct *, struct mm_struct *, struct vm_area_struct *);
118 long follow_hugetlb_page(struct mm_struct *, struct vm_area_struct *,
119 			 struct page **, struct vm_area_struct **,
120 			 unsigned long *, unsigned long *, long, unsigned int,
121 			 int *);
122 void unmap_hugepage_range(struct vm_area_struct *,
123 			  unsigned long, unsigned long, struct page *);
124 void __unmap_hugepage_range_final(struct mmu_gather *tlb,
125 			  struct vm_area_struct *vma,
126 			  unsigned long start, unsigned long end,
127 			  struct page *ref_page);
128 void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct *vma,
129 				unsigned long start, unsigned long end,
130 				struct page *ref_page);
131 void hugetlb_report_meminfo(struct seq_file *);
132 int hugetlb_report_node_meminfo(int, char *);
133 void hugetlb_show_meminfo(void);
134 unsigned long hugetlb_total_pages(void);
135 vm_fault_t hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
136 			unsigned long address, unsigned int flags);
137 int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm, pte_t *dst_pte,
138 				struct vm_area_struct *dst_vma,
139 				unsigned long dst_addr,
140 				unsigned long src_addr,
141 				struct page **pagep);
142 int hugetlb_reserve_pages(struct inode *inode, long from, long to,
143 						struct vm_area_struct *vma,
144 						vm_flags_t vm_flags);
145 long hugetlb_unreserve_pages(struct inode *inode, long start, long end,
146 						long freed);
147 bool isolate_huge_page(struct page *page, struct list_head *list);
148 void putback_active_hugepage(struct page *page);
149 void move_hugetlb_state(struct page *oldpage, struct page *newpage, int reason);
150 void free_huge_page(struct page *page);
151 void hugetlb_fix_reserve_counts(struct inode *inode);
152 extern struct mutex *hugetlb_fault_mutex_table;
153 u32 hugetlb_fault_mutex_hash(struct address_space *mapping, pgoff_t idx);
154 
155 pte_t *huge_pmd_share(struct mm_struct *mm, unsigned long addr, pud_t *pud);
156 
157 struct address_space *hugetlb_page_mapping_lock_write(struct page *hpage);
158 
159 extern int sysctl_hugetlb_shm_group;
160 extern struct list_head huge_boot_pages;
161 
162 /* arch callbacks */
163 
164 pte_t *huge_pte_alloc(struct mm_struct *mm,
165 			unsigned long addr, unsigned long sz);
166 pte_t *huge_pte_offset(struct mm_struct *mm,
167 		       unsigned long addr, unsigned long sz);
168 int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep);
169 void adjust_range_if_pmd_sharing_possible(struct vm_area_struct *vma,
170 				unsigned long *start, unsigned long *end);
171 struct page *follow_huge_addr(struct mm_struct *mm, unsigned long address,
172 			      int write);
173 struct page *follow_huge_pd(struct vm_area_struct *vma,
174 			    unsigned long address, hugepd_t hpd,
175 			    int flags, int pdshift);
176 struct page *follow_huge_pmd(struct mm_struct *mm, unsigned long address,
177 				pmd_t *pmd, int flags);
178 struct page *follow_huge_pud(struct mm_struct *mm, unsigned long address,
179 				pud_t *pud, int flags);
180 struct page *follow_huge_pgd(struct mm_struct *mm, unsigned long address,
181 			     pgd_t *pgd, int flags);
182 
183 int pmd_huge(pmd_t pmd);
184 int pud_huge(pud_t pud);
185 unsigned long hugetlb_change_protection(struct vm_area_struct *vma,
186 		unsigned long address, unsigned long end, pgprot_t newprot);
187 
188 bool is_hugetlb_entry_migration(pte_t pte);
189 
190 #else /* !CONFIG_HUGETLB_PAGE */
191 
192 static inline void reset_vma_resv_huge_pages(struct vm_area_struct *vma)
193 {
194 }
195 
196 static inline unsigned long hugetlb_total_pages(void)
197 {
198 	return 0;
199 }
200 
201 static inline struct address_space *hugetlb_page_mapping_lock_write(
202 							struct page *hpage)
203 {
204 	return NULL;
205 }
206 
207 static inline int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr,
208 					pte_t *ptep)
209 {
210 	return 0;
211 }
212 
213 static inline void adjust_range_if_pmd_sharing_possible(
214 				struct vm_area_struct *vma,
215 				unsigned long *start, unsigned long *end)
216 {
217 }
218 
219 static inline long follow_hugetlb_page(struct mm_struct *mm,
220 			struct vm_area_struct *vma, struct page **pages,
221 			struct vm_area_struct **vmas, unsigned long *position,
222 			unsigned long *nr_pages, long i, unsigned int flags,
223 			int *nonblocking)
224 {
225 	BUG();
226 	return 0;
227 }
228 
229 static inline struct page *follow_huge_addr(struct mm_struct *mm,
230 					unsigned long address, int write)
231 {
232 	return ERR_PTR(-EINVAL);
233 }
234 
235 static inline int copy_hugetlb_page_range(struct mm_struct *dst,
236 			struct mm_struct *src, struct vm_area_struct *vma)
237 {
238 	BUG();
239 	return 0;
240 }
241 
242 static inline void hugetlb_report_meminfo(struct seq_file *m)
243 {
244 }
245 
246 static inline int hugetlb_report_node_meminfo(int nid, char *buf)
247 {
248 	return 0;
249 }
250 
251 static inline void hugetlb_show_meminfo(void)
252 {
253 }
254 
255 static inline struct page *follow_huge_pd(struct vm_area_struct *vma,
256 				unsigned long address, hugepd_t hpd, int flags,
257 				int pdshift)
258 {
259 	return NULL;
260 }
261 
262 static inline struct page *follow_huge_pmd(struct mm_struct *mm,
263 				unsigned long address, pmd_t *pmd, int flags)
264 {
265 	return NULL;
266 }
267 
268 static inline struct page *follow_huge_pud(struct mm_struct *mm,
269 				unsigned long address, pud_t *pud, int flags)
270 {
271 	return NULL;
272 }
273 
274 static inline struct page *follow_huge_pgd(struct mm_struct *mm,
275 				unsigned long address, pgd_t *pgd, int flags)
276 {
277 	return NULL;
278 }
279 
280 static inline int prepare_hugepage_range(struct file *file,
281 				unsigned long addr, unsigned long len)
282 {
283 	return -EINVAL;
284 }
285 
286 static inline int pmd_huge(pmd_t pmd)
287 {
288 	return 0;
289 }
290 
291 static inline int pud_huge(pud_t pud)
292 {
293 	return 0;
294 }
295 
296 static inline int is_hugepage_only_range(struct mm_struct *mm,
297 					unsigned long addr, unsigned long len)
298 {
299 	return 0;
300 }
301 
302 static inline void hugetlb_free_pgd_range(struct mmu_gather *tlb,
303 				unsigned long addr, unsigned long end,
304 				unsigned long floor, unsigned long ceiling)
305 {
306 	BUG();
307 }
308 
309 static inline int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm,
310 						pte_t *dst_pte,
311 						struct vm_area_struct *dst_vma,
312 						unsigned long dst_addr,
313 						unsigned long src_addr,
314 						struct page **pagep)
315 {
316 	BUG();
317 	return 0;
318 }
319 
320 static inline pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr,
321 					unsigned long sz)
322 {
323 	return NULL;
324 }
325 
326 static inline bool isolate_huge_page(struct page *page, struct list_head *list)
327 {
328 	return false;
329 }
330 
331 static inline void putback_active_hugepage(struct page *page)
332 {
333 }
334 
335 static inline void move_hugetlb_state(struct page *oldpage,
336 					struct page *newpage, int reason)
337 {
338 }
339 
340 static inline unsigned long hugetlb_change_protection(
341 			struct vm_area_struct *vma, unsigned long address,
342 			unsigned long end, pgprot_t newprot)
343 {
344 	return 0;
345 }
346 
347 static inline void __unmap_hugepage_range_final(struct mmu_gather *tlb,
348 			struct vm_area_struct *vma, unsigned long start,
349 			unsigned long end, struct page *ref_page)
350 {
351 	BUG();
352 }
353 
354 static inline void __unmap_hugepage_range(struct mmu_gather *tlb,
355 			struct vm_area_struct *vma, unsigned long start,
356 			unsigned long end, struct page *ref_page)
357 {
358 	BUG();
359 }
360 
361 static inline vm_fault_t hugetlb_fault(struct mm_struct *mm,
362 			struct vm_area_struct *vma, unsigned long address,
363 			unsigned int flags)
364 {
365 	BUG();
366 	return 0;
367 }
368 
369 #endif /* !CONFIG_HUGETLB_PAGE */
370 /*
371  * hugepages at page global directory. If arch support
372  * hugepages at pgd level, they need to define this.
373  */
374 #ifndef pgd_huge
375 #define pgd_huge(x)	0
376 #endif
377 #ifndef p4d_huge
378 #define p4d_huge(x)	0
379 #endif
380 
381 #ifndef pgd_write
382 static inline int pgd_write(pgd_t pgd)
383 {
384 	BUG();
385 	return 0;
386 }
387 #endif
388 
389 #define HUGETLB_ANON_FILE "anon_hugepage"
390 
391 enum {
392 	/*
393 	 * The file will be used as an shm file so shmfs accounting rules
394 	 * apply
395 	 */
396 	HUGETLB_SHMFS_INODE     = 1,
397 	/*
398 	 * The file is being created on the internal vfs mount and shmfs
399 	 * accounting rules do not apply
400 	 */
401 	HUGETLB_ANONHUGE_INODE  = 2,
402 };
403 
404 #ifdef CONFIG_HUGETLBFS
405 struct hugetlbfs_sb_info {
406 	long	max_inodes;   /* inodes allowed */
407 	long	free_inodes;  /* inodes free */
408 	spinlock_t	stat_lock;
409 	struct hstate *hstate;
410 	struct hugepage_subpool *spool;
411 	kuid_t	uid;
412 	kgid_t	gid;
413 	umode_t mode;
414 };
415 
416 static inline struct hugetlbfs_sb_info *HUGETLBFS_SB(struct super_block *sb)
417 {
418 	return sb->s_fs_info;
419 }
420 
421 struct hugetlbfs_inode_info {
422 	struct shared_policy policy;
423 	struct inode vfs_inode;
424 	unsigned int seals;
425 };
426 
427 static inline struct hugetlbfs_inode_info *HUGETLBFS_I(struct inode *inode)
428 {
429 	return container_of(inode, struct hugetlbfs_inode_info, vfs_inode);
430 }
431 
432 extern const struct file_operations hugetlbfs_file_operations;
433 extern const struct vm_operations_struct hugetlb_vm_ops;
434 struct file *hugetlb_file_setup(const char *name, size_t size, vm_flags_t acct,
435 				struct user_struct **user, int creat_flags,
436 				int page_size_log);
437 
438 static inline bool is_file_hugepages(struct file *file)
439 {
440 	if (file->f_op == &hugetlbfs_file_operations)
441 		return true;
442 
443 	return is_file_shm_hugepages(file);
444 }
445 
446 static inline struct hstate *hstate_inode(struct inode *i)
447 {
448 	return HUGETLBFS_SB(i->i_sb)->hstate;
449 }
450 #else /* !CONFIG_HUGETLBFS */
451 
452 #define is_file_hugepages(file)			false
453 static inline struct file *
454 hugetlb_file_setup(const char *name, size_t size, vm_flags_t acctflag,
455 		struct user_struct **user, int creat_flags,
456 		int page_size_log)
457 {
458 	return ERR_PTR(-ENOSYS);
459 }
460 
461 static inline struct hstate *hstate_inode(struct inode *i)
462 {
463 	return NULL;
464 }
465 #endif /* !CONFIG_HUGETLBFS */
466 
467 #ifdef HAVE_ARCH_HUGETLB_UNMAPPED_AREA
468 unsigned long hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
469 					unsigned long len, unsigned long pgoff,
470 					unsigned long flags);
471 #endif /* HAVE_ARCH_HUGETLB_UNMAPPED_AREA */
472 
473 #ifdef CONFIG_HUGETLB_PAGE
474 
475 #define HSTATE_NAME_LEN 32
476 /* Defines one hugetlb page size */
477 struct hstate {
478 	int next_nid_to_alloc;
479 	int next_nid_to_free;
480 	unsigned int order;
481 	unsigned long mask;
482 	unsigned long max_huge_pages;
483 	unsigned long nr_huge_pages;
484 	unsigned long free_huge_pages;
485 	unsigned long resv_huge_pages;
486 	unsigned long surplus_huge_pages;
487 	unsigned long nr_overcommit_huge_pages;
488 	struct list_head hugepage_activelist;
489 	struct list_head hugepage_freelists[MAX_NUMNODES];
490 	unsigned int nr_huge_pages_node[MAX_NUMNODES];
491 	unsigned int free_huge_pages_node[MAX_NUMNODES];
492 	unsigned int surplus_huge_pages_node[MAX_NUMNODES];
493 #ifdef CONFIG_CGROUP_HUGETLB
494 	/* cgroup control files */
495 	struct cftype cgroup_files_dfl[7];
496 	struct cftype cgroup_files_legacy[9];
497 #endif
498 	char name[HSTATE_NAME_LEN];
499 };
500 
501 struct huge_bootmem_page {
502 	struct list_head list;
503 	struct hstate *hstate;
504 };
505 
506 struct page *alloc_huge_page(struct vm_area_struct *vma,
507 				unsigned long addr, int avoid_reserve);
508 struct page *alloc_huge_page_node(struct hstate *h, int nid);
509 struct page *alloc_huge_page_nodemask(struct hstate *h, int preferred_nid,
510 				nodemask_t *nmask);
511 struct page *alloc_huge_page_vma(struct hstate *h, struct vm_area_struct *vma,
512 				unsigned long address);
513 struct page *alloc_migrate_huge_page(struct hstate *h, gfp_t gfp_mask,
514 				     int nid, nodemask_t *nmask);
515 int huge_add_to_page_cache(struct page *page, struct address_space *mapping,
516 			pgoff_t idx);
517 
518 /* arch callback */
519 int __init __alloc_bootmem_huge_page(struct hstate *h);
520 int __init alloc_bootmem_huge_page(struct hstate *h);
521 
522 void __init hugetlb_bad_size(void);
523 void __init hugetlb_add_hstate(unsigned order);
524 struct hstate *size_to_hstate(unsigned long size);
525 
526 #ifndef HUGE_MAX_HSTATE
527 #define HUGE_MAX_HSTATE 1
528 #endif
529 
530 extern struct hstate hstates[HUGE_MAX_HSTATE];
531 extern unsigned int default_hstate_idx;
532 
533 #define default_hstate (hstates[default_hstate_idx])
534 
535 static inline struct hstate *hstate_file(struct file *f)
536 {
537 	return hstate_inode(file_inode(f));
538 }
539 
540 static inline struct hstate *hstate_sizelog(int page_size_log)
541 {
542 	if (!page_size_log)
543 		return &default_hstate;
544 
545 	return size_to_hstate(1UL << page_size_log);
546 }
547 
548 static inline struct hstate *hstate_vma(struct vm_area_struct *vma)
549 {
550 	return hstate_file(vma->vm_file);
551 }
552 
553 static inline unsigned long huge_page_size(struct hstate *h)
554 {
555 	return (unsigned long)PAGE_SIZE << h->order;
556 }
557 
558 extern unsigned long vma_kernel_pagesize(struct vm_area_struct *vma);
559 
560 extern unsigned long vma_mmu_pagesize(struct vm_area_struct *vma);
561 
562 static inline unsigned long huge_page_mask(struct hstate *h)
563 {
564 	return h->mask;
565 }
566 
567 static inline unsigned int huge_page_order(struct hstate *h)
568 {
569 	return h->order;
570 }
571 
572 static inline unsigned huge_page_shift(struct hstate *h)
573 {
574 	return h->order + PAGE_SHIFT;
575 }
576 
577 static inline bool hstate_is_gigantic(struct hstate *h)
578 {
579 	return huge_page_order(h) >= MAX_ORDER;
580 }
581 
582 static inline unsigned int pages_per_huge_page(struct hstate *h)
583 {
584 	return 1 << h->order;
585 }
586 
587 static inline unsigned int blocks_per_huge_page(struct hstate *h)
588 {
589 	return huge_page_size(h) / 512;
590 }
591 
592 #include <asm/hugetlb.h>
593 
594 #ifndef arch_make_huge_pte
595 static inline pte_t arch_make_huge_pte(pte_t entry, struct vm_area_struct *vma,
596 				       struct page *page, int writable)
597 {
598 	return entry;
599 }
600 #endif
601 
602 static inline struct hstate *page_hstate(struct page *page)
603 {
604 	VM_BUG_ON_PAGE(!PageHuge(page), page);
605 	return size_to_hstate(page_size(page));
606 }
607 
608 static inline unsigned hstate_index_to_shift(unsigned index)
609 {
610 	return hstates[index].order + PAGE_SHIFT;
611 }
612 
613 static inline int hstate_index(struct hstate *h)
614 {
615 	return h - hstates;
616 }
617 
618 pgoff_t __basepage_index(struct page *page);
619 
620 /* Return page->index in PAGE_SIZE units */
621 static inline pgoff_t basepage_index(struct page *page)
622 {
623 	if (!PageCompound(page))
624 		return page->index;
625 
626 	return __basepage_index(page);
627 }
628 
629 extern int dissolve_free_huge_page(struct page *page);
630 extern int dissolve_free_huge_pages(unsigned long start_pfn,
631 				    unsigned long end_pfn);
632 
633 #ifdef CONFIG_ARCH_ENABLE_HUGEPAGE_MIGRATION
634 #ifndef arch_hugetlb_migration_supported
635 static inline bool arch_hugetlb_migration_supported(struct hstate *h)
636 {
637 	if ((huge_page_shift(h) == PMD_SHIFT) ||
638 		(huge_page_shift(h) == PUD_SHIFT) ||
639 			(huge_page_shift(h) == PGDIR_SHIFT))
640 		return true;
641 	else
642 		return false;
643 }
644 #endif
645 #else
646 static inline bool arch_hugetlb_migration_supported(struct hstate *h)
647 {
648 	return false;
649 }
650 #endif
651 
652 static inline bool hugepage_migration_supported(struct hstate *h)
653 {
654 	return arch_hugetlb_migration_supported(h);
655 }
656 
657 /*
658  * Movability check is different as compared to migration check.
659  * It determines whether or not a huge page should be placed on
660  * movable zone or not. Movability of any huge page should be
661  * required only if huge page size is supported for migration.
662  * There wont be any reason for the huge page to be movable if
663  * it is not migratable to start with. Also the size of the huge
664  * page should be large enough to be placed under a movable zone
665  * and still feasible enough to be migratable. Just the presence
666  * in movable zone does not make the migration feasible.
667  *
668  * So even though large huge page sizes like the gigantic ones
669  * are migratable they should not be movable because its not
670  * feasible to migrate them from movable zone.
671  */
672 static inline bool hugepage_movable_supported(struct hstate *h)
673 {
674 	if (!hugepage_migration_supported(h))
675 		return false;
676 
677 	if (hstate_is_gigantic(h))
678 		return false;
679 	return true;
680 }
681 
682 static inline spinlock_t *huge_pte_lockptr(struct hstate *h,
683 					   struct mm_struct *mm, pte_t *pte)
684 {
685 	if (huge_page_size(h) == PMD_SIZE)
686 		return pmd_lockptr(mm, (pmd_t *) pte);
687 	VM_BUG_ON(huge_page_size(h) == PAGE_SIZE);
688 	return &mm->page_table_lock;
689 }
690 
691 #ifndef hugepages_supported
692 /*
693  * Some platform decide whether they support huge pages at boot
694  * time. Some of them, such as powerpc, set HPAGE_SHIFT to 0
695  * when there is no such support
696  */
697 #define hugepages_supported() (HPAGE_SHIFT != 0)
698 #endif
699 
700 void hugetlb_report_usage(struct seq_file *m, struct mm_struct *mm);
701 
702 static inline void hugetlb_count_add(long l, struct mm_struct *mm)
703 {
704 	atomic_long_add(l, &mm->hugetlb_usage);
705 }
706 
707 static inline void hugetlb_count_sub(long l, struct mm_struct *mm)
708 {
709 	atomic_long_sub(l, &mm->hugetlb_usage);
710 }
711 
712 #ifndef set_huge_swap_pte_at
713 static inline void set_huge_swap_pte_at(struct mm_struct *mm, unsigned long addr,
714 					pte_t *ptep, pte_t pte, unsigned long sz)
715 {
716 	set_huge_pte_at(mm, addr, ptep, pte);
717 }
718 #endif
719 
720 #ifndef huge_ptep_modify_prot_start
721 #define huge_ptep_modify_prot_start huge_ptep_modify_prot_start
722 static inline pte_t huge_ptep_modify_prot_start(struct vm_area_struct *vma,
723 						unsigned long addr, pte_t *ptep)
724 {
725 	return huge_ptep_get_and_clear(vma->vm_mm, addr, ptep);
726 }
727 #endif
728 
729 #ifndef huge_ptep_modify_prot_commit
730 #define huge_ptep_modify_prot_commit huge_ptep_modify_prot_commit
731 static inline void huge_ptep_modify_prot_commit(struct vm_area_struct *vma,
732 						unsigned long addr, pte_t *ptep,
733 						pte_t old_pte, pte_t pte)
734 {
735 	set_huge_pte_at(vma->vm_mm, addr, ptep, pte);
736 }
737 #endif
738 
739 #else	/* CONFIG_HUGETLB_PAGE */
740 struct hstate {};
741 
742 static inline struct page *alloc_huge_page(struct vm_area_struct *vma,
743 					   unsigned long addr,
744 					   int avoid_reserve)
745 {
746 	return NULL;
747 }
748 
749 static inline struct page *alloc_huge_page_node(struct hstate *h, int nid)
750 {
751 	return NULL;
752 }
753 
754 static inline struct page *
755 alloc_huge_page_nodemask(struct hstate *h, int preferred_nid, nodemask_t *nmask)
756 {
757 	return NULL;
758 }
759 
760 static inline struct page *alloc_huge_page_vma(struct hstate *h,
761 					       struct vm_area_struct *vma,
762 					       unsigned long address)
763 {
764 	return NULL;
765 }
766 
767 static inline int __alloc_bootmem_huge_page(struct hstate *h)
768 {
769 	return 0;
770 }
771 
772 static inline struct hstate *hstate_file(struct file *f)
773 {
774 	return NULL;
775 }
776 
777 static inline struct hstate *hstate_sizelog(int page_size_log)
778 {
779 	return NULL;
780 }
781 
782 static inline struct hstate *hstate_vma(struct vm_area_struct *vma)
783 {
784 	return NULL;
785 }
786 
787 static inline struct hstate *page_hstate(struct page *page)
788 {
789 	return NULL;
790 }
791 
792 static inline unsigned long huge_page_size(struct hstate *h)
793 {
794 	return PAGE_SIZE;
795 }
796 
797 static inline unsigned long huge_page_mask(struct hstate *h)
798 {
799 	return PAGE_MASK;
800 }
801 
802 static inline unsigned long vma_kernel_pagesize(struct vm_area_struct *vma)
803 {
804 	return PAGE_SIZE;
805 }
806 
807 static inline unsigned long vma_mmu_pagesize(struct vm_area_struct *vma)
808 {
809 	return PAGE_SIZE;
810 }
811 
812 static inline unsigned int huge_page_order(struct hstate *h)
813 {
814 	return 0;
815 }
816 
817 static inline unsigned int huge_page_shift(struct hstate *h)
818 {
819 	return PAGE_SHIFT;
820 }
821 
822 static inline bool hstate_is_gigantic(struct hstate *h)
823 {
824 	return false;
825 }
826 
827 static inline unsigned int pages_per_huge_page(struct hstate *h)
828 {
829 	return 1;
830 }
831 
832 static inline unsigned hstate_index_to_shift(unsigned index)
833 {
834 	return 0;
835 }
836 
837 static inline int hstate_index(struct hstate *h)
838 {
839 	return 0;
840 }
841 
842 static inline pgoff_t basepage_index(struct page *page)
843 {
844 	return page->index;
845 }
846 
847 static inline int dissolve_free_huge_page(struct page *page)
848 {
849 	return 0;
850 }
851 
852 static inline int dissolve_free_huge_pages(unsigned long start_pfn,
853 					   unsigned long end_pfn)
854 {
855 	return 0;
856 }
857 
858 static inline bool hugepage_migration_supported(struct hstate *h)
859 {
860 	return false;
861 }
862 
863 static inline bool hugepage_movable_supported(struct hstate *h)
864 {
865 	return false;
866 }
867 
868 static inline spinlock_t *huge_pte_lockptr(struct hstate *h,
869 					   struct mm_struct *mm, pte_t *pte)
870 {
871 	return &mm->page_table_lock;
872 }
873 
874 static inline void hugetlb_report_usage(struct seq_file *f, struct mm_struct *m)
875 {
876 }
877 
878 static inline void hugetlb_count_sub(long l, struct mm_struct *mm)
879 {
880 }
881 
882 static inline void set_huge_swap_pte_at(struct mm_struct *mm, unsigned long addr,
883 					pte_t *ptep, pte_t pte, unsigned long sz)
884 {
885 }
886 #endif	/* CONFIG_HUGETLB_PAGE */
887 
888 static inline spinlock_t *huge_pte_lock(struct hstate *h,
889 					struct mm_struct *mm, pte_t *pte)
890 {
891 	spinlock_t *ptl;
892 
893 	ptl = huge_pte_lockptr(h, mm, pte);
894 	spin_lock(ptl);
895 	return ptl;
896 }
897 
898 #if defined(CONFIG_HUGETLB_PAGE) && defined(CONFIG_CMA)
899 extern void __init hugetlb_cma_reserve(int order);
900 extern void __init hugetlb_cma_check(void);
901 #else
902 static inline __init void hugetlb_cma_reserve(int order)
903 {
904 }
905 static inline __init void hugetlb_cma_check(void)
906 {
907 }
908 #endif
909 
910 #endif /* _LINUX_HUGETLB_H */
911