xref: /linux-6.15/include/linux/hugetlb.h (revision bb79974c)
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 <linux/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 *, size_t *, loff_t *);
109 int hugetlb_overcommit_handler(struct ctl_table *, int, void *, size_t *,
110 		loff_t *);
111 int hugetlb_treat_movable_handler(struct ctl_table *, int, void *, size_t *,
112 		loff_t *);
113 int hugetlb_mempolicy_sysctl_handler(struct ctl_table *, int, void *, size_t *,
114 		loff_t *);
115 
116 int copy_hugetlb_page_range(struct mm_struct *, struct mm_struct *, struct vm_area_struct *);
117 long follow_hugetlb_page(struct mm_struct *, struct vm_area_struct *,
118 			 struct page **, struct vm_area_struct **,
119 			 unsigned long *, unsigned long *, long, unsigned int,
120 			 int *);
121 void unmap_hugepage_range(struct vm_area_struct *,
122 			  unsigned long, unsigned long, struct page *);
123 void __unmap_hugepage_range_final(struct mmu_gather *tlb,
124 			  struct vm_area_struct *vma,
125 			  unsigned long start, unsigned long end,
126 			  struct page *ref_page);
127 void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct *vma,
128 				unsigned long start, unsigned long end,
129 				struct page *ref_page);
130 void hugetlb_report_meminfo(struct seq_file *);
131 int hugetlb_report_node_meminfo(int, char *);
132 void hugetlb_show_meminfo(void);
133 unsigned long hugetlb_total_pages(void);
134 vm_fault_t hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
135 			unsigned long address, unsigned int flags);
136 int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm, pte_t *dst_pte,
137 				struct vm_area_struct *dst_vma,
138 				unsigned long dst_addr,
139 				unsigned long src_addr,
140 				struct page **pagep);
141 int hugetlb_reserve_pages(struct inode *inode, long from, long to,
142 						struct vm_area_struct *vma,
143 						vm_flags_t vm_flags);
144 long hugetlb_unreserve_pages(struct inode *inode, long start, long end,
145 						long freed);
146 bool isolate_huge_page(struct page *page, struct list_head *list);
147 void putback_active_hugepage(struct page *page);
148 void move_hugetlb_state(struct page *oldpage, struct page *newpage, int reason);
149 void free_huge_page(struct page *page);
150 void hugetlb_fix_reserve_counts(struct inode *inode);
151 extern struct mutex *hugetlb_fault_mutex_table;
152 u32 hugetlb_fault_mutex_hash(struct address_space *mapping, pgoff_t idx);
153 
154 pte_t *huge_pmd_share(struct mm_struct *mm, unsigned long addr, pud_t *pud);
155 
156 struct address_space *hugetlb_page_mapping_lock_write(struct page *hpage);
157 
158 extern int sysctl_hugetlb_shm_group;
159 extern struct list_head huge_boot_pages;
160 
161 /* arch callbacks */
162 
163 pte_t *huge_pte_alloc(struct mm_struct *mm,
164 			unsigned long addr, unsigned long sz);
165 pte_t *huge_pte_offset(struct mm_struct *mm,
166 		       unsigned long addr, unsigned long sz);
167 int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep);
168 void adjust_range_if_pmd_sharing_possible(struct vm_area_struct *vma,
169 				unsigned long *start, unsigned long *end);
170 struct page *follow_huge_addr(struct mm_struct *mm, unsigned long address,
171 			      int write);
172 struct page *follow_huge_pd(struct vm_area_struct *vma,
173 			    unsigned long address, hugepd_t hpd,
174 			    int flags, int pdshift);
175 struct page *follow_huge_pmd(struct mm_struct *mm, unsigned long address,
176 				pmd_t *pmd, int flags);
177 struct page *follow_huge_pud(struct mm_struct *mm, unsigned long address,
178 				pud_t *pud, int flags);
179 struct page *follow_huge_pgd(struct mm_struct *mm, unsigned long address,
180 			     pgd_t *pgd, int flags);
181 
182 int pmd_huge(pmd_t pmd);
183 int pud_huge(pud_t pud);
184 unsigned long hugetlb_change_protection(struct vm_area_struct *vma,
185 		unsigned long address, unsigned long end, pgprot_t newprot);
186 
187 bool is_hugetlb_entry_migration(pte_t pte);
188 
189 #else /* !CONFIG_HUGETLB_PAGE */
190 
191 static inline void reset_vma_resv_huge_pages(struct vm_area_struct *vma)
192 {
193 }
194 
195 static inline unsigned long hugetlb_total_pages(void)
196 {
197 	return 0;
198 }
199 
200 static inline struct address_space *hugetlb_page_mapping_lock_write(
201 							struct page *hpage)
202 {
203 	return NULL;
204 }
205 
206 static inline int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr,
207 					pte_t *ptep)
208 {
209 	return 0;
210 }
211 
212 static inline void adjust_range_if_pmd_sharing_possible(
213 				struct vm_area_struct *vma,
214 				unsigned long *start, unsigned long *end)
215 {
216 }
217 
218 static inline long follow_hugetlb_page(struct mm_struct *mm,
219 			struct vm_area_struct *vma, struct page **pages,
220 			struct vm_area_struct **vmas, unsigned long *position,
221 			unsigned long *nr_pages, long i, unsigned int flags,
222 			int *nonblocking)
223 {
224 	BUG();
225 	return 0;
226 }
227 
228 static inline struct page *follow_huge_addr(struct mm_struct *mm,
229 					unsigned long address, int write)
230 {
231 	return ERR_PTR(-EINVAL);
232 }
233 
234 static inline int copy_hugetlb_page_range(struct mm_struct *dst,
235 			struct mm_struct *src, struct vm_area_struct *vma)
236 {
237 	BUG();
238 	return 0;
239 }
240 
241 static inline void hugetlb_report_meminfo(struct seq_file *m)
242 {
243 }
244 
245 static inline int hugetlb_report_node_meminfo(int nid, char *buf)
246 {
247 	return 0;
248 }
249 
250 static inline void hugetlb_show_meminfo(void)
251 {
252 }
253 
254 static inline struct page *follow_huge_pd(struct vm_area_struct *vma,
255 				unsigned long address, hugepd_t hpd, int flags,
256 				int pdshift)
257 {
258 	return NULL;
259 }
260 
261 static inline struct page *follow_huge_pmd(struct mm_struct *mm,
262 				unsigned long address, pmd_t *pmd, int flags)
263 {
264 	return NULL;
265 }
266 
267 static inline struct page *follow_huge_pud(struct mm_struct *mm,
268 				unsigned long address, pud_t *pud, int flags)
269 {
270 	return NULL;
271 }
272 
273 static inline struct page *follow_huge_pgd(struct mm_struct *mm,
274 				unsigned long address, pgd_t *pgd, int flags)
275 {
276 	return NULL;
277 }
278 
279 static inline int prepare_hugepage_range(struct file *file,
280 				unsigned long addr, unsigned long len)
281 {
282 	return -EINVAL;
283 }
284 
285 static inline int pmd_huge(pmd_t pmd)
286 {
287 	return 0;
288 }
289 
290 static inline int pud_huge(pud_t pud)
291 {
292 	return 0;
293 }
294 
295 static inline int is_hugepage_only_range(struct mm_struct *mm,
296 					unsigned long addr, unsigned long len)
297 {
298 	return 0;
299 }
300 
301 static inline void hugetlb_free_pgd_range(struct mmu_gather *tlb,
302 				unsigned long addr, unsigned long end,
303 				unsigned long floor, unsigned long ceiling)
304 {
305 	BUG();
306 }
307 
308 static inline int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm,
309 						pte_t *dst_pte,
310 						struct vm_area_struct *dst_vma,
311 						unsigned long dst_addr,
312 						unsigned long src_addr,
313 						struct page **pagep)
314 {
315 	BUG();
316 	return 0;
317 }
318 
319 static inline pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr,
320 					unsigned long sz)
321 {
322 	return NULL;
323 }
324 
325 static inline bool isolate_huge_page(struct page *page, struct list_head *list)
326 {
327 	return false;
328 }
329 
330 static inline void putback_active_hugepage(struct page *page)
331 {
332 }
333 
334 static inline void move_hugetlb_state(struct page *oldpage,
335 					struct page *newpage, int reason)
336 {
337 }
338 
339 static inline unsigned long hugetlb_change_protection(
340 			struct vm_area_struct *vma, unsigned long address,
341 			unsigned long end, pgprot_t newprot)
342 {
343 	return 0;
344 }
345 
346 static inline void __unmap_hugepage_range_final(struct mmu_gather *tlb,
347 			struct vm_area_struct *vma, unsigned long start,
348 			unsigned long end, struct page *ref_page)
349 {
350 	BUG();
351 }
352 
353 static inline void __unmap_hugepage_range(struct mmu_gather *tlb,
354 			struct vm_area_struct *vma, unsigned long start,
355 			unsigned long end, struct page *ref_page)
356 {
357 	BUG();
358 }
359 
360 static inline vm_fault_t hugetlb_fault(struct mm_struct *mm,
361 			struct vm_area_struct *vma, unsigned long address,
362 			unsigned int flags)
363 {
364 	BUG();
365 	return 0;
366 }
367 
368 #endif /* !CONFIG_HUGETLB_PAGE */
369 /*
370  * hugepages at page global directory. If arch support
371  * hugepages at pgd level, they need to define this.
372  */
373 #ifndef pgd_huge
374 #define pgd_huge(x)	0
375 #endif
376 #ifndef p4d_huge
377 #define p4d_huge(x)	0
378 #endif
379 
380 #ifndef pgd_write
381 static inline int pgd_write(pgd_t pgd)
382 {
383 	BUG();
384 	return 0;
385 }
386 #endif
387 
388 #define HUGETLB_ANON_FILE "anon_hugepage"
389 
390 enum {
391 	/*
392 	 * The file will be used as an shm file so shmfs accounting rules
393 	 * apply
394 	 */
395 	HUGETLB_SHMFS_INODE     = 1,
396 	/*
397 	 * The file is being created on the internal vfs mount and shmfs
398 	 * accounting rules do not apply
399 	 */
400 	HUGETLB_ANONHUGE_INODE  = 2,
401 };
402 
403 #ifdef CONFIG_HUGETLBFS
404 struct hugetlbfs_sb_info {
405 	long	max_inodes;   /* inodes allowed */
406 	long	free_inodes;  /* inodes free */
407 	spinlock_t	stat_lock;
408 	struct hstate *hstate;
409 	struct hugepage_subpool *spool;
410 	kuid_t	uid;
411 	kgid_t	gid;
412 	umode_t mode;
413 };
414 
415 static inline struct hugetlbfs_sb_info *HUGETLBFS_SB(struct super_block *sb)
416 {
417 	return sb->s_fs_info;
418 }
419 
420 struct hugetlbfs_inode_info {
421 	struct shared_policy policy;
422 	struct inode vfs_inode;
423 	unsigned int seals;
424 };
425 
426 static inline struct hugetlbfs_inode_info *HUGETLBFS_I(struct inode *inode)
427 {
428 	return container_of(inode, struct hugetlbfs_inode_info, vfs_inode);
429 }
430 
431 extern const struct file_operations hugetlbfs_file_operations;
432 extern const struct vm_operations_struct hugetlb_vm_ops;
433 struct file *hugetlb_file_setup(const char *name, size_t size, vm_flags_t acct,
434 				struct user_struct **user, int creat_flags,
435 				int page_size_log);
436 
437 static inline bool is_file_hugepages(struct file *file)
438 {
439 	if (file->f_op == &hugetlbfs_file_operations)
440 		return true;
441 
442 	return is_file_shm_hugepages(file);
443 }
444 
445 static inline struct hstate *hstate_inode(struct inode *i)
446 {
447 	return HUGETLBFS_SB(i->i_sb)->hstate;
448 }
449 #else /* !CONFIG_HUGETLBFS */
450 
451 #define is_file_hugepages(file)			false
452 static inline struct file *
453 hugetlb_file_setup(const char *name, size_t size, vm_flags_t acctflag,
454 		struct user_struct **user, int creat_flags,
455 		int page_size_log)
456 {
457 	return ERR_PTR(-ENOSYS);
458 }
459 
460 static inline struct hstate *hstate_inode(struct inode *i)
461 {
462 	return NULL;
463 }
464 #endif /* !CONFIG_HUGETLBFS */
465 
466 #ifdef HAVE_ARCH_HUGETLB_UNMAPPED_AREA
467 unsigned long hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
468 					unsigned long len, unsigned long pgoff,
469 					unsigned long flags);
470 #endif /* HAVE_ARCH_HUGETLB_UNMAPPED_AREA */
471 
472 #ifdef CONFIG_HUGETLB_PAGE
473 
474 #define HSTATE_NAME_LEN 32
475 /* Defines one hugetlb page size */
476 struct hstate {
477 	int next_nid_to_alloc;
478 	int next_nid_to_free;
479 	unsigned int order;
480 	unsigned long mask;
481 	unsigned long max_huge_pages;
482 	unsigned long nr_huge_pages;
483 	unsigned long free_huge_pages;
484 	unsigned long resv_huge_pages;
485 	unsigned long surplus_huge_pages;
486 	unsigned long nr_overcommit_huge_pages;
487 	struct list_head hugepage_activelist;
488 	struct list_head hugepage_freelists[MAX_NUMNODES];
489 	unsigned int nr_huge_pages_node[MAX_NUMNODES];
490 	unsigned int free_huge_pages_node[MAX_NUMNODES];
491 	unsigned int surplus_huge_pages_node[MAX_NUMNODES];
492 #ifdef CONFIG_CGROUP_HUGETLB
493 	/* cgroup control files */
494 	struct cftype cgroup_files_dfl[7];
495 	struct cftype cgroup_files_legacy[9];
496 #endif
497 	char name[HSTATE_NAME_LEN];
498 };
499 
500 struct huge_bootmem_page {
501 	struct list_head list;
502 	struct hstate *hstate;
503 };
504 
505 struct page *alloc_huge_page(struct vm_area_struct *vma,
506 				unsigned long addr, int avoid_reserve);
507 struct page *alloc_huge_page_node(struct hstate *h, int nid);
508 struct page *alloc_huge_page_nodemask(struct hstate *h, int preferred_nid,
509 				nodemask_t *nmask);
510 struct page *alloc_huge_page_vma(struct hstate *h, struct vm_area_struct *vma,
511 				unsigned long address);
512 struct page *alloc_migrate_huge_page(struct hstate *h, gfp_t gfp_mask,
513 				     int nid, nodemask_t *nmask);
514 int huge_add_to_page_cache(struct page *page, struct address_space *mapping,
515 			pgoff_t idx);
516 
517 /* arch callback */
518 int __init __alloc_bootmem_huge_page(struct hstate *h);
519 int __init alloc_bootmem_huge_page(struct hstate *h);
520 
521 void __init hugetlb_add_hstate(unsigned order);
522 bool __init arch_hugetlb_valid_size(unsigned long size);
523 struct hstate *size_to_hstate(unsigned long size);
524 
525 #ifndef HUGE_MAX_HSTATE
526 #define HUGE_MAX_HSTATE 1
527 #endif
528 
529 extern struct hstate hstates[HUGE_MAX_HSTATE];
530 extern unsigned int default_hstate_idx;
531 
532 #define default_hstate (hstates[default_hstate_idx])
533 
534 static inline struct hstate *hstate_file(struct file *f)
535 {
536 	return hstate_inode(file_inode(f));
537 }
538 
539 static inline struct hstate *hstate_sizelog(int page_size_log)
540 {
541 	if (!page_size_log)
542 		return &default_hstate;
543 
544 	return size_to_hstate(1UL << page_size_log);
545 }
546 
547 static inline struct hstate *hstate_vma(struct vm_area_struct *vma)
548 {
549 	return hstate_file(vma->vm_file);
550 }
551 
552 static inline unsigned long huge_page_size(struct hstate *h)
553 {
554 	return (unsigned long)PAGE_SIZE << h->order;
555 }
556 
557 extern unsigned long vma_kernel_pagesize(struct vm_area_struct *vma);
558 
559 extern unsigned long vma_mmu_pagesize(struct vm_area_struct *vma);
560 
561 static inline unsigned long huge_page_mask(struct hstate *h)
562 {
563 	return h->mask;
564 }
565 
566 static inline unsigned int huge_page_order(struct hstate *h)
567 {
568 	return h->order;
569 }
570 
571 static inline unsigned huge_page_shift(struct hstate *h)
572 {
573 	return h->order + PAGE_SHIFT;
574 }
575 
576 static inline bool hstate_is_gigantic(struct hstate *h)
577 {
578 	return huge_page_order(h) >= MAX_ORDER;
579 }
580 
581 static inline unsigned int pages_per_huge_page(struct hstate *h)
582 {
583 	return 1 << h->order;
584 }
585 
586 static inline unsigned int blocks_per_huge_page(struct hstate *h)
587 {
588 	return huge_page_size(h) / 512;
589 }
590 
591 #include <asm/hugetlb.h>
592 
593 #ifndef is_hugepage_only_range
594 static inline int is_hugepage_only_range(struct mm_struct *mm,
595 					unsigned long addr, unsigned long len)
596 {
597 	return 0;
598 }
599 #define is_hugepage_only_range is_hugepage_only_range
600 #endif
601 
602 #ifndef arch_clear_hugepage_flags
603 static inline void arch_clear_hugepage_flags(struct page *page) { }
604 #define arch_clear_hugepage_flags arch_clear_hugepage_flags
605 #endif
606 
607 #ifndef arch_make_huge_pte
608 static inline pte_t arch_make_huge_pte(pte_t entry, struct vm_area_struct *vma,
609 				       struct page *page, int writable)
610 {
611 	return entry;
612 }
613 #endif
614 
615 static inline struct hstate *page_hstate(struct page *page)
616 {
617 	VM_BUG_ON_PAGE(!PageHuge(page), page);
618 	return size_to_hstate(page_size(page));
619 }
620 
621 static inline unsigned hstate_index_to_shift(unsigned index)
622 {
623 	return hstates[index].order + PAGE_SHIFT;
624 }
625 
626 static inline int hstate_index(struct hstate *h)
627 {
628 	return h - hstates;
629 }
630 
631 pgoff_t __basepage_index(struct page *page);
632 
633 /* Return page->index in PAGE_SIZE units */
634 static inline pgoff_t basepage_index(struct page *page)
635 {
636 	if (!PageCompound(page))
637 		return page->index;
638 
639 	return __basepage_index(page);
640 }
641 
642 extern int dissolve_free_huge_page(struct page *page);
643 extern int dissolve_free_huge_pages(unsigned long start_pfn,
644 				    unsigned long end_pfn);
645 
646 #ifdef CONFIG_ARCH_ENABLE_HUGEPAGE_MIGRATION
647 #ifndef arch_hugetlb_migration_supported
648 static inline bool arch_hugetlb_migration_supported(struct hstate *h)
649 {
650 	if ((huge_page_shift(h) == PMD_SHIFT) ||
651 		(huge_page_shift(h) == PUD_SHIFT) ||
652 			(huge_page_shift(h) == PGDIR_SHIFT))
653 		return true;
654 	else
655 		return false;
656 }
657 #endif
658 #else
659 static inline bool arch_hugetlb_migration_supported(struct hstate *h)
660 {
661 	return false;
662 }
663 #endif
664 
665 static inline bool hugepage_migration_supported(struct hstate *h)
666 {
667 	return arch_hugetlb_migration_supported(h);
668 }
669 
670 /*
671  * Movability check is different as compared to migration check.
672  * It determines whether or not a huge page should be placed on
673  * movable zone or not. Movability of any huge page should be
674  * required only if huge page size is supported for migration.
675  * There wont be any reason for the huge page to be movable if
676  * it is not migratable to start with. Also the size of the huge
677  * page should be large enough to be placed under a movable zone
678  * and still feasible enough to be migratable. Just the presence
679  * in movable zone does not make the migration feasible.
680  *
681  * So even though large huge page sizes like the gigantic ones
682  * are migratable they should not be movable because its not
683  * feasible to migrate them from movable zone.
684  */
685 static inline bool hugepage_movable_supported(struct hstate *h)
686 {
687 	if (!hugepage_migration_supported(h))
688 		return false;
689 
690 	if (hstate_is_gigantic(h))
691 		return false;
692 	return true;
693 }
694 
695 static inline spinlock_t *huge_pte_lockptr(struct hstate *h,
696 					   struct mm_struct *mm, pte_t *pte)
697 {
698 	if (huge_page_size(h) == PMD_SIZE)
699 		return pmd_lockptr(mm, (pmd_t *) pte);
700 	VM_BUG_ON(huge_page_size(h) == PAGE_SIZE);
701 	return &mm->page_table_lock;
702 }
703 
704 #ifndef hugepages_supported
705 /*
706  * Some platform decide whether they support huge pages at boot
707  * time. Some of them, such as powerpc, set HPAGE_SHIFT to 0
708  * when there is no such support
709  */
710 #define hugepages_supported() (HPAGE_SHIFT != 0)
711 #endif
712 
713 void hugetlb_report_usage(struct seq_file *m, struct mm_struct *mm);
714 
715 static inline void hugetlb_count_add(long l, struct mm_struct *mm)
716 {
717 	atomic_long_add(l, &mm->hugetlb_usage);
718 }
719 
720 static inline void hugetlb_count_sub(long l, struct mm_struct *mm)
721 {
722 	atomic_long_sub(l, &mm->hugetlb_usage);
723 }
724 
725 #ifndef set_huge_swap_pte_at
726 static inline void set_huge_swap_pte_at(struct mm_struct *mm, unsigned long addr,
727 					pte_t *ptep, pte_t pte, unsigned long sz)
728 {
729 	set_huge_pte_at(mm, addr, ptep, pte);
730 }
731 #endif
732 
733 #ifndef huge_ptep_modify_prot_start
734 #define huge_ptep_modify_prot_start huge_ptep_modify_prot_start
735 static inline pte_t huge_ptep_modify_prot_start(struct vm_area_struct *vma,
736 						unsigned long addr, pte_t *ptep)
737 {
738 	return huge_ptep_get_and_clear(vma->vm_mm, addr, ptep);
739 }
740 #endif
741 
742 #ifndef huge_ptep_modify_prot_commit
743 #define huge_ptep_modify_prot_commit huge_ptep_modify_prot_commit
744 static inline void huge_ptep_modify_prot_commit(struct vm_area_struct *vma,
745 						unsigned long addr, pte_t *ptep,
746 						pte_t old_pte, pte_t pte)
747 {
748 	set_huge_pte_at(vma->vm_mm, addr, ptep, pte);
749 }
750 #endif
751 
752 #else	/* CONFIG_HUGETLB_PAGE */
753 struct hstate {};
754 
755 static inline struct page *alloc_huge_page(struct vm_area_struct *vma,
756 					   unsigned long addr,
757 					   int avoid_reserve)
758 {
759 	return NULL;
760 }
761 
762 static inline struct page *alloc_huge_page_node(struct hstate *h, int nid)
763 {
764 	return NULL;
765 }
766 
767 static inline struct page *
768 alloc_huge_page_nodemask(struct hstate *h, int preferred_nid, nodemask_t *nmask)
769 {
770 	return NULL;
771 }
772 
773 static inline struct page *alloc_huge_page_vma(struct hstate *h,
774 					       struct vm_area_struct *vma,
775 					       unsigned long address)
776 {
777 	return NULL;
778 }
779 
780 static inline int __alloc_bootmem_huge_page(struct hstate *h)
781 {
782 	return 0;
783 }
784 
785 static inline struct hstate *hstate_file(struct file *f)
786 {
787 	return NULL;
788 }
789 
790 static inline struct hstate *hstate_sizelog(int page_size_log)
791 {
792 	return NULL;
793 }
794 
795 static inline struct hstate *hstate_vma(struct vm_area_struct *vma)
796 {
797 	return NULL;
798 }
799 
800 static inline struct hstate *page_hstate(struct page *page)
801 {
802 	return NULL;
803 }
804 
805 static inline unsigned long huge_page_size(struct hstate *h)
806 {
807 	return PAGE_SIZE;
808 }
809 
810 static inline unsigned long huge_page_mask(struct hstate *h)
811 {
812 	return PAGE_MASK;
813 }
814 
815 static inline unsigned long vma_kernel_pagesize(struct vm_area_struct *vma)
816 {
817 	return PAGE_SIZE;
818 }
819 
820 static inline unsigned long vma_mmu_pagesize(struct vm_area_struct *vma)
821 {
822 	return PAGE_SIZE;
823 }
824 
825 static inline unsigned int huge_page_order(struct hstate *h)
826 {
827 	return 0;
828 }
829 
830 static inline unsigned int huge_page_shift(struct hstate *h)
831 {
832 	return PAGE_SHIFT;
833 }
834 
835 static inline bool hstate_is_gigantic(struct hstate *h)
836 {
837 	return false;
838 }
839 
840 static inline unsigned int pages_per_huge_page(struct hstate *h)
841 {
842 	return 1;
843 }
844 
845 static inline unsigned hstate_index_to_shift(unsigned index)
846 {
847 	return 0;
848 }
849 
850 static inline int hstate_index(struct hstate *h)
851 {
852 	return 0;
853 }
854 
855 static inline pgoff_t basepage_index(struct page *page)
856 {
857 	return page->index;
858 }
859 
860 static inline int dissolve_free_huge_page(struct page *page)
861 {
862 	return 0;
863 }
864 
865 static inline int dissolve_free_huge_pages(unsigned long start_pfn,
866 					   unsigned long end_pfn)
867 {
868 	return 0;
869 }
870 
871 static inline bool hugepage_migration_supported(struct hstate *h)
872 {
873 	return false;
874 }
875 
876 static inline bool hugepage_movable_supported(struct hstate *h)
877 {
878 	return false;
879 }
880 
881 static inline spinlock_t *huge_pte_lockptr(struct hstate *h,
882 					   struct mm_struct *mm, pte_t *pte)
883 {
884 	return &mm->page_table_lock;
885 }
886 
887 static inline void hugetlb_report_usage(struct seq_file *f, struct mm_struct *m)
888 {
889 }
890 
891 static inline void hugetlb_count_sub(long l, struct mm_struct *mm)
892 {
893 }
894 
895 static inline void set_huge_swap_pte_at(struct mm_struct *mm, unsigned long addr,
896 					pte_t *ptep, pte_t pte, unsigned long sz)
897 {
898 }
899 #endif	/* CONFIG_HUGETLB_PAGE */
900 
901 static inline spinlock_t *huge_pte_lock(struct hstate *h,
902 					struct mm_struct *mm, pte_t *pte)
903 {
904 	spinlock_t *ptl;
905 
906 	ptl = huge_pte_lockptr(h, mm, pte);
907 	spin_lock(ptl);
908 	return ptl;
909 }
910 
911 #if defined(CONFIG_HUGETLB_PAGE) && defined(CONFIG_CMA)
912 extern void __init hugetlb_cma_reserve(int order);
913 extern void __init hugetlb_cma_check(void);
914 #else
915 static inline __init void hugetlb_cma_reserve(int order)
916 {
917 }
918 static inline __init void hugetlb_cma_check(void)
919 {
920 }
921 #endif
922 
923 #endif /* _LINUX_HUGETLB_H */
924