xref: /linux/include/linux/huge_mm.h (revision beace86e61e465dba204a268ab3f3377153a4973)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_HUGE_MM_H
3 #define _LINUX_HUGE_MM_H
4 
5 #include <linux/mm_types.h>
6 
7 #include <linux/fs.h> /* only for vma_is_dax() */
8 #include <linux/kobject.h>
9 
10 vm_fault_t do_huge_pmd_anonymous_page(struct vm_fault *vmf);
11 int copy_huge_pmd(struct mm_struct *dst_mm, struct mm_struct *src_mm,
12 		  pmd_t *dst_pmd, pmd_t *src_pmd, unsigned long addr,
13 		  struct vm_area_struct *dst_vma, struct vm_area_struct *src_vma);
14 void huge_pmd_set_accessed(struct vm_fault *vmf);
15 int copy_huge_pud(struct mm_struct *dst_mm, struct mm_struct *src_mm,
16 		  pud_t *dst_pud, pud_t *src_pud, unsigned long addr,
17 		  struct vm_area_struct *vma);
18 
19 #ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
20 void huge_pud_set_accessed(struct vm_fault *vmf, pud_t orig_pud);
21 #else
22 static inline void huge_pud_set_accessed(struct vm_fault *vmf, pud_t orig_pud)
23 {
24 }
25 #endif
26 
27 vm_fault_t do_huge_pmd_wp_page(struct vm_fault *vmf);
28 bool madvise_free_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma,
29 			   pmd_t *pmd, unsigned long addr, unsigned long next);
30 int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma, pmd_t *pmd,
31 		 unsigned long addr);
32 int zap_huge_pud(struct mmu_gather *tlb, struct vm_area_struct *vma, pud_t *pud,
33 		 unsigned long addr);
34 bool move_huge_pmd(struct vm_area_struct *vma, unsigned long old_addr,
35 		   unsigned long new_addr, pmd_t *old_pmd, pmd_t *new_pmd);
36 int change_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma,
37 		    pmd_t *pmd, unsigned long addr, pgprot_t newprot,
38 		    unsigned long cp_flags);
39 
40 vm_fault_t vmf_insert_pfn_pmd(struct vm_fault *vmf, unsigned long pfn,
41 			      bool write);
42 vm_fault_t vmf_insert_pfn_pud(struct vm_fault *vmf, unsigned long pfn,
43 			      bool write);
44 vm_fault_t vmf_insert_folio_pmd(struct vm_fault *vmf, struct folio *folio,
45 				bool write);
46 vm_fault_t vmf_insert_folio_pud(struct vm_fault *vmf, struct folio *folio,
47 				bool write);
48 
49 enum transparent_hugepage_flag {
50 	TRANSPARENT_HUGEPAGE_UNSUPPORTED,
51 	TRANSPARENT_HUGEPAGE_FLAG,
52 	TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG,
53 	TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG,
54 	TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_FLAG,
55 	TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG,
56 	TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG,
57 	TRANSPARENT_HUGEPAGE_DEFRAG_KHUGEPAGED_FLAG,
58 	TRANSPARENT_HUGEPAGE_USE_ZERO_PAGE_FLAG,
59 };
60 
61 struct kobject;
62 struct kobj_attribute;
63 
64 ssize_t single_hugepage_flag_store(struct kobject *kobj,
65 				   struct kobj_attribute *attr,
66 				   const char *buf, size_t count,
67 				   enum transparent_hugepage_flag flag);
68 ssize_t single_hugepage_flag_show(struct kobject *kobj,
69 				  struct kobj_attribute *attr, char *buf,
70 				  enum transparent_hugepage_flag flag);
71 extern struct kobj_attribute shmem_enabled_attr;
72 extern struct kobj_attribute thpsize_shmem_enabled_attr;
73 
74 /*
75  * Mask of all large folio orders supported for anonymous THP; all orders up to
76  * and including PMD_ORDER, except order-0 (which is not "huge") and order-1
77  * (which is a limitation of the THP implementation).
78  */
79 #define THP_ORDERS_ALL_ANON	((BIT(PMD_ORDER + 1) - 1) & ~(BIT(0) | BIT(1)))
80 
81 /*
82  * Mask of all large folio orders supported for file THP. Folios in a DAX
83  * file is never split and the MAX_PAGECACHE_ORDER limit does not apply to
84  * it.  Same to PFNMAPs where there's neither page* nor pagecache.
85  */
86 #define THP_ORDERS_ALL_SPECIAL		\
87 	(BIT(PMD_ORDER) | BIT(PUD_ORDER))
88 #define THP_ORDERS_ALL_FILE_DEFAULT	\
89 	((BIT(MAX_PAGECACHE_ORDER + 1) - 1) & ~BIT(0))
90 
91 /*
92  * Mask of all large folio orders supported for THP.
93  */
94 #define THP_ORDERS_ALL	\
95 	(THP_ORDERS_ALL_ANON | THP_ORDERS_ALL_SPECIAL | THP_ORDERS_ALL_FILE_DEFAULT)
96 
97 #define TVA_SMAPS		(1 << 0)	/* Will be used for procfs */
98 #define TVA_IN_PF		(1 << 1)	/* Page fault handler */
99 #define TVA_ENFORCE_SYSFS	(1 << 2)	/* Obey sysfs configuration */
100 
101 #define thp_vma_allowable_order(vma, vm_flags, tva_flags, order) \
102 	(!!thp_vma_allowable_orders(vma, vm_flags, tva_flags, BIT(order)))
103 
104 #define split_folio(f) split_folio_to_list(f, NULL)
105 
106 #ifdef CONFIG_PGTABLE_HAS_HUGE_LEAVES
107 #define HPAGE_PMD_SHIFT PMD_SHIFT
108 #define HPAGE_PUD_SHIFT PUD_SHIFT
109 #else
110 #define HPAGE_PMD_SHIFT ({ BUILD_BUG(); 0; })
111 #define HPAGE_PUD_SHIFT ({ BUILD_BUG(); 0; })
112 #endif
113 
114 #define HPAGE_PMD_ORDER (HPAGE_PMD_SHIFT-PAGE_SHIFT)
115 #define HPAGE_PMD_NR (1<<HPAGE_PMD_ORDER)
116 #define HPAGE_PMD_MASK	(~(HPAGE_PMD_SIZE - 1))
117 #define HPAGE_PMD_SIZE	((1UL) << HPAGE_PMD_SHIFT)
118 
119 #define HPAGE_PUD_ORDER (HPAGE_PUD_SHIFT-PAGE_SHIFT)
120 #define HPAGE_PUD_NR (1<<HPAGE_PUD_ORDER)
121 #define HPAGE_PUD_MASK	(~(HPAGE_PUD_SIZE - 1))
122 #define HPAGE_PUD_SIZE	((1UL) << HPAGE_PUD_SHIFT)
123 
124 enum mthp_stat_item {
125 	MTHP_STAT_ANON_FAULT_ALLOC,
126 	MTHP_STAT_ANON_FAULT_FALLBACK,
127 	MTHP_STAT_ANON_FAULT_FALLBACK_CHARGE,
128 	MTHP_STAT_ZSWPOUT,
129 	MTHP_STAT_SWPIN,
130 	MTHP_STAT_SWPIN_FALLBACK,
131 	MTHP_STAT_SWPIN_FALLBACK_CHARGE,
132 	MTHP_STAT_SWPOUT,
133 	MTHP_STAT_SWPOUT_FALLBACK,
134 	MTHP_STAT_SHMEM_ALLOC,
135 	MTHP_STAT_SHMEM_FALLBACK,
136 	MTHP_STAT_SHMEM_FALLBACK_CHARGE,
137 	MTHP_STAT_SPLIT,
138 	MTHP_STAT_SPLIT_FAILED,
139 	MTHP_STAT_SPLIT_DEFERRED,
140 	MTHP_STAT_NR_ANON,
141 	MTHP_STAT_NR_ANON_PARTIALLY_MAPPED,
142 	__MTHP_STAT_COUNT
143 };
144 
145 #if defined(CONFIG_TRANSPARENT_HUGEPAGE) && defined(CONFIG_SYSFS)
146 struct mthp_stat {
147 	unsigned long stats[ilog2(MAX_PTRS_PER_PTE) + 1][__MTHP_STAT_COUNT];
148 };
149 
150 DECLARE_PER_CPU(struct mthp_stat, mthp_stats);
151 
152 static inline void mod_mthp_stat(int order, enum mthp_stat_item item, int delta)
153 {
154 	if (order <= 0 || order > PMD_ORDER)
155 		return;
156 
157 	this_cpu_add(mthp_stats.stats[order][item], delta);
158 }
159 
160 static inline void count_mthp_stat(int order, enum mthp_stat_item item)
161 {
162 	mod_mthp_stat(order, item, 1);
163 }
164 
165 #else
166 static inline void mod_mthp_stat(int order, enum mthp_stat_item item, int delta)
167 {
168 }
169 
170 static inline void count_mthp_stat(int order, enum mthp_stat_item item)
171 {
172 }
173 #endif
174 
175 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
176 
177 extern unsigned long transparent_hugepage_flags;
178 extern unsigned long huge_anon_orders_always;
179 extern unsigned long huge_anon_orders_madvise;
180 extern unsigned long huge_anon_orders_inherit;
181 
182 static inline bool hugepage_global_enabled(void)
183 {
184 	return transparent_hugepage_flags &
185 			((1<<TRANSPARENT_HUGEPAGE_FLAG) |
186 			(1<<TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG));
187 }
188 
189 static inline bool hugepage_global_always(void)
190 {
191 	return transparent_hugepage_flags &
192 			(1<<TRANSPARENT_HUGEPAGE_FLAG);
193 }
194 
195 static inline int highest_order(unsigned long orders)
196 {
197 	return fls_long(orders) - 1;
198 }
199 
200 static inline int next_order(unsigned long *orders, int prev)
201 {
202 	*orders &= ~BIT(prev);
203 	return highest_order(*orders);
204 }
205 
206 /*
207  * Do the below checks:
208  *   - For file vma, check if the linear page offset of vma is
209  *     order-aligned within the file.  The hugepage is
210  *     guaranteed to be order-aligned within the file, but we must
211  *     check that the order-aligned addresses in the VMA map to
212  *     order-aligned offsets within the file, else the hugepage will
213  *     not be mappable.
214  *   - For all vmas, check if the haddr is in an aligned hugepage
215  *     area.
216  */
217 static inline bool thp_vma_suitable_order(struct vm_area_struct *vma,
218 		unsigned long addr, int order)
219 {
220 	unsigned long hpage_size = PAGE_SIZE << order;
221 	unsigned long haddr;
222 
223 	/* Don't have to check pgoff for anonymous vma */
224 	if (!vma_is_anonymous(vma)) {
225 		if (!IS_ALIGNED((vma->vm_start >> PAGE_SHIFT) - vma->vm_pgoff,
226 				hpage_size >> PAGE_SHIFT))
227 			return false;
228 	}
229 
230 	haddr = ALIGN_DOWN(addr, hpage_size);
231 
232 	if (haddr < vma->vm_start || haddr + hpage_size > vma->vm_end)
233 		return false;
234 	return true;
235 }
236 
237 /*
238  * Filter the bitfield of input orders to the ones suitable for use in the vma.
239  * See thp_vma_suitable_order().
240  * All orders that pass the checks are returned as a bitfield.
241  */
242 static inline unsigned long thp_vma_suitable_orders(struct vm_area_struct *vma,
243 		unsigned long addr, unsigned long orders)
244 {
245 	int order;
246 
247 	/*
248 	 * Iterate over orders, highest to lowest, removing orders that don't
249 	 * meet alignment requirements from the set. Exit loop at first order
250 	 * that meets requirements, since all lower orders must also meet
251 	 * requirements.
252 	 */
253 
254 	order = highest_order(orders);
255 
256 	while (orders) {
257 		if (thp_vma_suitable_order(vma, addr, order))
258 			break;
259 		order = next_order(&orders, order);
260 	}
261 
262 	return orders;
263 }
264 
265 unsigned long __thp_vma_allowable_orders(struct vm_area_struct *vma,
266 					 vm_flags_t vm_flags,
267 					 unsigned long tva_flags,
268 					 unsigned long orders);
269 
270 /**
271  * thp_vma_allowable_orders - determine hugepage orders that are allowed for vma
272  * @vma:  the vm area to check
273  * @vm_flags: use these vm_flags instead of vma->vm_flags
274  * @tva_flags: Which TVA flags to honour
275  * @orders: bitfield of all orders to consider
276  *
277  * Calculates the intersection of the requested hugepage orders and the allowed
278  * hugepage orders for the provided vma. Permitted orders are encoded as a set
279  * bit at the corresponding bit position (bit-2 corresponds to order-2, bit-3
280  * corresponds to order-3, etc). Order-0 is never considered a hugepage order.
281  *
282  * Return: bitfield of orders allowed for hugepage in the vma. 0 if no hugepage
283  * orders are allowed.
284  */
285 static inline
286 unsigned long thp_vma_allowable_orders(struct vm_area_struct *vma,
287 				       vm_flags_t vm_flags,
288 				       unsigned long tva_flags,
289 				       unsigned long orders)
290 {
291 	/* Optimization to check if required orders are enabled early. */
292 	if ((tva_flags & TVA_ENFORCE_SYSFS) && vma_is_anonymous(vma)) {
293 		unsigned long mask = READ_ONCE(huge_anon_orders_always);
294 
295 		if (vm_flags & VM_HUGEPAGE)
296 			mask |= READ_ONCE(huge_anon_orders_madvise);
297 		if (hugepage_global_always() ||
298 		    ((vm_flags & VM_HUGEPAGE) && hugepage_global_enabled()))
299 			mask |= READ_ONCE(huge_anon_orders_inherit);
300 
301 		orders &= mask;
302 		if (!orders)
303 			return 0;
304 	}
305 
306 	return __thp_vma_allowable_orders(vma, vm_flags, tva_flags, orders);
307 }
308 
309 struct thpsize {
310 	struct kobject kobj;
311 	struct list_head node;
312 	int order;
313 };
314 
315 #define to_thpsize(kobj) container_of(kobj, struct thpsize, kobj)
316 
317 #define transparent_hugepage_use_zero_page()				\
318 	(transparent_hugepage_flags &					\
319 	 (1<<TRANSPARENT_HUGEPAGE_USE_ZERO_PAGE_FLAG))
320 
321 static inline bool vma_thp_disabled(struct vm_area_struct *vma,
322 		vm_flags_t vm_flags)
323 {
324 	/*
325 	 * Explicitly disabled through madvise or prctl, or some
326 	 * architectures may disable THP for some mappings, for
327 	 * example, s390 kvm.
328 	 */
329 	return (vm_flags & VM_NOHUGEPAGE) ||
330 	       test_bit(MMF_DISABLE_THP, &vma->vm_mm->flags);
331 }
332 
333 static inline bool thp_disabled_by_hw(void)
334 {
335 	/* If the hardware/firmware marked hugepage support disabled. */
336 	return transparent_hugepage_flags & (1 << TRANSPARENT_HUGEPAGE_UNSUPPORTED);
337 }
338 
339 unsigned long thp_get_unmapped_area(struct file *filp, unsigned long addr,
340 		unsigned long len, unsigned long pgoff, unsigned long flags);
341 unsigned long thp_get_unmapped_area_vmflags(struct file *filp, unsigned long addr,
342 		unsigned long len, unsigned long pgoff, unsigned long flags,
343 		vm_flags_t vm_flags);
344 
345 bool can_split_folio(struct folio *folio, int caller_pins, int *pextra_pins);
346 int split_huge_page_to_list_to_order(struct page *page, struct list_head *list,
347 		unsigned int new_order);
348 int min_order_for_split(struct folio *folio);
349 int split_folio_to_list(struct folio *folio, struct list_head *list);
350 bool uniform_split_supported(struct folio *folio, unsigned int new_order,
351 		bool warns);
352 bool non_uniform_split_supported(struct folio *folio, unsigned int new_order,
353 		bool warns);
354 int folio_split(struct folio *folio, unsigned int new_order, struct page *page,
355 		struct list_head *list);
356 /*
357  * try_folio_split - try to split a @folio at @page using non uniform split.
358  * @folio: folio to be split
359  * @page: split to order-0 at the given page
360  * @list: store the after-split folios
361  *
362  * Try to split a @folio at @page using non uniform split to order-0, if
363  * non uniform split is not supported, fall back to uniform split.
364  *
365  * Return: 0: split is successful, otherwise split failed.
366  */
367 static inline int try_folio_split(struct folio *folio, struct page *page,
368 		struct list_head *list)
369 {
370 	int ret = min_order_for_split(folio);
371 
372 	if (ret < 0)
373 		return ret;
374 
375 	if (!non_uniform_split_supported(folio, 0, false))
376 		return split_huge_page_to_list_to_order(&folio->page, list,
377 				ret);
378 	return folio_split(folio, ret, page, list);
379 }
380 static inline int split_huge_page(struct page *page)
381 {
382 	struct folio *folio = page_folio(page);
383 	int ret = min_order_for_split(folio);
384 
385 	if (ret < 0)
386 		return ret;
387 
388 	/*
389 	 * split_huge_page() locks the page before splitting and
390 	 * expects the same page that has been split to be locked when
391 	 * returned. split_folio(page_folio(page)) cannot be used here
392 	 * because it converts the page to folio and passes the head
393 	 * page to be split.
394 	 */
395 	return split_huge_page_to_list_to_order(page, NULL, ret);
396 }
397 void deferred_split_folio(struct folio *folio, bool partially_mapped);
398 
399 void __split_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
400 		unsigned long address, bool freeze);
401 
402 #define split_huge_pmd(__vma, __pmd, __address)				\
403 	do {								\
404 		pmd_t *____pmd = (__pmd);				\
405 		if (is_swap_pmd(*____pmd) || pmd_trans_huge(*____pmd))	\
406 			__split_huge_pmd(__vma, __pmd, __address,	\
407 					 false);			\
408 	}  while (0)
409 
410 void split_huge_pmd_address(struct vm_area_struct *vma, unsigned long address,
411 		bool freeze);
412 
413 void __split_huge_pud(struct vm_area_struct *vma, pud_t *pud,
414 		unsigned long address);
415 
416 #ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
417 int change_huge_pud(struct mmu_gather *tlb, struct vm_area_struct *vma,
418 		    pud_t *pudp, unsigned long addr, pgprot_t newprot,
419 		    unsigned long cp_flags);
420 #else
421 static inline int
422 change_huge_pud(struct mmu_gather *tlb, struct vm_area_struct *vma,
423 		pud_t *pudp, unsigned long addr, pgprot_t newprot,
424 		unsigned long cp_flags) { return 0; }
425 #endif
426 
427 #define split_huge_pud(__vma, __pud, __address)				\
428 	do {								\
429 		pud_t *____pud = (__pud);				\
430 		if (pud_trans_huge(*____pud))				\
431 			__split_huge_pud(__vma, __pud, __address);	\
432 	}  while (0)
433 
434 int hugepage_madvise(struct vm_area_struct *vma, vm_flags_t *vm_flags,
435 		     int advice);
436 int madvise_collapse(struct vm_area_struct *vma, unsigned long start,
437 		     unsigned long end, bool *lock_dropped);
438 void vma_adjust_trans_huge(struct vm_area_struct *vma, unsigned long start,
439 			   unsigned long end, struct vm_area_struct *next);
440 spinlock_t *__pmd_trans_huge_lock(pmd_t *pmd, struct vm_area_struct *vma);
441 spinlock_t *__pud_trans_huge_lock(pud_t *pud, struct vm_area_struct *vma);
442 
443 static inline int is_swap_pmd(pmd_t pmd)
444 {
445 	return !pmd_none(pmd) && !pmd_present(pmd);
446 }
447 
448 /* mmap_lock must be held on entry */
449 static inline spinlock_t *pmd_trans_huge_lock(pmd_t *pmd,
450 		struct vm_area_struct *vma)
451 {
452 	if (is_swap_pmd(*pmd) || pmd_trans_huge(*pmd))
453 		return __pmd_trans_huge_lock(pmd, vma);
454 	else
455 		return NULL;
456 }
457 static inline spinlock_t *pud_trans_huge_lock(pud_t *pud,
458 		struct vm_area_struct *vma)
459 {
460 	if (pud_trans_huge(*pud))
461 		return __pud_trans_huge_lock(pud, vma);
462 	else
463 		return NULL;
464 }
465 
466 /**
467  * folio_test_pmd_mappable - Can we map this folio with a PMD?
468  * @folio: The folio to test
469  */
470 static inline bool folio_test_pmd_mappable(struct folio *folio)
471 {
472 	return folio_order(folio) >= HPAGE_PMD_ORDER;
473 }
474 
475 vm_fault_t do_huge_pmd_numa_page(struct vm_fault *vmf);
476 
477 extern struct folio *huge_zero_folio;
478 extern unsigned long huge_zero_pfn;
479 
480 static inline bool is_huge_zero_folio(const struct folio *folio)
481 {
482 	return READ_ONCE(huge_zero_folio) == folio;
483 }
484 
485 static inline bool is_huge_zero_pfn(unsigned long pfn)
486 {
487 	return READ_ONCE(huge_zero_pfn) == (pfn & ~(HPAGE_PMD_NR - 1));
488 }
489 
490 static inline bool is_huge_zero_pmd(pmd_t pmd)
491 {
492 	return pmd_present(pmd) && is_huge_zero_pfn(pmd_pfn(pmd));
493 }
494 
495 struct folio *mm_get_huge_zero_folio(struct mm_struct *mm);
496 void mm_put_huge_zero_folio(struct mm_struct *mm);
497 
498 static inline bool thp_migration_supported(void)
499 {
500 	return IS_ENABLED(CONFIG_ARCH_ENABLE_THP_MIGRATION);
501 }
502 
503 void split_huge_pmd_locked(struct vm_area_struct *vma, unsigned long address,
504 			   pmd_t *pmd, bool freeze);
505 bool unmap_huge_pmd_locked(struct vm_area_struct *vma, unsigned long addr,
506 			   pmd_t *pmdp, struct folio *folio);
507 
508 #else /* CONFIG_TRANSPARENT_HUGEPAGE */
509 
510 static inline bool folio_test_pmd_mappable(struct folio *folio)
511 {
512 	return false;
513 }
514 
515 static inline bool thp_vma_suitable_order(struct vm_area_struct *vma,
516 		unsigned long addr, int order)
517 {
518 	return false;
519 }
520 
521 static inline unsigned long thp_vma_suitable_orders(struct vm_area_struct *vma,
522 		unsigned long addr, unsigned long orders)
523 {
524 	return 0;
525 }
526 
527 static inline unsigned long thp_vma_allowable_orders(struct vm_area_struct *vma,
528 					vm_flags_t vm_flags,
529 					unsigned long tva_flags,
530 					unsigned long orders)
531 {
532 	return 0;
533 }
534 
535 #define transparent_hugepage_flags 0UL
536 
537 #define thp_get_unmapped_area	NULL
538 
539 static inline unsigned long
540 thp_get_unmapped_area_vmflags(struct file *filp, unsigned long addr,
541 			      unsigned long len, unsigned long pgoff,
542 			      unsigned long flags, vm_flags_t vm_flags)
543 {
544 	return 0;
545 }
546 
547 static inline bool
548 can_split_folio(struct folio *folio, int caller_pins, int *pextra_pins)
549 {
550 	return false;
551 }
552 static inline int
553 split_huge_page_to_list_to_order(struct page *page, struct list_head *list,
554 		unsigned int new_order)
555 {
556 	return 0;
557 }
558 static inline int split_huge_page(struct page *page)
559 {
560 	return 0;
561 }
562 
563 static inline int split_folio_to_list(struct folio *folio, struct list_head *list)
564 {
565 	return 0;
566 }
567 
568 static inline int try_folio_split(struct folio *folio, struct page *page,
569 		struct list_head *list)
570 {
571 	return 0;
572 }
573 
574 static inline void deferred_split_folio(struct folio *folio, bool partially_mapped) {}
575 #define split_huge_pmd(__vma, __pmd, __address)	\
576 	do { } while (0)
577 
578 static inline void __split_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
579 		unsigned long address, bool freeze) {}
580 static inline void split_huge_pmd_address(struct vm_area_struct *vma,
581 		unsigned long address, bool freeze) {}
582 static inline void split_huge_pmd_locked(struct vm_area_struct *vma,
583 					 unsigned long address, pmd_t *pmd,
584 					 bool freeze) {}
585 
586 static inline bool unmap_huge_pmd_locked(struct vm_area_struct *vma,
587 					 unsigned long addr, pmd_t *pmdp,
588 					 struct folio *folio)
589 {
590 	return false;
591 }
592 
593 #define split_huge_pud(__vma, __pmd, __address)	\
594 	do { } while (0)
595 
596 static inline int hugepage_madvise(struct vm_area_struct *vma,
597 				   vm_flags_t *vm_flags, int advice)
598 {
599 	return -EINVAL;
600 }
601 
602 static inline int madvise_collapse(struct vm_area_struct *vma,
603 				   unsigned long start,
604 				   unsigned long end, bool *lock_dropped)
605 {
606 	return -EINVAL;
607 }
608 
609 static inline void vma_adjust_trans_huge(struct vm_area_struct *vma,
610 					 unsigned long start,
611 					 unsigned long end,
612 					 struct vm_area_struct *next)
613 {
614 }
615 static inline int is_swap_pmd(pmd_t pmd)
616 {
617 	return 0;
618 }
619 static inline spinlock_t *pmd_trans_huge_lock(pmd_t *pmd,
620 		struct vm_area_struct *vma)
621 {
622 	return NULL;
623 }
624 static inline spinlock_t *pud_trans_huge_lock(pud_t *pud,
625 		struct vm_area_struct *vma)
626 {
627 	return NULL;
628 }
629 
630 static inline vm_fault_t do_huge_pmd_numa_page(struct vm_fault *vmf)
631 {
632 	return 0;
633 }
634 
635 static inline bool is_huge_zero_folio(const struct folio *folio)
636 {
637 	return false;
638 }
639 
640 static inline bool is_huge_zero_pfn(unsigned long pfn)
641 {
642 	return false;
643 }
644 
645 static inline bool is_huge_zero_pmd(pmd_t pmd)
646 {
647 	return false;
648 }
649 
650 static inline void mm_put_huge_zero_folio(struct mm_struct *mm)
651 {
652 	return;
653 }
654 
655 static inline struct page *follow_devmap_pmd(struct vm_area_struct *vma,
656 	unsigned long addr, pmd_t *pmd, int flags, struct dev_pagemap **pgmap)
657 {
658 	return NULL;
659 }
660 
661 static inline bool thp_migration_supported(void)
662 {
663 	return false;
664 }
665 
666 static inline int highest_order(unsigned long orders)
667 {
668 	return 0;
669 }
670 
671 static inline int next_order(unsigned long *orders, int prev)
672 {
673 	return 0;
674 }
675 
676 static inline void __split_huge_pud(struct vm_area_struct *vma, pud_t *pud,
677 				    unsigned long address)
678 {
679 }
680 
681 static inline int change_huge_pud(struct mmu_gather *tlb,
682 				  struct vm_area_struct *vma, pud_t *pudp,
683 				  unsigned long addr, pgprot_t newprot,
684 				  unsigned long cp_flags)
685 {
686 	return 0;
687 }
688 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
689 
690 static inline int split_folio_to_list_to_order(struct folio *folio,
691 		struct list_head *list, int new_order)
692 {
693 	return split_huge_page_to_list_to_order(&folio->page, list, new_order);
694 }
695 
696 static inline int split_folio_to_order(struct folio *folio, int new_order)
697 {
698 	return split_folio_to_list_to_order(folio, NULL, new_order);
699 }
700 
701 #endif /* _LINUX_HUGE_MM_H */
702