xref: /linux-6.15/include/linux/huge_mm.h (revision bb4e9af0) 
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_HUGE_MM_H
3 #define _LINUX_HUGE_MM_H
4 
5 #include <linux/sched/coredump.h>
6 #include <linux/mm_types.h>
7 
8 #include <linux/fs.h> /* only for vma_is_dax() */
9 
10 extern vm_fault_t do_huge_pmd_anonymous_page(struct vm_fault *vmf);
11 extern int copy_huge_pmd(struct mm_struct *dst_mm, struct mm_struct *src_mm,
12 			 pmd_t *dst_pmd, pmd_t *src_pmd, unsigned long addr,
13 			 struct vm_area_struct *vma);
14 extern void huge_pmd_set_accessed(struct vm_fault *vmf, pmd_t orig_pmd);
15 extern int copy_huge_pud(struct mm_struct *dst_mm, struct mm_struct *src_mm,
16 			 pud_t *dst_pud, pud_t *src_pud, unsigned long addr,
17 			 struct vm_area_struct *vma);
18 
19 #ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
20 extern void huge_pud_set_accessed(struct vm_fault *vmf, pud_t orig_pud);
21 #else
22 static inline void huge_pud_set_accessed(struct vm_fault *vmf, pud_t orig_pud)
23 {
24 }
25 #endif
26 
27 extern vm_fault_t do_huge_pmd_wp_page(struct vm_fault *vmf, pmd_t orig_pmd);
28 extern struct page *follow_trans_huge_pmd(struct vm_area_struct *vma,
29 					  unsigned long addr,
30 					  pmd_t *pmd,
31 					  unsigned int flags);
32 extern bool madvise_free_huge_pmd(struct mmu_gather *tlb,
33 			struct vm_area_struct *vma,
34 			pmd_t *pmd, unsigned long addr, unsigned long next);
35 extern int zap_huge_pmd(struct mmu_gather *tlb,
36 			struct vm_area_struct *vma,
37 			pmd_t *pmd, unsigned long addr);
38 extern int zap_huge_pud(struct mmu_gather *tlb,
39 			struct vm_area_struct *vma,
40 			pud_t *pud, unsigned long addr);
41 extern int mincore_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
42 			unsigned long addr, unsigned long end,
43 			unsigned char *vec);
44 extern bool move_huge_pmd(struct vm_area_struct *vma, unsigned long old_addr,
45 			 unsigned long new_addr, unsigned long old_end,
46 			 pmd_t *old_pmd, pmd_t *new_pmd);
47 extern int change_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
48 			unsigned long addr, pgprot_t newprot,
49 			int prot_numa);
50 vm_fault_t vmf_insert_pfn_pmd(struct vm_fault *vmf, pfn_t pfn, bool write);
51 vm_fault_t vmf_insert_pfn_pud(struct vm_fault *vmf, pfn_t pfn, bool write);
52 enum transparent_hugepage_flag {
53 	TRANSPARENT_HUGEPAGE_FLAG,
54 	TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG,
55 	TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG,
56 	TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_FLAG,
57 	TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG,
58 	TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG,
59 	TRANSPARENT_HUGEPAGE_DEFRAG_KHUGEPAGED_FLAG,
60 	TRANSPARENT_HUGEPAGE_USE_ZERO_PAGE_FLAG,
61 #ifdef CONFIG_DEBUG_VM
62 	TRANSPARENT_HUGEPAGE_DEBUG_COW_FLAG,
63 #endif
64 };
65 
66 struct kobject;
67 struct kobj_attribute;
68 
69 extern ssize_t single_hugepage_flag_store(struct kobject *kobj,
70 				 struct kobj_attribute *attr,
71 				 const char *buf, size_t count,
72 				 enum transparent_hugepage_flag flag);
73 extern ssize_t single_hugepage_flag_show(struct kobject *kobj,
74 				struct kobj_attribute *attr, char *buf,
75 				enum transparent_hugepage_flag flag);
76 extern struct kobj_attribute shmem_enabled_attr;
77 
78 #define HPAGE_PMD_ORDER (HPAGE_PMD_SHIFT-PAGE_SHIFT)
79 #define HPAGE_PMD_NR (1<<HPAGE_PMD_ORDER)
80 
81 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
82 #define HPAGE_PMD_SHIFT PMD_SHIFT
83 #define HPAGE_PMD_SIZE	((1UL) << HPAGE_PMD_SHIFT)
84 #define HPAGE_PMD_MASK	(~(HPAGE_PMD_SIZE - 1))
85 
86 #define HPAGE_PUD_SHIFT PUD_SHIFT
87 #define HPAGE_PUD_SIZE	((1UL) << HPAGE_PUD_SHIFT)
88 #define HPAGE_PUD_MASK	(~(HPAGE_PUD_SIZE - 1))
89 
90 extern bool is_vma_temporary_stack(struct vm_area_struct *vma);
91 
92 extern unsigned long transparent_hugepage_flags;
93 
94 /*
95  * to be used on vmas which are known to support THP.
96  * Use transparent_hugepage_enabled otherwise
97  */
98 static inline bool __transparent_hugepage_enabled(struct vm_area_struct *vma)
99 {
100 	if (vma->vm_flags & VM_NOHUGEPAGE)
101 		return false;
102 
103 	if (is_vma_temporary_stack(vma))
104 		return false;
105 
106 	if (test_bit(MMF_DISABLE_THP, &vma->vm_mm->flags))
107 		return false;
108 
109 	if (transparent_hugepage_flags & (1 << TRANSPARENT_HUGEPAGE_FLAG))
110 		return true;
111 
112 	if (vma_is_dax(vma))
113 		return true;
114 
115 	if (transparent_hugepage_flags &
116 				(1 << TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG))
117 		return !!(vma->vm_flags & VM_HUGEPAGE);
118 
119 	return false;
120 }
121 
122 bool transparent_hugepage_enabled(struct vm_area_struct *vma);
123 
124 #define HPAGE_CACHE_INDEX_MASK (HPAGE_PMD_NR - 1)
125 
126 static inline bool transhuge_vma_suitable(struct vm_area_struct *vma,
127 		unsigned long haddr)
128 {
129 	/* Don't have to check pgoff for anonymous vma */
130 	if (!vma_is_anonymous(vma)) {
131 		if (((vma->vm_start >> PAGE_SHIFT) & HPAGE_CACHE_INDEX_MASK) !=
132 			(vma->vm_pgoff & HPAGE_CACHE_INDEX_MASK))
133 			return false;
134 	}
135 
136 	if (haddr < vma->vm_start || haddr + HPAGE_PMD_SIZE > vma->vm_end)
137 		return false;
138 	return true;
139 }
140 
141 #define transparent_hugepage_use_zero_page()				\
142 	(transparent_hugepage_flags &					\
143 	 (1<<TRANSPARENT_HUGEPAGE_USE_ZERO_PAGE_FLAG))
144 #ifdef CONFIG_DEBUG_VM
145 #define transparent_hugepage_debug_cow()				\
146 	(transparent_hugepage_flags &					\
147 	 (1<<TRANSPARENT_HUGEPAGE_DEBUG_COW_FLAG))
148 #else /* CONFIG_DEBUG_VM */
149 #define transparent_hugepage_debug_cow() 0
150 #endif /* CONFIG_DEBUG_VM */
151 
152 extern unsigned long thp_get_unmapped_area(struct file *filp,
153 		unsigned long addr, unsigned long len, unsigned long pgoff,
154 		unsigned long flags);
155 
156 extern void prep_transhuge_page(struct page *page);
157 extern void free_transhuge_page(struct page *page);
158 
159 bool can_split_huge_page(struct page *page, int *pextra_pins);
160 int split_huge_page_to_list(struct page *page, struct list_head *list);
161 static inline int split_huge_page(struct page *page)
162 {
163 	return split_huge_page_to_list(page, NULL);
164 }
165 void deferred_split_huge_page(struct page *page);
166 
167 void __split_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
168 		unsigned long address, bool freeze, struct page *page);
169 
170 #define split_huge_pmd(__vma, __pmd, __address)				\
171 	do {								\
172 		pmd_t *____pmd = (__pmd);				\
173 		if (is_swap_pmd(*____pmd) || pmd_trans_huge(*____pmd)	\
174 					|| pmd_devmap(*____pmd))	\
175 			__split_huge_pmd(__vma, __pmd, __address,	\
176 						false, NULL);		\
177 	}  while (0)
178 
179 
180 void split_huge_pmd_address(struct vm_area_struct *vma, unsigned long address,
181 		bool freeze, struct page *page);
182 
183 void __split_huge_pud(struct vm_area_struct *vma, pud_t *pud,
184 		unsigned long address);
185 
186 #define split_huge_pud(__vma, __pud, __address)				\
187 	do {								\
188 		pud_t *____pud = (__pud);				\
189 		if (pud_trans_huge(*____pud)				\
190 					|| pud_devmap(*____pud))	\
191 			__split_huge_pud(__vma, __pud, __address);	\
192 	}  while (0)
193 
194 extern int hugepage_madvise(struct vm_area_struct *vma,
195 			    unsigned long *vm_flags, int advice);
196 extern void vma_adjust_trans_huge(struct vm_area_struct *vma,
197 				    unsigned long start,
198 				    unsigned long end,
199 				    long adjust_next);
200 extern spinlock_t *__pmd_trans_huge_lock(pmd_t *pmd,
201 		struct vm_area_struct *vma);
202 extern spinlock_t *__pud_trans_huge_lock(pud_t *pud,
203 		struct vm_area_struct *vma);
204 
205 static inline int is_swap_pmd(pmd_t pmd)
206 {
207 	return !pmd_none(pmd) && !pmd_present(pmd);
208 }
209 
210 /* mmap_sem must be held on entry */
211 static inline spinlock_t *pmd_trans_huge_lock(pmd_t *pmd,
212 		struct vm_area_struct *vma)
213 {
214 	VM_BUG_ON_VMA(!rwsem_is_locked(&vma->vm_mm->mmap_sem), vma);
215 	if (is_swap_pmd(*pmd) || pmd_trans_huge(*pmd) || pmd_devmap(*pmd))
216 		return __pmd_trans_huge_lock(pmd, vma);
217 	else
218 		return NULL;
219 }
220 static inline spinlock_t *pud_trans_huge_lock(pud_t *pud,
221 		struct vm_area_struct *vma)
222 {
223 	VM_BUG_ON_VMA(!rwsem_is_locked(&vma->vm_mm->mmap_sem), vma);
224 	if (pud_trans_huge(*pud) || pud_devmap(*pud))
225 		return __pud_trans_huge_lock(pud, vma);
226 	else
227 		return NULL;
228 }
229 static inline int hpage_nr_pages(struct page *page)
230 {
231 	if (unlikely(PageTransHuge(page)))
232 		return HPAGE_PMD_NR;
233 	return 1;
234 }
235 
236 struct page *follow_devmap_pmd(struct vm_area_struct *vma, unsigned long addr,
237 		pmd_t *pmd, int flags, struct dev_pagemap **pgmap);
238 struct page *follow_devmap_pud(struct vm_area_struct *vma, unsigned long addr,
239 		pud_t *pud, int flags, struct dev_pagemap **pgmap);
240 
241 extern vm_fault_t do_huge_pmd_numa_page(struct vm_fault *vmf, pmd_t orig_pmd);
242 
243 extern struct page *huge_zero_page;
244 
245 static inline bool is_huge_zero_page(struct page *page)
246 {
247 	return READ_ONCE(huge_zero_page) == page;
248 }
249 
250 static inline bool is_huge_zero_pmd(pmd_t pmd)
251 {
252 	return is_huge_zero_page(pmd_page(pmd));
253 }
254 
255 static inline bool is_huge_zero_pud(pud_t pud)
256 {
257 	return false;
258 }
259 
260 struct page *mm_get_huge_zero_page(struct mm_struct *mm);
261 void mm_put_huge_zero_page(struct mm_struct *mm);
262 
263 #define mk_huge_pmd(page, prot) pmd_mkhuge(mk_pmd(page, prot))
264 
265 static inline bool thp_migration_supported(void)
266 {
267 	return IS_ENABLED(CONFIG_ARCH_ENABLE_THP_MIGRATION);
268 }
269 
270 #else /* CONFIG_TRANSPARENT_HUGEPAGE */
271 #define HPAGE_PMD_SHIFT ({ BUILD_BUG(); 0; })
272 #define HPAGE_PMD_MASK ({ BUILD_BUG(); 0; })
273 #define HPAGE_PMD_SIZE ({ BUILD_BUG(); 0; })
274 
275 #define HPAGE_PUD_SHIFT ({ BUILD_BUG(); 0; })
276 #define HPAGE_PUD_MASK ({ BUILD_BUG(); 0; })
277 #define HPAGE_PUD_SIZE ({ BUILD_BUG(); 0; })
278 
279 #define hpage_nr_pages(x) 1
280 
281 static inline bool __transparent_hugepage_enabled(struct vm_area_struct *vma)
282 {
283 	return false;
284 }
285 
286 static inline bool transparent_hugepage_enabled(struct vm_area_struct *vma)
287 {
288 	return false;
289 }
290 
291 static inline bool transhuge_vma_suitable(struct vm_area_struct *vma,
292 		unsigned long haddr)
293 {
294 	return false;
295 }
296 
297 static inline void prep_transhuge_page(struct page *page) {}
298 
299 #define transparent_hugepage_flags 0UL
300 
301 #define thp_get_unmapped_area	NULL
302 
303 static inline bool
304 can_split_huge_page(struct page *page, int *pextra_pins)
305 {
306 	BUILD_BUG();
307 	return false;
308 }
309 static inline int
310 split_huge_page_to_list(struct page *page, struct list_head *list)
311 {
312 	return 0;
313 }
314 static inline int split_huge_page(struct page *page)
315 {
316 	return 0;
317 }
318 static inline void deferred_split_huge_page(struct page *page) {}
319 #define split_huge_pmd(__vma, __pmd, __address)	\
320 	do { } while (0)
321 
322 static inline void __split_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
323 		unsigned long address, bool freeze, struct page *page) {}
324 static inline void split_huge_pmd_address(struct vm_area_struct *vma,
325 		unsigned long address, bool freeze, struct page *page) {}
326 
327 #define split_huge_pud(__vma, __pmd, __address)	\
328 	do { } while (0)
329 
330 static inline int hugepage_madvise(struct vm_area_struct *vma,
331 				   unsigned long *vm_flags, int advice)
332 {
333 	BUG();
334 	return 0;
335 }
336 static inline void vma_adjust_trans_huge(struct vm_area_struct *vma,
337 					 unsigned long start,
338 					 unsigned long end,
339 					 long adjust_next)
340 {
341 }
342 static inline int is_swap_pmd(pmd_t pmd)
343 {
344 	return 0;
345 }
346 static inline spinlock_t *pmd_trans_huge_lock(pmd_t *pmd,
347 		struct vm_area_struct *vma)
348 {
349 	return NULL;
350 }
351 static inline spinlock_t *pud_trans_huge_lock(pud_t *pud,
352 		struct vm_area_struct *vma)
353 {
354 	return NULL;
355 }
356 
357 static inline vm_fault_t do_huge_pmd_numa_page(struct vm_fault *vmf,
358 		pmd_t orig_pmd)
359 {
360 	return 0;
361 }
362 
363 static inline bool is_huge_zero_page(struct page *page)
364 {
365 	return false;
366 }
367 
368 static inline bool is_huge_zero_pud(pud_t pud)
369 {
370 	return false;
371 }
372 
373 static inline void mm_put_huge_zero_page(struct mm_struct *mm)
374 {
375 	return;
376 }
377 
378 static inline struct page *follow_devmap_pmd(struct vm_area_struct *vma,
379 	unsigned long addr, pmd_t *pmd, int flags, struct dev_pagemap **pgmap)
380 {
381 	return NULL;
382 }
383 
384 static inline struct page *follow_devmap_pud(struct vm_area_struct *vma,
385 	unsigned long addr, pud_t *pud, int flags, struct dev_pagemap **pgmap)
386 {
387 	return NULL;
388 }
389 
390 static inline bool thp_migration_supported(void)
391 {
392 	return false;
393 }
394 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
395 
396 #endif /* _LINUX_HUGE_MM_H */
397