xref: /linux-6.15/include/linux/huge_mm.h (revision bb7e5ce7)
1 #ifndef _LINUX_HUGE_MM_H
2 #define _LINUX_HUGE_MM_H
3 
4 #include <linux/sched/coredump.h>
5 
6 #include <linux/fs.h> /* only for vma_is_dax() */
7 
8 extern int do_huge_pmd_anonymous_page(struct vm_fault *vmf);
9 extern int copy_huge_pmd(struct mm_struct *dst_mm, struct mm_struct *src_mm,
10 			 pmd_t *dst_pmd, pmd_t *src_pmd, unsigned long addr,
11 			 struct vm_area_struct *vma);
12 extern void huge_pmd_set_accessed(struct vm_fault *vmf, pmd_t orig_pmd);
13 extern int copy_huge_pud(struct mm_struct *dst_mm, struct mm_struct *src_mm,
14 			 pud_t *dst_pud, pud_t *src_pud, unsigned long addr,
15 			 struct vm_area_struct *vma);
16 
17 #ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
18 extern void huge_pud_set_accessed(struct vm_fault *vmf, pud_t orig_pud);
19 #else
20 static inline void huge_pud_set_accessed(struct vm_fault *vmf, pud_t orig_pud)
21 {
22 }
23 #endif
24 
25 extern int do_huge_pmd_wp_page(struct vm_fault *vmf, pmd_t orig_pmd);
26 extern struct page *follow_trans_huge_pmd(struct vm_area_struct *vma,
27 					  unsigned long addr,
28 					  pmd_t *pmd,
29 					  unsigned int flags);
30 extern bool madvise_free_huge_pmd(struct mmu_gather *tlb,
31 			struct vm_area_struct *vma,
32 			pmd_t *pmd, unsigned long addr, unsigned long next);
33 extern int zap_huge_pmd(struct mmu_gather *tlb,
34 			struct vm_area_struct *vma,
35 			pmd_t *pmd, unsigned long addr);
36 extern int zap_huge_pud(struct mmu_gather *tlb,
37 			struct vm_area_struct *vma,
38 			pud_t *pud, unsigned long addr);
39 extern int mincore_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
40 			unsigned long addr, unsigned long end,
41 			unsigned char *vec);
42 extern bool move_huge_pmd(struct vm_area_struct *vma, unsigned long old_addr,
43 			 unsigned long new_addr, unsigned long old_end,
44 			 pmd_t *old_pmd, pmd_t *new_pmd, bool *need_flush);
45 extern int change_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
46 			unsigned long addr, pgprot_t newprot,
47 			int prot_numa);
48 int vmf_insert_pfn_pmd(struct vm_area_struct *vma, unsigned long addr,
49 			pmd_t *pmd, pfn_t pfn, bool write);
50 int vmf_insert_pfn_pud(struct vm_area_struct *vma, unsigned long addr,
51 			pud_t *pud, 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 static inline bool transparent_hugepage_enabled(struct vm_area_struct *vma)
95 {
96 	if (vma->vm_flags & VM_NOHUGEPAGE)
97 		return false;
98 
99 	if (is_vma_temporary_stack(vma))
100 		return false;
101 
102 	if (test_bit(MMF_DISABLE_THP, &vma->vm_mm->flags))
103 		return false;
104 
105 	if (transparent_hugepage_flags & (1 << TRANSPARENT_HUGEPAGE_FLAG))
106 		return true;
107 
108 	if (vma_is_dax(vma))
109 		return true;
110 
111 	if (transparent_hugepage_flags &
112 				(1 << TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG))
113 		return !!(vma->vm_flags & VM_HUGEPAGE);
114 
115 	return false;
116 }
117 
118 #define transparent_hugepage_use_zero_page()				\
119 	(transparent_hugepage_flags &					\
120 	 (1<<TRANSPARENT_HUGEPAGE_USE_ZERO_PAGE_FLAG))
121 #ifdef CONFIG_DEBUG_VM
122 #define transparent_hugepage_debug_cow()				\
123 	(transparent_hugepage_flags &					\
124 	 (1<<TRANSPARENT_HUGEPAGE_DEBUG_COW_FLAG))
125 #else /* CONFIG_DEBUG_VM */
126 #define transparent_hugepage_debug_cow() 0
127 #endif /* CONFIG_DEBUG_VM */
128 
129 extern unsigned long thp_get_unmapped_area(struct file *filp,
130 		unsigned long addr, unsigned long len, unsigned long pgoff,
131 		unsigned long flags);
132 
133 extern void prep_transhuge_page(struct page *page);
134 extern void free_transhuge_page(struct page *page);
135 
136 bool can_split_huge_page(struct page *page, int *pextra_pins);
137 int split_huge_page_to_list(struct page *page, struct list_head *list);
138 static inline int split_huge_page(struct page *page)
139 {
140 	return split_huge_page_to_list(page, NULL);
141 }
142 void deferred_split_huge_page(struct page *page);
143 
144 void __split_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
145 		unsigned long address, bool freeze, struct page *page);
146 
147 #define split_huge_pmd(__vma, __pmd, __address)				\
148 	do {								\
149 		pmd_t *____pmd = (__pmd);				\
150 		if (is_swap_pmd(*____pmd) || pmd_trans_huge(*____pmd)	\
151 					|| pmd_devmap(*____pmd))	\
152 			__split_huge_pmd(__vma, __pmd, __address,	\
153 						false, NULL);		\
154 	}  while (0)
155 
156 
157 void split_huge_pmd_address(struct vm_area_struct *vma, unsigned long address,
158 		bool freeze, struct page *page);
159 
160 void __split_huge_pud(struct vm_area_struct *vma, pud_t *pud,
161 		unsigned long address);
162 
163 #define split_huge_pud(__vma, __pud, __address)				\
164 	do {								\
165 		pud_t *____pud = (__pud);				\
166 		if (pud_trans_huge(*____pud)				\
167 					|| pud_devmap(*____pud))	\
168 			__split_huge_pud(__vma, __pud, __address);	\
169 	}  while (0)
170 
171 extern int hugepage_madvise(struct vm_area_struct *vma,
172 			    unsigned long *vm_flags, int advice);
173 extern void vma_adjust_trans_huge(struct vm_area_struct *vma,
174 				    unsigned long start,
175 				    unsigned long end,
176 				    long adjust_next);
177 extern spinlock_t *__pmd_trans_huge_lock(pmd_t *pmd,
178 		struct vm_area_struct *vma);
179 extern spinlock_t *__pud_trans_huge_lock(pud_t *pud,
180 		struct vm_area_struct *vma);
181 
182 static inline int is_swap_pmd(pmd_t pmd)
183 {
184 	return !pmd_none(pmd) && !pmd_present(pmd);
185 }
186 
187 /* mmap_sem must be held on entry */
188 static inline spinlock_t *pmd_trans_huge_lock(pmd_t *pmd,
189 		struct vm_area_struct *vma)
190 {
191 	VM_BUG_ON_VMA(!rwsem_is_locked(&vma->vm_mm->mmap_sem), vma);
192 	if (is_swap_pmd(*pmd) || pmd_trans_huge(*pmd) || pmd_devmap(*pmd))
193 		return __pmd_trans_huge_lock(pmd, vma);
194 	else
195 		return NULL;
196 }
197 static inline spinlock_t *pud_trans_huge_lock(pud_t *pud,
198 		struct vm_area_struct *vma)
199 {
200 	VM_BUG_ON_VMA(!rwsem_is_locked(&vma->vm_mm->mmap_sem), vma);
201 	if (pud_trans_huge(*pud) || pud_devmap(*pud))
202 		return __pud_trans_huge_lock(pud, vma);
203 	else
204 		return NULL;
205 }
206 static inline int hpage_nr_pages(struct page *page)
207 {
208 	if (unlikely(PageTransHuge(page)))
209 		return HPAGE_PMD_NR;
210 	return 1;
211 }
212 
213 struct page *follow_devmap_pmd(struct vm_area_struct *vma, unsigned long addr,
214 		pmd_t *pmd, int flags);
215 struct page *follow_devmap_pud(struct vm_area_struct *vma, unsigned long addr,
216 		pud_t *pud, int flags);
217 
218 extern int do_huge_pmd_numa_page(struct vm_fault *vmf, pmd_t orig_pmd);
219 
220 extern struct page *huge_zero_page;
221 
222 static inline bool is_huge_zero_page(struct page *page)
223 {
224 	return ACCESS_ONCE(huge_zero_page) == page;
225 }
226 
227 static inline bool is_huge_zero_pmd(pmd_t pmd)
228 {
229 	return is_huge_zero_page(pmd_page(pmd));
230 }
231 
232 static inline bool is_huge_zero_pud(pud_t pud)
233 {
234 	return false;
235 }
236 
237 struct page *mm_get_huge_zero_page(struct mm_struct *mm);
238 void mm_put_huge_zero_page(struct mm_struct *mm);
239 
240 #define mk_huge_pmd(page, prot) pmd_mkhuge(mk_pmd(page, prot))
241 
242 static inline bool thp_migration_supported(void)
243 {
244 	return IS_ENABLED(CONFIG_ARCH_ENABLE_THP_MIGRATION);
245 }
246 
247 #else /* CONFIG_TRANSPARENT_HUGEPAGE */
248 #define HPAGE_PMD_SHIFT ({ BUILD_BUG(); 0; })
249 #define HPAGE_PMD_MASK ({ BUILD_BUG(); 0; })
250 #define HPAGE_PMD_SIZE ({ BUILD_BUG(); 0; })
251 
252 #define HPAGE_PUD_SHIFT ({ BUILD_BUG(); 0; })
253 #define HPAGE_PUD_MASK ({ BUILD_BUG(); 0; })
254 #define HPAGE_PUD_SIZE ({ BUILD_BUG(); 0; })
255 
256 #define hpage_nr_pages(x) 1
257 
258 static inline bool transparent_hugepage_enabled(struct vm_area_struct *vma)
259 {
260 	return false;
261 }
262 
263 static inline void prep_transhuge_page(struct page *page) {}
264 
265 #define transparent_hugepage_flags 0UL
266 
267 #define thp_get_unmapped_area	NULL
268 
269 static inline bool
270 can_split_huge_page(struct page *page, int *pextra_pins)
271 {
272 	BUILD_BUG();
273 	return false;
274 }
275 static inline int
276 split_huge_page_to_list(struct page *page, struct list_head *list)
277 {
278 	return 0;
279 }
280 static inline int split_huge_page(struct page *page)
281 {
282 	return 0;
283 }
284 static inline void deferred_split_huge_page(struct page *page) {}
285 #define split_huge_pmd(__vma, __pmd, __address)	\
286 	do { } while (0)
287 
288 static inline void __split_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
289 		unsigned long address, bool freeze, struct page *page) {}
290 static inline void split_huge_pmd_address(struct vm_area_struct *vma,
291 		unsigned long address, bool freeze, struct page *page) {}
292 
293 #define split_huge_pud(__vma, __pmd, __address)	\
294 	do { } while (0)
295 
296 static inline int hugepage_madvise(struct vm_area_struct *vma,
297 				   unsigned long *vm_flags, int advice)
298 {
299 	BUG();
300 	return 0;
301 }
302 static inline void vma_adjust_trans_huge(struct vm_area_struct *vma,
303 					 unsigned long start,
304 					 unsigned long end,
305 					 long adjust_next)
306 {
307 }
308 static inline int is_swap_pmd(pmd_t pmd)
309 {
310 	return 0;
311 }
312 static inline spinlock_t *pmd_trans_huge_lock(pmd_t *pmd,
313 		struct vm_area_struct *vma)
314 {
315 	return NULL;
316 }
317 static inline spinlock_t *pud_trans_huge_lock(pud_t *pud,
318 		struct vm_area_struct *vma)
319 {
320 	return NULL;
321 }
322 
323 static inline int do_huge_pmd_numa_page(struct vm_fault *vmf, pmd_t orig_pmd)
324 {
325 	return 0;
326 }
327 
328 static inline bool is_huge_zero_page(struct page *page)
329 {
330 	return false;
331 }
332 
333 static inline bool is_huge_zero_pud(pud_t pud)
334 {
335 	return false;
336 }
337 
338 static inline void mm_put_huge_zero_page(struct mm_struct *mm)
339 {
340 	return;
341 }
342 
343 static inline struct page *follow_devmap_pmd(struct vm_area_struct *vma,
344 		unsigned long addr, pmd_t *pmd, int flags)
345 {
346 	return NULL;
347 }
348 
349 static inline struct page *follow_devmap_pud(struct vm_area_struct *vma,
350 		unsigned long addr, pud_t *pud, int flags)
351 {
352 	return NULL;
353 }
354 
355 static inline bool thp_migration_supported(void)
356 {
357 	return false;
358 }
359 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
360 
361 #endif /* _LINUX_HUGE_MM_H */
362