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
huge_pud_set_accessed(struct vm_fault * vmf,pud_t orig_pud)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  */
__transparent_hugepage_enabled(struct vm_area_struct * vma)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 transparent_hugepage_use_zero_page()				\
125 	(transparent_hugepage_flags &					\
126 	 (1<<TRANSPARENT_HUGEPAGE_USE_ZERO_PAGE_FLAG))
127 #ifdef CONFIG_DEBUG_VM
128 #define transparent_hugepage_debug_cow()				\
129 	(transparent_hugepage_flags &					\
130 	 (1<<TRANSPARENT_HUGEPAGE_DEBUG_COW_FLAG))
131 #else /* CONFIG_DEBUG_VM */
132 #define transparent_hugepage_debug_cow() 0
133 #endif /* CONFIG_DEBUG_VM */
134 
135 extern unsigned long thp_get_unmapped_area(struct file *filp,
136 		unsigned long addr, unsigned long len, unsigned long pgoff,
137 		unsigned long flags);
138 
139 extern void prep_transhuge_page(struct page *page);
140 extern void free_transhuge_page(struct page *page);
141 
142 bool can_split_huge_page(struct page *page, int *pextra_pins);
143 int split_huge_page_to_list(struct page *page, struct list_head *list);
split_huge_page(struct page * page)144 static inline int split_huge_page(struct page *page)
145 {
146 	return split_huge_page_to_list(page, NULL);
147 }
148 void deferred_split_huge_page(struct page *page);
149 
150 void __split_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
151 		unsigned long address, bool freeze, struct page *page);
152 
153 #define split_huge_pmd(__vma, __pmd, __address)				\
154 	do {								\
155 		pmd_t *____pmd = (__pmd);				\
156 		if (is_swap_pmd(*____pmd) || pmd_trans_huge(*____pmd)	\
157 					|| pmd_devmap(*____pmd))	\
158 			__split_huge_pmd(__vma, __pmd, __address,	\
159 						false, NULL);		\
160 	}  while (0)
161 
162 
163 void split_huge_pmd_address(struct vm_area_struct *vma, unsigned long address,
164 		bool freeze, struct page *page);
165 
166 void __split_huge_pud(struct vm_area_struct *vma, pud_t *pud,
167 		unsigned long address);
168 
169 #define split_huge_pud(__vma, __pud, __address)				\
170 	do {								\
171 		pud_t *____pud = (__pud);				\
172 		if (pud_trans_huge(*____pud)				\
173 					|| pud_devmap(*____pud))	\
174 			__split_huge_pud(__vma, __pud, __address);	\
175 	}  while (0)
176 
177 extern int hugepage_madvise(struct vm_area_struct *vma,
178 			    unsigned long *vm_flags, int advice);
179 extern void vma_adjust_trans_huge(struct vm_area_struct *vma,
180 				    unsigned long start,
181 				    unsigned long end,
182 				    long adjust_next);
183 extern spinlock_t *__pmd_trans_huge_lock(pmd_t *pmd,
184 		struct vm_area_struct *vma);
185 extern spinlock_t *__pud_trans_huge_lock(pud_t *pud,
186 		struct vm_area_struct *vma);
187 
is_swap_pmd(pmd_t pmd)188 static inline int is_swap_pmd(pmd_t pmd)
189 {
190 	return !pmd_none(pmd) && !pmd_present(pmd);
191 }
192 
193 /* mmap_sem must be held on entry */
pmd_trans_huge_lock(pmd_t * pmd,struct vm_area_struct * vma)194 static inline spinlock_t *pmd_trans_huge_lock(pmd_t *pmd,
195 		struct vm_area_struct *vma)
196 {
197 	VM_BUG_ON_VMA(!rwsem_is_locked(&vma->vm_mm->mmap_sem), vma);
198 	if (is_swap_pmd(*pmd) || pmd_trans_huge(*pmd) || pmd_devmap(*pmd))
199 		return __pmd_trans_huge_lock(pmd, vma);
200 	else
201 		return NULL;
202 }
pud_trans_huge_lock(pud_t * pud,struct vm_area_struct * vma)203 static inline spinlock_t *pud_trans_huge_lock(pud_t *pud,
204 		struct vm_area_struct *vma)
205 {
206 	VM_BUG_ON_VMA(!rwsem_is_locked(&vma->vm_mm->mmap_sem), vma);
207 	if (pud_trans_huge(*pud) || pud_devmap(*pud))
208 		return __pud_trans_huge_lock(pud, vma);
209 	else
210 		return NULL;
211 }
hpage_nr_pages(struct page * page)212 static inline int hpage_nr_pages(struct page *page)
213 {
214 	if (unlikely(PageTransHuge(page)))
215 		return HPAGE_PMD_NR;
216 	return 1;
217 }
218 
219 struct page *follow_devmap_pmd(struct vm_area_struct *vma, unsigned long addr,
220 		pmd_t *pmd, int flags);
221 struct page *follow_devmap_pud(struct vm_area_struct *vma, unsigned long addr,
222 		pud_t *pud, int flags);
223 
224 extern vm_fault_t do_huge_pmd_numa_page(struct vm_fault *vmf, pmd_t orig_pmd);
225 
226 extern struct page *huge_zero_page;
227 extern unsigned long huge_zero_pfn;
228 
is_huge_zero_page(struct page * page)229 static inline bool is_huge_zero_page(struct page *page)
230 {
231 	return READ_ONCE(huge_zero_page) == page;
232 }
233 
is_huge_zero_pmd(pmd_t pmd)234 static inline bool is_huge_zero_pmd(pmd_t pmd)
235 {
236 	return READ_ONCE(huge_zero_pfn) == pmd_pfn(pmd) && pmd_present(pmd);
237 }
238 
is_huge_zero_pud(pud_t pud)239 static inline bool is_huge_zero_pud(pud_t pud)
240 {
241 	return false;
242 }
243 
244 struct page *mm_get_huge_zero_page(struct mm_struct *mm);
245 void mm_put_huge_zero_page(struct mm_struct *mm);
246 
247 #define mk_huge_pmd(page, prot) pmd_mkhuge(mk_pmd(page, prot))
248 
thp_migration_supported(void)249 static inline bool thp_migration_supported(void)
250 {
251 	return IS_ENABLED(CONFIG_ARCH_ENABLE_THP_MIGRATION);
252 }
253 
254 #else /* CONFIG_TRANSPARENT_HUGEPAGE */
255 #define HPAGE_PMD_SHIFT ({ BUILD_BUG(); 0; })
256 #define HPAGE_PMD_MASK ({ BUILD_BUG(); 0; })
257 #define HPAGE_PMD_SIZE ({ BUILD_BUG(); 0; })
258 
259 #define HPAGE_PUD_SHIFT ({ BUILD_BUG(); 0; })
260 #define HPAGE_PUD_MASK ({ BUILD_BUG(); 0; })
261 #define HPAGE_PUD_SIZE ({ BUILD_BUG(); 0; })
262 
263 #define hpage_nr_pages(x) 1
264 
__transparent_hugepage_enabled(struct vm_area_struct * vma)265 static inline bool __transparent_hugepage_enabled(struct vm_area_struct *vma)
266 {
267 	return false;
268 }
269 
transparent_hugepage_enabled(struct vm_area_struct * vma)270 static inline bool transparent_hugepage_enabled(struct vm_area_struct *vma)
271 {
272 	return false;
273 }
274 
prep_transhuge_page(struct page * page)275 static inline void prep_transhuge_page(struct page *page) {}
276 
277 #define transparent_hugepage_flags 0UL
278 
279 #define thp_get_unmapped_area	NULL
280 
281 static inline bool
can_split_huge_page(struct page * page,int * pextra_pins)282 can_split_huge_page(struct page *page, int *pextra_pins)
283 {
284 	BUILD_BUG();
285 	return false;
286 }
287 static inline int
split_huge_page_to_list(struct page * page,struct list_head * list)288 split_huge_page_to_list(struct page *page, struct list_head *list)
289 {
290 	return 0;
291 }
split_huge_page(struct page * page)292 static inline int split_huge_page(struct page *page)
293 {
294 	return 0;
295 }
deferred_split_huge_page(struct page * page)296 static inline void deferred_split_huge_page(struct page *page) {}
297 #define split_huge_pmd(__vma, __pmd, __address)	\
298 	do { } while (0)
299 
__split_huge_pmd(struct vm_area_struct * vma,pmd_t * pmd,unsigned long address,bool freeze,struct page * page)300 static inline void __split_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
301 		unsigned long address, bool freeze, struct page *page) {}
split_huge_pmd_address(struct vm_area_struct * vma,unsigned long address,bool freeze,struct page * page)302 static inline void split_huge_pmd_address(struct vm_area_struct *vma,
303 		unsigned long address, bool freeze, struct page *page) {}
304 
305 #define split_huge_pud(__vma, __pmd, __address)	\
306 	do { } while (0)
307 
hugepage_madvise(struct vm_area_struct * vma,unsigned long * vm_flags,int advice)308 static inline int hugepage_madvise(struct vm_area_struct *vma,
309 				   unsigned long *vm_flags, int advice)
310 {
311 	BUG();
312 	return 0;
313 }
vma_adjust_trans_huge(struct vm_area_struct * vma,unsigned long start,unsigned long end,long adjust_next)314 static inline void vma_adjust_trans_huge(struct vm_area_struct *vma,
315 					 unsigned long start,
316 					 unsigned long end,
317 					 long adjust_next)
318 {
319 }
is_swap_pmd(pmd_t pmd)320 static inline int is_swap_pmd(pmd_t pmd)
321 {
322 	return 0;
323 }
pmd_trans_huge_lock(pmd_t * pmd,struct vm_area_struct * vma)324 static inline spinlock_t *pmd_trans_huge_lock(pmd_t *pmd,
325 		struct vm_area_struct *vma)
326 {
327 	return NULL;
328 }
pud_trans_huge_lock(pud_t * pud,struct vm_area_struct * vma)329 static inline spinlock_t *pud_trans_huge_lock(pud_t *pud,
330 		struct vm_area_struct *vma)
331 {
332 	return NULL;
333 }
334 
do_huge_pmd_numa_page(struct vm_fault * vmf,pmd_t orig_pmd)335 static inline vm_fault_t do_huge_pmd_numa_page(struct vm_fault *vmf,
336 		pmd_t orig_pmd)
337 {
338 	return 0;
339 }
340 
is_huge_zero_page(struct page * page)341 static inline bool is_huge_zero_page(struct page *page)
342 {
343 	return false;
344 }
345 
is_huge_zero_pmd(pmd_t pmd)346 static inline bool is_huge_zero_pmd(pmd_t pmd)
347 {
348 	return false;
349 }
350 
is_huge_zero_pud(pud_t pud)351 static inline bool is_huge_zero_pud(pud_t pud)
352 {
353 	return false;
354 }
355 
mm_put_huge_zero_page(struct mm_struct * mm)356 static inline void mm_put_huge_zero_page(struct mm_struct *mm)
357 {
358 	return;
359 }
360 
follow_devmap_pmd(struct vm_area_struct * vma,unsigned long addr,pmd_t * pmd,int flags)361 static inline struct page *follow_devmap_pmd(struct vm_area_struct *vma,
362 		unsigned long addr, pmd_t *pmd, int flags)
363 {
364 	return NULL;
365 }
366 
follow_devmap_pud(struct vm_area_struct * vma,unsigned long addr,pud_t * pud,int flags)367 static inline struct page *follow_devmap_pud(struct vm_area_struct *vma,
368 		unsigned long addr, pud_t *pud, int flags)
369 {
370 	return NULL;
371 }
372 
thp_migration_supported(void)373 static inline bool thp_migration_supported(void)
374 {
375 	return false;
376 }
377 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
378 
379 #endif /* _LINUX_HUGE_MM_H */
380