xref: /linux-6.15/include/linux/huge_mm.h (revision 6b8abef5)
1 #ifndef _LINUX_HUGE_MM_H
2 #define _LINUX_HUGE_MM_H
3 
4 extern int do_huge_pmd_anonymous_page(struct mm_struct *mm,
5 				      struct vm_area_struct *vma,
6 				      unsigned long address, pmd_t *pmd,
7 				      unsigned int flags);
8 extern int copy_huge_pmd(struct mm_struct *dst_mm, struct mm_struct *src_mm,
9 			 pmd_t *dst_pmd, pmd_t *src_pmd, unsigned long addr,
10 			 struct vm_area_struct *vma);
11 extern void huge_pmd_set_accessed(struct mm_struct *mm,
12 				  struct vm_area_struct *vma,
13 				  unsigned long address, pmd_t *pmd,
14 				  pmd_t orig_pmd, int dirty);
15 extern int do_huge_pmd_wp_page(struct mm_struct *mm, struct vm_area_struct *vma,
16 			       unsigned long address, pmd_t *pmd,
17 			       pmd_t orig_pmd);
18 extern struct page *follow_trans_huge_pmd(struct vm_area_struct *vma,
19 					  unsigned long addr,
20 					  pmd_t *pmd,
21 					  unsigned int flags);
22 extern int madvise_free_huge_pmd(struct mmu_gather *tlb,
23 			struct vm_area_struct *vma,
24 			pmd_t *pmd, unsigned long addr, unsigned long next);
25 extern int zap_huge_pmd(struct mmu_gather *tlb,
26 			struct vm_area_struct *vma,
27 			pmd_t *pmd, unsigned long addr);
28 extern int mincore_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
29 			unsigned long addr, unsigned long end,
30 			unsigned char *vec);
31 extern bool move_huge_pmd(struct vm_area_struct *vma,
32 			 struct vm_area_struct *new_vma,
33 			 unsigned long old_addr,
34 			 unsigned long new_addr, unsigned long old_end,
35 			 pmd_t *old_pmd, pmd_t *new_pmd);
36 extern int change_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
37 			unsigned long addr, pgprot_t newprot,
38 			int prot_numa);
39 int vmf_insert_pfn_pmd(struct vm_area_struct *, unsigned long addr, pmd_t *,
40 			pfn_t pfn, bool write);
41 enum transparent_hugepage_flag {
42 	TRANSPARENT_HUGEPAGE_FLAG,
43 	TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG,
44 	TRANSPARENT_HUGEPAGE_DEFRAG_FLAG,
45 	TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG,
46 	TRANSPARENT_HUGEPAGE_DEFRAG_KHUGEPAGED_FLAG,
47 	TRANSPARENT_HUGEPAGE_USE_ZERO_PAGE_FLAG,
48 #ifdef CONFIG_DEBUG_VM
49 	TRANSPARENT_HUGEPAGE_DEBUG_COW_FLAG,
50 #endif
51 };
52 
53 #define HPAGE_PMD_ORDER (HPAGE_PMD_SHIFT-PAGE_SHIFT)
54 #define HPAGE_PMD_NR (1<<HPAGE_PMD_ORDER)
55 
56 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
57 struct page *follow_devmap_pmd(struct vm_area_struct *vma, unsigned long addr,
58 		pmd_t *pmd, int flags);
59 
60 #define HPAGE_PMD_SHIFT PMD_SHIFT
61 #define HPAGE_PMD_SIZE	((1UL) << HPAGE_PMD_SHIFT)
62 #define HPAGE_PMD_MASK	(~(HPAGE_PMD_SIZE - 1))
63 
64 extern bool is_vma_temporary_stack(struct vm_area_struct *vma);
65 
66 #define transparent_hugepage_enabled(__vma)				\
67 	((transparent_hugepage_flags &					\
68 	  (1<<TRANSPARENT_HUGEPAGE_FLAG) ||				\
69 	  (transparent_hugepage_flags &					\
70 	   (1<<TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG) &&			\
71 	   ((__vma)->vm_flags & VM_HUGEPAGE))) &&			\
72 	 !((__vma)->vm_flags & VM_NOHUGEPAGE) &&			\
73 	 !is_vma_temporary_stack(__vma))
74 #define transparent_hugepage_defrag(__vma)				\
75 	((transparent_hugepage_flags &					\
76 	  (1<<TRANSPARENT_HUGEPAGE_DEFRAG_FLAG)) ||			\
77 	 (transparent_hugepage_flags &					\
78 	  (1<<TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG) &&		\
79 	  (__vma)->vm_flags & VM_HUGEPAGE))
80 #define transparent_hugepage_use_zero_page()				\
81 	(transparent_hugepage_flags &					\
82 	 (1<<TRANSPARENT_HUGEPAGE_USE_ZERO_PAGE_FLAG))
83 #ifdef CONFIG_DEBUG_VM
84 #define transparent_hugepage_debug_cow()				\
85 	(transparent_hugepage_flags &					\
86 	 (1<<TRANSPARENT_HUGEPAGE_DEBUG_COW_FLAG))
87 #else /* CONFIG_DEBUG_VM */
88 #define transparent_hugepage_debug_cow() 0
89 #endif /* CONFIG_DEBUG_VM */
90 
91 extern unsigned long transparent_hugepage_flags;
92 
93 extern void prep_transhuge_page(struct page *page);
94 extern void free_transhuge_page(struct page *page);
95 
96 int split_huge_page_to_list(struct page *page, struct list_head *list);
97 static inline int split_huge_page(struct page *page)
98 {
99 	return split_huge_page_to_list(page, NULL);
100 }
101 void deferred_split_huge_page(struct page *page);
102 
103 void __split_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
104 		unsigned long address);
105 
106 #define split_huge_pmd(__vma, __pmd, __address)				\
107 	do {								\
108 		pmd_t *____pmd = (__pmd);				\
109 		if (pmd_trans_huge(*____pmd)				\
110 					|| pmd_devmap(*____pmd))	\
111 			__split_huge_pmd(__vma, __pmd, __address);	\
112 	}  while (0)
113 
114 #if HPAGE_PMD_ORDER >= MAX_ORDER
115 #error "hugepages can't be allocated by the buddy allocator"
116 #endif
117 extern int hugepage_madvise(struct vm_area_struct *vma,
118 			    unsigned long *vm_flags, int advice);
119 extern void vma_adjust_trans_huge(struct vm_area_struct *vma,
120 				    unsigned long start,
121 				    unsigned long end,
122 				    long adjust_next);
123 extern spinlock_t *__pmd_trans_huge_lock(pmd_t *pmd,
124 		struct vm_area_struct *vma);
125 /* mmap_sem must be held on entry */
126 static inline spinlock_t *pmd_trans_huge_lock(pmd_t *pmd,
127 		struct vm_area_struct *vma)
128 {
129 	VM_BUG_ON_VMA(!rwsem_is_locked(&vma->vm_mm->mmap_sem), vma);
130 	if (pmd_trans_huge(*pmd) || pmd_devmap(*pmd))
131 		return __pmd_trans_huge_lock(pmd, vma);
132 	else
133 		return false;
134 }
135 static inline int hpage_nr_pages(struct page *page)
136 {
137 	if (unlikely(PageTransHuge(page)))
138 		return HPAGE_PMD_NR;
139 	return 1;
140 }
141 
142 extern int do_huge_pmd_numa_page(struct mm_struct *mm, struct vm_area_struct *vma,
143 				unsigned long addr, pmd_t pmd, pmd_t *pmdp);
144 
145 extern struct page *huge_zero_page;
146 
147 static inline bool is_huge_zero_page(struct page *page)
148 {
149 	return ACCESS_ONCE(huge_zero_page) == page;
150 }
151 
152 static inline bool is_huge_zero_pmd(pmd_t pmd)
153 {
154 	return is_huge_zero_page(pmd_page(pmd));
155 }
156 
157 struct page *get_huge_zero_page(void);
158 
159 #else /* CONFIG_TRANSPARENT_HUGEPAGE */
160 #define HPAGE_PMD_SHIFT ({ BUILD_BUG(); 0; })
161 #define HPAGE_PMD_MASK ({ BUILD_BUG(); 0; })
162 #define HPAGE_PMD_SIZE ({ BUILD_BUG(); 0; })
163 
164 #define hpage_nr_pages(x) 1
165 
166 #define transparent_hugepage_enabled(__vma) 0
167 
168 #define transparent_hugepage_flags 0UL
169 static inline int
170 split_huge_page_to_list(struct page *page, struct list_head *list)
171 {
172 	return 0;
173 }
174 static inline int split_huge_page(struct page *page)
175 {
176 	return 0;
177 }
178 static inline void deferred_split_huge_page(struct page *page) {}
179 #define split_huge_pmd(__vma, __pmd, __address)	\
180 	do { } while (0)
181 static inline int hugepage_madvise(struct vm_area_struct *vma,
182 				   unsigned long *vm_flags, int advice)
183 {
184 	BUG();
185 	return 0;
186 }
187 static inline void vma_adjust_trans_huge(struct vm_area_struct *vma,
188 					 unsigned long start,
189 					 unsigned long end,
190 					 long adjust_next)
191 {
192 }
193 static inline spinlock_t *pmd_trans_huge_lock(pmd_t *pmd,
194 		struct vm_area_struct *vma)
195 {
196 	return NULL;
197 }
198 
199 static inline int do_huge_pmd_numa_page(struct mm_struct *mm, struct vm_area_struct *vma,
200 					unsigned long addr, pmd_t pmd, pmd_t *pmdp)
201 {
202 	return 0;
203 }
204 
205 static inline bool is_huge_zero_page(struct page *page)
206 {
207 	return false;
208 }
209 
210 
211 static inline struct page *follow_devmap_pmd(struct vm_area_struct *vma,
212 		unsigned long addr, pmd_t *pmd, int flags)
213 {
214 	return NULL;
215 }
216 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
217 
218 #endif /* _LINUX_HUGE_MM_H */
219