xref: /linux-6.15/include/linux/huge_mm.h (revision a22b8f4b)
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 zap_huge_pmd(struct mmu_gather *tlb,
23 			struct vm_area_struct *vma,
24 			pmd_t *pmd, unsigned long addr);
25 extern int mincore_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
26 			unsigned long addr, unsigned long end,
27 			unsigned char *vec);
28 extern int move_huge_pmd(struct vm_area_struct *vma,
29 			 struct vm_area_struct *new_vma,
30 			 unsigned long old_addr,
31 			 unsigned long new_addr, unsigned long old_end,
32 			 pmd_t *old_pmd, pmd_t *new_pmd);
33 extern int change_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
34 			unsigned long addr, pgprot_t newprot,
35 			int prot_numa);
36 
37 enum transparent_hugepage_flag {
38 	TRANSPARENT_HUGEPAGE_FLAG,
39 	TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG,
40 	TRANSPARENT_HUGEPAGE_DEFRAG_FLAG,
41 	TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG,
42 	TRANSPARENT_HUGEPAGE_DEFRAG_KHUGEPAGED_FLAG,
43 	TRANSPARENT_HUGEPAGE_USE_ZERO_PAGE_FLAG,
44 #ifdef CONFIG_DEBUG_VM
45 	TRANSPARENT_HUGEPAGE_DEBUG_COW_FLAG,
46 #endif
47 };
48 
49 enum page_check_address_pmd_flag {
50 	PAGE_CHECK_ADDRESS_PMD_FLAG,
51 	PAGE_CHECK_ADDRESS_PMD_NOTSPLITTING_FLAG,
52 	PAGE_CHECK_ADDRESS_PMD_SPLITTING_FLAG,
53 };
54 extern pmd_t *page_check_address_pmd(struct page *page,
55 				     struct mm_struct *mm,
56 				     unsigned long address,
57 				     enum page_check_address_pmd_flag flag);
58 
59 #define HPAGE_PMD_ORDER (HPAGE_PMD_SHIFT-PAGE_SHIFT)
60 #define HPAGE_PMD_NR (1<<HPAGE_PMD_ORDER)
61 
62 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
63 #define HPAGE_PMD_SHIFT PMD_SHIFT
64 #define HPAGE_PMD_SIZE	((1UL) << HPAGE_PMD_SHIFT)
65 #define HPAGE_PMD_MASK	(~(HPAGE_PMD_SIZE - 1))
66 
67 extern bool is_vma_temporary_stack(struct vm_area_struct *vma);
68 
69 #define transparent_hugepage_enabled(__vma)				\
70 	((transparent_hugepage_flags &					\
71 	  (1<<TRANSPARENT_HUGEPAGE_FLAG) ||				\
72 	  (transparent_hugepage_flags &					\
73 	   (1<<TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG) &&			\
74 	   ((__vma)->vm_flags & VM_HUGEPAGE))) &&			\
75 	 !((__vma)->vm_flags & VM_NOHUGEPAGE) &&			\
76 	 !is_vma_temporary_stack(__vma))
77 #define transparent_hugepage_defrag(__vma)				\
78 	((transparent_hugepage_flags &					\
79 	  (1<<TRANSPARENT_HUGEPAGE_DEFRAG_FLAG)) ||			\
80 	 (transparent_hugepage_flags &					\
81 	  (1<<TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG) &&		\
82 	  (__vma)->vm_flags & VM_HUGEPAGE))
83 #define transparent_hugepage_use_zero_page()				\
84 	(transparent_hugepage_flags &					\
85 	 (1<<TRANSPARENT_HUGEPAGE_USE_ZERO_PAGE_FLAG))
86 #ifdef CONFIG_DEBUG_VM
87 #define transparent_hugepage_debug_cow()				\
88 	(transparent_hugepage_flags &					\
89 	 (1<<TRANSPARENT_HUGEPAGE_DEBUG_COW_FLAG))
90 #else /* CONFIG_DEBUG_VM */
91 #define transparent_hugepage_debug_cow() 0
92 #endif /* CONFIG_DEBUG_VM */
93 
94 extern unsigned long transparent_hugepage_flags;
95 extern int copy_pte_range(struct mm_struct *dst_mm, struct mm_struct *src_mm,
96 			  pmd_t *dst_pmd, pmd_t *src_pmd,
97 			  struct vm_area_struct *vma,
98 			  unsigned long addr, unsigned long end);
99 extern int split_huge_page_to_list(struct page *page, struct list_head *list);
100 static inline int split_huge_page(struct page *page)
101 {
102 	return split_huge_page_to_list(page, NULL);
103 }
104 extern void __split_huge_page_pmd(struct vm_area_struct *vma,
105 		unsigned long address, pmd_t *pmd);
106 #define split_huge_page_pmd(__vma, __address, __pmd)			\
107 	do {								\
108 		pmd_t *____pmd = (__pmd);				\
109 		if (unlikely(pmd_trans_huge(*____pmd)))			\
110 			__split_huge_page_pmd(__vma, __address,		\
111 					____pmd);			\
112 	}  while (0)
113 #define wait_split_huge_page(__anon_vma, __pmd)				\
114 	do {								\
115 		pmd_t *____pmd = (__pmd);				\
116 		anon_vma_lock_write(__anon_vma);			\
117 		anon_vma_unlock_write(__anon_vma);			\
118 		BUG_ON(pmd_trans_splitting(*____pmd) ||			\
119 		       pmd_trans_huge(*____pmd));			\
120 	} while (0)
121 extern void split_huge_page_pmd_mm(struct mm_struct *mm, unsigned long address,
122 		pmd_t *pmd);
123 #if HPAGE_PMD_ORDER >= MAX_ORDER
124 #error "hugepages can't be allocated by the buddy allocator"
125 #endif
126 extern int hugepage_madvise(struct vm_area_struct *vma,
127 			    unsigned long *vm_flags, int advice);
128 extern void __vma_adjust_trans_huge(struct vm_area_struct *vma,
129 				    unsigned long start,
130 				    unsigned long end,
131 				    long adjust_next);
132 extern int __pmd_trans_huge_lock(pmd_t *pmd,
133 				 struct vm_area_struct *vma);
134 /* mmap_sem must be held on entry */
135 static inline int pmd_trans_huge_lock(pmd_t *pmd,
136 				      struct vm_area_struct *vma)
137 {
138 	VM_BUG_ON(!rwsem_is_locked(&vma->vm_mm->mmap_sem));
139 	if (pmd_trans_huge(*pmd))
140 		return __pmd_trans_huge_lock(pmd, vma);
141 	else
142 		return 0;
143 }
144 static inline void vma_adjust_trans_huge(struct vm_area_struct *vma,
145 					 unsigned long start,
146 					 unsigned long end,
147 					 long adjust_next)
148 {
149 	if (!vma->anon_vma || vma->vm_ops)
150 		return;
151 	__vma_adjust_trans_huge(vma, start, end, adjust_next);
152 }
153 static inline int hpage_nr_pages(struct page *page)
154 {
155 	if (unlikely(PageTransHuge(page)))
156 		return HPAGE_PMD_NR;
157 	return 1;
158 }
159 static inline struct page *compound_trans_head(struct page *page)
160 {
161 	if (PageTail(page)) {
162 		struct page *head;
163 		head = page->first_page;
164 		smp_rmb();
165 		/*
166 		 * head may be a dangling pointer.
167 		 * __split_huge_page_refcount clears PageTail before
168 		 * overwriting first_page, so if PageTail is still
169 		 * there it means the head pointer isn't dangling.
170 		 */
171 		if (PageTail(page))
172 			return head;
173 	}
174 	return page;
175 }
176 
177 extern int do_huge_pmd_numa_page(struct mm_struct *mm, struct vm_area_struct *vma,
178 				unsigned long addr, pmd_t pmd, pmd_t *pmdp);
179 
180 #else /* CONFIG_TRANSPARENT_HUGEPAGE */
181 #define HPAGE_PMD_SHIFT ({ BUILD_BUG(); 0; })
182 #define HPAGE_PMD_MASK ({ BUILD_BUG(); 0; })
183 #define HPAGE_PMD_SIZE ({ BUILD_BUG(); 0; })
184 
185 #define hpage_nr_pages(x) 1
186 
187 #define transparent_hugepage_enabled(__vma) 0
188 
189 #define transparent_hugepage_flags 0UL
190 static inline int
191 split_huge_page_to_list(struct page *page, struct list_head *list)
192 {
193 	return 0;
194 }
195 static inline int split_huge_page(struct page *page)
196 {
197 	return 0;
198 }
199 #define split_huge_page_pmd(__vma, __address, __pmd)	\
200 	do { } while (0)
201 #define wait_split_huge_page(__anon_vma, __pmd)	\
202 	do { } while (0)
203 #define split_huge_page_pmd_mm(__mm, __address, __pmd)	\
204 	do { } while (0)
205 #define compound_trans_head(page) compound_head(page)
206 static inline int hugepage_madvise(struct vm_area_struct *vma,
207 				   unsigned long *vm_flags, int advice)
208 {
209 	BUG();
210 	return 0;
211 }
212 static inline void vma_adjust_trans_huge(struct vm_area_struct *vma,
213 					 unsigned long start,
214 					 unsigned long end,
215 					 long adjust_next)
216 {
217 }
218 static inline int pmd_trans_huge_lock(pmd_t *pmd,
219 				      struct vm_area_struct *vma)
220 {
221 	return 0;
222 }
223 
224 static inline int do_huge_pmd_numa_page(struct mm_struct *mm, struct vm_area_struct *vma,
225 					unsigned long addr, pmd_t pmd, pmd_t *pmdp)
226 {
227 	return 0;
228 }
229 
230 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
231 
232 #endif /* _LINUX_HUGE_MM_H */
233