xref: /linux-6.15/include/linux/huge_mm.h (revision 8c3a2b4c)
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 handle_pte_fault(struct mm_struct *mm,
100 			    struct vm_area_struct *vma, unsigned long address,
101 			    pte_t *pte, pmd_t *pmd, unsigned int flags);
102 extern int split_huge_page_to_list(struct page *page, struct list_head *list);
103 static inline int split_huge_page(struct page *page)
104 {
105 	return split_huge_page_to_list(page, NULL);
106 }
107 extern void __split_huge_page_pmd(struct vm_area_struct *vma,
108 		unsigned long address, pmd_t *pmd);
109 #define split_huge_page_pmd(__vma, __address, __pmd)			\
110 	do {								\
111 		pmd_t *____pmd = (__pmd);				\
112 		if (unlikely(pmd_trans_huge(*____pmd)))			\
113 			__split_huge_page_pmd(__vma, __address,		\
114 					____pmd);			\
115 	}  while (0)
116 #define wait_split_huge_page(__anon_vma, __pmd)				\
117 	do {								\
118 		pmd_t *____pmd = (__pmd);				\
119 		anon_vma_lock_write(__anon_vma);			\
120 		anon_vma_unlock_write(__anon_vma);			\
121 		BUG_ON(pmd_trans_splitting(*____pmd) ||			\
122 		       pmd_trans_huge(*____pmd));			\
123 	} while (0)
124 extern void split_huge_page_pmd_mm(struct mm_struct *mm, unsigned long address,
125 		pmd_t *pmd);
126 #if HPAGE_PMD_ORDER >= MAX_ORDER
127 #error "hugepages can't be allocated by the buddy allocator"
128 #endif
129 extern int hugepage_madvise(struct vm_area_struct *vma,
130 			    unsigned long *vm_flags, int advice);
131 extern void __vma_adjust_trans_huge(struct vm_area_struct *vma,
132 				    unsigned long start,
133 				    unsigned long end,
134 				    long adjust_next);
135 extern int __pmd_trans_huge_lock(pmd_t *pmd,
136 				 struct vm_area_struct *vma);
137 /* mmap_sem must be held on entry */
138 static inline int pmd_trans_huge_lock(pmd_t *pmd,
139 				      struct vm_area_struct *vma)
140 {
141 	VM_BUG_ON(!rwsem_is_locked(&vma->vm_mm->mmap_sem));
142 	if (pmd_trans_huge(*pmd))
143 		return __pmd_trans_huge_lock(pmd, vma);
144 	else
145 		return 0;
146 }
147 static inline void vma_adjust_trans_huge(struct vm_area_struct *vma,
148 					 unsigned long start,
149 					 unsigned long end,
150 					 long adjust_next)
151 {
152 	if (!vma->anon_vma || vma->vm_ops)
153 		return;
154 	__vma_adjust_trans_huge(vma, start, end, adjust_next);
155 }
156 static inline int hpage_nr_pages(struct page *page)
157 {
158 	if (unlikely(PageTransHuge(page)))
159 		return HPAGE_PMD_NR;
160 	return 1;
161 }
162 static inline struct page *compound_trans_head(struct page *page)
163 {
164 	if (PageTail(page)) {
165 		struct page *head;
166 		head = page->first_page;
167 		smp_rmb();
168 		/*
169 		 * head may be a dangling pointer.
170 		 * __split_huge_page_refcount clears PageTail before
171 		 * overwriting first_page, so if PageTail is still
172 		 * there it means the head pointer isn't dangling.
173 		 */
174 		if (PageTail(page))
175 			return head;
176 	}
177 	return page;
178 }
179 
180 extern int do_huge_pmd_numa_page(struct mm_struct *mm, struct vm_area_struct *vma,
181 				unsigned long addr, pmd_t pmd, pmd_t *pmdp);
182 
183 #else /* CONFIG_TRANSPARENT_HUGEPAGE */
184 #define HPAGE_PMD_SHIFT ({ BUILD_BUG(); 0; })
185 #define HPAGE_PMD_MASK ({ BUILD_BUG(); 0; })
186 #define HPAGE_PMD_SIZE ({ BUILD_BUG(); 0; })
187 
188 #define hpage_nr_pages(x) 1
189 
190 #define transparent_hugepage_enabled(__vma) 0
191 
192 #define transparent_hugepage_flags 0UL
193 static inline int
194 split_huge_page_to_list(struct page *page, struct list_head *list)
195 {
196 	return 0;
197 }
198 static inline int split_huge_page(struct page *page)
199 {
200 	return 0;
201 }
202 #define split_huge_page_pmd(__vma, __address, __pmd)	\
203 	do { } while (0)
204 #define wait_split_huge_page(__anon_vma, __pmd)	\
205 	do { } while (0)
206 #define split_huge_page_pmd_mm(__mm, __address, __pmd)	\
207 	do { } while (0)
208 #define compound_trans_head(page) compound_head(page)
209 static inline int hugepage_madvise(struct vm_area_struct *vma,
210 				   unsigned long *vm_flags, int advice)
211 {
212 	BUG();
213 	return 0;
214 }
215 static inline void vma_adjust_trans_huge(struct vm_area_struct *vma,
216 					 unsigned long start,
217 					 unsigned long end,
218 					 long adjust_next)
219 {
220 }
221 static inline int pmd_trans_huge_lock(pmd_t *pmd,
222 				      struct vm_area_struct *vma)
223 {
224 	return 0;
225 }
226 
227 static inline int do_huge_pmd_numa_page(struct mm_struct *mm, struct vm_area_struct *vma,
228 					unsigned long addr, pmd_t pmd, pmd_t *pmdp)
229 {
230 	return 0;
231 }
232 
233 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
234 
235 #endif /* _LINUX_HUGE_MM_H */
236