1#ifndef _LINUX_HUGE_MM_H
2#define _LINUX_HUGE_MM_H
3
4extern 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);
8extern 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);
11extern 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);
15extern 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);
18extern struct page *follow_trans_huge_pmd(struct vm_area_struct *vma,
19					  unsigned long addr,
20					  pmd_t *pmd,
21					  unsigned int flags);
22extern int zap_huge_pmd(struct mmu_gather *tlb,
23			struct vm_area_struct *vma,
24			pmd_t *pmd, unsigned long addr);
25extern int mincore_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
26			unsigned long addr, unsigned long end,
27			unsigned char *vec);
28extern 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);
33extern int change_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
34			unsigned long addr, pgprot_t newprot,
35			int prot_numa);
36
37enum 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
49enum 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};
54extern 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				     spinlock_t **ptl);
59
60#define HPAGE_PMD_ORDER (HPAGE_PMD_SHIFT-PAGE_SHIFT)
61#define HPAGE_PMD_NR (1<<HPAGE_PMD_ORDER)
62
63#ifdef CONFIG_TRANSPARENT_HUGEPAGE
64#define HPAGE_PMD_SHIFT PMD_SHIFT
65#define HPAGE_PMD_SIZE	((1UL) << HPAGE_PMD_SHIFT)
66#define HPAGE_PMD_MASK	(~(HPAGE_PMD_SIZE - 1))
67
68extern bool is_vma_temporary_stack(struct vm_area_struct *vma);
69
70#define transparent_hugepage_enabled(__vma)				\
71	((transparent_hugepage_flags &					\
72	  (1<<TRANSPARENT_HUGEPAGE_FLAG) ||				\
73	  (transparent_hugepage_flags &					\
74	   (1<<TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG) &&			\
75	   ((__vma)->vm_flags & VM_HUGEPAGE))) &&			\
76	 !((__vma)->vm_flags & VM_NOHUGEPAGE) &&			\
77	 !is_vma_temporary_stack(__vma))
78#define transparent_hugepage_defrag(__vma)				\
79	((transparent_hugepage_flags &					\
80	  (1<<TRANSPARENT_HUGEPAGE_DEFRAG_FLAG)) ||			\
81	 (transparent_hugepage_flags &					\
82	  (1<<TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG) &&		\
83	  (__vma)->vm_flags & VM_HUGEPAGE))
84#define transparent_hugepage_use_zero_page()				\
85	(transparent_hugepage_flags &					\
86	 (1<<TRANSPARENT_HUGEPAGE_USE_ZERO_PAGE_FLAG))
87#ifdef CONFIG_DEBUG_VM
88#define transparent_hugepage_debug_cow()				\
89	(transparent_hugepage_flags &					\
90	 (1<<TRANSPARENT_HUGEPAGE_DEBUG_COW_FLAG))
91#else /* CONFIG_DEBUG_VM */
92#define transparent_hugepage_debug_cow() 0
93#endif /* CONFIG_DEBUG_VM */
94
95extern unsigned long transparent_hugepage_flags;
96extern int split_huge_page_to_list(struct page *page, struct list_head *list);
97static inline int split_huge_page(struct page *page)
98{
99	return split_huge_page_to_list(page, NULL);
100}
101extern void __split_huge_page_pmd(struct vm_area_struct *vma,
102		unsigned long address, pmd_t *pmd);
103#define split_huge_page_pmd(__vma, __address, __pmd)			\
104	do {								\
105		pmd_t *____pmd = (__pmd);				\
106		if (unlikely(pmd_trans_huge(*____pmd)))			\
107			__split_huge_page_pmd(__vma, __address,		\
108					____pmd);			\
109	}  while (0)
110#define wait_split_huge_page(__anon_vma, __pmd)				\
111	do {								\
112		pmd_t *____pmd = (__pmd);				\
113		anon_vma_lock_write(__anon_vma);			\
114		anon_vma_unlock_write(__anon_vma);			\
115		BUG_ON(pmd_trans_splitting(*____pmd) ||			\
116		       pmd_trans_huge(*____pmd));			\
117	} while (0)
118extern void split_huge_page_pmd_mm(struct mm_struct *mm, unsigned long address,
119		pmd_t *pmd);
120#if HPAGE_PMD_ORDER >= MAX_ORDER
121#error "hugepages can't be allocated by the buddy allocator"
122#endif
123extern int hugepage_madvise(struct vm_area_struct *vma,
124			    unsigned long *vm_flags, int advice);
125extern void __vma_adjust_trans_huge(struct vm_area_struct *vma,
126				    unsigned long start,
127				    unsigned long end,
128				    long adjust_next);
129extern int __pmd_trans_huge_lock(pmd_t *pmd, struct vm_area_struct *vma,
130		spinlock_t **ptl);
131/* mmap_sem must be held on entry */
132static inline int pmd_trans_huge_lock(pmd_t *pmd, struct vm_area_struct *vma,
133		spinlock_t **ptl)
134{
135	VM_BUG_ON_VMA(!rwsem_is_locked(&vma->vm_mm->mmap_sem), vma);
136	if (pmd_trans_huge(*pmd))
137		return __pmd_trans_huge_lock(pmd, vma, ptl);
138	else
139		return 0;
140}
141static inline void vma_adjust_trans_huge(struct vm_area_struct *vma,
142					 unsigned long start,
143					 unsigned long end,
144					 long adjust_next)
145{
146	if (!vma->anon_vma || vma->vm_ops)
147		return;
148	__vma_adjust_trans_huge(vma, start, end, adjust_next);
149}
150static inline int hpage_nr_pages(struct page *page)
151{
152	if (unlikely(PageTransHuge(page)))
153		return HPAGE_PMD_NR;
154	return 1;
155}
156
157extern int do_huge_pmd_numa_page(struct mm_struct *mm, struct vm_area_struct *vma,
158				unsigned long addr, pmd_t pmd, pmd_t *pmdp);
159
160extern struct page *huge_zero_page;
161
162static inline bool is_huge_zero_page(struct page *page)
163{
164	return ACCESS_ONCE(huge_zero_page) == page;
165}
166
167#else /* CONFIG_TRANSPARENT_HUGEPAGE */
168#define HPAGE_PMD_SHIFT ({ BUILD_BUG(); 0; })
169#define HPAGE_PMD_MASK ({ BUILD_BUG(); 0; })
170#define HPAGE_PMD_SIZE ({ BUILD_BUG(); 0; })
171
172#define hpage_nr_pages(x) 1
173
174#define transparent_hugepage_enabled(__vma) 0
175
176#define transparent_hugepage_flags 0UL
177static inline int
178split_huge_page_to_list(struct page *page, struct list_head *list)
179{
180	return 0;
181}
182static inline int split_huge_page(struct page *page)
183{
184	return 0;
185}
186#define split_huge_page_pmd(__vma, __address, __pmd)	\
187	do { } while (0)
188#define wait_split_huge_page(__anon_vma, __pmd)	\
189	do { } while (0)
190#define split_huge_page_pmd_mm(__mm, __address, __pmd)	\
191	do { } while (0)
192static inline int hugepage_madvise(struct vm_area_struct *vma,
193				   unsigned long *vm_flags, int advice)
194{
195	BUG();
196	return 0;
197}
198static inline void vma_adjust_trans_huge(struct vm_area_struct *vma,
199					 unsigned long start,
200					 unsigned long end,
201					 long adjust_next)
202{
203}
204static inline int pmd_trans_huge_lock(pmd_t *pmd, struct vm_area_struct *vma,
205		spinlock_t **ptl)
206{
207	return 0;
208}
209
210static inline int do_huge_pmd_numa_page(struct mm_struct *mm, struct vm_area_struct *vma,
211					unsigned long addr, pmd_t pmd, pmd_t *pmdp)
212{
213	return 0;
214}
215
216static inline bool is_huge_zero_page(struct page *page)
217{
218	return false;
219}
220
221#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
222
223#endif /* _LINUX_HUGE_MM_H */
224