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 int do_huge_pmd_wp_page(struct mm_struct *mm, struct vm_area_struct *vma,
12			       unsigned long address, pmd_t *pmd,
13			       pmd_t orig_pmd);
14extern pgtable_t get_pmd_huge_pte(struct mm_struct *mm);
15extern struct page *follow_trans_huge_pmd(struct mm_struct *mm,
16					  unsigned long addr,
17					  pmd_t *pmd,
18					  unsigned int flags);
19extern int zap_huge_pmd(struct mmu_gather *tlb,
20			struct vm_area_struct *vma,
21			pmd_t *pmd, unsigned long addr);
22extern int mincore_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
23			unsigned long addr, unsigned long end,
24			unsigned char *vec);
25extern int move_huge_pmd(struct vm_area_struct *vma,
26			 struct vm_area_struct *new_vma,
27			 unsigned long old_addr,
28			 unsigned long new_addr, unsigned long old_end,
29			 pmd_t *old_pmd, pmd_t *new_pmd);
30extern int change_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
31			unsigned long addr, pgprot_t newprot);
32
33enum transparent_hugepage_flag {
34	TRANSPARENT_HUGEPAGE_FLAG,
35	TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG,
36	TRANSPARENT_HUGEPAGE_DEFRAG_FLAG,
37	TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG,
38	TRANSPARENT_HUGEPAGE_DEFRAG_KHUGEPAGED_FLAG,
39#ifdef CONFIG_DEBUG_VM
40	TRANSPARENT_HUGEPAGE_DEBUG_COW_FLAG,
41#endif
42};
43
44enum page_check_address_pmd_flag {
45	PAGE_CHECK_ADDRESS_PMD_FLAG,
46	PAGE_CHECK_ADDRESS_PMD_NOTSPLITTING_FLAG,
47	PAGE_CHECK_ADDRESS_PMD_SPLITTING_FLAG,
48};
49extern pmd_t *page_check_address_pmd(struct page *page,
50				     struct mm_struct *mm,
51				     unsigned long address,
52				     enum page_check_address_pmd_flag flag);
53
54#define HPAGE_PMD_ORDER (HPAGE_PMD_SHIFT-PAGE_SHIFT)
55#define HPAGE_PMD_NR (1<<HPAGE_PMD_ORDER)
56
57#ifdef CONFIG_TRANSPARENT_HUGEPAGE
58#define HPAGE_PMD_SHIFT HPAGE_SHIFT
59#define HPAGE_PMD_MASK HPAGE_MASK
60#define HPAGE_PMD_SIZE HPAGE_SIZE
61
62#define transparent_hugepage_enabled(__vma)				\
63	((transparent_hugepage_flags &					\
64	  (1<<TRANSPARENT_HUGEPAGE_FLAG) ||				\
65	  (transparent_hugepage_flags &					\
66	   (1<<TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG) &&			\
67	   ((__vma)->vm_flags & VM_HUGEPAGE))) &&			\
68	 !((__vma)->vm_flags & VM_NOHUGEPAGE) &&			\
69	 !is_vma_temporary_stack(__vma))
70#define transparent_hugepage_defrag(__vma)				\
71	((transparent_hugepage_flags &					\
72	  (1<<TRANSPARENT_HUGEPAGE_DEFRAG_FLAG)) ||			\
73	 (transparent_hugepage_flags &					\
74	  (1<<TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG) &&		\
75	  (__vma)->vm_flags & VM_HUGEPAGE))
76#ifdef CONFIG_DEBUG_VM
77#define transparent_hugepage_debug_cow()				\
78	(transparent_hugepage_flags &					\
79	 (1<<TRANSPARENT_HUGEPAGE_DEBUG_COW_FLAG))
80#else /* CONFIG_DEBUG_VM */
81#define transparent_hugepage_debug_cow() 0
82#endif /* CONFIG_DEBUG_VM */
83
84extern unsigned long transparent_hugepage_flags;
85extern int copy_pte_range(struct mm_struct *dst_mm, struct mm_struct *src_mm,
86			  pmd_t *dst_pmd, pmd_t *src_pmd,
87			  struct vm_area_struct *vma,
88			  unsigned long addr, unsigned long end);
89extern int handle_pte_fault(struct mm_struct *mm,
90			    struct vm_area_struct *vma, unsigned long address,
91			    pte_t *pte, pmd_t *pmd, unsigned int flags);
92extern int split_huge_page(struct page *page);
93extern void __split_huge_page_pmd(struct mm_struct *mm, pmd_t *pmd);
94#define split_huge_page_pmd(__mm, __pmd)				\
95	do {								\
96		pmd_t *____pmd = (__pmd);				\
97		if (unlikely(pmd_trans_huge(*____pmd)))			\
98			__split_huge_page_pmd(__mm, ____pmd);		\
99	}  while (0)
100#define wait_split_huge_page(__anon_vma, __pmd)				\
101	do {								\
102		pmd_t *____pmd = (__pmd);				\
103		anon_vma_lock(__anon_vma);				\
104		anon_vma_unlock(__anon_vma);				\
105		BUG_ON(pmd_trans_splitting(*____pmd) ||			\
106		       pmd_trans_huge(*____pmd));			\
107	} while (0)
108#if HPAGE_PMD_ORDER > MAX_ORDER
109#error "hugepages can't be allocated by the buddy allocator"
110#endif
111extern int hugepage_madvise(struct vm_area_struct *vma,
112			    unsigned long *vm_flags, int advice);
113extern void __vma_adjust_trans_huge(struct vm_area_struct *vma,
114				    unsigned long start,
115				    unsigned long end,
116				    long adjust_next);
117extern int __pmd_trans_huge_lock(pmd_t *pmd,
118				 struct vm_area_struct *vma);
119/* mmap_sem must be held on entry */
120static inline int pmd_trans_huge_lock(pmd_t *pmd,
121				      struct vm_area_struct *vma)
122{
123	VM_BUG_ON(!rwsem_is_locked(&vma->vm_mm->mmap_sem));
124	if (pmd_trans_huge(*pmd))
125		return __pmd_trans_huge_lock(pmd, vma);
126	else
127		return 0;
128}
129static inline void vma_adjust_trans_huge(struct vm_area_struct *vma,
130					 unsigned long start,
131					 unsigned long end,
132					 long adjust_next)
133{
134	if (!vma->anon_vma || vma->vm_ops)
135		return;
136	__vma_adjust_trans_huge(vma, start, end, adjust_next);
137}
138static inline int hpage_nr_pages(struct page *page)
139{
140	if (unlikely(PageTransHuge(page)))
141		return HPAGE_PMD_NR;
142	return 1;
143}
144static inline struct page *compound_trans_head(struct page *page)
145{
146	if (PageTail(page)) {
147		struct page *head;
148		head = page->first_page;
149		smp_rmb();
150		/*
151		 * head may be a dangling pointer.
152		 * __split_huge_page_refcount clears PageTail before
153		 * overwriting first_page, so if PageTail is still
154		 * there it means the head pointer isn't dangling.
155		 */
156		if (PageTail(page))
157			return head;
158	}
159	return page;
160}
161#else /* CONFIG_TRANSPARENT_HUGEPAGE */
162#define HPAGE_PMD_SHIFT ({ BUILD_BUG(); 0; })
163#define HPAGE_PMD_MASK ({ BUILD_BUG(); 0; })
164#define HPAGE_PMD_SIZE ({ BUILD_BUG(); 0; })
165
166#define hpage_nr_pages(x) 1
167
168#define transparent_hugepage_enabled(__vma) 0
169
170#define transparent_hugepage_flags 0UL
171static inline int split_huge_page(struct page *page)
172{
173	return 0;
174}
175#define split_huge_page_pmd(__mm, __pmd)	\
176	do { } while (0)
177#define wait_split_huge_page(__anon_vma, __pmd)	\
178	do { } while (0)
179#define compound_trans_head(page) compound_head(page)
180static inline int hugepage_madvise(struct vm_area_struct *vma,
181				   unsigned long *vm_flags, int advice)
182{
183	BUG();
184	return 0;
185}
186static inline void vma_adjust_trans_huge(struct vm_area_struct *vma,
187					 unsigned long start,
188					 unsigned long end,
189					 long adjust_next)
190{
191}
192static inline int pmd_trans_huge_lock(pmd_t *pmd,
193				      struct vm_area_struct *vma)
194{
195	return 0;
196}
197#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
198
199#endif /* _LINUX_HUGE_MM_H */
200