[PATCH] Make most file operations structs in fs/ const
[linux-2.6.git] / include / linux / hugetlb.h
1 #ifndef _LINUX_HUGETLB_H
2 #define _LINUX_HUGETLB_H
3
4 #ifdef CONFIG_HUGETLB_PAGE
5
6 #include <linux/mempolicy.h>
7 #include <asm/tlbflush.h>
8
9 struct ctl_table;
10
11 static inline int is_vm_hugetlb_page(struct vm_area_struct *vma)
12 {
13         return vma->vm_flags & VM_HUGETLB;
14 }
15
16 int hugetlb_sysctl_handler(struct ctl_table *, int, struct file *, void __user *, size_t *, loff_t *);
17 int copy_hugetlb_page_range(struct mm_struct *, struct mm_struct *, struct vm_area_struct *);
18 int follow_hugetlb_page(struct mm_struct *, struct vm_area_struct *, struct page **, struct vm_area_struct **, unsigned long *, int *, int);
19 void unmap_hugepage_range(struct vm_area_struct *, unsigned long, unsigned long);
20 int hugetlb_prefault(struct address_space *, struct vm_area_struct *);
21 int hugetlb_report_meminfo(char *);
22 int hugetlb_report_node_meminfo(int, char *);
23 unsigned long hugetlb_total_pages(void);
24 int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
25                         unsigned long address, int write_access);
26
27 extern unsigned long max_huge_pages;
28 extern const unsigned long hugetlb_zero, hugetlb_infinity;
29 extern int sysctl_hugetlb_shm_group;
30
31 /* arch callbacks */
32
33 pte_t *huge_pte_alloc(struct mm_struct *mm, unsigned long addr);
34 pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr);
35 struct page *follow_huge_addr(struct mm_struct *mm, unsigned long address,
36                               int write);
37 struct page *follow_huge_pmd(struct mm_struct *mm, unsigned long address,
38                                 pmd_t *pmd, int write);
39 int pmd_huge(pmd_t pmd);
40 void hugetlb_change_protection(struct vm_area_struct *vma,
41                 unsigned long address, unsigned long end, pgprot_t newprot);
42
43 #ifndef ARCH_HAS_HUGEPAGE_ONLY_RANGE
44 #define is_hugepage_only_range(mm, addr, len)   0
45 #endif
46
47 #ifndef ARCH_HAS_HUGETLB_FREE_PGD_RANGE
48 #define hugetlb_free_pgd_range  free_pgd_range
49 #else
50 void hugetlb_free_pgd_range(struct mmu_gather **tlb, unsigned long addr,
51                             unsigned long end, unsigned long floor,
52                             unsigned long ceiling);
53 #endif
54
55 #ifndef ARCH_HAS_PREPARE_HUGEPAGE_RANGE
56 /*
57  * If the arch doesn't supply something else, assume that hugepage
58  * size aligned regions are ok without further preparation.
59  */
60 static inline int prepare_hugepage_range(unsigned long addr, unsigned long len)
61 {
62         if (len & ~HPAGE_MASK)
63                 return -EINVAL;
64         if (addr & ~HPAGE_MASK)
65                 return -EINVAL;
66         return 0;
67 }
68 #else
69 int prepare_hugepage_range(unsigned long addr, unsigned long len);
70 #endif
71
72 #ifndef ARCH_HAS_SETCLEAR_HUGE_PTE
73 #define set_huge_pte_at(mm, addr, ptep, pte)    set_pte_at(mm, addr, ptep, pte)
74 #define huge_ptep_get_and_clear(mm, addr, ptep) ptep_get_and_clear(mm, addr, ptep)
75 #else
76 void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
77                      pte_t *ptep, pte_t pte);
78 pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
79                               pte_t *ptep);
80 #endif
81
82 #ifndef ARCH_HAS_HUGETLB_PREFAULT_HOOK
83 #define hugetlb_prefault_arch_hook(mm)          do { } while (0)
84 #else
85 void hugetlb_prefault_arch_hook(struct mm_struct *mm);
86 #endif
87
88 #else /* !CONFIG_HUGETLB_PAGE */
89
90 static inline int is_vm_hugetlb_page(struct vm_area_struct *vma)
91 {
92         return 0;
93 }
94 static inline unsigned long hugetlb_total_pages(void)
95 {
96         return 0;
97 }
98
99 #define follow_hugetlb_page(m,v,p,vs,a,b,i)     ({ BUG(); 0; })
100 #define follow_huge_addr(mm, addr, write)       ERR_PTR(-EINVAL)
101 #define copy_hugetlb_page_range(src, dst, vma)  ({ BUG(); 0; })
102 #define hugetlb_prefault(mapping, vma)          ({ BUG(); 0; })
103 #define unmap_hugepage_range(vma, start, end)   BUG()
104 #define hugetlb_report_meminfo(buf)             0
105 #define hugetlb_report_node_meminfo(n, buf)     0
106 #define follow_huge_pmd(mm, addr, pmd, write)   NULL
107 #define prepare_hugepage_range(addr, len)       (-EINVAL)
108 #define pmd_huge(x)     0
109 #define is_hugepage_only_range(mm, addr, len)   0
110 #define hugetlb_free_pgd_range(tlb, addr, end, floor, ceiling) ({BUG(); 0; })
111 #define hugetlb_fault(mm, vma, addr, write)     ({ BUG(); 0; })
112
113 #define hugetlb_change_protection(vma, address, end, newprot)
114
115 #ifndef HPAGE_MASK
116 #define HPAGE_MASK      PAGE_MASK               /* Keep the compiler happy */
117 #define HPAGE_SIZE      PAGE_SIZE
118 #endif
119
120 #endif /* !CONFIG_HUGETLB_PAGE */
121
122 #ifdef CONFIG_HUGETLBFS
123 struct hugetlbfs_config {
124         uid_t   uid;
125         gid_t   gid;
126         umode_t mode;
127         long    nr_blocks;
128         long    nr_inodes;
129 };
130
131 struct hugetlbfs_sb_info {
132         long    max_blocks;   /* blocks allowed */
133         long    free_blocks;  /* blocks free */
134         long    max_inodes;   /* inodes allowed */
135         long    free_inodes;  /* inodes free */
136         spinlock_t      stat_lock;
137 };
138
139
140 struct hugetlbfs_inode_info {
141         struct shared_policy policy;
142         /* Protected by the (global) hugetlb_lock */
143         unsigned long prereserved_hpages;
144         struct inode vfs_inode;
145 };
146
147 static inline struct hugetlbfs_inode_info *HUGETLBFS_I(struct inode *inode)
148 {
149         return container_of(inode, struct hugetlbfs_inode_info, vfs_inode);
150 }
151
152 static inline struct hugetlbfs_sb_info *HUGETLBFS_SB(struct super_block *sb)
153 {
154         return sb->s_fs_info;
155 }
156
157 extern const struct file_operations hugetlbfs_file_operations;
158 extern struct vm_operations_struct hugetlb_vm_ops;
159 struct file *hugetlb_zero_setup(size_t);
160 int hugetlb_extend_reservation(struct hugetlbfs_inode_info *info,
161                                unsigned long atleast_hpages);
162 void hugetlb_truncate_reservation(struct hugetlbfs_inode_info *info,
163                                   unsigned long atmost_hpages);
164 int hugetlb_get_quota(struct address_space *mapping);
165 void hugetlb_put_quota(struct address_space *mapping);
166
167 static inline int is_file_hugepages(struct file *file)
168 {
169         return file->f_op == &hugetlbfs_file_operations;
170 }
171
172 static inline void set_file_hugepages(struct file *file)
173 {
174         file->f_op = &hugetlbfs_file_operations;
175 }
176 #else /* !CONFIG_HUGETLBFS */
177
178 #define is_file_hugepages(file)         0
179 #define set_file_hugepages(file)        BUG()
180 #define hugetlb_zero_setup(size)        ERR_PTR(-ENOSYS)
181
182 #endif /* !CONFIG_HUGETLBFS */
183
184 #endif /* _LINUX_HUGETLB_H */