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9#ifndef __LINUX_UIO_H
10#define __LINUX_UIO_H
11
12#include <linux/kernel.h>
13#include <uapi/linux/uio.h>
14
15struct page;
16struct pipe_inode_info;
17
18struct kvec {
19 void *iov_base;
20 size_t iov_len;
21};
22
23enum {
24 ITER_IOVEC = 0,
25 ITER_KVEC = 2,
26 ITER_BVEC = 4,
27 ITER_PIPE = 8,
28};
29
30struct iov_iter {
31 int type;
32 size_t iov_offset;
33 size_t count;
34 union {
35 const struct iovec *iov;
36 const struct kvec *kvec;
37 const struct bio_vec *bvec;
38 struct pipe_inode_info *pipe;
39 };
40 union {
41 unsigned long nr_segs;
42 int idx;
43 };
44};
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53static inline size_t iov_length(const struct iovec *iov, unsigned long nr_segs)
54{
55 unsigned long seg;
56 size_t ret = 0;
57
58 for (seg = 0; seg < nr_segs; seg++)
59 ret += iov[seg].iov_len;
60 return ret;
61}
62
63static inline struct iovec iov_iter_iovec(const struct iov_iter *iter)
64{
65 return (struct iovec) {
66 .iov_base = iter->iov->iov_base + iter->iov_offset,
67 .iov_len = min(iter->count,
68 iter->iov->iov_len - iter->iov_offset),
69 };
70}
71
72#define iov_for_each(iov, iter, start) \
73 if (!((start).type & (ITER_BVEC | ITER_PIPE))) \
74 for (iter = (start); \
75 (iter).count && \
76 ((iov = iov_iter_iovec(&(iter))), 1); \
77 iov_iter_advance(&(iter), (iov).iov_len))
78
79unsigned long iov_shorten(struct iovec *iov, unsigned long nr_segs, size_t to);
80
81size_t iov_iter_copy_from_user_atomic(struct page *page,
82 struct iov_iter *i, unsigned long offset, size_t bytes);
83void iov_iter_advance(struct iov_iter *i, size_t bytes);
84int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes);
85size_t iov_iter_single_seg_count(const struct iov_iter *i);
86size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes,
87 struct iov_iter *i);
88size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes,
89 struct iov_iter *i);
90size_t copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i);
91size_t copy_from_iter(void *addr, size_t bytes, struct iov_iter *i);
92size_t copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i);
93size_t iov_iter_zero(size_t bytes, struct iov_iter *);
94unsigned long iov_iter_alignment(const struct iov_iter *i);
95unsigned long iov_iter_gap_alignment(const struct iov_iter *i);
96void iov_iter_init(struct iov_iter *i, int direction, const struct iovec *iov,
97 unsigned long nr_segs, size_t count);
98void iov_iter_kvec(struct iov_iter *i, int direction, const struct kvec *kvec,
99 unsigned long nr_segs, size_t count);
100void iov_iter_bvec(struct iov_iter *i, int direction, const struct bio_vec *bvec,
101 unsigned long nr_segs, size_t count);
102void iov_iter_pipe(struct iov_iter *i, int direction, struct pipe_inode_info *pipe,
103 size_t count);
104ssize_t iov_iter_get_pages(struct iov_iter *i, struct page **pages,
105 size_t maxsize, unsigned maxpages, size_t *start);
106ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, struct page ***pages,
107 size_t maxsize, size_t *start);
108int iov_iter_npages(const struct iov_iter *i, int maxpages);
109
110const void *dup_iter(struct iov_iter *new, struct iov_iter *old, gfp_t flags);
111
112static inline size_t iov_iter_count(const struct iov_iter *i)
113{
114 return i->count;
115}
116
117static inline bool iter_is_iovec(const struct iov_iter *i)
118{
119 return !(i->type & (ITER_BVEC | ITER_KVEC | ITER_PIPE));
120}
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128#define iov_iter_rw(i) ((0 ? (struct iov_iter *)0 : (i))->type & RW_MASK)
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136static inline void iov_iter_truncate(struct iov_iter *i, u64 count)
137{
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144 if (i->count > count)
145 i->count = count;
146}
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152static inline void iov_iter_reexpand(struct iov_iter *i, size_t count)
153{
154 i->count = count;
155}
156size_t csum_and_copy_to_iter(const void *addr, size_t bytes, __wsum *csum, struct iov_iter *i);
157size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum, struct iov_iter *i);
158
159int import_iovec(int type, const struct iovec __user * uvector,
160 unsigned nr_segs, unsigned fast_segs,
161 struct iovec **iov, struct iov_iter *i);
162
163#ifdef CONFIG_COMPAT
164struct compat_iovec;
165int compat_import_iovec(int type, const struct compat_iovec __user * uvector,
166 unsigned nr_segs, unsigned fast_segs,
167 struct iovec **iov, struct iov_iter *i);
168#endif
169
170int import_single_range(int type, void __user *buf, size_t len,
171 struct iovec *iov, struct iov_iter *i);
172
173#endif
174