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9#ifndef __LINUX_UIO_H
10#define __LINUX_UIO_H
11
12#include <linux/kernel.h>
13#include <linux/thread_info.h>
14#include <uapi/linux/uio.h>
15
16struct page;
17struct pipe_inode_info;
18
19struct kvec {
20 void *iov_base;
21 size_t iov_len;
22};
23
24enum {
25 ITER_IOVEC = 0,
26 ITER_KVEC = 2,
27 ITER_BVEC = 4,
28 ITER_PIPE = 8,
29};
30
31struct iov_iter {
32 int type;
33 size_t iov_offset;
34 size_t count;
35 union {
36 const struct iovec *iov;
37 const struct kvec *kvec;
38 const struct bio_vec *bvec;
39 struct pipe_inode_info *pipe;
40 };
41 union {
42 unsigned long nr_segs;
43 struct {
44 int idx;
45 int start_idx;
46 };
47 };
48};
49
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56
57static inline size_t iov_length(const struct iovec *iov, unsigned long nr_segs)
58{
59 unsigned long seg;
60 size_t ret = 0;
61
62 for (seg = 0; seg < nr_segs; seg++)
63 ret += iov[seg].iov_len;
64 return ret;
65}
66
67static inline struct iovec iov_iter_iovec(const struct iov_iter *iter)
68{
69 return (struct iovec) {
70 .iov_base = iter->iov->iov_base + iter->iov_offset,
71 .iov_len = min(iter->count,
72 iter->iov->iov_len - iter->iov_offset),
73 };
74}
75
76#define iov_for_each(iov, iter, start) \
77 if (!((start).type & (ITER_BVEC | ITER_PIPE))) \
78 for (iter = (start); \
79 (iter).count && \
80 ((iov = iov_iter_iovec(&(iter))), 1); \
81 iov_iter_advance(&(iter), (iov).iov_len))
82
83unsigned long iov_shorten(struct iovec *iov, unsigned long nr_segs, size_t to);
84
85size_t iov_iter_copy_from_user_atomic(struct page *page,
86 struct iov_iter *i, unsigned long offset, size_t bytes);
87void iov_iter_advance(struct iov_iter *i, size_t bytes);
88void iov_iter_revert(struct iov_iter *i, size_t bytes);
89int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes);
90size_t iov_iter_single_seg_count(const struct iov_iter *i);
91size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes,
92 struct iov_iter *i);
93size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes,
94 struct iov_iter *i);
95
96size_t _copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i);
97size_t _copy_from_iter(void *addr, size_t bytes, struct iov_iter *i);
98bool _copy_from_iter_full(void *addr, size_t bytes, struct iov_iter *i);
99size_t _copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i);
100bool _copy_from_iter_full_nocache(void *addr, size_t bytes, struct iov_iter *i);
101
102static __always_inline __must_check
103size_t copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i)
104{
105 if (unlikely(!check_copy_size(addr, bytes, true)))
106 return 0;
107 else
108 return _copy_to_iter(addr, bytes, i);
109}
110
111static __always_inline __must_check
112size_t copy_from_iter(void *addr, size_t bytes, struct iov_iter *i)
113{
114 if (unlikely(!check_copy_size(addr, bytes, false)))
115 return 0;
116 else
117 return _copy_from_iter(addr, bytes, i);
118}
119
120static __always_inline __must_check
121bool copy_from_iter_full(void *addr, size_t bytes, struct iov_iter *i)
122{
123 if (unlikely(!check_copy_size(addr, bytes, false)))
124 return false;
125 else
126 return _copy_from_iter_full(addr, bytes, i);
127}
128
129static __always_inline __must_check
130size_t copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i)
131{
132 if (unlikely(!check_copy_size(addr, bytes, false)))
133 return 0;
134 else
135 return _copy_from_iter_nocache(addr, bytes, i);
136}
137
138static __always_inline __must_check
139bool copy_from_iter_full_nocache(void *addr, size_t bytes, struct iov_iter *i)
140{
141 if (unlikely(!check_copy_size(addr, bytes, false)))
142 return false;
143 else
144 return _copy_from_iter_full_nocache(addr, bytes, i);
145}
146
147#ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE
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154size_t _copy_from_iter_flushcache(void *addr, size_t bytes, struct iov_iter *i);
155#else
156#define _copy_from_iter_flushcache _copy_from_iter_nocache
157#endif
158
159static __always_inline __must_check
160size_t copy_from_iter_flushcache(void *addr, size_t bytes, struct iov_iter *i)
161{
162 if (unlikely(!check_copy_size(addr, bytes, false)))
163 return 0;
164 else
165 return _copy_from_iter_flushcache(addr, bytes, i);
166}
167
168size_t iov_iter_zero(size_t bytes, struct iov_iter *);
169unsigned long iov_iter_alignment(const struct iov_iter *i);
170unsigned long iov_iter_gap_alignment(const struct iov_iter *i);
171void iov_iter_init(struct iov_iter *i, int direction, const struct iovec *iov,
172 unsigned long nr_segs, size_t count);
173void iov_iter_kvec(struct iov_iter *i, int direction, const struct kvec *kvec,
174 unsigned long nr_segs, size_t count);
175void iov_iter_bvec(struct iov_iter *i, int direction, const struct bio_vec *bvec,
176 unsigned long nr_segs, size_t count);
177void iov_iter_pipe(struct iov_iter *i, int direction, struct pipe_inode_info *pipe,
178 size_t count);
179ssize_t iov_iter_get_pages(struct iov_iter *i, struct page **pages,
180 size_t maxsize, unsigned maxpages, size_t *start);
181ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, struct page ***pages,
182 size_t maxsize, size_t *start);
183int iov_iter_npages(const struct iov_iter *i, int maxpages);
184
185const void *dup_iter(struct iov_iter *new, struct iov_iter *old, gfp_t flags);
186
187static inline size_t iov_iter_count(const struct iov_iter *i)
188{
189 return i->count;
190}
191
192static inline bool iter_is_iovec(const struct iov_iter *i)
193{
194 return !(i->type & (ITER_BVEC | ITER_KVEC | ITER_PIPE));
195}
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203#define iov_iter_rw(i) ((0 ? (struct iov_iter *)0 : (i))->type & (READ | WRITE))
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211static inline void iov_iter_truncate(struct iov_iter *i, u64 count)
212{
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217
218
219 if (i->count > count)
220 i->count = count;
221}
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227static inline void iov_iter_reexpand(struct iov_iter *i, size_t count)
228{
229 i->count = count;
230}
231size_t csum_and_copy_to_iter(const void *addr, size_t bytes, __wsum *csum, struct iov_iter *i);
232size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum, struct iov_iter *i);
233bool csum_and_copy_from_iter_full(void *addr, size_t bytes, __wsum *csum, struct iov_iter *i);
234
235int import_iovec(int type, const struct iovec __user * uvector,
236 unsigned nr_segs, unsigned fast_segs,
237 struct iovec **iov, struct iov_iter *i);
238
239#ifdef CONFIG_COMPAT
240struct compat_iovec;
241int compat_import_iovec(int type, const struct compat_iovec __user * uvector,
242 unsigned nr_segs, unsigned fast_segs,
243 struct iovec **iov, struct iov_iter *i);
244#endif
245
246int import_single_range(int type, void __user *buf, size_t len,
247 struct iovec *iov, struct iov_iter *i);
248
249#endif
250