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5#ifndef __LINUX_UIO_H
6#define __LINUX_UIO_H
7
8#include <linux/kernel.h>
9#include <linux/thread_info.h>
10#include <uapi/linux/uio.h>
11
12struct page;
13struct pipe_inode_info;
14
15struct kvec {
16 void *iov_base;
17 size_t iov_len;
18};
19
20enum iter_type {
21
22 ITER_IOVEC,
23 ITER_KVEC,
24 ITER_BVEC,
25 ITER_PIPE,
26 ITER_XARRAY,
27 ITER_DISCARD,
28};
29
30struct iov_iter_state {
31 size_t iov_offset;
32 size_t count;
33 unsigned long nr_segs;
34};
35
36struct iov_iter {
37 u8 iter_type;
38 bool data_source;
39 size_t iov_offset;
40 size_t count;
41 union {
42 const struct iovec *iov;
43 const struct kvec *kvec;
44 const struct bio_vec *bvec;
45 struct xarray *xarray;
46 struct pipe_inode_info *pipe;
47 };
48 union {
49 unsigned long nr_segs;
50 struct {
51 unsigned int head;
52 unsigned int start_head;
53 };
54 loff_t xarray_start;
55 };
56};
57
58static inline enum iter_type iov_iter_type(const struct iov_iter *i)
59{
60 return i->iter_type;
61}
62
63static inline void iov_iter_save_state(struct iov_iter *iter,
64 struct iov_iter_state *state)
65{
66 state->iov_offset = iter->iov_offset;
67 state->count = iter->count;
68 state->nr_segs = iter->nr_segs;
69}
70
71static inline bool iter_is_iovec(const struct iov_iter *i)
72{
73 return iov_iter_type(i) == ITER_IOVEC;
74}
75
76static inline bool iov_iter_is_kvec(const struct iov_iter *i)
77{
78 return iov_iter_type(i) == ITER_KVEC;
79}
80
81static inline bool iov_iter_is_bvec(const struct iov_iter *i)
82{
83 return iov_iter_type(i) == ITER_BVEC;
84}
85
86static inline bool iov_iter_is_pipe(const struct iov_iter *i)
87{
88 return iov_iter_type(i) == ITER_PIPE;
89}
90
91static inline bool iov_iter_is_discard(const struct iov_iter *i)
92{
93 return iov_iter_type(i) == ITER_DISCARD;
94}
95
96static inline bool iov_iter_is_xarray(const struct iov_iter *i)
97{
98 return iov_iter_type(i) == ITER_XARRAY;
99}
100
101static inline unsigned char iov_iter_rw(const struct iov_iter *i)
102{
103 return i->data_source ? WRITE : READ;
104}
105
106
107
108
109
110
111
112
113static inline size_t iov_length(const struct iovec *iov, unsigned long nr_segs)
114{
115 unsigned long seg;
116 size_t ret = 0;
117
118 for (seg = 0; seg < nr_segs; seg++)
119 ret += iov[seg].iov_len;
120 return ret;
121}
122
123static inline struct iovec iov_iter_iovec(const struct iov_iter *iter)
124{
125 return (struct iovec) {
126 .iov_base = iter->iov->iov_base + iter->iov_offset,
127 .iov_len = min(iter->count,
128 iter->iov->iov_len - iter->iov_offset),
129 };
130}
131
132size_t copy_page_from_iter_atomic(struct page *page, unsigned offset,
133 size_t bytes, struct iov_iter *i);
134void iov_iter_advance(struct iov_iter *i, size_t bytes);
135void iov_iter_revert(struct iov_iter *i, size_t bytes);
136int iov_iter_fault_in_readable(const struct iov_iter *i, size_t bytes);
137size_t iov_iter_single_seg_count(const struct iov_iter *i);
138size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes,
139 struct iov_iter *i);
140size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes,
141 struct iov_iter *i);
142
143size_t _copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i);
144size_t _copy_from_iter(void *addr, size_t bytes, struct iov_iter *i);
145size_t _copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i);
146
147static __always_inline __must_check
148size_t copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i)
149{
150 if (unlikely(!check_copy_size(addr, bytes, true)))
151 return 0;
152 else
153 return _copy_to_iter(addr, bytes, i);
154}
155
156static __always_inline __must_check
157size_t copy_from_iter(void *addr, size_t bytes, struct iov_iter *i)
158{
159 if (unlikely(!check_copy_size(addr, bytes, false)))
160 return 0;
161 else
162 return _copy_from_iter(addr, bytes, i);
163}
164
165static __always_inline __must_check
166bool copy_from_iter_full(void *addr, size_t bytes, struct iov_iter *i)
167{
168 size_t copied = copy_from_iter(addr, bytes, i);
169 if (likely(copied == bytes))
170 return true;
171 iov_iter_revert(i, copied);
172 return false;
173}
174
175static __always_inline __must_check
176size_t copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i)
177{
178 if (unlikely(!check_copy_size(addr, bytes, false)))
179 return 0;
180 else
181 return _copy_from_iter_nocache(addr, bytes, i);
182}
183
184static __always_inline __must_check
185bool copy_from_iter_full_nocache(void *addr, size_t bytes, struct iov_iter *i)
186{
187 size_t copied = copy_from_iter_nocache(addr, bytes, i);
188 if (likely(copied == bytes))
189 return true;
190 iov_iter_revert(i, copied);
191 return false;
192}
193
194#ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE
195
196
197
198
199
200
201size_t _copy_from_iter_flushcache(void *addr, size_t bytes, struct iov_iter *i);
202#else
203#define _copy_from_iter_flushcache _copy_from_iter_nocache
204#endif
205
206#ifdef CONFIG_ARCH_HAS_COPY_MC
207size_t _copy_mc_to_iter(const void *addr, size_t bytes, struct iov_iter *i);
208#else
209#define _copy_mc_to_iter _copy_to_iter
210#endif
211
212static __always_inline __must_check
213size_t copy_from_iter_flushcache(void *addr, size_t bytes, struct iov_iter *i)
214{
215 if (unlikely(!check_copy_size(addr, bytes, false)))
216 return 0;
217 else
218 return _copy_from_iter_flushcache(addr, bytes, i);
219}
220
221static __always_inline __must_check
222size_t copy_mc_to_iter(void *addr, size_t bytes, struct iov_iter *i)
223{
224 if (unlikely(!check_copy_size(addr, bytes, true)))
225 return 0;
226 else
227 return _copy_mc_to_iter(addr, bytes, i);
228}
229
230size_t iov_iter_zero(size_t bytes, struct iov_iter *);
231unsigned long iov_iter_alignment(const struct iov_iter *i);
232unsigned long iov_iter_gap_alignment(const struct iov_iter *i);
233void iov_iter_init(struct iov_iter *i, unsigned int direction, const struct iovec *iov,
234 unsigned long nr_segs, size_t count);
235void iov_iter_kvec(struct iov_iter *i, unsigned int direction, const struct kvec *kvec,
236 unsigned long nr_segs, size_t count);
237void iov_iter_bvec(struct iov_iter *i, unsigned int direction, const struct bio_vec *bvec,
238 unsigned long nr_segs, size_t count);
239void iov_iter_pipe(struct iov_iter *i, unsigned int direction, struct pipe_inode_info *pipe,
240 size_t count);
241void iov_iter_discard(struct iov_iter *i, unsigned int direction, size_t count);
242void iov_iter_xarray(struct iov_iter *i, unsigned int direction, struct xarray *xarray,
243 loff_t start, size_t count);
244ssize_t iov_iter_get_pages(struct iov_iter *i, struct page **pages,
245 size_t maxsize, unsigned maxpages, size_t *start);
246ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, struct page ***pages,
247 size_t maxsize, size_t *start);
248int iov_iter_npages(const struct iov_iter *i, int maxpages);
249void iov_iter_restore(struct iov_iter *i, struct iov_iter_state *state);
250
251const void *dup_iter(struct iov_iter *new, struct iov_iter *old, gfp_t flags);
252
253static inline size_t iov_iter_count(const struct iov_iter *i)
254{
255 return i->count;
256}
257
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260
261
262
263
264static inline void iov_iter_truncate(struct iov_iter *i, u64 count)
265{
266
267
268
269
270
271
272 if (i->count > count)
273 i->count = count;
274}
275
276
277
278
279
280static inline void iov_iter_reexpand(struct iov_iter *i, size_t count)
281{
282 i->count = count;
283}
284
285struct csum_state {
286 __wsum csum;
287 size_t off;
288};
289
290size_t csum_and_copy_to_iter(const void *addr, size_t bytes, void *csstate, struct iov_iter *i);
291size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum, struct iov_iter *i);
292
293static __always_inline __must_check
294bool csum_and_copy_from_iter_full(void *addr, size_t bytes,
295 __wsum *csum, struct iov_iter *i)
296{
297 size_t copied = csum_and_copy_from_iter(addr, bytes, csum, i);
298 if (likely(copied == bytes))
299 return true;
300 iov_iter_revert(i, copied);
301 return false;
302}
303size_t hash_and_copy_to_iter(const void *addr, size_t bytes, void *hashp,
304 struct iov_iter *i);
305
306struct iovec *iovec_from_user(const struct iovec __user *uvector,
307 unsigned long nr_segs, unsigned long fast_segs,
308 struct iovec *fast_iov, bool compat);
309ssize_t import_iovec(int type, const struct iovec __user *uvec,
310 unsigned nr_segs, unsigned fast_segs, struct iovec **iovp,
311 struct iov_iter *i);
312ssize_t __import_iovec(int type, const struct iovec __user *uvec,
313 unsigned nr_segs, unsigned fast_segs, struct iovec **iovp,
314 struct iov_iter *i, bool compat);
315int import_single_range(int type, void __user *buf, size_t len,
316 struct iovec *iov, struct iov_iter *i);
317
318#endif
319