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4
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 {
31 u8 iter_type;
32 bool data_source;
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 xarray *xarray;
40 struct pipe_inode_info *pipe;
41 };
42 union {
43 unsigned long nr_segs;
44 struct {
45 unsigned int head;
46 unsigned int start_head;
47 };
48 loff_t xarray_start;
49 };
50};
51
52static inline enum iter_type iov_iter_type(const struct iov_iter *i)
53{
54 return i->iter_type;
55}
56
57static inline bool iter_is_iovec(const struct iov_iter *i)
58{
59 return iov_iter_type(i) == ITER_IOVEC;
60}
61
62static inline bool iov_iter_is_kvec(const struct iov_iter *i)
63{
64 return iov_iter_type(i) == ITER_KVEC;
65}
66
67static inline bool iov_iter_is_bvec(const struct iov_iter *i)
68{
69 return iov_iter_type(i) == ITER_BVEC;
70}
71
72static inline bool iov_iter_is_pipe(const struct iov_iter *i)
73{
74 return iov_iter_type(i) == ITER_PIPE;
75}
76
77static inline bool iov_iter_is_discard(const struct iov_iter *i)
78{
79 return iov_iter_type(i) == ITER_DISCARD;
80}
81
82static inline bool iov_iter_is_xarray(const struct iov_iter *i)
83{
84 return iov_iter_type(i) == ITER_XARRAY;
85}
86
87static inline unsigned char iov_iter_rw(const struct iov_iter *i)
88{
89 return i->data_source ? WRITE : READ;
90}
91
92
93
94
95
96
97
98
99static inline size_t iov_length(const struct iovec *iov, unsigned long nr_segs)
100{
101 unsigned long seg;
102 size_t ret = 0;
103
104 for (seg = 0; seg < nr_segs; seg++)
105 ret += iov[seg].iov_len;
106 return ret;
107}
108
109static inline struct iovec iov_iter_iovec(const struct iov_iter *iter)
110{
111 return (struct iovec) {
112 .iov_base = iter->iov->iov_base + iter->iov_offset,
113 .iov_len = min(iter->count,
114 iter->iov->iov_len - iter->iov_offset),
115 };
116}
117
118size_t copy_page_from_iter_atomic(struct page *page, unsigned offset,
119 size_t bytes, struct iov_iter *i);
120void iov_iter_advance(struct iov_iter *i, size_t bytes);
121void iov_iter_revert(struct iov_iter *i, size_t bytes);
122int iov_iter_fault_in_readable(const struct iov_iter *i, size_t bytes);
123size_t iov_iter_single_seg_count(const struct iov_iter *i);
124size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes,
125 struct iov_iter *i);
126size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes,
127 struct iov_iter *i);
128
129size_t _copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i);
130size_t _copy_from_iter(void *addr, size_t bytes, struct iov_iter *i);
131size_t _copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i);
132
133static __always_inline __must_check
134size_t copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i)
135{
136 if (unlikely(!check_copy_size(addr, bytes, true)))
137 return 0;
138 else
139 return _copy_to_iter(addr, bytes, i);
140}
141
142static __always_inline __must_check
143size_t copy_from_iter(void *addr, size_t bytes, struct iov_iter *i)
144{
145 if (unlikely(!check_copy_size(addr, bytes, false)))
146 return 0;
147 else
148 return _copy_from_iter(addr, bytes, i);
149}
150
151static __always_inline __must_check
152bool copy_from_iter_full(void *addr, size_t bytes, struct iov_iter *i)
153{
154 size_t copied = copy_from_iter(addr, bytes, i);
155 if (likely(copied == bytes))
156 return true;
157 iov_iter_revert(i, copied);
158 return false;
159}
160
161static __always_inline __must_check
162size_t copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i)
163{
164 if (unlikely(!check_copy_size(addr, bytes, false)))
165 return 0;
166 else
167 return _copy_from_iter_nocache(addr, bytes, i);
168}
169
170static __always_inline __must_check
171bool copy_from_iter_full_nocache(void *addr, size_t bytes, struct iov_iter *i)
172{
173 size_t copied = copy_from_iter_nocache(addr, bytes, i);
174 if (likely(copied == bytes))
175 return true;
176 iov_iter_revert(i, copied);
177 return false;
178}
179
180#ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE
181
182
183
184
185
186
187size_t _copy_from_iter_flushcache(void *addr, size_t bytes, struct iov_iter *i);
188#else
189#define _copy_from_iter_flushcache _copy_from_iter_nocache
190#endif
191
192#ifdef CONFIG_ARCH_HAS_COPY_MC
193size_t _copy_mc_to_iter(const void *addr, size_t bytes, struct iov_iter *i);
194#else
195#define _copy_mc_to_iter _copy_to_iter
196#endif
197
198static __always_inline __must_check
199size_t copy_from_iter_flushcache(void *addr, size_t bytes, struct iov_iter *i)
200{
201 if (unlikely(!check_copy_size(addr, bytes, false)))
202 return 0;
203 else
204 return _copy_from_iter_flushcache(addr, bytes, i);
205}
206
207static __always_inline __must_check
208size_t copy_mc_to_iter(void *addr, size_t bytes, struct iov_iter *i)
209{
210 if (unlikely(!check_copy_size(addr, bytes, true)))
211 return 0;
212 else
213 return _copy_mc_to_iter(addr, bytes, i);
214}
215
216size_t iov_iter_zero(size_t bytes, struct iov_iter *);
217unsigned long iov_iter_alignment(const struct iov_iter *i);
218unsigned long iov_iter_gap_alignment(const struct iov_iter *i);
219void iov_iter_init(struct iov_iter *i, unsigned int direction, const struct iovec *iov,
220 unsigned long nr_segs, size_t count);
221void iov_iter_kvec(struct iov_iter *i, unsigned int direction, const struct kvec *kvec,
222 unsigned long nr_segs, size_t count);
223void iov_iter_bvec(struct iov_iter *i, unsigned int direction, const struct bio_vec *bvec,
224 unsigned long nr_segs, size_t count);
225void iov_iter_pipe(struct iov_iter *i, unsigned int direction, struct pipe_inode_info *pipe,
226 size_t count);
227void iov_iter_discard(struct iov_iter *i, unsigned int direction, size_t count);
228void iov_iter_xarray(struct iov_iter *i, unsigned int direction, struct xarray *xarray,
229 loff_t start, size_t count);
230ssize_t iov_iter_get_pages(struct iov_iter *i, struct page **pages,
231 size_t maxsize, unsigned maxpages, size_t *start);
232ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, struct page ***pages,
233 size_t maxsize, size_t *start);
234int iov_iter_npages(const struct iov_iter *i, int maxpages);
235
236const void *dup_iter(struct iov_iter *new, struct iov_iter *old, gfp_t flags);
237
238static inline size_t iov_iter_count(const struct iov_iter *i)
239{
240 return i->count;
241}
242
243
244
245
246
247
248
249static inline void iov_iter_truncate(struct iov_iter *i, u64 count)
250{
251
252
253
254
255
256
257 if (i->count > count)
258 i->count = count;
259}
260
261
262
263
264
265static inline void iov_iter_reexpand(struct iov_iter *i, size_t count)
266{
267 i->count = count;
268}
269
270struct csum_state {
271 __wsum csum;
272 size_t off;
273};
274
275size_t csum_and_copy_to_iter(const void *addr, size_t bytes, void *csstate, struct iov_iter *i);
276size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum, struct iov_iter *i);
277
278static __always_inline __must_check
279bool csum_and_copy_from_iter_full(void *addr, size_t bytes,
280 __wsum *csum, struct iov_iter *i)
281{
282 size_t copied = csum_and_copy_from_iter(addr, bytes, csum, i);
283 if (likely(copied == bytes))
284 return true;
285 iov_iter_revert(i, copied);
286 return false;
287}
288size_t hash_and_copy_to_iter(const void *addr, size_t bytes, void *hashp,
289 struct iov_iter *i);
290
291struct iovec *iovec_from_user(const struct iovec __user *uvector,
292 unsigned long nr_segs, unsigned long fast_segs,
293 struct iovec *fast_iov, bool compat);
294ssize_t import_iovec(int type, const struct iovec __user *uvec,
295 unsigned nr_segs, unsigned fast_segs, struct iovec **iovp,
296 struct iov_iter *i);
297ssize_t __import_iovec(int type, const struct iovec __user *uvec,
298 unsigned nr_segs, unsigned fast_segs, struct iovec **iovp,
299 struct iov_iter *i, bool compat);
300int import_single_range(int type, void __user *buf, size_t len,
301 struct iovec *iov, struct iov_iter *i);
302
303#endif
304