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scatterwalk.h
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1 /*
2  * Cryptographic API.
3  *
4  * Copyright (c) 2002 James Morris <[email protected]>
5  * Copyright (c) 2002 Adam J. Richter <[email protected]>
6  * Copyright (c) 2004 Jean-Luc Cooke <[email protected]>
7  *
8  * This program is free software; you can redistribute it and/or modify it
9  * under the terms of the GNU General Public License as published by the Free
10  * Software Foundation; either version 2 of the License, or (at your option)
11  * any later version.
12  *
13  */
14 
15 #ifndef _CRYPTO_SCATTERWALK_H
16 #define _CRYPTO_SCATTERWALK_H
17 #include <linux/mm.h>
18 #include <asm/scatterlist.h>
19 
20 struct scatter_walk {
21  struct scatterlist *sg;
22  struct page *page;
23  void *data;
24  unsigned int len_this_page;
25  unsigned int len_this_segment;
26  unsigned int offset;
27 };
28 
29 /* Define sg_next is an inline routine now in case we want to change
30  scatterlist to a linked list later. */
31 static inline struct scatterlist *sg_next(struct scatterlist *sg)
32 {
33  return sg + 1;
34 }
35 
36 static inline int scatterwalk_samebuf(struct scatter_walk *walk_in,
37  struct scatter_walk *walk_out,
38  void *src_p, void *dst_p)
39 {
40  return walk_in->page == walk_out->page &&
41  walk_in->offset == walk_out->offset &&
42  walk_in->data == src_p && walk_out->data == dst_p;
43 }
44 
45 void *scatterwalk_whichbuf(struct scatter_walk *walk, unsigned int nbytes, void *scratch);
46 void scatterwalk_start(struct scatter_walk *walk, struct scatterlist *sg);
47 int scatterwalk_copychunks(void *buf, struct scatter_walk *walk, size_t nbytes, int out);
48 void scatterwalk_map(struct scatter_walk *walk, int out);
49 void scatterwalk_done(struct scatter_walk *walk, int out, int more);
50 
51 #endif /* _CRYPTO_SCATTERWALK_H */