projects / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 1da177e4 LT |
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 | { | |
| 39 | return walk_in->page == walk_out->page && | |
| 40 | walk_in->offset == walk_out->offset; | |
| 41 | } | |
| 42 | ||
| c774e93e HX |
43 | static inline unsigned int scatterwalk_clamp(struct scatter_walk *walk, |
| 44 | unsigned int nbytes) | |
| 1da177e4 | 45 | { |
| c774e93e | 46 | return nbytes > walk->len_this_page ? walk->len_this_page : nbytes; |
| 1da177e4 LT |
47 | } |
| 48 | ||
| 49 | static inline void scatterwalk_advance(struct scatter_walk *walk, | |
| 50 | unsigned int nbytes) | |
| 51 | { | |
| 52 | walk->data += nbytes; | |
| 53 | walk->offset += nbytes; | |
| 54 | walk->len_this_page -= nbytes; | |
| 55 | walk->len_this_segment -= nbytes; | |
| 56 | } | |
| 57 | ||
| 58 | void scatterwalk_start(struct scatter_walk *walk, struct scatterlist *sg); | |
| 59 | int scatterwalk_copychunks(void *buf, struct scatter_walk *walk, size_t nbytes, int out); | |
| 60 | void scatterwalk_map(struct scatter_walk *walk, int out); | |
| 61 | void scatterwalk_done(struct scatter_walk *walk, int out, int more); | |
| 62 | ||
| 63 | #endif /* _CRYPTO_SCATTERWALK_H */ |