| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Cryptographic API. |
| 3 | * |
| 4 | * Copyright (c) 2002 James Morris <jmorris@intercode.com.au> |
| 5 | * Copyright (c) 2002 Adam J. Richter <adam@yggdrasil.com> |
| 6 | * Copyright (c) 2004 Jean-Luc Cooke <jlcooke@certainkey.com> |
| 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 | |
| 43 | static inline int scatterwalk_across_pages(struct scatter_walk *walk, |
| 44 | unsigned int nbytes) |
| 45 | { |
| 46 | return nbytes > walk->len_this_page; |
| 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 */ |