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>
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)
15 #ifndef _CRYPTO_SCATTERWALK_H
16 #define _CRYPTO_SCATTERWALK_H
19 #include <linux/scatterlist.h>
23 /* Define sg_next is an inline routine now in case we want to change
24 scatterlist to a linked list later. */
25 static inline struct scatterlist *sg_next(struct scatterlist *sg)
30 static inline unsigned long scatterwalk_samebuf(struct scatter_walk *walk_in,
31 struct scatter_walk *walk_out)
33 return !(((walk_in->sg->page - walk_out->sg->page) << PAGE_SHIFT) +
34 (int)(walk_in->offset - walk_out->offset));
37 static inline unsigned int scatterwalk_pagelen(struct scatter_walk *walk)
39 unsigned int len = walk->sg->offset + walk->sg->length - walk->offset;
40 unsigned int len_this_page = offset_in_page(~walk->offset) + 1;
41 return len_this_page > len ? len : len_this_page;
44 static inline unsigned int scatterwalk_clamp(struct scatter_walk *walk,
47 unsigned int len_this_page = scatterwalk_pagelen(walk);
48 return nbytes > len_this_page ? len_this_page : nbytes;
51 static inline void scatterwalk_advance(struct scatter_walk *walk,
54 walk->offset += nbytes;
57 static inline unsigned int scatterwalk_aligned(struct scatter_walk *walk,
58 unsigned int alignmask)
60 return !(walk->offset & alignmask);
63 static inline struct page *scatterwalk_page(struct scatter_walk *walk)
65 return walk->sg->page + (walk->offset >> PAGE_SHIFT);
68 static inline void scatterwalk_unmap(void *vaddr, int out)
70 crypto_kunmap(vaddr, out);
73 void scatterwalk_start(struct scatter_walk *walk, struct scatterlist *sg);
74 void scatterwalk_copychunks(void *buf, struct scatter_walk *walk,
75 size_t nbytes, int out);
76 void *scatterwalk_map(struct scatter_walk *walk, int out);
77 void scatterwalk_done(struct scatter_walk *walk, int out, int more);
79 #endif /* _CRYPTO_SCATTERWALK_H */