ia64/linux-2.6.18-xen.hg

view crypto/scatterwalk.h @ 912:dd42cdb0ab89

[IA64] Build blktap2 driver by default in x86 builds.

add CONFIG_XEN_BLKDEV_TAP2=y to buildconfigs/linux-defconfig_xen_ia64.

Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
author Isaku Yamahata <yamahata@valinux.co.jp>
date Mon Jun 29 12:09:16 2009 +0900 (2009-06-29)
parents 831230e53067
children
line source
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 */
15 #ifndef _CRYPTO_SCATTERWALK_H
16 #define _CRYPTO_SCATTERWALK_H
17 #include <linux/mm.h>
18 #include <asm/scatterlist.h>
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 };
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 }
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 }
43 static inline unsigned int scatterwalk_clamp(struct scatter_walk *walk,
44 unsigned int nbytes)
45 {
46 return nbytes > walk->len_this_page ? walk->len_this_page : nbytes;
47 }
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 }
58 static inline unsigned int scatterwalk_aligned(struct scatter_walk *walk,
59 unsigned int alignmask)
60 {
61 return !(walk->offset & alignmask);
62 }
64 void scatterwalk_start(struct scatter_walk *walk, struct scatterlist *sg);
65 int scatterwalk_copychunks(void *buf, struct scatter_walk *walk, size_t nbytes, int out);
66 void scatterwalk_map(struct scatter_walk *walk, int out);
67 void scatterwalk_done(struct scatter_walk *walk, int out, int more);
69 #endif /* _CRYPTO_SCATTERWALK_H */