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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
Herbert Xu42c271c2007-12-07 18:52:49 +08002 * Cryptographic scatter and gather helpers.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003 *
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>
Herbert Xu42c271c2007-12-07 18:52:49 +08007 * Copyright (c) 2007 Herbert Xu <herbert@gondor.apana.org.au>
Linus Torvalds1da177e2005-04-16 15:20:36 -07008 *
9 * This program is free software; you can redistribute it and/or modify it
10 * under the terms of the GNU General Public License as published by the Free
11 * Software Foundation; either version 2 of the License, or (at your option)
12 * any later version.
13 *
14 */
15
16#ifndef _CRYPTO_SCATTERWALK_H
17#define _CRYPTO_SCATTERWALK_H
Linus Torvalds1da177e2005-04-16 15:20:36 -070018
Herbert Xu42c271c2007-12-07 18:52:49 +080019#include <asm/kmap_types.h>
20#include <crypto/algapi.h>
21#include <linux/hardirq.h>
22#include <linux/highmem.h>
23#include <linux/kernel.h>
Herbert Xu5c640972006-08-12 21:56:17 +100024#include <linux/mm.h>
25#include <linux/scatterlist.h>
Herbert Xu1c5dfe62007-12-24 08:54:24 +080026#include <linux/sched.h>
Herbert Xu5c640972006-08-12 21:56:17 +100027
Herbert Xub2ab4a52007-12-05 20:59:25 +110028static inline void scatterwalk_sg_chain(struct scatterlist *sg1, int num,
29 struct scatterlist *sg2)
30{
31 sg_set_page(&sg1[num - 1], (void *)sg2, 0, 0);
Herbert Xu8ec970d2008-04-29 21:53:52 +080032 sg1[num - 1].page_link &= ~0x02;
Tom Lendacky41da8b52013-11-12 11:46:10 -060033 sg1[num - 1].page_link |= 0x01;
Herbert Xub2ab4a52007-12-05 20:59:25 +110034}
35
Steffen Klassert079f2f72010-11-22 11:25:50 +010036static inline void scatterwalk_crypto_chain(struct scatterlist *head,
37 struct scatterlist *sg,
38 int chain, int num)
39{
40 if (chain) {
41 head->length += sg->length;
Cristian Stoica5be4d4c2015-01-20 10:06:16 +020042 sg = sg_next(sg);
Steffen Klassert079f2f72010-11-22 11:25:50 +010043 }
44
45 if (sg)
46 scatterwalk_sg_chain(head, num, sg);
47 else
48 sg_mark_end(head);
49}
50
Herbert Xu5c640972006-08-12 21:56:17 +100051static inline unsigned long scatterwalk_samebuf(struct scatter_walk *walk_in,
52 struct scatter_walk *walk_out)
Linus Torvalds1da177e2005-04-16 15:20:36 -070053{
Jens Axboe78c2f0b2007-10-22 19:40:16 +020054 return !(((sg_page(walk_in->sg) - sg_page(walk_out->sg)) << PAGE_SHIFT) +
Herbert Xu5c640972006-08-12 21:56:17 +100055 (int)(walk_in->offset - walk_out->offset));
56}
57
58static inline unsigned int scatterwalk_pagelen(struct scatter_walk *walk)
59{
60 unsigned int len = walk->sg->offset + walk->sg->length - walk->offset;
61 unsigned int len_this_page = offset_in_page(~walk->offset) + 1;
62 return len_this_page > len ? len : len_this_page;
Linus Torvalds1da177e2005-04-16 15:20:36 -070063}
64
Herbert Xuc774e932005-07-06 13:51:31 -070065static inline unsigned int scatterwalk_clamp(struct scatter_walk *walk,
66 unsigned int nbytes)
Linus Torvalds1da177e2005-04-16 15:20:36 -070067{
Herbert Xu5c640972006-08-12 21:56:17 +100068 unsigned int len_this_page = scatterwalk_pagelen(walk);
69 return nbytes > len_this_page ? len_this_page : nbytes;
Linus Torvalds1da177e2005-04-16 15:20:36 -070070}
71
72static inline void scatterwalk_advance(struct scatter_walk *walk,
73 unsigned int nbytes)
74{
Linus Torvalds1da177e2005-04-16 15:20:36 -070075 walk->offset += nbytes;
Linus Torvalds1da177e2005-04-16 15:20:36 -070076}
77
Herbert Xu95477372005-07-06 13:52:09 -070078static inline unsigned int scatterwalk_aligned(struct scatter_walk *walk,
79 unsigned int alignmask)
80{
81 return !(walk->offset & alignmask);
82}
83
Herbert Xu5c640972006-08-12 21:56:17 +100084static inline struct page *scatterwalk_page(struct scatter_walk *walk)
85{
Jens Axboe78c2f0b2007-10-22 19:40:16 +020086 return sg_page(walk->sg) + (walk->offset >> PAGE_SHIFT);
Herbert Xu5c640972006-08-12 21:56:17 +100087}
88
Cong Wangf0dfc0b2011-11-25 23:14:17 +080089static inline void scatterwalk_unmap(void *vaddr)
Herbert Xu5c640972006-08-12 21:56:17 +100090{
Cong Wangf0dfc0b2011-11-25 23:14:17 +080091 kunmap_atomic(vaddr);
Herbert Xu5c640972006-08-12 21:56:17 +100092}
93
Linus Torvalds1da177e2005-04-16 15:20:36 -070094void scatterwalk_start(struct scatter_walk *walk, struct scatterlist *sg);
Herbert Xu5c640972006-08-12 21:56:17 +100095void scatterwalk_copychunks(void *buf, struct scatter_walk *walk,
96 size_t nbytes, int out);
Cong Wangf0dfc0b2011-11-25 23:14:17 +080097void *scatterwalk_map(struct scatter_walk *walk);
Linus Torvalds1da177e2005-04-16 15:20:36 -070098void scatterwalk_done(struct scatter_walk *walk, int out, int more);
99
Herbert Xu5fa0fea2007-08-29 16:31:34 +0800100void scatterwalk_map_and_copy(void *buf, struct scatterlist *sg,
101 unsigned int start, unsigned int nbytes, int out);
102
Joel Fernandes257aff52013-08-17 21:42:22 -0500103int scatterwalk_bytes_sglen(struct scatterlist *sg, int num_bytes);
104
Herbert Xufc42bcb2015-05-21 15:10:59 +0800105struct scatterlist *scatterwalk_ffwd(struct scatterlist dst[2],
106 struct scatterlist *src,
107 unsigned int len);
108
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109#endif /* _CRYPTO_SCATTERWALK_H */