tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * Cryptographic scatter and gather helpers.
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 * Copyright (c) 2007 Herbert Xu <herbert@gondor.apana.org.au>
8 *
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
18
19#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>
24#include <linux/mm.h>
25#include <linux/scatterlist.h>
26#include <linux/sched.h>
27
28static inline enum km_type crypto_kmap_type(int out)
29{
30 enum km_type type;
31
32 if (in_softirq())
33 type = out * (KM_SOFTIRQ1 - KM_SOFTIRQ0) + KM_SOFTIRQ0;
34 else
35 type = out * (KM_USER1 - KM_USER0) + KM_USER0;
36
37 return type;
38}
39
40static inline void *crypto_kmap(struct page *page, int out)
41{
42 return kmap_atomic(page, crypto_kmap_type(out));
43}
44
45static inline void crypto_kunmap(void *vaddr, int out)
46{
47 kunmap_atomic(vaddr, crypto_kmap_type(out));
48}
49
50static inline void crypto_yield(u32 flags)
51{
52 if (flags & CRYPTO_TFM_REQ_MAY_SLEEP)
53 cond_resched();
54}
55
56static inline void scatterwalk_sg_chain(struct scatterlist *sg1, int num,
57 struct scatterlist *sg2)
58{
59 sg_set_page(&sg1[num - 1], (void *)sg2, 0, 0);
60 sg1[num - 1].page_link &= ~0x02;
61}
62
63static inline struct scatterlist *scatterwalk_sg_next(struct scatterlist *sg)
64{
65 if (sg_is_last(sg))
66 return NULL;
67
68 return (++sg)->length ? sg : (void *)sg_page(sg);
69}
70
71static inline void scatterwalk_crypto_chain(struct scatterlist *head,
72 struct scatterlist *sg,
73 int chain, int num)
74{
75 if (chain) {
76 head->length += sg->length;
77 sg = scatterwalk_sg_next(sg);
78 }
79
80 if (sg)
81 scatterwalk_sg_chain(head, num, sg);
82 else
83 sg_mark_end(head);
84}
85
86static inline unsigned long scatterwalk_samebuf(struct scatter_walk *walk_in,
87 struct scatter_walk *walk_out)
88{
89 return !(((sg_page(walk_in->sg) - sg_page(walk_out->sg)) << PAGE_SHIFT) +
90 (int)(walk_in->offset - walk_out->offset));
91}
92
93static inline unsigned int scatterwalk_pagelen(struct scatter_walk *walk)
94{
95 unsigned int len = walk->sg->offset + walk->sg->length - walk->offset;
96 unsigned int len_this_page = offset_in_page(~walk->offset) + 1;
97 return len_this_page > len ? len : len_this_page;
98}
99
100static inline unsigned int scatterwalk_clamp(struct scatter_walk *walk,
101 unsigned int nbytes)
102{
103 unsigned int len_this_page = scatterwalk_pagelen(walk);
104 return nbytes > len_this_page ? len_this_page : nbytes;
105}
106
107static inline void scatterwalk_advance(struct scatter_walk *walk,
108 unsigned int nbytes)
109{
110 walk->offset += nbytes;
111}
112
113static inline unsigned int scatterwalk_aligned(struct scatter_walk *walk,
114 unsigned int alignmask)
115{
116 return !(walk->offset & alignmask);
117}
118
119static inline struct page *scatterwalk_page(struct scatter_walk *walk)
120{
121 return sg_page(walk->sg) + (walk->offset >> PAGE_SHIFT);
122}
123
124static inline void scatterwalk_unmap(void *vaddr, int out)
125{
126 crypto_kunmap(vaddr, out);
127}
128
129void scatterwalk_start(struct scatter_walk *walk, struct scatterlist *sg);
130void scatterwalk_copychunks(void *buf, struct scatter_walk *walk,
131 size_t nbytes, int out);
132void *scatterwalk_map(struct scatter_walk *walk, int out);
133void scatterwalk_done(struct scatter_walk *walk, int out, int more);
134
135void scatterwalk_map_and_copy(void *buf, struct scatterlist *sg,
136 unsigned int start, unsigned int nbytes, int out);
137
138#endif /* _CRYPTO_SCATTERWALK_H */