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
crypto_kmap_type(int out)28 static 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
crypto_kmap(struct page * page,int out)40 static inline void *crypto_kmap(struct page *page, int out)
41 {
42 return kmap_atomic(page, crypto_kmap_type(out));
43 }
44
crypto_kunmap(void * vaddr,int out)45 static inline void crypto_kunmap(void *vaddr, int out)
46 {
47 kunmap_atomic(vaddr, crypto_kmap_type(out));
48 }
49
crypto_yield(u32 flags)50 static inline void crypto_yield(u32 flags)
51 {
52 if (flags & CRYPTO_TFM_REQ_MAY_SLEEP)
53 cond_resched();
54 }
55
scatterwalk_sg_chain(struct scatterlist * sg1,int num,struct scatterlist * sg2)56 static 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
scatterwalk_sg_next(struct scatterlist * sg)63 static 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
scatterwalk_crypto_chain(struct scatterlist * head,struct scatterlist * sg,int chain,int num)71 static 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
scatterwalk_samebuf(struct scatter_walk * walk_in,struct scatter_walk * walk_out)86 static 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
scatterwalk_pagelen(struct scatter_walk * walk)93 static 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
scatterwalk_clamp(struct scatter_walk * walk,unsigned int nbytes)100 static 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
scatterwalk_advance(struct scatter_walk * walk,unsigned int nbytes)107 static inline void scatterwalk_advance(struct scatter_walk *walk,
108 unsigned int nbytes)
109 {
110 walk->offset += nbytes;
111 }
112
scatterwalk_aligned(struct scatter_walk * walk,unsigned int alignmask)113 static inline unsigned int scatterwalk_aligned(struct scatter_walk *walk,
114 unsigned int alignmask)
115 {
116 return !(walk->offset & alignmask);
117 }
118
scatterwalk_page(struct scatter_walk * walk)119 static inline struct page *scatterwalk_page(struct scatter_walk *walk)
120 {
121 return sg_page(walk->sg) + (walk->offset >> PAGE_SHIFT);
122 }
123
scatterwalk_unmap(void * vaddr,int out)124 static inline void scatterwalk_unmap(void *vaddr, int out)
125 {
126 crypto_kunmap(vaddr, out);
127 }
128
129 void scatterwalk_start(struct scatter_walk *walk, struct scatterlist *sg);
130 void scatterwalk_copychunks(void *buf, struct scatter_walk *walk,
131 size_t nbytes, int out);
132 void *scatterwalk_map(struct scatter_walk *walk, int out);
133 void scatterwalk_done(struct scatter_walk *walk, int out, int more);
134
135 void scatterwalk_map_and_copy(void *buf, struct scatterlist *sg,
136 unsigned int start, unsigned int nbytes, int out);
137
138 #endif /* _CRYPTO_SCATTERWALK_H */
139