Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / include / crypto / scatterwalk.h
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
28 static 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);
32         sg1[num - 1].page_link &= ~0x02;
33         sg1[num - 1].page_link |= 0x01;
34 }
35
36 static 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;
42                 sg = sg_next(sg);
43         }
44
45         if (sg)
46                 scatterwalk_sg_chain(head, num, sg);
47         else
48                 sg_mark_end(head);
49 }
50
51 static inline unsigned long scatterwalk_samebuf(struct scatter_walk *walk_in,
52                                                 struct scatter_walk *walk_out)
53 {
54         return !(((sg_page(walk_in->sg) - sg_page(walk_out->sg)) << PAGE_SHIFT) +
55                  (int)(walk_in->offset - walk_out->offset));
56 }
57
58 static 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;
63 }
64
65 static inline unsigned int scatterwalk_clamp(struct scatter_walk *walk,
66                                              unsigned int nbytes)
67 {
68         unsigned int len_this_page = scatterwalk_pagelen(walk);
69         return nbytes > len_this_page ? len_this_page : nbytes;
70 }
71
72 static inline void scatterwalk_advance(struct scatter_walk *walk,
73                                        unsigned int nbytes)
74 {
75         walk->offset += nbytes;
76 }
77
78 static inline unsigned int scatterwalk_aligned(struct scatter_walk *walk,
79                                                unsigned int alignmask)
80 {
81         return !(walk->offset & alignmask);
82 }
83
84 static inline struct page *scatterwalk_page(struct scatter_walk *walk)
85 {
86         return sg_page(walk->sg) + (walk->offset >> PAGE_SHIFT);
87 }
88
89 static inline void scatterwalk_unmap(void *vaddr)
90 {
91         kunmap_atomic(vaddr);
92 }
93
94 void scatterwalk_start(struct scatter_walk *walk, struct scatterlist *sg);
95 void scatterwalk_copychunks(void *buf, struct scatter_walk *walk,
96                             size_t nbytes, int out);
97 void *scatterwalk_map(struct scatter_walk *walk);
98 void scatterwalk_done(struct scatter_walk *walk, int out, int more);
99
100 void scatterwalk_map_and_copy(void *buf, struct scatterlist *sg,
101                               unsigned int start, unsigned int nbytes, int out);
102
103 int scatterwalk_bytes_sglen(struct scatterlist *sg, int num_bytes);
104
105 #endif  /* _CRYPTO_SCATTERWALK_H */