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git.proxmox.com Git - mirror_ubuntu-artful-kernel.git/blob - crypto/scatterwalk.c
6 * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
7 * 2002 Adam J. Richter <adam@yggdrasil.com>
8 * 2004 Jean-Luc Cooke <jlcooke@certainkey.com>
10 * This program is free software; you can redistribute it and/or modify it
11 * under the terms of the GNU General Public License as published by the Free
12 * Software Foundation; either version 2 of the License, or (at your option)
16 #include <linux/kernel.h>
18 #include <linux/module.h>
19 #include <linux/pagemap.h>
20 #include <linux/highmem.h>
21 #include <linux/scatterlist.h>
24 #include "scatterwalk.h"
26 enum km_type crypto_km_types
[] = {
32 EXPORT_SYMBOL_GPL(crypto_km_types
);
34 static inline void memcpy_dir(void *buf
, void *sgdata
, size_t nbytes
, int out
)
36 void *src
= out
? buf
: sgdata
;
37 void *dst
= out
? sgdata
: buf
;
39 memcpy(dst
, src
, nbytes
);
42 void scatterwalk_start(struct scatter_walk
*walk
, struct scatterlist
*sg
)
48 walk
->offset
= sg
->offset
;
50 EXPORT_SYMBOL_GPL(scatterwalk_start
);
52 void *scatterwalk_map(struct scatter_walk
*walk
, int out
)
54 return crypto_kmap(scatterwalk_page(walk
), out
) +
55 offset_in_page(walk
->offset
);
57 EXPORT_SYMBOL_GPL(scatterwalk_map
);
59 static void scatterwalk_pagedone(struct scatter_walk
*walk
, int out
,
65 page
= walk
->sg
->page
+ ((walk
->offset
- 1) >> PAGE_SHIFT
);
66 flush_dcache_page(page
);
70 walk
->offset
+= PAGE_SIZE
- 1;
71 walk
->offset
&= PAGE_MASK
;
72 if (walk
->offset
>= walk
->sg
->offset
+ walk
->sg
->length
)
73 scatterwalk_start(walk
, sg_next(walk
->sg
));
77 void scatterwalk_done(struct scatter_walk
*walk
, int out
, int more
)
79 if (!offset_in_page(walk
->offset
) || !more
)
80 scatterwalk_pagedone(walk
, out
, more
);
82 EXPORT_SYMBOL_GPL(scatterwalk_done
);
84 void scatterwalk_copychunks(void *buf
, struct scatter_walk
*walk
,
85 size_t nbytes
, int out
)
88 unsigned int len_this_page
= scatterwalk_pagelen(walk
);
91 if (len_this_page
> nbytes
)
92 len_this_page
= nbytes
;
94 vaddr
= scatterwalk_map(walk
, out
);
95 memcpy_dir(buf
, vaddr
, len_this_page
, out
);
96 scatterwalk_unmap(vaddr
, out
);
98 scatterwalk_advance(walk
, len_this_page
);
100 if (nbytes
== len_this_page
)
103 buf
+= len_this_page
;
104 nbytes
-= len_this_page
;
106 scatterwalk_pagedone(walk
, out
, 1);
109 EXPORT_SYMBOL_GPL(scatterwalk_copychunks
);
111 void scatterwalk_map_and_copy(void *buf
, struct scatterlist
*sg
,
112 unsigned int start
, unsigned int nbytes
, int out
)
114 struct scatter_walk walk
;
115 unsigned int offset
= 0;
118 scatterwalk_start(&walk
, sg
);
120 if (start
< offset
+ sg
->length
)
123 offset
+= sg
->length
;
127 scatterwalk_advance(&walk
, start
- offset
);
128 scatterwalk_copychunks(buf
, &walk
, nbytes
, out
);
129 scatterwalk_done(&walk
, out
, 0);
131 EXPORT_SYMBOL_GPL(scatterwalk_map_and_copy
);