9547737799
The VIA Padlock device requires the input and output buffers to be aligned on 16-byte boundaries. This patch adds the alignmask attribute for low-level cipher implementations to indicate their alignment requirements. The mid-level crypt() function will copy the input/output buffers if they are not aligned correctly before they are passed to the low-level implementation. Strictly speaking, some of the software implementations require the buffers to be aligned on 4-byte boundaries as they do 32-bit loads. However, it is not clear whether it is better to copy the buffers or pay the penalty for unaligned loads/stores. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
70 lines
2.0 KiB
C
70 lines
2.0 KiB
C
/*
|
|
* Cryptographic API.
|
|
*
|
|
* Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
|
|
* Copyright (c) 2002 Adam J. Richter <adam@yggdrasil.com>
|
|
* Copyright (c) 2004 Jean-Luc Cooke <jlcooke@certainkey.com>
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify it
|
|
* under the terms of the GNU General Public License as published by the Free
|
|
* Software Foundation; either version 2 of the License, or (at your option)
|
|
* any later version.
|
|
*
|
|
*/
|
|
|
|
#ifndef _CRYPTO_SCATTERWALK_H
|
|
#define _CRYPTO_SCATTERWALK_H
|
|
#include <linux/mm.h>
|
|
#include <asm/scatterlist.h>
|
|
|
|
struct scatter_walk {
|
|
struct scatterlist *sg;
|
|
struct page *page;
|
|
void *data;
|
|
unsigned int len_this_page;
|
|
unsigned int len_this_segment;
|
|
unsigned int offset;
|
|
};
|
|
|
|
/* Define sg_next is an inline routine now in case we want to change
|
|
scatterlist to a linked list later. */
|
|
static inline struct scatterlist *sg_next(struct scatterlist *sg)
|
|
{
|
|
return sg + 1;
|
|
}
|
|
|
|
static inline int scatterwalk_samebuf(struct scatter_walk *walk_in,
|
|
struct scatter_walk *walk_out)
|
|
{
|
|
return walk_in->page == walk_out->page &&
|
|
walk_in->offset == walk_out->offset;
|
|
}
|
|
|
|
static inline unsigned int scatterwalk_clamp(struct scatter_walk *walk,
|
|
unsigned int nbytes)
|
|
{
|
|
return nbytes > walk->len_this_page ? walk->len_this_page : nbytes;
|
|
}
|
|
|
|
static inline void scatterwalk_advance(struct scatter_walk *walk,
|
|
unsigned int nbytes)
|
|
{
|
|
walk->data += nbytes;
|
|
walk->offset += nbytes;
|
|
walk->len_this_page -= nbytes;
|
|
walk->len_this_segment -= nbytes;
|
|
}
|
|
|
|
static inline unsigned int scatterwalk_aligned(struct scatter_walk *walk,
|
|
unsigned int alignmask)
|
|
{
|
|
return !(walk->offset & alignmask);
|
|
}
|
|
|
|
void scatterwalk_start(struct scatter_walk *walk, struct scatterlist *sg);
|
|
int scatterwalk_copychunks(void *buf, struct scatter_walk *walk, size_t nbytes, int out);
|
|
void scatterwalk_map(struct scatter_walk *walk, int out);
|
|
void scatterwalk_done(struct scatter_walk *walk, int out, int more);
|
|
|
|
#endif /* _CRYPTO_SCATTERWALK_H */
|