mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-10-30 08:02:30 +00:00
5fa0fea274
This patch adds the function scatterwalk_map_and_copy which reads or writes a chunk of data from a scatterlist at a given offset. It will be used by authenc which would read/write the authentication data at the end of the cipher/plain text. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
80 lines
2.4 KiB
C
80 lines
2.4 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 <linux/scatterlist.h>
|
|
|
|
#include "internal.h"
|
|
|
|
static inline struct scatterlist *sg_next(struct scatterlist *sg)
|
|
{
|
|
return (++sg)->length ? sg : (void *)sg->page;
|
|
}
|
|
|
|
static inline unsigned long scatterwalk_samebuf(struct scatter_walk *walk_in,
|
|
struct scatter_walk *walk_out)
|
|
{
|
|
return !(((walk_in->sg->page - walk_out->sg->page) << PAGE_SHIFT) +
|
|
(int)(walk_in->offset - walk_out->offset));
|
|
}
|
|
|
|
static inline unsigned int scatterwalk_pagelen(struct scatter_walk *walk)
|
|
{
|
|
unsigned int len = walk->sg->offset + walk->sg->length - walk->offset;
|
|
unsigned int len_this_page = offset_in_page(~walk->offset) + 1;
|
|
return len_this_page > len ? len : len_this_page;
|
|
}
|
|
|
|
static inline unsigned int scatterwalk_clamp(struct scatter_walk *walk,
|
|
unsigned int nbytes)
|
|
{
|
|
unsigned int len_this_page = scatterwalk_pagelen(walk);
|
|
return nbytes > len_this_page ? len_this_page : nbytes;
|
|
}
|
|
|
|
static inline void scatterwalk_advance(struct scatter_walk *walk,
|
|
unsigned int nbytes)
|
|
{
|
|
walk->offset += nbytes;
|
|
}
|
|
|
|
static inline unsigned int scatterwalk_aligned(struct scatter_walk *walk,
|
|
unsigned int alignmask)
|
|
{
|
|
return !(walk->offset & alignmask);
|
|
}
|
|
|
|
static inline struct page *scatterwalk_page(struct scatter_walk *walk)
|
|
{
|
|
return walk->sg->page + (walk->offset >> PAGE_SHIFT);
|
|
}
|
|
|
|
static inline void scatterwalk_unmap(void *vaddr, int out)
|
|
{
|
|
crypto_kunmap(vaddr, out);
|
|
}
|
|
|
|
void scatterwalk_start(struct scatter_walk *walk, struct scatterlist *sg);
|
|
void 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);
|
|
|
|
void scatterwalk_map_and_copy(void *buf, struct scatterlist *sg,
|
|
unsigned int start, unsigned int nbytes, int out);
|
|
|
|
#endif /* _CRYPTO_SCATTERWALK_H */
|