blob: e79925c474a3a2eb6de0fe120d1e0151acd45530 [file] [log] [blame]
* Cryptographic API.
* Copyright (c) 2002 James Morris <>
* Copyright (c) 2002 Adam J. Richter <>
* Copyright (c) 2004 Jean-Luc Cooke <>
* 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.
#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);