115 lines
2.8 KiB
C
115 lines
2.8 KiB
C
/*
|
|
* Cryptographic API.
|
|
*
|
|
* Cipher operations.
|
|
*
|
|
* Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
|
|
* 2002 Adam J. Richter <adam@yggdrasil.com>
|
|
* 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.
|
|
*
|
|
*/
|
|
#include <linux/kernel.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/pagemap.h>
|
|
#include <linux/highmem.h>
|
|
#include <asm/scatterlist.h>
|
|
#include "internal.h"
|
|
#include "scatterwalk.h"
|
|
|
|
enum km_type crypto_km_types[] = {
|
|
KM_USER0,
|
|
KM_USER1,
|
|
KM_SOFTIRQ0,
|
|
KM_SOFTIRQ1,
|
|
};
|
|
|
|
static void memcpy_dir(void *buf, void *sgdata, size_t nbytes, int out)
|
|
{
|
|
if (out)
|
|
memcpy(sgdata, buf, nbytes);
|
|
else
|
|
memcpy(buf, sgdata, nbytes);
|
|
}
|
|
|
|
void scatterwalk_start(struct scatter_walk *walk, struct scatterlist *sg)
|
|
{
|
|
unsigned int rest_of_page;
|
|
|
|
walk->sg = sg;
|
|
|
|
walk->page = sg->page;
|
|
walk->len_this_segment = sg->length;
|
|
|
|
BUG_ON(!sg->length);
|
|
|
|
rest_of_page = PAGE_CACHE_SIZE - (sg->offset & (PAGE_CACHE_SIZE - 1));
|
|
walk->len_this_page = min(sg->length, rest_of_page);
|
|
walk->offset = sg->offset;
|
|
}
|
|
|
|
void scatterwalk_map(struct scatter_walk *walk, int out)
|
|
{
|
|
walk->data = crypto_kmap(walk->page, out) + walk->offset;
|
|
}
|
|
|
|
static inline void scatterwalk_unmap(struct scatter_walk *walk, int out)
|
|
{
|
|
/* walk->data may be pointing the first byte of the next page;
|
|
however, we know we transfered at least one byte. So,
|
|
walk->data - 1 will be a virtual address in the mapped page. */
|
|
crypto_kunmap(walk->data - 1, out);
|
|
}
|
|
|
|
static void scatterwalk_pagedone(struct scatter_walk *walk, int out,
|
|
unsigned int more)
|
|
{
|
|
if (out)
|
|
flush_dcache_page(walk->page);
|
|
|
|
if (more) {
|
|
walk->len_this_segment -= walk->len_this_page;
|
|
|
|
if (walk->len_this_segment) {
|
|
walk->page++;
|
|
walk->len_this_page = min(walk->len_this_segment,
|
|
(unsigned)PAGE_CACHE_SIZE);
|
|
walk->offset = 0;
|
|
}
|
|
else
|
|
scatterwalk_start(walk, sg_next(walk->sg));
|
|
}
|
|
}
|
|
|
|
void scatterwalk_done(struct scatter_walk *walk, int out, int more)
|
|
{
|
|
scatterwalk_unmap(walk, out);
|
|
if (walk->len_this_page == 0 || !more)
|
|
scatterwalk_pagedone(walk, out, more);
|
|
}
|
|
|
|
/*
|
|
* Do not call this unless the total length of all of the fragments
|
|
* has been verified as multiple of the block size.
|
|
*/
|
|
int scatterwalk_copychunks(void *buf, struct scatter_walk *walk,
|
|
size_t nbytes, int out)
|
|
{
|
|
while (nbytes > walk->len_this_page) {
|
|
memcpy_dir(buf, walk->data, walk->len_this_page, out);
|
|
buf += walk->len_this_page;
|
|
nbytes -= walk->len_this_page;
|
|
|
|
scatterwalk_unmap(walk, out);
|
|
scatterwalk_pagedone(walk, out, 1);
|
|
scatterwalk_map(walk, out);
|
|
}
|
|
|
|
memcpy_dir(buf, walk->data, nbytes, out);
|
|
return nbytes;
|
|
}
|