linux-imx

/*

 * 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 <crypto/scatterwalk.h>

#include <linux/kernel.h>

#include <linux/mm.h>

#include <linux/module.h>

#include <linux/scatterlist.h>

​

static inline void memcpy_dir(void *buf, void *sgdata, size_t nbytes, int out)

{

    void *src = out ? buf : sgdata;

    void *dst = out ? sgdata : buf;

​

    memcpy(dst, src, nbytes);

}

​

void scatterwalk_copychunks(void *buf, struct scatter_walk *walk,

                size_t nbytes, int out)

{

    for (;;) {

        unsigned int len_this_page = scatterwalk_pagelen(walk);

        u8 *vaddr;

​

        if (len_this_page > nbytes)

            len_this_page = nbytes;

​

        if (out != 2) {

            vaddr = scatterwalk_map(walk);

            memcpy_dir(buf, vaddr, len_this_page, out);

            scatterwalk_unmap(vaddr);

        }

​

        scatterwalk_advance(walk, len_this_page);

​

        if (nbytes == len_this_page)

            break;

​

        buf += len_this_page;

        nbytes -= len_this_page;

​

        scatterwalk_pagedone(walk, out & 1, 1);

    }

}

EXPORT_SYMBOL_GPL(scatterwalk_copychunks);

​

void scatterwalk_map_and_copy(void *buf, struct scatterlist *sg,

                  unsigned int start, unsigned int nbytes, int out)

{

    struct scatter_walk walk;