linux-imx

/*

 * Symmetric key cipher operations.

 *

 * Generic encrypt/decrypt wrapper for ciphers, handles operations across

 * multiple page boundaries by using temporary blocks.  In user context,

 * the kernel is given a chance to schedule us once per page.

 *

 * Copyright (c) 2015 Herbert Xu <herbert@gondor.apana.org.au>

 *

 * 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/internal/aead.h>

#include <crypto/internal/skcipher.h>

#include <crypto/scatterwalk.h>

#include <linux/bug.h>

#include <linux/cryptouser.h>

#include <linux/compiler.h>

#include <linux/list.h>

#include <linux/module.h>

#include <linux/rtnetlink.h>

#include <linux/seq_file.h>

#include <net/netlink.h>

​

#include "internal.h"

​

enum {

    SKCIPHER_WALK_PHYS = 1 << 0,

    SKCIPHER_WALK_SLOW = 1 << 1,

    SKCIPHER_WALK_COPY = 1 << 2,

    SKCIPHER_WALK_DIFF = 1 << 3,

    SKCIPHER_WALK_SLEEP = 1 << 4,

};

​

struct skcipher_walk_buffer {

    struct list_head entry;

    struct scatter_walk dst;

    unsigned int len;

    u8 *data;

    u8 buffer[];

};

​

static int skcipher_walk_next(struct skcipher_walk *walk);

​

static inline void skcipher_unmap(struct scatter_walk *walk, void *vaddr)

{

    if (PageHighMem(scatterwalk_page(walk)))

        kunmap_atomic(vaddr);

}

​

static inline void *skcipher_map(struct scatter_walk *walk)

{

    struct page *page = scatterwalk_page(walk);

​

    return (PageHighMem(page) ? kmap_atomic(page) : page_address(page)) +

           offset_in_page(walk->offset);

}

​

static inline void skcipher_map_src(struct skcipher_walk *walk)