Orange Pi5 kernel

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * 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>
 */
 
#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;
<------>struct scatterlist tmp[2];
 
<------>if (!nbytes)
<------><------>return;
 
<------>sg = scatterwalk_ffwd(tmp, sg, start);
 
<------>scatterwalk_start(&walk, sg);
<------>scatterwalk_copychunks(buf, &walk, nbytes, out);
<------>scatterwalk_done(&walk, out, 0);
}
EXPORT_SYMBOL_GPL(scatterwalk_map_and_copy);
 
struct scatterlist *scatterwalk_ffwd(struct scatterlist dst[2],
<------><------><------><------>     struct scatterlist *src,
<------><------><------><------>     unsigned int len)
{
<------>for (;;) {
<------><------>if (!len)
<------><------><------>return src;
 
<------><------>if (src->length > len)
<------><------><------>break;
 
<------><------>len -= src->length;
<------><------>src = sg_next(src);
<------>}
 
<------>sg_init_table(dst, 2);
<------>sg_set_page(dst, sg_page(src), src->length - len, src->offset + len);
<------>scatterwalk_crypto_chain(dst, sg_next(src), 2);
 
<------>return dst;
}
EXPORT_SYMBOL_GPL(scatterwalk_ffwd);