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b2ab4a57b0
Unfortunately the generic chaining hasn't been ported to all architectures yet, and notably not s390. So this patch restores the chainging that we've been using previously which does work everywhere. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
123 lines
2.9 KiB
C
123 lines
2.9 KiB
C
/*
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* Cryptographic API.
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*
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* Cipher operations.
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*
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* Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
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* 2002 Adam J. Richter <adam@yggdrasil.com>
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* 2004 Jean-Luc Cooke <jlcooke@certainkey.com>
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the Free
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* Software Foundation; either version 2 of the License, or (at your option)
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* any later version.
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*
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*/
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#include <crypto/scatterwalk.h>
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#include <linux/kernel.h>
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#include <linux/mm.h>
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#include <linux/module.h>
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#include <linux/pagemap.h>
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#include <linux/highmem.h>
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#include <linux/scatterlist.h>
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static inline void memcpy_dir(void *buf, void *sgdata, size_t nbytes, int out)
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{
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void *src = out ? buf : sgdata;
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void *dst = out ? sgdata : buf;
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memcpy(dst, src, nbytes);
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}
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void scatterwalk_start(struct scatter_walk *walk, struct scatterlist *sg)
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{
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walk->sg = sg;
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BUG_ON(!sg->length);
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walk->offset = sg->offset;
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}
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EXPORT_SYMBOL_GPL(scatterwalk_start);
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void *scatterwalk_map(struct scatter_walk *walk, int out)
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{
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return crypto_kmap(scatterwalk_page(walk), out) +
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offset_in_page(walk->offset);
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}
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EXPORT_SYMBOL_GPL(scatterwalk_map);
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static void scatterwalk_pagedone(struct scatter_walk *walk, int out,
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unsigned int more)
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{
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if (out) {
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struct page *page;
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page = sg_page(walk->sg) + ((walk->offset - 1) >> PAGE_SHIFT);
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flush_dcache_page(page);
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}
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if (more) {
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walk->offset += PAGE_SIZE - 1;
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walk->offset &= PAGE_MASK;
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if (walk->offset >= walk->sg->offset + walk->sg->length)
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scatterwalk_start(walk, scatterwalk_sg_next(walk->sg));
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}
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}
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void scatterwalk_done(struct scatter_walk *walk, int out, int more)
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{
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if (!offset_in_page(walk->offset) || !more)
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scatterwalk_pagedone(walk, out, more);
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}
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EXPORT_SYMBOL_GPL(scatterwalk_done);
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void scatterwalk_copychunks(void *buf, struct scatter_walk *walk,
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size_t nbytes, int out)
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{
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for (;;) {
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unsigned int len_this_page = scatterwalk_pagelen(walk);
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u8 *vaddr;
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if (len_this_page > nbytes)
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len_this_page = nbytes;
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vaddr = scatterwalk_map(walk, out);
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memcpy_dir(buf, vaddr, len_this_page, out);
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scatterwalk_unmap(vaddr, out);
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scatterwalk_advance(walk, len_this_page);
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if (nbytes == len_this_page)
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break;
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buf += len_this_page;
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nbytes -= len_this_page;
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scatterwalk_pagedone(walk, out, 1);
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}
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}
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EXPORT_SYMBOL_GPL(scatterwalk_copychunks);
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void scatterwalk_map_and_copy(void *buf, struct scatterlist *sg,
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unsigned int start, unsigned int nbytes, int out)
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{
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struct scatter_walk walk;
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unsigned int offset = 0;
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for (;;) {
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scatterwalk_start(&walk, sg);
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if (start < offset + sg->length)
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break;
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offset += sg->length;
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sg = scatterwalk_sg_next(sg);
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}
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scatterwalk_advance(&walk, start - offset);
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scatterwalk_copychunks(buf, &walk, nbytes, out);
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scatterwalk_done(&walk, out, 0);
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}
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EXPORT_SYMBOL_GPL(scatterwalk_map_and_copy);
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