forked from luck/tmp_suning_uos_patched
5fa0fea274
This patch adds the function scatterwalk_map_and_copy which reads or writes a chunk of data from a scatterlist at a given offset. It will be used by authenc which would read/write the authentication data at the end of the cipher/plain text. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
81 lines
2.4 KiB
C
81 lines
2.4 KiB
C
/*
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* Cryptographic API.
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*
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* Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
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* Copyright (c) 2002 Adam J. Richter <adam@yggdrasil.com>
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* Copyright (c) 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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#ifndef _CRYPTO_SCATTERWALK_H
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#define _CRYPTO_SCATTERWALK_H
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#include <linux/mm.h>
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#include <linux/scatterlist.h>
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#include "internal.h"
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static inline struct scatterlist *sg_next(struct scatterlist *sg)
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{
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return (++sg)->length ? sg : (void *)sg->page;
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}
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static inline unsigned long scatterwalk_samebuf(struct scatter_walk *walk_in,
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struct scatter_walk *walk_out)
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{
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return !(((walk_in->sg->page - walk_out->sg->page) << PAGE_SHIFT) +
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(int)(walk_in->offset - walk_out->offset));
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}
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static inline unsigned int scatterwalk_pagelen(struct scatter_walk *walk)
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{
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unsigned int len = walk->sg->offset + walk->sg->length - walk->offset;
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unsigned int len_this_page = offset_in_page(~walk->offset) + 1;
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return len_this_page > len ? len : len_this_page;
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}
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static inline unsigned int scatterwalk_clamp(struct scatter_walk *walk,
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unsigned int nbytes)
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{
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unsigned int len_this_page = scatterwalk_pagelen(walk);
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return nbytes > len_this_page ? len_this_page : nbytes;
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}
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static inline void scatterwalk_advance(struct scatter_walk *walk,
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unsigned int nbytes)
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{
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walk->offset += nbytes;
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}
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static inline unsigned int scatterwalk_aligned(struct scatter_walk *walk,
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unsigned int alignmask)
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{
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return !(walk->offset & alignmask);
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}
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static inline struct page *scatterwalk_page(struct scatter_walk *walk)
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{
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return walk->sg->page + (walk->offset >> PAGE_SHIFT);
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}
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static inline void scatterwalk_unmap(void *vaddr, int out)
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{
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crypto_kunmap(vaddr, out);
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}
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void scatterwalk_start(struct scatter_walk *walk, struct scatterlist *sg);
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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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void *scatterwalk_map(struct scatter_walk *walk, int out);
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void scatterwalk_done(struct scatter_walk *walk, int out, int more);
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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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#endif /* _CRYPTO_SCATTERWALK_H */
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