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https://github.com/torvalds/linux.git
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Thomas Gleixner
2874c5fd28
Based on 1 normalized pattern(s): 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 extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner <[email protected]> Reviewed-by: Allison Randal <[email protected]> Cc: [email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
94 lines
2.0 KiB
C
94 lines
2.0 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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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 <[email protected]>
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* 2002 Adam J. Richter <[email protected]>
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* 2004 Jean-Luc Cooke <[email protected]>
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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/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_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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if (out != 2) {
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vaddr = scatterwalk_map(walk);
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memcpy_dir(buf, vaddr, len_this_page, out);
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scatterwalk_unmap(vaddr);
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}
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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, 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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struct scatterlist tmp[2];
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if (!nbytes)
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return;
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sg = scatterwalk_ffwd(tmp, sg, start);
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scatterwalk_start(&walk, sg);
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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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struct scatterlist *scatterwalk_ffwd(struct scatterlist dst[2],
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struct scatterlist *src,
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unsigned int len)
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{
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for (;;) {
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if (!len)
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return src;
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if (src->length > len)
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break;
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len -= src->length;
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src = sg_next(src);
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}
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sg_init_table(dst, 2);
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sg_set_page(dst, sg_page(src), src->length - len, src->offset + len);
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scatterwalk_crypto_chain(dst, sg_next(src), 2);
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return dst;
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}
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EXPORT_SYMBOL_GPL(scatterwalk_ffwd);
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