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110 lines
2.9 KiB
110 lines
2.9 KiB
/* SPDX-License-Identifier: GPL-2.0-or-later */ |
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/* |
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* Cryptographic scatter and gather helpers. |
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* |
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* Copyright (c) 2002 James Morris <[email protected]> |
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* Copyright (c) 2002 Adam J. Richter <[email protected]> |
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* Copyright (c) 2004 Jean-Luc Cooke <[email protected]> |
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* Copyright (c) 2007 Herbert Xu <[email protected]> |
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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 <crypto/algapi.h> |
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#include <linux/highmem.h> |
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#include <linux/kernel.h> |
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#include <linux/scatterlist.h> |
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static inline void scatterwalk_crypto_chain(struct scatterlist *head, |
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struct scatterlist *sg, int num) |
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{ |
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if (sg) |
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sg_chain(head, num, sg); |
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else |
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sg_mark_end(head); |
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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 sg_page(walk->sg) + (walk->offset >> PAGE_SHIFT); |
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} |
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static inline void scatterwalk_unmap(void *vaddr) |
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{ |
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kunmap_atomic(vaddr); |
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} |
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static inline void scatterwalk_start(struct scatter_walk *walk, |
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struct scatterlist *sg) |
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{ |
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walk->sg = sg; |
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walk->offset = sg->offset; |
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} |
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static inline void *scatterwalk_map(struct scatter_walk *walk) |
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{ |
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return kmap_atomic(scatterwalk_page(walk)) + |
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offset_in_page(walk->offset); |
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} |
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static inline 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 && walk->offset >= walk->sg->offset + walk->sg->length) |
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scatterwalk_start(walk, sg_next(walk->sg)); |
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} |
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static inline void scatterwalk_done(struct scatter_walk *walk, int out, |
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int more) |
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{ |
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if (!more || walk->offset >= walk->sg->offset + walk->sg->length || |
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!(walk->offset & (PAGE_SIZE - 1))) |
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scatterwalk_pagedone(walk, out, more); |
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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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void *scatterwalk_map(struct scatter_walk *walk); |
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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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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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#endif /* _CRYPTO_SCATTERWALK_H */
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