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Diffstat (limited to 'include/crypto/scatterwalk.h')
| -rw-r--r-- | include/crypto/scatterwalk.h | 120 |
1 files changed, 120 insertions, 0 deletions
diff --git a/include/crypto/scatterwalk.h b/include/crypto/scatterwalk.h new file mode 100644 index 000000000..a66c127a2 --- /dev/null +++ b/include/crypto/scatterwalk.h @@ -0,0 +1,120 @@ +/* + * Cryptographic scatter and gather helpers. + * + * Copyright (c) 2002 James Morris <jmorris@intercode.com.au> + * Copyright (c) 2002 Adam J. Richter <adam@yggdrasil.com> + * Copyright (c) 2004 Jean-Luc Cooke <jlcooke@certainkey.com> + * Copyright (c) 2007 Herbert Xu <herbert@gondor.apana.org.au> + * + * 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. + * + */ + +#ifndef _CRYPTO_SCATTERWALK_H +#define _CRYPTO_SCATTERWALK_H + +#include <crypto/algapi.h> +#include <linux/highmem.h> +#include <linux/kernel.h> +#include <linux/scatterlist.h> + +static inline void scatterwalk_crypto_chain(struct scatterlist *head, + struct scatterlist *sg, int num) +{ + if (sg) + sg_chain(head, num, sg); + else + sg_mark_end(head); +} + +static inline unsigned int scatterwalk_pagelen(struct scatter_walk *walk) +{ + unsigned int len = walk->sg->offset + walk->sg->length - walk->offset; + unsigned int len_this_page = offset_in_page(~walk->offset) + 1; + return len_this_page > len ? len : len_this_page; +} + +static inline unsigned int scatterwalk_clamp(struct scatter_walk *walk, + unsigned int nbytes) +{ + unsigned int len_this_page = scatterwalk_pagelen(walk); + return nbytes > len_this_page ? len_this_page : nbytes; +} + +static inline void scatterwalk_advance(struct scatter_walk *walk, + unsigned int nbytes) +{ + walk->offset += nbytes; +} + +static inline unsigned int scatterwalk_aligned(struct scatter_walk *walk, + unsigned int alignmask) +{ + return !(walk->offset & alignmask); +} + +static inline struct page *scatterwalk_page(struct scatter_walk *walk) +{ + return sg_page(walk->sg) + (walk->offset >> PAGE_SHIFT); +} + +static inline void scatterwalk_unmap(void *vaddr) +{ + kunmap_atomic(vaddr); +} + +static inline void scatterwalk_start(struct scatter_walk *walk, + struct scatterlist *sg) +{ + walk->sg = sg; + walk->offset = sg->offset; +} + +static inline void *scatterwalk_map(struct scatter_walk *walk) +{ + return kmap_atomic(scatterwalk_page(walk)) + + offset_in_page(walk->offset); +} + +static inline void scatterwalk_pagedone(struct scatter_walk *walk, int out, + unsigned int more) +{ + if (out) { + struct page *page; + + page = sg_page(walk->sg) + ((walk->offset - 1) >> PAGE_SHIFT); + /* Test ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE first as + * PageSlab cannot be optimised away per se due to + * use of volatile pointer. + */ + if (ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE && !PageSlab(page)) + flush_dcache_page(page); + } + + if (more && walk->offset >= walk->sg->offset + walk->sg->length) + scatterwalk_start(walk, sg_next(walk->sg)); +} + +static inline void scatterwalk_done(struct scatter_walk *walk, int out, + int more) +{ + if (!more || walk->offset >= walk->sg->offset + walk->sg->length || + !(walk->offset & (PAGE_SIZE - 1))) + scatterwalk_pagedone(walk, out, more); +} + +void scatterwalk_copychunks(void *buf, struct scatter_walk *walk, + size_t nbytes, int out); +void *scatterwalk_map(struct scatter_walk *walk); + +void scatterwalk_map_and_copy(void *buf, struct scatterlist *sg, + unsigned int start, unsigned int nbytes, int out); + +struct scatterlist *scatterwalk_ffwd(struct scatterlist dst[2], + struct scatterlist *src, + unsigned int len); + +#endif /* _CRYPTO_SCATTERWALK_H */ |