/* * Cryptographic API. * * 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> * * 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 <linux/mm.h> #include <asm/scatterlist.h> struct scatter_walk { struct scatterlist *sg; struct page *page; void *data; unsigned int len_this_page; unsigned int len_this_segment; unsigned int offset; }; /* Define sg_next is an inline routine now in case we want to change scatterlist to a linked list later. */ static inline struct scatterlist *sg_next(struct scatterlist *sg) { return sg + 1; } static inline int scatterwalk_samebuf(struct scatter_walk *walk_in, struct scatter_walk *walk_out) { return walk_in->page == walk_out->page && walk_in->offset == walk_out->offset; } static inline unsigned int scatterwalk_clamp(struct scatter_walk *walk, unsigned int nbytes) { return nbytes > walk->len_this_page ? walk->len_this_page : nbytes; } static inline void scatterwalk_advance(struct scatter_walk *walk, unsigned int nbytes) { walk->data += nbytes; walk->offset += nbytes; walk->len_this_page -= nbytes; walk->len_this_segment -= nbytes; } static inline unsigned int scatterwalk_aligned(struct scatter_walk *walk, unsigned int alignmask) { return !(walk->offset & alignmask); } void scatterwalk_start(struct scatter_walk *walk, struct scatterlist *sg); int scatterwalk_copychunks(void *buf, struct scatter_walk *walk, size_t nbytes, int out); void scatterwalk_map(struct scatter_walk *walk, int out); void scatterwalk_done(struct scatter_walk *walk, int out, int more); #endif /* _CRYPTO_SCATTERWALK_H */