/* * 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 <linux/scatterlist.h> #include "internal.h" static inline struct scatterlist *sg_next(struct scatterlist *sg) { return (++sg)->length ? sg : (void *)sg->page; } static inline unsigned long scatterwalk_samebuf(struct scatter_walk *walk_in, struct scatter_walk *walk_out) { return !(((walk_in->sg->page - walk_out->sg->page) << PAGE_SHIFT) + (int)(walk_in->offset - walk_out->offset)); } 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 walk->sg->page + (walk->offset >> PAGE_SHIFT); } static inline void scatterwalk_unmap(void *vaddr, int out) { crypto_kunmap(vaddr, out); } void scatterwalk_start(struct scatter_walk *walk, struct scatterlist *sg); void 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 */