Edit File: scatterwalk.h
/* * 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 <asm/kmap_types.h> #include <crypto/algapi.h> #include <linux/hardirq.h> #include <linux/highmem.h> #include <linux/kernel.h> #include <linux/mm.h> #include <linux/scatterlist.h> #include <linux/sched.h> static inline void crypto_yield(u32 flags) { if (flags & CRYPTO_TFM_REQ_MAY_SLEEP) cond_resched(); } static inline void scatterwalk_sg_chain(struct scatterlist *sg1, int num, struct scatterlist *sg2) { sg_set_page(&sg1[num - 1], (void *)sg2, 0, 0); sg1[num - 1].page_link &= ~0x02; sg1[num - 1].page_link |= 0x01; } static inline struct scatterlist *scatterwalk_sg_next(struct scatterlist *sg) { if (sg_is_last(sg)) return NULL; return (++sg)->length ? sg : sg_chain_ptr(sg); } static inline void scatterwalk_crypto_chain(struct scatterlist *head, struct scatterlist *sg, int chain, int num) { if (chain) { head->length += sg->length; sg = scatterwalk_sg_next(sg); } if (sg) scatterwalk_sg_chain(head, num, sg); else sg_mark_end(head); } static inline unsigned long scatterwalk_samebuf(struct scatter_walk *walk_in, struct scatter_walk *walk_out) { return !(((sg_page(walk_in->sg) - sg_page(walk_out->sg)) << 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 sg_page(walk->sg) + (walk->offset >> PAGE_SHIFT); } static inline void scatterwalk_unmap(void *vaddr) { kunmap_atomic(vaddr); } 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); void scatterwalk_done(struct scatter_walk *walk, int out, int more); 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 */