/* * 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;} static inline struct scatterlist *scatterwalk_sg_next(struct scatterlist *sg){	if (sg_is_last(sg))		return NULL; 	return (++sg)->length ? sg : (void *)sg_page(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); #endif  /* _CRYPTO_SCATTERWALK_H */