1/* 2 * Cryptographic scatter and gather helpers. 3 * 4 * Copyright (c) 2002 James Morris <jmorris@intercode.com.au> 5 * Copyright (c) 2002 Adam J. Richter <adam@yggdrasil.com> 6 * Copyright (c) 2004 Jean-Luc Cooke <jlcooke@certainkey.com> 7 * Copyright (c) 2007 Herbert Xu <herbert@gondor.apana.org.au> 8 * 9 * This program is free software; you can redistribute it and/or modify it 10 * under the terms of the GNU General Public License as published by the Free 11 * Software Foundation; either version 2 of the License, or (at your option) 12 * any later version. 13 * 14 */ 15 16#ifndef _CRYPTO_SCATTERWALK_H 17#define _CRYPTO_SCATTERWALK_H 18 19#include <asm/kmap_types.h> 20#include <crypto/algapi.h> 21#include <linux/hardirq.h> 22#include <linux/highmem.h> 23#include <linux/kernel.h> 24#include <linux/mm.h> 25#include <linux/scatterlist.h> 26#include <linux/sched.h> 27 28static inline enum km_type crypto_kmap_type(int out) 29{ 30 enum km_type type; 31 32 if (in_softirq()) 33 type = out * (KM_SOFTIRQ1 - KM_SOFTIRQ0) + KM_SOFTIRQ0; 34 else 35 type = out * (KM_USER1 - KM_USER0) + KM_USER0; 36 37 return type; 38} 39 40static inline void *crypto_kmap(struct page *page, int out) 41{ 42 return kmap_atomic(page, crypto_kmap_type(out)); 43} 44 45static inline void crypto_kunmap(void *vaddr, int out) 46{ 47 kunmap_atomic(vaddr, crypto_kmap_type(out)); 48} 49 50static inline void crypto_yield(u32 flags) 51{ 52 if (flags & CRYPTO_TFM_REQ_MAY_SLEEP) 53 cond_resched(); 54} 55 56static inline void scatterwalk_sg_chain(struct scatterlist *sg1, int num, 57 struct scatterlist *sg2) 58{ 59 sg_set_page(&sg1[num - 1], (void *)sg2, 0, 0); 60 sg1[num - 1].page_link &= ~0x02; 61} 62 63static inline struct scatterlist *scatterwalk_sg_next(struct scatterlist *sg) 64{ 65 if (sg_is_last(sg)) 66 return NULL; 67 68 return (++sg)->length ? sg : (void *)sg_page(sg); 69} 70 71static inline unsigned long scatterwalk_samebuf(struct scatter_walk *walk_in, 72 struct scatter_walk *walk_out) 73{ 74 return !(((sg_page(walk_in->sg) - sg_page(walk_out->sg)) << PAGE_SHIFT) + 75 (int)(walk_in->offset - walk_out->offset)); 76} 77 78static inline unsigned int scatterwalk_pagelen(struct scatter_walk *walk) 79{ 80 unsigned int len = walk->sg->offset + walk->sg->length - walk->offset; 81 unsigned int len_this_page = offset_in_page(~walk->offset) + 1; 82 return len_this_page > len ? len : len_this_page; 83} 84 85static inline unsigned int scatterwalk_clamp(struct scatter_walk *walk, 86 unsigned int nbytes) 87{ 88 unsigned int len_this_page = scatterwalk_pagelen(walk); 89 return nbytes > len_this_page ? len_this_page : nbytes; 90} 91 92static inline void scatterwalk_advance(struct scatter_walk *walk, 93 unsigned int nbytes) 94{ 95 walk->offset += nbytes; 96} 97 98static inline unsigned int scatterwalk_aligned(struct scatter_walk *walk, 99 unsigned int alignmask) 100{ 101 return !(walk->offset & alignmask); 102} 103 104static inline struct page *scatterwalk_page(struct scatter_walk *walk) 105{ 106 return sg_page(walk->sg) + (walk->offset >> PAGE_SHIFT); 107} 108 109static inline void scatterwalk_unmap(void *vaddr, int out) 110{ 111 crypto_kunmap(vaddr, out); 112} 113 114void scatterwalk_start(struct scatter_walk *walk, struct scatterlist *sg); 115void scatterwalk_copychunks(void *buf, struct scatter_walk *walk, 116 size_t nbytes, int out); 117void *scatterwalk_map(struct scatter_walk *walk, int out); 118void scatterwalk_done(struct scatter_walk *walk, int out, int more); 119 120void scatterwalk_map_and_copy(void *buf, struct scatterlist *sg, 121 unsigned int start, unsigned int nbytes, int out); 122 123#endif /* _CRYPTO_SCATTERWALK_H */ 124