1 /* 2 * Cryptographic API. 3 * 4 * Cipher operations. 5 * 6 * Copyright (c) 2002 James Morris <jmorris@intercode.com.au> 7 * 2002 Adam J. Richter <adam@yggdrasil.com> 8 * 2004 Jean-Luc Cooke <jlcooke@certainkey.com> 9 * 10 * This program is free software; you can redistribute it and/or modify it 11 * under the terms of the GNU General Public License as published by the Free 12 * Software Foundation; either version 2 of the License, or (at your option) 13 * any later version. 14 * 15 */ 16 #include <linux/kernel.h> 17 #include <linux/mm.h> 18 #include <linux/module.h> 19 #include <linux/pagemap.h> 20 #include <linux/highmem.h> 21 #include <linux/scatterlist.h> 22 23 #include "internal.h" 24 #include "scatterwalk.h" 25 26 enum km_type crypto_km_types[] = { 27 KM_USER0, 28 KM_USER1, 29 KM_SOFTIRQ0, 30 KM_SOFTIRQ1, 31 }; 32 EXPORT_SYMBOL_GPL(crypto_km_types); 33 34 static inline void memcpy_dir(void *buf, void *sgdata, size_t nbytes, int out) 35 { 36 void *src = out ? buf : sgdata; 37 void *dst = out ? sgdata : buf; 38 39 memcpy(dst, src, nbytes); 40 } 41 42 void scatterwalk_start(struct scatter_walk *walk, struct scatterlist *sg) 43 { 44 walk->sg = sg; 45 46 BUG_ON(!sg->length); 47 48 walk->offset = sg->offset; 49 } 50 EXPORT_SYMBOL_GPL(scatterwalk_start); 51 52 void *scatterwalk_map(struct scatter_walk *walk, int out) 53 { 54 return crypto_kmap(scatterwalk_page(walk), out) + 55 offset_in_page(walk->offset); 56 } 57 EXPORT_SYMBOL_GPL(scatterwalk_map); 58 59 static void scatterwalk_pagedone(struct scatter_walk *walk, int out, 60 unsigned int more) 61 { 62 if (out) 63 flush_dcache_page(scatterwalk_page(walk)); 64 65 if (more) { 66 walk->offset += PAGE_SIZE - 1; 67 walk->offset &= PAGE_MASK; 68 if (walk->offset >= walk->sg->offset + walk->sg->length) 69 scatterwalk_start(walk, sg_next(walk->sg)); 70 } 71 } 72 73 void scatterwalk_done(struct scatter_walk *walk, int out, int more) 74 { 75 if (!offset_in_page(walk->offset) || !more) 76 scatterwalk_pagedone(walk, out, more); 77 } 78 EXPORT_SYMBOL_GPL(scatterwalk_done); 79 80 void scatterwalk_copychunks(void *buf, struct scatter_walk *walk, 81 size_t nbytes, int out) 82 { 83 for (;;) { 84 unsigned int len_this_page = scatterwalk_pagelen(walk); 85 u8 *vaddr; 86 87 if (len_this_page > nbytes) 88 len_this_page = nbytes; 89 90 vaddr = scatterwalk_map(walk, out); 91 memcpy_dir(buf, vaddr, len_this_page, out); 92 scatterwalk_unmap(vaddr, out); 93 94 if (nbytes == len_this_page) 95 break; 96 97 buf += len_this_page; 98 nbytes -= len_this_page; 99 100 scatterwalk_pagedone(walk, out, 1); 101 } 102 103 scatterwalk_advance(walk, nbytes); 104 } 105 EXPORT_SYMBOL_GPL(scatterwalk_copychunks); 106