1 /* 2 * Cryptographic API for the 842 software compression algorithm. 3 * 4 * This program is free software; you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License as published by 6 * the Free Software Foundation; either version 2 of the License, or 7 * (at your option) any later version. 8 * 9 * This program is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 * GNU General Public License for more details. 13 * 14 * Copyright (C) IBM Corporation, 2011-2015 15 * 16 * Original Authors: Robert Jennings <rcj@linux.vnet.ibm.com> 17 * Seth Jennings <sjenning@linux.vnet.ibm.com> 18 * 19 * Rewrite: Dan Streetman <ddstreet@ieee.org> 20 * 21 * This is the software implementation of compression and decompression using 22 * the 842 format. This uses the software 842 library at lib/842/ which is 23 * only a reference implementation, and is very, very slow as compared to other 24 * software compressors. You probably do not want to use this software 25 * compression. If you have access to the PowerPC 842 compression hardware, you 26 * want to use the 842 hardware compression interface, which is at: 27 * drivers/crypto/nx/nx-842-crypto.c 28 */ 29 30 #include <linux/init.h> 31 #include <linux/module.h> 32 #include <linux/crypto.h> 33 #include <linux/sw842.h> 34 35 struct crypto842_ctx { 36 char wmem[SW842_MEM_COMPRESS]; /* working memory for compress */ 37 }; 38 39 static int crypto842_compress(struct crypto_tfm *tfm, 40 const u8 *src, unsigned int slen, 41 u8 *dst, unsigned int *dlen) 42 { 43 struct crypto842_ctx *ctx = crypto_tfm_ctx(tfm); 44 45 return sw842_compress(src, slen, dst, dlen, ctx->wmem); 46 } 47 48 static int crypto842_decompress(struct crypto_tfm *tfm, 49 const u8 *src, unsigned int slen, 50 u8 *dst, unsigned int *dlen) 51 { 52 return sw842_decompress(src, slen, dst, dlen); 53 } 54 55 static struct crypto_alg alg = { 56 .cra_name = "842", 57 .cra_driver_name = "842-generic", 58 .cra_priority = 100, 59 .cra_flags = CRYPTO_ALG_TYPE_COMPRESS, 60 .cra_ctxsize = sizeof(struct crypto842_ctx), 61 .cra_module = THIS_MODULE, 62 .cra_u = { .compress = { 63 .coa_compress = crypto842_compress, 64 .coa_decompress = crypto842_decompress } } 65 }; 66 67 static int __init crypto842_mod_init(void) 68 { 69 return crypto_register_alg(&alg); 70 } 71 module_init(crypto842_mod_init); 72 73 static void __exit crypto842_mod_exit(void) 74 { 75 crypto_unregister_alg(&alg); 76 } 77 module_exit(crypto842_mod_exit); 78 79 MODULE_LICENSE("GPL"); 80 MODULE_DESCRIPTION("842 Software Compression Algorithm"); 81 MODULE_ALIAS_CRYPTO("842"); 82 MODULE_ALIAS_CRYPTO("842-generic"); 83 MODULE_AUTHOR("Dan Streetman <ddstreet@ieee.org>"); 84