| 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>"); |