| 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 | #include <crypto/internal/scompress.h> |
| 35 | |
| 36 | struct crypto842_ctx { |
| 37 | void *wmem; /* working memory for compress */ |
| 38 | }; |
| 39 | |
| 40 | static void *crypto842_alloc_ctx(struct crypto_scomp *tfm) |
| 41 | { |
| 42 | void *ctx; |
| 43 | |
| 44 | ctx = kmalloc(SW842_MEM_COMPRESS, GFP_KERNEL); |
| 45 | if (!ctx) |
| 46 | return ERR_PTR(-ENOMEM); |
| 47 | |
| 48 | return ctx; |
| 49 | } |
| 50 | |
| 51 | static int crypto842_init(struct crypto_tfm *tfm) |
| 52 | { |
| 53 | struct crypto842_ctx *ctx = crypto_tfm_ctx(tfm); |
| 54 | |
| 55 | ctx->wmem = crypto842_alloc_ctx(NULL); |
| 56 | if (IS_ERR(ctx->wmem)) |
| 57 | return -ENOMEM; |
| 58 | |
| 59 | return 0; |
| 60 | } |
| 61 | |
| 62 | static void crypto842_free_ctx(struct crypto_scomp *tfm, void *ctx) |
| 63 | { |
| 64 | kfree(ctx); |
| 65 | } |
| 66 | |
| 67 | static void crypto842_exit(struct crypto_tfm *tfm) |
| 68 | { |
| 69 | struct crypto842_ctx *ctx = crypto_tfm_ctx(tfm); |
| 70 | |
| 71 | crypto842_free_ctx(NULL, ctx->wmem); |
| 72 | } |
| 73 | |
| 74 | static int crypto842_compress(struct crypto_tfm *tfm, |
| 75 | const u8 *src, unsigned int slen, |
| 76 | u8 *dst, unsigned int *dlen) |
| 77 | { |
| 78 | struct crypto842_ctx *ctx = crypto_tfm_ctx(tfm); |
| 79 | |
| 80 | return sw842_compress(src, slen, dst, dlen, ctx->wmem); |
| 81 | } |
| 82 | |
| 83 | static int crypto842_scompress(struct crypto_scomp *tfm, |
| 84 | const u8 *src, unsigned int slen, |
| 85 | u8 *dst, unsigned int *dlen, void *ctx) |
| 86 | { |
| 87 | return sw842_compress(src, slen, dst, dlen, ctx); |
| 88 | } |
| 89 | |
| 90 | static int crypto842_decompress(struct crypto_tfm *tfm, |
| 91 | const u8 *src, unsigned int slen, |
| 92 | u8 *dst, unsigned int *dlen) |
| 93 | { |
| 94 | return sw842_decompress(src, slen, dst, dlen); |
| 95 | } |
| 96 | |
| 97 | static int crypto842_sdecompress(struct crypto_scomp *tfm, |
| 98 | const u8 *src, unsigned int slen, |
| 99 | u8 *dst, unsigned int *dlen, void *ctx) |
| 100 | { |
| 101 | return sw842_decompress(src, slen, dst, dlen); |
| 102 | } |
| 103 | |
| 104 | static struct crypto_alg alg = { |
| 105 | .cra_name = "842", |
| 106 | .cra_driver_name = "842-generic", |
| 107 | .cra_priority = 100, |
| 108 | .cra_flags = CRYPTO_ALG_TYPE_COMPRESS, |
| 109 | .cra_ctxsize = sizeof(struct crypto842_ctx), |
| 110 | .cra_module = THIS_MODULE, |
| 111 | .cra_init = crypto842_init, |
| 112 | .cra_exit = crypto842_exit, |
| 113 | .cra_u = { .compress = { |
| 114 | .coa_compress = crypto842_compress, |
| 115 | .coa_decompress = crypto842_decompress } } |
| 116 | }; |
| 117 | |
| 118 | static struct scomp_alg scomp = { |
| 119 | .alloc_ctx = crypto842_alloc_ctx, |
| 120 | .free_ctx = crypto842_free_ctx, |
| 121 | .compress = crypto842_scompress, |
| 122 | .decompress = crypto842_sdecompress, |
| 123 | .base = { |
| 124 | .cra_name = "842", |
| 125 | .cra_driver_name = "842-scomp", |
| 126 | .cra_priority = 100, |
| 127 | .cra_module = THIS_MODULE, |
| 128 | } |
| 129 | }; |
| 130 | |
| 131 | static int __init crypto842_mod_init(void) |
| 132 | { |
| 133 | int ret; |
| 134 | |
| 135 | ret = crypto_register_alg(&alg); |
| 136 | if (ret) |
| 137 | return ret; |
| 138 | |
| 139 | ret = crypto_register_scomp(&scomp); |
| 140 | if (ret) { |
| 141 | crypto_unregister_alg(&alg); |
| 142 | return ret; |
| 143 | } |
| 144 | |
| 145 | return ret; |
| 146 | } |
| 147 | module_init(crypto842_mod_init); |
| 148 | |
| 149 | static void __exit crypto842_mod_exit(void) |
| 150 | { |
| 151 | crypto_unregister_alg(&alg); |
| 152 | crypto_unregister_scomp(&scomp); |
| 153 | } |
| 154 | module_exit(crypto842_mod_exit); |
| 155 | |
| 156 | MODULE_LICENSE("GPL"); |
| 157 | MODULE_DESCRIPTION("842 Software Compression Algorithm"); |
| 158 | MODULE_ALIAS_CRYPTO("842"); |
| 159 | MODULE_ALIAS_CRYPTO("842-generic"); |
| 160 | MODULE_AUTHOR("Dan Streetman <ddstreet@ieee.org>"); |