/* * Cryptographic API for the 842 software compression algorithm. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * Copyright (C) IBM Corporation, 2011-2015 * * Original Authors: Robert Jennings <rcj@linux.vnet.ibm.com> * Seth Jennings <sjenning@linux.vnet.ibm.com> * * Rewrite: Dan Streetman <ddstreet@ieee.org> * * This is the software implementation of compression and decompression using * the 842 format. This uses the software 842 library at lib/842/ which is * only a reference implementation, and is very, very slow as compared to other * software compressors. You probably do not want to use this software * compression. If you have access to the PowerPC 842 compression hardware, you * want to use the 842 hardware compression interface, which is at: * drivers/crypto/nx/nx-842-crypto.c */ #include <linux/init.h> #include <linux/module.h> #include <linux/crypto.h> #include <linux/sw842.h> #include <crypto/internal/scompress.h> struct crypto842_ctx { void *wmem; /* working memory for compress */ }; static void *crypto842_alloc_ctx(struct crypto_scomp *tfm) { void *ctx; ctx = kmalloc(SW842_MEM_COMPRESS, GFP_KERNEL); if (!ctx) return ERR_PTR(-ENOMEM); return ctx; } static int crypto842_init(struct crypto_tfm *tfm) { struct crypto842_ctx *ctx = crypto_tfm_ctx(tfm); ctx->wmem = crypto842_alloc_ctx(NULL); if (IS_ERR(ctx->wmem)) return -ENOMEM; return 0; } static void crypto842_free_ctx(struct crypto_scomp *tfm, void *ctx) { kfree(ctx); } static void crypto842_exit(struct crypto_tfm *tfm) { struct crypto842_ctx *ctx = crypto_tfm_ctx(tfm); crypto842_free_ctx(NULL, ctx->wmem); } static int crypto842_compress(struct crypto_tfm *tfm, const u8 *src, unsigned int slen, u8 *dst, unsigned int *dlen) { struct crypto842_ctx *ctx = crypto_tfm_ctx(tfm); return sw842_compress(src, slen, dst, dlen, ctx->wmem); } static int crypto842_scompress(struct crypto_scomp *tfm, const u8 *src, unsigned int slen, u8 *dst, unsigned int *dlen, void *ctx) { return sw842_compress(src, slen, dst, dlen, ctx); } static int crypto842_decompress(struct crypto_tfm *tfm, const u8 *src, unsigned int slen, u8 *dst, unsigned int *dlen) { return sw842_decompress(src, slen, dst, dlen); } static int crypto842_sdecompress(struct crypto_scomp *tfm, const u8 *src, unsigned int slen, u8 *dst, unsigned int *dlen, void *ctx) { return sw842_decompress(src, slen, dst, dlen); } static struct crypto_alg alg = { .cra_name = "842", .cra_driver_name = "842-generic", .cra_priority = 100, .cra_flags = CRYPTO_ALG_TYPE_COMPRESS, .cra_ctxsize = sizeof(struct crypto842_ctx), .cra_module = THIS_MODULE, .cra_init = crypto842_init, .cra_exit = crypto842_exit, .cra_u = { .compress = { .coa_compress = crypto842_compress, .coa_decompress = crypto842_decompress } } }; static struct scomp_alg scomp = { .alloc_ctx = crypto842_alloc_ctx, .free_ctx = crypto842_free_ctx, .compress = crypto842_scompress, .decompress = crypto842_sdecompress, .base = { .cra_name = "842", .cra_driver_name = "842-scomp", .cra_priority = 100, .cra_module = THIS_MODULE, } }; static int __init crypto842_mod_init(void) { int ret; ret = crypto_register_alg(&alg); if (ret) return ret; ret = crypto_register_scomp(&scomp); if (ret) { crypto_unregister_alg(&alg); return ret; } return ret; } module_init(crypto842_mod_init); static void __exit crypto842_mod_exit(void) { crypto_unregister_alg(&alg); crypto_unregister_scomp(&scomp); } module_exit(crypto842_mod_exit); MODULE_LICENSE("GPL"); MODULE_DESCRIPTION("842 Software Compression Algorithm"); MODULE_ALIAS_CRYPTO("842"); MODULE_ALIAS_CRYPTO("842-generic"); MODULE_AUTHOR("Dan Streetman <ddstreet@ieee.org>");