the-tree/crypto/842.c

0001 // SPDX-License-Identifier: GPL-2.0-or-later
0002 /*
0003  * Cryptographic API for the 842 software compression algorithm.
0004  *
0005  * Copyright (C) IBM Corporation, 2011-2015
0006  *
0007  * Original Authors: Robert Jennings <rcj@linux.vnet.ibm.com>
0008  *                   Seth Jennings <sjenning@linux.vnet.ibm.com>
0009  *
0010  * Rewrite: Dan Streetman <ddstreet@ieee.org>
0011  *
0012  * This is the software implementation of compression and decompression using
0013  * the 842 format.  This uses the software 842 library at lib/842/ which is
0014  * only a reference implementation, and is very, very slow as compared to other
0015  * software compressors.  You probably do not want to use this software
0016  * compression.  If you have access to the PowerPC 842 compression hardware, you
0017  * want to use the 842 hardware compression interface, which is at:
0018  * drivers/crypto/nx/nx-842-crypto.c
0019  */
0020
0021 #include <linux/init.h>
0022 #include <linux/module.h>
0023 #include <linux/crypto.h>
0024 #include <linux/sw842.h>
0025 #include <crypto/internal/scompress.h>
0026
0027 struct crypto842_ctx {
0028     void *wmem; /* working memory for compress */
0029 };
0030
0031 static void *crypto842_alloc_ctx(struct crypto_scomp *tfm)
0032 {
0033     void *ctx;
0034
0035     ctx = kmalloc(SW842_MEM_COMPRESS, GFP_KERNEL);
0036     if (!ctx)
0037         return ERR_PTR(-ENOMEM);
0038
0039     return ctx;
0040 }
0041
0042 static int crypto842_init(struct crypto_tfm *tfm)
0043 {
0044     struct crypto842_ctx *ctx = crypto_tfm_ctx(tfm);
0045
0046     ctx->wmem = crypto842_alloc_ctx(NULL);
0047     if (IS_ERR(ctx->wmem))
0048         return -ENOMEM;
0049
0050     return 0;
0051 }
0052
0053 static void crypto842_free_ctx(struct crypto_scomp *tfm, void *ctx)
0054 {
0055     kfree(ctx);
0056 }
0057
0058 static void crypto842_exit(struct crypto_tfm *tfm)
0059 {
0060     struct crypto842_ctx *ctx = crypto_tfm_ctx(tfm);
0061
0062     crypto842_free_ctx(NULL, ctx->wmem);
0063 }
0064
0065 static int crypto842_compress(struct crypto_tfm *tfm,
0066                   const u8 *src, unsigned int slen,
0067                   u8 *dst, unsigned int *dlen)
0068 {
0069     struct crypto842_ctx *ctx = crypto_tfm_ctx(tfm);
0070
0071     return sw842_compress(src, slen, dst, dlen, ctx->wmem);
0072 }
0073
0074 static int crypto842_scompress(struct crypto_scomp *tfm,
0075                    const u8 *src, unsigned int slen,
0076                    u8 *dst, unsigned int *dlen, void *ctx)
0077 {
0078     return sw842_compress(src, slen, dst, dlen, ctx);
0079 }
0080
0081 static int crypto842_decompress(struct crypto_tfm *tfm,
0082                 const u8 *src, unsigned int slen,
0083                 u8 *dst, unsigned int *dlen)
0084 {
0085     return sw842_decompress(src, slen, dst, dlen);
0086 }
0087
0088 static int crypto842_sdecompress(struct crypto_scomp *tfm,
0089                  const u8 *src, unsigned int slen,
0090                  u8 *dst, unsigned int *dlen, void *ctx)
0091 {
0092     return sw842_decompress(src, slen, dst, dlen);
0093 }
0094
0095 static struct crypto_alg alg = {
0096     .cra_name       = "842",
0097     .cra_driver_name    = "842-generic",
0098     .cra_priority       = 100,
0099     .cra_flags      = CRYPTO_ALG_TYPE_COMPRESS,
0100     .cra_ctxsize        = sizeof(struct crypto842_ctx),
0101     .cra_module     = THIS_MODULE,
0102     .cra_init       = crypto842_init,
0103     .cra_exit       = crypto842_exit,
0104     .cra_u          = { .compress = {
0105     .coa_compress       = crypto842_compress,
0106     .coa_decompress     = crypto842_decompress } }
0107 };
0108
0109 static struct scomp_alg scomp = {
0110     .alloc_ctx      = crypto842_alloc_ctx,
0111     .free_ctx       = crypto842_free_ctx,
0112     .compress       = crypto842_scompress,
0113     .decompress     = crypto842_sdecompress,
0114     .base           = {
0115         .cra_name   = "842",
0116         .cra_driver_name = "842-scomp",
0117         .cra_priority    = 100,
0118         .cra_module  = THIS_MODULE,
0119     }
0120 };
0121
0122 static int __init crypto842_mod_init(void)
0123 {
0124     int ret;
0125
0126     ret = crypto_register_alg(&alg);
0127     if (ret)
0128         return ret;
0129
0130     ret = crypto_register_scomp(&scomp);
0131     if (ret) {
0132         crypto_unregister_alg(&alg);
0133         return ret;
0134     }
0135
0136     return ret;
0137 }
0138 subsys_initcall(crypto842_mod_init);
0139
0140 static void __exit crypto842_mod_exit(void)
0141 {
0142     crypto_unregister_alg(&alg);
0143     crypto_unregister_scomp(&scomp);
0144 }
0145 module_exit(crypto842_mod_exit);
0146
0147 MODULE_LICENSE("GPL");
0148 MODULE_DESCRIPTION("842 Software Compression Algorithm");
0149 MODULE_ALIAS_CRYPTO("842");
0150 MODULE_ALIAS_CRYPTO("842-generic");
0151 MODULE_AUTHOR("Dan Streetman <ddstreet@ieee.org>");