1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * Cryptographic API for the 842 software compression algorithm.
  4 *
  5 * Copyright (C) IBM Corporation, 2011-2015
  6 *
  7 * Original Authors: Robert Jennings <rcj@linux.vnet.ibm.com>
  8 *                   Seth Jennings <sjenning@linux.vnet.ibm.com>
  9 *
 10 * Rewrite: Dan Streetman <ddstreet@ieee.org>
 11 *
 12 * This is the software implementation of compression and decompression using
 13 * the 842 format.  This uses the software 842 library at lib/842/ which is
 14 * only a reference implementation, and is very, very slow as compared to other
 15 * software compressors.  You probably do not want to use this software
 16 * compression.  If you have access to the PowerPC 842 compression hardware, you
 17 * want to use the 842 hardware compression interface, which is at:
 18 * drivers/crypto/nx/nx-842-crypto.c
 19 */
 20
 21#include <linux/init.h>
 22#include <linux/module.h>
 23#include <linux/crypto.h>
 24#include <linux/sw842.h>
 25#include <crypto/internal/scompress.h>
 26
 27struct crypto842_ctx {
 28	void *wmem;	/* working memory for compress */
 29};
 30
 31static void *crypto842_alloc_ctx(struct crypto_scomp *tfm)
 32{
 33	void *ctx;
 34
 35	ctx = kmalloc(SW842_MEM_COMPRESS, GFP_KERNEL);
 36	if (!ctx)
 37		return ERR_PTR(-ENOMEM);
 38
 39	return ctx;
 40}
 41
 42static int crypto842_init(struct crypto_tfm *tfm)
 43{
 44	struct crypto842_ctx *ctx = crypto_tfm_ctx(tfm);
 45
 46	ctx->wmem = crypto842_alloc_ctx(NULL);
 47	if (IS_ERR(ctx->wmem))
 48		return -ENOMEM;
 49
 50	return 0;
 51}
 52
 53static void crypto842_free_ctx(struct crypto_scomp *tfm, void *ctx)
 54{
 55	kfree(ctx);
 56}
 57
 58static void crypto842_exit(struct crypto_tfm *tfm)
 59{
 60	struct crypto842_ctx *ctx = crypto_tfm_ctx(tfm);
 61
 62	crypto842_free_ctx(NULL, ctx->wmem);
 63}
 64
 65static int crypto842_compress(struct crypto_tfm *tfm,
 66			      const u8 *src, unsigned int slen,
 67			      u8 *dst, unsigned int *dlen)
 68{
 69	struct crypto842_ctx *ctx = crypto_tfm_ctx(tfm);
 70
 71	return sw842_compress(src, slen, dst, dlen, ctx->wmem);
 72}
 73
 74static int crypto842_scompress(struct crypto_scomp *tfm,
 75			       const u8 *src, unsigned int slen,
 76			       u8 *dst, unsigned int *dlen, void *ctx)
 77{
 78	return sw842_compress(src, slen, dst, dlen, ctx);
 79}
 80
 81static int crypto842_decompress(struct crypto_tfm *tfm,
 82				const u8 *src, unsigned int slen,
 83				u8 *dst, unsigned int *dlen)
 84{
 85	return sw842_decompress(src, slen, dst, dlen);
 86}
 87
 88static int crypto842_sdecompress(struct crypto_scomp *tfm,
 89				 const u8 *src, unsigned int slen,
 90				 u8 *dst, unsigned int *dlen, void *ctx)
 91{
 92	return sw842_decompress(src, slen, dst, dlen);
 93}
 94
 95static struct crypto_alg alg = {
 96	.cra_name		= "842",
 97	.cra_driver_name	= "842-generic",
 98	.cra_priority		= 100,
 99	.cra_flags		= CRYPTO_ALG_TYPE_COMPRESS,
100	.cra_ctxsize		= sizeof(struct crypto842_ctx),
101	.cra_module		= THIS_MODULE,
102	.cra_init		= crypto842_init,
103	.cra_exit		= crypto842_exit,
104	.cra_u			= { .compress = {
105	.coa_compress		= crypto842_compress,
106	.coa_decompress		= crypto842_decompress } }
107};
108
109static struct scomp_alg scomp = {
110	.alloc_ctx		= crypto842_alloc_ctx,
111	.free_ctx		= crypto842_free_ctx,
112	.compress		= crypto842_scompress,
113	.decompress		= crypto842_sdecompress,
114	.base			= {
115		.cra_name	= "842",
116		.cra_driver_name = "842-scomp",
117		.cra_priority	 = 100,
118		.cra_module	 = THIS_MODULE,
119	}
120};
121
122static int __init crypto842_mod_init(void)
123{
124	int ret;
125
126	ret = crypto_register_alg(&alg);
127	if (ret)
128		return ret;
129
130	ret = crypto_register_scomp(&scomp);
131	if (ret) {
132		crypto_unregister_alg(&alg);
133		return ret;
134	}
135
136	return ret;
137}
138subsys_initcall(crypto842_mod_init);
139
140static void __exit crypto842_mod_exit(void)
141{
142	crypto_unregister_alg(&alg);
143	crypto_unregister_scomp(&scomp);
144}
145module_exit(crypto842_mod_exit);
146
147MODULE_LICENSE("GPL");
148MODULE_DESCRIPTION("842 Software Compression Algorithm");
149MODULE_ALIAS_CRYPTO("842");
150MODULE_ALIAS_CRYPTO("842-generic");
151MODULE_AUTHOR("Dan Streetman <ddstreet@ieee.org>");