842.c

 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 <crypto/internal/scompress.h>
22#include <linux/init.h>
23#include <linux/module.h>
24#include <linux/sw842.h>
25
26static void *crypto842_alloc_ctx(void)
27{
28	void *ctx;
29
30	ctx = kmalloc(SW842_MEM_COMPRESS, GFP_KERNEL);
31	if (!ctx)
32		return ERR_PTR(-ENOMEM);
33
34	return ctx;
35}
36
37static void crypto842_free_ctx(void *ctx)
38{
39	kfree(ctx);
40}
41
42static int crypto842_scompress(struct crypto_scomp *tfm,
43			       const u8 *src, unsigned int slen,
44			       u8 *dst, unsigned int *dlen, void *ctx)
45{
46	return sw842_compress(src, slen, dst, dlen, ctx);
47}
48
49static int crypto842_sdecompress(struct crypto_scomp *tfm,
50				 const u8 *src, unsigned int slen,
51				 u8 *dst, unsigned int *dlen, void *ctx)
52{
53	return sw842_decompress(src, slen, dst, dlen);
54}
55
56static struct scomp_alg scomp = {
57	.streams		= {
58		.alloc_ctx	= crypto842_alloc_ctx,
59		.free_ctx	= crypto842_free_ctx,
60	},
61	.compress		= crypto842_scompress,
62	.decompress		= crypto842_sdecompress,
63	.base			= {
64		.cra_name	= "842",
65		.cra_driver_name = "842-scomp",
66		.cra_priority	 = 100,
67		.cra_module	 = THIS_MODULE,
68	}
69};
70
71static int __init crypto842_mod_init(void)
72{
73	return crypto_register_scomp(&scomp);
74}
75module_init(crypto842_mod_init);
76
77static void __exit crypto842_mod_exit(void)
78{
79	crypto_unregister_scomp(&scomp);
80}
81module_exit(crypto842_mod_exit);
82
83MODULE_LICENSE("GPL");
84MODULE_DESCRIPTION("842 Software Compression Algorithm");
85MODULE_ALIAS_CRYPTO("842");
86MODULE_ALIAS_CRYPTO("842-generic");
87MODULE_AUTHOR("Dan Streetman <ddstreet@ieee.org>");