1/*
2 * JFFS2 -- Journalling Flash File System, Version 2.
3 *
4 * Copyright © 2007 Nokia Corporation. All rights reserved.
5 * Copyright © 2004-2010 David Woodhouse <dwmw2@infradead.org>
6 *
7 * Created by Richard Purdie <rpurdie@openedhand.com>
8 *
9 * For licensing information, see the file 'LICENCE' in this directory.
10 *
11 */
12
13#include <linux/kernel.h>
14#include <linux/sched.h>
15#include <linux/vmalloc.h>
16#include <linux/init.h>
17#include <linux/lzo.h>
18#include "compr.h"
19
20static void *lzo_mem;
21static void *lzo_compress_buf;
22static DEFINE_MUTEX(deflate_mutex);	/* for lzo_mem and lzo_compress_buf */
23
24static void free_workspace(void)
25{
26	vfree(lzo_mem);
27	vfree(lzo_compress_buf);
28}
29
30static int __init alloc_workspace(void)
31{
32	lzo_mem = vmalloc(LZO1X_MEM_COMPRESS);
33	lzo_compress_buf = vmalloc(lzo1x_worst_compress(PAGE_SIZE));
34
35	if (!lzo_mem || !lzo_compress_buf) {
36		free_workspace();
37		return -ENOMEM;
38	}
39
40	return 0;
41}
42
43static int jffs2_lzo_compress(unsigned char *data_in, unsigned char *cpage_out,
44			      uint32_t *sourcelen, uint32_t *dstlen)
45{
46	size_t compress_size;
47	int ret;
48
49	mutex_lock(&deflate_mutex);
50	ret = lzo1x_1_compress(data_in, *sourcelen, lzo_compress_buf, &compress_size, lzo_mem);
51	if (ret != LZO_E_OK)
52		goto fail;
53
54	if (compress_size > *dstlen)
55		goto fail;
56
57	memcpy(cpage_out, lzo_compress_buf, compress_size);
58	mutex_unlock(&deflate_mutex);
59
60	*dstlen = compress_size;
61	return 0;
62
63 fail:
64	mutex_unlock(&deflate_mutex);
65	return -1;
66}
67
68static int jffs2_lzo_decompress(unsigned char *data_in, unsigned char *cpage_out,
69				 uint32_t srclen, uint32_t destlen)
70{
71	size_t dl = destlen;
72	int ret;
73
74	ret = lzo1x_decompress_safe(data_in, srclen, cpage_out, &dl);
75
76	if (ret != LZO_E_OK || dl != destlen)
77		return -1;
78
79	return 0;
80}
81
82static struct jffs2_compressor jffs2_lzo_comp = {
83	.priority = JFFS2_LZO_PRIORITY,
84	.name = "lzo",
85	.compr = JFFS2_COMPR_LZO,
86	.compress = &jffs2_lzo_compress,
87	.decompress = &jffs2_lzo_decompress,
88	.disabled = 0,
89};
90
91int __init jffs2_lzo_init(void)
92{
93	int ret;
94
95	ret = alloc_workspace();
96	if (ret < 0)
97		return ret;
98
99	ret = jffs2_register_compressor(&jffs2_lzo_comp);
100	if (ret)
101		free_workspace();
102
103	return ret;
104}
105
106void jffs2_lzo_exit(void)
107{
108	jffs2_unregister_compressor(&jffs2_lzo_comp);
109	free_workspace();
110}
111