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c799aca3 RP |
1 | /* |
2 | * JFFS2 -- Journalling Flash File System, Version 2. | |
3 | * | |
4 | * Copyright © 2007 Nokia Corporation. All rights reserved. | |
5 | * | |
6 | * Created by Richard Purdie <rpurdie@openedhand.com> | |
7 | * | |
8 | * For licensing information, see the file 'LICENCE' in this directory. | |
9 | * | |
10 | */ | |
11 | ||
12 | #include <linux/kernel.h> | |
13 | #include <linux/sched.h> | |
14 | #include <linux/slab.h> | |
15 | #include <linux/vmalloc.h> | |
16 | #include <linux/init.h> | |
17 | #include <linux/lzo.h> | |
18 | #include "compr.h" | |
19 | ||
20 | static void *lzo_mem; | |
21 | static void *lzo_compress_buf; | |
22 | static DEFINE_MUTEX(deflate_mutex); | |
23 | ||
24 | static void free_workspace(void) | |
25 | { | |
26 | vfree(lzo_mem); | |
27 | vfree(lzo_compress_buf); | |
28 | } | |
29 | ||
30 | static 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 | printk(KERN_WARNING "Failed to allocate lzo deflate workspace\n"); | |
37 | free_workspace(); | |
38 | return -ENOMEM; | |
39 | } | |
40 | ||
41 | return 0; | |
42 | } | |
43 | ||
44 | static int jffs2_lzo_compress(unsigned char *data_in, unsigned char *cpage_out, | |
45 | uint32_t *sourcelen, uint32_t *dstlen, void *model) | |
46 | { | |
47 | size_t compress_size; | |
48 | int ret; | |
49 | ||
50 | mutex_lock(&deflate_mutex); | |
51 | ret = lzo1x_1_compress(data_in, *sourcelen, lzo_compress_buf, &compress_size, lzo_mem); | |
52 | mutex_unlock(&deflate_mutex); | |
53 | ||
54 | if (ret != LZO_E_OK) | |
55 | return -1; | |
56 | ||
57 | if (compress_size > *dstlen) | |
58 | return -1; | |
59 | ||
60 | memcpy(cpage_out, lzo_compress_buf, compress_size); | |
61 | *dstlen = compress_size; | |
62 | ||
63 | return 0; | |
64 | } | |
65 | ||
66 | static int jffs2_lzo_decompress(unsigned char *data_in, unsigned char *cpage_out, | |
67 | uint32_t srclen, uint32_t destlen, void *model) | |
68 | { | |
69 | size_t dl = destlen; | |
70 | int ret; | |
71 | ||
72 | ret = lzo1x_decompress_safe(data_in, srclen, cpage_out, &dl); | |
73 | ||
74 | if (ret != LZO_E_OK || dl != destlen) | |
75 | return -1; | |
76 | ||
77 | return 0; | |
78 | } | |
79 | ||
80 | static struct jffs2_compressor jffs2_lzo_comp = { | |
81 | .priority = JFFS2_LZO_PRIORITY, | |
82 | .name = "lzo", | |
83 | .compr = JFFS2_COMPR_LZO, | |
84 | .compress = &jffs2_lzo_compress, | |
85 | .decompress = &jffs2_lzo_decompress, | |
86 | .disabled = 0, | |
87 | }; | |
88 | ||
89 | int __init jffs2_lzo_init(void) | |
90 | { | |
91 | int ret; | |
92 | ||
93 | ret = alloc_workspace(); | |
94 | if (ret < 0) | |
95 | return ret; | |
96 | ||
97 | ret = jffs2_register_compressor(&jffs2_lzo_comp); | |
98 | if (ret) | |
99 | free_workspace(); | |
100 | ||
101 | return ret; | |
102 | } | |
103 | ||
104 | void jffs2_lzo_exit(void) | |
105 | { | |
106 | jffs2_unregister_compressor(&jffs2_lzo_comp); | |
107 | free_workspace(); | |
108 | } |