xref: /linux/fs/jffs2/compr.h (revision 60e13231561b3a4c5269bfa1ef6c0569ad6f28ec)
1 /*
2  * JFFS2 -- Journalling Flash File System, Version 2.
3  *
4  * Copyright © 2004   Ferenc Havasi <havasi@inf.u-szeged.hu>,
5  *		      University of Szeged, Hungary
6  * Copyright © 2004-2010 David Woodhouse <dwmw2@infradead.org>
7  *
8  * For licensing information, see the file 'LICENCE' in this directory.
9  *
10  */
11 
12 #ifndef __JFFS2_COMPR_H__
13 #define __JFFS2_COMPR_H__
14 
15 #include <linux/kernel.h>
16 #include <linux/vmalloc.h>
17 #include <linux/list.h>
18 #include <linux/types.h>
19 #include <linux/string.h>
20 #include <linux/slab.h>
21 #include <linux/errno.h>
22 #include <linux/fs.h>
23 #include <linux/jffs2.h>
24 #include "jffs2_fs_i.h"
25 #include "jffs2_fs_sb.h"
26 #include "nodelist.h"
27 
28 #define JFFS2_RUBINMIPS_PRIORITY 10
29 #define JFFS2_DYNRUBIN_PRIORITY  20
30 #define JFFS2_LZARI_PRIORITY     30
31 #define JFFS2_RTIME_PRIORITY     50
32 #define JFFS2_ZLIB_PRIORITY      60
33 #define JFFS2_LZO_PRIORITY       80
34 
35 
36 #define JFFS2_RUBINMIPS_DISABLED /* RUBINs will be used only */
37 #define JFFS2_DYNRUBIN_DISABLED  /*	   for decompression */
38 
39 #define JFFS2_COMPR_MODE_NONE       0
40 #define JFFS2_COMPR_MODE_PRIORITY   1
41 #define JFFS2_COMPR_MODE_SIZE       2
42 #define JFFS2_COMPR_MODE_FAVOURLZO  3
43 
44 #define FAVOUR_LZO_PERCENT 80
45 
46 struct jffs2_compressor {
47 	struct list_head list;
48 	int priority;			/* used by prirority comr. mode */
49 	char *name;
50 	char compr;			/* JFFS2_COMPR_XXX */
51 	int (*compress)(unsigned char *data_in, unsigned char *cpage_out,
52 			uint32_t *srclen, uint32_t *destlen);
53 	int (*decompress)(unsigned char *cdata_in, unsigned char *data_out,
54 			  uint32_t cdatalen, uint32_t datalen);
55 	int usecount;
56 	int disabled;		/* if set the compressor won't compress */
57 	unsigned char *compr_buf;	/* used by size compr. mode */
58 	uint32_t compr_buf_size;	/* used by size compr. mode */
59 	uint32_t stat_compr_orig_size;
60 	uint32_t stat_compr_new_size;
61 	uint32_t stat_compr_blocks;
62 	uint32_t stat_decompr_blocks;
63 };
64 
65 int jffs2_register_compressor(struct jffs2_compressor *comp);
66 int jffs2_unregister_compressor(struct jffs2_compressor *comp);
67 
68 int jffs2_compressors_init(void);
69 int jffs2_compressors_exit(void);
70 
71 uint16_t jffs2_compress(struct jffs2_sb_info *c, struct jffs2_inode_info *f,
72 			unsigned char *data_in, unsigned char **cpage_out,
73 			uint32_t *datalen, uint32_t *cdatalen);
74 
75 int jffs2_decompress(struct jffs2_sb_info *c, struct jffs2_inode_info *f,
76 		     uint16_t comprtype, unsigned char *cdata_in,
77 		     unsigned char *data_out, uint32_t cdatalen, uint32_t datalen);
78 
79 void jffs2_free_comprbuf(unsigned char *comprbuf, unsigned char *orig);
80 
81 /* Compressor modules */
82 /* These functions will be called by jffs2_compressors_init/exit */
83 
84 #ifdef CONFIG_JFFS2_RUBIN
85 int jffs2_rubinmips_init(void);
86 void jffs2_rubinmips_exit(void);
87 int jffs2_dynrubin_init(void);
88 void jffs2_dynrubin_exit(void);
89 #endif
90 #ifdef CONFIG_JFFS2_RTIME
91 int jffs2_rtime_init(void);
92 void jffs2_rtime_exit(void);
93 #endif
94 #ifdef CONFIG_JFFS2_ZLIB
95 int jffs2_zlib_init(void);
96 void jffs2_zlib_exit(void);
97 #endif
98 #ifdef CONFIG_JFFS2_LZO
99 int jffs2_lzo_init(void);
100 void jffs2_lzo_exit(void);
101 #endif
102 
103 #endif /* __JFFS2_COMPR_H__ */
104