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xz_private.h
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1 /*
2  * Private includes and definitions
3  *
4  * Author: Lasse Collin <[email protected]>
5  *
6  * This file has been put into the public domain.
7  * You can do whatever you want with this file.
8  */
9 
10 #ifndef XZ_PRIVATE_H
11 #define XZ_PRIVATE_H
12 
13 #ifdef __KERNEL__
14 # include <linux/xz.h>
15 # include <linux/kernel.h>
16 # include <asm/unaligned.h>
17  /* XZ_PREBOOT may be defined only via decompress_unxz.c. */
18 # ifndef XZ_PREBOOT
19 # include <linux/slab.h>
20 # include <linux/vmalloc.h>
21 # include <linux/string.h>
22 # ifdef CONFIG_XZ_DEC_X86
23 # define XZ_DEC_X86
24 # endif
25 # ifdef CONFIG_XZ_DEC_POWERPC
26 # define XZ_DEC_POWERPC
27 # endif
28 # ifdef CONFIG_XZ_DEC_IA64
29 # define XZ_DEC_IA64
30 # endif
31 # ifdef CONFIG_XZ_DEC_ARM
32 # define XZ_DEC_ARM
33 # endif
34 # ifdef CONFIG_XZ_DEC_ARMTHUMB
35 # define XZ_DEC_ARMTHUMB
36 # endif
37 # ifdef CONFIG_XZ_DEC_SPARC
38 # define XZ_DEC_SPARC
39 # endif
40 # define memeq(a, b, size) (memcmp(a, b, size) == 0)
41 # define memzero(buf, size) memset(buf, 0, size)
42 # endif
43 # define get_le32(p) le32_to_cpup((const uint32_t *)(p))
44 #else
45  /*
46  * For userspace builds, use a separate header to define the required
47  * macros and functions. This makes it easier to adapt the code into
48  * different environments and avoids clutter in the Linux kernel tree.
49  */
50 # include "xz_config.h"
51 #endif
52 
53 /* If no specific decoding mode is requested, enable support for all modes. */
54 #if !defined(XZ_DEC_SINGLE) && !defined(XZ_DEC_PREALLOC) \
55  && !defined(XZ_DEC_DYNALLOC)
56 # define XZ_DEC_SINGLE
57 # define XZ_DEC_PREALLOC
58 # define XZ_DEC_DYNALLOC
59 #endif
60 
61 /*
62  * The DEC_IS_foo(mode) macros are used in "if" statements. If only some
63  * of the supported modes are enabled, these macros will evaluate to true or
64  * false at compile time and thus allow the compiler to omit unneeded code.
65  */
66 #ifdef XZ_DEC_SINGLE
67 # define DEC_IS_SINGLE(mode) ((mode) == XZ_SINGLE)
68 #else
69 # define DEC_IS_SINGLE(mode) (false)
70 #endif
71 
72 #ifdef XZ_DEC_PREALLOC
73 # define DEC_IS_PREALLOC(mode) ((mode) == XZ_PREALLOC)
74 #else
75 # define DEC_IS_PREALLOC(mode) (false)
76 #endif
77 
78 #ifdef XZ_DEC_DYNALLOC
79 # define DEC_IS_DYNALLOC(mode) ((mode) == XZ_DYNALLOC)
80 #else
81 # define DEC_IS_DYNALLOC(mode) (false)
82 #endif
83 
84 #if !defined(XZ_DEC_SINGLE)
85 # define DEC_IS_MULTI(mode) (true)
86 #elif defined(XZ_DEC_PREALLOC) || defined(XZ_DEC_DYNALLOC)
87 # define DEC_IS_MULTI(mode) ((mode) != XZ_SINGLE)
88 #else
89 # define DEC_IS_MULTI(mode) (false)
90 #endif
91 
92 /*
93  * If any of the BCJ filter decoders are wanted, define XZ_DEC_BCJ.
94  * XZ_DEC_BCJ is used to enable generic support for BCJ decoders.
95  */
96 #ifndef XZ_DEC_BCJ
97 # if defined(XZ_DEC_X86) || defined(XZ_DEC_POWERPC) \
98  || defined(XZ_DEC_IA64) || defined(XZ_DEC_ARM) \
99  || defined(XZ_DEC_ARM) || defined(XZ_DEC_ARMTHUMB) \
100  || defined(XZ_DEC_SPARC)
101 # define XZ_DEC_BCJ
102 # endif
103 #endif
104 
105 /*
106  * Allocate memory for LZMA2 decoder. xz_dec_lzma2_reset() must be used
107  * before calling xz_dec_lzma2_run().
108  */
110  uint32_t dict_max);
111 
112 /*
113  * Decode the LZMA2 properties (one byte) and reset the decoder. Return
114  * XZ_OK on success, XZ_MEMLIMIT_ERROR if the preallocated dictionary is not
115  * big enough, and XZ_OPTIONS_ERROR if props indicates something that this
116  * decoder doesn't support.
117  */
119  uint8_t props);
120 
121 /* Decode raw LZMA2 stream from b->in to b->out. */
123  struct xz_buf *b);
124 
125 /* Free the memory allocated for the LZMA2 decoder. */
127 
128 #ifdef XZ_DEC_BCJ
129 /*
130  * Allocate memory for BCJ decoders. xz_dec_bcj_reset() must be used before
131  * calling xz_dec_bcj_run().
132  */
133 XZ_EXTERN struct xz_dec_bcj *xz_dec_bcj_create(bool single_call);
134 
135 /*
136  * Decode the Filter ID of a BCJ filter. This implementation doesn't
137  * support custom start offsets, so no decoding of Filter Properties
138  * is needed. Returns XZ_OK if the given Filter ID is supported.
139  * Otherwise XZ_OPTIONS_ERROR is returned.
140  */
141 XZ_EXTERN enum xz_ret xz_dec_bcj_reset(struct xz_dec_bcj *s, uint8_t id);
142 
143 /*
144  * Decode raw BCJ + LZMA2 stream. This must be used only if there actually is
145  * a BCJ filter in the chain. If the chain has only LZMA2, xz_dec_lzma2_run()
146  * must be called directly.
147  */
148 XZ_EXTERN enum xz_ret xz_dec_bcj_run(struct xz_dec_bcj *s,
149  struct xz_dec_lzma2 *lzma2,
150  struct xz_buf *b);
151 
152 /* Free the memory allocated for the BCJ filters. */
153 #define xz_dec_bcj_end(s) kfree(s)
154 #endif
155 
156 #endif