xref: /linux/lib/xz/xz_private.h (revision 509d3f45847627f4c5cdce004c3ec79262b5239c)
1 /* SPDX-License-Identifier: 0BSD */
2 
3 /*
4  * Private includes and definitions
5  *
6  * Author: Lasse Collin <lasse.collin@tukaani.org>
7  */
8 
9 #ifndef XZ_PRIVATE_H
10 #define XZ_PRIVATE_H
11 
12 #ifdef __KERNEL__
13 #	include <linux/xz.h>
14 #	include <linux/kernel.h>
15 #	include <linux/unaligned.h>
16 	/* XZ_PREBOOT may be defined only via decompress_unxz.c. */
17 #	ifndef XZ_PREBOOT
18 #		include <linux/slab.h>
19 #		include <linux/vmalloc.h>
20 #		include <linux/string.h>
21 #		ifdef CONFIG_XZ_DEC_X86
22 #			define XZ_DEC_X86
23 #		endif
24 #		ifdef CONFIG_XZ_DEC_POWERPC
25 #			define XZ_DEC_POWERPC
26 #		endif
27 #		ifdef CONFIG_XZ_DEC_ARM
28 #			define XZ_DEC_ARM
29 #		endif
30 #		ifdef CONFIG_XZ_DEC_ARMTHUMB
31 #			define XZ_DEC_ARMTHUMB
32 #		endif
33 #		ifdef CONFIG_XZ_DEC_SPARC
34 #			define XZ_DEC_SPARC
35 #		endif
36 #		ifdef CONFIG_XZ_DEC_ARM64
37 #			define XZ_DEC_ARM64
38 #		endif
39 #		ifdef CONFIG_XZ_DEC_RISCV
40 #			define XZ_DEC_RISCV
41 #		endif
42 #		ifdef CONFIG_XZ_DEC_MICROLZMA
43 #			define XZ_DEC_MICROLZMA
44 #		endif
45 #		define memeq(a, b, size) (memcmp(a, b, size) == 0)
46 #		define memzero(buf, size) memset(buf, 0, size)
47 #	endif
48 #	define get_le32(p) le32_to_cpup((const uint32_t *)(p))
49 #else
50 	/*
51 	 * For userspace builds, use a separate header to define the required
52 	 * macros and functions. This makes it easier to adapt the code into
53 	 * different environments and avoids clutter in the Linux kernel tree.
54 	 */
55 #	include "xz_config.h"
56 #endif
57 
58 /* If no specific decoding mode is requested, enable support for all modes. */
59 #if !defined(XZ_DEC_SINGLE) && !defined(XZ_DEC_PREALLOC) \
60 		&& !defined(XZ_DEC_DYNALLOC)
61 #	define XZ_DEC_SINGLE
62 #	define XZ_DEC_PREALLOC
63 #	define XZ_DEC_DYNALLOC
64 #endif
65 
66 /*
67  * The DEC_IS_foo(mode) macros are used in "if" statements. If only some
68  * of the supported modes are enabled, these macros will evaluate to true or
69  * false at compile time and thus allow the compiler to omit unneeded code.
70  */
71 #ifdef XZ_DEC_SINGLE
72 #	define DEC_IS_SINGLE(mode) ((mode) == XZ_SINGLE)
73 #else
74 #	define DEC_IS_SINGLE(mode) (false)
75 #endif
76 
77 #ifdef XZ_DEC_PREALLOC
78 #	define DEC_IS_PREALLOC(mode) ((mode) == XZ_PREALLOC)
79 #else
80 #	define DEC_IS_PREALLOC(mode) (false)
81 #endif
82 
83 #ifdef XZ_DEC_DYNALLOC
84 #	define DEC_IS_DYNALLOC(mode) ((mode) == XZ_DYNALLOC)
85 #else
86 #	define DEC_IS_DYNALLOC(mode) (false)
87 #endif
88 
89 #if !defined(XZ_DEC_SINGLE)
90 #	define DEC_IS_MULTI(mode) (true)
91 #elif defined(XZ_DEC_PREALLOC) || defined(XZ_DEC_DYNALLOC)
92 #	define DEC_IS_MULTI(mode) ((mode) != XZ_SINGLE)
93 #else
94 #	define DEC_IS_MULTI(mode) (false)
95 #endif
96 
97 /*
98  * If any of the BCJ filter decoders are wanted, define XZ_DEC_BCJ.
99  * XZ_DEC_BCJ is used to enable generic support for BCJ decoders.
100  */
101 #ifndef XZ_DEC_BCJ
102 #	if defined(XZ_DEC_X86) || defined(XZ_DEC_POWERPC) \
103 			|| defined(XZ_DEC_ARM) || defined(XZ_DEC_ARMTHUMB) \
104 			|| defined(XZ_DEC_SPARC) || defined(XZ_DEC_ARM64) \
105 			|| defined(XZ_DEC_RISCV)
106 #		define XZ_DEC_BCJ
107 #	endif
108 #endif
109 
110 /*
111  * Allocate memory for LZMA2 decoder. xz_dec_lzma2_reset() must be used
112  * before calling xz_dec_lzma2_run().
113  */
114 struct xz_dec_lzma2 *xz_dec_lzma2_create(enum xz_mode mode, uint32_t dict_max);
115 
116 /*
117  * Decode the LZMA2 properties (one byte) and reset the decoder. Return
118  * XZ_OK on success, XZ_MEMLIMIT_ERROR if the preallocated dictionary is not
119  * big enough, and XZ_OPTIONS_ERROR if props indicates something that this
120  * decoder doesn't support.
121  */
122 enum xz_ret xz_dec_lzma2_reset(struct xz_dec_lzma2 *s, uint8_t props);
123 
124 /* Decode raw LZMA2 stream from b->in to b->out. */
125 enum xz_ret xz_dec_lzma2_run(struct xz_dec_lzma2 *s, struct xz_buf *b);
126 
127 /* Free the memory allocated for the LZMA2 decoder. */
128 void xz_dec_lzma2_end(struct xz_dec_lzma2 *s);
129 
130 #ifdef XZ_DEC_BCJ
131 /*
132  * Allocate memory for BCJ decoders. xz_dec_bcj_reset() must be used before
133  * calling xz_dec_bcj_run().
134  */
135 struct xz_dec_bcj *xz_dec_bcj_create(bool single_call);
136 
137 /*
138  * Decode the Filter ID of a BCJ filter. This implementation doesn't
139  * support custom start offsets, so no decoding of Filter Properties
140  * is needed. Returns XZ_OK if the given Filter ID is supported.
141  * Otherwise XZ_OPTIONS_ERROR is returned.
142  */
143 enum xz_ret xz_dec_bcj_reset(struct xz_dec_bcj *s, uint8_t id);
144 
145 /*
146  * Decode raw BCJ + LZMA2 stream. This must be used only if there actually is
147  * a BCJ filter in the chain. If the chain has only LZMA2, xz_dec_lzma2_run()
148  * must be called directly.
149  */
150 enum xz_ret xz_dec_bcj_run(struct xz_dec_bcj *s, struct xz_dec_lzma2 *lzma2,
151 			   struct xz_buf *b);
152 
153 /* Free the memory allocated for the BCJ filters. */
154 #define xz_dec_bcj_end(s) kfree(s)
155 #endif
156 
157 #endif
158