xref: /linux/lib/xz/xz_private.h (revision 55d0969c451159cff86949b38c39171cab962069)
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_IA64
28 #			define XZ_DEC_IA64
29 #		endif
30 #		ifdef CONFIG_XZ_DEC_ARM
31 #			define XZ_DEC_ARM
32 #		endif
33 #		ifdef CONFIG_XZ_DEC_ARMTHUMB
34 #			define XZ_DEC_ARMTHUMB
35 #		endif
36 #		ifdef CONFIG_XZ_DEC_SPARC
37 #			define XZ_DEC_SPARC
38 #		endif
39 #		ifdef CONFIG_XZ_DEC_ARM64
40 #			define XZ_DEC_ARM64
41 #		endif
42 #		ifdef CONFIG_XZ_DEC_RISCV
43 #			define XZ_DEC_RISCV
44 #		endif
45 #		ifdef CONFIG_XZ_DEC_MICROLZMA
46 #			define XZ_DEC_MICROLZMA
47 #		endif
48 #		define memeq(a, b, size) (memcmp(a, b, size) == 0)
49 #		define memzero(buf, size) memset(buf, 0, size)
50 #	endif
51 #	define get_le32(p) le32_to_cpup((const uint32_t *)(p))
52 #else
53 	/*
54 	 * For userspace builds, use a separate header to define the required
55 	 * macros and functions. This makes it easier to adapt the code into
56 	 * different environments and avoids clutter in the Linux kernel tree.
57 	 */
58 #	include "xz_config.h"
59 #endif
60 
61 /* If no specific decoding mode is requested, enable support for all modes. */
62 #if !defined(XZ_DEC_SINGLE) && !defined(XZ_DEC_PREALLOC) \
63 		&& !defined(XZ_DEC_DYNALLOC)
64 #	define XZ_DEC_SINGLE
65 #	define XZ_DEC_PREALLOC
66 #	define XZ_DEC_DYNALLOC
67 #endif
68 
69 /*
70  * The DEC_IS_foo(mode) macros are used in "if" statements. If only some
71  * of the supported modes are enabled, these macros will evaluate to true or
72  * false at compile time and thus allow the compiler to omit unneeded code.
73  */
74 #ifdef XZ_DEC_SINGLE
75 #	define DEC_IS_SINGLE(mode) ((mode) == XZ_SINGLE)
76 #else
77 #	define DEC_IS_SINGLE(mode) (false)
78 #endif
79 
80 #ifdef XZ_DEC_PREALLOC
81 #	define DEC_IS_PREALLOC(mode) ((mode) == XZ_PREALLOC)
82 #else
83 #	define DEC_IS_PREALLOC(mode) (false)
84 #endif
85 
86 #ifdef XZ_DEC_DYNALLOC
87 #	define DEC_IS_DYNALLOC(mode) ((mode) == XZ_DYNALLOC)
88 #else
89 #	define DEC_IS_DYNALLOC(mode) (false)
90 #endif
91 
92 #if !defined(XZ_DEC_SINGLE)
93 #	define DEC_IS_MULTI(mode) (true)
94 #elif defined(XZ_DEC_PREALLOC) || defined(XZ_DEC_DYNALLOC)
95 #	define DEC_IS_MULTI(mode) ((mode) != XZ_SINGLE)
96 #else
97 #	define DEC_IS_MULTI(mode) (false)
98 #endif
99 
100 /*
101  * If any of the BCJ filter decoders are wanted, define XZ_DEC_BCJ.
102  * XZ_DEC_BCJ is used to enable generic support for BCJ decoders.
103  */
104 #ifndef XZ_DEC_BCJ
105 #	if defined(XZ_DEC_X86) || defined(XZ_DEC_POWERPC) \
106 			|| defined(XZ_DEC_IA64) \
107 			|| defined(XZ_DEC_ARM) || defined(XZ_DEC_ARMTHUMB) \
108 			|| defined(XZ_DEC_SPARC) || defined(XZ_DEC_ARM64) \
109 			|| defined(XZ_DEC_RISCV)
110 #		define XZ_DEC_BCJ
111 #	endif
112 #endif
113 
114 /*
115  * Allocate memory for LZMA2 decoder. xz_dec_lzma2_reset() must be used
116  * before calling xz_dec_lzma2_run().
117  */
118 struct xz_dec_lzma2 *xz_dec_lzma2_create(enum xz_mode mode, uint32_t dict_max);
119 
120 /*
121  * Decode the LZMA2 properties (one byte) and reset the decoder. Return
122  * XZ_OK on success, XZ_MEMLIMIT_ERROR if the preallocated dictionary is not
123  * big enough, and XZ_OPTIONS_ERROR if props indicates something that this
124  * decoder doesn't support.
125  */
126 enum xz_ret xz_dec_lzma2_reset(struct xz_dec_lzma2 *s, uint8_t props);
127 
128 /* Decode raw LZMA2 stream from b->in to b->out. */
129 enum xz_ret xz_dec_lzma2_run(struct xz_dec_lzma2 *s, struct xz_buf *b);
130 
131 /* Free the memory allocated for the LZMA2 decoder. */
132 void xz_dec_lzma2_end(struct xz_dec_lzma2 *s);
133 
134 #ifdef XZ_DEC_BCJ
135 /*
136  * Allocate memory for BCJ decoders. xz_dec_bcj_reset() must be used before
137  * calling xz_dec_bcj_run().
138  */
139 struct xz_dec_bcj *xz_dec_bcj_create(bool single_call);
140 
141 /*
142  * Decode the Filter ID of a BCJ filter. This implementation doesn't
143  * support custom start offsets, so no decoding of Filter Properties
144  * is needed. Returns XZ_OK if the given Filter ID is supported.
145  * Otherwise XZ_OPTIONS_ERROR is returned.
146  */
147 enum xz_ret xz_dec_bcj_reset(struct xz_dec_bcj *s, uint8_t id);
148 
149 /*
150  * Decode raw BCJ + LZMA2 stream. This must be used only if there actually is
151  * a BCJ filter in the chain. If the chain has only LZMA2, xz_dec_lzma2_run()
152  * must be called directly.
153  */
154 enum xz_ret xz_dec_bcj_run(struct xz_dec_bcj *s, struct xz_dec_lzma2 *lzma2,
155 			   struct xz_buf *b);
156 
157 /* Free the memory allocated for the BCJ filters. */
158 #define xz_dec_bcj_end(s) kfree(s)
159 #endif
160 
161 #endif
162