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 */
114struct 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 */
122enum 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. */
125enum 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. */
128void 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 */
135struct 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 */
143enum 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 */
150enum 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

source code of linux/lib/xz/xz_private.h