root/lib/xz/xz_private.h

INCLUDED FROM

   1 /*
   2  * Private includes and definitions
   3  *
   4  * Author: Lasse Collin <lasse.collin@tukaani.org>
   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 #ifndef CRC32_POLY_LE
 106 #define CRC32_POLY_LE 0xedb88320
 107 #endif
 108 
 109 /*
 110  * Allocate memory for LZMA2 decoder. xz_dec_lzma2_reset() must be used
 111  * before calling xz_dec_lzma2_run().
 112  */
 113 XZ_EXTERN struct xz_dec_lzma2 *xz_dec_lzma2_create(enum xz_mode mode,
 114                                                    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 XZ_EXTERN enum xz_ret xz_dec_lzma2_reset(struct xz_dec_lzma2 *s,
 123                                          uint8_t props);
 124 
 125 /* Decode raw LZMA2 stream from b->in to b->out. */
 126 XZ_EXTERN enum xz_ret xz_dec_lzma2_run(struct xz_dec_lzma2 *s,
 127                                        struct xz_buf *b);
 128 
 129 /* Free the memory allocated for the LZMA2 decoder. */
 130 XZ_EXTERN void xz_dec_lzma2_end(struct xz_dec_lzma2 *s);
 131 
 132 #ifdef XZ_DEC_BCJ
 133 /*
 134  * Allocate memory for BCJ decoders. xz_dec_bcj_reset() must be used before
 135  * calling xz_dec_bcj_run().
 136  */
 137 XZ_EXTERN struct xz_dec_bcj *xz_dec_bcj_create(bool single_call);
 138 
 139 /*
 140  * Decode the Filter ID of a BCJ filter. This implementation doesn't
 141  * support custom start offsets, so no decoding of Filter Properties
 142  * is needed. Returns XZ_OK if the given Filter ID is supported.
 143  * Otherwise XZ_OPTIONS_ERROR is returned.
 144  */
 145 XZ_EXTERN enum xz_ret xz_dec_bcj_reset(struct xz_dec_bcj *s, uint8_t id);
 146 
 147 /*
 148  * Decode raw BCJ + LZMA2 stream. This must be used only if there actually is
 149  * a BCJ filter in the chain. If the chain has only LZMA2, xz_dec_lzma2_run()
 150  * must be called directly.
 151  */
 152 XZ_EXTERN enum xz_ret xz_dec_bcj_run(struct xz_dec_bcj *s,
 153                                      struct xz_dec_lzma2 *lzma2,
 154                                      struct xz_buf *b);
 155 
 156 /* Free the memory allocated for the BCJ filters. */
 157 #define xz_dec_bcj_end(s) kfree(s)
 158 #endif
 159 
 160 #endif