lib/lz4/lz4defs.h

   1 #ifndef __LZ4DEFS_H__
   2 #define __LZ4DEFS_H__
   3
   4 /*
   5  * lz4defs.h -- common and architecture specific defines for the kernel usage
   6
   7  * LZ4 - Fast LZ compression algorithm
   8  * Copyright (C) 2011-2016, Yann Collet.
   9  * BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions are
  12  * met:
  13  *      * Redistributions of source code must retain the above copyright
  14  *        notice, this list of conditions and the following disclaimer.
  15  *      * Redistributions in binary form must reproduce the above
  16  * copyright notice, this list of conditions and the following disclaimer
  17  * in the documentation and/or other materials provided with the
  18  * distribution.
  19  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  20  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  21  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  22  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  23  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  24  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  25  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  26  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  27  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  28  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  29  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  30  * You can contact the author at :
  31  *      - LZ4 homepage : http://www.lz4.org
  32  *      - LZ4 source repository : https://github.com/lz4/lz4
  33  *
  34  *      Changed for kernel usage by:
  35  *      Sven Schmidt <4sschmid@informatik.uni-hamburg.de>
  36  */
  37
  38 #include <asm/unaligned.h>
  39 #include <linux/string.h>        /* memset, memcpy */
  40
  41 #define FORCE_INLINE __always_inline
  42
  43 /*-************************************
  44  *      Basic Types
  45  **************************************/
  46 #include <linux/types.h>
  47
  48 typedef uint8_t BYTE;
  49 typedef uint16_t U16;
  50 typedef uint32_t U32;
  51 typedef int32_t S32;
  52 typedef uint64_t U64;
  53 typedef uintptr_t uptrval;
  54
  55 /*-************************************
  56  *      Architecture specifics
  57  **************************************/
  58 #if defined(CONFIG_64BIT)
  59 #define LZ4_ARCH64 1
  60 #else
  61 #define LZ4_ARCH64 0
  62 #endif
  63
  64 #if defined(__LITTLE_ENDIAN)
  65 #define LZ4_LITTLE_ENDIAN 1
  66 #else
  67 #define LZ4_LITTLE_ENDIAN 0
  68 #endif
  69
  70 /*-************************************
  71  *      Constants
  72  **************************************/
  73 #define MINMATCH 4
  74
  75 #define WILDCOPYLENGTH 8
  76 #define LASTLITERALS 5
  77 #define MFLIMIT (WILDCOPYLENGTH + MINMATCH)
  78
  79 /* Increase this value ==> compression run slower on incompressible data */
  80 #define LZ4_SKIPTRIGGER 6
  81
  82 #define HASH_UNIT sizeof(size_t)
  83
  84 #define KB (1 << 10)
  85 #define MB (1 << 20)
  86 #define GB (1U << 30)
  87
  88 #define MAXD_LOG 16
  89 #define MAX_DISTANCE ((1 << MAXD_LOG) - 1)
  90 #define STEPSIZE sizeof(size_t)
  91
  92 #define ML_BITS 4
  93 #define ML_MASK ((1U << ML_BITS) - 1)
  94 #define RUN_BITS (8 - ML_BITS)
  95 #define RUN_MASK ((1U << RUN_BITS) - 1)
  96
  97 /*-************************************
  98  *      Reading and writing into memory
  99  **************************************/
 100 static FORCE_INLINE U16 LZ4_read16(const void *ptr)
 101 {
 102         return get_unaligned((const U16 *)ptr);
 103 }
 104
 105 static FORCE_INLINE U32 LZ4_read32(const void *ptr)
 106 {
 107         return get_unaligned((const U32 *)ptr);
 108 }
 109
 110 static FORCE_INLINE size_t LZ4_read_ARCH(const void *ptr)
 111 {
 112         return get_unaligned((const size_t *)ptr);
 113 }
 114
 115 static FORCE_INLINE void LZ4_write16(void *memPtr, U16 value)
 116 {
 117         put_unaligned(value, (U16 *)memPtr);
 118 }
 119
 120 static FORCE_INLINE void LZ4_write32(void *memPtr, U32 value)
 121 {
 122         put_unaligned(value, (U32 *)memPtr);
 123 }
 124
 125 static FORCE_INLINE U16 LZ4_readLE16(const void *memPtr)
 126 {
 127         return get_unaligned_le16(memPtr);
 128 }
 129
 130 static FORCE_INLINE void LZ4_writeLE16(void *memPtr, U16 value)
 131 {
 132         return put_unaligned_le16(value, memPtr);
 133 }
 134
 135 static FORCE_INLINE void LZ4_copy8(void *dst, const void *src)
 136 {
 137 #if LZ4_ARCH64
 138         U64 a = get_unaligned((const U64 *)src);
 139
 140         put_unaligned(a, (U64 *)dst);
 141 #else
 142         U32 a = get_unaligned((const U32 *)src);
 143         U32 b = get_unaligned((const U32 *)src + 1);
 144
 145         put_unaligned(a, (U32 *)dst);
 146         put_unaligned(b, (U32 *)dst + 1);
 147 #endif
 148 }
 149
 150 /*
 151  * customized variant of memcpy,
 152  * which can overwrite up to 7 bytes beyond dstEnd
 153  */
 154 static FORCE_INLINE void LZ4_wildCopy(void *dstPtr,
 155         const void *srcPtr, void *dstEnd)
 156 {
 157         BYTE *d = (BYTE *)dstPtr;
 158         const BYTE *s = (const BYTE *)srcPtr;
 159         BYTE *const e = (BYTE *)dstEnd;
 160
 161         do {
 162                 LZ4_copy8(d, s);
 163                 d += 8;
 164                 s += 8;
 165         } while (d < e);
 166 }
 167
 168 static FORCE_INLINE unsigned int LZ4_NbCommonBytes(register size_t val)
 169 {
 170 #if LZ4_LITTLE_ENDIAN
 171         return __ffs(val) >> 3;
 172 #else
 173         return (BITS_PER_LONG - 1 - __fls(val)) >> 3;
 174 #endif
 175 }
 176
 177 static FORCE_INLINE unsigned int LZ4_count(
 178         const BYTE *pIn,
 179         const BYTE *pMatch,
 180         const BYTE *pInLimit)
 181 {
 182         const BYTE *const pStart = pIn;
 183
 184         while (likely(pIn < pInLimit - (STEPSIZE - 1))) {
 185                 size_t const diff = LZ4_read_ARCH(pMatch) ^ LZ4_read_ARCH(pIn);
 186
 187                 if (!diff) {
 188                         pIn += STEPSIZE;
 189                         pMatch += STEPSIZE;
 190                         continue;
 191                 }
 192
 193                 pIn += LZ4_NbCommonBytes(diff);
 194
 195                 return (unsigned int)(pIn - pStart);
 196         }
 197
 198 #if LZ4_ARCH64
 199         if ((pIn < (pInLimit - 3))
 200                 && (LZ4_read32(pMatch) == LZ4_read32(pIn))) {
 201                 pIn += 4;
 202                 pMatch += 4;
 203         }
 204 #endif
 205
 206         if ((pIn < (pInLimit - 1))
 207                 && (LZ4_read16(pMatch) == LZ4_read16(pIn))) {
 208                 pIn += 2;
 209                 pMatch += 2;
 210         }
 211
 212         if ((pIn < pInLimit) && (*pMatch == *pIn))
 213                 pIn++;
 214
 215         return (unsigned int)(pIn - pStart);
 216 }
 217
 218 typedef enum { noLimit = 0, limitedOutput = 1 } limitedOutput_directive;
 219 typedef enum { byPtr, byU32, byU16 } tableType_t;
 220
 221 typedef enum { noDict = 0, withPrefix64k, usingExtDict } dict_directive;
 222 typedef enum { noDictIssue = 0, dictSmall } dictIssue_directive;
 223
 224 typedef enum { endOnOutputSize = 0, endOnInputSize = 1 } endCondition_directive;
 225 typedef enum { full = 0, partial = 1 } earlyEnd_directive;
 226
 227 #endif