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Linux kernel mirror (for testing)
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linux
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
48typedef uint8_t BYTE;
49typedef uint16_t U16;
50typedef uint32_t U32;
51typedef int32_t S32;
52typedef uint64_t U64;
53typedef 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 * ensure it's possible to write 2 x wildcopyLength
80 * without overflowing output buffer
81 */
82#define MATCH_SAFEGUARD_DISTANCE ((2 * WILDCOPYLENGTH) - MINMATCH)
83
84/* Increase this value ==> compression run slower on incompressible data */
85#define LZ4_SKIPTRIGGER 6
86
87#define HASH_UNIT sizeof(size_t)
88
89#define KB (1 << 10)
90#define MB (1 << 20)
91#define GB (1U << 30)
92
93#define MAXD_LOG 16
94#define MAX_DISTANCE ((1 << MAXD_LOG) - 1)
95#define STEPSIZE sizeof(size_t)
96
97#define ML_BITS 4
98#define ML_MASK ((1U << ML_BITS) - 1)
99#define RUN_BITS (8 - ML_BITS)
100#define RUN_MASK ((1U << RUN_BITS) - 1)
101
102/*-************************************
103 * Reading and writing into memory
104 **************************************/
105static FORCE_INLINE U16 LZ4_read16(const void *ptr)
106{
107 return get_unaligned((const U16 *)ptr);
108}
109
110static FORCE_INLINE U32 LZ4_read32(const void *ptr)
111{
112 return get_unaligned((const U32 *)ptr);
113}
114
115static FORCE_INLINE size_t LZ4_read_ARCH(const void *ptr)
116{
117 return get_unaligned((const size_t *)ptr);
118}
119
120static FORCE_INLINE void LZ4_write16(void *memPtr, U16 value)
121{
122 put_unaligned(value, (U16 *)memPtr);
123}
124
125static FORCE_INLINE void LZ4_write32(void *memPtr, U32 value)
126{
127 put_unaligned(value, (U32 *)memPtr);
128}
129
130static FORCE_INLINE U16 LZ4_readLE16(const void *memPtr)
131{
132 return get_unaligned_le16(memPtr);
133}
134
135static FORCE_INLINE void LZ4_writeLE16(void *memPtr, U16 value)
136{
137 return put_unaligned_le16(value, memPtr);
138}
139
140static FORCE_INLINE void LZ4_copy8(void *dst, const void *src)
141{
142#if LZ4_ARCH64
143 U64 a = get_unaligned((const U64 *)src);
144
145 put_unaligned(a, (U64 *)dst);
146#else
147 U32 a = get_unaligned((const U32 *)src);
148 U32 b = get_unaligned((const U32 *)src + 1);
149
150 put_unaligned(a, (U32 *)dst);
151 put_unaligned(b, (U32 *)dst + 1);
152#endif
153}
154
155/*
156 * customized variant of memcpy,
157 * which can overwrite up to 7 bytes beyond dstEnd
158 */
159static FORCE_INLINE void LZ4_wildCopy(void *dstPtr,
160 const void *srcPtr, void *dstEnd)
161{
162 BYTE *d = (BYTE *)dstPtr;
163 const BYTE *s = (const BYTE *)srcPtr;
164 BYTE *const e = (BYTE *)dstEnd;
165
166 do {
167 LZ4_copy8(d, s);
168 d += 8;
169 s += 8;
170 } while (d < e);
171}
172
173static FORCE_INLINE unsigned int LZ4_NbCommonBytes(register size_t val)
174{
175#if LZ4_LITTLE_ENDIAN
176 return __ffs(val) >> 3;
177#else
178 return (BITS_PER_LONG - 1 - __fls(val)) >> 3;
179#endif
180}
181
182static FORCE_INLINE unsigned int LZ4_count(
183 const BYTE *pIn,
184 const BYTE *pMatch,
185 const BYTE *pInLimit)
186{
187 const BYTE *const pStart = pIn;
188
189 while (likely(pIn < pInLimit - (STEPSIZE - 1))) {
190 size_t const diff = LZ4_read_ARCH(pMatch) ^ LZ4_read_ARCH(pIn);
191
192 if (!diff) {
193 pIn += STEPSIZE;
194 pMatch += STEPSIZE;
195 continue;
196 }
197
198 pIn += LZ4_NbCommonBytes(diff);
199
200 return (unsigned int)(pIn - pStart);
201 }
202
203#if LZ4_ARCH64
204 if ((pIn < (pInLimit - 3))
205 && (LZ4_read32(pMatch) == LZ4_read32(pIn))) {
206 pIn += 4;
207 pMatch += 4;
208 }
209#endif
210
211 if ((pIn < (pInLimit - 1))
212 && (LZ4_read16(pMatch) == LZ4_read16(pIn))) {
213 pIn += 2;
214 pMatch += 2;
215 }
216
217 if ((pIn < pInLimit) && (*pMatch == *pIn))
218 pIn++;
219
220 return (unsigned int)(pIn - pStart);
221}
222
223typedef enum { noLimit = 0, limitedOutput = 1 } limitedOutput_directive;
224typedef enum { byPtr, byU32, byU16 } tableType_t;
225
226typedef enum { noDict = 0, withPrefix64k, usingExtDict } dict_directive;
227typedef enum { noDictIssue = 0, dictSmall } dictIssue_directive;
228
229typedef enum { endOnOutputSize = 0, endOnInputSize = 1 } endCondition_directive;
230typedef enum { decode_full_block = 0, partial_decode = 1 } earlyEnd_directive;
231
232#define LZ4_STATIC_ASSERT(c) BUILD_BUG_ON(!(c))
233
234#endif