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
40 #include <linux/bitops.h>
41 #include <linux/string.h> /* memset, memcpy */
42
43 #define FORCE_INLINE __always_inline
44
45 /*-************************************
46 * Basic Types
47 **************************************/
48 #include <linux/types.h>
49
50 typedef uint8_t BYTE;
51 typedef uint16_t U16;
52 typedef uint32_t U32;
53 typedef int32_t S32;
54 typedef uint64_t U64;
55 typedef uintptr_t uptrval;
56
57 /*-************************************
58 * Architecture specifics
59 **************************************/
60 #if defined(CONFIG_64BIT)
61 #define LZ4_ARCH64 1
62 #else
63 #define LZ4_ARCH64 0
64 #endif
65
66 #if defined(__LITTLE_ENDIAN)
67 #define LZ4_LITTLE_ENDIAN 1
68 #else
69 #define LZ4_LITTLE_ENDIAN 0
70 #endif
71
72 /*-************************************
73 * Constants
74 **************************************/
75 #define MINMATCH 4
76
77 #define WILDCOPYLENGTH 8
78 #define LASTLITERALS 5
79 #define MFLIMIT (WILDCOPYLENGTH + MINMATCH)
80 /*
81 * ensure it's possible to write 2 x wildcopyLength
82 * without overflowing output buffer
83 */
84 #define MATCH_SAFEGUARD_DISTANCE ((2 * WILDCOPYLENGTH) - MINMATCH)
85
86 /* Increase this value ==> compression run slower on incompressible data */
87 #define LZ4_SKIPTRIGGER 6
88
89 #define HASH_UNIT sizeof(size_t)
90
91 #define KB (1 << 10)
92 #define MB (1 << 20)
93 #define GB (1U << 30)
94
95 #define MAXD_LOG 16
96 #define MAX_DISTANCE ((1 << MAXD_LOG) - 1)
97 #define STEPSIZE sizeof(size_t)
98
99 #define ML_BITS 4
100 #define ML_MASK ((1U << ML_BITS) - 1)
101 #define RUN_BITS (8 - ML_BITS)
102 #define RUN_MASK ((1U << RUN_BITS) - 1)
103
104 /*-************************************
105 * Reading and writing into memory
106 **************************************/
107 static FORCE_INLINE U16 LZ4_read16(const void *ptr)
108 {
109 return get_unaligned((const U16 *)ptr);
110 }
111
112 static FORCE_INLINE U32 LZ4_read32(const void *ptr)
113 {
114 return get_unaligned((const U32 *)ptr);
115 }
116
117 static FORCE_INLINE size_t LZ4_read_ARCH(const void *ptr)
118 {
119 return get_unaligned((const size_t *)ptr);
120 }
121
122 static FORCE_INLINE void LZ4_write16(void *memPtr, U16 value)
123 {
124 put_unaligned(value, (U16 *)memPtr);
125 }
126
127 static FORCE_INLINE void LZ4_write32(void *memPtr, U32 value)
128 {
129 put_unaligned(value, (U32 *)memPtr);
130 }
131
132 static FORCE_INLINE U16 LZ4_readLE16(const void *memPtr)
133 {
134 return get_unaligned_le16(memPtr);
135 }
136
137 static FORCE_INLINE void LZ4_writeLE16(void *memPtr, U16 value)
138 {
139 return put_unaligned_le16(value, memPtr);
140 }
141
142 /*
143 * LZ4 relies on memcpy with a constant size being inlined. In freestanding
144 * environments, the compiler can't assume the implementation of memcpy() is
145 * standard compliant, so apply its specialized memcpy() inlining logic. When
146 * possible, use __builtin_memcpy() to tell the compiler to analyze memcpy()
147 * as-if it were standard compliant, so it can inline it in freestanding
148 * environments. This is needed when decompressing the Linux Kernel, for example.
149 */
150 #define LZ4_memcpy(dst, src, size) __builtin_memcpy(dst, src, size)
151 #define LZ4_memmove(dst, src, size) __builtin_memmove(dst, src, size)
152
153 static FORCE_INLINE void LZ4_copy8(void *dst, const void *src)
154 {
155 #if LZ4_ARCH64
156 U64 a = get_unaligned((const U64 *)src);
157
158 put_unaligned(a, (U64 *)dst);
159 #else
160 U32 a = get_unaligned((const U32 *)src);
161 U32 b = get_unaligned((const U32 *)src + 1);
162
163 put_unaligned(a, (U32 *)dst);
164 put_unaligned(b, (U32 *)dst + 1);
165 #endif
166 }
167
168 /*
169 * customized variant of memcpy,
170 * which can overwrite up to 7 bytes beyond dstEnd
171 */
172 static FORCE_INLINE void LZ4_wildCopy(void *dstPtr,
173 const void *srcPtr, void *dstEnd)
174 {
175 BYTE *d = (BYTE *)dstPtr;
176 const BYTE *s = (const BYTE *)srcPtr;
177 BYTE *const e = (BYTE *)dstEnd;
178
179 do {
180 LZ4_copy8(d, s);
181 d += 8;
182 s += 8;
183 } while (d < e);
184 }
185
186 static FORCE_INLINE unsigned int LZ4_NbCommonBytes(register size_t val)
187 {
188 #if LZ4_LITTLE_ENDIAN
189 return __ffs(val) >> 3;
190 #else
191 return (BITS_PER_LONG - 1 - __fls(val)) >> 3;
192 #endif
193 }
194
195 static FORCE_INLINE unsigned int LZ4_count(
196 const BYTE *pIn,
197 const BYTE *pMatch,
198 const BYTE *pInLimit)
199 {
200 const BYTE *const pStart = pIn;
201
202 while (likely(pIn < pInLimit - (STEPSIZE - 1))) {
203 size_t const diff = LZ4_read_ARCH(pMatch) ^ LZ4_read_ARCH(pIn);
204
205 if (!diff) {
206 pIn += STEPSIZE;
207 pMatch += STEPSIZE;
208 continue;
209 }
210
211 pIn += LZ4_NbCommonBytes(diff);
212
213 return (unsigned int)(pIn - pStart);
214 }
215
216 #if LZ4_ARCH64
217 if ((pIn < (pInLimit - 3))
218 && (LZ4_read32(pMatch) == LZ4_read32(pIn))) {
219 pIn += 4;
220 pMatch += 4;
221 }
222 #endif
223
224 if ((pIn < (pInLimit - 1))
225 && (LZ4_read16(pMatch) == LZ4_read16(pIn))) {
226 pIn += 2;
227 pMatch += 2;
228 }
229
230 if ((pIn < pInLimit) && (*pMatch == *pIn))
231 pIn++;
232
233 return (unsigned int)(pIn - pStart);
234 }
235
236 typedef enum { noLimit = 0, limitedOutput = 1 } limitedOutput_directive;
237 typedef enum { byPtr, byU32, byU16 } tableType_t;
238
239 typedef enum { noDict = 0, withPrefix64k, usingExtDict } dict_directive;
240 typedef enum { noDictIssue = 0, dictSmall } dictIssue_directive;
241
242 typedef enum { endOnOutputSize = 0, endOnInputSize = 1 } endCondition_directive;
243 typedef enum { decode_full_block = 0, partial_decode = 1 } earlyEnd_directive;
244
245 #define LZ4_STATIC_ASSERT(c) BUILD_BUG_ON(!(c))
246
247 #endif
248
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.