1 /**
2 * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
3 * All rights reserved.
4 *
5 * This source code is licensed under the BSD-style license found in the
6 * LICENSE file in the root directory of https://github.com/facebook/zstd.
7 *
8 * This program is free software; you can redistribute it and/or modify it under
9 * the terms of the GNU General Public License version 2 as published by the
10 * Free Software Foundation. This program is dual-licensed; you may select
11 * either version 2 of the GNU General Public License ("GPL") or BSD license
12 * ("BSD").
13 */
14
15 #ifndef MEM_H_MODULE
16 #define MEM_H_MODULE
17
18 /*-****************************************
19 * Dependencies
20 ******************************************/
21 #include <asm/unaligned.h>
22 #include <linux/string.h> /* memcpy */
23 #include <linux/types.h> /* size_t, ptrdiff_t */
24
25 /*-****************************************
26 * Compiler specifics
27 ******************************************/
28 #define ZSTD_STATIC static __inline __attribute__((unused))
29
30 /*-**************************************************************
31 * Basic Types
32 *****************************************************************/
33 typedef uint8_t BYTE;
34 typedef uint16_t U16;
35 typedef int16_t S16;
36 typedef uint32_t U32;
37 typedef int32_t S32;
38 typedef uint64_t U64;
39 typedef int64_t S64;
40 typedef ptrdiff_t iPtrDiff;
41 typedef uintptr_t uPtrDiff;
42
43 /*-**************************************************************
44 * Memory I/O
45 *****************************************************************/
ZSTD_32bits(void)46 ZSTD_STATIC unsigned ZSTD_32bits(void) { return sizeof(size_t) == 4; }
ZSTD_64bits(void)47 ZSTD_STATIC unsigned ZSTD_64bits(void) { return sizeof(size_t) == 8; }
48
49 #if defined(__LITTLE_ENDIAN)
50 #define ZSTD_LITTLE_ENDIAN 1
51 #else
52 #define ZSTD_LITTLE_ENDIAN 0
53 #endif
54
ZSTD_isLittleEndian(void)55 ZSTD_STATIC unsigned ZSTD_isLittleEndian(void) { return ZSTD_LITTLE_ENDIAN; }
56
ZSTD_read16(const void * memPtr)57 ZSTD_STATIC U16 ZSTD_read16(const void *memPtr) { return get_unaligned((const U16 *)memPtr); }
58
ZSTD_read32(const void * memPtr)59 ZSTD_STATIC U32 ZSTD_read32(const void *memPtr) { return get_unaligned((const U32 *)memPtr); }
60
ZSTD_read64(const void * memPtr)61 ZSTD_STATIC U64 ZSTD_read64(const void *memPtr) { return get_unaligned((const U64 *)memPtr); }
62
ZSTD_readST(const void * memPtr)63 ZSTD_STATIC size_t ZSTD_readST(const void *memPtr) { return get_unaligned((const size_t *)memPtr); }
64
ZSTD_write16(void * memPtr,U16 value)65 ZSTD_STATIC void ZSTD_write16(void *memPtr, U16 value) { put_unaligned(value, (U16 *)memPtr); }
66
ZSTD_write32(void * memPtr,U32 value)67 ZSTD_STATIC void ZSTD_write32(void *memPtr, U32 value) { put_unaligned(value, (U32 *)memPtr); }
68
ZSTD_write64(void * memPtr,U64 value)69 ZSTD_STATIC void ZSTD_write64(void *memPtr, U64 value) { put_unaligned(value, (U64 *)memPtr); }
70
71 /*=== Little endian r/w ===*/
72
ZSTD_readLE16(const void * memPtr)73 ZSTD_STATIC U16 ZSTD_readLE16(const void *memPtr) { return get_unaligned_le16(memPtr); }
74
ZSTD_writeLE16(void * memPtr,U16 val)75 ZSTD_STATIC void ZSTD_writeLE16(void *memPtr, U16 val) { put_unaligned_le16(val, memPtr); }
76
ZSTD_readLE24(const void * memPtr)77 ZSTD_STATIC U32 ZSTD_readLE24(const void *memPtr) { return ZSTD_readLE16(memPtr) + (((const BYTE *)memPtr)[2] << 16); }
78
ZSTD_writeLE24(void * memPtr,U32 val)79 ZSTD_STATIC void ZSTD_writeLE24(void *memPtr, U32 val)
80 {
81 ZSTD_writeLE16(memPtr, (U16)val);
82 ((BYTE *)memPtr)[2] = (BYTE)(val >> 16);
83 }
84
ZSTD_readLE32(const void * memPtr)85 ZSTD_STATIC U32 ZSTD_readLE32(const void *memPtr) { return get_unaligned_le32(memPtr); }
86
ZSTD_writeLE32(void * memPtr,U32 val32)87 ZSTD_STATIC void ZSTD_writeLE32(void *memPtr, U32 val32) { put_unaligned_le32(val32, memPtr); }
88
ZSTD_readLE64(const void * memPtr)89 ZSTD_STATIC U64 ZSTD_readLE64(const void *memPtr) { return get_unaligned_le64(memPtr); }
90
ZSTD_writeLE64(void * memPtr,U64 val64)91 ZSTD_STATIC void ZSTD_writeLE64(void *memPtr, U64 val64) { put_unaligned_le64(val64, memPtr); }
92
ZSTD_readLEST(const void * memPtr)93 ZSTD_STATIC size_t ZSTD_readLEST(const void *memPtr)
94 {
95 if (ZSTD_32bits())
96 return (size_t)ZSTD_readLE32(memPtr);
97 else
98 return (size_t)ZSTD_readLE64(memPtr);
99 }
100
ZSTD_writeLEST(void * memPtr,size_t val)101 ZSTD_STATIC void ZSTD_writeLEST(void *memPtr, size_t val)
102 {
103 if (ZSTD_32bits())
104 ZSTD_writeLE32(memPtr, (U32)val);
105 else
106 ZSTD_writeLE64(memPtr, (U64)val);
107 }
108
109 /*=== Big endian r/w ===*/
110
ZSTD_readBE32(const void * memPtr)111 ZSTD_STATIC U32 ZSTD_readBE32(const void *memPtr) { return get_unaligned_be32(memPtr); }
112
ZSTD_writeBE32(void * memPtr,U32 val32)113 ZSTD_STATIC void ZSTD_writeBE32(void *memPtr, U32 val32) { put_unaligned_be32(val32, memPtr); }
114
ZSTD_readBE64(const void * memPtr)115 ZSTD_STATIC U64 ZSTD_readBE64(const void *memPtr) { return get_unaligned_be64(memPtr); }
116
ZSTD_writeBE64(void * memPtr,U64 val64)117 ZSTD_STATIC void ZSTD_writeBE64(void *memPtr, U64 val64) { put_unaligned_be64(val64, memPtr); }
118
ZSTD_readBEST(const void * memPtr)119 ZSTD_STATIC size_t ZSTD_readBEST(const void *memPtr)
120 {
121 if (ZSTD_32bits())
122 return (size_t)ZSTD_readBE32(memPtr);
123 else
124 return (size_t)ZSTD_readBE64(memPtr);
125 }
126
ZSTD_writeBEST(void * memPtr,size_t val)127 ZSTD_STATIC void ZSTD_writeBEST(void *memPtr, size_t val)
128 {
129 if (ZSTD_32bits())
130 ZSTD_writeBE32(memPtr, (U32)val);
131 else
132 ZSTD_writeBE64(memPtr, (U64)val);
133 }
134
135 /* function safe only for comparisons */
ZSTD_readMINMATCH(const void * memPtr,U32 length)136 ZSTD_STATIC U32 ZSTD_readMINMATCH(const void *memPtr, U32 length)
137 {
138 switch (length) {
139 default:
140 case 4: return ZSTD_read32(memPtr);
141 case 3:
142 if (ZSTD_isLittleEndian())
143 return ZSTD_read32(memPtr) << 8;
144 else
145 return ZSTD_read32(memPtr) >> 8;
146 }
147 }
148
149 #endif /* MEM_H_MODULE */
150