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linux
1/*
2 * crc32.h
3 * See linux/lib/crc32.c for license and changes
4 */
5#ifndef _LINUX_CRC32_H
6#define _LINUX_CRC32_H
7
8#include <linux/types.h>
9#include <linux/bitrev.h>
10
11u32 crc32_le_arch(u32 crc, const u8 *p, size_t len);
12u32 crc32_le_base(u32 crc, const u8 *p, size_t len);
13u32 crc32_be_arch(u32 crc, const u8 *p, size_t len);
14u32 crc32_be_base(u32 crc, const u8 *p, size_t len);
15u32 crc32c_arch(u32 crc, const u8 *p, size_t len);
16u32 crc32c_base(u32 crc, const u8 *p, size_t len);
17
18static inline u32 crc32_le(u32 crc, const void *p, size_t len)
19{
20 if (IS_ENABLED(CONFIG_CRC32_ARCH))
21 return crc32_le_arch(crc, p, len);
22 return crc32_le_base(crc, p, len);
23}
24
25static inline u32 crc32_be(u32 crc, const void *p, size_t len)
26{
27 if (IS_ENABLED(CONFIG_CRC32_ARCH))
28 return crc32_be_arch(crc, p, len);
29 return crc32_be_base(crc, p, len);
30}
31
32static inline u32 crc32c(u32 crc, const void *p, size_t len)
33{
34 if (IS_ENABLED(CONFIG_CRC32_ARCH))
35 return crc32c_arch(crc, p, len);
36 return crc32c_base(crc, p, len);
37}
38
39/*
40 * crc32_optimizations() returns flags that indicate which CRC32 library
41 * functions are using architecture-specific optimizations. Unlike
42 * IS_ENABLED(CONFIG_CRC32_ARCH) it takes into account the different CRC32
43 * variants and also whether any needed CPU features are available at runtime.
44 */
45#define CRC32_LE_OPTIMIZATION BIT(0) /* crc32_le() is optimized */
46#define CRC32_BE_OPTIMIZATION BIT(1) /* crc32_be() is optimized */
47#define CRC32C_OPTIMIZATION BIT(2) /* crc32c() is optimized */
48#if IS_ENABLED(CONFIG_CRC32_ARCH)
49u32 crc32_optimizations(void);
50#else
51static inline u32 crc32_optimizations(void) { return 0; }
52#endif
53
54/**
55 * crc32_le_combine - Combine two crc32 check values into one. For two
56 * sequences of bytes, seq1 and seq2 with lengths len1
57 * and len2, crc32_le() check values were calculated
58 * for each, crc1 and crc2.
59 *
60 * @crc1: crc32 of the first block
61 * @crc2: crc32 of the second block
62 * @len2: length of the second block
63 *
64 * Return: The crc32_le() check value of seq1 and seq2 concatenated,
65 * requiring only crc1, crc2, and len2. Note: If seq_full denotes
66 * the concatenated memory area of seq1 with seq2, and crc_full
67 * the crc32_le() value of seq_full, then crc_full ==
68 * crc32_le_combine(crc1, crc2, len2) when crc_full was seeded
69 * with the same initializer as crc1, and crc2 seed was 0. See
70 * also crc32_combine_test().
71 */
72u32 crc32_le_shift(u32 crc, size_t len);
73
74static inline u32 crc32_le_combine(u32 crc1, u32 crc2, size_t len2)
75{
76 return crc32_le_shift(crc1, len2) ^ crc2;
77}
78
79u32 crc32c_shift(u32 crc, size_t len);
80
81/**
82 * crc32c_combine - Combine two crc32c check values into one. For two sequences
83 * of bytes, seq1 and seq2 with lengths len1 and len2, crc32c()
84 * check values were calculated for each, crc1 and crc2.
85 *
86 * @crc1: crc32c of the first block
87 * @crc2: crc32c of the second block
88 * @len2: length of the second block
89 *
90 * Return: The crc32c() check value of seq1 and seq2 concatenated, requiring
91 * only crc1, crc2, and len2. Note: If seq_full denotes the concatenated
92 * memory area of seq1 with seq2, and crc_full the crc32c() value of
93 * seq_full, then crc_full == crc32c_combine(crc1, crc2, len2) when
94 * crc_full was seeded with the same initializer as crc1, and crc2 seed
95 * was 0. See also crc_combine_test().
96 */
97static inline u32 crc32c_combine(u32 crc1, u32 crc2, size_t len2)
98{
99 return crc32c_shift(crc1, len2) ^ crc2;
100}
101
102#define crc32(seed, data, length) crc32_le(seed, (unsigned char const *)(data), length)
103
104/*
105 * Helpers for hash table generation of ethernet nics:
106 *
107 * Ethernet sends the least significant bit of a byte first, thus crc32_le
108 * is used. The output of crc32_le is bit reversed [most significant bit
109 * is in bit nr 0], thus it must be reversed before use. Except for
110 * nics that bit swap the result internally...
111 */
112#define ether_crc(length, data) bitrev32(crc32_le(~0, data, length))
113#define ether_crc_le(length, data) crc32_le(~0, data, length)
114
115#endif /* _LINUX_CRC32_H */