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
11 u32 __pure crc32_le(u32 crc, unsigned char const *p, size_t len);
12 u32 __pure crc32_le_base(u32 crc, unsigned char const *p, size_t len);
13 u32 __pure crc32_be(u32 crc, unsigned char const *p, size_t len);
14 u32 __pure crc32_be_base(u32 crc, unsigned char const *p, size_t len);
15
16 /**
17 * crc32_le_combine - Combine two crc32 check values into one. For two
18 * sequences of bytes, seq1 and seq2 with lengths len1
19 * and len2, crc32_le() check values were calculated
20 * for each, crc1 and crc2.
21 *
22 * @crc1: crc32 of the first block
23 * @crc2: crc32 of the second block
24 * @len2: length of the second block
25 *
26 * Return: The crc32_le() check value of seq1 and seq2 concatenated,
27 * requiring only crc1, crc2, and len2. Note: If seq_full denotes
28 * the concatenated memory area of seq1 with seq2, and crc_full
29 * the crc32_le() value of seq_full, then crc_full ==
30 * crc32_le_combine(crc1, crc2, len2) when crc_full was seeded
31 * with the same initializer as crc1, and crc2 seed was 0. See
32 * also crc32_combine_test().
33 */
34 u32 __attribute_const__ crc32_le_shift(u32 crc, size_t len);
35
36 static inline u32 crc32_le_combine(u32 crc1, u32 crc2, size_t len2)
37 {
38 return crc32_le_shift(crc1, len2) ^ crc2;
39 }
40
41 u32 __pure __crc32c_le(u32 crc, unsigned char const *p, size_t len);
42 u32 __pure __crc32c_le_base(u32 crc, unsigned char const *p, size_t len);
43
44 /**
45 * __crc32c_le_combine - Combine two crc32c check values into one. For two
46 * sequences of bytes, seq1 and seq2 with lengths len1
47 * and len2, __crc32c_le() check values were calculated
48 * for each, crc1 and crc2.
49 *
50 * @crc1: crc32c of the first block
51 * @crc2: crc32c of the second block
52 * @len2: length of the second block
53 *
54 * Return: The __crc32c_le() check value of seq1 and seq2 concatenated,
55 * requiring only crc1, crc2, and len2. Note: If seq_full denotes
56 * the concatenated memory area of seq1 with seq2, and crc_full
57 * the __crc32c_le() value of seq_full, then crc_full ==
58 * __crc32c_le_combine(crc1, crc2, len2) when crc_full was
59 * seeded with the same initializer as crc1, and crc2 seed
60 * was 0. See also crc32c_combine_test().
61 */
62 u32 __attribute_const__ __crc32c_le_shift(u32 crc, size_t len);
63
64 static inline u32 __crc32c_le_combine(u32 crc1, u32 crc2, size_t len2)
65 {
66 return __crc32c_le_shift(crc1, len2) ^ crc2;
67 }
68
69 #define crc32(seed, data, length) crc32_le(seed, (unsigned char const *)(data), length)
70
71 /*
72 * Helpers for hash table generation of ethernet nics:
73 *
74 * Ethernet sends the least significant bit of a byte first, thus crc32_le
75 * is used. The output of crc32_le is bit reversed [most significant bit
76 * is in bit nr 0], thus it must be reversed before use. Except for
77 * nics that bit swap the result internally...
78 */
79 #define ether_crc(length, data) bitrev32(crc32_le(~0, data, length))
80 #define ether_crc_le(length, data) crc32_le(~0, data, length)
81
82 #endif /* _LINUX_CRC32_H */
83
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