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