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 
crc32_le_combine(u32 crc1,u32 crc2,size_t len2)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 
__crc32c_le_combine(u32 crc1,u32 crc2,size_t len2)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