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 
crc32_le_combine(u32 crc1,u32 crc2,size_t len2)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 
__crc32c_le_combine(u32 crc1,u32 crc2,size_t len2)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 */
80