Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * There are multiple 16-bit CRC polynomials in common use, but this is | |
3 | * *the* standard CRC-32 polynomial, first popularized by Ethernet. | |
4 | * x^32+x^26+x^23+x^22+x^16+x^12+x^11+x^10+x^8+x^7+x^5+x^4+x^2+x^1+x^0 | |
5 | */ | |
6 | #define CRCPOLY_LE 0xedb88320 | |
7 | #define CRCPOLY_BE 0x04c11db7 | |
8 | ||
46c5801e DW |
9 | /* |
10 | * This is the CRC32c polynomial, as outlined by Castagnoli. | |
11 | * x^32+x^28+x^27+x^26+x^25+x^23+x^22+x^20+x^19+x^18+x^14+x^13+x^11+x^10+x^9+ | |
12 | * x^8+x^6+x^0 | |
13 | */ | |
14 | #define CRC32C_POLY_LE 0x82F63B78 | |
15 | ||
324eb0f1 BP |
16 | /* |
17 | * How many bits at a time to use. Valid values are 1, 2, 4, 8, 32 and 64. | |
18 | * For less performance-sensitive, use 4 or 8 to save table size. | |
19 | * For larger systems choose same as CPU architecture as default. | |
20 | * This works well on X86_64, SPARC64 systems. This may require some | |
21 | * elaboration after experiments with other architectures. | |
22 | */ | |
e30c7a8f | 23 | #ifndef CRC_LE_BITS |
324eb0f1 BP |
24 | # ifdef CONFIG_64BIT |
25 | # define CRC_LE_BITS 64 | |
26 | # else | |
27 | # define CRC_LE_BITS 32 | |
28 | # endif | |
1da177e4 LT |
29 | #endif |
30 | #ifndef CRC_BE_BITS | |
324eb0f1 BP |
31 | # ifdef CONFIG_64BIT |
32 | # define CRC_BE_BITS 64 | |
33 | # else | |
34 | # define CRC_BE_BITS 32 | |
35 | # endif | |
1da177e4 LT |
36 | #endif |
37 | ||
38 | /* | |
39 | * Little-endian CRC computation. Used with serial bit streams sent | |
40 | * lsbit-first. Be sure to use cpu_to_le32() to append the computed CRC. | |
41 | */ | |
324eb0f1 | 42 | #if CRC_LE_BITS > 64 || CRC_LE_BITS < 1 || CRC_LE_BITS == 16 || \ |
9a1dbf6a | 43 | CRC_LE_BITS & CRC_LE_BITS-1 |
324eb0f1 | 44 | # error "CRC_LE_BITS must be one of {1, 2, 4, 8, 32, 64}" |
1da177e4 LT |
45 | #endif |
46 | ||
47 | /* | |
48 | * Big-endian CRC computation. Used with serial bit streams sent | |
49 | * msbit-first. Be sure to use cpu_to_be32() to append the computed CRC. | |
50 | */ | |
324eb0f1 | 51 | #if CRC_BE_BITS > 64 || CRC_BE_BITS < 1 || CRC_BE_BITS == 16 || \ |
9a1dbf6a | 52 | CRC_BE_BITS & CRC_BE_BITS-1 |
324eb0f1 | 53 | # error "CRC_BE_BITS must be one of {1, 2, 4, 8, 32, 64}" |
1da177e4 | 54 | #endif |