Commit | Line | Data |
---|---|---|
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 | ||
324eb0f1 BP |
9 | /* |
10 | * How many bits at a time to use. Valid values are 1, 2, 4, 8, 32 and 64. | |
11 | * For less performance-sensitive, use 4 or 8 to save table size. | |
12 | * For larger systems choose same as CPU architecture as default. | |
13 | * This works well on X86_64, SPARC64 systems. This may require some | |
14 | * elaboration after experiments with other architectures. | |
15 | */ | |
e30c7a8f | 16 | #ifndef CRC_LE_BITS |
324eb0f1 BP |
17 | # ifdef CONFIG_64BIT |
18 | # define CRC_LE_BITS 64 | |
19 | # else | |
20 | # define CRC_LE_BITS 32 | |
21 | # endif | |
1da177e4 LT |
22 | #endif |
23 | #ifndef CRC_BE_BITS | |
324eb0f1 BP |
24 | # ifdef CONFIG_64BIT |
25 | # define CRC_BE_BITS 64 | |
26 | # else | |
27 | # define CRC_BE_BITS 32 | |
28 | # endif | |
1da177e4 LT |
29 | #endif |
30 | ||
31 | /* | |
32 | * Little-endian CRC computation. Used with serial bit streams sent | |
33 | * lsbit-first. Be sure to use cpu_to_le32() to append the computed CRC. | |
34 | */ | |
324eb0f1 | 35 | #if CRC_LE_BITS > 64 || CRC_LE_BITS < 1 || CRC_LE_BITS == 16 || \ |
9a1dbf6a | 36 | CRC_LE_BITS & CRC_LE_BITS-1 |
324eb0f1 | 37 | # error "CRC_LE_BITS must be one of {1, 2, 4, 8, 32, 64}" |
1da177e4 LT |
38 | #endif |
39 | ||
40 | /* | |
41 | * Big-endian CRC computation. Used with serial bit streams sent | |
42 | * msbit-first. Be sure to use cpu_to_be32() to append the computed CRC. | |
43 | */ | |
324eb0f1 | 44 | #if CRC_BE_BITS > 64 || CRC_BE_BITS < 1 || CRC_BE_BITS == 16 || \ |
9a1dbf6a | 45 | CRC_BE_BITS & CRC_BE_BITS-1 |
324eb0f1 | 46 | # error "CRC_BE_BITS must be one of {1, 2, 4, 8, 32, 64}" |
1da177e4 | 47 | #endif |