| /* |
| * There are multiple 16-bit CRC polynomials in common use, but this is |
| * *the* standard CRC-32 polynomial, first popularized by Ethernet. |
| * 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 |
| */ |
| #define CRCPOLY_LE 0xedb88320 |
| #define CRCPOLY_BE 0x04c11db7 |
| |
| /* |
| * This is the CRC32c polynomial, as outlined by Castagnoli. |
| * 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+ |
| * x^8+x^6+x^0 |
| */ |
| #define CRC32C_POLY_LE 0x82F63B78 |
| |
| /* Try to choose an implementation variant via Kconfig */ |
| #ifdef CONFIG_CRC32_SLICEBY8 |
| # define CRC_LE_BITS 64 |
| # define CRC_BE_BITS 64 |
| #endif |
| #ifdef CONFIG_CRC32_SLICEBY4 |
| # define CRC_LE_BITS 32 |
| # define CRC_BE_BITS 32 |
| #endif |
| #ifdef CONFIG_CRC32_SARWATE |
| # define CRC_LE_BITS 8 |
| # define CRC_BE_BITS 8 |
| #endif |
| #ifdef CONFIG_CRC32_BIT |
| # define CRC_LE_BITS 1 |
| # define CRC_BE_BITS 1 |
| #endif |
| |
| /* |
| * How many bits at a time to use. Valid values are 1, 2, 4, 8, 32 and 64. |
| * For less performance-sensitive, use 4 or 8 to save table size. |
| * For larger systems choose same as CPU architecture as default. |
| * This works well on X86_64, SPARC64 systems. This may require some |
| * elaboration after experiments with other architectures. |
| */ |
| #ifndef CRC_LE_BITS |
| # ifdef CONFIG_64BIT |
| # define CRC_LE_BITS 64 |
| # else |
| # define CRC_LE_BITS 32 |
| # endif |
| #endif |
| #ifndef CRC_BE_BITS |
| # ifdef CONFIG_64BIT |
| # define CRC_BE_BITS 64 |
| # else |
| # define CRC_BE_BITS 32 |
| # endif |
| #endif |
| |
| /* |
| * Little-endian CRC computation. Used with serial bit streams sent |
| * lsbit-first. Be sure to use cpu_to_le32() to append the computed CRC. |
| */ |
| #if CRC_LE_BITS > 64 || CRC_LE_BITS < 1 || CRC_LE_BITS == 16 || \ |
| CRC_LE_BITS & CRC_LE_BITS-1 |
| # error "CRC_LE_BITS must be one of {1, 2, 4, 8, 32, 64}" |
| #endif |
| |
| /* |
| * Big-endian CRC computation. Used with serial bit streams sent |
| * msbit-first. Be sure to use cpu_to_be32() to append the computed CRC. |
| */ |
| #if CRC_BE_BITS > 64 || CRC_BE_BITS < 1 || CRC_BE_BITS == 16 || \ |
| CRC_BE_BITS & CRC_BE_BITS-1 |
| # error "CRC_BE_BITS must be one of {1, 2, 4, 8, 32, 64}" |
| #endif |
