/* * 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 [31mCONFIG_CRC32_SLICEBY8[0m # define CRC_LE_BITS 64 # define CRC_BE_BITS 64 #endif #ifdef [31mCONFIG_CRC32_SLICEBY4[0m # define CRC_LE_BITS 32 # define CRC_BE_BITS 32 #endif #ifdef [31mCONFIG_CRC32_SARWATE[0m # define CRC_LE_BITS 8 # define CRC_BE_BITS 8 #endif #ifdef [31mCONFIG_CRC32_BIT[0m # 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 [31mCONFIG_64BIT[0m # define CRC_LE_BITS 64 # else # define CRC_LE_BITS 32 # endif #endif #ifndef CRC_BE_BITS # ifdef [31mCONFIG_64BIT[0m # 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 |