1*4882a593Smuzhiyun /* SPDX-License-Identifier: GPL-2.0 */ 2*4882a593Smuzhiyun 3*4882a593Smuzhiyun /* Try to choose an implementation variant via Kconfig */ 4*4882a593Smuzhiyun #ifdef CONFIG_CRC32_SLICEBY8 5*4882a593Smuzhiyun # define CRC_LE_BITS 64 6*4882a593Smuzhiyun # define CRC_BE_BITS 64 7*4882a593Smuzhiyun #endif 8*4882a593Smuzhiyun #ifdef CONFIG_CRC32_SLICEBY4 9*4882a593Smuzhiyun # define CRC_LE_BITS 32 10*4882a593Smuzhiyun # define CRC_BE_BITS 32 11*4882a593Smuzhiyun #endif 12*4882a593Smuzhiyun #ifdef CONFIG_CRC32_SARWATE 13*4882a593Smuzhiyun # define CRC_LE_BITS 8 14*4882a593Smuzhiyun # define CRC_BE_BITS 8 15*4882a593Smuzhiyun #endif 16*4882a593Smuzhiyun #ifdef CONFIG_CRC32_BIT 17*4882a593Smuzhiyun # define CRC_LE_BITS 1 18*4882a593Smuzhiyun # define CRC_BE_BITS 1 19*4882a593Smuzhiyun #endif 20*4882a593Smuzhiyun 21*4882a593Smuzhiyun /* 22*4882a593Smuzhiyun * How many bits at a time to use. Valid values are 1, 2, 4, 8, 32 and 64. 23*4882a593Smuzhiyun * For less performance-sensitive, use 4 or 8 to save table size. 24*4882a593Smuzhiyun * For larger systems choose same as CPU architecture as default. 25*4882a593Smuzhiyun * This works well on X86_64, SPARC64 systems. This may require some 26*4882a593Smuzhiyun * elaboration after experiments with other architectures. 27*4882a593Smuzhiyun */ 28*4882a593Smuzhiyun #ifndef CRC_LE_BITS 29*4882a593Smuzhiyun # ifdef CONFIG_64BIT 30*4882a593Smuzhiyun # define CRC_LE_BITS 64 31*4882a593Smuzhiyun # else 32*4882a593Smuzhiyun # define CRC_LE_BITS 32 33*4882a593Smuzhiyun # endif 34*4882a593Smuzhiyun #endif 35*4882a593Smuzhiyun #ifndef CRC_BE_BITS 36*4882a593Smuzhiyun # ifdef CONFIG_64BIT 37*4882a593Smuzhiyun # define CRC_BE_BITS 64 38*4882a593Smuzhiyun # else 39*4882a593Smuzhiyun # define CRC_BE_BITS 32 40*4882a593Smuzhiyun # endif 41*4882a593Smuzhiyun #endif 42*4882a593Smuzhiyun 43*4882a593Smuzhiyun /* 44*4882a593Smuzhiyun * Little-endian CRC computation. Used with serial bit streams sent 45*4882a593Smuzhiyun * lsbit-first. Be sure to use cpu_to_le32() to append the computed CRC. 46*4882a593Smuzhiyun */ 47*4882a593Smuzhiyun #if CRC_LE_BITS > 64 || CRC_LE_BITS < 1 || CRC_LE_BITS == 16 || \ 48*4882a593Smuzhiyun CRC_LE_BITS & CRC_LE_BITS-1 49*4882a593Smuzhiyun # error "CRC_LE_BITS must be one of {1, 2, 4, 8, 32, 64}" 50*4882a593Smuzhiyun #endif 51*4882a593Smuzhiyun 52*4882a593Smuzhiyun /* 53*4882a593Smuzhiyun * Big-endian CRC computation. Used with serial bit streams sent 54*4882a593Smuzhiyun * msbit-first. Be sure to use cpu_to_be32() to append the computed CRC. 55*4882a593Smuzhiyun */ 56*4882a593Smuzhiyun #if CRC_BE_BITS > 64 || CRC_BE_BITS < 1 || CRC_BE_BITS == 16 || \ 57*4882a593Smuzhiyun CRC_BE_BITS & CRC_BE_BITS-1 58*4882a593Smuzhiyun # error "CRC_BE_BITS must be one of {1, 2, 4, 8, 32, 64}" 59*4882a593Smuzhiyun #endif 60