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