1*0bcfca56SEric Biggers // SPDX-License-Identifier: GPL-2.0 2*0bcfca56SEric Biggers /* 3*0bcfca56SEric Biggers * Normal 64-bit CRC calculation. 4*0bcfca56SEric Biggers * 5*0bcfca56SEric Biggers * This is a basic crc64 implementation following ECMA-182 specification, 6*0bcfca56SEric Biggers * which can be found from, 7*0bcfca56SEric Biggers * https://www.ecma-international.org/publications/standards/Ecma-182.htm 8*0bcfca56SEric Biggers * 9*0bcfca56SEric Biggers * Dr. Ross N. Williams has a great document to introduce the idea of CRC 10*0bcfca56SEric Biggers * algorithm, here the CRC64 code is also inspired by the table-driven 11*0bcfca56SEric Biggers * algorithm and detail example from this paper. This paper can be found 12*0bcfca56SEric Biggers * from, 13*0bcfca56SEric Biggers * http://www.ross.net/crc/download/crc_v3.txt 14*0bcfca56SEric Biggers * 15*0bcfca56SEric Biggers * crc64table[256] is the lookup table of a table-driven 64-bit CRC 16*0bcfca56SEric Biggers * calculation, which is generated by gen_crc64table.c in kernel build 17*0bcfca56SEric Biggers * time. The polynomial of crc64 arithmetic is from ECMA-182 specification 18*0bcfca56SEric Biggers * as well, which is defined as, 19*0bcfca56SEric Biggers * 20*0bcfca56SEric Biggers * x^64 + x^62 + x^57 + x^55 + x^54 + x^53 + x^52 + x^47 + x^46 + x^45 + 21*0bcfca56SEric Biggers * x^40 + x^39 + x^38 + x^37 + x^35 + x^33 + x^32 + x^31 + x^29 + x^27 + 22*0bcfca56SEric Biggers * x^24 + x^23 + x^22 + x^21 + x^19 + x^17 + x^13 + x^12 + x^10 + x^9 + 23*0bcfca56SEric Biggers * x^7 + x^4 + x + 1 24*0bcfca56SEric Biggers * 25*0bcfca56SEric Biggers * crc64nvmetable[256] uses the CRC64 polynomial from the NVME NVM Command Set 26*0bcfca56SEric Biggers * Specification and uses least-significant-bit first bit order: 27*0bcfca56SEric Biggers * 28*0bcfca56SEric Biggers * x^64 + x^63 + x^61 + x^59 + x^58 + x^56 + x^55 + x^52 + x^49 + x^48 + x^47 + 29*0bcfca56SEric Biggers * x^46 + x^44 + x^41 + x^37 + x^36 + x^34 + x^32 + x^31 + x^28 + x^26 + x^23 + 30*0bcfca56SEric Biggers * x^22 + x^19 + x^16 + x^13 + x^12 + x^10 + x^9 + x^6 + x^4 + x^3 + 1 31*0bcfca56SEric Biggers * 32*0bcfca56SEric Biggers * Copyright 2018 SUSE Linux. 33*0bcfca56SEric Biggers * Author: Coly Li <colyli@suse.de> 34*0bcfca56SEric Biggers */ 35*0bcfca56SEric Biggers 36*0bcfca56SEric Biggers #include <linux/module.h> 37*0bcfca56SEric Biggers #include <linux/types.h> 38*0bcfca56SEric Biggers #include <linux/crc64.h> 39*0bcfca56SEric Biggers #include "crc64table.h" 40*0bcfca56SEric Biggers 41*0bcfca56SEric Biggers static inline u64 __maybe_unused 42*0bcfca56SEric Biggers crc64_be_generic(u64 crc, const u8 *p, size_t len) 43*0bcfca56SEric Biggers { 44*0bcfca56SEric Biggers while (len--) 45*0bcfca56SEric Biggers crc = (crc << 8) ^ crc64table[(crc >> 56) ^ *p++]; 46*0bcfca56SEric Biggers return crc; 47*0bcfca56SEric Biggers } 48*0bcfca56SEric Biggers 49*0bcfca56SEric Biggers static inline u64 __maybe_unused 50*0bcfca56SEric Biggers crc64_nvme_generic(u64 crc, const u8 *p, size_t len) 51*0bcfca56SEric Biggers { 52*0bcfca56SEric Biggers while (len--) 53*0bcfca56SEric Biggers crc = (crc >> 8) ^ crc64nvmetable[(crc & 0xff) ^ *p++]; 54*0bcfca56SEric Biggers return crc; 55*0bcfca56SEric Biggers } 56*0bcfca56SEric Biggers 57*0bcfca56SEric Biggers #ifdef CONFIG_CRC64_ARCH 58*0bcfca56SEric Biggers #include "crc64.h" /* $(SRCARCH)/crc64.h */ 59*0bcfca56SEric Biggers #else 60*0bcfca56SEric Biggers #define crc64_be_arch crc64_be_generic 61*0bcfca56SEric Biggers #define crc64_nvme_arch crc64_nvme_generic 62*0bcfca56SEric Biggers #endif 63*0bcfca56SEric Biggers 64*0bcfca56SEric Biggers u64 crc64_be(u64 crc, const void *p, size_t len) 65*0bcfca56SEric Biggers { 66*0bcfca56SEric Biggers return crc64_be_arch(crc, p, len); 67*0bcfca56SEric Biggers } 68*0bcfca56SEric Biggers EXPORT_SYMBOL_GPL(crc64_be); 69*0bcfca56SEric Biggers 70*0bcfca56SEric Biggers u64 crc64_nvme(u64 crc, const void *p, size_t len) 71*0bcfca56SEric Biggers { 72*0bcfca56SEric Biggers return ~crc64_nvme_arch(~crc, p, len); 73*0bcfca56SEric Biggers } 74*0bcfca56SEric Biggers EXPORT_SYMBOL_GPL(crc64_nvme); 75*0bcfca56SEric Biggers 76*0bcfca56SEric Biggers #ifdef crc64_mod_init_arch 77*0bcfca56SEric Biggers static int __init crc64_mod_init(void) 78*0bcfca56SEric Biggers { 79*0bcfca56SEric Biggers crc64_mod_init_arch(); 80*0bcfca56SEric Biggers return 0; 81*0bcfca56SEric Biggers } 82*0bcfca56SEric Biggers subsys_initcall(crc64_mod_init); 83*0bcfca56SEric Biggers 84*0bcfca56SEric Biggers static void __exit crc64_mod_exit(void) 85*0bcfca56SEric Biggers { 86*0bcfca56SEric Biggers } 87*0bcfca56SEric Biggers module_exit(crc64_mod_exit); 88*0bcfca56SEric Biggers #endif 89*0bcfca56SEric Biggers 90*0bcfca56SEric Biggers MODULE_DESCRIPTION("CRC64 library functions"); 91*0bcfca56SEric Biggers MODULE_LICENSE("GPL"); 92