From cbc0a40e17da361a2ada8d669413ccfbd2028f2d Mon Sep 17 00:00:00 2001 From: Keith Busch Date: Thu, 3 Mar 2022 12:13:09 -0800 Subject: lib: add rocksoft model crc64 The NVM Express specification extended data integrity fields to 64 bits using the Rocksoft parameters. Add the poly to the crc64 table generation, and provide a generic library routine implementing the algorithm. The Rocksoft 64-bit CRC model parameters are as follows: Poly: 0xAD93D23594C93659 Initial value: 0xFFFFFFFFFFFFFFFF Reflected Input: True Reflected Output: True Xor Final: 0xFFFFFFFFFFFFFFFF Since this model used reflected bits, the implementation generates the reflected table so the result is ordered consistently. Cc: Christoph Hellwig Cc: Hannes Reinecke Cc: Martin K. Petersen Signed-off-by: Keith Busch Reviewed-by: Martin K. Petersen Link: https://lore.kernel.org/r/20220303201312.3255347-6-kbusch@kernel.org Signed-off-by: Jens Axboe --- lib/gen_crc64table.c | 51 ++++++++++++++++++++++++++++++++++++++++----------- 1 file changed, 40 insertions(+), 11 deletions(-) (limited to 'lib/gen_crc64table.c') diff --git a/lib/gen_crc64table.c b/lib/gen_crc64table.c index 094b43aef8db..55e222acd0b8 100644 --- a/lib/gen_crc64table.c +++ b/lib/gen_crc64table.c @@ -17,10 +17,30 @@ #include #define CRC64_ECMA182_POLY 0x42F0E1EBA9EA3693ULL +#define CRC64_ROCKSOFT_POLY 0x9A6C9329AC4BC9B5ULL static uint64_t crc64_table[256] = {0}; +static uint64_t crc64_rocksoft_table[256] = {0}; -static void generate_crc64_table(void) +static void generate_reflected_crc64_table(uint64_t table[256], uint64_t poly) +{ + uint64_t i, j, c, crc; + + for (i = 0; i < 256; i++) { + crc = 0ULL; + c = i; + + for (j = 0; j < 8; j++) { + if ((crc ^ (c >> j)) & 1) + crc = (crc >> 1) ^ poly; + else + crc >>= 1; + } + table[i] = crc; + } +} + +static void generate_crc64_table(uint64_t table[256], uint64_t poly) { uint64_t i, j, c, crc; @@ -30,26 +50,22 @@ static void generate_crc64_table(void) for (j = 0; j < 8; j++) { if ((crc ^ c) & 0x8000000000000000ULL) - crc = (crc << 1) ^ CRC64_ECMA182_POLY; + crc = (crc << 1) ^ poly; else crc <<= 1; c <<= 1; } - crc64_table[i] = crc; + table[i] = crc; } } -static void print_crc64_table(void) +static void output_table(uint64_t table[256]) { int i; - printf("/* this file is generated - do not edit */\n\n"); - printf("#include \n"); - printf("#include \n\n"); - printf("static const u64 ____cacheline_aligned crc64table[256] = {\n"); for (i = 0; i < 256; i++) { - printf("\t0x%016" PRIx64 "ULL", crc64_table[i]); + printf("\t0x%016" PRIx64 "ULL", table[i]); if (i & 0x1) printf(",\n"); else @@ -58,9 +74,22 @@ static void print_crc64_table(void) printf("};\n"); } +static void print_crc64_tables(void) +{ + printf("/* this file is generated - do not edit */\n\n"); + printf("#include \n"); + printf("#include \n\n"); + printf("static const u64 ____cacheline_aligned crc64table[256] = {\n"); + output_table(crc64_table); + + printf("\nstatic const u64 ____cacheline_aligned crc64rocksofttable[256] = {\n"); + output_table(crc64_rocksoft_table); +} + int main(int argc, char *argv[]) { - generate_crc64_table(); - print_crc64_table(); + generate_crc64_table(crc64_table, CRC64_ECMA182_POLY); + generate_reflected_crc64_table(crc64_rocksoft_table, CRC64_ROCKSOFT_POLY); + print_crc64_tables(); return 0; } -- cgit